isqx (iso80000)
The public API is the top level isqx module.
Units and quantities as defined by the International System of Quantities (ISQ), as specified in the ISO/IEC 80000 standard.
Domain-specific units and quantities should be defined elsewhere, in their own modules (e.g. aerospace) for performance reasons.
See: isqx._citations.SI, isqx._citations.IUPAP1, isqx._citations.SP811 isqx._citations.CODATA2022, isqx._citations.ISO_80000_2, isqx._citations.ISO_80000_3, isqx._citations.ISO_80000_4, isqx._citations.ISO_80000_5, isqx._citations.IEC_80000_6, isqx._citations.IEV, isqx._citations.ISO_80000_7, isqx._citations.ISO_80000_8, isqx._citations.ISO_80000_9, isqx._citations.ISO_80000_10, isqx._citations.ISO_80000_11, isqx._citations.ISO_80000_12, isqx._citations.ISO_80000_13, isqx._citations.MP_UNITS.
Quantity kinds in this module are largely derived from Wikidata.
SR = Dimensionless('steradian')
Steradian, a unit of solid angle. Not to be confused with m² m⁻².
HZ = (S**-1)["frequency"].alias("hertz", allow_prefix=True)
Unit of frequency. Shall only be used for periodic phenomena.
Volt, a unit of electric potential difference
and voltage, also known as electric tension or tension.
Siemens, a unit of electric conductance.
CELSIUS = Translated(K, Decimal('-273.15'), 'celsius')
Celsius, a unit of thermodynamic temperature. An absolute, translated scale. Cannot be composed with other units.
BQ = (S**-1)["activity"].alias(
"becquerel", allow_prefix=True
)
Unit of activity referred to a radionuclide. Shall only be used for stochastic processes in activity referred to a radionuclide. Not to be confused with "radioactivity".
Gray, a unit of absorbed dose and kerma.
Sievert, a unit of dose equivalent.
Speed of electromagnetic waves in vacuum, defined by the 17th CGPM (1983).
Planck constant, (CODATA 2022).
CONST_REDUCED_PLANCK: Annotated[LazyProduct, J * S] = (
LazyProduct((CONST_PLANCK, (2, -1), (_PI, -1)))
)
Elementary charge, (CODATA 2022).
CONST_PERMEABILITY_VACUUM: Annotated[
Decimal, H * M**-1, StdUncertainty(20)
] = Decimal("1.25663706127e-6")
Permeability of free space, (CODATA 2022).
CONST_PERMITTIVITY_VACUUM: Annotated[
LazyProduct, F * M**-1
] = LazyProduct(
(
(CONST_PERMEABILITY_VACUUM, -1),
(CONST_SPEED_OF_LIGHT_VACUUM, -2),
)
)
Permittivity of free space, (CODATA 2022).
Boltzmann constant, (CODATA 2022).
Avogadro constant, (CODATA 2022).
CONST_STEFAN_BOLTZMANN: Annotated[
LazyProduct, W * M**-2 * K**-4
] = LazyProduct(
(
2,
(_PI, 5),
(CONST_BOLTZMANN, 4),
(15, -1),
(CONST_SPEED_OF_LIGHT_VACUUM, -2),
(CONST_PLANCK, -3),
)
)
Stefan-Boltzmann constant, (CODATA 2022).
CONST_FIRST_RADIATION: Annotated[
LazyProduct, W * M**-2
] = LazyProduct(
(2, _PI, CONST_PLANCK, (CONST_SPEED_OF_LIGHT_VACUUM, 2))
)
First radiation constant, (CODATA 2022).
CONST_SECOND_RADIATION: Annotated[LazyProduct, M * K] = (
LazyProduct(
(
CONST_PLANCK,
CONST_SPEED_OF_LIGHT_VACUUM,
(CONST_BOLTZMANN, -1),
)
)
)
Second radiation constant, (CODATA 2022).
Standard acceleration of gravity, defined by the 3rd CGPM (1901).
Conventional density of water. For use in isqx.MMH2O.
Standard pressure, defined by the 10th CGPM (1954).
Standard pressure, for use in specifying the properties of substances, defined by the IUPAC (1982).
AU = (149597870700 * M).alias('astronomical_unit')
Astronomical unit, as defined by IAU 2012 Resolution B2.
LY = (CONST_SPEED_OF_LIGHT_VACUUM * YEAR).alias(
"light_year", allow_prefix=True
)
DEG = (LazyProduct((_PI, (180, -1))) * RAD).alias('degree')
Degrees (°), a unit of plane angle.
HECTARE = (100 * ARE).alias('hectare')
Hectare, a unit of land area, as adopted by the CIPM in 1879.
TONNE = (1000 * KG).alias('tonne', allow_prefix=True)
Tonne, a unit of mass, also known as the metric ton in the U.S.
Unified atomic mass unit, also known as the dalton.
EV = (CONST_ELEMENTARY_CHARGE * J).alias(
"electronvolt", allow_prefix=True
)
BEL = Log(_RATIO, base=10).alias('bel', allow_prefix=True)
Bel, a logarithmic unit of a generic ratio. When used for a power quantity, it is \(L_B = \log_{10}(P/P_{ref})\). The decibel (dB) is more commonly used.
Neper, a logarithmic unit of a generic ratio. When used for a root-power quantity, it is \(L_{Np} = \ln(F/F_{ref})\).
A decibel level for a root-power (field) quantity, \(L_{dB} = 20 \log_{10}(\text{ratio})\).
CONST_DBU_REF: Annotated[LazyProduct, V] = LazyProduct(
((Decimal("0.6"), Fraction(1, 2)),)
)
Decibel, voltage relative to ~0.775 volt (the voltage that dissipates 1 milliwatt in a 600 ohm load).
Decibel, reflectivity factor Z relative to 1 mm⁶ m⁻³ for weather radar.
MMHG = (
LazyProduct((CONST_DENSITY_HG, CONST_STANDARD_GRAVITY))
* (MILLI * M)
).alias("millimeter_of_hg")
Millimeter of mercury, a unit of pressure.
MMH2O = (
LazyProduct((CONST_DENSITY_H2O, CONST_STANDARD_GRAVITY))
* (MILLI * M)
).alias("millimeter_of_h2o")
Millimeter of water (conventional), a unit of pressure.
Rem (roentgen equivalent in man), a legacy unit of dose equivalent. The SI unit sievert is preferred.
Fermi, an obsolete name for the femtometer.
ATM = (CONST_STANDARD_PRESSURE_ATM * PA).alias("atmosphere")
Standard atmosphere, a unit of pressure.
WIDTH = LENGTH['width']
Horizontal dimension of an entity.
HEIGHT = LENGTH['height']
Distance between the lowest and highest end of an object.
More specifically, ICAO defines it as "the vertical distance
of a level, a point or an object considered as a point, measured from a specific
datum.". Specify the particular datum using the isqx.OriginAt tag.
ALTITUDE = LENGTH['altitude', RELATIVE_TO_MSL]
The vertical distance of a level, a point or an object considered as a point, measured from the mean sea level (as defined by ICAO).
For the different kinds of altitude, see the isqx.aerospace module.
ELEVATION = LENGTH['elevation', RELATIVE_TO_MSL]
The vertical distance of a point or a level, on or affixed to the surface of the Earth, measured from mean sea level (as defined by ICAO).
THICKNESS = LENGTH['thickness']
Extent from one surface to the opposite, usually in the smallest solid dimension.
RADIAL_DISTANCE = DISTANCE['radial']
The radial distance within a closed non-intersecting
curve/surface. Use isqx.OriginAt to specify the origin.
Vector representing the position of a point with respect to a given origin
and axes. Specify the origin with the isqx.OriginAt tag and the coordinate
system (e.g. isqx.CARTESIAN).
Vector that is the shortest distance from the initial to the final position of a point P.
A measure of how much a curve deviates from being a straight line.
