9,633 research outputs found
In Situ Immobilization of Uranium in Structured Porous Media via Biomineralization at the Fracture/Matrix Interface – Subproject to Co-PI Eric E. Roden
No full textAlthough the biogeochemical processes underlying in situ bioremediation technologies are increasingly well understood, field-scale heterogeneity (both physical and biogeochemical) remains a major obstacle to successful field-scale implementation. In particular, slow release of contamination from low-permeability regions (primarily by diffusive/dispersive mass transfer) can hinder the effectiveness of remediation. The research described in this report was conducted in conjunction with a project entitled “In Situ Immobilization of Uranium in Structured Porous Media via Biomineralization at the Fracture/Matrix Interface”, which was funded through the Field Research element of the former NABIR Program (now the Environmental Remediation Sciences Program) within the Office of Biological and Environmental Research. Dr. Timothy Scheibe (Pacific Northwest National Laboratory) was the overall PI/PD for the project, which included Scott Brooks (Oak Ridge National Laboratory) and Eric Roden (formerly at The University of Alabama, now at the University of Wisconsin) as separately-funded co-PIs. The overall goal of the project was to evaluate strategies that target bioremediation at interfaces between high- and low-permeability regions of an aquifer in order to minimize the rate of contaminant transfer into high-permeability/high fluid flow zones. The research was conducted at the Area 2 site of the Field Research Center (FRC) at Oak Ridge National Laboratory (ORNL). Area 2 is a shallow pathway for migration of contaminated groundwater to seeps in the upper reach of Bear Creek at ORNL, mainly through a ca. 1 m thick layer of gravel located 4-5 m below the ground surface. Hydrological tracer studies indicate that the gravel layer receives input of uranium from both upstream sources and from diffusive mass transfer out of highly contaminated fill and saprolite materials above and below the gravel layer. We sought to test the hypothesis that injection of electron donor into this layer would induce formation of a redox barrier in the less conductive materials above and below the gravel, resulting in decreased mass transfer of uranium out these materials and attendant declines in groundwater U(VI) concentration. Details regarding the planning, execution, and results of the in situ biostimulation experiment will be provided in separate peer-reviewed publications by the project PIs and colleagues. This report summarizes research activities conducted at The University of Alabama (2002-2005) and the University of Wisconsin (2005-2007) in support of the field experiment, which included (1) chemical and microbiological characterization of sediment cores from Area 2; (2) sediment slurry experiments with Area 2 materials which evaluated the biogeochemical response to ethanol amendment and the potential for U(VI) reduction; (3) analysis of the response of groundwater microbial communities to in situ biostimulation. In addition, biogeochemical reaction models of microbial metabolism in ethanol-stimulated sediments, developed based on sediment slurry experiments, are described
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Final Scientific/Technical Report – DE-FG02-06ER64172 – Reaction-Based Reactive Transport Modeling of Iron Reduction and Uranium Immobilization at Area 2 of the NABIR Field Research Center – Subproject to Co-PI Eric E. Roden
No full textThis report summarizes research conducted in conjunction with a project entitled “Reaction-Based Reactive Transport Modeling of Iron Reduction and Uranium Immobilization at Area 2 of the NABIR Field Research Center”, which was funded through the Integrative Studies Element of the former NABIR Program (now the Environmental Remediation Sciences Program) within the Office of Biological and Environmental Research. Dr. William Burgos (The Pennsylvania State University) was the overall PI/PD for the project, which included Brian Dempsey (Penn State), Gour-Tsyh (George) Yeh (Central Florida University), and Eric Roden (formerly at The University of Alabama, now at the University of Wisconsin) as separately-funded co-PIs. The project focused on development of a mechanistic understanding and quantitative models of coupled Fe(III)/U(VI) reduction in FRC Area 2 sediments. The work builds on our previous studies of microbial Fe(III) and U(VI) reduction, and was directly aligned with the Scheibe et al. ORNL FRC Field Project at Area 2. Area 2 is a shallow pathway for migration of contaminated groundwater to seeps in the upper reach of Bear Creek at ORNL, mainly through a ca. 1 m thick layer of gravel located 4-5 m below the ground surface. The gravel layer is sandwiched between an overlying layer of disturbed fill material, and 2-3 m of undisturbed shale saprolite derived from the underlying Nolichucky Shale bedrock. The fill was put in place