A real bond between atoms is always something hybrid between covalent, metallic and ionic.
In general, metallic and ionic bonds have atoms sharing electrons.
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Comment
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The bond types that are covered by this definition are the strong electonic bonds: covalent, metallic and ionic.
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Comment
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This class can be used to represent molecules as simplified quantum systems, in which outer molecule shared electrons are un-entangled with the inner shells of the atoms composing the molecule.
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Elucidation
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An bonded atom that shares at least one electron to the atom-based entity of which is part of.
Colloids are characterized by the occurring of the Tyndall effect on light.
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Elucidation
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A mixture in which one substance of microscopically dispersed insoluble or soluble particles (from 1 nm to 1 μm) is suspended throughout another substance and that does not settle, or would take a very long time to settle appreciably.
The subject of condensed matter physics that deals with the macroscopic and microscopic physical properties of matter, especially the solid and liquid phases which arise from electromagnetic forces between atoms. More generally, the subject deals with "condensed" phases of matter: systems of many constituents with strong interactions between them.
A continuum is made of a sufficient number of parts that it continues to exists as continuum individual even after the loss of one of them i.e. a continuum is a redundant.
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Comment
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A continuum is not necessarily small (i.e. composed by the minimum amount of sates to fulfill the definition).
A single continuum individual can be the whole fluid in a pipe.
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Comment
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A continuum is the bearer of properties that are generated by the interactions of parts such as viscosity and thermal or electrical conductivity.
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Elucidation
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A state that is a collection of sufficiently large number of other parts such that: - it is the bearer of qualities that can exists only by the fact that it is a sum of parts - the smallest partition dV of the state volume in which we are interested in, contains enough parts to be statistically consistent: n [#/m3] x dV [m3] >> 1
A material is a crystal if it has essentially a sharp diffraction pattern.
A solid is a crystal if it has essentially a sharp diffraction pattern. The word essentially means that most of the intensity of the diffraction is concentrated in relatively sharp Bragg peaks, besides the always present diffuse scattering. In all cases, the positions of the diffraction peaks can be expressed by
A instance of a material (e.g. nitrogen) can represent any state of matter. The fact that the individual also belongs to other classes (e.g. Gas) would reveal the actual form in which the material is found.
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Comment
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Material usually means some definite kind, quality, or quantity of matter, especially as intended for use.
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Elucidation
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The class of individuals standing for an amount of ordinary matter substance (or mixture of substances) in different states of matter or phases.
Phase heterogenous mixture may share the same state of matter.
For example, immiscibile liquid phases (e.g. oil and water) constitute a mixture whose phases are clearly separated but share the same state of matter.
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Elucidation
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A mixture in which more than one phases of matter cohexists.
In the physical sciences, a phase is a region of space (a thermodynamic system), throughout which all physical properties of a material are essentially uniform. Examples of physical properties include density, index of refraction, magnetization and chemical composition. A simple description is that a phase is a region of material that is chemically uniform, physically distinct, and (often) mechanically separable. In a system consisting of ice and water in a glass jar, the ice cubes are one phase, the water is a second phase, and the humid air is a third phase over the ice and water. The glass of the jar is another separate phase.
The term phase is sometimes used as a synonym for state of matter, but there can be several immiscible phases of the same state of matter. Also, the term phase is sometimes used to refer to a set of equilibrium states demarcated in terms of state variables such as pressure and temperature by a phase boundary on a phase diagram. Because phase boundaries relate to changes in the organization of matter, such as a change from liquid to solid or a more subtle change from one crystal structure to another, this latter usage is similar to the use of "phase" as a synonym for state of matter. However, the state of matter and phase diagram usages are not commensurate with the formal definition given above and the intended meaning must be determined in part from the context in which the term is used.
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Altlabel
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Phase
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Elucidation
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A matter object throughout which all physical properties of a material are essentially uniform.
A fluid in which a gas is ionized to a level where its electrical conductivity allows long-range electric and magnetic fields to dominate its behaviour.
A standalone atom can be bonded with other atoms by intermolecular forces (i.e. dipole–dipole, London dispersion force, hydrogen bonding), since this bonds does not involve electron sharing.
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Elucidation
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An atom that does not share electrons with other atoms.
In physics, a state of matter is one of the distinct forms in which matter can exist. Four states of matter are observable in everyday life: solid, liquid, gas, and plasma.
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Elucidation
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A superclass made as the disjoint union of all the form under which matter can exist.
An heterogeneous mixture that contains coarsly dispersed particles (no Tyndall effect), that generally tend to separate in time to the dispersion medium phase.
"Quantity in a conventionally chosen subset of a given system of quantities, where no quantity in the subset can be expressed in terms of the other quantities within that subset" ISO 80000-1
The superclass for all physical quantities classes that are categorized according to some domain of interests (e.g. metallurgy, chemistry), property (intensive/extensive) or application.
A property that is associated to an object by convention, or assumption.
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Elucidation
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A quantitative property attributed by agreement to a quantity for a given purpose.
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Example
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The thermal conductivity of a copper sample in my laboratory can be assumed to be the conductivity that appears in the vendor specification. This value has been obtained by measurement of a sample which is not the one I have in my laboratory. This conductivity value is then a conventional quantitiative property assigned to my sample through a semiotic process in which no actual measurement is done by my laboratory.
If I don't believe the vendor, then I can measure the actual thermal conductivity. I then perform a measurement process that semiotically assign another value for the conductivity, which is a measured property, since is part of a measurement process.
Then I have two different physical quantities that are properties thanks to two different semiotic processes.
Derived units are defined as products of powers of the base units corresponding to the relations defining the derived quantities in terms of the base quantities.
The current version of EMMO does not provide explicit classes for physical dimensions. Rather it embraces the fact that the physical dimensionality of a physical quantity is carried by its measurement unit.
The role of dimensional unit and its subclasses is to express the physical dimensionality that is carried by the unit.
Since the dimensionality of a physical quantity can be written as the product of powers of the physical dimensions of the base quantities in the selected system of quantities, the physical dimensionality of a measurement unit is uniquely determined by the exponents. For a dimensional unit, at least one of these exponents must be non-zero (making it disjoint from dimensionless units).
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Elucidation
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A subclass of measurement unit focusing on the physical dimensionality that is carried by the unit.
Quantities that are ratios of quantities of the same kind (for example length ratios and amount fractions) have the option of being expressed with units (m/m, mol/mol to aid the understanding of the quantity being expressed and also allow the use of SI prefixes, if this is desirable (μm/m, nmol/mol). -- SI Brochure
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Altlabel
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RatioUnit
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Elucidation
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Unit for fractions of quantities of the same kind, to aid the understanding of the quantity being expressed.
Note that logarithmic units like decibel or neper are not univocally defines, since their definition depends on whether they are used to measure a "power" or a "root-power" quantity.
It is advisory to create a uniquely defined subclass these units for concrete usage.
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Elucidation
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A logarithmic unit is a unit that can be used to express a quantity (physical or mathematical) on a logarithmic scale, that is, as being proportional to the value of a logarithm function applied to the ratio of the quantity and a reference quantity of the same type.
For a given unit system, measured constants are physical constants that are not used to define the unit system. Hence, these constants have to be measured and will therefore be associated with an uncertainty.
The specification of a measurand requires knowledge of the kind of quantity, description of the state of the phenomenon, body, or substance carrying the quantity, including any relevant component, and the chemical entities involved.
-- VIM
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Elucidation
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A quantity that is the result of a well-defined measurement procedure.
A measurement always implies a causal interaction between the object and the observer.
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Comment
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A measurement is the process of experimentally obtaining one or more measurement results that can reasonably be attributed to a quantity.
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Elucidation
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An 'observation' that results in a quantitative comparison of a 'property' of an 'object' with a standard reference based on a well defined mesurement procedure.
A measurement result generally contains “relevant information” about the set of measured quantity properties, such that some may be more representative of the measured quantity than others. This may be expressed in the form of a probability density function (pdf).
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Comment
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A measurement result has the measured quantity, measurement uncertainty and other relevant attributes as holistic parts.
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Elucidation
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Result of a measurement.
A set of quantites being attributed to a measurand (measured quantitative property) together with any other available relevant information, like measurement uncertainty.
"Real scalar quantity, defined and adopted by convention, with which any other quantity of the same kind can be compared to express the ratio of the second quantity to the first one as a number" ISO 80000-1
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Comment
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"Unit symbols are mathematical entities and not abbreviations."
"Symbols for units are treated as mathematical entities. In expressing the value of a quantity as the product of a numerical value and a unit, both the numerical value and the unit may be treated by the ordinary rules of algebra."
A set of one or more 'MeasuringInstruments' and often other devices, including any reagent and supply, assembled and adapted to give information used to generate 'MeasuredQuantityProperty' within specified intervals for quantities of specified kinds.
Metrology is the science of measurement and its application and includes all theoretical and practical aspects of measurement, whatever the measurement uncertainty and field of application (VIM3 2.2)
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Elucidation
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A language entity used in the metrology discipline.
A symbolic is recognized as reference unit also if it is not part of a quantity (e.g. as in the sentence "the Bq is the reference unit of Becquerel"). For this reason we can't declare the axiom: MetrologicalReference SubClassOf: inverse(hasMetrologicalReference) some Quantity because there exist reference units without being part of a quantity. This is peculiar to EMMO, where quantities as syntatic entities (explicit quantities) are distinct with quantities as semantic entities (properties).
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Elucidation
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A reference can be a measurement unit, a measurement procedure, a reference material, or a combination of such (VIM3 1.1 NOTE 2).
Metrological uncertainty in EMMO is a slight generalisation of the VIM term 'measurement uncertainty', which is defined as "a non-negative parameter characterising the dispersion of the quantity being measured".
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Comment
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In general, for a given set of information, it is understood that the measurement uncertainty is associated with a stated quantity value. A modification of this value results in a modification of the associated uncertainty.
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Comment
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Metrological uncertainty includes components arising from systematic effects, such as components associated with corrections and the assigned quantity values of measurement standards, as well as the definitional uncertainty. Sometimes estimated systematic effects are not corrected for but, instead, associated measurement uncertainty components are incorporated.
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Altlabel
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A metrological uncertainty can be assigned to any objective property via the 'hasMetrologicalUncertainty' relation.
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Elucidation
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The uncertainty of a quantity obtained through a well-defined procedure, characterising of the dispersion of the quantity.
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Example
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- Standard deviation - Half-width of an interval with a stated coverage probability
The word objective does not mean that each observation will provide the same results. It means that the observation followed a well defined procedure.
This class refers to what is commonly known as physical property, i.e. a measurable property of physical system, whether is quantifiable or not.
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Comment
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Subclasses of 'ObjectiveProperty' classify objects according to the type semiosis that is used to connect the property to the object (e.g. by measurement, by convention, by modelling).
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Altlabel
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PhysicalProperty
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Altlabel
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QuantitativeProperty
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Elucidation
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A quantity that is obtained from a well-defined procedure.
"Ordinal quantities, such as Rockwell C hardness, are usually not considered to be part of a system of quantities because they are related to other quantities through empirical relations only." International vocabulary of metrology (VIM)
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Elucidation
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"Quantity, defined by a conventional measurement procedure, for which a total ordering relation can be established, according to magnitude, with other quantities of the same kind, but for which no algebraic operations among those quantities exist" International vocabulary of metrology (VIM)
Physical constants are categorised into "exact" and measured constants.
With "exact" constants, we refer to physical constants that have an exact numerical value after the revision of the SI system that was enforsed May 2019.
In the same system of quantities, dim ρB = ML−3 is the quantity dimension of mass concentration of component B, and ML−3 is also the quantity dimension of mass density, ρ. ISO 80000-1
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Comment
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Measured or simulated 'physical propertiy'-s are always defined by a physical law, connected to a physical entity through a model perspective and measurement is done according to the same model.
Systems of units suggests that this is the correct approach, since except for the fundamental units (length, time, charge) every other unit is derived by mathematical relations between these fundamental units, implying a physical laws or definitions.
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Comment
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Measurement units of quantities of the same quantity dimension may be designated by the same name and symbol even when the quantities are not of the same kind.
For example, joule per kelvin and J/K are respectively the name and symbol of both a measurement unit of heat capacity and a measurement unit of entropy, which are generally not considered to be quantities of the same kind.
However, in some cases special measurement unit names are restricted to be used with quantities of specific kind only.
For example, the measurement unit ‘second to the power minus one’ (1/s) is called hertz (Hz) when used for frequencies and becquerel (Bq) when used for activities of radionuclides.
As another example, the joule (J) is used as a unit of energy, but never as a unit of moment of force, i.e. the newton metre (N · m).
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Comment
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— quantities of the same kind have the same quantity dimension, — quantities of different quantity dimensions are always of different kinds, and — quantities having the same quantity dimension are not necessarily of the same kind. ISO 80000-1
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Elucidation
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A 'Mathematical' entity that is made of a 'Numeral' and a 'MeasurementUnit' defined by a physical law, connected to a physical entity through a model perspective. Measurement is done according to the same model.
VIM defines a quantity as a "property of a phenomenon, body, or substance, where the property has a magnitude that can be expressed as a number and a reference".
A quantity in EMMO is a property and therefore only addresses the first part of the VIM definition (that is a property of a phenomenon, body, or substance). The second part (that it can be expressed as a number and a reference) is syntactic and addressed by emmo:QuantityValue.
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Altlabel
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Measurand
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Elucidation
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A quantifiable property of a phenomenon, body, or substance.
A quantity value is not necessarily a property, since it is possible to write "10 kg", without assigning this quantity to a specific object.
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Comment
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Following the International Vocabulary of Metrology (VIM), EMMO distinguishes between a quantity (a property) and the quantity value (a numerical and a reference).
So, for the EMMO the symbol "kg" is not a physical quantity but simply a 'Symbolic' object categorized as a 'MeasurementUnit'.
While the string "1 kg" is a 'QuantityValue'.
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Elucidation
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A symbolic that has parts a numerical object and a reference expressing the value of a quantity (expressed as the product of the numerical and the unit).
The Unified Code for Units of Measure (UCUM) is a code system intended to include all units of measures being contemporarily used in international science, engineering, and business. The purpose is to facilitate unambiguous electronic communication of quantities together with their units.
The UN/CEFACT Recommendation 20 provides three character alphabetic and alphanumeric codes for representing units of measurement for length, area, volume/capacity, mass (weight), time, and other quantities used in international trade. The codes are intended for use in manual and/or automated systems for the exchange of information between participants in international trade.
An expression that has parts only integer constants, variables, and the algebraic operations (addition, subtraction, multiplication, division and exponentiation by an exponent that is a rational number)
Array subclasses with a specific shape can be constructed with cardinality restrictions.
See Shape4x3Matrix as an example.
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Comment
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Arrays are ordered objects, since they are a subclasses of Arrangement.
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Elucidation
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Arrays are ordered mathematical objects who's elementary spatial parts are numbers. Their dimensionality is constructed with spatial direct parthood, where 1-dimensional arrays have spatial direct parts Number and n-dimensional array have spatial direct parts (n-1)-dimensional arrays.
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Example
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A Vector is a 1-dimensional Array with Number as spatial direct parts, a Matrix is a 2-dimensional Array with Vector as spatial direct parts, an Array3D is a 3-dimensional Array with Matrix as spatial direct parts, and so forth...
A mathematical object in this branch is not representing a concept but an actual graphical object built using mathematcal symbols arranged in some way, according to math conventions.
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Elucidation
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The class of general mathematical symbolic objects respecting mathematical syntactic rules.
A number individual provides the link between the ontology and the actual data, through the data property hasNumericalValue.
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Comment
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A number is actually a string (e.g. 1.4, 1e-8) of numerical digits and other symbols. However, in order not to increase complexity of the taxonomy and relations, here we take a number as an "atomic" object, without decomposit it in digits (i.e. we do not include digits in the EMMO as alphabet for numbers).
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Comment
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In math usually number and numeral are distinct concepts, the numeral being the symbol or a composition of symbols (e.g. 3.14, 010010, three) and the number is the idea behind it. More than one numeral stands for the same number. In the EMMO abstract entities do not exists, and numbers are simply defined by other numerals, so that a number is the class of all the numerals that are equivalent (e.g. 3 and 0011 are numerals that stands for the same number). Or alternatively, an integer numeral may also stands for a set of a specific cardinality (e.g. 3 stands for a set of three apples). Rational and real numbers are simply a syntactic arrangment of integers (digits, in decimal system). The fact that you can't give a name to a number without using a numeral or, in case of positive integers, without referring to a real world objects set with specific cardinality, suggests that the abstract concept of number is not a concept that can be practically used. For these reasons, the EMMO will consider numerals and numbers as the same concept.
A 'Mathematical' that has no unknown value, i.e. all its 'Variable"-s parts refers to a 'Number' (for scalars that have a built-in datatype) or to another 'Numerical' (for complex numerical data structures that should rely on external implementations).
Subclasses of 'Symbol' are alphabets, in formal languages terminology. A 'Symbol' is atomic for that alphabet, i.e. it has no parts that are symbols for the same alphabet. e.g. a math symbol is not made of other math symbols A Symbol may be a String in another language. e.g. "Bq" is the symbol for Becquerel units when dealing with metrology, or a string of "B" and "q" symbols when dealing with characters.
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Comment
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Symbols of a formal language need not be symbols of anything. For instance there are logical constants which do not refer to any idea, but rather serve as a form of punctuation in the language (e.g. parentheses).
Symbols of a formal language must be capable of being specified without any reference to any interpretation of them. (Wikipedia)
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Comment
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The class is the idea of the symbol, while the individual of that class stands for a specific mark (or token) of that idea.
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Altlabel
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AlphabeticEntity
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Elucidation
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The class of individuals that stand for an elementary mark of a specific symbolic code (alphabet).
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Example
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The class of letter "A" is the symbol as idea and the letter A that you see on the screen is the mark that can be represented by an individual belonging to "A".