Quantity that expresses the extent of a two-dimensional surface or shape, or planar lamina, in the plane.
SURFACE_ELEMENT = AREA[DIFFERENTIAL]
See: https://en.wikipedia.org/wiki/Surface_integral
VOLUME_ELEMENT = VOLUME[DIFFERENTIAL]
See: https://en.wikipedia.org/wiki/Volume_element
A measure for how wide an angle is. For signed angles, use angular displacement.
ANGULAR_DISPLACEMENT_CCW = ANGLE[
"displacement", "counterclockwise"
]
Displacement measured angle-wise when a body is in circular or rotational motion, positive counterclockwise.
ANGULAR_DISPLACEMENT_CW = ANGLE["displacement", "clockwise"]
Change in the angular position of a point, positive clockwise.
PHASE_ANGLE = ANGLE['phase']
Angular measure of the phase of a complex number.
Physical quantity for describing the temporal distance between events.
PERIOD = DURATION['period']
Smallest temporal unit after which a process repeats.
Measure for the response of a dynamic system to a change of the system input.
Angular velocity, but positive clockwise.
Angular acceleration, but positive clockwise.
NUMBER_OF_REVOLUTIONS = Dimensionless('n_revolutions')
Physical quantity; number of revolutions of a rotating body or turns in a coil.
ROTATIONAL_FREQUENCY = QtyKind(
NUMBER_OF_REVOLUTIONS * S**-1
)
Vector pointing in the direction of a wave and whose magnitude is equal to the wavenumber.
See: https://en.wikipedia.org/wiki/Wave_vector
PHASE_SPEED = SPEED['phase']
GROUP_SPEED = SPEED['group']
Speed at which a wave's envelope propagates in space.
LOGARITHMIC_DECREMENT = QtyKind(
Dimensionless("logarithmic_decrement")
)
Measure for the damping of an oscillator.
Property of matter to resist changes of the state of motion and to attract other bodies.
RELATIVE_DENSITY = Dimensionless('specific_gravity')
At a point on Earth, vector sum of gravitational and centrifugal acceleration.
STATIC_FRICTION = FRICTION['static']
Subconcept of friction.
NORMAL_FORCE = FORCE['normal']
The component of a contact force that is perpendicular to the surface that an object contacts.
TANGENTIAL_FORCE = FORCE['tangential']
The component of a contact force that is parallel to the surface that an object contacts.
COEFFICIENT_OF_STATIC_FRICTION = Dimensionless(
"coefficient_of_friction_static"
)
COEFFICIENT_OF_KINETIC_FRICTION = Dimensionless(
"coefficient_of_friction_kinetic"
)
ROLLING_RESISTANCE_FACTOR = Dimensionless(
"rolling_resistance_factor"
)
DRAG_COEFFICIENT = Dimensionless('drag_coefficient')
Dimensionless parameter to quantify fluid resistance.
Measure of the extent to which an object will continue to rotate in the absence of an applied torque.
GAUGE_PRESSURE = PRESSURE['gauge']
DYNAMIC_PRESSURE = PRESSURE['dynamic']
See: https://en.wikipedia.org/wiki/Dynamic_pressure
STRESS_TENSOR = STRESS[TENSOR_SECOND_ORDER]
Tensor that describes the state of stress at a point inside a material.
STRAIN_TENSOR = STRAIN[TENSOR_SECOND_ORDER, CARTESIAN]
LINEAR_STRAIN = Dimensionless('linear_strain')
SHEAR_STRAIN = Dimensionless('shear_strain')
VOLUMETRIC_STRAIN = Dimensionless('volumetric_strain')
POISSONS_RATIO = Dimensionless('poissons_ratio')
A mechanical property that measures stiffness of a solid material.
Measure of how incompressible / resistant to compressibility a substance is.
MOMENT_OF_INERTIA = QtyKind(
KG * M**2, (TENSOR_SECOND_ORDER,)
)
See: https://en.wikipedia.org/wiki/Second_polar_moment_of_area
Concept in structural analysis.
Physical property of a moving fluid.
Characteristic of a fluid.
MECHANICAL_ENERGY = ENERGY['mechanical']
LINE_ELEMENT = QtyKind(
M, (DIFFERENTIAL, "displacement", VECTOR)
)
See: https://en.wikipedia.org/wiki/Line_element
Energy transferred to an object via the application of force on it through a displacement.
MECHANICAL_EFFICIENCY = Dimensionless(
"efficiency_mechanical"
)
Thermodynamic temperature, an absolute measure of temperature.
REFERENCE_TEMPERATURE = TEMPERATURE[
"reference", "surrounding"
]
HOT_RESERVOIR_TEMPERATURE = TEMPERATURE['hot_reservoir']
Absolute temperature of hot reservoir.
COLD_RESERVOIR_TEMPERATURE = TEMPERATURE['cold_reservoir']
Absolute temperature of cold reservoir.
ISOTHERMAL_COMPRESSIBILITY = COMPRESSIBILITY['isothermal']
Negative relative change of volume per change of pressure at constant temperature.
ISENTROPIC_COMPRESSIBILITY = COMPRESSIBILITY['isentropic']
Energy that is transferred from one body to another as the result of a difference in temperature.
INEXACT_DIFFERENTIAL_HEAT = HEAT[INEXACT_DIFFERENTIAL]
Objects' resistance to heat transfer; reciprocal of thermal conductance.
Objects' ability to transfer heat; reciprocal of thermal resistance.
Thermal property describing the energy required to change a material's temperature.
HEAT_CAPACITY_P = HEAT_CAPACITY['constant_pressure']
Heat capacity at constant pressure (isobaric).
HEAT_CAPACITY_V = HEAT_CAPACITY['constant_volume']
Heat capacity at constant volume (isochoric).
SPECIFIC_HEAT_CAPACITY_P = SPECIFIC_HEAT_CAPACITY[
"constant_pressure"
]
Specific heat capacity at constant pressure (isobaric).
SPECIFIC_HEAT_CAPACITY_V = SPECIFIC_HEAT_CAPACITY[
"constant_volume"
]
Specific heat capacity at constant volume (isochoric).
SPECIFIC_HEAT_CAPACITY_SAT = SPECIFIC_HEAT_CAPACITY[
"saturation"
]
HEAT_CAPACITY_RATIO = Dimensionless('heat_capacity_ratio')
Thermodynamic ratio of isobaric to isochoric specific heat capacities.
ISENTROPIC_EXPONENT = Dimensionless('isentropic_exponent')
Physical property of the state of a system, measure of disorder.
INTERNAL_ENERGY = ENERGY['internal']
State quantity, energy of a system whose change is the heat transferred to the system minus the work done by the system (closed system, no chemical reactions).
HELMHOLTZ_ENERGY = ENERGY['helmholtz']
Thermodynamic potential.
SPECIFIC_INTERNAL_ENERGY = SPECIFIC_ENERGY['internal']
SPECIFIC_ENTHALPY = SPECIFIC_ENERGY['enthalpy']
SPECIFIC_HELMHOLTZ_ENERGY = SPECIFIC_ENERGY['helmholtz']
SPECIFIC_GIBBS_ENERGY = SPECIFIC_ENERGY['gibbs']
THERMAL_EFFICIENCY = Dimensionless('efficiency_thermal')
CARNOT_EFFICIENCY = Dimensionless(
"efficiency_thermal_carnot"
)
Efficiency of an ideal heat engine operating according to the Carnot process.
WATER_MASS_CONCENTRATION = MASS_CONCENTRATION['water']
WATER_VAPOUR_MASS_CONCENTRATION = MASS_CONCENTRATION[
"water_vapour"
]
WATER_VAPOUR_MASS_CONCENTRATION_AT_SATURATION = (
WATER_VAPOUR_MASS_CONCENTRATION["saturation"]
)
WATER_TO_DRY_MATTER_MASS_RATIO = Dimensionless(
"mass_ratio_water_to_dry_matter"
)
WATER_VAPOUR_TO_DRY_GAS_MASS_RATIO = Dimensionless(
"mass_ratio_water_vapour_to_dry_gas"
)
Physical / meteorological quantity.
