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[Dallas poster from the March On Washington (signature close up)]

Detail view of part of a poster from the 1993 March on Washington for Lesbian, Gay and Bi Equal Rights and Liberation. Part of the "ALL" from the word "Dallas" written down the center of the poster is visible, with signatures written around the letters.
Date: April 1993
Creator: unknown
System: The UNT Digital Library

[Dallas poster from the March On Washington]

Poster from the 1993 March on Washington for Lesbian, Gay and Bi Equal Rights and Liberation. There is a pink pegasus at the top of the poster, above the word "Dallas" written down the center of the poster with the text for the March at the bottom. The poster has signatures around the text and is set on a brown mat.
Date: April 1993
Creator: unknown
System: The UNT Digital Library

[Dallas poster from the March On Washington]

Poster from the 1993 March on Washington for Lesbian, Gay and Bi Equal Rights and Liberation. There is a pink pegasus at the top of the poster, above the word "Dallas" written down the center of the poster with the text for the March at the bottom. The poster has signatures around the text.
Date: April 1993
Creator: unknown
System: The UNT Digital Library

[Dallas poster from the March On Washington (stamp close up)]

Detail view of the lower-right part of a "Dallas" poster. There is a pink circle with the text "I was COUNTED! April 25th, 1993 March on Washington for Lesbian, Gay and Bi Equal Rights and Liberation." "1993" is written below the circle and signatures are partially visible on the poster background.
Date: April 1993
Creator: unknown
System: The UNT Digital Library

[Dallas poster from the March On Washington (full view)]

Poster from the 1993 March on Washington for Lesbian, Gay and Bi Equal Rights and Liberation. There is a pink pegasus at the top of the poster, above the word "Dallas" written down the center of the poster with the text for the March at the bottom. The poster has signatures around the text and is framed on a brown mat.
Date: April 1993
Creator: unknown
System: The UNT Digital Library

Legacy of Stalinism in Modern Russia: Historical Trauma, Memory and Forgetting

This poster presentation discusses research on a transformative instructional initiative on globalizing curriculum. The project involved students learning about the legacy of Stalinism in modern Russia and connecting students to their virtual peers in Russia via the internet.
Date: April 12, 2013
Creator: Velikanova, Olga V.
System: The UNT Digital Library

[Dallas Gay Political Caucus Flyer]

Flyer for a roller skating party hosted by the Dallas Gay Political Caucus on May 18th, 1977 to support the Miami Gay Community after public remarks by Anita Bryant, who was known at the time for her anti-gay statements.
Date: 1977-04~
Creator: Dallas Gay Political Caucus
System: The UNT Digital Library

Unauthorized Immigration

This poster introduces the faculty lecture series UNT Speaks Out on Unauthorized Immigration. This series features Dr. Valerie Martinez-Ebers, professor of political science, Dr. David Molina, professor of economics and interim director of UNT's Immigrant Research and Policy Center, Dr. Mariela Nuñez-Janes, professor of anthropology, Shaun Chapa, a graduate student in the anthropology department.
Date: April 2011
Creator: Mondragon-Becker, Antonio
System: The UNT Digital Library

Kinetic Controls on the Desorption/Dissolution of Sorbed U(VI) and Their Influence on Reactive Transport

None
Date: April 19, 2007
Creator: Zachara, J. M.; Liu, C.; Qafoku, N.; McKinley, J. P.; Davis, J. A.; Stoliker, D. et al.
System: The UNT Digital Library

Development of Modeling Methods and Tools for Predicting Coupled Reactive Transport Processes in Porous Media at Multiple Scales

None
Date: April 19, 2007
Creator: Kanel, S. R.; Loganathan, V. A.; Jeppu, G.; Kumar, A.; Srinivasan, V.; Radu, T. et al.
System: The UNT Digital Library

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

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 in terms of average concentrations) and actual processes (controlled by local concentrations). At the field scale, this results in apparent scale-dependence of model parameters and inability to utilize laboratory parameters in field models. Accordingly, most field modeling efforts are restricted to empirical estimation of model parameters by fitting to field observations, which renders extrapolation of model predictions beyond fitted conditions unreliable. The objective of this project is to develop a theoretical and computational framework for (1) connecting models of coupled reactive transport from pore-scale processes to field-scale bioremediation through a hierarchy of models that maintain crucial information from the smaller scales at the larger scales; and (2) quantifying the uncertainty that is introduced by both the upscaling process and uncertainty in physical parameters. One of the challenges of addressing scale-dependent effects of coupled processes in …
Date: April 19, 2007
Creator: Scheibe, Tim; Tartakovsky, Alexandre; Wood, Brian & Seymour, Joe
System: The UNT Digital Library

Applying EMSL Capabilities to Biogeochemistry and Environmental Research

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 peer-reviewed proposal basis and are offered at no cost if research results are shared in the open literature. Researchers are encouraged to submit a proposal centered around one of EMSL's four Science Themes, which represent growing areas of research: (1) Geochemistry/Biogeochemistry and Subsurface Science; (2) Atmospheric Aerosol Chemistry; (3) Biological Interactions and Dynamics; and (4) Science of Interfacial Phenomena. To learn more about EMSL, visit www.emsl.pnl.gov.
Date: April 19, 2007
Creator: Felmy, Andy
System: The UNT Digital Library

Synthesis of Goethite-Coated Sand and Analysis of its Interactions with Uranium

None
Date: April 19, 2007
Creator: Loganathan, Vijay A.; Kanel, Sushil R.; Barnett, Mark O. & Clement, and T. Prabhakar
System: The UNT Digital Library

