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Bioresource and Agricultural Engineering Commons™

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2005

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Articles 61 - 70 of 70

Full-Text Articles in Bioresource and Agricultural Engineering

Effects Of Atomic Hydrogen And Deuterium Exposure On High Polarization Gaas Photocathodes, M. Baylac, P. Adderley, J. Brittian, J. Clark, T. Day, J. Grames, J. Hansknecht, M. Poelker, M. Stutzman, A. T. Wu, A. S. Terekhov Jan 2005

Effects Of Atomic Hydrogen And Deuterium Exposure On High Polarization Gaas Photocathodes, M. Baylac, P. Adderley, J. Brittian, J. Clark, T. Day, J. Grames, J. Hansknecht, M. Poelker, M. Stutzman, A. T. Wu, A. S. Terekhov

United States Department of Energy: Publications

Strained-layer GaAs and strained-superlattice GaAs photocathodes are used at Jefferson Laboratory to create high average current beams of highly spin-polarized electrons. High electron yield, or quantum efficiency (QE), is obtained only when the photocathode surface is atomically clean. For years, exposure to atomic hydrogen or deuterium has been the photocathode cleaning technique employed at Jefferson Laboratory. This work demonstrates that atomic hydrogen cleaning is not necessary when precautions are taken to ensure that clean photocathode material from the vendor is not inadvertently dirtied while samples are prepared for installation inside photoemission guns. Moreover, this work demonstrates that QE and beam …

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Radius Of Gyration Of Polystyrene Combs And Centipedes In A Θ Solvent, Ken Terao, Brandon S. Farmer, Yo Nakamura, Hermis Iatrou, Kunlun Hong, Jimmy W. Mays Jan 2005

Radius Of Gyration Of Polystyrene Combs And Centipedes In A Θ Solvent, Ken Terao, Brandon S. Farmer, Yo Nakamura, Hermis Iatrou, Kunlun Hong, Jimmy W. Mays

United States Department of Energy: Publications

The molecular weight dependence of the radii of gyration Rg in a Θ solvent (trans-decalin) of one regular branched comb and three regular centipede polystyrenes was studied using a gel permeation chromatography system equipped with a two-angle light scattering detector and a refractive index detector. Rg in trans-decalin for each sample of particular molecular weight was about 25% smaller than that in a good solvent (tetrahydrofuran, THF). On the other hand, they are 20-40% larger than the theoretical values from the Gaussian chain model. This difference can be explained with the worm-like comb model developed by Nakamura et …

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Kinetic Desorption And Sorption Of U(Vi) During Reactive Transport In A Contaminated Hanford Sediment, Nikolla P. Qafoku, John M. Zachara, Chongxuan Liu, Paul Gassman, Odeta Qafoku, Steve Smith Jan 2005

Kinetic Desorption And Sorption Of U(Vi) During Reactive Transport In A Contaminated Hanford Sediment, Nikolla P. Qafoku, John M. Zachara, Chongxuan Liu, Paul Gassman, Odeta Qafoku, Steve Smith

United States Department of Energy: Publications

Column experiments were conducted to investigate U(VI) desorption and sorption kinetics in a sand-textured, U(VI)- contaminated (22.7 µmol kg-1) capillary fringe sediment from the U.S. Department of Energy (DOE) Hanford site. Saturated column experiments were performed under mildly alkaline conditions representative of the Hanford site where uranyl-carbonate and calcium-uranyl-carbonate complexes dominate aqueous speciation. A U(VI)-free solution was used to study contaminant U(VI) desorption in columns where different flow rates were applied. Sorbed, contaminant U(VI) was partially labile (11.8%), and extended leaching times and water volumes were required for complete desorption of the labile fraction. Uranium- (VI) sorption was …

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Cryogenic Laser Induced U(Vi) Fluorescence Studies Of A U(Vi) Substituted Natural Calcite: Implications To U(Vi) Speciation In Contaminated Hanford Sediments, Zheming Wang, John M. Zachara, James Mckinley, Steven Smith Jan 2005

Cryogenic Laser Induced U(Vi) Fluorescence Studies Of A U(Vi) Substituted Natural Calcite: Implications To U(Vi) Speciation In Contaminated Hanford Sediments, Zheming Wang, John M. Zachara, James Mckinley, Steven Smith

United States Department of Energy: Publications

Time-resolved laser-induced fluorescence spectroscopy (TRLFS) and imaging spectromicroscopy (TRLFISM) were used to examine the chemical speciation of uranyl in contaminated subsurface sediments from the U.S. Department of Energy (U.S. DOE) Hanford Site, Washington. Spectroscopic measurements for contaminant U(VI) were compared to those from a natural, uranyl-bearing calcite (NUC) that had been found via X-ray absorption spectroscopy (XAS) to include uranyl in the same coordination environment as calcium. Spectral deconvolution of TRLFS measurements on the NUC revealed the unexpected presence of two distinct chemical environments consistent with published spectra of U(VI)-substituted synthetic calcite and aragonite. Apparently, some U(VI) substitution sites in …

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Impact Of Highly Basic Solutions On Sorption Of Cs+ To Subsurface Sediments From The Hanford Site, Usa, C.C. Ainsworth, John M. Zachara, K. Wagnon, S. Mckinley, Chongxuan Liu, Steven Smith, H.T. Schaef, Paul Gassman Jan 2005