WATER_VAPOUR_TO_DRY_GAS_MASS_RATIO_AT_SATURATION = (
WATER_VAPOUR_TO_DRY_GAS_MASS_RATIO["saturation"]
)
Also known as mixing ratio.
MASS_FRACTION = Dimensionless('mass_fraction')
WATER_MASS_FRACTION = MASS_FRACTION['water']
DRY_MATTER_MASS_FRACTION = MASS_FRACTION['dry_matter']
PARTIAL_PRESSURE = PRESSURE['partial']
Hypothetical pressure of gas if it alone occupied the volume of the mixture at the same temperature.
WATER_VAPOUR_PARTIAL_PRESSURE = PARTIAL_PRESSURE[
"water_vapour"
]
Saturation vapour pressure of water.
SATURATION_WATER_VAPOUR_PARTIAL_PRESSURE = (
WATER_VAPOUR_PARTIAL_PRESSURE["saturation"]
)
RELATIVE_HUMIDITY = Dimensionless('relative_humidity')
Ratio of the partial pressure of water vapor in humid air to the equilibrium vapor pressure of water at a given temperature.
RELATIVE_MASS_CONCENTRATION_VAPOUR = Dimensionless(
"relative_mass_concentration_vapour"
)
Quotient of the mass concentration of water vapor and the mass concentration at saturation at a given temperature.
RELATIVE_MASS_RATIO_VAPOUR = Dimensionless(
"relative_mass_ratio_vapour"
)
Quotient of the mass ratio of water vapor to dry air and the mass ratio of water vapor to dry air at saturation at a given temperature. Approximation to relative humidity.
DEW_POINT = TEMPERATURE['dew_point']
The temperature at which air becomes saturated with water vapour.
Physical property that quantifies an object's interaction with electric fields.
Vector physical quantity measuring the separation of positive and negative electrical charges within a system.
Vector physical quantity of electrostatics and electrodynamics.
Line integral of the electric field.
In circuit theory, for a conductor, electric potential difference between two points.
INDUCED_VOLTAGE = VOLTAGE['induced']
See: https://en.wikipedia.org/wiki/Electromagnetic_induction
Vector field related to displacement current and flux density.
Physical quantity, measure of the resistance to the electric field.
RELATIVE_PERMITTIVITY = Dimensionless(
"relative_permittivity"
)
ELECTRIC_SUSCEPTIBILITY = Dimensionless(
"electric_susceptibility"
)
Degree of polarization.
Surface integral of the electric flux density; measured in coulombs.
DISPLACEMENT_CURRENT_DENSITY = CURRENT_DENSITY[
"displacement"
]
DISPLACEMENT_CURRENT = CURRENT['displacement']
TOTAL_CURRENT = CURRENT['total']
TOTAL_CURRENT_DENSITY = CURRENT_DENSITY['total']
Vector physical quantity describing production of a potential difference across a conductor when it is exposed to a varying magnetic field.
Integral of the magnetic vector potential along a path.
LINKED_MAGNETIC_FLUX = MAGNETIC_FLUX['linked']
TOTAL_MAGNETIC_FLUX = MAGNETIC_FLUX['total']
Highest value of magnetic flux produced by a current loop in circuit theory. The definition is consistent with the more general definition of linked flux.
Strength of a magnetic field.
Measure of the ability of a material to support the formation of a magnetic field within itself.
RELATIVE_PERMEABILITY = Dimensionless(
"relative_permeability"
)
MAGNETIC_SUSCEPTIBILITY = Dimensionless(
"magnetic_susceptibility"
)
Measure of how much a material will become magnetized in an applied magnetic field.
Physical quantity; measured in weber metre.
Measure of the ability of a ferromagnetic material to withstand an external magnetic field without becoming demagnetized.
ELECTROMAGNETIC_ENERGY_DENSITY = ENERGY_DENSITY[
"electromagnetic"
]
SPEED_OF_LIGHT = PHASE_SPEED['light']
Scalar potential whose negative gradient is the magnetic field strength.
N_TURNS_WINDING = Dimensionless('n_turns_winding')
A quantity representing the sum of magnetizing forces along a circuit.
In physics, the ratio of magnetomotive force to magnetic flux; the magnetic analogue of electrical resistance.
MUTUAL_INDUCTANCE = INDUCTANCE['mutual']
COUPLING_FACTOR = Dimensionless('coupling_factor')
LEAKAGE_FACTOR = Dimensionless('leakage_factor')
INSTANTANEOUS_POWER = POWER['instantaneous']
PHASE_DIFFERENCE = PHASE_ANGLE[DELTA]
IMPEDANCE_OF_VACUUM = IMPEDANCE['vacuum']
Physical constant relating the magnitudes of the electric and magnetic fields of electromagnetic radiation travelling through free space.
A circuit element's opposition to changes in electric current due to its inductance or capacitance.
Real part of the complex admittance.
Imaginary part of the admittance.
QUALITY_FACTOR = Dimensionless('quality_factor')
Dimensionless quantity in electromagnetism.
DISSIPATION_FACTOR = Dimensionless('loss_factor')
ACTIVE_POWER = POWER['active']
POWER_FACTOR = Dimensionless('power_factor')
Quantity in electromagnetism.
Type of electrical power.
Quantity in electromagnetism.
ACTIVE_ENERGY = ENERGY['active']
REFRACTIVE_INDEX = Dimensionless('refractive_index')
RADIANT_ENERGY_DENSITY = ENERGY_DENSITY['radiant']
SPECTRAL_RADIANT_ENERGY_DENSITY_WAVELENGTH = QtyKind(
J * M**-4, ("radiant", "spectral", "wavelength")
)
SPECTRAL_RADIANT_ENERGY_DENSITY_WAVENUMBER = QtyKind(
J * M**-2, ("radiant", "spectral", "wavenumber")
)
Areal density of radiant intensity in a given direction.
LUMINOUS_EFFICIENCY = Dimensionless('luminous_efficiency')
Specify the photometric condition with tags.
SPECTRAL_LUMINOUS_EFFICIENCY = Dimensionless(
"spectral_luminous_efficiency"
)
Spectral sensitivity of human visual perception of brightness.
Specify the photometric condition with tags.
See: https://www.electropedia.org/iev/iev.nsf/display?openform&ievref=845-21-089
Photometric measure of the luminous intensity per area of light travelling in a given direction.
NUMBER_OF_PHOTONS = Dimensionless('photon_number')
Area density of the photon intensity in a specified direction.
CIE_COLOUR_MATCHING_FUNCTIONS_1931 = Dimensionless(
"cie_colour_matching_functions_1931"
)
CIE_COLOUR_MATCHING_FUNCTIONS_1964 = Dimensionless(
"cie_colour_matching_functions_1964"
)
CHROMATICITY_COORDINATES_1931 = Dimensionless(
"chromaticity_coordinates_1931"
)
See: https://en.wikipedia.org/wiki/CIE_1931_color_space
CHROMATICITY_COORDINATES_1964 = Dimensionless(
"chromaticity_coordinates_1964"
)
COLOUR_TEMPERATURE = TEMPERATURE['colour']
Property of light sources related to black-body radiation.
CORRELATED_COLOUR_TEMPERATURE = TEMPERATURE[
"correlated_colour"
]
Property of light stimulus related to human perception.
EMISSIVITY = Dimensionless('emissivity')
Effectiveness of an object in emitting thermal radiation.
EMISSIVITY_AT_SPECIFIC_WAVELENGTH = Dimensionless(
"emissivity_at_specific_wavelength"
)
Emissivity as a function of wavelength.
