"""Chemical Engineering Design Library (ChEDL). Utilities for process modeling.
Copyright (C) 2016, 2017, 2018, 2019, 2020 Caleb Bell
<Caleb.Andrew.Bell@gmail.com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
This module contains various refractive index lookup, calculation,
and unit conversion routines and dataframes.
For reporting bugs, adding feature requests, or submitting pull requests,
please use the `GitHub issue tracker <https://github.com/CalebBell/chemicals/>`_.
.. contents:: :local:
Lookup Functions
----------------
.. autofunction:: chemicals.refractivity.RI
.. autofunction:: chemicals.refractivity.RI_methods
.. autodata:: chemicals.refractivity.RI_all_methods
Correlations for Specific Substances
------------------------------------
.. autofunction:: chemicals.refractivity.RI_IAPWS
Unit Conversions
----------------
.. autofunction:: chemicals.refractivity.brix_to_RI
.. autofunction:: chemicals.refractivity.RI_to_brix
Utility functions
-----------------
.. autofunction:: chemicals.refractivity.polarizability_from_RI
.. autofunction:: chemicals.refractivity.molar_refractivity_from_RI
.. autofunction:: chemicals.refractivity.RI_from_molar_refractivity
Pure Component Liquid Fit Correlations
--------------------------------------
.. autofunction:: chemicals.refractivity.TDE_RIXExpansion
"""
__all__ = ['RI', 'RI_methods', 'RI_all_methods',
'polarizability_from_RI', 'molar_refractivity_from_RI',
'RI_from_molar_refractivity', 'RI_IAPWS', 'RI_to_brix',
'brix_to_RI', 'TDE_RIXExpansion']
from fluids.constants import N_A, pi
from fluids.numerics import horner, interp, isnan, sqrt
from chemicals import data_reader as dr
from chemicals import miscdata
from chemicals.data_reader import (
data_source,
database_constant_lookup,
list_available_methods_from_df_dict,
register_df_source,
retrieve_any_from_df_dict,
retrieve_from_df_dict,
)
from chemicals.utils import PY37, can_load_data, mark_numba_incompatible, os_path_join, source_path
# Register data sources and lazy load them
folder = os_path_join(source_path, 'Misc')
register_df_source(folder, 'CRC Handbook Organic RI.csv',
csv_kwargs={'dtype': {'RI': float, 'RIT': float}})
CRC = 'CRC'
_RI_data_loaded = False
@mark_numba_incompatible
def _load_RI_data():
global _RI_data_loaded, RI_data_CRC_organic, RI_sources
RI_data_CRC_organic = data_source('CRC Handbook Organic RI.csv')
RI_sources = {
CRC: RI_data_CRC_organic,
miscdata.WIKIDATA: miscdata.wikidata_data
}
if PY37:
def __getattr__(name):
if name in ('RI_data_CRC_organic', 'RI_sources'):
_load_RI_data()
return globals()[name]
raise AttributeError(f"module {__name__} has no attribute {name}")
else:
if can_load_data:
_load_RI_data()
# Refractive index functions
RI_all_methods = (CRC, miscdata.WIKIDATA)
"""Tuple of method name keys. See the `RI` for the actual references"""
[docs]@mark_numba_incompatible
def RI_methods(CASRN):
"""Return all methods available to obtain the refractive index for the
desired chemical.
Parameters
----------
CASRN : str
CASRN, [-]
Returns
-------
methods : list[str]
Methods which can be used to obtain the RI with the given
inputs.
See Also
--------
RI
"""
if not _RI_data_loaded: _load_RI_data()
return list_available_methods_from_df_dict(RI_sources, CASRN, 'RI')
[docs]@mark_numba_incompatible
def RI(CASRN, method=None):
r'''This function handles the retrieval of a chemical's refractive
index. Lookup is based on CASRNs. Will automatically select a data source
to use if no method is provided; returns None if the data is not available.
Function has data for approximately 4500 chemicals.
Parameters
----------
CASRN : str
CASRN [-]
Returns
-------
RI : float
Refractive Index on the Na D line, [-]
T : float or None
Temperature at which refractive index reading was made; None if not
available, [K]
Other Parameters
----------------
method : string, optional
A string for the method name to use, as defined by constants in
RI_methods
Notes
-----
The available sources are as follows:
* 'CRC', a compillation of Organic RI data in [1]_.