This class collects individuals that represents arrangements of strings, or other symbolic compositions, without any particular predifined arrangement schema.
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Elucidation
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A symbolic entity made of other symbolic entities according to a specific spatial configuration.
A variable is a symbolic object that stands for any other mathematical object, such as number, a vector, a matrix, a function, the argument of a function, a set, an element of a set.
In SI are the physical dimensions of the base quantities time (T), length (L), mass (M), electric current (I), thermodynamic temperature (Θ), amount of substance (N) and luminous intensity (J).
In general the dimension of any quantity Q is written in the form of a dimensional product,
dim Q = T^α L^β M^γ I^δ Θ^ε N^ζ J^η
where the exponents α, β, γ, δ, ε, ζ and η, which are generally small integers, which can be positive, negative, or zero, are called the dimensional exponents. -- SI brouchure
The SI dimensional units are equivalent to dimensional strings that uniquely defines their dimensionality by specifying the values of the coefficients α, β, γ, δ, ε, ζ and η. A dimensional string is a space-separated string of the physical dimension symbols followed by the value of the exponent (including it sign). They should always match the following regular expression:
A collapse is a fundamental interaction between m colliding particles that results in a single outgoing particle (inverse decay) that is expressed as a complete bipartite directed graph K(m,1) with m>1.
A collapse is a fundamental process occurring to one particle that is expressed as a complete bipartite directed graph K(1,n) with n>1, being n the number of outgoing particles.
A chausal chain whose quantum parts are of the same standard model fundamental type.
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Conceptualisation
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An elementary particle is a causal chain of quantum entities of the same type. For example, an elementary electron is a sequence of fundamental electrons only.
A fundamental system is expressed as a complete bipartite directed graph K(m,n) of quantums, m being the number of originating quantums, and n being the receiving quantums.
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Elucidation
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A causal system that is the representation of a Feynman diagram, where quantum represents the real particles entering and exiting the system.
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Conceptualisation
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A fundamental physical process is made of one or more standard particles as input, and one or more standard particles as output, where each input is direct cause of each output. Each fundamental physical phenomena refers to a Feynman diagram, hence is made at least of three standard model particles. This requirement implies that a physical phenomena is either a decay, annihilation, interaction, collapse or creation phenomena (fundamental) or a composition of them (non-fundamental).
A chausal path whose quantum parts belongs to at least two different standard model fundamental types.
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Conceptualisation
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An multi-particle path is a causal path of quantum entities of different type, following the causal connection between an initial quantum up to the final one, regardless on the fact that causality is passing through elementary particles of different types. For example, a path starting from an elementary photon, then through the electron with which it scatter, and then trough a positron with which the electron collides.
A physically unbounded system is a combination of elementary particles chains tha may include also decays and/or annihilations, without any space-like interaction between elementary particles.
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Altlabel
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NonInteractingSystem
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Elucidation
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A causal multipath system is a system made of causal paths that are not interacting between each others, or possibly merge and fork.
The class of individuals representing causal clusters.
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Definition
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The disjoint union of the CausalSystem and Collection classes.
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Conceptualisation
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With the causal cluster term we address an heterogenous group of entities, which possess the common feature of having at least two causally non connected quanta. It comprises collections (non self-connected entities) and causal systems (entities extended in space).
The class of individuals representing causal particles.
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Definition
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The disjoint union of CausalPath and Quantum classes.
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Conceptualisation
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A causal particle represents the most elementary entity in physics, being it a simple state of an elementary particle, called quantum in the EMMO, or a chain of causally connected quanta.
The causal path class can be defined univocally in FOL.
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Altlabel
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CausalChain
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Altlabel
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Elementary
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Elucidation
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The class of entities that possess a temporal structure but no spatial structure.
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Example
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An electron with at least one causal interaction with another particle.
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Conceptualisation
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A causal chain is an ordered causal sequence of entities that does not host any bifurcation within itself (a chain). A chain can only be partitioned in time.
A causal structure expresses itself in time and space thanks to the underlying causality relations between its constituent quantum entities. It must at least provide two temporal parts. The unity criterion beyond the definition of a causal structure (the most general concept of structure) is the existence of an undirected causal path between each of its parts.
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Elucidation
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The class of individuals representing causally self-connected world entities.
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Definition
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The disjoint union of Causal Path and CausalSystem classes.
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Conceptualisation
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The most fundamental unity criterion for the definition of an structure is that: - is made of at least two quantums (a structure is not a simple entity) - all quantum parts form a causally connected graph
The class of individuals representing a causal system.
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Example
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A electron binded by a nucleus.
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Conceptualisation
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A causal system provides the most general concept of system, being a union of causal structures interacting together. In its most simple form, a causal system is an interlacement of causal paths (the most simple structure type). A causal system is always a spatial-like structure, and is represented as a multiple topologically orderable direct acyclic graph, with quanta as nodes and causality relations as edges.
The class of not direct causally self-connected world entities.
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Example
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The collection of users of a particular software, the collection of atoms that have been part of that just dissociated molecule.
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Conceptualisation
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A collection is the concept that complements the item concept, being an entity that possesses at least one part non directly causally connected with the rest. A collection can be partitioned in maximally connected items called members. The members are self-connected entities and there is no direct causality relation between them. The combination of collection and item concepts is the EMMO mereocausality alternative to set theory. However, two items can be members only if they are non direct causally connected, giving some constraints to a collection definition. For example, two entities which are directly connected cannot be two distinct members, while their interiors (i.e. the entities obtained by removing the layer of parts that provides the causal contact between them) can be.
EMMO entities dimensionality is related to their mereocausal structures. From the no-dimensional quantum entity, we introduce time dimension with the elementary concept, and the spacetime with the causal system concept. The EMMO conceptualisation does not allow the existence of space without a temporal dimension, the latter coming from a causal relation between entities. For this reason, the EMMO entities that are not quantum or elementaries, may be considered to be always spatiotemporal. The EMMO poses no constraints to the number of spatial dimensions for a causal system (except being higher than one).
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Elucidation
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The class of all the OWL individuals representing world entities according to EMMO conceptualisation.
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Definition
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The disjoint union of the fundamental mereocausal classes of Quantum, CausalPath, CausalSystem and Collection.
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Conceptualisation
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The EMMO conceptualises the world using the primitive concepts of causality and parthood. Parthood is about the composition of world entities starting from other more fundamental entities. Causality is about the interactions between world entities. The quantum is the smallest indivisible part of any world entity. Quantum individuals are the fundamental causal constituents of the universe, since it is implied that causality originates from quantum-to-quantum interactions. Quantums are no-dimensional, and their aggregation makes spacetime emerge from their causal structure. Causality between macro entities (i.e. entities made of more than one quantum) is explained as the sum of the causality relations between their quantum constituents. Fundamental interactions (quantum fields) are represented as symmetric causality between macro entities, while classical interactions are mediated by chain of quantums (i.e. elementary particles). The fundamental distinction between world entities is direct causality self-connectedness: a world entity can be self-connected xor not self-connected depending on the causality network of its fundamental components. Void regions do not exist in the EMMO, or in other words there is no spacetime without entities, since space and time are measured quantities following a causality relation between entities (spacetime emerges as relational property not as a self-standing entity). Entities are not placed in space or time: space and time are always relative between entities and are measured. In other words, space and time relations originates from causality interactions.
The concept of self-connectivity is applied using a 4D approach. Given that, the entity made of an electron and a proton that travel, interact, and then depart from each other is an item, since we don't focus only on the beginning or the end stage but to the overall 4D entity, being the interaction the connectivity bridge between the two particles.
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Altlabel
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CausalObject
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Elucidation
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The class of individuals standing for quantum or causally self-connected world entities.
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Example
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A person life, an interval of a person life. The lifetime of two components, from the production in separate manufacturing lines, their being connected components in a device, including their eparation and decommissioning.
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Definition
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The disjoint union of Particle and CausalStructure classes.
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Conceptualisation
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A world entity is direct causally self-connected if any two parts that make up the whole are direct causally connected to each other. In the EMMO, topological connectivity is based on causality. All physical objects, i.e. entities whose behaviour is explained by physics laws, are represented only by items. In other words, a physical object part is embedded in a direct causal graph that provides always a path between two of its parts. Members of a collection lack such direct causality connection, i.e. they do not constitute a physical object. Following graph theory concepts, the quantums of an item are all connected together within a network of causal relations, forming a connected causal graph. A collection is then a set of disconnected graphs.
A quantum is the EMMO mereological atomistic and causal reductionistic entity. To avoid confusion with the concept of atom coming from physics and to underline the causal reductionistic approach, we will use the expression quantum mereology, instead of atomistic mereology.
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Altlabel
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RealParticle
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Elucidation
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The class of the mereological and causal fundamental entities.
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Example
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From a physics perspective a quantum can be related to smallest identifiable entities, according to the limits imposed by the uncertainty principle in space and time measurements. However, the quantum mereotopology approach is not restricted only to physics. For example, in a manpower management ontology, a quantum can stand for an hour (time) of a worker (space) activity.
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Definition
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The class of entities without proper parts.
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Conceptualisation
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A quantum is the most fundamental item (both mereologically and causally) and is considered causally self-connected by definition. The quantum concept recalls the fact that there is lower epistemological limit to our knowledge of the universe, related to the uncertainity principle. Space and time emerge following the network of causal connections between quantum objects. So quantum objects are adimensional objects, that precede space and time dimensions: they are simple beings (in greek οντα). Using physics concepts, we can think the quantum as an elementary particle (e.g. an electron) in a specific state between two causal interactions. A quantum stands for an incoming or outcoming real particle in a Feynman diagram.
Causality in the EMMO is intended as physical causation and not counter-factual. Meaning that causality is an expression of actual physical interactions, and not of a counterfactual depence such as “I didn't water the flowers, hence, I'm the cause of their death”.
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Comment
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Each pair of entities is either in isCauseOf or isNotCauseOf relation. The two are mutually exclusive.
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Elucidation
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The superclass of all causal EMMO relations.
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Conceptualisation
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Causality is the fundamental concept describing how entities affect each other, and occurs before time and space relations. Embracing a strong reductionistic view, causality originates at quantum entities level.
A comment can be addressed to facilitate interpretation, to suggest possible usage, to clarify the concepts behind each entity with respect to other ontological apporaches.
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Elucidation
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A text that add some information about the entity.
A conceptualisation is the preliminary step behind each theory, preceding each logical formalisation. The readers approaching an ontology entity should first read the conceptualisation annotation to clearly understand "what we are talking about" and the accompanying terminology, and then read the elucidation.
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Comment
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An elucidation can provide references to external knowledge sources (i.e. ISO, Goldbook, RoMM).
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Elucidation
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The conceptualisation annotation is a comment that helps the reader to understand how the world has been conceptualised by the ontology authors.
The contact relation is not an ordering relation since is symmetric.
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Altlabel
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hasSpatialnteractionWith
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Elucidation
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An interaction that is the sum of direct causality relations between two entities that are interpretable as fundamental physical interactions.
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Example
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An elementary electron is in contact with another elementary electron in a scattering process.
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Example
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The laptop is in contact with the desk, since there is a double-directional causality.
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Conceptualisation
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A spatial contact between two entities occurs when the two entities are in an interaction relation whose causal structure is a representation of the fundamental interactions between elementary particles (Feynman diagrams). It means that if two entities are in contact, then there is at least a couple of elementary particles, one part of the first and one part of the second, interacting according to one of the fundamental interactions through virtual particles. This kind of connection is space-like (i.e. interconnecting force carrier particle is offshelf). Contacts between two entities exclude the possibility of other causal relations that are not included in a fundamental space-like interaction.
An elucidation should address the real world entities using the concepts introduced by the conceptualisation annotation.
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Elucidation
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Short enlightening explanation aimed to facilitate the user in drawing the connection (interpretation) between a OWL entity and the real world object(s) for which it stands.
The etymology annotation is usually applied to rdfs:label entities, to better understand the connection between a label and the concept it concisely represents.
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Elucidation
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The etymology annotation explains the origin of a word and the historical development of its meaning.
The relation between two individuals representing a collection and a non-maximal proper part, meaning the the latter is connected with the rest of the whole.
Each pair of entities in direct causality relation is either in hasNext or hasTwoWayCauseWith relation. The two are mutually exclusive.
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Comment
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This relation is asymmetric and irreflexive.
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Altlabel
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isBefore
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Elucidation
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A time contact occurs when x isDirectCause y and not(y isCauseOf x).
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Example
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My life between 18-24 years has next my life between 24-32 years.
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Example
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The raw sample has next the treated sampled, which has next the examined sample. In this sense the whole sample is made of three states, connected by the has next relation, following its evolution in time.
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Conceptualisation
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A temporal relation between two entities occurs when the two entities are in a one directional causality relation. The idea is that a temporal relation always implies a one-directional causality between two entities, leading to a asymmetric relation. This means that the causing entity can be in direct and optionally indirect causality relation with the effect entity. On the contrary, the effect entity cannot be in any causal relation (direct or indirect) with the causing entity.
A non-maximal part is a proper part that is connected with the rest of the whole.
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Altlabel
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hasNotMaximalPart
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Elucidation
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The relation between two individuals representing an entity and a non-maximal proper part, meaning the the latter is connected with the rest of the whole.
The proper part relation has the following pair-covering sub-relations: - hasMembers xor hasPiece - hasPortionPart xor hasGatheredPart . hasItemPart xor hasScatteredPart
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Elucidation
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The relation between an entity and one of its parts, when both entities are distinct.
A temporal part of an item cannot both cause and be caused by any other proper part of the item. A temporal part is not constraint to be causally self-connected, i.e. it can be either an item or a collection. We therefore introduce two subproperties in order to distinguish between both cases.
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Comment
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In EMMO FOL this is a defined property. In OWL temporal relations are primitive.
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Elucidation
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A relation that identify a proper item part of the whole, whose parts always cover the full spatial extension of the whole within a time interval.
The relation between two causally reachable entities through a path of contacts relations (i.e. representing physical interactions).
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Example
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I'm interacting with another tennis player through a ball. Or, two people in a webconference are interacting using a mediator which is the network signal.
Each pair of causally connected entities is either in isDirectCauseOf or isIndirectCauseOf relation. The two are mutually exclusive.
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Comment
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It applies to both quantums and macro-entities (entities made of more than one quantum). It is admissible for two entities to be one the cause of the other, excepts when they are both quantums.
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Comment
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The OWL 2 DL version of the EMMO introduces this object property as primitive causal relation. It refers to the macro causality relation mC(x,y), defined in the EMMO FOL version. While the EMMO FOL introduces the quantum causality relation C(x,y) as primitive, the OWL 2 DL version substantially simplifies the theory, neglecting these lower level relations that are well above DL expressivity.
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Elucidation
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The relation between an individuals x and y, that holds if and only if: a) y having a part that is causing an effect on a part of x b) y and x are non-overlapping
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Example
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John yesterday is the cause of John today, is an example of temporal-like causality. The desk supporting my laptop is a space-like causality.
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Conceptualisation
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We say that an entity causes another if there is a quantum part of the first that is in causal relation with a quantum parts of the second. An entity cannot cause itself (causal loops are forbidden) or a part of itself. For this reasons causality between entities excludes reflexivity and prevents them to overlap.
Direct cause provides the edges for the transitive restriction of the direct acyclic causal graph whose nodes are the quantum entities.
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Elucidation
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A causal relation between the causing and the effected entities occurring without intermediaries.
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Conceptualisation
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Direct causality is a concept that capture the idea of contact between two entities, given the fact that there are no causal intermediaries between them. It requires that at least a quantum of the causing entity is direct cause of a quantum of the caused entity. It does not exclude the possibility of indirect causal routes between proper parts of the two entities.
A causal relation between the effected and the causing entities with intermediaries.
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Conceptualisation
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An indirect cause is a relation between two entities that is mediated by a intermediate entity. In other words, there are no quantum parts of the causing entity that are direct cause of quantum parts of the caused entity.
A whole that represent the overall lifetime of the world object that represents according to some holistic criteria.
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Example
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A marathon is an example of class whose individuals are always maximal since the criteria satisfied by a marathon 4D entity poses some constraints on its temporal and spatial extent.
On the contrary, the class for a generic running process does not necessarily impose maximality to its individuals. A running individual is maximal only when it extends in time for the minimum amount required to identify a running act, so every possible temporal part is always a non-running.
Following the two examples, a marathon individual is a maximal that can be decomposed into running intervals. The marathon class is a subclass of running.
A perspective characterized by the belief that: - a whole is more than merely the sum of its parts (wholism) - the parts of a whole are interconnected in a way that can be explained only by reference to the whole (rolism).
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Example
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A molecule of a body can have role in the body evolution, without caring if its part of a specific organ and without specifying the time interval in which this role occurred.
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Example
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A product is a role that can be fulfilled by many objects, but always requires a process to which the product participates and from which it is generated.
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Definition
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The union of classes whole and part.
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Conceptualisation
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An holistic perspective considers each part of the whole as equally important, without the need to position the parts within a hierarchy (in time or space). The interest is on the whole object and on its parts (how they contribute to the whole, i.e. their roles), without going further into specifying the spatial hierarchy or the temporal position of each part.
This class allows the picking of parts without necessarily going trough a rigid hierarchy of spatial compositions (e.g. body -> organ -> cell -> molecule) or temporal composition. This is inline with the transitive nature of parthood, as it is usually defined in literature.
The holistic perspective is not excluding the reductionistic perspective, on the contrary it can be considered its complement.
A qualified role is an entity of a type that requires to be part of a another specific and different type. For example, a participant is always required to be part of a process, or a student always requires to be part of a school. This definition provides a clear and precise way to define what a role is.
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Elucidation
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The superclass for all classes whose entities are part of an entity of different type.
A qualified whole is an entity of a type that requires to have parts of a another specific and different type. For example, a process always requires to have a participant, or a car always requires to have a powertrain. This definition provides a clear and precise way to define what a whole is.
