The Temperature Dependence of the Diffusion Coefficients of Ar, CO2, CH4, CH3Cl, CH3Br, and CHCl2F in Water

1973 ◽  
Vol 51 (6) ◽  
pp. 944-952 ◽  
Author(s):  
Dow M. Maharajh ◽  
John Walkley
Keyword(s):  
Diffusion Coefficient ◽  
Temperature Dependence ◽  
Linear Relationship ◽  
Diffusion Coefficients ◽  
Hard Sphere ◽  
Solute Molecule ◽  
Temperature Range ◽  
Good Agreement

Diffusion coefficient values are reported over a 0 to 35 °C temperature range for Ar, CO2, CH4, CH3Br, CH3Cl, and CHCl2F in water. Various empirical theories relating these diffusion coefficient values to the viscosity of water (η) and the size of the diffusing solute molecule are examined. None are found valid though a linear relationship is found to hold between log D and log η for all systems. McLaughlin's hard sphere theory is examined and found in surprisingly good agreement with experiment. It is seen, however, that this theory cannot adequately predict the temperature dependence of the diffusion coefficient of the solute.

scholarly journals Band Gap Energy in Silicon

2009 ◽  
Vol 8 (2 and 3) ◽  
Author(s):  
Jeremy Low ◽  
Michael Kreider ◽  
Drew Pulsifer ◽  
Andrew Jones ◽  
Tariq Gilani
Keyword(s):  
Temperature Dependence ◽  
Linear Relationship ◽  
Band Gap ◽  
Energy Gap ◽  
Band Gap Energy ◽  
Constant Current ◽  
Gap Energy ◽  
Temperature Range ◽  
Good Agreement

The band gap energy, Eg in silicon was found by exploiting the linear relationship between the temperature and voltage for the constant current in the temperature range of 275 K to 333 K. Within the precision of our experiment, the results obtained are in good agreement with the known value energy gap in silicon. The temperature dependence of Eg for silicon has also been studied.

Implementation of a perturbation model for a dilute binary liquid and comparison of model mass diffusion coefficients with microgravity experiment results for liquid Pb 1 wt % Au

2009 ◽  
Vol 87 (8) ◽  
pp. 933-944
Author(s):  
Paul J. Scott ◽  
Reginald W. Smith
Keyword(s):  
Diffusion Coefficient ◽  
Molecular Dynamic ◽  
Coordination Number ◽  
Diffusion Coefficients ◽  
Hard Sphere ◽  
Mass Diffusion ◽  
Embedded Atom ◽  
Hard Sphere Liquid ◽  
The Mean ◽  
Good Agreement

The estimation of mass diffusion coefficients, through Earth-bound experiments, remains difficult, due to the frequent occurrence of dominating convective flows resulting from gravity-driven density gradients caused by temperature and concentration gradients. To partly remedy this, a series of capillary mass diffusion experiments has been performed in microgravity on a number of different space platforms, sometimes performed on a microgravity isolation mount, to further reduce the platform operational noise referred to as “g-jitter”. Theoretical comparisons are sought for the experimental observations. Two numerical models have been developed based on perturbation theory. We have used the Lado criteria for minimizing the difference in free energy between the multispecies liquid of interest and a reference hard-sphere liquid. The hard-sphere liquid is characterized by the rational function approximation of the partial radial distribution functions. The effective embedded atom like glue potential has been used to model the liquid of interest. This has necessitated introducing the mean coordination number as an additional parameter. Isothermal compressibility has been used to determine the mean coordination number. The initialization of the numerical solutions, and the extension of solutions over the experimental range of temperatures have been demonstrated for Pb 1 wt % Au. The model results have been used to estimate the mass diffusion coefficients by applying the Enskog equation to the reference hard-sphere liquid. For consideration of capillary experiments, a definition of total mass diffusion coefficient, Dtot, has been introduced to characterize reverse Kirkaldy simultaneous diffusion. The mixed diffusion coefficient estimate is in good agreement with the mixed diffusion coefficient estimated from the velocity correlation of molecular dynamic simulations. Dtot and D11 are in good agreement with the experimental results indicating that reverse Kirkaldy simultaneous diffusion has had an influence on the experiment. Good agreement between the mixed mass diffusion coefficient and the result from molecular dynamic simulation indicates the perturbation models can predict the mixed coefficient. These models may assist in the analysis of data from both Earth-bound and microgravity, mass diffusion experiments when the required embedded atom type potentials are available.

scholarly journals Band Gap Energy in Silicon

2008 ◽  
Vol 7 (1) ◽  
Author(s):  
Jeremy Low ◽  
Michael Kreider ◽  
Drew Pulsifer ◽  
Andrew Jones ◽  
Tariq Gilani
Keyword(s):  
Temperature Dependence ◽  
Linear Relationship ◽  
Band Gap ◽  
Energy Gap ◽  
Band Gap Energy ◽  
Constant Current ◽  
Gap Energy ◽  
Temperature Range ◽  
Good Agreement

The band gap energy Eg in silicon was found by exploiting the linear relationship between the temperature and voltage for the constant current in the temperature range of 275 K to 333 K. Within the precision of our experiment, the results obtained are in good agreement with the known value energy gap in silicon. The temperature dependence of Eg for silicon has also been studied.

