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Mechanistically-Based Field-Scale Models of Uranium Biogeochemistry from Upscaling Pore-Scale Experiments and Models

Description: Effective environmental management of DOE sites requires reliable prediction of reactive transport phenomena. A central issue in prediction of subsurface reactive transport is the impact of multiscale physical, chemical, and biological heterogeneity. Heterogeneity manifests itself through incomplete mixing of reactants at scales below those at which concentrations are explicitly defined (i.e., the numerical grid scale). This results in a mismatch between simulated reaction processes (formulated… more
Date: April 19, 2007
Creator: Scheibe, Tim; Tartakovsky, Alexandre; Wood, Brian & Seymour, Joe
Partner: UNT Libraries Government Documents Department

Applying EMSL Capabilities to Biogeochemistry and Environmental Research

Description: The Environmental Molecular Sciences laboratory (EMSL) is a national scientific user facility operated by the Pacific Northwest National Laboratory (PNNL) for the U.S. Department of Energy's Office of Biological and Environmental Research. Located in Richland, Washington, EMSL offers researchers a comprehensive array of cutting-edge capabilities unmatched anywhere else in the world and access to the expertise of over 300 resident users--all at one location. EMSL's resources are available on a p… more
Date: April 19, 2007
Creator: Felmy, Andy
Partner: UNT Libraries Government Documents Department

Comparison of Predictive Models for PV Module Performance (Presentation)

Description: This paper examines three models used to estimate the maximum power (P{sub m}) of PV modules when the irradiance and PV cell temperature are known: (1) the power temperature coefficient model, (2) the PVFORM model, and (3) the bilinear interpolation model. A variation of the power temperature coefficient model is also presented that improved model accuracy. For modeling values of P{sub m}, an 'effective' plane-of-array (POA) irradiance (E{sub e}) and the PV cell temperature (T) are used as mode… more
Date: May 1, 2008
Creator: Marion, B.
Partner: UNT Libraries Government Documents Department

The Center for Environmental Kinetics Analysis: an NSF- and DOE-funded Environmental Molecular Science Institute (EMSI) at Penn State

Description: Physicochemical and microbiological processes taking place at environmental interfaces influence natural processes as well as the transport and fate of environmental contaminants, the remediation of toxic chemicals, and the sequestration of anthropogenic CO2. A team of scientists and engineers has been assembled to develop and apply new experimental and computational techniques to expand our knowledge of environmental kinetics. We are also training a cohort of talented and diverse students to w… more
Date: April 19, 2007
Creator: Brantley, S. L.; Burgos, William D.; Dempsey, Brian A.; Heaney, Peter J.; Kubicki, James D.; Lichtner, Peter C. et al.
Partner: UNT Libraries Government Documents Department

Thermodynamic network model for predicting effects of substrate addition and other perturbations on subsurface microbial communities

Description: The overall goal of this project is to develop and test a thermodynamic network model for predicting the effects of substrate additions and environmental perturbations on microbial growth, community composition and system geochemistry. The hypothesis is that a thermodynamic analysis of the energy-yielding growth reactions performed by defined groups of microorganisms can be used to make quantitative and testable predictions of the change in microbial community composition that will occur when a… more
Date: April 19, 2007
Creator: Istok, Jack; Park, Melora; McKinley, James; Liu, Chongxuan; Krumholz, Lee; Spain, Anne et al.
Partner: UNT Libraries Government Documents Department

Isotopic Tracers for Biogeochemical Processes and Contaminant Transport: Hanford, Washington

Description: Our goal is to use isotopic measurements to understand how contaminants are introduced to and stored in the vadose zone, and what processes control migration from the vadose zone to groundwater and then to surface water. We have been using the Hanford Site in south-central Washington as our field laboratory, and our investigations are often stimulated by observations made as part of the groundwater monitoring program and vadose zone characterization activities. Understanding the transport of co… more
Date: April 19, 2007
Creator: DePaolo, Donald J.; Christensen, John N.; Conrad, Mark E. & Dresel, and P. Evan
Partner: UNT Libraries Government Documents Department

Stabilization of Plutonium in Subsurface Environments via Microbial Reduction and Biofilm Formation

Description: Plutonium has a long half-life (2.4 x 104 years) and is of concern because of its chemical and radiological toxicity, high-energy alpha radioactive decay. A full understanding of its speciation and interactions with environmental processes is required in order to predict, contain, or remediate contaminated sites. Under aerobic conditions Pu is sparingly soluble, existing primarily in its tetravalent oxidation state. To the extent that pentavalent and hexavalent complexes and small colloidal spe… more
Date: April 19, 2007
Creator: Boukhalfa, Hakim; Icopini, Gary A.; Reilly, Sean D. & Neu, Mary P.
Partner: UNT Libraries Government Documents Department

Mesoscale Biotransformation of Uranium: Influences of Organic Carbon Supply Rates and Sediment Oxides

Description: Remediation and long-term stewardship of uranium-contaminated sediments and groundwaters are critical problems at a number of DOE facilities and mining sites. Some remediation strategies based on in-situ bioreduction of U are potentially effective in significantly decreasing U concentrations in groundwaters. However, a number of basic processes require understanding in order to identify conditions more conducive to success of reduction-based U stabilization. Our current research targets several… more
Date: April 19, 2007
Creator: Tokunaga, Tetsu; Wan, Jiamin; Kim, Yongman; Daly, Rebecca; Brodie, Eoin; Firestone, Mary et al.
Partner: UNT Libraries Government Documents Department

Molecular-Level Investigations of Nucleation Mechanisms and Kinetics of Formation of Environmental Nanoparticles

Description: Environmental nanoparticles are often poorly-crystalline or metastable structures, whose kinetics of formation and growth are poorly understood. Further, the sorption or growth of nanoparticles on mineral surfaces may control the mineral surface's reactivity and modify its ability to influence contaminant transport. Due to the characteristic length scale, a holistic understanding of the nucleation mechanisms and kinetics of nanoparticle formation on mineral surfaces is difficult to achieve with… more
Date: April 19, 2007
Creator: Jun, Young-Shin & Waychunas, Glenn A.
Partner: UNT Libraries Government Documents Department

[Pride Texas 2008 poster]

Description: Poster for Pride Texas 2008, held in Austin, that advertises events and acknowledges sponsors. 500 copies of this poster were placed throughout Austin, according to the label on the CD containing the poster's born-digital file. The theme of Pride Texas 2008 was "Building Community."
Date: 2008
Creator: Equality Texas
Partner: UNT Libraries Special Collections

[Pride Texas Festival 2008 advance tickets poster]

Description: Poster advertising advance tickets for the 2008 Pride Texas Festival in Austin. The names of musical performers and sponsors are given. The theme of Pride Texas 2008 was "Building Community." According to the digital file title, this poster was hung at the following businesses: BookWoman, Tapelenders, Lobo, Waterloo Records, and all Washington Mutual locations in Austin.
Date: 2008
Creator: Equality Texas
Partner: UNT Libraries Special Collections

[Pilotdrift poster]

Description: Poster advertising an album release by the band Pilotdrift, of Texarkana, Texas. Poster features a red monochromatic illustration of a science fiction style landscape and floating spheres, with the band name and album name, 'Water Sphere', printed across the image. The band website, as well as that of Good Records who released the album, is printed in white at the bottom of the poster.
Date: 2005
Partner: UNT Music Library
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