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Elucidation
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The superclass for all classes whose entities requires to have at least a part of different type.
A whole possessing some proper parts of its same type.
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Example
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An object A which is classified as water-fluid possesses a proper part B which is water itself if the lenght scale of the B is larger than the water intermolecular distance keeping it in the continuum range. In this sense, A is redundant.
If A is a water-fluid so small that its every proper part is no more a continuum object (i.e. no more a fluid), then A is fundamental.
In this class the concept of role and part are superimposed (the term part is also used to define the role played by an actor). Here entities are categorized according to their relation with the whole, i.e. how they contribute to make a specific whole, and not what they are as separate entities. This class is expected to host the definition of world objects as they appear in its relation with the surrounding whole (being a part implies being surrounded by something bigger to which it contributes).
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Altlabel
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HolisticPart
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Altlabel
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Part
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Elucidation
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An entity that is categorized according to its relation with a whole through a parthood relation and that contributes to it according to an holistic criterion, where the type of the whole is not the type of the part.
The class of individuals that satisfy a whole defining criteria (i.e. belongs to a subclass of whole) and have no spatial parts that satisfy that same criteria (no parts that are of the same type of the whole).
The class of individuals that satisfy a whole defining criteria (i.e. belongs to a subclass of whole) and have no proper parts that satisfy that same criteria (no parts that are of the same type of the whole).
The class of individuals that satisfy a whole defining criteria (i.e. belongs to a subclass of whole) and have no temporal parts that satisfy that same criteria (no parts that are of the same type of the whole).
A whole is always defined using a criterion expressed through the classical transitive parthood relation. This class is expected to host the definition of world objects as they appear in its wholeness, dependently on some of their parts and independently on the surroundings.
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Comment
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A whole is categorized as fundamental (or maximal) or redundant (non-maximal).
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Elucidation
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The superclass of entities which are defined by requiring the existence of some parts (at least one) of specifically given types, where the specified types are different with respect to the type of the whole.
The relation between the whole and a proper part of the whole that scale down to the point which it lose the characteristics of the whole and become something else.
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Example
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An holistic part of water fluid is a water molecule.
The purpose of this relation is to provide a parhood relation that does not go deep enough, in terms of decomposition, to break the holistic definition of the whole.
On the contrary, the holistic parthood, is expected to go that deep.
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Elucidation
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The superproperty of the relations between a whole and its mereological parts that are still holistic wholes of the same type.
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Example
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A volume of water has redundand parts other volumes of water. All this volumes have holistic parts some water molecules.
This relation is about two wholes that overlap, and whose intersection is an holistic part of both.
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Elucidation
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A relation between two holistic wholes that properly overlap, sharing one of their holistic parts.
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Example
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A man and the process of building a house. The man is a whole that possesses an holistic temporal part which is an interval of six monts and represents a working period in his lifetime. The process of building a house is a whole that possesses an holistic spatial part which is a builder. The working period of the man and the builder participating the building process are the same individual, belonging both to a man lifetime and to a building holistic views. In this sense, the man and the building process overcrosses. and the overlapping individual is represented differently in both holistic views.
A continuant (here called object) is usually defined as a whole whose all possible temporal parts are always satisfying a specific criterion (wich is the classical definition of continuants). However that's not possible in general, since we will finally end to temporal parts whose temporal extension is so small that the connectivity relations that define the object will no longer hold. That's the case when the temporal interval is lower than the interval that characterize the causality interactions between the object parts. In other terms, if the time span of a temporal part is lower than the inverse of the frequency of interactions between the constituents, then the constituents in such temporal part are not connected. The object is no more an object, neither an item, but simply a collection of fundamental parts. To overcome this issue, we can identify an minimum holistic temporal part (a lower time interval value), below which a specific definition for an object type does not hold anymore, that is called a fundamental.
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Altlabel
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Continuant
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Altlabel
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Endurant
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Elucidation
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A whole that is identified according to a criteria based on its spatial configuration that is satisfied throughout its time extension.
The interest is on the 4D object as it extends in time (process) or as it persists in time (object): - object (focus on spatial configuration) - process (focus on temporal evolution)
The concepts of endurant and perdurant implicitly rely on the concept of instantaneous 3D snapshot of the world object, that in the EMMO is not allowed since everything extends in 4D and there are no abstract objects. Moreover, time is a measured property in the EMMO and not an objective characteristic of an object, and cannot be used as temporal index to identify endurant position in time.
For this reason an individual in the EMMO can always be classified both endurant and perdurant, due to its nature of 4D entity (e.g. an individual may belong both to the class of runners and the class of running process), and the distinction is purely semantic. In fact, the object/process distinction is simply a matter of convenience in a 4D approach since a temporal extension is always the case, and stationarity depends upon observer time scale. For this reason, the same individual (4D object) may play the role of a process or of an object class depending on the object to which it relates.
Nevertheless, it is useful to introduce categorizations that characterize persistency through continuant and occurrent concepts, even if not ontologically but only cognitively defined. This is also due to the fact that our language distinguish between nouns and verbs to address things, forcing the separation between things that happens and things that persist.
This perspective provides classes conceptually similar to the concepts of endurant and perdurant (a.k.a. continuant and occurrent). We claim that this distinction is motivated by our cognitive bias, and we do not commit to the fact that both these kinds of entity “do really exist”. For this reason, a whole instance can be both process and object, according to different cognitive approaches (see Wonderweb D17).
The distinction between endurant and perdurant as usually introduced in literature (see BFO SPAN/SNAP approach) is then no more ontological, but can still be expressed through the introduction of ad hoc primitive definitions that follow the interpreter endurantist or perdurantist attitude.
A process can be defined only according to an entity type. The minimum process is an entity made of two entities of the same type that are temporally related.
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Comment
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Following the common definition of process, the reader may think that every whole should be a process, since every 4D object always has a time dimension. However, in the EMMO we restrict the meaning of the word process to items whose evolution in time have a particular meaning for the ontologist (i.e. every 4D object unfolds in time, but not every 4D time unfolding may be of interest for the ontologist and categorized as a process).
For this reason, the definition of every specific process subclass requires the introduction of a primitive concept.
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Altlabel
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Occurrent
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Altlabel
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Perdurant
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Elucidation
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A whole that is identified according to a criteria based on its temporal evolution that is satisfied throughout its time extension.
The subclass of icon inspired by Peirceian category (b) the diagram, whose internal relations, mainly dyadic or so taken, represent by analogy (with the same logic) the relations in something (e.g. math formula, geometric flowchart).
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Elucidation
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An icon that represents the internal logical structure of the object.
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Example
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A physics equation is replicating the mechanisms internal to the object.
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Example
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Electrical diagram is diagrammatic and resemblance
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Example
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MODA and CHADA are diagrammatic representation of a simulation or a characterisation workflow.
A conventional referring to an object according to a specific code that reflects the results of a specific interaction mechanism and is shared between other interpreters. A coded is always a partial representation of an object since it reflects the object capability to be part of a specific determination. A coded is a sort of name or label that we put upon objects that interact with an determiner in the same specific way.
For example, "hot" objects are objects that interact with an observer through a perception mechanism aimed to perceive an heat source. The code is made of terms such as "hot", "warm", "cold", that commonly refer to the perception of heat.
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Comment
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Let's define the class Colour as the subclass of the coded signs that involve photon emission and electromagnetic radiation sensible observers. An individual C of this class Colour can be defined be declaring the process individual (e.g. daylight illumination) and the observer (e.g. my eyes) Stating that an entity E hasCoded C, we mean that it can be observed by such setup of process + observer (i.e. observed by my eyes under daylight). This definition can be specialised for human eye perception, so that the observer can be a generic human, or to camera perception so that the observer can be a device. This can be used in material characterization, to define exactly the type of measurement done, including the instrument type.
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Elucidation
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A conventional that stands for an object according to a code of interpretation to which the interpreter refers.
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Example
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A biography that makes use of a code that is provided by the meaning of the element of the language used by the author.
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Example
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The name "red" that stands for the color of an object.
In Peirce semiotics this kind of sign category is called symbol. However, since symbol is also used in formal languages, the name is changed in conventional.
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Elucidation
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A 'Sign' that stands for an 'Object' through convention, norm or habit, without any resemblance to it.
An interpreter who establish the connection between an conventional sign and an object according to a specific convention.
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Example
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A scientist that assigns a quantity to a physical objects without actually measuring it but taking it for granted due to its previous experience (e.g. considering an electron charge as 1.6027663e-19 C, assigning a molecular mass to a gas only by the fact of a name on the bottle).
A 'Semiosis' that involves an 'Observer' that perceives another 'Physical' (the 'Object') through a specific perception mechanism and produces a 'Property' (the 'Sign') that stands for the result of that particular perception according to a well defined conventional procedure.
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Example
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Assigning the word "red" as sign for an object provides an information to all other interpreters about the outcome of a specific observation procedure according to the determiner.
An 'interpreter' that perceives another 'entity' (the 'object') through a specific perception mechanism and produces a 'property' (the 'sign') that stands for the result of that particular perception.
A characteriser that declares a property for an object without actually interact with it with the specific interaction required by the property definition (i.e. infer a property from other properties).
This subclass of icon inspired by Peirceian category (c) the metaphor, which represents the representative character of a sign by representing a parallelism in something else.
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Elucidation
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An icon that imitates one representative character of the object. It share external similarities with the object, but not necessarily the same internal logical structure.
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Example
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A data based model is only a functional icon, since it provide the same relations between the properties of the object (e.g., it can predict some properties as function of others) but is not considering the internal mechanisms (i.e., it can ignore the physics).
If object and sign belongs to the same class, then the sign is fuctional, diagrammatic and resemblance. For example, when a Boeing 747 is used as a sign for another Boeing 747.
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Comment
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In Peirce semiotics three subtypes of icon are possible: (a) the image, which depends on a simple quality (e.g. picture) (b) the diagram, whose internal relations, mainly dyadic or so taken, represent by analogy the relations in something (e.g. math formula, geometric flowchart) (c) the metaphor, which represents the representative character of a sign by representing a parallelism in something else [Wikipedia]
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Altlabel
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Model
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Altlabel
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Simulacrum
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Elucidation
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A sign that stands for an object by resembling or imitating it, in shape, function or by sharing a similar logical structure.
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Example
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A picture that reproduces the aspect of a person.
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Example
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An equation that reproduces the logical connection of the properties of a physical entity.
The interpreter is not the ontologist, being the ontologist acting outside the ontology at the meta-ontology level.
On the contrary, the interpreter is an agent recognized by the ontologist. The semiotic branch of the EMMO is the tool used by the ontologist to represent an interpreter's semiotic activity.
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Elucidation
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The entity (or agent, or observer, or cognitive entity) who connects 'Sign', 'Interpretant' and 'Object'.
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Example
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For example, the ontologist may be interest in cataloguing in the EMMO how the same object (e.g. a cat) is addressed using different signs (e.g. cat, gatto, chat) by different interpreters (e.g. english, italian or french people).
The same applies for the results of measurements: the ontologist may be interest to represent in the EMMO how different measurement processes (i.e. semiosis) lead to different quantitative results (i.e. signs) according to different measurement devices (i.e. interpreters).
A property is atomic in the sense that is aimed to deliver one and one only aspect of the object according to one code, such as the color with one sign (e.g., black) or a quantitiative property (e.g., 1.4 kg).
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Elucidation
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A coded that makes use of an atomic symbol with respect to the code used to refer to the interaction.
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Example
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Hardness is a subclass of properties. Vickers hardness is a subclass of hardness that involves the procedures and instruments defined by the standard hardness test.
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Example
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The name "red" which is atomic in the code made of the list of colors.
Semiotic subclasse are defined using Peirce's semiotic theory.
"Namely, a sign is something, A, which brings something, B, its interpretant sign determined or created by it, into the same sort of correspondence with something, C, its object, as that in which itself stands to C." (Peirce 1902, NEM 4, 20–21).
The triadic elements: - 'sign': the sign A (e.g. a name) - 'interpretant': the sign B as the effects of the sign A on the interpreter (e.g. the mental concept of what a name means) - 'object': the object C (e.g. the entity to which the sign A and B refer to)
This class includes also the 'interpeter' i.e. the entity that connects the 'sign' to the 'object'
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Elucidation
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The class of individuals that stands for semiotic objects, i.e. objects that take part on a semiotic process.
Here is assumed that the concept of 'object' is always relative to a 'semiotic' process. An 'object' does not exists per se, but it's always part of an interpretation.
The EMMO relies on strong reductionism, i.e. everything real is a formless collection of elementary particles: we give a meaning to real world entities only by giving them boundaries and defining them using 'sign'-s.
In this way the 'sign'-ed entity becomes an 'object', and the 'object' is the basic entity needed in order to apply a logical formalism to the real world entities (i.e. we can speak of it through its sign, and use logics on it through its sign).
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Altlabel
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Object
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Elucidation
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The object, in Peirce semiotics, as participant to a semiotic process.
A 'Sign' can have temporal-direct-parts which are 'Sign' themselves.
A 'Sign' usually havs 'sign' spatial direct parts only up to a certain elementary semiotic level, in which the part is only a 'Physical' and no more a 'Sign' (i.e. it stands for nothing). This elementary semiotic level is peculiar to each particular system of signs (e.g. text, painting).
Just like an 'Elementary' in the 'Physical' branch, each 'Sign' branch should have an a-tomistic mereological part.
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Comment
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According to Peirce, 'Sign' includes three subcategories: - symbols: that stand for an object through convention - indeces: that stand for an object due to causal continguity - icons: that stand for an object due to similitudes e.g. in shape or composition
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Elucidation
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An 'Physical' that is used as sign ("semeion" in greek) that stands for another 'Physical' through an semiotic process.
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Example
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A novel is made of chapters, paragraphs, sentences, words and characters (in a direct parthood mereological hierarchy).
Each of them are 'sign'-s.
A character can be the a-tomistic 'sign' for the class of texts.
The horizontal segment in the character "A" is direct part of "A" but it is not a 'sign' itself.
For plain text we can propose the ASCII symbols, for math the fundamental math symbols.
The word subjective applies to property intrisically subjective or non-well defined. In general, when an black-box-like procedure is used for the definition of the property.
This happens due to e.g. the complexity of the object, the lack of a underlying model for the representation of the object, the non-well specified meaning of the property symbols.
A 'SubjectiveProperty' cannot be used to univocally compare 'Object'-s.
e.g. you cannot evaluate the beauty of a person on objective basis.
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Elucidation
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A coded conventional that cannot be univocally determined and depends on an agent (e.g. a human individual, a community) acting as black-box.
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Example
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The beauty of that girl. The style of your clothing.
An agent is not necessarily human. An agent plays an active role within the process. An agent is a participant of a process that would not occur without it.
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Elucidation
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A participant that is the driver of the process.
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Example
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A catalyst. A bus driver. A substance that is initiating a reaction that would not occur without its presence.
A system is conceived as an aggregate of things that 'work' (or interact) together. While a system extends in time through distinct temporal parts (like every other 4D object), this elucdation focuses on a timescale in which the obejct shows a persistence in time.
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Elucidation
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An object that is made of a set of sub objects working together as parts of a mechanism or an interconnecting network (natural or artificial); a complex whole.
Intentionality is not limited to human agents, but in general to all agents that have the capacity to decide to act in driving a process according to a motivation.
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Elucidation
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An agent that is driven by the intention to reach a defined objective in driving a process.
A procedure can be considered as an intentional process with a plan.
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Altlabel
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Elaboration
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Altlabel
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Work
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Elucidation
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The process in which an agent works with some entities according to some existing formalised operative rules.
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Example
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The process in which a control unit of a CPU (the agent) orchestrates some cached binary data according to a list of instructions (e.g. a program). The process in which a librarian order books alphabetically on a shelf. The execution of an algorithm.
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Conceptualisation
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The set of established forms or methods of an organized body for accomplishing a certain task or tasks (Wiktionary).
Here we consider a temporal interval that is lower than the characteristic time of the physical process that provides the causality connection between the object parts.
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Elucidation
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An object which is an holistic temporal part of another object.
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Example
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If an inhabited house is considered as an house that is occupied by some people in its majority of time, then an interval of inhabited house in which occasionally nobody is in there is no more an inhabited house, but an unhinabited house, since this temporal part does not satisfy the criteria of the whole.
Participation is a parthood relation: you must be part of the process to contribute to it. A participant whose 4D extension is totally contained within the process.
Participation is not under direct parthood since a process is not strictly related to reductionism, but it's a way to categorize temporal regions by the interpreters.
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Elucidation
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The relation between a process and an object participating to it, i.e. that is relevant to the process itself.
The relation between a object whole and its spatial part of the same type.
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Example
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A volume of 1 cc of milk within a 1 litre can be considered still milk as a whole. If you scale down to a cluster of molecules, than the milk cannot be considered a fluid no more (and then no more a milk).
This term is often used in a non-technical context synonymously with additive manufacturing and, in these cases, typically associated with machines used for non-industrial purposes including personal use.
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Comment
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fabrication of objects through the deposition of a material using a print head, nozzle or another printer technology Note 1 to entry: This term is often used in a non-technical context synonymously with additive manufacturing (3.1.2) and, in these cases, typically associated with machines used for non-industrial purposes including personal use.
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Elucidation
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Fabrication of objects through the deposition of a material using a print head, nozzle or another printer technology.
Manufacturing by separating particles of material from a solid body by non-mechanical means. Ablation refers both to the removal of layers of material and to the separation of workpiece parts. The production process of ablation is considered in its stationary instantaneous state, independently of the application of auxiliary processes necessary to initiate the process. Ablation is divided into three subgroups according to the order point of view (OGP) "process in the effective zone on the surface of the workpiece": - thermal ablation; - chemical ablation; - electrochemical ablation.
process of joining materials to make parts from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing (3.1.29) and formative manufacturing methodologies,
heat treatment consisting of heating and soaking at a suitable temperature, followed by cooling under conditions such that, after return to ambient temperature, the metal will be in a structural state closer to that of equilibrium
Archetype join attaches two workpiece with geometrically defined shape together, using supplementary workpiece made of amorphous material (e.g. powder).
