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Bioresource and Agricultural Engineering Commons™
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Full-Text Articles in Bioresource and Agricultural Engineering
Stress-Induced Infrared Frequency Shifts In Polyethylene, G. A. Pfeffer, D. W. Noid
Stress-Induced Infrared Frequency Shifts In Polyethylene, G. A. Pfeffer, D. W. Noid
US Department of Energy Publications
The molecular dynamics technique is used to study the spectral response of a polyethylene chain in a crystal environment under a mechanical deformation. The MUSIC method, which was previously shown to accurately compute dispersion curves from the time-dependent structure factor, is used. A complete characterization of frequency shifts is presented for various lamellar thickness, temperatures, stress (or pressure), and mass defects.
Physiological Diversity And Distributions Of Heterotrophic Bacteria In Deep Cretaceous Sediments Of The Atlantic Coastal Plain, James K. Fredrickson, David L. Balkwill, John M. Zachara, Shu-Mei W. Li, Fred J. Brockman, Mary Simmons
Physiological Diversity And Distributions Of Heterotrophic Bacteria In Deep Cretaceous Sediments Of The Atlantic Coastal Plain, James K. Fredrickson, David L. Balkwill, John M. Zachara, Shu-Mei W. Li, Fred J. Brockman, Mary Simmons
US Department of Energy Publications
A series of 23 intact core segments was obtained from two distinct deep subsurface geological formations, the Middendorf and the Cape Fear formations, underlying the southeastern coastal plain of South Carolina. The Middendorf formation in this region consists of permeable, saturated, sandy sediments; the Cape Fear formation consists mainly of less permeable sediments. The core segments were separated by vertical distances ranging from several centimeters to 48 m. Aerobic chemoheterotrophic bacteria were enumerated on a dilute medium, and populations ranged from 3.1 to 6.4 log CFU g of sediment-1 in the Middendorf cores and from below detection to 4.3 …
Identification Of Solubility-Controlling Solid Phases In A Large Fly Ash Field Lysimeter, Jonathan S. Fruchter, Dhanpat Rai, John M. Zachara
Identification Of Solubility-Controlling Solid Phases In A Large Fly Ash Field Lysimeter, Jonathan S. Fruchter, Dhanpat Rai, John M. Zachara
US Department of Energy Publications
Samples of pore fluids and leachates were obtained from a large fly ash field lysimeter in central Pennsylvania. The fly ash in the lysimeter was usually only partially saturated, and only 0.3 pore volumes of water leached through the lysimeter during the 3-year study period. The samples were analyzed for major and trace inorganic anions and cations. The resulting analyses were modeled by using an equilibrium speciation/solubility code to test the hypothesis that the solubilities of at least some species in the fly ash leachate were controlled by solid phases. Potential solubility-controlling solids were identified for Al, Ba, Ca, Cr, …
Influence Of Mineral-Bound Humic Substances On The Sorption Of Hydrophobic Organic Compounds, Ellyn M. Murphy, John M. Zachara, Steven C. Smith
Influence Of Mineral-Bound Humic Substances On The Sorption Of Hydrophobic Organic Compounds, Ellyn M. Murphy, John M. Zachara, Steven C. Smith
US Department of Energy Publications
The sorption of three hydrophobic organic compounds (HOC) was investigated on hematite and kaolinite that had been coated with natural humic substances over a mass percent carbon range of 0.01-0.5%. Increasing quantities of sorbed humic substances increased the sorption of HOC. Anthracene, the most hydrophobic HOC, showed the greatest sorption enhancement, while the most aromatic coating, peat humic acid, was the strongest sorbent. Depending on the type of humic acid coating and the mineral substrate, the experimental Koc values were either higher or lower than those predicted by the Kow The sorptivity of a given humic acid for …
Sorption Of Aminonapht Halene And Quinoline On Amorphous Silica, John M. Zachara, Calvin C. Alnsworth, Christina Cowan, Ronald Schmidt
Sorption Of Aminonapht Halene And Quinoline On Amorphous Silica, John M. Zachara, Calvin C. Alnsworth, Christina Cowan, Ronald Schmidt
US Department of Energy Publications
The adsorption of quinoline and aminonaphthalene was investigated from aqueous solution on amorphous silica SiO2. Amorphous SiO2 was not a strong adsorbent of these compounds and quinoline was adsorbed more strongly than aminonaphthalene. The adsorption of both compounds varied with pH. A maximum in adsorption occurred near their respective pKa's. Temperature effects were significant, suggesting enthalpy contributions in the range of H bonding. Both compounds appeared to adsorb via identical mechanisms that included H bonding and ion exchange. The greater basicity of quinoline combined with (1) the enhanced electron-donating properties of the heteroatom N and …