A new method for multicomponent activity coefficients of electrolytes in aqueous atmospheric aerosols

2005 ◽  
Vol 110 (D2) ◽  
Author(s):  
Rahul A. Zaveri
Keyword(s):  
Activity Coefficients ◽  
Atmospheric Aerosols ◽  
New Method

scholarly journals A new method to retrieve the real part of the equivalent refractive index of atmospheric aerosols

2018 ◽  
Vol 117 ◽  
pp. 54-62 ◽  
Author(s):  
S. Vratolis ◽  
P. Fetfatzis ◽  
A. Argyrouli ◽  
A. Papayannis ◽  
D. Müller ◽  
...  
Keyword(s):  
Refractive Index ◽  
Atmospheric Aerosols ◽  
New Method ◽  
The Real

A new method for estimating dry deposition velocities for atmospheric aerosols

1986 ◽  
Vol 17 (3) ◽  
pp. 240-244 ◽  
Author(s):  
S.K. Friedlander ◽  
J.R. Turner ◽  
S.V. Hering
Keyword(s):  
Atmospheric Aerosols ◽  
Dry Deposition ◽  
New Method ◽  
Deposition Velocities

scholarly journals Method for Estimating Activity Coefficients of Target Components in Poorly Specified Mixtures

2021 ◽  
Author(s):  
Fabian Jirasek ◽  
Jakob Burger ◽  
Hans Hasse
Keyword(s):  
Nmr Spectroscopy ◽  
Activity Coefficient ◽  
Activity Coefficients ◽  
New Method ◽  
Target Component ◽  
Test Cases ◽  
Group Contribution Method ◽  
Bioprocess Engineering ◽  
Separation Processes ◽  
Chemical Groups

Mixtures that contain a known target component but are otherwise poorly specified 15 are important in many fields. Previously, the activity of the target component, which is needed e.g. to design separation processes, could not be predicted in such mixtures. A method was developed to solve this problem. It combines a thermodynamic group contribution method for the activity coefficient with NMR spectroscopy, which is used for estimating the nature and amount of the different chemical groups in the mixture. The knowledge of the component 20 speciation of the mixture is not required. Test cases that are inspired by bioprocess engineering applications show that the new method gives surprisingly good results.

scholarly journals New and extended parameterization of the thermodynamic model AIOMFAC: calculation of activity coefficients for organic-inorganic mixtures containing carboxyl, hydroxyl, carbonyl, ether, ester, alkenyl, alkyl, and aromatic functional groups

2011 ◽  
Vol 11 (17) ◽  
pp. 9155-9206 ◽  
Author(s):  
A. Zuend ◽  
C. Marcolli ◽  
A. M. Booth ◽  
D. M. Lienhard ◽  
V. Soonsin ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Functional Groups ◽  
Organic Compounds ◽  
Activity Coefficients ◽  
Atmospheric Aerosols ◽  
Atmospheric Chemistry ◽  
Inorganic Ions ◽  
Aqueous Mixtures ◽  
Organic Functional Groups ◽  
Ether Ester

Abstract. We present a new and considerably extended parameterization of the thermodynamic activity coefficient model AIOMFAC (Aerosol Inorganic-Organic Mixtures Functional groups Activity Coefficients) at room temperature. AIOMFAC combines a Pitzer-like electrolyte solution model with a UNIFAC-based group-contribution approach and explicitly accounts for interactions between organic functional groups and inorganic ions. Such interactions constitute the salt-effect, may cause liquid-liquid phase separation, and affect the gas-particle partitioning of aerosols. The previous AIOMFAC version was parameterized for alkyl and hydroxyl functional groups of alcohols and polyols. With the goal to describe a wide variety of organic compounds found in atmospheric aerosols, we extend here the parameterization of AIOMFAC to include the functional groups carboxyl, hydroxyl, ketone, aldehyde, ether, ester, alkenyl, alkyl, aromatic carbon-alcohol, and aromatic hydrocarbon. Thermodynamic equilibrium data of organic-inorganic systems from the literature are critically assessed and complemented with new measurements to establish a comprehensive database. The database is used to determine simultaneously the AIOMFAC parameters describing interactions of organic functional groups with the ions H+, Li+, Na+, K+, NH4+, Mg2+, Ca2+, Cl−, Br−, NO3−, HSO4−, and SO42−. Detailed descriptions of different types of thermodynamic data, such as vapor-liquid, solid-liquid, and liquid-liquid equilibria, and their use for the model parameterization are provided. Issues regarding deficiencies of the database, types and uncertainties of experimental data, and limitations of the model, are discussed. The challenging parameter optimization problem is solved with a novel combination of powerful global minimization algorithms. A number of exemplary calculations for systems containing atmospherically relevant aerosol components are shown. Amongst others, we discuss aqueous mixtures of ammonium sulfate with dicarboxylic acids and with levoglucosan. Overall, the new parameterization of AIOMFAC agrees well with a large number of experimental datasets. However, due to various reasons, for certain mixtures important deviations can occur. The new parameterization makes AIOMFAC a versatile thermodynamic tool. It enables the calculation of activity coefficients of thousands of different organic compounds in organic-inorganic mixtures of numerous components. Models based on AIOMFAC can be used to compute deliquescence relative humidities, liquid-liquid phase separations, and gas-particle partitioning of multicomponent mixtures of relevance for atmospheric chemistry or in other scientific fields.