A manufacturing in which the product is a solid body with a well defined geometrical shape made from shapeless original material parts, whose cohesion is created during the process.
Treatment carried out after hardening or case hardening consisting of cooling to a temperature below room temperature to complete the transformation of austenite to martensite
Machining in which a tool is used whose number of cutting edges, geometry of the cutting wedges and position of the cutting edges in relation to the workpiece are determined
An object which is instrumental for reaching a particular purpose through its characteristic functioning process, with particular reference to mechanical or electronic equipment.
machining with a circular cutting movement in which the axis of rotation of the tool and the axis of the internal surface to be produced are identical and the feed movement is in the direction of this axis. The axis of rotation of the cutting movement maintains its position relative to the workpiece independently of the feed movement (axis of rotation workpiece-bound).
Free forming is pressure forming with tools that do not or only partially contain the shape of the workpiece and move against each other.
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Comment
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Non la metterei
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Comment
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Printing forms with tools that do not or only partially contain the shape of the workpiece and move against each other. The workpiece shape is created by free or fixed relative movement between the tool and the workpiece (kinematic shape generation).
Strengthening by rolling is the strengthening of component surfaces by mechanically generating compressive stresses in the component surface and consolidating the material.
Heat to a temperature appropriate for the particular material, maintain at that temperature and then cool at an appropriate rate to reduce hardness, improve machinability or achieve desired properties.
The permanent joining or other bringing together of two or more workpieces of a geometric shape or of similar workpieces with shapeless material. In each case, the cohesion is created locally and increased as a whole.
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Altlabel
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Fügen
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Elucidation
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A manufacturing involving the creation of long-term connection of several workpieces.
Is not simply a collection of machineries, since the connection between them is due to the parallel flow of processed parts that comes from a unique source and ends into a common repository.
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Elucidation
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A group of machineries used to process a group of similar parts.
A strict fundamental object overcrossing a manufacturing process, the intersection being the agent that participates and drives the manufacturing process.
The process of transforming precursor objects (e.g. raw materials) into a product by the use of manual labor, machinery or chemical/biological processes.
Manufacturing by changing the properties of the material of which a workpiece is made, which is done, among other things, by changes in the submicroscopic or atomic range, e.g. by diffusion of atoms, generation and movement of dislocations in the atomic lattice or chemical reactions, and where unavoidable changes in shape are not part of the essence of these processes.
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Comment
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esce workpiece
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Altlabel
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Stoffeigenschaft ändern
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Altlabel
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WorkPieceTreatment
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Elucidation
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The processing of a material aimed to transform its structure by means of any type of treatment, without involving relevant synthesis phenomena.
A material process requires the output to be classified as an individual of a material subclass.
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Altlabel
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ContinuumManufacturing
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Elucidation
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A manufacturing process aimed to modify the precursor objects through a physical process (involving other materials, energy, manipulation) to change its material properties.
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Example
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Synthesis of materials, quenching, the preparation of a cake, tempering of a steel beam.
Machining with a circular cutting movement, usually associated with a multi-toothed tool, and with a feed movement perpendicular or oblique to the axis of rotation of the tool, to produce any workpiece surface.
Free forming is pressure forming with tools that do not or only partially contain the shape of the workpiece and move against each other (from: DIN 8583 Part 3/05.70).
Nailing is joining by hammering or pressing nails (wire pins) as auxiliary parts into the solid material. Several parts are joined by pressing them together (from: DIN 8593 part 3/09.85).
(according to DIN 8200) Shot peening to generate residual compressive stresses in layers of the blasting material close to the surface in order to improve certain component properties, e.g. fatigue strength, corrosion resistance, wear resistance (from: DIN 8200:1982)
Type of scratching behaviour where the scratching force and the (displacement) deflection of the scratching tip are constant over the scratching distance during the test.
A collective term for the processes in which, during joining, the parts to be joined and any auxiliary parts are essentially only elastically deformed and unintentional loosening is prevented by frictional connection.
Deals with entities that have a undefined shape. Undefined means that the actual shape of the entity that is produced is not relevant for the definition of the process. In fact, everything has a shape, but in process engineering this is not relevant.
e.g. the fact that steel comes in sheets is not relevant for the definition of steel material generated in a steel-making process.
This concepts encompass the overall lifetime of a product. Is temporaly fundamental, meaning that it can have other products as holistic spatial parts, but its holistic temporal parts are not products. In other words, the individual must encompass the whole lifetime from creation to disposal. A product can be a tangible object (e.g. a manufactured object), a process (e.g. service). It can be the outcome of a natural or an artificially driven process. It must have and initial stage of its life that is also an outcome of a intentional process.
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Altlabel
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Output
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Elucidation
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The overall lifetime of an holistic that has been the output of an intentional process.
The mass of the raw part is equal to the mass of the finished part.
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Altlabel
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Forming
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Altlabel
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Umformen
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Elucidation
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A manufacturing in which workpieces are produced from solid raw parts through permanent deformation, provided that neither material is added nor removed.
Continuous or stepwise pressure forming with one or more rotating tools (rollers), without or with additional tools, e.g. plugs or mandrels, rods, guide tools
A manufacturing process in which the shape of a workpiece is changed by breaking the material cohesion at the processing point and thus the material cohesion is reduced overall.
Sintering occurs naturally in mineral deposits, and is used as a manufacturing process for materials including ceramics, metals and plastics. Because the sintering temperature doesn’t reach the materials’ melting point, it is often used for materials with high melting points, such as molybdenum and tungsten.
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Altlabel
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Sintern
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Elucidation
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Sintering is the process of forming a solid mass of material through heat and pressure without melting to the point of liquefaction. This process involves the atoms in materials diffusing across the particle boundaries and fusing together into one piece.
A manufacturing process in which metallic material is anodically dissolved under the influence of an electric current and an electrolyte solution. The current flow can be caused either by connection to an external current source or due to local element formation on the workpiece (etching).
Conversion of materials and assembly of components for the manufacture of products
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Comment
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Technology is the application of knowledge for achieving practical goals in a reproducible way.
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Comment
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Technology refers to methods, systems, and devices which are the result of scientific knowledge being used for practical purposes.
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Comment
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application of scientific knowledge, tools, techniques, crafts or systems in order to solve a problem or to achieve an objective which can result in a product or process
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Comment
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application of scientific knowledge, tools, techniques, crafts, systems or methods of organization in order to solve a problem or achieve an objective
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Altlabel
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ProductionEngineeringProcess
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Elucidation
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Class that includes the application of scientific knowledge, tools and techniques in order to transform a precursor object (ex. conversion of material) following a practic purpose.
Process consisting of two steps: - first, the steel is heated in a quenching treatment to a temperature above Ac3 and then rapidly cooled in a liquid to produce a process-specific grain structure; - subsequently, the steel is heated to a specific temperature during tempering to set the desired property and cooled in air.
Thermal ablation is the separation of material particles in solid, liquid or gaseous state by heat processes as well as the removal of these material particles by mechanical or electromagnetic forces (from: DIN
Joining process by softening the surfaces to be joined, either by heat or with a solvent (swelling welding, solvent welding), and pressing the softened surfaces together.
A solid is defined as a portion of matter that is in a condensed state characterised by resistance to deformation and volume changes.
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Comment
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In manufacturing, a workpiece is a single, delimited part of largely solid material that is processed in some form (e.g. stone ).
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Comment
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In physics, a rigid body (also known as a rigid object[2]) is a solid body in which deformation is zero or so small it can be neglected. The distance between any two given points on a rigid body remains constant in time regardless of external forces or moments exerted on it. A rigid body is usually considered as a continuous distribution of mass.
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Comment
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It has a shape, so we conclude that it is solid
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Comment
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Object that is processed with a machine
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Comment
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Seems to have to be processed through mechanical deformation. So it takes part of a manufacturing process. It is a Manufactured Product and it can be a Commercial Product
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Comment
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The raw material or partially finished piece that is shaped by performing various operations.
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Comment
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They are not powders or threads
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Comment
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a physical artifact, real or virtual, intended for subsequent transformation within some manufacturing operation
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Comment
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fili e polveri non sono compresi
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Comment
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it seems to be an intermediate product, that has to reach the final shape.
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Comment
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it seems to be solid, so it has a proper shape
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Comment
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powder is not workpiece because it has the shape of the recipient containing them
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Altlabel
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Werkstück
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Elucidation
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A WorkPiece is physical artifact, that has a proper shape and occupyes a proper volume intended for subsequent transformation. It is a condensed state, so it is a compact body that is processed or has to be processed.
A manufacturing in which it is formed a solid body with its shape from shapeless original material parts, whose cohesion is created during the process.
volume ratio consisting of the 0.000 001-fold of the power of the SI base unit metre with the exponent 3 divided by the power of the SI base unit metre with the exponent 3
volume ratio consisting of the 0.000 001-fold of the power of the SI base unit metre with the exponent 3 divided by the power of the SI base unit metre with the exponent 3
A unit that is the 0.000001-fold of the power of the SI base unit metre with the exponent 3 divided by the SI base unit mol multiplied by the SI base unit second.
-- QUDT
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Elucidation
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A unit that is the SI base unit metre with the exponent 3 divided by the SI base unit mol multiplied by the SI base unit second.
volume ratio consisting of the 0.001-fold of the power of the SI base unit metre with the exponent 3 divided by the power of the SI base unit metre with the exponent 3
volume ratio consisting of the 0.000000001-fold of the power of the SI base unit metre with the exponent 3 divided by the power of the SI base unit metre with the exponent 3
is the SI unit of magnetic field strength. One ampere per meter is equal to π/250 oersteds (12.566 371 millioersteds) in CGS units. The ampere per meter is also the SI unit of "magnetization" in the sense of magnetic dipole moment per unit volume; in this context 1 A/m = 0.001 emu per cubic centimeter.
"Becquerel per Kilogram" is used to describe radioactivity, which is often expressed in becquerels per unit of volume or weight, to express how much radioactive material is contained in a sample.
The candela per square metre (cd/m²) is the derived SI unit of luminance. The unit is based on the candela, the SI unit of luminous intensity, and the square metre, the SI unit of area. Nit (nt) is a deprecated non-SI name also used for this unit (1 nit = 1 cd/m²). As a measure of light emitted per unit area, this unit is frequently used to specify the brightness of a display device. Most consumer desktop liquid crystal displays have luminances of 200 to 300 cd/m²; the sRGB spec for monitors targets 80 cd/m2. HDTVs range from 450 to about 1000 cd/m2. Typically, calibrated monitors should have a brightness of 120 cd/m². Nit is believed to come from the Latin word nitere, to shine.
It is also known as atomic unit, u.a., au, ua. This unit is commonly used in the SI unit system. Coulomb Meter (C-m) has a dimension of LTI where L is length, T is time, and I is electric current. This unit is the standard SI unit in this category.
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Elucidation
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Coulomb Meter (C-m) is a unit in the category of Electric dipole moment. It is also known as atomic unit, u.a., au, ua. This unit is commonly used in the SI unit system. Coulomb Meter (C-m) has a dimension of LTI where L is length, T is time, and I is electric current. This unit is the standard SI unit in this category.
Coulomb Per Cubic Meter (C/m³) is a unit in the category of Electric charge density. It is also known as coulomb per cubic metre, coulombs per cubic meter, coulombs per cubic metre, coulomb/cubic meter, coulomb/cubic metre. This unit is commonly used in the SI unit system. Coulomb Per Cubic Meter has a dimension of L⁻³TI where L is length, T is time, and I is electric current. This unit is the standard SI unit in this category.
`Coulomb Per Kilogram (C/kg)` is the unit in the category of Exposure. It is also known as coulombs per kilogram, coulomb/kilogram. This unit is commonly used in the SI unit system. Coulomb Per Kilogram (C/kg) has a dimension of M⁻¹TI where M is mass, T is time, and I is electric current. This unit is the standard SI unit in this category.
(C/mol) is a unit in the category of Molar electric charge. It is also known as coulombs/mol. Coulomb Per Mol has a dimension of TN{-1}I where T is time, N is amount of substance, and I is electric current. This unit is the standard SI unit in this category.
Coulomb Per Square Meter (C/m²) is a unit in the category of Electric charge surface density. It is also known as coulombs per square meter, coulomb per square metre, coulombs per square metre, coulomb/square meter, coulomb/square metre. This unit is commonly used in the SI unit system. Coulomb Per Square Meter (C/m2) has a dimension of L⁻²TI where L is length, T is time, and I is electric current. This unit is the standard SI unit in this category.
Coulomb Square Meter (C-m2) is a unit in the category of Electric quadrupole moment. This unit is commonly used in the SI unit system. Coulomb Square Meter (C-m2) has a dimension of L2TI where L is length, T is time, and I is electric current. This unit is the standard SI unit in this category.
The SI unit of volume, equal to 1.0e6 cm3, 1000 liters, 35.3147 ft3, or 1.30795 yd3. A cubic meter holds about 264.17 U.S. liquid gallons or 219.99 British Imperial gallons.
Cubic Meter Per Kilogram (m3/kg) is a unit in the category of Specific volume. It is also known as cubic meters per kilogram, cubic metre per kilogram, cubic metres per kilogram, cubic meter/kilogram, cubic metre/kilogram. This unit is commonly used in the SI unit system. Cubic Meter Per Kilogram (m3/kg) has a dimension of M-1L3 where M is mass, and L is length. This unit is the standard SI unit in this category.
The molar volume, symbol Vm, is the volume occupied by one mole of a substance (chemical element or chemical compound) at a given temperature and pressure. It is equal to the molar mass (M) divided by the mass density. It has the SI unit cubic metres per mole m3/mol, although it is more practical to use the units cubic decimetres per mole dm3/mol for gases and cubic centimetres per mole cm3/mol for liquids and solids.
A cubic metre per second (m³s⁻¹, m³/s), cumecs or cubic meter per second in American English) is a derived SI unit of flow rate equal to that of a stere or cube with sides of one metre ( u0303 39.37 in) in length exchanged or moving each second. It is popularly used for water flow, especially in rivers and streams, and fractions for HVAC values measuring air flow.
Farad Per Meter (F/m) is a unit in the category of Electric permittivity. It is also known as farad/meter. This unit is commonly used in the SI unit system. Farad Per Meter has a dimension of M-1L-3T4I2 where M is mass, L is length, T is time, and I is electric current. This unit is the standard SI unit in this category.
The henry per meter (symbolized H/m) is the unit of magnetic permeability in the International System of Units ( SI ). Reduced to base units in SI, 1 H/m is the equivalent of one kilogram meter per square second per square ampere.
In the Hertz per Volt standard the frequency of the note is directly related to the voltage. A pitch of a note goes up one octave when its frequency doubles, meaning that the voltage will have to double for every octave rise. Depending on the footage (octave) selected, nominally one volt gives 1000Hz, two volts 2000Hz and so on. In terms of notes, bottom C would be 0.25 volts, the next C up would be 0.5 volts, then 1V, 2V, 4V, 8V for the following octaves. This system was used mainly by Yamaha and Korg.
`Joule Per Cubic Meter` (J/m³) is a unit in the category of Energy density. It is also known as joules per cubic meter, joule per cubic metre, joules per cubic metre, joule/cubic meter, joule/cubic metre. This unit is commonly used in the SI unit system. It has a dimension of ML⁻¹T⁻² where M is mass, L is length, and T is time. This unit is the standard SI unit in this category.
Joule Per Kelvin (J/K) is a unit in the category of Entropy. It is also known as joules per kelvin, joule/kelvin. This unit is commonly used in the SI unit system. Joule Per Kelvin (J/K) has a dimension of ML²T⁻²Q⁻¹ where M is mass, L is length, T is time, and Q is temperature. This unit is the standard SI unit in this category.
Joule Per Kilogram} (J/kg) is a unit in the category of Thermal heat capacity. It is also known as `joule/kilogram`, `joules per kilogram`. This unit is commonly used in the SI unit system. The unit has a dimension of L2T⁻² where L is length, and T is time. This unit is the standard SI unit in this category.
Specific heat capacity - The heat required to raise unit mass of a substance by unit temperature interval under specified conditions, such as constant pressure: usually measured in joules per kelvin per kilogram. Symbol c_p (for constant pressure) Also called specific heat.
The joule per mole (symbol: J· mol⁻¹) is an SI derived unit of energy per amount of material. Energy is measured in joules, and the amount of material is measured in moles. Physical quantities measured in J· mol⁻¹) usually describe quantities of energy transferred during phase transformations or chemical reactions. Division by the number of moles facilitates comparison between processes involving different quantities of material and between similar processes involving different types of materials. The meaning of such a quantity is always context-dependent and, particularly for chemical reactions, is dependent on the (possibly arbitrary) definition of a 'mole' for a particular process.
Energy needed to heat one mole of substance by 1 Kelvin, under standard conditions (not standard temperature and pressure STP). The standard molar entropy is usually given the symbol S, and has units of joules per mole kelvin ( J· mol⁻¹ K⁻¹). Unlike standard enthalpies of formation, the value of S is an absolute. That is, an element in its standard state has a nonzero value of S at room temperature.
`Joule Per Quartic Meter` (J/m⁴) is a unit for the spectral concentration of radiant energy density (in terms of wavelength), or the spectral radiant energy density (in terms of wave length). This unit is commonly used in the SI unit system.
Joule Per Square Meter (J/m²) is a unit in the category of Energy density. It is also known as joules per square meter, joule per square metre, joule/square meter, joule/square metre. This unit is commonly used in the SI unit system.