ABSORPTANCE = Dimensionless('absorptance')
LUMINOUS_ABSORPTANCE = ABSORPTANCE['luminous']
REFLECTANCE = Dimensionless('reflectance')
Capacity of an object to reflect light.
LUMINOUS_REFLECTANCE = REFLECTANCE['luminous']
TRANSMITTANCE = Dimensionless('transmittance')
LUMINOUS_TRANSMITTANCE = TRANSMITTANCE['luminous']
ABSORBANCE = -1 * Log(TRANSMITTANCE, base=10)
Common logarithm of the ratio of incident to transmitted radiant power through a material; the optical depth divided by ln(10).
NAPIERIAN_ABSORBANCE = -1 * Log(TRANSMITTANCE, base=_E)
RADIANCE_FACTOR = Dimensionless('radiance_factor')
LUMINANCE_FACTOR = Dimensionless('luminance_factor')
SPECTRAL_LUMINANCE_FACTOR = Dimensionless(
"spectral_luminance_factor"
)
REFLECTANCE_FACTOR = Dimensionless('reflectance_factor')
See: https://en.wikipedia.org/wiki/Reflectance
PROPAGATION_LENGTH_ABSORBING_AND_SCATTERING = (
PROPAGATION_LENGTH["absorbing", "scattering"]
)
Propagation length of a collimated beam at a point in an absorbing and scattering medium.
PROPAGATION_LENGTH_ABSORBING = PROPAGATION_LENGTH[
"absorbing"
]
Propagation length of a collimated beam at a point in an absorbing medium.
Instantaneous displacement of a particle from its equilibrium position in a medium as it transmits a sound wave.
SOUND_VOLUME_FLOW_RATE = VOLUME_FLOW_RATE['sound']
SOUND_ENERGY_DENSITY = ENERGY_DENSITY['sound']
SOUND_POWER = POWER['sound']
DB_SPL_AIR = (
20
* Log(
ratio(PA_SOUND_RMS, Quantity(20, MICRO * PA)),
base=10,
)
).alias("dB_spl_air")
Sound pressure level in air and other gases.
DB_SPL_WATER = (
20
* Log(
ratio(PA_SOUND_RMS, Quantity(1, MICRO * PA)),
base=10,
)
).alias("dB_spl_water")
Sound pressure level in water and other liquids.
DB_PWL = (
10
* Log(
ratio(
SOUND_POWER_TIME_AVERAGED(W),
Quantity(1, PICO * W),
),
base=10,
)
).alias("dB_pwl")
Sound power level.
DB_SEL_AIR = (
10
* Log(
ratio(
PA2_PERS_SOUND,
Quantity(400, (MICRO * PA) ** 2 * S),
),
base=10,
)
).alias("dB_sel_air")
Sound exposure level in air and other gases.
DB_SEL_WATER = (
10
* Log(
ratio(
PA2_PERS_SOUND,
Quantity(1, (MICRO * PA) ** 2 * S),
),
base=10,
)
).alias("dB_sel_water")
Sound exposure level in water and other liquids.
REVERBERATION_TIME = DURATION['reverberation']
Time after which the sound energy density has fallen to a certain fraction of the initial value after the sound source has stopped emitting.
NUMBER_OF_ENTITIES = Dimensionless('number_of_entities')
Discrete quantity; number of entities of a given kind in a system.
Extensive physical property.
EQUILIBRIUM_AMOUNT_OF_SUBSTANCE = AMOUNT_OF_SUBSTANCE[
"equilibrium"
]
RELATIVE_ATOMIC_MASS = Dimensionless("relative_atomic_mass")
RELATIVE_MOLECULAR_MASS = Dimensionless(
"relative_molecular_mass"
)
The particular molecule should be specified with tags.
MOLAR_INTERNAL_ENERGY = MOLAR_ENERGY['internal']
MOLAR_ENTHALPY = MOLAR_ENERGY['enthalpy']
MOLAR_HELMHOLTZ_ENERGY = MOLAR_ENERGY['helmholtz']
MOLAR_GIBBS_ENERGY = MOLAR_ENERGY['gibbs']
MOLECULAR_CONCENTRATION = NUMBER_DENSITY['molecular']
Measure of the concentration of a solute in a solution, or of any chemical species, in terms of amount of substance in a given volume; most commonly expressed in units of moles of solute per litre of solution.
MOLE_FRACTION = Dimensionless('molar_fraction')
LATENT_HEAT_OF_PHASE_TRANSITION = LATENT_HEAT[
"phase_transition"
]
Energy to be added to or removed from a system under constant temperature and pressure to undergo a complete phase transition.
ABSOLUTE_ACTIVITY = Dimensionless('absolute_activity')
Measure of the tendency of a substance to leave a phase.
STANDARD_CHEMICAL_POTENTIAL = CHEMICAL_POTENTIAL["standard"]
ACTIVITY_FACTOR = Dimensionless('activity_factor')
STANDARD_ABSOLUTE_ACTIVITY = ABSOLUTE_ACTIVITY['standard']
For a substance in a mixture, the absolute activity of the pure substance at the same temperature but at standard pressure (10⁵ Pa).
ACTIVITY_OF_SOLUTE = Dimensionless('activity_of_solute')
ACTIVITY_COEFFICIENT = Dimensionless("activity_coefficient")
Value accounting for thermodynamic non-ideality of mixtures.
STANDARD_ABSOLUTE_ACTIVITY_IN_SOLUTION = ABSOLUTE_ACTIVITY[
"standard", "solution"
]
Property of a solute in a solution.
ACTIVITY_OF_SOLVENT = Dimensionless('activity_of_solvent')
OSMOTIC_COEFFICIENT_OF_SOLVENT = Dimensionless(
"osmotic_factor_of_solvent"
)
Quantity characterizing the deviation of a solvent from ideal behavior.
STANDARD_ABSOLUTE_ACTIVITY_OF_SOLVENT = ABSOLUTE_ACTIVITY[
"standard", "of_solvent"
]
OSMOTIC_PRESSURE = PRESSURE['osmotic']
Measure of the tendency of a solution to take in pure solvent by osmosis.
STOICHIOMETRIC_NUMBER = Dimensionless(
"stoichiometric_number"
)
In the expression of a chemical reaction, number which is positive for products and negative for reactants.
Used to describe or characterise elements' or compounds' readiness to form bonds.
STANDARD_EQUILIBRIUM_CONSTANT = Dimensionless(
"standard_equilibrium_constant"
)
equilibrium_constant_pressure_basis(
sum_stoichiometric_numbers: Annotated[
Exponent, STOICHIOMETRIC_NUMBER_SUM
],
) -> QtyKind
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
sum_stoichiometric_numbers
|
Annotated[Exponent, STOICHIOMETRIC_NUMBER_SUM]
|
\(\sum_\text{B} \nu_\text{B}\) |
required |
Source code in src/isqx/_iso80000.py
1265 1266 1267 1268 1269 | |
equilibrium_constant_concentration_basis(
sum_stoichiometric_numbers: Annotated[
Exponent, STOICHIOMETRIC_NUMBER_SUM
],
) -> QtyKind
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
sum_stoichiometric_numbers
|
Annotated[Exponent, STOICHIOMETRIC_NUMBER_SUM]
|
\(\sum_\text{B} \nu_\text{B}\) |
required |
Source code in src/isqx/_iso80000.py
1272 1273 1274 1275 1276 1277 1278 | |
MICROCANONICAL_PARTITION_FUNCTION = Dimensionless(
"microcanonical_partition_function"
)
CANONICAL_PARTITION_FUNCTION = Dimensionless(
"canonical_partition_function"
)
GRAND_CANONICAL_PARTITION_FUNCTION = Dimensionless(
"grand_canonical_partition_function"
)
MOLECULAR_PARTITION_FUNCTION = Dimensionless(
"molecular_partition_function"
)
STATISTICAL_WEIGHT_OF_SUBSYSTEM = Dimensionless(
"statistical_weight_of_subsystem"
)
Number of microstates of a subsystem.