Impact Of Highly Basic Solutions On Sorption Of Cs+ To Subsurface Sediments From The Hanford Site, Usa, C.C. Ainsworth, John M. Zachara, K. Wagnon, S. Mckinley, Chongxuan Liu, Steven Smith, H.T. Schaef, Paul Gassman

United States Department of Energy: Publications

The effect of caustic NaNO3 solutions on the sorption of 137Cs to a Hanford site micaceous subsurface sediment was investigated as a function of base exposure time (up to 168 d), temperature (10°C or 50°C), and NaOH concentration (0.1 mol/L to 3 mol/L). At 10°C and 0.1 M NaOH, the slow evolution of [Al]aq was in stark contrast to the rapid increase and subsequent loss of [Al]aq observed at 50°C (regardless of base concentration). Exposure to 0.1 M NaOH at 10°C for up to 168 d exhibited little if any measurable effect on sediment mineralogy, Cs …

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Aeration Strategies And Fan Cost Comparisons For Wheat In Mid-South Production Regions, Thomas C. Bridges, Michael D. Montross, Samuel G. Mcneill Jan 2005

Aeration Strategies And Fan Cost Comparisons For Wheat In Mid-South Production Regions, Thomas C. Bridges, Michael D. Montross, Samuel G. Mcneill

Biosystems and Agricultural Engineering Faculty Publications

Numerous factors influence the sizing of aeration fans for summer-harvested crops. Thirty years of weather data for Lexington, Kentucky, were analyzed and the cost of aeration was compared for two axial fans (afan1, afan2) and one centrifugal fan (cfan1). Aeration costs were defined as the sum of the following components: the cost of owning the fan, the cost of electricity for operating the fan, a cost for wheat shrinkage during aeration, and a cost for dry matter loss (DML). The fans were selected to deliver airflow rates of approximately one, two, and three times the recommended aeration rate of 0.11 …

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Streambank Erosion Associated With Grazing Practices In The Humid Region, Carmen T. Agouridis, Dwayne R. Edwards, Stephen R. Workman, José R. Bicudo, Benjamin K. Koostra, Eric S. Vanzant, Joseph L. Taraba Jan 2005

Streambank Erosion Associated With Grazing Practices In The Humid Region, Carmen T. Agouridis, Dwayne R. Edwards, Stephen R. Workman, José R. Bicudo, Benjamin K. Koostra, Eric S. Vanzant, Joseph L. Taraba

Biosystems and Agricultural Engineering Faculty Publications

The effects of cattle grazing on stream stability have been well documented for the western portion of the U.S., but are lacking for the east. Stream and riparian damage resulting from grazing can include alterations in watershed hydrology, changes to stream morphology, soil compaction and erosion, destruction of vegetation, and water quality impairments. However, few studies have examined the successes of best management practices (BMPs) for mitigating these effects. The objective of this project was to assess the ability of two common BMPs to reduce streambank erosion along a central Kentucky stream. The project site consisted of two replications of …

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Evaluation Of Toxic Agent Effects On Lung Cells By Fiber Evanescent Wave Spectroscopy, Pierre Lucas, David Lee Coq, Christophe Juncker, Jayne Collier, Dianne E. Boesewetter, Catherine Boussard-Pledel, Bruno Bureau, Mark R. Riley Jan 2005

Evaluation Of Toxic Agent Effects On Lung Cells By Fiber Evanescent Wave Spectroscopy, Pierre Lucas, David Lee Coq, Christophe Juncker, Jayne Collier, Dianne E. Boesewetter, Catherine Boussard-Pledel, Bruno Bureau, Mark R. Riley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Biochemical changes in living cells are detected using a fiber probe system composed of a single chalcogenide fiber acting as both the sensor and transmission line for infrared optical signals. The signal is collected via evanescent wave absorption along the tapered sensing zone of the fiber. We spectroscopically monitored the effects of the surfactant Triton X-lOO, which serves as a toxic agent simulant on a transformed human lung carcinoma type II epithelial cell line (A549). We observe spectral changes between 2800-3000 cm-1 in four absorptions bands, which are assigned to hydrocarbon vibrations of methylene and methyl groups in membrane lipids. …

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California Energy Commission Agricultural Peak Load Reduction Program Case Study: Orange Cove Id, Charles M. Burt, Daniel J. Howes Jan 2005

California Energy Commission Agricultural Peak Load Reduction Program Case Study: Orange Cove Id, Charles M. Burt, Daniel J. Howes

BioResource and Agricultural Engineering

The Orange Cove Irrigation District is located in Fresno and Tulare Counties, approximately 30 miles southeast of Fresno and 20 miles north of the City of Visalia. The Friant-Kern Canal is the district’s main source of water to supply 28,000 acres of farmland.

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California Energy Commission Agricultural Peak Load Reduction Program Case Study: Berrenda Mesa Wsd, Charles M. Burt, Daniel J. Howes Jan 2005

California Energy Commission Agricultural Peak Load Reduction Program Case Study: Berrenda Mesa Wsd, Charles M. Burt, Daniel J. Howes

BioResource and Agricultural Engineering

Berrenda Mesa Water Storage District (BMWSD) is located in the southern part of the San Joaquin Valley near Bakersfield. The district receives water from the State Water Project – California Aqueduct.

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