The magnetic moment of a magnet is a quantity that determines the force that the magnet can exert on electric currents and the torque that a magnetic field will exert on it. A loop of electric current, a bar magnet, an electron, a molecule, and a planet all have magnetic moments. The unit for magnetic moment is not a base unit in the International System of Units (SI) and it can be represented in more than one way. For example, in the current loop definition, the area is measured in square meters and I is measured in amperes, so the magnetic moment is measured in ampere-square meters (A m2). In the equation for torque on a moment, the torque is measured in joules and the magnetic field in tesla, so the moment is measured in Joules per Tesla (J u00b7T-1). These two representations are equivalent: 1 A u00b7m2 = 1 J u00b7T-1.
The joule-second is a unit equal to a joule multiplied by a second, used to measure action or angular momentum. The joule-second is the unit used for Planck's constant.
Thermal resistance is a heat property and a measure of a temperature difference by which an object or material resists a heat flow (heat per time unit or thermal resistance). Thermal resistance is the reciprocal thermal conductance. Absolute thermal resistance is the temperature difference across a structure when a unit of heat energy flows through it in unit time. It is the reciprocal of thermal conductance. The SI units of thermal resistance are kelvins per watt or the equivalent degrees Celsius per watt (the two are the same since as intervals).
In photometry, the lumen second is the SI derived unit of luminous energy. It is based on the lumen, the SI unit of luminous flux, and the second, the SI base unit of time. The lumen second is sometimes called the talbot (symbol T). An older name for the lumen second was the lumberg.
Metre per second is an SI derived unit of both speed (scalar) and velocity (vector quantity which specifies both magnitude and a specific direction), defined by distance in metres divided by time in seconds. The official SI symbolic abbreviation is mu00b7s-1, or equivalently either m/s.
The `meter per Square second` is the unit of acceleration in the International System of Units (SI). As a derived unit it is composed from the SI base units of length, the metre, and the standard unit of time, the second. Its symbol is written in several forms as m/s², or m s⁻². As acceleration, the unit is interpreted physically as change in velocity or speed per time interval, that is, `metre per second per second`.
Note that the physical dimension is the same as for Joule.
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Elucidation
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"Torque" is the tendency of a force to cause a rotation, is the product of the force and the distance from the center of rotation to the point where the force is applied. Torque has the same units as work or energy, but it is a different physical concept. To stress the difference, scientists measure torque in newton meters rather than in joules, the SI unit of work. One newton meter is approximately 0.737562 pound foot.
Newton Per Coulomb ( N/C) is a unit in the category of Electric field strength. It is also known as newtons/coulomb. Newton Per Coulomb ( N/C) has a dimension of MLT-3I-1 where M is mass, L is length, T is time, and I is electric current. It essentially the same as the corresponding standard SI unit V/m.
Newton Per Meter (N/m) is a unit in the category of Surface tension. It is also known as newtons per meter, newton per metre, newtons per metre, newton/meter, newton/metre. This unit is commonly used in the SI unit system. Newton Per Meter (N/m) has a dimension of MT-2 where M is mass, and T is time. This unit is the standard SI unit in this category.
The SI unit of pressure. The pascal is the standard pressure unit in the MKS metric system, equal to one newton per square meter or one "kilogram per meter per second per second." The unit is named for Blaise Pascal (1623-1662), French philosopher and mathematician, who was the first person to use a barometer to measure differences in altitude.
The SI unit of specific acoustic impedance. When sound waves pass through any physical substance the pressure of the waves causes the particles of the substance to move. The sound specific impedance is the ratio between the sound pressure and the particle velocity it produces. The specific impedance is 1 N · s · m⁻³ if unit pressure produces unit velocity.
unit of gravitational constant as product of the derived SI unit newton, the power of the SI base unit metre with the exponent 2 divided by the power of the SI base unit kilogram with the exponent 2
`Pascal Second Per Cubic Meter` (Pa-s/m³) is a unit in the category of Acoustic impedance. It is also known as `pascal-second/cubic meter`. It has a dimension of ML⁻⁴T⁻¹ where M is mass, L is length, and T is time. This unit is the standard SI unit in this category.
Pascal Second Per Meter (Pa-s/m) is a unit in the category of Specific acoustic impedance. It is also known as pascal-second/meter. Pascal Second Per Meter has a dimension of ML²T⁻¹ where M is mass, L is length, and T is time. It essentially the same as the corresponding standard SI unit kg/m2· s.
"Radian per Second" is the SI unit of rotational speed (angular velocity), and, also the unit of angular frequency. The radian per second is defined as the change in the orientation of an object, in radians, every second.
Angular acceleration is the rate of change of angular velocity. In SI units, it is measured in radians per Square second (rad/s²), and is usually denoted by the Greek letter α.
Square Meter Per Kilogram (m2/kg) is a unit in the category of Specific Area. It is also known as square meters per kilogram, square metre per kilogram, square metres per kilogram, square meter/kilogram, square metre/kilogram. This unit is commonly used in the SI unit system. Square Meter Per Kilogram (m2/kg) has a dimension of M-1L2 where M is mass, and L is length. This unit is the standard SI unit in this category.
Square Meter Per Mole (m2/mol) is a unit in the category of Specific Area. It is also known as square meters per mole, square metre per per, square metres per per, square meter/per, square metre/per. This unit is commonly used in the SI unit system. Square Meter Per Mole (m2/mol) has a dimension of M-1L2 where M is mass, and L is length. This unit is the standard SI unit in this category.
Square Metres per second is the SI derived unit of angular momentum, defined by distance or displacement in metres multiplied by distance again in metres and divided by time in seconds. The unit is written in symbols as m2/s or m2u00b7s-1 or m2s-1. It may be better understood when phrased as "metres per second times metres", i.e. the momentum of an object with respect to a position.
Volt Per Meter (V/m) is a unit in the category of Electric field strength. It is also known as volts per meter, volt/meter, volt/metre, volt per metre, volts per metre. This unit is commonly used in the SI unit system. Volt Per Meter (V/m) has a dimension of MLT⁻³I⁻¹ where M is mass, L is length, T is time, and I is electric current. This unit is the standard SI unit in this category.
'Volt per Second' is a unit of magnetic flux equaling one weber. This is the flux passing through a conducting loop and reduced to zero at a uniform rate in one second inducing an electric potential of one volt in the loop.
The divergence at a particular point in a vector field is (roughly) how much the vector field 'spreads out' from that point. Operationally, we take the partial derivative of each of the field with respect to each of its space variables and add all the derivatives together to get the divergence. Electric field (V/m) differentiated with respect to distance (m) yields V/(m²).
"Watt per Square Meter} is a unit of irradiance defined as the power received per area. This is a unit in the category of Energy flux. It is also known as watts per square meter, watt per square metre, watts per square metre, watt/square meter, watt/square metre. This unit is commonly used in the SI unit system. Watt Per Square Meter (W/m²) has a dimension of MT^{-3" where M is mass, and T is time. This unit is the standard SI unit in this category.
`Watt Per Square Meter Per Kelvin `(W m⁻² K⁻¹) is a unit in the category of Thermal heat transfer coefficient. It is also known as watt/square meter-kelvin. This unit is commonly used in the SI unit system. Watt Per Square Meter Per Kelvin (W m⁻² K⁻¹) has a dimension of MT⁻¹Q⁻¹ where M is mass, T is time, and Q is temperature. This unit is the standard SI unit in this category.
`Watt per steradian per square metre` is the SI unit of radiance (W·sr⁻¹·m⁻²), while that of spectral radiance in frequency is the watt per steradian per square metre per hertz (W·sr⁻¹·m⁻²·Hz⁻¹) and that of spectral radiance in wavelength is the watt per steradian per square metre, per metre (W·sr⁻¹·m⁻³), commonly the watt per steradian per square metre per nanometre (W·sr⁻¹·m⁻²·nm⁻¹). It has a dimension of ML⁻⁴T⁻³ where M is mass, L is length, and T is time. This unit is the standard SI unit in this category.
`Watt Per Steradian (W/sr)` is the unit in the category of Radiant intensity. It is also known as watts per steradian. This unit is commonly used in the SI unit system. Watt Per Steradian (W/sr) has a dimension of M· L⁻²· T⁻³ where M is mass, L is length, and T is time. This unit is the standard SI unit in this category.
The fact that there may be a finite granularity in the variations of the material basis (e.g. the smallest peak in a vynil that can be recognized by the piezo-electric transducer) does not prevent a data to be analog. It means only that the focus on such data encoding is on a scale that makes such variations negligible, making them practically a continuum.
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Elucidation
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Data that are decoded retaining its continuous variations characteristic.
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Example
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A vynil contain continuous information about the recorded sound.
'acoustical' refers to the perception mechanism of the observer that can occur through a microphone, a ear.
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Altlabel
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Sound
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Elucidation
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A 'Perceptual' which stands for a real world object whose spatiotemporal pattern makes it identifiable by an observer as a sound.
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Example
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When we use the term 'sound' what are we referring to? The EMMO identifis a sound as the physical object that can be heard by the observer (more exactly, by the sensor of the observer).
In this sense, a sound (which is an acoustical object) is to be identified as the air region that manifests the sound wave and is able to be perceived by an observer. In case the wave is travelling through water or steel, then these other media regions are the sounds.
If the waveform is travelling through a cable as electronic signal (analog or digital) it is no more a sound, since it cannot be perceived by an observer as an acoustical object. This electrical waveform (or digital packet) is another physical that may stand for a sound if interpreted by a device (e.g. an amplifier, a DA converter).
A data is a causal object whose variations (non-uniformity) can be recognised and eventually interpreted. A data can be of different physical types (e.g., matter, wave, atomic excited states). How the variations are recognised and eventually decoded depends on the interpreting rules that characterise that type of data. Variations are pure physical variations and do not necessarily possess semantic meaning.
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Comment
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The covering axiom that defines the data class discriminates within all the possible causal objects between encoded or non encoded.
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Altlabel
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Dedomena
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Altlabel
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Pattern
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Elucidation
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A perspective in which entities are represented according to the variation of their properties.
A discrete schema may be based on a continuum material basis that is filtered according to its variations. For example, a continuous voltage based signal can be considered 1 or 0 according to some threshold. Discrete does not mean that the material basis is discrete, but that the data are encoded according to such step-based rules.
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Elucidation
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Data whose variations are decoded according to a discrete schema.
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Example
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A text is a collection of discrete symbols. A compact disc is designed to host discrete states in the form of pits and lands.
Variations in data are generated by an agent (not necessarily human) and are intended to be decoded by the same or another agent using the same encoding rules. Data are always generated by an agent but not necessarily possess a semantic meaninig, either because it's lost or unknown or because simply they possess none (e.g. a random generation of symbols). A data object may be used as the physical basis for a sign, under Semiotics perspective.
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Comment
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We call "decoding" the act of recognise the variation according to a particular rule and generate another equivalent schema (e.g. in the agent's cognitive apparatus, as another form of data). We call "interpreting" the act of providing semantic meaning to data, which is covered by the semiotic perspective.
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Comment
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Data
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Altlabel
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EncodedVariation
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Elucidation
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A causal object whose properties variation are encoded by an agent and that can be decoded by another agent according to a specific rule.
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Example
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A Radio Morse Code transmission can be addressed by combination of perspectives. Physicalistic: the electromagnetic pulses can be defined as individual A (of type Field) and the strip of paper coming out a printer receiver can be defined as individual B (of type Matter). Data: both A and B are also DiscreteData class individuals. In particular they may belong to a MorseData class, subclass of DiscreteData. Perceptual: B is an individual belonging to the graphical entities expressing symbols. In particular is a formula under the MorseLanguage class, made of a combination of . and - symbols. Semiotics: A and B can be signs if they refers to something else (e.g. a report about a fact, names).
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Example
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A signal through a cable. A sound wave. Words on a page. The pattern of excited states within a computer RAM.
A 'graphical' aimed to represent a geometrical concept.
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Example
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A geometrical object can be expressed in many different forms.
For example, a line can be expressed by: a) an equation like y=mx+q, which is both an 'equation' and a 'geometrical' b) a line drawn with a pencil on a paper, which is simply a 'graphical' object c) a set of axioms, when the properties of a line are inferred by the interpreter reading them, that are both 'graphical' and also 'formula'
The case a) is a geometrical and mathematical, b) is geometrical and pictorial, while c) is geometrical and a composition of idiomatic strings.
This concept includes only things that are purposely created by an agent.
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Elucidation
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A 'Perceptual' which stands for a real world object whose spatial configuration is due to an explicit graphical procedure and shows an identifiable pattern.
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Example
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'Graphical' objects include writings, pictures, sketches ...
This is a really broad class that gathers all physical phenomena in which a variation occurs naturally, such as cloud patterns, tree rings, stains. It doesn't mean that such variations cannot be used to deduce something: in fact thaty can be seen as indexes (in semiotic sense) of a causally connected pehnomena. Simply, there is no agent behind that variation with the intention to transmit data.
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Altlabel
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EnvironmentalData
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Elucidation
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Data that occurs naturally without an encoding agent producing it.
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Example
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A cloud in the sky. The radiative spectrum of a star.
This class is the most general superclass for the categorization of contrasts that are perceivable through a specific human-related perception mechanism. This perspective is based on human characterization of perceptions. A 'Perceptual' can stand for another object in an EMMO described semiotic process (acting as sign or as object), just like a word on a paper (the perceptual object) may refer semiotically to another object. However, a perceptual is not necessarily a 'Sign' (e.g. a line sketched on a blackboard is a recognizable 'Perceptual' but it may stand for nothing). A 'Perceptual' becomes a semiotic object, when it is part of a 'Semiotic' process described by the ontologist within the EMMO, and it's done always specifying for which interpreter this relation occurs.
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Elucidation
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The class constrast individuals standing for entities that can stimulate a perception (e.g. a retina impression) to a human being and that are categorized accordingly to human perception mechanisms.
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Example
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A line scratched on a surface. A sound. A smell. The word 'cat' and the sound of the word 'cat' (the first one is graphical and the second acoustical).
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Example
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The meta-semiotic process: I see a cloud in the sky. Since I'm an EMMO ontologist, I create an individual named Cloud under the 'Perceptual' class, meaning that I recognize the cloud as an object thanks to a specific perceptual channel (e.g. through my eyes). This semiotic process occurs at meta-level: it's how I use the EMMO as tool for a direct representation of the world, understandable by others ontologists.
The semiotic process within EMMO: My friend looks at the same cloud and says: "It is an elephant". I use the EMMO to record this experience by declaring: - my friend as MyFriend individual, belonging to 'Interpreter' classes - the sound of the word "elephant" as an acoustical perception individual named ElephantWord, belonging to 'Perceptual' - a relation hasSign between Cloud and ElephantWord, that makes ElephantWord also belonging to 'Sign' class and Cloud belonging also to 'Object' class - a 'Semiosis' individual called MyFriendElephantCloud that hasParticipant: Cloud, ElephantWord and MyFriend, respectively as object, sign and interpreter.
So, the Perceptual class is here to categorized real-world objects at meta-level using common perceptual channels, for practical ontology usage.
We could have represented the word "elephant" within a physicalistic approach, by identifying it as a pressure wave in the air.
A 'Graphical' that stands for a real world object that shows a recognizable pictorial pattern without being necessarily associated to a symbolic language.
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Example
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A drawing of a cat. A circle on a paper sheet. The Mona Lisa.
Data that are expressed through quantum mechanical principles, and that can have several values / be in several states in the same place at the same time (quantum superposition), each of them with a certain probability.
A 'Perceptual' which stands for a real world object whose spatiotemporal pattern makes it identifiable by an observer through an optical perception employing the visible part of the electromagnetic spectrum.
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Example
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A cloud. A picture. A colour gradient on a wall. A stain. A mail.
The categorisation of computer languages is based on
Guide to the Software Engineering Body of Knowledge (SWEBOK(R)): Version 3.0, January 2014. Editors Pierre Bourque, Richard E. Fairley. Publisher: IEEE Computer Society PressWashingtonDCUnited States. ISBN:978-0-7695-5166-1. https://www.computer.org/education/bodies-of-knowledge/software-engineering
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Elucidation
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A formal language used to communicate with a computer.
IRIs are commonly used as identifiers for ontological entities, although the extended unicode character set is rarely used.
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Elucidation
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An Internationalized Resource Identifier (IRI) is a compact sequence of characters that identifies an abstract or physical resource. It is similar to URI, but greatly extends the allowed character set from ASCII to the Universal Character Set (Unicode/ISO 10646)..
An artificial computer language used to express information or knowledge, often for use in computer system design.
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Example
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Architecture description language – used as a language (or a conceptual model) to describe and represent system architectures.
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Example
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Hardware description language – used to model integrated circuits.
Architecture description language – used as a language (or a conceptual model) to describe and represent system architectures.
Algebraic Modeling Language which is a high-level programming languages for describing and solving high complexity problems like large-scale optimisation.
A program is a sequence of instructions understandable by a computer's central processing unit (CPU) that indicates which operations the computer should perform on a set of data.
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Altlabel
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Executable
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Elucidation
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A set of instructions that tell a computer what to do.
Software is usually used as a generic term for programs. However, in its broadest sense it can refer to all information (i.e., both programs and data) in electronic form and can provide a distinction from hardware, which refers to computers or other electronic systems on which software can exist and be use. Here we explicitly include in the definition also all the data (e.g. source code, script files) that takes part to the building of the executable, are necessary to the execution of a program or that document it for the users.
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Elucidation
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All or part of the programs, procedures, rules, and associated documentation of an information processing system.
A source code is the companion of an application, being it the entity used to generate the application list of CPU executable instructions.
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Comment
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Source code (also referred to as source or code) is the version of software as it is originally written (i.e., typed into a computer) by a human in plain text (i.e., human readable alphanumeric characters).
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Elucidation
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A programming language entity expressing a formal detailed plan of what a software is intended to do.
The term "Uniform Resource Locator" (URL) refers to the subset of URIs that, in addition to identifying a resource, provide a means of locating the resource by describing its primary access mechanism (e.g., its network "location").