when contaminated soils were excavated and replaced by native saprolite from an uncontaminated area within Bear Creek Valley; the gravel layer was presumably installed prior to addition of the fill in order to provide a stable surface for the operation of heavy machinery. The undisturbed saprolite is highly weathered bedrock that has unconsolidated character but retains much of the bedding and fracture structure of the parent rock (shale with interbedded limestone). Hydrological tracer studies conducted during the Scheibe et al. field project indicate that the gravel layer receives input of uranium from both upstream sources and from diffusive mass transfer out of highly contaminated fill and saprolite materials above and below the gravel layer. This research sought to examine biogeochemical processes likely to take place in the less conductive materials above and below the gravel during the in situ ethanol biostimulation experiment conducted at Area 2 during 2005-2006. The in situ experiment in turn examined the hypothesis that injection of electron donor into this layer would induce formation of a redox barrier in the less conductive materials, resulting in decreased mass transfer of uranium out these materials and attendant declines in groundwater U(VI) concentration. Our research was directed toward the following three major objectives relevant to formation of this redox barrier: (1) elucidate the kinetics and mechanisms of reduction of solid-phase Fe(III) and U(VI) in Area 2 sediments; (2) evaluate the potential for long-term sustained U(IV) reductive immobilization in Area 2 sediments; (3) numerically simulate the suite of hydrobiogeochemical processes occurring in experimental systems so as to facilitate modeling of in situ U(IV) immobilization at the field-scale
ROSENTHAL, Eric Inventory of documents
No full textCOVERAGE 1904; 1 File; 011 metre.Private papers of Eric Rosenthal, author, journalist and broadcaster
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Reaction-based reactive transport modeling of Fe(III)
No full textThis research project (started Fall 2004) was funded by a grant to Argonne National Laboratory, The Pennsylvania State University, and The University of Alabama in the Integrative Studies Element of the NABIR Program (DE-FG04-ER63914/63915/63196). Dr. Eric Roden, formerly at The University of Alabama, is now at the University of Wisconsin, Madison. Our project focuses on the development of a mechanistic understanding and quantitative models of coupled Fe(III)/U(VI) reduction in FRC Area 2 sediments. This work builds on our previous studies of microbial Fe(III) and U(VI) reduction, and is directly aligned with the Scheibe et al. NABIR FRC Field Project at Area 2
Nonalcoholic Fatty Liver Disease and Cardiovascular Disease
No full textWatch a video presentation of this article Answer questions and earn CME
tritrophic-dispersal-model: Code used for creating figures for "Non-hierarchical dispersal promotes stability and resilience in a tri-trophic metacommunity"
No full text<p>This is the commented code used for creating figures for the paper. Any questions regarding the code should be directed to the corresponding author and repository owner (Eric Pedersen). </p>
Eric Velazquez Spanish Language Picture Book Award 2022 Acceptance Speech
No full textAuthor Eric Velazquez gives his Silver Medal acceptance speech for Pulpo Guisado (Holiday House)https://educate.bankstreet.edu/spanishlanguageaward/1001/thumbnail.jp
Eric C. Lincoln, Professor of Sociology and Religion, 1971
No full textThis is an interview with Eric C. Lincoln. Eric was a Professor of Sociology and religion, Union Theological Seminary and author of many books and articles on Negro history. In this recording the contributors discuss local memphis politics, sociology, and race relations compared to that of other cities in the South and the rest of the country
Interview with Eric Bentley, author, drama critic, and playwright
No full textDistinguished drama critic and Bertolt Brecht scholar, Eric Bentley is interviewed by WTMJ-TV host Jim Peck and John B. Fuegi, associate professor of Comparative Literature. Bentley recalls his association with Brecht, the critical and creative aspects of literature, and his interest in writing plays for the theater.GrayscaleSoun
Dr. Eric Yellin – Faculty Author Interview
No full textDr. Eric Yellin, Associate Professor of History and American Studies discusses his new book, Racism in the Nation’s Service: Government Workers and the Color Line in Woodrow Wilson’s America, published recently by the University of North Carolina Press. In this book, Dr. Yellin argues that President Wilson’s administration successfully segregated the federal government in the age of progressive politics. He investigates how the enactment of the segregation policy imposed a color line on American opportunity and implicated Washington in the economic limitation of African Americans for decades to com
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