MULTIPLICITY = STATISTICAL_WEIGHT_OF_SUBSYSTEM[
"multiplicity"
]
Statistical weight of a quantum level.
Physical constant; the molar equivalent to the Boltzmann constant.
Proportionality constant in some physical laws.
THERMAL_DIFFUSION_RATIO = Dimensionless(
"thermal_diffusion_ratio"
)
THERMAL_DIFFUSION_FACTOR = Dimensionless(
"thermal_diffusion_factor"
)
Quantification of the electrical interactions between ions in solution.
DEGREE_OF_DISSOCIATION = Dimensionless(
"degree_of_dissociation"
)
Portion of dissociated molecules.
ELECTROLYTIC_CONDUCTIVITY = CONDUCTIVITY[
"electrolytic", TENSOR_SECOND_ORDER
]
Measure of the ability of a solution containing electrolytes to conduct electricity.
TRANSPORT_NUMBER_OF_ION = Dimensionless(
"transport_number_of_ion"
)
ANGLE_OF_OPTICAL_ROTATION = ANGLE['optical_rotation']
AREA_CROSS_SECTION_LINEARLY_POLARIZED = (
CROSS_SECTIONAL_AREA["linearly_polarized"]
)
Optical property of chiral chemical compounds.
ATOMIC_NUMBER = Dimensionless('atomic_number')
Number of protons found in the nucleus of an atom.
NEUTRON_NUMBER = Dimensionless('neutron_number')
Number of neutrons in a nuclide.
NUCLEON_NUMBER = Dimensionless('nucleon_number')
Number of heavy particles in the atomic nucleus.
UNIFIED_ATOMIC_MASS_CONSTANT = MASS[
"unified_atomic_mass_constant"
]
BOHR_RADIUS = LENGTH['bohr_radius']
HARTREE_ENERGY = ENERGY['hartree']
ATOMIC_MAGNETIC_DIPOLE_MOMENT = MAGNETIC_MOMENT['atomic']
Unit of magnetic moment (approx. 9.2 J/T); the magnetic dipole moment of an electron orbiting an atom with angular momentum ℏ in the Bohr model.
Physical constant of magnetic moment.
Intrinsic form of angular momentum as a property of quantum particles.
TOTAL_ANGULAR_MOMENTUM = ANGULAR_MOMENTUM['total']
ELECTRON_GYROMAGNETIC_RATIO = GYROMAGNETIC_RATIO["electron"]
QUANTUM_NUMBER = Dimensionless('quantum_number')
Notation for conserved quantities in physics and chemistry.
PRINCIPAL_QUANTUM_NUMBER = QUANTUM_NUMBER['principal']
One of four quantum numbers which are assigned to each electron in an atom to describe that electron's state.
ORBITAL_ANGULAR_MOMENTUM_QUANTUM_NUMBER = QUANTUM_NUMBER[
"orbital_angular_momentum"
]
Quantum number for an atomic orbital that determines its orbital angular momentum and describes the shape of the orbital, and is symbolized as ℓ.
MAGNETIC_QUANTUM_NUMBER = QUANTUM_NUMBER['magnetic']
Third in a set of four quantum numbers that distinguishes the orbitals available within a subshell and can be used to calculate the azimuthal component of the orientation of orbital in space.
SPIN_QUANTUM_NUMBER = QUANTUM_NUMBER['spin']
TOTAL_ANGULAR_MOMENTUM_QUANTUM_NUMBER = QUANTUM_NUMBER[
"total_angular_momentum"
]
Quantum number describing the total angular momentum of an atom.
NUCLEAR_SPIN_QUANTUM_NUMBER = QUANTUM_NUMBER["nuclear_spin"]
HYPERFINE_STRUCTURE_QUANTUM_NUMBER = QUANTUM_NUMBER[
"hyperfine_structure"
]
LANDE_FACTOR = Dimensionless('lande_factor')
g-factor for electron with spin and orbital angular momentum.
G_FACTOR_NUCLEUS = Dimensionless('g_factor_nucleus')
LARMOR_ANGULAR_FREQUENCY = ANGULAR_FREQUENCY['larmor']
LARMOR_PRECESSION_ANGULAR_FREQUENCY = ANGULAR_FREQUENCY[
"larmor_precession"
]
CYCLOTRON_ANGULAR_FREQUENCY = ANGULAR_FREQUENCY["cyclotron"]
GYRORADIUS = RADIUS['gyroradius']
Measure for the deviation of the nuclear charge density from spherical symmetry.
NUCLEAR_RADIUS = RADIUS['nuclear']
Measure of the size of atomic nuclei.
ELECTRON_RADIUS = RADIUS['electron']
COMPTON_WAVELENGTH = WAVELENGTH['compton']
In quantum mechanics, the wavelength of a photon whose energy is the same as the rest energy of a particle.
MASS_EXCESS = MASS['excess']
MASS_DEFECT = MASS['defect']
RELATIVE_MASS_EXCESS = Dimensionless("relative_mass_excess")
RELATIVE_MASS_DEFECT = Dimensionless("relative_mass_defect")
PACKING_FRACTION = Dimensionless('packing_fraction')
BINDING_FRACTION = Dimensionless('binding_fraction')
MEAN_LIFE_TIME = DURATION['mean_life_time']
LEVEL_WIDTH = ENERGY['level_width']
ALPHA_DISINTEGRATION_ENERGY = ENERGY["alpha_disintegration"]
MAXIMUM_BETA_PARTICLE_ENERGY = ENERGY['max_beta_particle']
BETA_DISINTEGRATION_ENERGY = ENERGY['beta_disintegration']
INTERNAL_CONVERSION_FACTOR = Dimensionless(
"internal_conversion_factor"
)
Ratio of electron to gamma ray emissions.
REACTION_ENERGY = ENERGY['reaction']
In a nuclear reaction, sum of kinetic and photon energies of the products minus the energies of the reactants.
CROSS_SECTION = AREA['cross_section_atomic']
Measure of probability that a specific process will take place in a collision of two particles.
TOTAL_CROSS_SECTION = CROSS_SECTION['total']
DIRECTION_DISTRIBUTION_OF_CROSS_SECTION = QtyKind(
M**2 * SR**-1,
("direction_distribution_of_cross_section",),
)
ENERGY_DISTRIBUTION_OF_CROSS_SECTION = QtyKind(
M**2 * J**-1,
("energy_distribution_of_cross_section",),
)
DIRECTION_AND_ENERGY_DISTRIBUTION_OF_CROSS_SECTION = QtyKind(
M**2 * J**-1 * SR**-1,
("direction_and_energy_distribution_of_cross_section",),
)
TOTAL_IONIZATION = Dimensionless('total_ionization')
Mean number of elementary charges of all ions produced by an ionizing, charged particle along its entire path.
AVERAGE_ENERGY_LOSS_PER_ELEMENTARY_CHARGE_PRODUCED = ENERGY[
"average_energy_loss_per_elementary_charge_produced"
]
PARTICLE_NUMBER_DENSITY = NUMBER_DENSITY['particle']
ION_NUMBER_DENSITY = NUMBER_DENSITY['ion']
Measure for the recombination rate of ions.
DIFFUSION_COEFFICIENT_PARTICLE_NUMBER_DENSITY = QtyKind(
M**2 * S**-1,
("diffusion_coefficient_particle_number_density",),
)
RESONANCE_ESCAPE_PROBABILITY = Dimensionless(
"resonance_escape_probability"
)
Probability that a high-energy neutron is not captured.
LETHARGY = Dimensionless('lethargy')
AVERAGE_LOGARITHMIC_ENERGY_DECREMENT = Dimensionless(
"average_logarithmic_energy_decrement"
)
MEAN_FREE_PATH_ATOMIC = MEAN_FREE_PATH['atomic']
MIGRATION_AREA = AREA['migration']
Sum of the slowing-down area of neutrons from fission to thermal energy and the diffusion area of thermal neutrons.
