Estimates of gas

Ganapathy, V, Chart Gives Fast Estimate of Gas Heat-Transfer Coefficient, Oil and Gas Journal, May 5 (1980) p. 243. 

Fukui, S. and Kaneko, R., Estimation of Gas Film Lubrication Effects Beneath Sliding Bushings of Micromotors Using a Molecular Gas Film Lubrication Equation," Wear, Vol. 168,1993, pp. 175-179. 

S. W., Melton, C. M. Estimation of gas-liquid chromatographic retention times from molecular structure.. Chromatogr. A 1994, 662, 269-280. 

Hermann C, Dewes I, Schumpe A (1995) The estimation of gas solubilities in salt solutions. Chem Eng Sci 50 1673-1675... 

Klamt, A. (1993) Estimation of gas-phase hydroxyl radical rate constants of organic compounds from molecular orbital calculations. Chemosphere 26, 1273-1289. 

Martinez, M. R., "Estimation of Gas-Phase Thermodynamic Parameters," Quantum Chemistry Program Exchange, Program 244 (1974). 

Martinez, M. R., Estimation of Gas-Phase Thermokinetic Parameters Thermochemical Group Additivity Computer Program (TGAP). NTIS AD-762-614 and AD-769-631, 1973. 

Klamt, A. Estimation of Gas-Phase Hydroxyl Radical Rate Constants of Organic Compounds from Molecular Orbital Calculations, Chemosphere, 26, 1273-1289 (1993). 

Sources and Typical Concentrations of HO in the Troposphere Rate Constants and Tropospheric Half-Lives for Reactions with HO Estimation of Gas-Phase HO Reaction Rate Constants Illustrative Example 16.3 Estimating Tropospheric Half-Lives of Organic Pollutants... 

Chapman C M. Gilibaro L G, Nienow A W (1982) A dynamic response technique for the estimation of gas-liquid mass transfer coefficients in a stirred vessel, Chemical Engineering Science 37 1891-896. 

Estimates of gas chromatographs in use today are as high as 150,000. Today there are now well over 30 manufacturers of over 130 different models. 

Even the most conservative estimates of gas in hydrates in Table 7.1 indicate their enormous energy potential. Kvenvolden (1988) indicated that the 10,000 Gt (1 Gt = 1015 g) carbon or 1.8 x 1016 m3 of methane in hydrates may surpass the available, recoverable conventional methane by two orders of magnitude, or a factor of two larger than the methane equivalent of the total of all fossil fuel... 

More recent literature regarding generalized correlational efforts for gas holdup is adequately reviewed by Tsuchiya and Nakanishi [Chem. Eng Sci., 47(13/14), 3347 (1992)] and Sotelo etal. [Inf. Chem. Eng., 34(1), 82-90 (1994)]. Sotelo et al. (op. cit.) have developed a dimensionless correlation for gas holdup that includes the effect of gas and liquid viscosity and density, interfacial tension, and diffuser pore diameter. For systems that deviate significantly from the waterlike liquids for which Fig. 14-104 is applicable, their correlation (the fourth numbered equation in the paper) should be used to obtain a more accurate estimate of gas holdup. Mersmann (op. cit.) and Deckwer et al. (op. cit.) should also be consulted. 

Fig. 3.24. The Duan et al. (1992b) model estimates of gas fugacity coefficients at 1 and 20 bars between 273 and 1473 K compared to extrapolations below 273 K generated by the FREZCHEM model for a methane and b carbon dioxide. Reprinted from Marion et al. (2006) with permission...

Sahsuvar, L., Helm, P.A., Jantunen, L.M., Bidleman, T.F. (2003) Henry s law constants for CX-, 3-, and y-hexachlorocyclohexanes (HCHs) as a function of temperature and revised estimates of gas exchange in Arctic regions. Atmos. Environ. 37, 983-992. Saito, S., Tanoue, A., Matsuo, M. (1992) Applicability of the i/o-characters to a quantitative description of bioconcentration of organic chemicals in fish. Chemosphere 24(1), 81-87. 

The values of permeability coefficients for He, O2, N2, CO2, and CH4 in a variety of dense (isotropic) polymer membranes and the overall selectivities (ideal separation factors) of these membranes to the gas pairs He/N2,02/N2, and CO2/CH4 at 35°C have been tabulated in numerous reviews (Koros and Heliums, 1989 Koros, Fleming, and Jordan et al., 1988 Koros, Coleman, and Walker, 1992). Moreover, several useful predictive methods exist to allow estimation of gas permeation through polymers, based on their structural repeat units. The values of the permeability coefficients for a given gas in different polymers can vary by several orders of magnitude, depending on the nature of the gas. Thevalues oftheoverall selectivities vary by much less. Particularly noteworthy is the fact that the selectivity decreases with increasing permeability. This is the well-known inverse selectivity/permeability relationship of polymer membranes, which complicates the development of effective membranes for gas separations. 

The approach of research institutes AGLARG [9] was used for an operative estimation of gas sorption capacity for carbon sorbents. According to it micropore volume and the specific surface area have been chosen as determining parameters. To obtain the function approximating dependence of hydrogen sorption capacity on carbon materials from value of a specific surface area (at pressure 0.1 MPa and temperature 77 K), we used our experimental data (Table 1) and an experimental database (Table 2) of group of institutes - Inorganic Chemistry and Catalysis, Debye Institute, Utrecht University [10],... 

Eq. (3) is a one-parameter correlation (k being the unknown parameter) that permits estimation of gas-liquid interfacial areas under high pressure provided the high pressure liquid hold-up pL is known the expression between brackets can be seen as an enhancement factor of the interfacial area due to pressure effect. Values of pUi and a0 at atmospheric pressure are also required. Using available interfacial area data of Wammes et al. [5] and the data of this work, the best estimate of K is 4.9 104. Predictions of present results and of those reported by... 

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