Changes in Microbial Community Structure During Biostimulation for Uranium Reduction at Different Levels of Resolution

This poster describes the Changes in Microbial Community Structure During Biostimulation for Uranium Reduction at Different Levels of Resolution
Date: April 19, 2007
Creator: Hwang, C.; Wu, W.-M.; Gentry, T.J.; Corbin, G.; Carley, J.; Carroll, S.L. et al.
System: The UNT Digital Library

Coupled Processes Influencing the Transport of Uranium over Multiple Scales

None
Date: April 19, 2007
Creator: Mayes, Melanie A.; Tang, Guoping; Parker, Jack C.; Perfect, Ed & van den Berg, Elmer
System: The UNT Digital Library

Influence of Wetting and Mass Transfer Properties of Organic Chemical Mixtures in Vadose Zone Materials on Groundwater Contamination by Nonaqueous Phase Liquids

None
Date: April 19, 2007
Creator: Werth, Charles; Valocchi, Albert; Yoon, Hongkyu; Nellis, Scott; Prescod, Garvin & Oostrom, Mart
System: The UNT Digital Library

Biogeochemical Mechanisms Controlling Reduced Radionuclide Particle Properties and Stability

None
Date: April 19, 2007
Creator: Marshall, M.J.; Beliaev, A.S.; Fredrickson, J.K. & Zachara, J.M
System: The UNT Digital Library

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

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 work on these complex problems at multiple length scales and to compile and synthesize the kinetic data. Development of the human resources capable of translating molecular-scale information into parameters that are applicable in real world, field-scale problems of environmental kinetics is a major and relatively unique objective of the Institute's efforts. The EMSI team is a partnership among 10 faculty at The Pennsylvania State University (funded by the National Science Foundation Divisions of Chemistry and Earth Sciences), one faculty member at Juniata College, one faculty member at the University of Florida, and four researchers drawn from Los Alamos National Laboratory, Pacific Northwest National Laboratory, and Lawrence Berkeley National Laboratory (funded by the Department of Energy Division of Environmental Remediation Sciences). Interactions among the applied and academic scientists drives research approaches …
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.
System: The UNT Digital Library

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

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 substrate is added to the subsurface or when environmental conditions change.
Date: April 19, 2007
Creator: Istok, Jack; Park, Melora; McKinley, James; Liu, Chongxuan; Krumholz, Lee; Spain, Anne et al.
System: The UNT Digital Library

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

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 contaminants at Hanford is difficult due to the presence of multiple potential sources within small areas, the long history of activities, the range of disposal methods, and the continuing evolution of the hydrological system. Observations often do not conform to simple models, and cannot be adequately understood with standard characterization approaches, even though the characterization activities are quite extensive. One of our objectives is to test the value of adding isotopic techniques to the characterization program, which has the immediate potential benefit of addressing specific remediation issues, but more importantly, it allows us to study fundamental processes at the scale and in the medium where they need to be understood. Here we focus on two recent studies at the waste management area (WMA) T-TX-TY, which …
Date: April 19, 2007
Creator: DePaolo, Donald J.; Christensen, John N.; Conrad, Mark E. & Dresel, and P. Evan
System: The UNT Digital Library

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

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 species form they will increase the solubility and resultant mobility from contamination sources. There is evidence that in both marine environments and brines substantial fractions of the plutonium in solution is present as hexavalent plutonyl, PuO2 2+.
Date: April 19, 2007
Creator: Boukhalfa, Hakim; Icopini, Gary A.; Reilly, Sean D. & Neu, Mary P.
System: The UNT Digital Library

Multi-Scale Mass Transfer Processes Controlling Natural Attenuation and Engineered Remediation: An IFC Focused on Hanford’s 300 Area Uranium Plume

None
Date: April 19, 2007
Creator: Zachara, J.; Freshley, M.; DePaolo, D.; Fredrickson, J.; Haggerty, R.; Kent, D. et al.
System: The UNT Digital Library

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

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 of these issues including: (1) effects of organic carbon (OC) forms and supply rates on stability of bioreduced U, (2) the roles of Fe(III)- and Mn(III,IV)-oxides as potential U oxidants in sediments, and (3) microbial community changes in relation to U redox changes. These issues were identified in our previous study on U bioreduction and reoxidation (Wan et al., 2005). Most of our studies are being conducted on historically U-contaminated sediments from Area 2 of the Field Research Center, Oak Ridge National Laboratory, in flow-through columns simulating in-situ field remediation.
Date: April 19, 2007
Creator: Tokunaga, Tetsu; Wan, Jiamin; Kim, Yongman; Daly, Rebecca; Brodie, Eoin; Firestone, Mary et al.
System: The UNT Digital Library

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

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 traditional methodology. In this work, our intent is to determine the molecular nature of nucleation on surfaces, the kinetics of surface nucleation and growth, and the effect of crystal surface topology using new synchrotron-based techniques. We have approached these objectives by: (1) combining state-of-the-art crystal-truncation rod diffraction (CTR) and grazing incidence x-ray absorption fine structure spectroscopy (GIXAS) techniques to investigate the three-dimensional molecular-scale geometry of silicate monomer sorption on the r-plane of hematite; and (2) developing a new grazing-incidence small angle x-ray scattering (GISAXS) setup at SSRL (0.08 nm{sup -1} < q < 8 nm{sup -1}) to explore the initial development of environmental nanoparticles on various mineral surfaces. This study also includes complementary techniques such as atomic force microscopy (AFM), bulk SAXS, dynamic light scattering (DLS), XRD, and TEM.
Date: April 19, 2007
Creator: Jun, Young-Shin & Waychunas, Glenn A.
System: The UNT Digital Library