SLOWING_DOWN_LENGTH = LENGTH['slowing_down']
DIFFUSION_LENGTH_ATOMIC = LENGTH['diffusion_atomic']
MIGRATION_LENGTH = LENGTH['migration']
NEUTRON_YIELD_PER_FISSION = Dimensionless(
"neutron_yield_per_fission"
)
Average number of fission neutrons emitted per fission event.
NEUTRON_YIELD_PER_ABSORPTION = Dimensionless(
"neutron_yield_per_absorption"
)
Average number of fission neutrons emitted per absorbed neutron.
FAST_FISSION_FACTOR = Dimensionless('fast_fission_factor')
THERMAL_UTILIZATION_FACTOR = Dimensionless(
"thermal_utilization_factor"
)
NON_LEAKAGE_PROBABILITY = Dimensionless(
"non_leakage_probability"
)
Probability, that a neutron won't escape a reactor while slowing down or while diffusing as thermal neutron.
MULTIPLICATION_FACTOR = Dimensionless(
"multiplication_factor"
)
INFINITE_MULTIPLICATION_FACTOR = Dimensionless(
"infinite_multiplication_factor"
)
In nuclear physics, the multiplication factor for an infinite medium.
REACTOR_TIME_CONSTANT = DURATION['reactor_time_constant']
Duration, in which the neutron fluence rate in a reactor changes by a factor e.
ENERGY_IMPARTED = ENERGY['imparted']
MEAN_ENERGY_IMPARTED = ENERGY['mean_imparted']
In nuclear physics, expectation value of the energy imparted.
IONIZING_QUALITY_FACTOR = Dimensionless(
"quality_factor_ionizing"
)
Factor taking into account health effects in the determination of the dose equivalent.
REYNOLDS_NUMBER = Dimensionless('reynolds_number')
Dimensionless quantity that is used to help predict similar flow patterns in different fluid flow situations.
EULER_NUMBER = Dimensionless('euler_number')
Dimensionless caracteristic number used in fluid mechanics, defined as the ratio of pressure forces and inertial forces used to characterize losses in a moving fluid.
FROUDE_NUMBER = Dimensionless('froude_number')
Dimensionless number defined as the ratio of the flow inertia to the external field.
GRASHOF_NUMBER = Dimensionless('grashof_number')
Characteristic number in fluid dynamics.
WEBER_NUMBER = Dimensionless('weber_number')
Dimensionless number in fluid mechanics that is often useful in analysing fluid flows where there is an interface between two different fluids.
MACH_NUMBER = Dimensionless('mach_number')
KNUDSEN_NUMBER = Dimensionless('knudsen_number')
STROUHAL_NUMBER = Dimensionless('strouhal_number')
BAGNOLD_NUMBER = Dimensionless('bagnold_number')
For a body moving in a fluid the quotient of drag and gravitational force.
BAGNOLD_NUMBER_SOLID_PARTICLES = Dimensionless(
"bagnold_number_solid_particles"
)
LIFT_COEFFICIENT = Dimensionless('lift_coefficient')
THRUST_COEFFICIENT = Dimensionless('thrust_coefficient')
Characteristic number of a propeller.
DEAN_NUMBER = Dimensionless('dean_number')
Characteristic number of flows in curved pipes.
BEJAN_NUMBER = Dimensionless('bejan_number')
Dimensionless pressure drop along a channel.
LAGRANGE_NUMBER = Dimensionless('lagrange_number')
Characteristic number for a fluid in a pipe.
BINGHAM_NUMBER = Dimensionless('bingham_number')
HEDSTROM_NUMBER = Dimensionless('hedstrom_number')
BODENSTEIN_NUMBER = Dimensionless('bodenstein_number')
ROSSBY_NUMBER = Dimensionless('rossby_number')
EKMAN_NUMBER = Dimensionless('ekman_number')
Dimensionless ratio of viscous to Coriolis forces.
ELASTICITY_NUMBER = Dimensionless('elasticity_number')
Characteristic number of viscoelastic flows.
DARCY_FRICTION_FACTOR = Dimensionless(
"darcy_friction_factor"
)
Characteristic number for the pressure drop in a pipe due to friction in a laminar or turbulent flow.
FANNING_NUMBER = Dimensionless('fanning_friction_factor')
Characteristic number for the friction on the wall of a fluid in a pipe.
GOERTLER_NUMBER = Dimensionless('goertler_number')
HAGEN_NUMBER = Dimensionless('hagen_number')
Dimensionless number used in forced flow calculations.
LAVAL_NUMBER = Dimensionless('laval_number')
POISEUILLE_NUMBER = Dimensionless('poiseuille_number')
Characteristic number of flows in a pipe.
POWER_NUMBER = Dimensionless('power_number')
RICHARDSON_NUMBER = Dimensionless('richardson_number')
REECH_NUMBER = Dimensionless('reech_number')
Characteristic number of an object moving in water.
BOUSSINESQ_NUMBER = Dimensionless('boussinesq_number')
See: https://en.wikipedia.org/wiki/Boussinesq_approximation_(buoyancy)
STOKES_NUMBER = Dimensionless('stokes_number')
Characteristic number for particles in a fluid or plasma.
STOKES_NUMBER_VIBRATING_PARTICLES = Dimensionless(
"stokes_number_vibrating_particles"
)
Characteristic number for particles vibrating in a fluid or plasma.
STOKES_NUMBER_ROTAMETER = Dimensionless(
"stokes_number_rotameter"
)
Characteristic number for the calibration of rotameters.
STOKES_NUMBER_GRAVITY = Dimensionless(
"stokes_number_gravity"
)
Characteristic number for particles falling in a fluid.
STOKES_NUMBER_DRAG = Dimensionless('stokes_number_drag')
Characteristic number for particles dragged in a fluid.
LAPLACE_NUMBER = Dimensionless('laplace_number')
Characteristic number in fluid dynamics.
BLAKE_NUMBER = Dimensionless('blake_number')
SOMMERFELD_NUMBER = Dimensionless('sommerfeld_number')
Characteristic number of hydrodynamic bearings.
TAYLOR_NUMBER = Dimensionless('taylor_number')
Characteristic number of a shaft rotating in a fluid.
GALILEI_NUMBER = Dimensionless('galilei_number')
Characteristic number of fluid films flowing over walls.
WOMERSLEY_NUMBER = Dimensionless('womersley_number')
Characteristic number of pulsating flows in a pipe.
FOURIER_NUMBER = Dimensionless('fourier_number')
PECLET_NUMBER = Dimensionless('peclet_number')
Dimensionless ratio used in fluid dynamics.
RAYLEIGH_NUMBER = Dimensionless('rayleigh_number')
FROUDE_NUMBER_HEAT_TRANSFER = Dimensionless(
"froude_number_heat_transfer"
)
NUSSELT_NUMBER = Dimensionless('nusselt_number')
BIOT_NUMBER = Dimensionless('biot_number')
STANTON_NUMBER = Dimensionless('stanton_number')
J_FACTOR_HEAT_TRANSFER = Dimensionless(
"j_factor_heat_transfer"
)
BEJAN_NUMBER_HEAT_TRANSFER = Dimensionless(
"bejan_number_heat_transfer"
)
BEJAN_NUMBER_ENTROPY = Dimensionless("bejan_number_entropy")
STEFAN_NUMBER = Dimensionless('stefan_number')
Characteristic number for the relation between heat and latent heat of a binary mixture undergoing a phase transition.