The term "Uniform Resource Name" (URN) has been used historically to refer to both URIs under the "urn" scheme [RFC2141], which are required to remain globally unique and persistent even when the resource ceases to exist or becomes unavailable, and to any other URI with the properties of a name.
A task is a generic part of a workflow, without taking care of the task granularities. It means that you can declare that e.g. tightening a bolt is a task of building an airplane, without caring of the coarser tasks to which this tightening belongs.
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Altlabel
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Job
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Elucidation
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A procedure that is an hoilistic part of a workflow.
The definition of an arrangement implies that its spatial direct parts are not gained or lost during its temporal extension (they exist from the left to the right side of the time interval), so that the cardinality of spatial direct parts in an arrangement is constant. This does not mean that there cannot be a change in the internal structure of the arrangement direct parts. It means only that this change must not affect the existence of the direct part itself.
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Comment
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The use of spatial direct parthood in state definition means that an arrangement cannot overlap in space another arrangement that is direct part of the same whole.
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Altlabel
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MereologicalState
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Elucidation
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A causal object which is tessellated with only spatial direct parts.
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Example
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e.g. the existent in my glass is declared at t = t_start as made of two direct parts: the ice and the water. It will continue to exists as state as long as the ice is completely melt at t = t_end. The new state will be completely made of water. Between t_start and t_end there is an exchange of molecules between the ice and the water, but this does not affect the existence of the two states.
If we partition the existent in my glass as ice surrounded by several molecules (we do not use the object water as direct part) then the appearance of a molecule coming from the ice will cause a state to end and another state to begin.
'Existent' is the EMMO class to be used for representing real world physical objects under a reductionistic perspective (i.e. objects come from the composition of sub-part objects, both in time and space).
'Existent' class collects all individuals that stand for physical objects that can be structured in well defined temporal sub-parts called states, through the temporal direct parthood relation.
This class provides a first granularity hierarchy in time, and a way to axiomatize tessellation principles for a specific whole with a non-transitivity relation (direct parthood) that helps to retain the granularity levels.
e.g. a car, a supersaturated gas with nucleating nanoparticles, an atom that becomes ionized and then recombines with an electron.
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Comment
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An 'Existent' individual stands for a real world object for which the ontologist wants to provide univocal tessellation in time.
By definition, the tiles are represented by 'State'-s individual.
Tiles are related to the 'Existent' through temporal direct parthood, enforcing non-transitivity and inverse-functionality.
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Comment
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Being hasTemporalDirectPart a proper parthood relation, there cannot be 'Existent' made of a single 'State'.
Moreover, due to inverse functionality, a 'State' can be part of only one 'Existent', preventing overlapping between 'Existent'-s.
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Elucidation
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A 'Physical' which is a tessellation of 'State' temporal direct parts.
A granularity level is specified by a tiling decomposition of the whole y. A tiling is identified as a set of items {x1, x2, ... xn} called tiles that: - are proper parts of y - covers the entire whole (y = x1 +x2 + ... + xn) - do not overlap - are part of one, and one only, whole (inverse functional)
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Comment
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Direct parthood is the antitransitive parthood relation used to build the class hierarchy (and the granularity hierarchy) for this perspective.
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Elucidation
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A class devoted to categorize causal objects by specifying their granularity levels.
A causal object that is tessellated in direct parts.
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Conceptualisation
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A tessellation (or tiling) is the covering of a surface, often a plane, using one or more geometric shapes, called tiles, with no overlaps and no gaps.
This relation is not antitransitive, to enable partitioning of a causal structure with more than one tiling scheme (e.g. time and space partitioning).
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Comment
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This relation is a simple collector of all relations inverse functional direct parthoods that can be defined in specialised theories using reductionism.
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Elucidation
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The relation grouping all direct parthood relations used in the reductionistic perspective.
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Conceptualisation
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Direct parthood is the non transitive version of parthood enabling the establishment of hierarchy of granularities, starting with an entity and providing several tesselation levels according to specific criteria. The criteria are implemented in specialised versions of the direct parthood relation (e.g., metrological direct part, XML format direct part). The direct parts (tiles) and the tessellated entity (tessellation) are causally self connected (i.e., items), coherently with the concept behind the definition of the reductionistic perspective.
A relation between the whole and one of its tiles, where the tile is both spatially and temporally connected with the other tiles forming the tessellation.
In the EMMO we use the following JSON based syntax to represent arrays: - mono-dimensional array [v1,v2,...,vn] - bi-dimensional array [[v1,v2,...,vn],[w1,w2,...,2n]] This notation can be extended to multidimensional arrays.
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Conceptualisation
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An array is a datatype representing an ordered collection of elements (or values) that can be accessed by indexes. Arrays have an analog mathematical counterpart in vectors and matrixes, but are separate concepts. Arrays may be multidimensionals.
A string is made of concatenated symbols whose arrangement is one-dimensional. Each symbol can have only one previous and one next neighborhood (bidirectional list).
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Comment
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A string is not requested to respect any syntactic rule: it's simply directly made of symbols.
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Elucidation
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A physical made of more than one symbol sequentially arranged.
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Example
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The word "cat" considered as a collection of 'symbol'-s respecting the rules of english language.
In this example the 'symbolic' entity "cat" is not related to the real cat, but it is only a word (like it would be to an italian person that ignores the meaning of this english word).
If an 'interpreter' skilled in english language is involved in a 'semiotic' process with this word, that "cat" became also a 'sign' i.e. it became for the 'interpreter' a representation for a real cat.
Subclasses of 'Symbol' are alphabets, in formal languages terminology. A 'Symbol' is atomic for that alphabet, i.e. it has no parts that are symbols for the same alphabet. e.g. a math symbol is not made of other math symbols A Symbol may be a String in another language. e.g. "Bq" is the symbol for Becquerel units when dealing with metrology, or a string of "B" and "q" symbols when dealing with characters.
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Comment
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Symbols of a formal language need not be symbols of anything. For instance there are logical constants which do not refer to any idea, but rather serve as a form of punctuation in the language (e.g. parentheses).
Symbols of a formal language must be capable of being specified without any reference to any interpretation of them. (Wikipedia)
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Comment
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The class is the idea of the symbol, while the individual of that class stands for a specific mark (or token) of that idea.
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Altlabel
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AlphabeticEntity
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Elucidation
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The class of individuals that stand for an elementary mark of a specific symbolic code (alphabet).
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Example
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The class of letter "A" is the symbol as idea and the letter A that you see on the screen is the mark that can be represented by an individual belonging to "A".
A symbolic entity is not necessarily graphical (e.g. it doesn't necessarily have the physical shape of a letter), but its elements can be decoded and put in relation with an alphabet. In other words, a sequence of bit "1000010" in a RAM (a non-graphical entity) is a valid symbol since it can be decoded through ASCII rules as the letter "B". The same holds for an entity standing for the sound of a voice saying: "Hello", since it can be decomposed in discrete parts, each of them being associated to a letter of an alphabet.
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Comment
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A symbolic object possesses a reductionistic oriented structure. For example, text is made of words, spaces and punctuations. Words are made of characters (i.e. atomic symbols).
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Elucidation
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A discrete data whose elements can be decoded as tokens from one or more alphabets, without necessarily respecting syntactic rules.
This class collects individuals that represents arrangements of strings, or other symbolic compositions, without any particular predifined arrangement schema.
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Elucidation
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A symbolic entity made of other symbolic entities according to a specific spatial configuration.
The class for entities which stands for data expressed using a symbolic encoding.
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Conceptualisation
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A symbolic data is a a data that is rooted on some symbolic based encoding, such as floating point numbers, strings, integer. They are not to be intended as mathematical entities (even if they may be interpreted as such) but as syntactic structures (datastructures or datatypes) based on concatenated tokens (or symbols, letters) that can deliver data.
This is the superproperty of all data properties used to serialise a fundamental data type in the EMMO Data perspective. An entity can have only one data value expressing its serialisation (e.g. a Real entity cannot have two different real values).
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Elucidation
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The owl:dataProperty that provides a serialisation of an EMMO data entity.
Number dN of spontaneous nuclear transitions or nuclear disintegrations for a radionuclide of amount N produced during a short time interval dt, divided by this time interval.
Sum of the kinetic energy of the α-particle produced in the disintegration process and the recoil energy of the product atom in a reference frame in which the emitting nucleus is at rest before its disintegration.
"In the name “amount of substance”, the word “substance” will typically be replaced by words to specify the substance concerned in any particular application, for example “amount of hydrogen chloride, HCl”, or “amount of benzene, C6H6 ”. It is important to give a precise definition of the entity involved (as emphasized in the definition of the mole); this should preferably be done by specifying the molecular chemical formula of the material involved. Although the word “amount” has a more general dictionary definition, the abbreviation of the full name “amount of substance” to “amount” may be used for brevity."
Axial vector quantity describing the rotation around an axis, with magnitude ω=|dφ/dt|, where dφ is the plane angle change during the infinitesimal time interval with duration dt, and with direction along the axis for which the rotation is clockwise.
Since the nucleus account for nearly all of the total mass of atoms (with the electrons and nuclear binding energy making minor contributions), the atomic mass measured in Da has nearly the same value as the mass number.
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Comment
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The atomic mass is often expressed as an average of the commonly found isotopes.
Sum of the maximum beta-particle kinetic energy and the recoil energy of the atom produced in a reference frame in which the emitting nucleus is at rest before its disintegration.
Temperature is a relative quantity that can be used to express temperature differences. Unlike ThermodynamicTemperature, it cannot express absolute temperatures.
In non-relativistic physics, the centre of mass doesn’t depend on the chosen reference frame.
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Elucidation
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The unique point where the weighted relative position of the distributed mass of an Item sums to zero. Equivalently, it is the point where if a force is applied to the Item, causes the Item to move in direction of force without rotation.
Dimensionless scalar value which describes the ratio of the force of friction between two bodies and the force pressing them together; depends on the materials used, ranges from near zero to greater than one.
At a point on the surface separating two media with different thermodynamic temperatures, magnitude of the density of heat flow rate φ divided by the absolute value of temperature difference ΔT.
Coercive field strength in a substance when either the magnetic flux density or the magnetic polarization and magnetization is brought from its value at magnetic saturation to zero by monotonic reduction of the applied magnetic field strength.
Quotient of the product of the electric charge of a particle and the magnitude of the magnetic flux density of the magnetic field, and the particle mass.
At a fixed point in a medium, the direction of propagation of heat is opposite to the temperature gradient. At a point on the surface separating two media with different temperatures, the direction of propagation of heat is normal to the surface, from higher to lower temperatures.
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Altlabel
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AreicHeatFlowRate
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Elucidation
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Vector quantity with magnitude equal to the heat flow rate dΦ through a surface element divided by the area dA of the element, and direction eφ in the direction of propagation of heat.
quotient of the number of vibrational modes in an infinitesimal interval of angular frequency, and the product of the width of that interval and volume
Partial differential quotient of the cross section of a process with respect to the solid angle around a given direction and the energy of a particle scattered in that direction.
The mass that it seems to have when responding to forces, or the mass that it seems to have when interacting with other identical particles in a thermal distribution.
An electric dipole, vector quantity of magnitude equal to the product of the positive charge and the distance between the charges and directed from the negative charge to the positive charge.
Vector quantity obtained at a given point by adding the electric polarization P to the product of the electric field strength E and the electric constant ε0.
A property of an electrical conductor by which a change in current through it induces an electromotive force in both the conductor itself and in any nearby conductors by mutual inductance.
At a given point within a domain of quasi-infinitesimal volume V, vector quantity equal to the electric dipole moment p of the substance contained within the domain divided by the volume V.
In an infinite medium, the ratio of the mean number of neutrons produced by fission due to neutrons of all energies to the mean number of neutrons produced by fissions due to thermal neutrons only.
in a metal, highest occupied energy level at zero thermodynamic temperature, where energy level means the energy of an electron in the interior of a substance
Describes the effect that changing the volume of a crystal lattice has on its vibrational properties, and, as a consequence, the effect that changing temperature has on the size or dynamics of the lattice.
Examples of condition might be constant volume or constant pressure for a gas.
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Elucidation
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Quantity C = dQ/dT, when the thermodynamic temperature of a system is increased by dT as a result of the addition of a amount of heat dQ, under given condition.
Quantum number of an atom describing the inclination of the nuclear spin with respect to a quantization axis given by the magnetic field produced by the orbital electrons.
The frequency standard in the SI system in which the photon absorption by transitions between the two hyperfine ground states of caesium-133 atoms are used to control the output frequency.
Quotient of the number of internal conversion electrons and the number of gamma quanta emitted by the radioactive atom in a given transition, where a conversion electron represents an orbital electron emitted through the radioactive decay.
A state quantity equal to the difference between the total energy of a system and the sum of the macroscopic kinetic and potential energies of the system.
Normally a standard solution is a solution of the ion at a molality of 1 mol/kg (exactly). Standardized conditions are normally 1013,25 hPa and 25 °C.
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Comment
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The correction factor is called activity coefficient and it is determined experimentally. See ActivityCoefficient
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Elucidation
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ratio of the product of ion molality b and a correction factor γ to the molality b° of the same ion in a standard solution under standardized conditions: a = bγ / b°.
Difference between energy of an electron at rest at infinity and a certain energy level which is the energy of an electron in the interior of a substance.
Differential quotient of q with respect to l, where q is the average total charge of all positive ions produced by an ionizing charged particle over a path l, divided by the elementary charge.
Fraction of atoms in an Ising ferromagnet having magnetic moments in one direction, minus the fraction having magnetic moments in the opposite direction.
The luminous efficacy of monochromatic radiation of frequency 540 × 10 12 Hz, K cd , is a technical constant that gives an exact numerical relationship between the purely physical characteristics of the radiant power stimulating the human eye (W) and its photobiological response defined by the luminous flux due to the spectral responsivity of a standard observer (lm) at a frequency of 540 × 10 12 hertz.
A measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle. It is based on the luminosity function, which is a standardized model of the sensitivity of the human eye.
For an atom or nucleus, this energy is quantized and can be written as:
W = g μ M B
where g is the appropriate g factor, μ is mostly the Bohr magneton or nuclear magneton, M is magnetic quantum number, and B is magnitude of the magnetic flux density.
-- ISO 80000
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Elucidation
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Vector quantity μ causing a change to its energy ΔW in an external magnetic field of field flux density B:
A vector quantity equal to the product of the current, the loop area, and the unit vector normal to the loop plane, the direction of which corresponds to the loop orientation
Scalar or tensor quantity the product of which by the magnetic constant μ0 and by the magnetic field strength H is equal to the magnetic polarization J.
At a given point within a domain of quasi-infinitesimal volume V, vector quantity equal to the magnetic area moment m of the substance contained within the domain divided by the volume V.
For ionizing uncharged particles of a given type and energy, the differential quotient of Rtr with respect to l. Where Rtr is the mean energy that is transferred to kinetic energy of charged particles by interactions of the uncharged particles of incident radiant energy R in traversing a distance l in the material of density rho, divided by rho and R
The mean free path may thus be specified either for all interactions, i.e. total mean free path, or for particular types of interaction such as scattering, capture, or ionization.
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in a given medium, average distance that particles of a specified type travel between successive interactions of a specified type.
Mean total rectified path length travelled by a particle in the course of slowing down to rest in a given material averaged over a group of particles having the same initial energy.
Equivalent to the Boltzmann constant, but expressed in units of energy per temperature increment per mole (rather than energy per temperature increment per particle).
Quotient of the total number of fission or fission-dependent neutrons produced in the duration of a time interval and the total number of neutrons lost by absorption and leakage in that duration.
Given an electric current in a thin conducting loop and the linked flux caused by that electric current in another loop, the mutual inductance of the two loops is the linked flux divided by the electric current.
For a two-terminal element or a two-terminal circuit under periodic conditions, quantity equal to the square root of the difference of the squares of the apparent power S and the active power P.
Using direct parthood EMMO creates a well-defined broadcasting between granularity levels. This also make it possible to count the direct parts of each granularity level.
At about 25 °C aqueous solutions with: pH < 7 are acidic; pH = 7 are neutral; pH > 7 are alkaline. At temperatures far from 25 °C the pH of a neutral solution differs significantly from 7.
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Comment
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Written as pH
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Number quantifying the acidic or the alkaline character of a solution, equal to the negative of the decimal logarithm of ion activity aH+ of the hydrogen cation H+ pH = −10 log(a_H+).
number quantifying the acidic or the alkaline character of a solution, equal to the negative of the decimal logarithm of ion activity aOH- of the hydroxide anion OH- pH = −10 log(a_OH-)
Differential quotient of N with respect to time, where N is the number of particles being emitted from an infinitesimally small volume element in the time interval of duration dt, and dt.
Under sinusoidal conditions, phase difference between the voltage applied to a linear two-terminal element or two-terminal circuit and the electric current in the element or circuit.
According to the SI brochure counting does not automatically qualify a quantity as an amount of substance.
This quantity is used only to describe the outcome of a counting process, without regard of the type of entities.
There are also some quantities that cannot be described in terms of the seven base quantities of the SI, but have the nature of a count. Examples are a number of molecules, a number of cellular or biomolecular entities (for example copies of a particular nucleic acid sequence), or degeneracy in quantum mechanics. Counting quantities are also quantities with the associated unit one.
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A pure number, typically the number of something.
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1, i, π, the number of protons in the nucleus of an atom
Quantities defined as ratios `Q=A/B` having equal dimensions in numerator and denominator are dimensionless quantities but still have a physical dimension defined as dim(A)/dim(B).
Johansson, Ingvar (2010). "Metrological thinking needs the notions of parametric quantities, units and dimensions". Metrologia. 47 (3): 219–230. doi:10.1088/0026-1394/47/3/012. ISSN 0026-1394.
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The class of quantities that are the ratio of two quantities with the same physical dimensionality.
