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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

Alternations of Structure and Functional Activity of Below Ground Microbial Communities at Elevated Atmospheric Carbon Dioxide

Description: The global atmospheric concentration of CO2 has increased by more than 30percent since the industrial revolution. Although the stimulating effects of elevated CO2 (eCO2) on plant growth and primary productivity have been well studied, its influences on belowground microbial communities are poorly understood and controversial. In this study, we showed a significant change in the structure and functional potential of soil microbial communities at eCO2 in a grassland ecosystem, the BioCON (Biodive… more
Date: May 17, 2010
Creator: He, Zhili; Xu, Meiying; Deng, Ye; Kang, Sanghoon; Wu, Liyou; Van Nostrand, Joy D. et al.
Partner: UNT Libraries Government Documents Department

HuMiChip: Development of a Functional Gene Array for the Study of Human Microbiomes

Description: Microbiomes play very important roles in terms of nutrition, health and disease by interacting with their hosts. Based on sequence data currently available in public domains, we have developed a functional gene array to monitor both organismal and functional gene profiles of normal microbiota in human and mouse hosts, and such an array is called human and mouse microbiota array, HMM-Chip. First, seed sequences were identified from KEGG databases, and used to construct a seed database (seedDB) c… more
Date: May 17, 2010
Creator: Tu, Q.; Deng, Ye; Lin, Lu; Hemme, Chris L.; He, Zhili & Zhou, Jizhong
Partner: UNT Libraries Government Documents Department

Durability of Polymeric Encapsulation Materials for Concentrating Photovoltaic Systems [Poster]

Description: Polymeric encapsulation materials are typically used in concentrating photovoltaic (CPV) modules to protect the cell from the field environment. Because it is physically located adjacent to the cell, the encapsulation is exposed to a high optical flux, often including light in the ultraviolet (UV) and infrared (IR) wavelengths. The durability of encapsulants used in CPV modules is critical to the technology, but is presently not well understood. This work seeks to identify the appropriate mater… more
Date: February 1, 2011
Creator: Miller, D. C.; Kempe, M. D.; Araki, K.; Kennedy, C. E. & Kurtz, S. R.
Partner: UNT Libraries Government Documents Department

Regulon inference without arbitrary thresholds: three levels of sensitivity

Description: Reconstruction of transcriptional regulatory networks is one of the major challenges facing the bioinformatics community in view of constantly growing number of complete genomes. The comparative genomics approach has been successfully used for the analysis of the transcriptional regulation of many metabolic systems in various bacteria taxa. The key step in this approach is given a position weight matrix, find an optimal threshold for the search of potential binding sites in genomes. In our prev… more
Date: November 15, 2010
Creator: Dubchak, Pavel Novichkov, Elena Stavrovskaya, Dmitry Rodionov, Andrey Mironov, Inna; Rodionov, Dmitry; Mironov, Andrey; Dubchak, Inna & Novichkov, P.S.
Partner: UNT Libraries Government Documents Department
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