BRINKMAN_NUMBER = Dimensionless('brinkman_number')
CLAUSIUS_NUMBER = Dimensionless('clausius_number')
ECKERT_NUMBER = Dimensionless('eckert_number')
GRAETZ_NUMBER = Dimensionless('graetz_number')
HEAT_TRANSFER_NUMBER = Dimensionless("heat_transfer_number")
POMERANTSEV_NUMBER = Dimensionless('pomerantsev_number')
Characteristic number for the relation between heat generation and conduction in a body.
BOLTZMANN_NUMBER = Dimensionless('boltzmann_number')
STARK_NUMBER = Dimensionless('stark_number')
Characteristic number for the relation between radiant and conductive heat of a body.
FOURIER_NUMBER_MASS_TRANSFER = Dimensionless(
"fourier_number_mass_transfer"
)
PECLET_NUMBER_MASS_TRANSFER = Dimensionless(
"peclet_number_mass_transfer"
)
GRASHOF_NUMBER_MASS_TRANSFER = Dimensionless(
"grashof_number_mass_transfer"
)
Characteristic number for the relation between buoyancy and viscosity in convection of fluids.
NUSSELT_NUMBER_MASS_TRANSFER = Dimensionless(
"nusselt_number_mass_transfer"
)
Characteristic number for mass transfer at the boundary of a fluid.
STANTON_NUMBER_MASS_TRANSFER = Dimensionless(
"stanton_number_mass_transfer"
)
GRAETZ_NUMBER_MASS_TRANSFER = Dimensionless(
"graetz_number_mass_transfer"
)
J_FACTOR_MASS_TRANSFER = Dimensionless(
"j_factor_mass_transfer"
)
Characteristic number for the relation between mass transport perpendicular and parallel to the surface of an open fluid flow.
ATWOOD_NUMBER = Dimensionless('atwood_number')
BIOT_NUMBER_MASS_TRANSFER = Dimensionless(
"biot_number_mass_transfer"
)
Characteristic number for the relation between mass transfer rate at the interface and in the interior of a body.
MORTON_NUMBER = Dimensionless('morton_number')
Characteristic number for bubbles or drops in a liquid or gas, respectively, under the influence of gravitational an viscous forces.
BOND_NUMBER = Dimensionless('bond_number')
Characteristic number in fluid dynamics.
ARCHIMEDES_NUMBER = Dimensionless('archimedes_number')
EXPANSION_NUMBER = Dimensionless('expansion_number')
Characteristic number for the relation of buoyancy and internal force for gas bubbles rising in a liquid.
MARANGONI_NUMBER = Dimensionless('marangoni_number')
Concept in fluid dynamics.
LOCKHART_MARTINELLI_PARAMETER = Dimensionless(
"lockhart_martinelli_parameter"
)
Characteristic number used in two-phase flow calculations.
BEJAN_NUMBER_MASS_TRANSFER = Dimensionless(
"bejan_number_mass_transfer"
)
Characteristic number for viscous flows in pipes.
CAVITATION_NUMBER = Dimensionless('cavitation_number')
Concept in fluid mechanics.
ABSORPTION_NUMBER = Dimensionless('absorption_number')
Characteristic number for the absorption of gas at a wet surface.
CAPILLARY_NUMBER = Dimensionless('capillary_number')
Quotient of gravitational and capillary forces for fluids in narrow pipes.
DYNAMIC_CAPILLARY_NUMBER = Dimensionless(
"dynamic_capillary_number"
)
Ratio of viscous drag forces to surface tension in fluids.
PRANDTL_NUMBER = Dimensionless('prandtl_number')
SCHMIDT_NUMBER = Dimensionless('schmidt_number')
LEWIS_NUMBER = Dimensionless('lewis_number')
OHNESORGE_NUMBER = Dimensionless('ohnesorge_number')
Characteristic number that relates the viscous forces to inertial and surface tension forces.
CAUCHY_NUMBER = Dimensionless('cauchy_number')
Characteristic number in continuum mechanics used in the study of compressible flows.
HOOKE_NUMBER = Dimensionless('hooke_number')
Characteristic number for elastic fluids.
WEISSENBERG_NUMBER = Dimensionless('weissenberg_number')
DEBORAH_NUMBER = Dimensionless('deborah_number')
LORENTZ_NUMBER = Dimensionless('lorentz_number')
COMPRESSIBILITY_NUMBER = Dimensionless(
"compressibility_number"
)
Correction factor which describes the deviation of a real gas from ideal gas behavior.
REYNOLDS_MAGNETIC_NUMBER = Dimensionless(
"reynolds_magnetic_number"
)
Characteristic number of an electrically conducting fluid.
BATCHELOR_NUMBER = Dimensionless('batchelor_number')
Characteristic number of an electrically conducting liquid.
NUSSELT_ELECTRIC_NUMBER = Dimensionless(
"nusselt_electric_number"
)
Characteristic number for the relation between convective and diffusive ion current.
ALFVEN_NUMBER = Dimensionless('alfven_number')
HARTMANN_NUMBER = Dimensionless('hartmann_number')
Characteristic number for electrically conducting fluids.
COWLING_NUMBER = Dimensionless('cowling_number')
STUART_ELECTRICAL_NUMBER = Dimensionless(
"stuart_electrical_number"
)
Characteristic number for the relation of electric to kinematic energy in a plasma.
MAGNETIC_PRESSURE_NUMBER = Dimensionless(
"magnetic_pressure_number"
)
Quotient of gas and magnetic pressure in a gas or plasma.
CHANDRASEKHAR_NUMBER = Dimensionless("chandrasekhar_number")
PRANDTL_MAGNETIC_NUMBER = Dimensionless(
"prandtl_magnetic_number"
)
ROBERTS_NUMBER = Dimensionless('roberts_number')
STUART_NUMBER = Dimensionless('stuart_number')
MAGNETIC_NUMBER = Dimensionless('magnetic_number')
Quotient of magnetic and viscous forces in an electrically conducting fluid.
ELECTRIC_FIELD_PARAMETER = Dimensionless(
"electric_field_parameter"
)
Quotient of Coulomb and Lorentz force on moving, electrically charged particles.
HALL_NUMBER = Dimensionless('hall_number')
Quotient of gyro and collision frequency in a plasma.
LUNDQUIST_NUMBER = Dimensionless('lundquist_number')
JOULE_MAGNETIC_NUMBER = Dimensionless(
"joule_magnetic_number"
)
GRASHOF_MAGNETIC_NUMBER = Dimensionless(
"grashof_magnetic_number"
)
Characteristic number for the heat transfer by thermo-magnetic convection of a paramagnetic fluid under the influence of gravity.
NAZE_NUMBER = Dimensionless('naze_number')
Quotient of Alfvén wave speed and sound speed in a plasma.
REYNOLDS_ELECTRIC_NUMBER = Dimensionless(
"reynolds_electric_number"
)
Quotient of the speed of an electrically conducting fluid and drift speed of its charged particles.
AMPERE_NUMBER = Dimensionless('ampere_number')
Characteristic number for the relation between electric surface current and magnetic field strength in an electrically conducting liquid.
ARRHENIUS_NUMBER = Dimensionless('arrhenius_number')
LANDAU_GINZBURG_NUMBER = Dimensionless(
"landau_ginzburg_number"
)
Characteristic number of a superconductor.
Translation vector which maps a crystal lattice onto itself.
FUNDAMENTAL_LATTICE_VECTORS = LATTICE_VECTOR['fundamental']
Fundamental translation vector for a crystal lattice.
Vector whose scalar product with a fundamental lattice vector is an integral multiple of two Pi.
FUNDAMENTAL_RECIPROCAL_LATTICE_VECTORS = (
ANGULAR_RECIPROCAL_LATTICE_VECTOR["fundamental"]
)
Fundamental translation vector for a reciprocal lattice.
Distance between adjacent lattice planes.
BRAGG_ANGLE = ANGLE['bragg']
In X-ray crystallography, angle between lattice plane and scattered ray.