scholarly journals New and extended parameterization of the thermodynamic model AIOMFAC: calculation of activity coefficients for organic-inorganic mixtures containing carboxyl, hydroxyl, carbonyl, ether, ester, alkenyl, alkyl, and aromatic functional groups

2011 ◽  
Vol 11 (5) ◽  
pp. 15297-15416 ◽  
Author(s):  
A. Zuend ◽  
C. Marcolli ◽  
A. M. Booth ◽  
D. M. Lienhard ◽  
V. Soonsin ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Functional Groups ◽  
Organic Compounds ◽  
Activity Coefficients ◽  
Atmospheric Aerosols ◽  
Atmospheric Chemistry ◽  
Inorganic Ions ◽  
Aqueous Mixtures ◽  
Organic Functional Groups ◽  
Ether Ester

Abstract. We present a new and considerably extended parameterization of the thermodynamic activity coefficient model AIOMFAC (Aerosol Inorganic-Organic Mixtures Functional groups Activity Coefficients) at room temperature. AIOMFAC combines a Pitzer-like electrolyte solution model with a UNIFAC-based group-contribution approach and explicitly accounts for interactions between organic functional groups and inorganic ions. Such interactions constitute the salt-effect, may cause liquid-liquid phase separation, and affect the gas-particle partitioning of aerosols. The previous AIOMFAC version was parameterized for alkyl and hydroxyl functional groups of alcohols and polyols. With the goal to describe a wide variety of organic compounds found in atmospheric aerosols, we extend here the parameterization of AIOMFAC to include the functional groups carboxyl, hydroxyl, ketone, aldehyde, ether, ester, alkenyl, alkyl, aromatic carbon-alcohol, and aromatic hydrocarbon. Thermodynamic equilibrium data of organic-inorganic systems from the literature are critically assessed and complemented with new measurements to establish a comprehensive database. The database is used to determine simultaneously the AIOMFAC parameters describing interactions of organic functional groups with the ions H+, Li+, Na+, K+, NH4+, Mg2+, Ca2+, Cl−, Br−, NO3−, HSO4−, and SO42−. Detailed descriptions of different types of thermodynamic data, such as vapor-liquid, solid-liquid, and liquid-liquid equilibria, and their use for the model parameterization are provided. Issues regarding deficiencies of the database, types and uncertainties of experimental data, and limitations of the model, are discussed. The challenging parameter optimization problem is solved with a novel combination of powerful global minimization algorithms. A number of exemplary calculations for systems containing atmospherically relevant aerosol components are shown. Amongst others, we discuss aqueous mixtures of ammonium sulfate with dicarboxylic acids and with levoglucosan. Overall, the new parameterization of AIOMFAC agrees well with a large number of experimental datasets. However, due to various reasons, for certain mixtures important deviations can occur. The new parameterization makes AIOMFAC a versatile thermodynamic tool. It enables the calculation of activity coefficients of thousands of different organic compounds in organic-inorganic mixtures of numerous components. Models based on AIOMFAC can be used to compute deliquescence relative humidities, liquid-liquid phase separations, and gas-particle partitioning of multicomponent mixtures of relevance for atmospheric chemistry or in other scientific fields.

Determining activity coefficients of liquids in binary solutions: A new method

1970 ◽  
Vol 47 (12) ◽  
pp. 826 ◽  
Author(s):  
H. J. Arnikar ◽  
T. S. Rao ◽  
A. A. Bodhe
Keyword(s):  
Activity Coefficients ◽  
New Method ◽  
Binary Solutions

A NEW METHOD FOR THE DETERMINATION OF ACTIVITY COEFFICIENTS OF COMPONENTS IN BINARY LIQUID MIXTURES1

1960 ◽  
Vol 64 (4) ◽  
pp. 442-446 ◽  
Author(s):  
Sherril D. Christian ◽  
Edward Neparko ◽  
Harold E. Affsprung
Keyword(s):  
Activity Coefficients ◽  
New Method ◽  
Binary Liquid ◽  
Determination Of Activity

Selective Sampling and Orientation of Non-Homogeneous Tissues

1968 ◽  
Vol 26 ◽  
pp. 98-99
Author(s):  
C. C. Clawson ◽  
L. W. Anderson ◽  
R. A. Good
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscopy ◽  
Random Sampling ◽  
New Method ◽  
Microscope Examination ◽  
Small Areas ◽  
Selective Sampling ◽  
Large Numbers ◽  
Specific Orientation

Investigations which require electron microscope examination of a few specific areas of non-homogeneous tissues make random sampling of small blocks an inefficient and unrewarding procedure. Therefore, several investigators have devised methods which allow obtaining sample blocks for electron microscopy from region of tissue previously identified by light microscopy of present here techniques which make possible: 1) sampling tissue for electron microscopy from selected areas previously identified by light microscopy of relatively large pieces of tissue; 2) dehydration and embedding large numbers of individually identified blocks while keeping each one separate; 3) a new method of maintaining specific orientation of blocks during embedding; 4) special light microscopic staining or fluorescent procedures and electron microscopy on immediately adjacent small areas of tissue.

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