MUTUAL DIFFUSION IN POLAR–NONPOLAR GASES: KRYPTON – SULPHUR DIOXIDE AND KRYPTON – DIETHYL ETHER

1966 ◽  
Vol 44 (11) ◽  
pp. 2595-2600 ◽  
Author(s):  
B. N. Srivastava ◽  
Anil Saran
Keyword(s):  
Diethyl Ether ◽  
Sulphur Dioxide ◽  
Diffusion Coefficients ◽  
Scintillation Counter ◽  
Interaction Parameters ◽  
Combination Rules ◽  
Lennard Jones ◽  
Mass Correction ◽  
Normal Diffusion ◽  
Interdiffusion Coefficients

The interdiffusion coefficients for the gas mixtures of Kr–SO2 and Kr–(C2H5)2O have been measured in the temperature range 1 to 45 °C by the two-bulb technique of Ney and Armistead using radioactive 85Kr as tracer. A scintillation counter has been used for analyzing the concentration of 85Kr at different times. A mass correction was applied to get the normal diffusion coefficients for both the systems.The experimental D12 values have been employed to get the unlike interaction parameters on the Lennard-Jones (12:6) potential and compared with those obtained by using the combination rules for a polar–nonpolar system and the force constants of the polar gas from viscosity as well as from second virial data. For interpreting second virial data for polar gases the assumption of an off-center dipole is found to yield better interaction parameters.

scholarly journals Time-Dependent Diffusion Coefficients for Chaotic Advection due to Fluctuations of Convective Rolls

Fluids ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 99 ◽  
Author(s):  
Kazuma Yamanaka ◽  
Takayuki Narumi ◽  
Megumi Hashiguchi ◽  
Hirotaka Okabe ◽  
Kazuhiro Hara ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Liquid Crystals ◽  
Diffusion Coefficients ◽  
Coarse Graining ◽  
Chaotic Advection ◽  
Time Dependent ◽  
Local Order ◽  
Weak Turbulence ◽  
Normal Diffusion ◽  
Convective Rolls

The properties of chaotic advection arising from defect turbulence, that is, weak turbulence in the electroconvection of nematic liquid crystals, were experimentally investigated. Defect turbulence is a phenomenon in which fluctuations of convective rolls arise and are globally disturbed while maintaining convective rolls locally. The time-dependent diffusion coefficient, as measured from the motion of a tagged particle driven by the turbulence, was used to clarify the dependence of the type of diffusion on coarse-graining time. The results showed that, as coarse-graining time increases, the type of diffusion changes from superdiffusion → subdiffusion → normal diffusion. The change in diffusive properties over the observed timescale reflects the coexistence of local order and global disorder in the defect turbulence.

PREDICTION OF THE TRANSPORT PROPERTIES OF SF6 WITH O2, CO2, CF4, N2 AND CH4 MIXTURES AT LOW DENSITY BY THE INVERSION METHOD (PART II)

2004 ◽  
Vol 03 (01) ◽  
pp. 69-90 ◽  
Author(s):  
BEHZAD HAGHIGHI ◽  
ALIREZA HASSANI DJAVANMARDI ◽  
MOHAMAD MEHDI PAPARI ◽  
MOHSEN NAJAFI
Keyword(s):  
Potential Energy ◽  
Diffusion Coefficients ◽  
Potential Energy Function ◽  
Model Potential ◽  
Inversion Method ◽  
Low Density ◽  
Initial Model ◽  
Lennard Jones ◽  
Inversion Procedure ◽  
And Diffusion

Viscosity and diffusion coefficients for five equimolar binary gas mixtures of SF 6 with O 2, CO 2, CF 4, N 2 and CH 4 gases are determined from the extended principle of corresponding states of viscosity by the inversion technique. The Lennard–Jones 12-6 (LJ 12-6) potential energy function is used as the initial model potential required by the technique. The obtained interaction potential energies from the inversion procedure reproduce viscosity within 1% and diffusion coefficients within 5%.

