Effective collision cross-sections for the thermal conductivity of a polyatomic–monatomic binary gas mixture

1987 ◽  
Vol 83 (2) ◽  
pp. 387-401 ◽  
Author(s):  
F. R. W. McCourt ◽  
Wing-Ki Liu
Keyword(s):  
Thermal Conductivity ◽  
Cross Sections ◽  
Gas Mixture ◽  
Binary Gas Mixture ◽  
Collision Cross Sections ◽  
Effective Collision

Quantum mechanical calculations of effective collision cross-sections for He-N2interaction

1991 ◽  
Vol 72 (6) ◽  
pp. 1347-1364 ◽  
Author(s):  
Frederick R.W. McCourt ◽  
Velisa Vesovic ◽  
William A. Wakeham ◽  
Alan S. Dickinson ◽  
Merih Mustafa
Keyword(s):  
Cross Sections ◽  
Quantum Mechanical ◽  
Quantum Mechanical Calculations ◽  
Collision Cross Sections ◽  
Effective Collision

Fluorescence decay of aromatic vapours. III. Single vibronic lifetimes and collision cross-sections for pyrimidine

1978 ◽  
Vol 31 (9) ◽  
pp. 1875 ◽  
Author(s):  
PR Nott ◽  
BK Selinger
Keyword(s):  
Small Molecule ◽  
Cross Sections ◽  
Pressure Dependence ◽  
Hard Sphere ◽  
Pressure Range ◽  
Fluorescence Decay ◽  
Decay Process ◽  
Intersystem Crossing ◽  
Collision Cross Sections ◽  
Effective Collision

In this paper the results of a lifetime study of the 1B1 state of pyrimidine vapour in the pressure range 1.2-60 Pa are presented. These lifetimes show an extraordinary pressure dependence, with collision cross-sections of 30-40 times hard sphere. It is shown that pyrimidine behaves as a small molecule. The collision-induced decay process is intersystem crossing and it is the most effective collision-induced process yet reported for the small-molecule limit.

scholarly journals An experimental study of the motion of ice past obstacles by the process of regelation

1976 ◽  
Vol 17 (75) ◽  
pp. 79-98 ◽  
Author(s):  
E. M. Morris
Keyword(s):  
Thermal Conductivity ◽  
Experimental Study ◽  
Cross Sections ◽  
Transition Point ◽  
Water Layer ◽  
Single Object ◽  
Two Systems ◽  
Basal Sliding

AbstractThe results of regelation experiments, in which a single object is pulled through ice, cannot be applied directly to the problem of basal sliding in glaciers because the two systems have different geometries. When the force applied to a single object is small, impurities trapped in the regelation water-layer around the object inhibit the regelation process. At larger forces, above the Drake-Shreve transition point, impurities are shed in a trace behind the object. However, when ice moves over a series of obstacles a trace may exist above and below the transition point. The regelation velocity below the transition point is not reduced by the effect of trapped impurities. In an experiment in which brass cylingerrs of various cross-sections rotate in ice, the ratio between the expected regelation velocity, calculated using the basal-sliding theory of Nye, and the measured regelation velocity is 8±2, both above and below the transition point. The same ratio has been obtained by other workers with wires of similar thermal conductivity above the transition point. Measurements of température differences indicate that supercooling cannot be the main source of the unexpectedly low regelation velocities above the transition point.

scholarly journals Influence of Casting Solvents on CO2/CH4 Separation Using Polysulfone Membranes

Membranes ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 286
Author(s):  
Roba M. Almuhtaseb ◽  
Ahmed Awadallah-F ◽  
Shaheen A. Al-Muhtaseb ◽  
Majeda Khraisheh
Keyword(s):  
High Efficiency ◽  
In Situ Synthesis ◽  
Separation Process ◽  
Polymeric Membranes ◽  
Gas Mixture ◽  
Manufacturing Cost ◽  
Binary Gas Mixture ◽  
Maximum Permeability ◽  
Polysulfone Membranes

Polysulfone membranes exhibit resistance to high temperature with low manufacturing cost and high efficiency in the separation process. The composition of gases is an important step that estimates the efficiency of separation in membranes. As membrane types are currently becoming in demand for CO2/CH4 segregation, polysulfone will be an advantageous alternative to have in further studies. Therefore, research is undertaken in this study to evaluate two solvents: chloroform (CF) and tetrahydrofuran (THF). These solvents are tested for casting polymeric membranes from polysulfone (PSF) to separate every single component from a binary gas mixture of CO2/CH4. In addition, the effect of gas pressure was conducted from 1 to 10 bar on the behavior of the permeability and selectivity. The results refer to the fact that the maximum permeability of CO2 and CH4 for THF is 62.32 and 2.06 barrer at 1 and 2 bars, respectively. Further, the maximum permeability of CF is 57.59 and 2.12 barrer at 1 and 2 bars, respectively. The outcome selectivity values are 48 and 36 for THF and CF at 1 bar, accordingly. Furthermore, the study declares that with the increase in pressure, the permeability and selectivity values drop for CF and THF. The performance for polysulfone (PSF) membrane that is manufactured with THF is superior to that of CF relative to the Robeson upper bound. Therefore, through the results, it can be deduced that the solvent during in-situ synthesis has a significant influence on the gas separation of a binary mixture of CO2/CH4.

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