Geology, hydrology, and quality of water in the Madera area, San Joaquin Valley, California /

Three folded maps in pocket.

Neutron slowing down in group diffusion theory

"Contract AT-11-1-GEN-14. Bettis PLant, Pittsburgh, Pa., operated for the U. S. Atomic Energy Commission by Westinghouse Electric Corporation."

Potential climatic impacts of increasing atmospheric CO with emphasis on water availability and hydrology in the United States : report prepared for the Environmental Protection Agency /

"April 1984."

Ground-water hydrology before, during, and after coal strip mining of a small watershed in Coshocton County, Ohio /

"U.S. Bureau of Mines contracts J0166054 and J0166055."

Further studies of bone isografts in diffusion chambers; final progress report.

Mode of access: Internet.

Unitgraph procedures : a discussion of methods in regular practice or experimental use by the Hydrology Branch, Division of Project Planning /

Mode of access: Internet.

Unitgraph procedures : a discussion of methods in regular practice or experimental use by the Hydrology Branch, Division of Project Planning /

Mode of access: Internet.

A short history of Anglo-Saxon freedom : the polity of the English-speaking race : outlined in its inception, development, diffusion, and present condition /

Includes bibliographical footnotes and index.

Hydrology of the Tertiary-Cretaceous aquifer system in the vicinity of Fort Rucker Aviation Center, Alabama /

Mode of access: Internet.

A diffusion and T2 relaxation MRI study of the ovine lumbar intervertebral disc under compression in vitro

The ovine lumbar intervertebral disc is a useful model for the human lumbar disc. We present preliminary estimates of diffusion coefficients and T-2 relaxation times in a pilot MRI study of the ovine lumbar intervertebral disc during uniaxial compression in vitro, and identify factors that hamper the ability to accurately monitor the temporal evolution of the effective diffusion tensor at high spatial resolution.

Diffusion of linear paraffins in nanoporous silica

The diffusion of hexane, heptane, octane, and decane in nanoporous MCM-41 silica at various temperatures is investigated by the zero-length-column method. The diffusion coefficients are derived by a complete-time-range analysis of desorption curves at different purge flow rates and temperatures. The results show that the calculated low-coverage diffusivity values decrease monotonically, and the derived Henry's law constants increase, as the carbon number of paraffins increases. The study reveals that transport is strongly influenced by intracrystalline diffusion and dominated by the sorbate-sorbent interaction. The diffusion activation energy and adsorption isosteric heat at zero loading increase monotonically with the carbon number of linear paraffins, but their ratio is essentially constant for each adsorbate compound.

Diffusion of n-decane in mesoporous MCM-41 silicas

We investigate here the diffusion of n-decane in nanoporous MCM-41 silicas with pore diameters between 3.0 and 4.3 nm, and at various temperatures and purge flow rates, by the Zero Length Column method. A complete-time-range analysis of desorption curves is used to derive the diffusion coefficient, and the effect of pore size, purge flow rate and temperature on the diffusion character is systematically studied. The results show that the calculated low-coverage diffusivity values are strongly dependent on temperature but only weakly dependent on pore size. The study reveals that transport is controlled by intracrystalline diffusion and dominated by sorbate-sorbent interaction, with the experimental isosteric heat matching the potential energy of flat-lying n-decane molecules on the surface, determined using a united atom model. The diffusion activation energy and adsorption isosteric heat at zero loading for the different pore size MCM-41 samples vary in a narrow range respectively, and their ratio is essentially constant over the pore size range studied. The study shows that the ZLC method is an effective tool to investigate the diffusion kinetics of hydrocarbons in mesoporous MCM-41 materials. (c) 2005 Elsevier Inc. All rights reserved.