SHORT_RANGE_ORDER_PARAMETER = Dimensionless(
"short_range_order_parameter"
)
LONG_RANGE_ORDER_PARAMETER = Dimensionless(
"long_range_order_parameter"
)
ATOMIC_SCATTERING_FACTOR = Dimensionless(
"atomic_scattering_factor"
)
Measure of the scattering amplitude of a wave by an isolated atom.
STRUCTURE_FACTOR = Dimensionless('structure_factor')
Mathematical description in crystallography.
Vector characterising a dislocation in a crystal lattice.
PARTICLE_POSITION_VECTOR = POSITION['particle']
Position vector of a particle.
EQUILIBRIUM_POSITION_VECTOR = POSITION['equilibrium']
In condensed matter physics, position vector of an atom or ion in equilibrium.
DISPLACEMENT_VECTOR_LATTICE = DISPLACEMENT['lattice']
In condensed matter physics, position vector of an atom or ion relative to its equilibrium position.
DEBYE_WALLER_FACTOR = Dimensionless('debye_waller_factor')
Is used in condensed matter physics to describe the attenuation of x-ray scattering or coherent neutron scattering caused by thermal motion.
ANGULAR_WAVENUMBER_LATTICE = ANGULAR_WAVENUMBER['lattice']
FERMI_ANGULAR_WAVENUMBER = ANGULAR_WAVENUMBER_LATTICE[
"fermi"
]
Angular wavenumber of an electron in a state on the Fermi surface.
DEBYE_ANGULAR_WAVENUMBER = ANGULAR_WAVENUMBER_LATTICE[
"debye"
]
DEBYE_ANGULAR_FREQUENCY = ANGULAR_FREQUENCY['debye']
Quantity in condensed matter physics.
THERMODYNAMIC_GRUNEISEN_PARAMETER = Dimensionless(
"thermodynamic_gruneisen_parameter"
)
GRUNEISEN_PARAMETER = Dimensionless('gruneisen_parameter')
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.
MEAN_FREE_PATH_OF_PHONONS = MEAN_FREE_PATH['phonon']
MEAN_FREE_PATH_OF_ELECTRONS = MEAN_FREE_PATH['electron']
Quantity in condensed matter physics.
RESIDUAL_RESISTIVITY = RESISTIVITY['residual']
Coefficient of proportionality in the Wiedemann-Franz law.
THERMOELECTRIC_VOLTAGE = VOLTAGE['thermoelectric']
Voltage caused by the thermoelectric effect.
ELECTRON_AFFINITY = ENERGY['electron_affinity']
In condensed matter physics, energy difference between an electron at rest at infinity and the lowest level of the conduction band in an insulator or semiconductor.
GAP_ENERGY = ENERGY['gap']
Smallest energy difference between neighboring conduction bands separated by a forbidden band.
ELECTRON_DENSITY = NUMBER_DENSITY['electron']
In condensed matter physics, number of electrons in the conduction band per volume.
HOLE_DENSITY = NUMBER_DENSITY['hole']
In condensed matter physics, number of holes in the valence band per volume.
INTRINSIC_CARRIER_DENSITY = NUMBER_DENSITY[
"intrinsic_carrier"
]
DONOR_DENSITY = NUMBER_DENSITY['donor']
Number of donor levels per volume.
ACCEPTOR_DENSITY = NUMBER_DENSITY['acceptor']
Number of acceptor levels per volume.
EFFECTIVE_MASS = MASS['effective']
MOBILITY_RATIO = Dimensionless('mobility_ratio')
RELAXATION_TIME_LATTICE = DURATION['relaxation_lattice']
In condensed matter physics, time constant for interactions (scattering, annihilation, etc.) of charge carriers or quasiparticles (phonons, etc.).
DIFFUSION_LENGTH = LENGTH['diffusion']
In condensed matter physics, the square root of the product of diffusion coefficient and lifetime.
EXCHANGE_INTEGRAL = ENERGY['exchange_integral']
CURIE_TEMPERATURE = TEMPERATURE['curie']
Temperature above which certain materials lose their permanent magnetic properties.
NEEL_TEMPERATURE = TEMPERATURE['neel']
Critical temperature of an antiferromagnet.
SUPERCONDUCTION_TRANSITION_TEMPERATURE = TEMPERATURE[
"superconduction_transition"
]
Critical temperature of a superconductor.
THERMODYNAMIC_CRITICAL_MAGNETIC_FLUX_DENSITY = (
MAGNETIC_FLUX_DENSITY["critical", "thermodynamic"]
)
LOWER_CRITICAL_MAGNETIC_FLUX_DENSITY = (
MAGNETIC_FLUX_DENSITY["critical", "lower"]
)
UPPER_CRITICAL_MAGNETIC_FLUX_DENSITY = (
MAGNETIC_FLUX_DENSITY["critical", "upper"]
)
SUPERCONDUCTOR_ENERGY_GAP = ENERGY['superconductor_gap']
Width of the forbidden energy band in a superconductor.
LONDON_PENETRATION_DEPTH = LENGTH[
"london_penetration_depth"
]
ERLANG = Dimensionless('erlang')
Erlang, a dimensionless unit for telephone traffic intensity.
TRAFFIC_INTENSITY = Dimensionless('traffic_intensity')
TRAFFIC_OFFERED_INTENSITY = Dimensionless(
"traffic_offered_intensity"
)
TRAFFIC_CARRIED_INTENSITY = Dimensionless(
"traffic_carried_intensity"
)
MEAN_QUEUE_LENGTH = Dimensionless('mean_queue_length')
Time average of the length of a queue.
LOSS_PROBABILITY = Dimensionless('loss_probability')
Probability for losing a call attempt.
WAITING_PROBABILITY = Dimensionless('waiting_probability')
Probability for waiting for a resource.
Completed calls per time.
STORAGE_CAPACITY = Dimensionless('storage_capacity')
PERIOD_OF_DATA_ELEMENTS = PERIOD['data_elements']
Information transmission rate expressed in bits per second.
BIT_PERIOD = PERIOD['bit']
BAUD = (S**-1)["modulation_rate"].alias(
"baud", allow_prefix=True
)
Baud, a unit of modulation rate (symbol rate).
SIGNAL_ENERGY_PER_BINARY_DIGIT = ENERGY[
"signal_per_binary_digit"
]
ERROR_PROBABILITY = Dimensionless('error_probability')
Probability for incorrectly receiving a data element.
HAMMING_DISTANCE = Dimensionless('hamming_distance')
Number of bits that differ between two strings.
DECISION_CONTENT = Dimensionless('decision_content')
SHANNON = Log(PROBABILITY_RATIO, base=2).alias('shannon')
Logarithmic level of information (base 2).
HARTLEY = Log(PROBABILITY_RATIO, base=10).alias('hartley')
Logarithmic level of information (base 10), also known as a ban or dit.
Logarithmic quantity derived from the probability of a particular event.
RELATIVE_ENTROPY = Dimensionless('relative_entropy')
In information theory, extra bits transmitted without adding information.
RELATIVE_REDUNDANCY = Dimensionless('relative_redundancy')
JOINT_INFORMATION_CONTENT = INFORMATION_CONTENT['joint']
CONDITIONAL_INFORMATION_CONTENT = INFORMATION_CONTENT[
"conditional"
]
CONDITIONAL_ENTROPY = ENTROPY['conditional']
Measure of relative information in probability theory and information theory.
EQUIVOCATION = CONDITIONAL_ENTROPY['equivocation']
Concept in information theory: the information that is lost during transmission over a channel between an information source (sender) and an information sink (receiver).
IRRELEVANCE = CONDITIONAL_ENTROPY['irrelevance']
TRANSINFORMATION_CONTENT = INFORMATION_CONTENT[
"transinformation"
]
Measure of dependence between two variables.
CHARACTER_MEAN_TRANSINFORMATION_CONTENT = QtyKind(
SHANNON, ("character_mean_transinformation_content",)
)