* 'WIKIDATA', data from the Wikidata project [2]_
Examples
--------
>>> RI(CASRN='64-17-5')
(1.3611, 293.15)
>>> RI("60-35-5")
(1.4278, None)
>>> RI('100-41-4', method='WIKIDATA')
(1.495, None)
References
----------
.. [1] Haynes, W.M., Thomas J. Bruno, and David R. Lide. CRC Handbook of
Chemistry and Physics, 95E. Boca Raton, FL: CRC press, 2014.
.. [2] Wikidata. Wikidata. Accessed via API. https://www.wikidata.org/
'''
if dr.USE_CONSTANTS_DATABASE and method is None:
RI, found = database_constant_lookup(CASRN, 'RI')
RIT, _ = database_constant_lookup(CASRN, 'RIT')
if found: return (RI, RIT)
if not _RI_data_loaded: _load_RI_data()
key = ('RI', 'RIT')
if method:
value = retrieve_from_df_dict(RI_sources, CASRN, key, method)
else:
value = retrieve_any_from_df_dict(RI_sources, CASRN, key)
if value is None:
value = (None, None)
else:
if isnan(value[0]):
value = (None, None)
elif isnan(value[1]):
value = (value[0], None)
else:
value = tuple(value)
return value
[docs]def polarizability_from_RI(RI, Vm):
r'''Returns the polarizability of a fluid given its molar volume and
refractive index.
.. math::
\alpha = \left(\frac{3}{4\pi N_A}\right)
\left(\frac{n^2-1}{n^2+2}\right)V_m
Parameters
----------
RI : float
Refractive Index on Na D line, [-]
Vm : float
Molar volume of fluid, [m^3/mol]
Returns
-------
alpha : float
Polarizability [m^3]
Notes
-----
This Lorentz-Lorentz-expression is most correct when van der Waals
interactions dominate. Alternate conversions have been suggested.
This is often expressed in units of cm^3 or Angstrom^3. To convert to these
units, multiply by 1E9 or 1E30 respectively.
Examples
--------
>>> polarizability_from_RI(1.3611, 5.8676E-5)
5.147658206528923e-30
References
----------
.. [1] Panuganti, Sai R., Fei Wang, Walter G. Chapman, and Francisco M.
Vargas. "A Simple Method for Estimation of Dielectric Constants and
Polarizabilities of Nonpolar and Slightly Polar Hydrocarbons."
International Journal of Thermophysics 37, no. 7 (June 6, 2016): 1-24.
doi:10.1007/s10765-016-2075-8.
'''
return 3/(4*pi*N_A)*(RI**2-1)/(RI**2+2)*Vm
[docs]def molar_refractivity_from_RI(RI, Vm):
r'''Returns the molar refractivity of a fluid given its molar volume and
refractive index.
.. math::
R_m = \left(\frac{n^2-1}{n^2+2}\right)V_m
Parameters
----------
RI : float
Refractive Index on Na D line, [-]
Vm : float
Molar volume of fluid, [m^3/mol]
Returns
-------
Rm : float
Molar refractivity [m^3/mol]
Notes
-----
Examples
--------
>>> molar_refractivity_from_RI(1.3611, 5.8676E-5)
1.2985217089649597e-05
References
----------
.. [1] Panuganti, Sai R., Fei Wang, Walter G. Chapman, and Francisco M.
Vargas. "A Simple Method for Estimation of Dielectric Constants and
Polarizabilities of Nonpolar and Slightly Polar Hydrocarbons."
International Journal of Thermophysics 37, no. 7 (June 6, 2016): 1-24.
doi:10.1007/s10765-016-2075-8.
'''
return (RI**2 - 1.)/(RI**2 + 2.)*Vm
[docs]def RI_from_molar_refractivity(Rm, Vm):
r'''Returns the refractive index of a fluid given its molar volume and
molar refractivity.