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Example
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refractive index, volume fraction, fine structure constant
In a nuclear reaction, sum of the kinetic energies and photon energies of the reaction products minus the sum of the kinetic and photon energies of the reactants.
In an infinite medium, the probability that a neutron slowing down will traverse all or some specified portion of the range of resonance energies without being absorbed.
The Rydberg constant represents the limiting value of the highest wavenumber (the inverse wavelength) of any photon that can be emitted from the hydrogen atom, or, alternatively, the wavenumber of the lowest-energy photon capable of ionizing the hydrogen atom from its ground state.
Physical constant that by definition (after the latest revision of the SI system that was enforsed May 2019) has a known exact numerical value when expressed in SI units.
fraction of nearest-neighbour atom pairs in an Ising ferromagnet having magnetic moments in one direction, minus the fraction having magnetic moments in the opposite direction
In an infinite homogenous medium, one-sixth of the mean square of the distance between the neutron source and the point where a neutron reaches a given energy.
Measure of a conical geometric figure, called solid angle, formed by all rays, originating from a common point, called the vertex of the solid angle, and passing through the points of a closed, non-self-intersecting curve in space considered as the border of a surface.
The solubility may be expressed as a concentration, molality, mole fraction, mole ratio, etc.
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The analytical composition of a saturated solution, expressed in terms of the proportion of a designated solute in a designated solvent, is the solubility of that solute.
For the dissociation of a salt AmBn → mA + nB, the solubility product is KSP = am(A) ⋅ an(B), where a is ionic activity and m and n are the stoichiometric numbers.
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Altlabel
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SolubilityProductConstant
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product of the ion activities of the ions resulting from the dissociation of a solute in a saturated solution, raised to powers equal to their stoichiometric numbers.
Coefficient of heat transfer when heat exchange takes place between a body at thermodynamic temperature Ts and its surroundings that are at a reference temperature Tr.
at a given point on a two-dimensional domain of quasi-infinitesimal area dA, scalar quantity equal to the mass dm within the domain divided by the area dA, thus ρA = dm/dA.
In an anisotropic medium, thermal conductivity is a tensor quantity.
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At a point fixed in a medium with a temperature field, scalar quantity λ characterizing the ability of the medium to transmit heat through a surface element containing that point: φ = −λ grad T, where φ is the density of heat flow rate and T is thermodynamic temperature.
In an infinite medium, the quotient of the number of thermal neutrons absorbed in a fissionable nuclide or in a nuclear fuel, as specified, and the total number of thermal neutrons absorbed.
Thermodynamic temperature is the absolute measure of temperature. It is defined by the third law of thermodynamics in which the theoretically lowest temperature is the null or zero point.
Time can be seen as the duration of an event or, more operationally, as "what clocks read".
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The indefinite continued progress of existence and events that occur in apparently irreversible succession from the past through the present to the future.
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Definition
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One-dimensional subspace of space-time, which is locally orthogonal to space.
Even though torque has the same physical dimension as energy, it is not of the same kind and can not be measured with energy units like joule or electron volt.
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Elucidation
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The effectiveness of a force to produce rotation about an axis, measured by the product of the force and the perpendicular distance from the line of action of the force to the axis.
Sum of all cross sections corresponding to the various reactions or processes between an incident particle of specified type and energy and a target entity.
Quotient of the total mean charge of all positive ions produced by an ionizing charged particle along its entire path and along the paths of any secondary charged particles, and the elementary charge.
For charged particles of a given type and energy E0 the differential quotient of E with respect to x, where E is the mean energy lost by the charged particles in traversing a distance x in the given material.
The velocity depends on the choice of the reference frame. Proper transformation between frames must be used: Galilean for non-relativistic description, Lorentzian for relativistic description.
-- IEC, note 2
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Comment
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The velocity is related to a point described by its position vector. The point may localize a particle, or be attached to any other object such as a body or a wave.
-- IEC, note 1
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Definition
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Vector quantity giving the rate of change of a position vector.
Quantity equal to the volume dV of substance crossing a given surface during a time interval with infinitesimal duration dt, divided by this duration, thus qV = dV / dt-
A chemical substance composed of many identical molecules (or molecular entities) composed of atoms from more than one element held together by chemical bonds.
The IUPAC Gold Book defines the a chemical element both as: - a species of atoms; all atoms with the same number of protons in the atomic nucleus - a pure chemical substance composed of atoms with the same number of protons in the atomic nucleus
This qualifies a chemical element as a name and not a matter obejct that can stand for an atom or a substance.
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The symbol for a specific chemical element, that can stand both for an atom or a substance.
A chemical entity comprises the two different ways to represents matter: as single recognizable particle entity (molecular entity) and as a composition of particle entities (substance).
This distinction is not well assessed in actual chemical nomenclature, in which an element name refers to both the pure elemental substance or the atom.
In the EMMO we force the adoption of a more strict categorization based on mereotopology.
The class Material hosts the subclasses for which a substance can be identified without necessarily considering its nature of molecule/atom or substance (e.g. hydrocarbon is the class of both hydrocarbon molecules or gases).
A chemical formula may also include other symbols such as parentheses, plus and minus signs, brackets
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A symbolic construct that provides informations about the chemical proportions of the elements that constitute a chemical compound or a specific molecule.
An expression that provides information about the element types that constiture a molecule or a molecular substance and their number, together with simple information about the connectivity of its groups by using parenthesis or by goruping element names according to its molecular structure.
This concept includes only things that are purposely created by an agent.
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A 'Perceptual' which stands for a real world object whose spatial configuration is due to an explicit graphical procedure and shows an identifiable pattern.
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Example
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'Graphical' objects include writings, pictures, sketches ...
The International Chemical Identifier (InChI) textual identifier proposed by IUPAC to provide a standard encoding for databases of molecular information.
OpenSMILES is an open specification of the SMILE language for specifying molecular structures, which has become a defacto standard for exchange of molecular structures.
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OpenSMILE representation of a molecular structure.
A computational application that uses existing data to predict the behaviour of a system without providing a identifiable analogy with the original object.
A computational application that uses an empiric equation to predict the behaviour of a system without relying on the knowledge of the actual physical phenomena occurring in the object.
A material_relation can e.g. return a predefined number, return a database query, be an equation that depends on other physics_quantities.
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An 'equation' that stands for a physical assumption specific to a material, and provides an expression for a 'physics_quantity' (the dependent variable) as function of other variables, physics_quantity or data (independent variables).
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The Lennard-Jones potential. A force field. An Hamiltonian.
A mathematical model can be defined as a description of a system using mathematical concepts and language to facilitate proper explanation of a system or to study the effects of different components and to make predictions on patterns of behaviour.
Abramowitz and Stegun, 1968
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An analogical icon expressed in mathematical language.
A physics-based model based on a physics equation describing the behaviour of mesoscopic entities, i.e. a set of bounded atoms like a molecule, bead or nanoparticle.
A computational application that uses a physical model to predict the behaviour of a system, providing a identifiable analogy with the original object.
While every 'process' in the EMMO involves physical objects, this class is devoted to represent real world objects that express a phenomenon relevant for the ontologist
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A 'process' that is recognized by physical sciences and is categorized accordingly.
This must be a mathematical function v(t), x(t). A dataset as solution is a conventional sign.
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Elucidation
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A function solution of a physics equation that provides a methods for the prediction of some quantitiative properties of an object.
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Example
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A parabolic function is a prediction of the trajectory of a falling object in a gravitational field. While it has predictive capabilities it lacks of an analogical character, since it does not show the law behind that trajectory.
The equation that describes the velocity of a uniform accelerated body v = v0 + a*t is a functional icon. In general every analitical solution of a mathematical model can be considered an icon. A functional icon expresses its similarity with the object when is part of a process the makes it imitate the behavior of the object. In the case of v = v0 + a*t, plotting the velocity over time or listing their values at certain instants is when the icon expresses it functionality.
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Elucidation
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A functional icon that imitates the behaviour of the object through mathematical evaluations of some mathematical construct.
An icon that not only resembles the object, but also can express some of the object's functions.
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Example
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A small scale replica of a plane tested in a wind gallery shares the same functionality in terms of aerodynamic behaviour of the bigger one.
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Example
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Pinocchio is a functional icon of a boy since it imitates the external behaviour without having the internal biological structure of a human being (it is made of magic wood...).
An application aimed to functionally reproduce an object.
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Example
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An application that predicts the pressure drop of a fluid in a pipe segment is aimed to functionally reproduce the outcome of a measurement of pressure before and after the segment.
The 'theory' is e.g. a proposition, a book or a paper whose sub-symbols suggest in the mind of the interpreter an interpretant structure that can represent a 'physical'.
It is not an 'icon' (like a math equation), because it has no common resemblance or logical structure with the 'physical'.
A simulation in which more than one model are solved together with a coupled method.
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Example
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Solving within the same linear system the discretised form of the pressure and momentum equation for a fluid, using the ideal gas law as material relation for connecting pressure to density.
`Ampere hour` is a practical unit of electric charge equal to the charge flowing in one hour through a conductor passing one ampere. An ampere-hour or amp-hour (symbol Ah, AHr, A · h, A h) is a unit of electric charge, with sub-units milliampere-hour (mAh) and milliampere second (mAs). One ampere-hour is equal to 3600 coulombs (ampere-seconds), the electric charge transferred by a steady current of one ampere for one hour. The ampere-hour is frequently used in measurements of electrochemical systems such as electroplating and electrical batteries. The commonly seen milliampere-hour (mAh or mA · h) is one-thousandth of an ampere-hour (3.6 coulombs).
A measure used to express how a current is subject to temperature. Originally used in Wien's Law to describe phenomena related to filaments. One use today is to express how a current generator derates with temperature.
An astronomical unit (abbreviated as AU, au, a.u., or ua) is a unit of length equal to 149,597,870,700 metres (92,955,807.273 mi) or approximately the mean Earth Sun distance. The symbol ua is recommended by the International Bureau of Weights and Measures, and the international standard ISO 80000, while au is recommended by the International Astronomical Union, and is more common in Anglosphere countries. In general, the International System of Units only uses capital letters for the symbols of units which are named after individual scientists, while au or a.u. can also mean atomic unit or even arbitrary unit. However, the use of AU to refer to the astronomical unit is widespread. The astronomical constant whose value is one astronomical unit is referred to as unit distance and is given the symbol A. [Wikipedia]
Cubic Meter Per Hour (m3/h) is a unit in the category of Volume flow rate. It is also known as cubic meters per hour, cubic metre per hour, cubic metres per hour, cubic meter/hour, cubic metre/hour, cubic meter/hr, cubic metre/hr, flowrate. Cubic Meter Per Hour (m3/h) has a dimension of L3T-1 where L is length, and T is time. It can be converted to the corresponding standard SI unit m3/s by multiplying its value by a factor of 0.00027777777.
The unified atomic mass unit (symbol: μ) or dalton (symbol: Da) is a unit that is used for indicating mass on an atomic or molecular scale. It is defined as one twelfth of the rest mass of an unbound atom of carbon-12 in its nuclear and electronic ground state, and has a value of 1.660538782(83) × 10⁻²⁷ kg. One Da is approximately equal to the mass of one proton or one neutron. The CIPM have categorised it as a "non-SI unit whose values in SI units must be obtained experimentally".
A degree (in full, a degree of arc, arc degree, or arcdegree), usually denoted by ° (the degree symbol), is a measurement of plane angle, representing 1/360 of a full rotation; one degree is equivalent to 2π /360 rad, 0.017453 rad. It is not an SI unit, as the SI unit for angles is radian, but is an accepted SI unit.
Derived unit for the product of the temperature in degrees Celsius and the mass density of a medium, integrated over vertical depth or height in metres.
A unit of measure for the rate of change of plane angle, dω / dt, in durations of one minute.The vector ω is directed along the axis of rotation in the direction for which the rotation is clockwise.
An electron volt (eV) is the energy that an electron gains when it travels through a potential of one volt. You can imagine that the electron starts at the negative plate of a parallel plate capacitor and accelerates to the positive plate, which is at one volt higher potential. Numerically 1 eV approximates 1.6x10⁻¹⁹ joules, where 1 joule is 6.2x10¹⁸ eV. For example, it would take 6.2x10²⁰ eV/sec to light a 100 watt light bulb.
The customary metric unit of land area, equal to 100 ares. One hectare is a square hectometer, that is, the area of a square 100 meters on each side: exactly 10 000 square meters or approximately 107 639.1 square feet, 11 959.9 square yards, or 2.471 054 acres.
The hour (common symbol: h or hr) is a unit of measurement of time. In modern usage, an hour comprises 60 minutes, or 3,600 seconds. It is approximately 1/24 of a mean solar day. An hour in the Universal Coordinated Time (UTC) time standard can include a negative or positive leap second, and may therefore have a duration of 3,599 or 3,601 seconds for adjustment purposes. Although it is not a standard defined by the International System of Units, the hour is a unit accepted for use with SI, represented by the symbol h.
The litre (American spelling: `liter`; SI symbol l or L) is a non-SI metric system unit of volume equal to 1 `cubic decimetre` (dm³), 1,000 cubic centimetres (cm³) or 1/1000 `cubic metre`. If the lower case "L" is used as the symbol, it is sometimes rendered as a cursive "l" to help distinguish it from the capital "I", although this usage has no official approval by any international bureau.
-- QUDT
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Definition
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A non-SI unit of volume defined as 1 cubic decimetre (dm3),
The SI unit for measuring the illumination (illuminance) of a surface. One lux is defined as an illumination of one lumen per square meter or 0.0001 phot. In considering the various light units, it's useful to think about light originating at a point and shining upon a surface. The intensity of the light source is measured in candelas; the total light flux in transit is measured in lumens (1 lumen = 1 candelau00b7steradian); and the amount of light received per unit of surface area is measured in lux (1 lux = 1 lumen/square meter). One lux is equal to approximately 0.09290 foot candle.
Metre per hour is a metric unit of both speed (scalar) and velocity (Vector (geometry)). Its symbol is m/h or mu00b7h-1 (not to be confused with the imperial unit symbol mph. By definition, an object travelling at a speed of 1 m/h for an hour would move 1 metre.
Meter Per Minute (m/min) is a unit in the category of Velocity. It is also known as meter/minute, meters per minute, metre per minute, metres per minute. Meter Per Minute (m/min) has a dimension of LT-1 where L is length, and T is time. It can be converted to the corresponding standard SI unit m/s by multiplying its value by a factor of 0.016666666666
A minute is a unit of measurement of time. The minute is a unit of time equal to 1/60 (the first sexagesimal fraction of an hour or 60 seconds. In the UTC time scale, a minute on rare occasions has 59 or 61 seconds; see leap second. The minute is not an SI unit; however, it is accepted for use with SI units. The SI symbol for minute or minutes is min (for time measurement) or the prime symbol after a number, e.g. 5' (for angle measurement, even if it is informally used for time).
The neper is a logarithmic unit for ratios of measurements of physical field and power quantities, such as gain and loss of electronic signals. It has the unit symbol Np. The unit's name is derived from the name of John Napier, the inventor of logarithms. As is the case for the decibel and bel, the neper is not a unit in the International System of Units (SI), but it is accepted for use alongside the SI. Like the decibel, the neper is a unit in a logarithmic scale. While the bel uses the decadic (base-10) logarithm to compute ratios, the neper uses the natural logarithm, based on Euler's number
Unit of measurement for quantities of type level or level difference, which are defined as the natural logarithm of the ratio of power- or field-type quantities.
The value of a ratio in nepers is given by `ln(x1/x2)` where `x1` and `x2` are the values of interest (amplitudes), and ln is the natural logarithm. When the values are quadratic in the amplitude (e.g. power), they are first linearised by taking the square root before the logarithm is taken, or equivalently the result is halved.
Radian Per Minute (rad/min) is a unit in the category of Angular velocity. It is also known as radians per minute, radian/minute. Radian Per Minute (rad/min) has a dimension of aT-1 where T is time. It can be converted to the corresponding standard SI unit rad/s by multiplying its value by a factor of 0.0166666666667.
This is a list of units that are not defined as part of the International System of Units (SI), but are otherwise mentioned in the SI brouchure, because either the General Conference on Weights and Measures (CGPM) accepts their use as being multiples or submultiples of SI-units, they have important contemporary application worldwide, or are otherwise commonly encountered worldwide.
A square degree is a non-SI unit measure of solid angle. It is denoted in various ways, including deg, sq. deg. and °². Just as degrees are used to measure parts of a circle, square degrees are used to measure parts of a sphere. Analogous to one degree being equal to π /180 radians, a square degree is equal to (π /180) or about 1/3283 steradian. The number of square degrees in a whole sphere is or approximately 41 253 deg. This is the total area of the 88 constellations in the list of constellations by area. For example, observed from the surface of the Earth, the Moon has a diameter of approximately 0.5°, so it covers a solid angle of approximately 0.196 deg, which is 4.8 × 10 of the total sky sphere.
An 'atom' is a 'nucleus' surrounded by an 'electron_cloud', i.e. a quantum system made of one or more bounded electrons.
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ChemicalElement
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A standalone atom has direct part one 'nucleus' and one 'electron_cloud'.
An O 'atom' within an O₂ 'molecule' is an 'e-bonded_atom'.
In this material branch, H atom is a particular case, with respect to higher atomic number atoms, since as soon as it shares its electron it has no nucleus entangled electron cloud.
We cannot say that H₂ molecule has direct part two H atoms, but has direct part two H nucleus.
