Results 271 to 280 of about 55,043 (308)

Electron transport and ion clustering reactions in water vapor and deuterated water vapor

The Journal of Chemical Physics, 1975
The interaction of low energy electrons and negative ions with pure water vapor and deuterated water vapor has been studied in the following two experiments: (I) A time-of-flight electron swarm experiment has been used to determine longitudinal electron diffusion coefficients, DL, in H2O and D2O for electric-field-to-pressure ratios, E/P, from 1 to 25 ...
J. F. Wilson, F. J. Davis, D. R. Nelson, R. N. Compton, Oakley H. Crawford   +4 more
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Mulch resistance to water vapor transport

Agricultural Water Management, 2011
Abstract Mulches augment soil moisture availability to plants by restraining direct evaporation of soil water. Yet, in field conditions wind decreases their resistance to water vapor transport, diminishing their efficiency as a water conservation measure. The relation between vapor transport resistance and wind speed was investigated in a wind tunnel
M. Fuchs, A. Hadas
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Calculation of the transport and relaxation properties of dilute water vapor

The Journal of Chemical Physics, 2009
Transport properties of dilute water vapor have been calculated in the rigid-rotor approximation using four different potential energy hypersurfaces and the classical-trajectory method. Results are reported for shear viscosity, self-diffusion, thermal conductivity, and volume viscosity in the dilute-gas limit for the temperature range of 250–2500 K. Of
Hellmann R, Bich E, Vogel E, Dickinson AS, Vesovic V   +4 more
openaire   +3 more sources

Water vapor transport in a series of polyarylates

Journal of Membrane Science, 2001
Abstract Water vapor sorption and transport properties are presented for a series of polyarylates. The effect of making various structural changes in the polymer backbone has been studied, by comparing the transport properties to those of the base polymer bisphenol A isophthalate.
openaire   +1 more source

Diffusion Transport of Water and Methanol Vapors in Polyvinyltrimethylsilane

Membranes and Membrane Technologies, 2019
The specifics of diffusion of water and methanol vapors in nonporous polymer films based on polyvinyltrimethylsilane (PVTMS) have been studied. The vapor diffusion coefficients have been determined by measuring the kinetics of unsteady flow through the membrane (differential method) and subsequent processing the results by functional scaling .
M. G. Shalygin, A. A. Kozlova, D. A. Syrtsova, S. Yu. Markova, O. R. Ryabova, V. V. Teplyakov   +5 more
openaire   +1 more source

Water vapor transport in structurally varied polyurethans

Journal of Macromolecular Science, Part B, 1969
Abstract A study has been made on four chain-extended polyurethan (PU) elastomers differing only in the nature of the flexible segment, namely, poly(butylene adipate) (PBA), poly(tetramethvlene oxide) (PTMO), poly(propylene oxide) (PPO), and poly(ethylene oxide) (PEO).
N. S. Schneider, L. V. Dusablon, E. W. Snell, R. A. Prosser   +3 more
openaire   +1 more source

Water Vapor Transport in Hydrophilic Polyurethanes

1974
Water uptake and water vapor transmission rates have been obtained on two series of hydrophilic segmented polyurethanes based on MDI, butanediol, and several block copolymer polyethers with varying proportions of poly(ethylene oxide) PEO and poly(propyleneoxide) PPO. In series I the ratio of PEO to PPO is varied at fixed hard segment concentration.
J. L. Illinger, N. S. Schneider, F. E. Karasz   +2 more
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Water Vapor Transport Measurement across PEMs

ECS Transactions, 2014
Water vapor transport through the PEM is one of the key parameters that can help achieve high performance and low-cost fuel cell system. Ex-situ water vapor transport rate (WVTR) measurement is extremely difficult and expensive to measure. This transport depends on many parameters such as ionomer equivalent weight, ionomer type, thickness ...
Ramesh Yadav, Greg DiLeo, Nilesh Dale, Kenzo Oshihara   +3 more
openaire   +1 more source

Transport and Sorption of Water Vapor in Activated Carbon

Journal of Environmental Engineering, 1996
Control of organic vapors by adsorption on activated carbon can be impacted by the presence of water vapor in the gas stream. As a foundation to better understand this issue, the transport and sorption of water vapor within activated carbon grains were studied.
Tsair-Fuh Lin, William W. Nazaroff
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Transport coefficients for electrons in water vapor: Definition, measurement, and calculation

The Journal of Chemical Physics, 2011
Comparison of experimental and theoretical transport data for electron swarms in water vapour over a wide range of fields provides a rigorous test of (e−, H2O) scattering cross sections over a correspondingly broad range of energies. That like should be compared with like is axiomatic, but the definition of transport coefficients at high fields, when ...
Robson, R.E., White, R.D., Ness, K.F.
openaire   +3 more sources