.. math::
RI = \sqrt{\frac{-2R_m - V_m}{R_m-V_m}}
Parameters
----------
Rm : float
Molar refractivity [m^3/mol]
Vm : float
Molar volume of fluid, [m^3/mol]
Returns
-------
RI : float
Refractive Index on Na D line, [-]
Notes
-----
Examples
--------
>>> RI_from_molar_refractivity(1.2985e-5, 5.8676E-5)
1.3610932757685672
References
----------
.. [1] Panuganti, Sai R., Fei Wang, Walter G. Chapman, and Francisco M.
Vargas. "A Simple Method for Estimation of Dielectric Constants and
Polarizabilities of Nonpolar and Slightly Polar Hydrocarbons."
International Journal of Thermophysics 37, no. 7 (June 6, 2016): 1-24.
doi:10.1007/s10765-016-2075-8.
'''
Rm = ((-2*Rm - Vm)/(Rm-Vm))**0.5
return Rm
[docs]def RI_IAPWS(T, rho, wavelength=0.5893e-6):
r'''Calculates the refractive index of water at a given temperature,
density, and wavelength.
.. math::
n(\rho, T, \lambda) = \left(\frac{2A + 1}{1-A}\right)^{0.5}
.. math::
A(\delta, \theta, \Lambda) = \delta\left(a_0 + a_1\delta +
a_2\theta + a_3\Lambda^2\theta + a_4\Lambda^{-2}
\frac{a_5}{\Lambda^2-\Lambda_{UV}^2} + \frac{a_6}
{\Lambda^2 - \Lambda_{IR}^2} + a_7\delta^2\right)
.. math::
\delta = \rho/(1000 \text{ kg/m}^3)
.. math::
\theta = T/273.15\text{K}
.. math::
\Lambda = \lambda/0.589 \mu m
.. math::
\Lambda_{IR} = 5.432937
.. math::
\Lambda_{UV} = 0.229202
Parameters
----------
T : float
Temperature of the water [K]
rho : float
Density of the water [kg/m^3]
wavelength : float
Wavelength of fluid [meters]
Returns
-------
RI : float
Refractive index of the water, [-]
Notes
-----
This function is valid in the following range:
261.15 K < T < 773.15 K
0 < rho < 1060 kg/m^3
0.2 < wavelength < 1.1 micrometers
Test values are from IAPWS 2010 book.
Examples
--------
>>> RI_IAPWS(298.15, 997.047435)
1.3328581926471605
References
----------
.. [1] IAPWS, 1997. Release on the Refractive Index of Ordinary Water
Substance as a Function of Wavelength, Temperature and Pressure.
'''
wavelength *= 1e6
delta = rho*1e-3
theta = T*(1.0/273.15)
Lambda = wavelength*(1.0/0.589)
LambdaIR = 5.432937
LambdaUV = 0.229202
Lambda2 = Lambda*Lambda
A = delta*(0.244257733 + 0.0097463448*delta + -0.00373235*theta + 0.0002686785*Lambda2*theta +
0.0015892057/Lambda2 + 0.0024593426/(Lambda2 - LambdaUV*LambdaUV) +
0.90070492/(Lambda2 - LambdaIR*LambdaIR) - 0.0166626219*delta*delta)
n = sqrt((2.0*A + 1.)/(1. - A))
return n
[docs]def TDE_RIXExpansion(T, Bs, Cs, wavelength=589.26e-9):
r'''Calculates the refractive index of a pure liquid at a given temperature,
and wavelength, using the NIST TDE RIXExpansion formula [1]_.
.. math::
n(T, \lambda) = \sum_{i=0}^{i} B_i t^i + \sum_j C_j w^j
.. math::
t = T - 298.15
.. math::
w = WL\times 10^{9} - 589.26
Parameters
----------
T : float
Temperature of the fluid [K]
Bs : list[float]
Polynomial temperature expansion coefficients, in reverse order to the
polynomial (as needed for efficient computation with horner's method'),
[-]
Cs : list[float]
Polynomial wavelength expansion coefficients, in reverse order to the
polynomial (as needed for efficient computation with horner's method'),
[-]
wavelength : float
Wavelength of fluid [meters]
Returns
-------
RI : float
Refractive index of the pure fluid, [-]
Notes
-----
Examples
--------
>>> TDE_RIXExpansion(330.0, Bs=[-0.000125041, 1.33245], Cs=[1.20771e-7, -3.56795e-5, 0.0], wavelength=589.26e-9*.7)
1.33854894426073
References
----------
.. [1] "ThermoData Engine (TDE103b V10.1) User`s Guide."
https://trc.nist.gov/TDE/Help/TDE103b/Eqns-Pure-RefractiveIndex/RIXExpansion.htm.