scholarly journals Role of different factors affecting interdiffusion in Cu(Ga) and Cu(Si) solid solutions

2014 ◽  
Vol 470 (2161) ◽  
pp. 20130464 ◽  
Author(s):  
Sangeeta Santra ◽  
Hongqun Dong ◽  
Tomi Laurila ◽  
Aloke Paul
Keyword(s):  
Solid Solutions ◽  
Diffusion Coefficients ◽  
Tracer Diffusion ◽  
Impurity Diffusion ◽  
Factors Affecting ◽  
The Matrix ◽  
Bond Strengths ◽  
Interdiffusion Coefficients ◽  
Formation Energies

A detailed diffusion study was carried out on Cu(Ga) and Cu(Si) solid solutions in order to assess the role of different factors in the behaviour of the diffusing components. The faster diffusing species in the two systems, interdiffusion, intrinsic and impurity diffusion coefficients, are determined to facilitate the discussion. It was found that Cu was more mobile in the Cu–Si system, whereas Ga was the faster diffusing species in the Cu–Ga system. In both systems, the interdiffusion coefficients increased with increasing amount of solute (e.g. Si or Ga) in the matrix (Cu). Impurity diffusion coefficients for Si and Ga in Cu, found out by extrapolating interdiffusion coefficient data to zero composition of the solute, were both higher than the Cu tracer diffusion coefficient. These observed trends in diffusion behaviour could be rationalized by considering: (i) formation energies and concentration of vacancies, (ii) elastic moduli (indicating bond strengths) of the elements and (iii) the interaction parameters and the related thermodynamic factors. In summary, we have shown here that all the factors introduced in this paper should be considered simultaneously to understand interdiffusion in solid solutions. Otherwise, some of the aspects may look unusual or even impossible to explain.

scholarly journals Gaseous Diffusion Coefficients of Dimethyl Ether and Diethyl Ether into Air, Nitrogen and Oxygen

Netsu Bussei ◽  
2006 ◽  
Vol 20 (2) ◽  
pp. 83-86 ◽  
Author(s):  
Naoki Matsunaga ◽  
Morio Hori ◽  
Akira Nagashima
Keyword(s):  
Dimethyl Ether ◽  
Diethyl Ether ◽  
Diffusion Coefficients ◽  
Gaseous Diffusion

Spectra of H2–Ar, H2–Kr, and H2–Xe Van der Waals Complexes in Pressure-Induced Infrared Absorption

1971 ◽  
Vol 49 (2) ◽  
pp. 230-242 ◽  
Author(s):  
A. K. Kudian ◽  
H. L. Welsh
Keyword(s):  
Infrared Absorption ◽  
Path Length ◽  
Vibrational State ◽  
Van Der Waals ◽  
Rotational Quantum Number ◽  
Van Der Waals Complexes ◽  
Intermolecular Potential ◽  
Combination Rules ◽  
Ground Vibrational State ◽  
Lennard Jones

Spectra of H2–Ar, H2–Kr, and H2–Xe Van der Waals complexes, accompanying the Q1(0), Q1(1), S1(0), and S1(1) transitions of the pressure-induced fundamental infrared absorption band of hydrogen, have been studied in gas mixtures at 93–180 °K with a path length of 13 m and total pressures of ~3 atm. The main features of the spectra correspond to rotational transitions in the ground vibrational state of the complex, i.e., resolved T and N lines (Δl = ± 3) and unresolved R and P lines (Δl = ± 1), where l is the rotational quantum number of the complex. The spectra are analyzed with eigenvalues derived from the wave-mechanical solution of the isotropic Lennard–Jones 12–6 potential with constants determined from the combination rules for mixed molecular species. Although there is good overall agreement, it is evident that finer details of the spectra will require the introduction of an anisotropic intermolecular potential for their explanation.

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