Temperature Dependence of the Diffusion of 1,2-Dichloroethane, 1,1,1-Trichloroethane, Trichloroethylene, and Tetrachloroethylene in Air

1971 ◽  
Vol 49 (11) ◽  
pp. 1965-1967 ◽  
Author(s):  
Harry Watts
Keyword(s):  
Temperature Dependence ◽  
Diffusion Coefficients ◽  
Room Temperature ◽  
Evaporation Method ◽  
Temperature Range ◽  
Boiling Points ◽  
Rate Of Evaporation

The diffusion coefficients in air of 1,1-dichloroethane, 1,1,1-trichloroethane, trichloroethylene, and tetrachloroethylene have been measured over a temperature range from room temperature to close to their boiling points by a rate of evaporation method.

Temperature dependence of tracer diffusion coefficients in polystyrene

1986 ◽  
Vol 1 (1) ◽  
pp. 202-204 ◽  
Author(s):  
Peter F. Green ◽  
Edward J. Kramer
Keyword(s):  
Molecular Weight ◽  
Diffusion Coefficient ◽  
Shear Rate ◽  
Temperature Dependence ◽  
Diffusion Coefficients ◽  
Tracer Diffusion ◽  
Tracer Diffusion Coefficient ◽  
Critical Molecular Weight ◽  
Tracer Diffusion Coefficients ◽  
Monomeric Friction Coefficient

The temperature dependence of the tracer diffusion coefficient D* of long deuterated polystyrene (d-PS) chains of molecular weight M>Mc, where Mc is the critical molecular weight for entanglement, diffusing into highly entangled PS matrices, each of molecular weight P = 2×107, is studied using forward recoil spectrometry. It is found that the temperature dependence of D*/T, reflected primarily in the monomeric friction coefficient, is accurately described by a Vogel equation. The constants that are used to fit these results are independent of M and are the same as those used to fit the temperature dependence of the zero shear rate viscosity of polystyrene.

Measurement of Mass Diffusion Coefficient of Multi-Component System in Aqueous Media by Phase Shifting Interferometer

2010 ◽  
Vol 297-301 ◽  
pp. 624-630 ◽  
Author(s):  
Atsuki Komiya ◽  
Juan F. Torres ◽  
Shigenao Maruyama
Keyword(s):  
Diffusion Coefficient ◽  
Sodium Chloride ◽  
Diffusion Coefficients ◽  
Superposition Principle ◽  
Aqueous Media ◽  
Mass Diffusion ◽  
Component System ◽  
Component Solution ◽  
Multi Component System ◽  
Good Agreement

This paper describes a novel technique to determine mass diffusion coefficients of multi-component system within a transparent mixture by using an optical system. The mixture is composed of sodium chloride and lysozyme as solutes. Binary and multi-component solution experiments were conducted separately under constant temperature conditions. By measuring transient diffusion fields inside the cell, as well as for mixed multi-component solutions, it was confirmed that within the concentration ranges considered in this study, the diffusion of each solute inside the cell progresses independently. This indicates the superposition principle of concentration for certain levels of sodium chloride and lysozyme within the cell. Furthermore, by using this concentration superposition principle and an inverse analysis based on the conjugate gradient method, the diffusion coefficients of each solute in the mixture were successfully obtained from several multi-component experiments. Each obtained diffusion coefficient was good agreement with the determined diffusion coefficient from binary experiment.

Diffusion of some Hydrocarbons in Air: a Regularity in the Diffusion Coefficients of a Homologous Series

1972 ◽  
Vol 50 (1) ◽  
pp. 31-34 ◽  
Author(s):  
Robert W. Elliott ◽  
Harry Watts
Keyword(s):  
Molecular Weight ◽  
Diffusion Coefficient ◽  
Linear Relationship ◽  
Diffusion Coefficients ◽  
Homologous Series ◽  
Prediction Equations

Diffusion coefficients in air at 298.2 °K and 1 atm pressure are reported for ethane, ethene, ethyne, cyclopropane, propene, propadiene, propyne, butane, 1-butene, 2-methylpropene, cis-2-butene, trans-2-butene, 1,3-butadiene, 1-butyne, 2-methylbutane, 2,2-dimethylpropane, cyclopentane, and 1-pentene.A linear relationship, valid for alkanes and alkenes, has been found between the diffusion coefficient and the reduced molecular weight of the members of a homologous series and air.Diffusion coefficients calculated by ten prediction equations were generally lower than those observed.

scholarly journals Неизотермическая нуклеация в твердом растворе CuCl в стекле: температурная область образования закритических зародышей фазы CuCl

2018 ◽  
Vol 60 (5) ◽  
pp. 984
Author(s):  
В.И. Лейман ◽  
А.Л. Ашкалунин ◽  
П.М. Валов ◽  
О.Ю. Деркачева ◽  
В.М. Максимов
Keyword(s):  
Solid Solution ◽  
Diffusion Coefficient ◽  
Critical Radius ◽  
Formation Rate ◽  
Half Width ◽  
Experimental Dependence ◽  
Average Radius ◽  
Temperature Range ◽  
Good Agreement

AbstractIt is established both experimentally and by calculations that the nuclei of CuCl phase do not form in the solid solution of CuCl in the glass at the temperature T _u ≥ 600°C. At the temperature of 500°C, nuclei do not form due to a low diffusion coefficient. In the temperature range of 500–600°C maximums of the flow of new clusters and the critical radius are almost at the same temperature. The supersaturation is minimal in the area of maximum. The experimental dependence of the formation rate of CuCl clusters on temperature is in a good agreement with the calculated one. It is shown that the concentration of nuclei, its average radius, and the width of distribution by radii can be effectively controlled using the cooling “on the top.” The narrow distributions of CuCl clusters in the glass with the relative half-width of about 3.7% are obtained.

Sign in / Sign up

Export Citation Format

Share Document