'''
t = T - 298.15
w = (wavelength - 589.26e-9)*1e9
n_D = horner(Bs, t)
if Cs is not None:
n_D += horner(Cs, w)
return n_D
ICUMSA_1974_brix = [float(i) for i in range(96)]
ICUMSA_1974_RIs = [1.33299, 1.33442, 1.33586, 1.33732, 1.33879, 1.34026, 1.34175,
1.34325, 1.34477, 1.34629, 1.34782, 1.34937, 1.35093, 1.35250,
1.35408, 1.35568, 1.35729, 1.35891, 1.36054, 1.36218, 1.36384,
1.36551, 1.36720, 1.36889, 1.37060, 1.37233, 1.37406, 1.37582,
1.37758, 1.37936, 1.38115, 1.38296, 1.38478, 1.38661, 1.38846,
1.39032, 1.39220, 1.39409, 1.39600, 1.39792, 1.39986, 1.40181,
1.40378, 1.40576, 1.40776, 1.40978, 1.41181, 1.41385, 1.41592,
1.41799, 1.42009, 1.42220, 1.42432, 1.42647, 1.42863, 1.43080,
1.43299, 1.43520, 1.43743, 1.43967, 1.44193, 1.44420, 1.44650,
1.44881, 1.45113, 1.45348, 1.45584, 1.45822, 1.46061, 1.46303,
1.46546, 1.46790, 1.47037, 1.47285, 1.47535, 1.47787, 1.48040,
1.48295, 1.48552, 1.48811, 1.49071, 1.49333, 1.49597, 1.49862,
1.50129, 1.50398, 1.5067, 1.5094, 1.5122, 1.5149, 1.5177,
1.5205, 1.5234, 1.5262, 1.5291, 1.5320]
[docs]def brix_to_RI(brix):
"""Convert a refractive index measurement on the `brix` scale to a standard
refractive index.
Parameters
----------
brix : float
Degrees brix to be converted, [°Bx]
Returns
-------
RI : float
Refractive index, [-]
Notes
-----
The scale is officially defined from 0 to 85; but the data source contains
values up to 95. Linear extrapolation outside of the bounds is performed;
and a table of 96 values are linearly interpolated.
The ICUMSA (International Committee of Uniform Method of Sugar Analysis)
published a document setting out the reference values in 1974; but an
original data source has not been found and reviewed.
Examples
--------
>>> brix_to_RI(5.8)
1.341452
>>> brix_to_RI(0.0)
1.33299
>>> brix_to_RI(95.0)
1.532
References
----------
.. [1] "Refractometer Data Book-Refractive Index and Brix | ATAGO CO.,
LTD." Accessed June 13, 2020.
https://www.atago.net/en/databook-refractometer_relationship.php.
"""
return interp(brix, ICUMSA_1974_brix, ICUMSA_1974_RIs, extrapolate=True)
[docs]def RI_to_brix(RI):
"""Convert a standard refractive index measurement to the `brix` scale.
Parameters
----------
RI : float
Refractive index, [-]
Returns
-------
brix : float
Degrees brix to be converted, [°Bx]
Notes
-----
The scale is officially defined from 0 to 85; but the data source contains
values up to 95.
Linear extrapolation to values under 0 or above 95 is performed.
The ICUMSA (International Committee of Uniform Method of Sugar Analysis)
published a document setting out the reference values in 1974; but an
original data source has not been found and reviewed.
Examples
--------
>>> RI_to_brix(1.341452)
5.800000000000059
>>> RI_to_brix(1.33299)
0.0
>>> RI_to_brix(1.532)
95.0
References
----------
.. [1] "Refractometer Data Book-Refractive Index and Brix | ATAGO CO.,
LTD." Accessed June 13, 2020.
https://www.atago.net/en/databook-refractometer_relationship.php.
"""
return interp(RI, ICUMSA_1974_RIs, ICUMSA_1974_brix, extrapolate=True)