"... in the 'classical' picture ordinary matter is made of atoms, in which electrons are held in orbit around a nucleus of protons and neutrons by the electrical attraction of opposite charges. We can now give this model a more sophisticated formulation by attributing the binding force to the exchange of photons between the electrons and the protons in the nucleus. However, for the purposes of atomic physics this is overkill, for in this context quantization of the electromagnetic field produces only minute effects (notably the Lamb shift and the anomalous magnetic moment of the electron). To excellent approximation we can pretend that the forces are given by Coulomb's law (together with various magnetic dipole couplings). The point is that in a bound state enormous numbers of photons are continually streaming back and forth, so that the "lumpiness" of the field is effectively smoothed out, and classical electrodynamics is a suitable approximation to the truth. But in most elementary particle processes, such as the photoelectric effect or Compton scattering, individual photons are involved, and quantization can no longer be ignored." D. Griffiths, "Introduction to elementary Particles", Wiley-VCH, 2004, pp.16-17
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Conceptualisation
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A bonded object is a sequence of fundamental interactions that can be described approximatively by Schrodinger formulation. A bonded object is typically characterised by having quantum states (e.g. electron states in an atom, energy levels of a molecule). Furthermore, a bonded object is made of elementary particles that travels from the beginning to the end of the entity (i.e. a bonded object doesn't change its components).
A composite particle is a bonded particle for which it is possible to clearly define its bosonic or fermionic behaviour. The term particle is then reserved for entities whose fermionic or bosonic nature is clearly defined.
Examples of composite particles with integer spin: spin 0: H1 and He4 in ground state, pion spin 1: H1 and He4 in first excited state, meson spin 2: O15 in ground state.
Examples of composite particles with half-integer spin: spin 1/2: He3 in ground state, proton, neutron spin 3/2: He5 in ground state, Delta baryons (excitations of the proton and neutron)
The class of physical objects possessing a structure that is larger than a single composite particle, for which its bosonic or fermionic nature is undetermined.
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Conceptualisation
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A composite physical object is made of bonded objects (i.e. characterised by their quantum states using a Schrodinger equation approach) that are connected together by elementary particles travelling between them. These elemenentary particles are real particles, describing the existance of a classical field (e.g. Coulomb potential between charged particles).
A matter entity requires the presence of fermions without excluding the presence of real or virtual fundamental bosons parts that are responsible for the interactions between the (real) fundamental fermions.
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Comment
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Matter includes ordinary- and anti-matter. It is possible to have entities that are made of particle and anti-particles (e.g. mesons made of a quark and an anti-quark pair) so that it is possible to have entities that are somewhat heterogeneous with regards to this distinction.
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PhysicalSubstance
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Elucidation
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The class of physical objects that have some fermionic quantum parts.
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Conceptualisation
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The interpretation of the term "matter" is not univocal. Several concepts are labelled with this term, depending on the field of science. The concept mass is sometimes related to the term "matter", even if the former refers to a physical quantity (precisely defined by modern physics) while the latter is a type that qualifies a physical entity. It is possible to identify more than one concept that can be reasonably labelled with the term "matter". For example, it is possible to label as matter only the entities that are made up of atoms. Or more generally, we can be more fine-grained and call "matter" the entities that are made up of protons, neutrons or electrons, so that we can call matter also a neutron radiation or a cathode ray. A more fundamental approach, that we embrace for the EMMO, considers matter as entities that are made of fermions (i.e. quarks and leptons) requiring their presence, without excluding particles like the W and Z bosons that possess some mass, but are not fermions. Antimatter is a subclass of matter.
Molecular entity is used as a general term for singular entities, irrespective of their nature, while chemical species stands for sets or ensembles of molecular entities. Note that the name of a compound may refer to the respective molecular entity or to the chemical species,
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Comment
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This concept is strictly related to chemistry. For this reason an atom can be considered the smallest entity that can be considered "molecular", including nucleus when they are seen as ions (e.g. H⁺, He⁺⁺).
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Comment
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Molecular entity is used as a general term for singular entities, irrespective of their nature, while chemical species stands for sets or ensembles of molecular entities.
Note that the name of a compound may refer to the respective molecular entity or to the chemical species,
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Altlabel
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ChemicalEntity
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Elucidation
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Any constitutionally or isotopically distinct atom, molecule, ion, ion pair, radical, radical ion, complex, conformer etc., identifiable as a separately distinguishable entity that can undergo a chemical reaction.
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Example
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Hydrogen molecule is an adequate definition of a certain molecular entity for some purposes, whereas for others it is necessary to distinguish the electronic state and/or vibrational state and/or nuclear spin, etc. of the hydrogen molecule.
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Example
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Methane, may mean a single molecule of CH4 (molecular entity) or a molar amount, specified or not (chemical species), participating in a reaction. The degree of precision necessary to describe a molecular entity depends on the context.
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Example
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Hydrogen molecule is an adequate definition of a certain molecular entity for some purposes, whereas for others it is necessary to distinguish the electronic state and/or vibrational state and/or nuclear spin, etc. of the hydrogen molecule.
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Example
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Methane, may mean a single molecule of CH4 (molecular entity) or a molar amount, specified or not (chemical species), participating in a reaction. The degree of precision necessary to describe a molecular entity depends on the context.
An entity is called essential if removing one direct part will lead to a change in entity class. An entity is called redundand if removing one direct part will not lead to a change in entity class.
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Comment
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This definition states that this object is a non-periodic set of atoms or a set with a finite periodicity. Removing an atom from the state will result in another type of atom_based state. e.g. you cannot remove H from H₂0 without changing the molecule type (essential). However, you can remove a C from a nanotube (redundant). C60 fullerene is a molecule, since it has a finite periodicity and is made of a well defined number of atoms (essential). A C nanotube is not a molecule, since it has an infinite periodicity (redundant).
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Altlabel
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ChemicalSubstance
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Elucidation
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An atom_based state defined by an exact number of e-bonded atomic species and an electron cloud made of the shared electrons.
The class of individuals standing for causally convex interacting systems.
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Conceptualisation
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It is natural to define entities made or more than one smaller parts as object according to some unity criteria. One of the most general one applicable to causal interacting systems is to ask that all the quantum parts of the system are part of elementaries whose paths start and end within the entitiy. We call this causal convexity. In other words, causal convexity excludes all quantums that leave the system (no more interacting), or that are not yet part of it (not yet interacting). So, a photon leaving a body is not part of a convex system, while a real photon that is the carrier of clasical electromagnetic interaction between two molecular parts of the body, is part of the convex body. A physical phenomenon is defined as a causally non-convex interacting system, complement of causally convex interacting system.
The scope of the physical particle definition goes from the elementary particles to molecules, as fundamental constituents of substances.
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Altlabel
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Particle
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Elucidation
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A well defined physical entity, elementary or composite, usually treated as a singular unit, that is found at scales spanning from the elementary particles to molecules, as fundamental constituents of larger scale substances (as the etymology of "particle" suggests).
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Definition
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The union of hadron and lepton, or fermion and bosons.
This class is the practical implementation of the EMMO pluralistic approach for which the only objective categorization is provided by the Universe individual and all the Quantum individuals. Between these two extremes, there are several subjective ways to categorize real world objects, each one provide under a 'Perspective' subclass.
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Elucidation
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The class of causal objects that stand for world objects according to a specific representational perspective.
The ampere, symbol A, is the SI unit of electric current. It is defined by taking the fixed numerical value of the elementary charge e to be 1.602176634×10−19 when expressed in the unit C, which is equal to A s, where the second is defined in terms of ∆νCs.
The SI derived unit of activity, usually meaning radioactivity. "Radioactivity" is caused when atoms disintegrate, ejecting energetic particles. One becquerel is the radiation caused by one disintegration per second; this is equivalent to about 27.0270 picocuries (pCi). The unit is named for a French physicist, Antoine-Henri Becquerel (1852-1908), the discoverer of radioactivity. Note: both the becquerel and the hertz are basically defined as one event per second, yet they measure different things. The hertz is used to measure the rates of events that happen periodically in a fixed and definite cycle. The becquerel is used to measure the rates of events that happen sporadically and unpredictably, not in a definite cycle.
The candela, symbol cd, is the SI unit of luminous intensity in a given direction. It is defined by taking the fixed numerical value of the luminous efficacy of monochromatic radiation of frequency 540×1012 Hz, Kcd, to be 683 when expressed in the unit lm W−1, which is equal to cd sr W−1, or cd sr kg−1 m−2 s3, where the kilogram, metre and second are defined in terms of h, c and ∆νCs.
The SI unit of electric charge. One coulomb is the amount of charge accumulated in one second by a current of one ampere. Electricity is actually a flow of charged particles, such as electrons, protons, or ions. The charge on one of these particles is a whole-number multiple of the charge e on a single electron, and one coulomb represents a charge of approximately 6.241 506 x 1018 e. The coulomb is named for a French physicist, Charles-Augustin de Coulomb (1736-1806), who was the first to measure accurately the forces exerted between electric charges.
Celsius, also known as centigrade, is a scale and unit of measurement for temperature. It can refer to a specific temperature on the Celsius scale as well as a unit to indicate a temperature interval, a difference between two temperatures or an uncertainty. This definition fixes the magnitude of both the degree Celsius and the kelvin as precisely 1 part in 273.16 (approximately 0.00366) of the difference between absolute zero and the triple point of water. Thus, it sets the magnitude of one degree Celsius and that of one kelvin as exactly the same. Additionally, it establishes the difference between the two scales' null points as being precisely 273.15 °C.
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Elucidation
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Measurement unit for Celsius temperature. This unit can only be used for expressing temperature differences.
The SI unit of electric capacitance. Very early in the study of electricity scientists discovered that a pair of conductors separated by an insulator can store a much larger charge than an isolated conductor can store. The better the insulator, the larger the charge that the conductors can hold. This property of a circuit is called capacitance, and it is measured in farads. One farad is defined as the ability to store one coulomb of charge per volt of potential difference between the two conductors. This is a natural definition, but the unit it defines is very large. In practical circuits, capacitance is often measured in microfarads, nanofarads, or sometimes even in picofarads (10⁻¹² farad, or trillionths of a farad). The unit is named for the British physicist Michael Faraday (1791-1867), who was known for his work in electricity and electrochemistry.
The SI unit of radiation dose. Radiation carries energy, and when it is absorbed by matter the matter receives this energy. The dose is the amount of energy deposited per unit of mass. One gray is defined to be the dose of one joule of energy absorbed per kilogram of matter, or 100 rad. The unit is named for the British physician L. Harold Gray (1905-1965), an authority on the use of radiation in the treatment of cancer.
The SI unit of electric inductance. A changing magnetic field induces an electric current in a loop of wire (or in a coil of many loops) located in the field. Although the induced voltage depends only on the rate at which the magnetic flux changes, measured in webers per second, the amount of the current depends also on the physical properties of the coil. A coil with an inductance of one henry requires a flux of one weber for each ampere of induced current. If, on the other hand, it is the current which changes, then the induced field will generate a potential difference within the coil: if the inductance is one henry a current change of one ampere per second generates a potential difference of one volt. The henry is a large unit; inductances in practical circuits are measured in millihenrys (mH) or microhenrys (μH). The unit is named for the American physicist Joseph Henry (1797-1878), one of several scientists who discovered independently how magnetic fields can be used to generate alternating currents.
The hertz (symbol Hz) is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications, such as the frequency of musical tones. The word "hertz" is named for Heinrich Rudolf Hertz, who was the first to conclusively prove the existence of electromagnetic waves.
The SI unit of work or energy, defined to be the work done by a force of one newton acting to move an object through a distance of one meter in the direction in which the force is applied. Equivalently, since kinetic energy is one half the mass times the square of the velocity, one joule is the kinetic energy of a mass of two kilograms moving at a velocity of 1 m/s.
A unit of catalytic activity used especially in the chemistry of enzymes. A catalyst is a substance that starts or speeds a chemical reaction. Enzymes are proteins that act as catalysts within the bodies of living plants and animals. A catalyst has an activity of one katal if it enables a reaction to proceed at the rate of one mole per second.
The kelvin, symbol K, is the SI unit of thermodynamic temperature. It is defined by taking the fixed numerical value of the Boltzmann constant k to be 1.380649×10−23 when expressed in the unit J K−1, which is equal to kg m2 s−2 K−1, where the kilogram, metre and second are defined in terms of h, c and ∆νCs.
The kilogram, symbol kg, is the SI unit of mass. It is defined by taking the fixed numerical value of the Planck constant h to be 6.62607015×10−34 when expressed in the unit J s, which is equal to kg m2 s−1, where the metre and the second are defined in terms of c and ∆νCs.
The SI unit for measuring the flux of light being produced by a light source or received by a surface. The intensity of a light source is measured in candelas. One lumen represents the total flux of light emitted, equal to the intensity in candelas multiplied by the solid angle in steradians into which the light is emitted. A full sphere has a solid angle of 4·π steradians. A light source that uniformly radiates one candela in all directions has a total luminous flux of 1 cd·4π sr = 4π cd·sr ≈ 12.57 lumens. "Lumen" is a Latin word for light.
The SI unit for measuring the illumination (illuminance) of a surface. One lux is defined as an illumination of one lumen per square meter or 0.0001 phot. In considering the various light units, it's useful to think about light originating at a point and shining upon a surface. The intensity of the light source is measured in candelas; the total light flux in transit is measured in lumens (1 lumen = 1 candelau·steradian); and the amount of light received per unit of surface area is measured in lux (1 lux = 1 lumen/square meter). One lux is equal to approximately 0.09290 foot candle.
The metre, symbol m, is the SI unit of length. It is defined by taking the fixed numerical value of the speed of light in vacuum c to be 299792458 when expressed in the unit m s−1, where the second is defined in terms of ∆νCs.
The mole, symbol mol, is the SI unit of amount of substance. One mole contains exactly 6.022 140 76 × 1023 elementary entities. This number is the fixed numerical value of the Avogadro constant, NA, when expressed in the unit mol−1 and is called the Avogadro number. The amount of substance, symbol n, of a system is a measure of the number of specified elementary entities. An elementary entity may be an atom, a molecule, an ion, an electron, any other particle or specified group of particles.
The "Newton" is the SI unit of force. A force of one newton will accelerate a mass of one kilogram at the rate of one meter per second per second. The newton is named for Isaac Newton (1642-1727), the British mathematician, physicist, and natural philosopher. He was the first person to understand clearly the relationship between force (F), mass (m), and acceleration (a) expressed by the formula F = m·a.
The SI unit of pressure. The pascal is the standard pressure unit in the MKS metric system, equal to one newton per square meter or one "kilogram per meter per second per second." The unit is named for Blaise Pascal (1623-1662), French philosopher and mathematician, who was the first person to use a barometer to measure differences in altitude.
Derived units are defined as products of powers of the base units. When the numerical factor of this product is one, the derived units are called coherent derived units. The base and coherent derived units of the SI form a coherent set, designated the set of coherent SI units.
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Elucidation
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A unit that can be expressed as a product of powers of SI base units with no pre-factor of offset.
The second, symbol s, is the SI unit of time. It is defined by taking the fixed numerical value of the caesium frequency ∆νCs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be 9192631770 when expressed in the unit Hz, which is equal to s−1.
Siemens is the SI unit of electric conductance, susceptance, and admittance. The most important property of a conductor is the amount of current it will carry when a voltage is applied. Current flow is opposed by resistance in all circuits, and by also by reactance and impedance in alternating current circuits. Conductance, susceptance, and admittance are the inverses of resistance, reactance, and impedance, respectively. To measure these properties, the siemens is the reciprocal of the ohm. In other words, the conductance, susceptance, or admittance, in siemens, is simply 1 divided by the resistance, reactance or impedance, respectively, in ohms. The unit is named for the German electrical engineer Werner von Siemens (1816-1892).
Although the sievert has the same dimensions as the gray (i.e. joules per kilogram), it measures a different quantity. To avoid any risk of confusion between the absorbed dose and the equivalent dose, the corresponding special units, namely the gray instead of the joule per kilogram for absorbed dose and the sievert instead of the joule per kilogram for the dose equivalent, should be used.
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Elucidation
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SI unit for equivalent doseof ionizing radiation. Sievert is derived from absorbed dose, but takes into account the biological effectiveness of the radiation, which is dependent on the radiation type and energy.
The SI unit of flux density (or field intensity) for magnetic fields (also called the magnetic induction). The intensity of a magnetic field can be measured by placing a current-carrying conductor in the field. The magnetic field exerts a force on the conductor, a force which depends on the amount of the current and on the length of the conductor. One tesla is defined as the field intensity generating one newton of force per ampere of current per meter of conductor. Equivalently, one tesla represents a magnetic flux density of one weber per square meter of area. A field of one tesla is quite strong: the strongest fields available in laboratories are about 20 teslas, and the Earth's magnetic flux density, at its surface, is about 50 microteslas. The tesla, defined in 1958, honors the Serbian-American electrical engineer Nikola Tesla (1856-1943), whose work in electromagnetic induction led to the first practical generators and motors using alternating current.
The volt is the unit of electric potential difference—electric potential difference is also known as voltage. The size of 1 volt is officially defined as the potential difference between two points of a wire carrying a current of 1 ampere when the power dissipated in the wire is 1 watt.
The SI unit of power. Power is the rate at which work is done, or (equivalently) the rate at which energy is expended. One watt is equal to a power rate of one joule of work per second of time. This unit is used both in mechanics and in electricity, so it links the mechanical and electrical units to one another. In mechanical terms, one watt equals about 0.001 341 02 horsepower (hp) or 0.737 562 foot-pound per second (lbf/s). In electrical terms, one watt is the power produced by a current of one ampere flowing through an electric potential of one volt. The name of the unit honors James Watt (1736-1819), the British engineer whose improvements to the steam engine are often credited with igniting the Industrial Revolution.
The SI unit of magnetic flux. "Flux" is the rate (per unit of time) at which something crosses a surface perpendicular to the flow. The weber is a large unit, equal to 10⁸ maxwells, and practical fluxes are usually fractions of one weber. The weber is the magnetic flux which, linking a circuit of one turn, would produce in it an electromotive force of 1 volt if it were reduced to zero at a uniform rate in 1 second. In SI base units, the dimensions of the weber are (kg·m²)/(s²·A). The weber is commonly expressed in terms of other derived units as the Tesla-square meter (T·m²), volt-seconds (V·s), or joules per ampere (J/A).
