Next Generation Bipolar Plates for Automotive PEM Fuel Cells (open access)

Next Generation Bipolar Plates for Automotive PEM Fuel Cells

The results of a successful U.S. Department of Energy (DoE) funded two-year $2.9 MM program lead by GrafTech International Inc. (GrafTech) are reported and summarized. The program goal was to develop the next generation of high temperature proton exchange membrane (PEM) fuel cell bipolar plates for use in transportation fuel cell applications operating at temperatures up to 120 °C. The bipolar plate composite developed during the program is based on GrafTech’s GRAFCELL resin impregnated flexible graphite technology and makes use of a high temperature Huntsman Advanced Materials resin system which extends the upper use temperature of the composite to the DoE target. High temperature performance of the new composite is achieved with the added benefit of improvements in strength, modulus, and dimensional stability over the incumbent resin systems. Other physical properties, including thermal and electrical conductivity of the new composite are identical to or not adversely affected by the new resin system. Using the new bipolar plate composite system, machined plates were fabricated and tested in high temperature single-cell fuel cells operating at 120 °C for over 1100 hours by Case Western Reserve University. Final verification of performance was done on embossed full-size plates which were fabricated and glued into …
Date: April 15, 2010
Creator: Adrianowycz, Orest; Norley, Julian; Stuart, David J.; Flaherty, David; Wayne, Ryan; Williams, Warren et al.
Object Type: Report
System: The UNT Digital Library
Optimization of the Transport Shield for Neutrinoless Double Beta-decay Enriched Germanium (open access)

Optimization of the Transport Shield for Neutrinoless Double Beta-decay Enriched Germanium

This document presents results of an investigation of the material and geometry choice for the transport shield of germanium, the active detector material used in 76Ge neutrinoless double beta decay searches. The objective of this work is to select the optimal material and geometry to minimize cosmogenic production of radioactive isotopes in the germanium material. The design of such a shield is based on the calculation of the cosmogenic production rate of isotopes that are known to cause interfering backgrounds in 76Ge neutrinoless double beta decay searches.
Date: April 15, 2012
Creator: Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Orrell, John L.; Reid, Douglas J. & Fast, James E.
Object Type: Report
System: The UNT Digital Library
Helium measurements of pore-fluids obtained from SAFOD drillcore (open access)

Helium measurements of pore-fluids obtained from SAFOD drillcore

{sup 4}He accumulated in fluids is a well established geochemical tracer used to study crustal fluid dynamics. Direct fluid samples are not always collectable; therefore, a method to extract rare gases from matrix fluids of whole rocks by diffusion has been adapted. Helium was measured on matrix fluids extracted from sandstones and mudstones recovered during the San Andreas Fault Observatory at Depth (SAFOD) drilling in California, USA. Samples were typically collected as subcores or from drillcore fragments. Helium concentration and isotope ratios were measured 4-6 times on each sample, and indicate a bulk {sup 4}He diffusion coefficient of 3.5 {+-} 1.3 x 10{sup -8} cm{sup 2}s{sup -1} at 21 C, compared to previously published diffusion coefficients of 1.2 x 10{sup -18} cm{sup 2}s{sup -1} (21 C) to 3.0 x 10{sup -15} cm{sup 2}s{sup -1} (150 C) in the sands and clays. Correcting the diffusion coefficient of {sup 4}He{sub water} for matrix porosity ({approx}3%) and tortuosity ({approx}6-13) produces effective diffusion coefficients of 1 x 10{sup -8} cm{sup 2}s{sup -1} (21 C) and 1 x 10{sup -7} (120 C), effectively isolating pore fluid {sup 4}He from the {sup 4}He contained in the rock matrix. Model calculations indicate that <6% of helium initially …
Date: April 15, 2010
Creator: Ali, S.; Stute, M.; Torgersen, T.; Winckler, G. & Kennedy, B.M.
Object Type: Article
System: The UNT Digital Library
Distributed H{sub 2} Supply for Fuel Cell Utility Vehicles Year 6 - Activity 3.5 - Development fo a National Center for Hydrogen Technology (open access)

Distributed H{sub 2} Supply for Fuel Cell Utility Vehicles Year 6 - Activity 3.5 - Development fo a National Center for Hydrogen Technology

The Energy & Environmental Research Center (EERC) has developed a high-pressure hydrogen production system that reforms a liquid organic feedstock and water at operating pressures up to 800 bar (~12,000 psig). The advantages of this system include the elimination of energy-intensive hydrogen compression, a smaller process footprint, and the elimination of gaseous or liquid hydrogen transport. This system could also potentially enable distributed hydrogen production from centralized coal. Processes have been investigated to gasify coal and then convert the syngas into alcohol or alkanes. These alcohols and alkanes could then be easily transported in bulk to distributed high-pressure water-reforming (HPWR)-based systems to deliver hydrogen economically. The intent of this activity was to utilize the EERC’s existing HPWR hydrogen production process, previously designed and constructed in a prior project phase, as a basis to improve operational and production performance of an existing demonstration unit. Parameters to be pursued included higher hydrogen delivery pressure, higher hydrogen production rates, and the ability to refill within a 5-minute time frame.
Date: April 15, 2012
Creator: Almlie, Jay
Object Type: Report
System: The UNT Digital Library
Muon-induced backgrounds in the CUORICINO experiment (open access)

Muon-induced backgrounds in the CUORICINO experiment

To better understand the contribution of cosmic ray muons to the CUORICINO background, ten plastic scintillator detectors were installed at the CUORICINO siteand operated during the final 3 months of the experiment. From these measurements, an upper limit of 0.0021 counts/(keV.kg.yr) (95percent c.l.) was obtained on the cosmicray induced background in the neutrinoless double beta decay region of interest. The measurements were also compared to Geant4 simulations.
Date: April 15, 2010
Creator: Andreotti, E.; Arnaboldi, C.; Avignone, F. T. III; Balata, M.; Bandac, I.; Barucci, M. et al.
Object Type: Article
System: The UNT Digital Library
Ultra-High Efficiency and Low-Emissions Combustion Technology for Manufacturing Industries (open access)

Ultra-High Efficiency and Low-Emissions Combustion Technology for Manufacturing Industries

The purpose of this research was to develop and test a transformational combustion technology for high temperature furnaces to reduce the energy intensity and carbon footprint of U.S. manufacturing industries such as steel, aluminum, glass, metal casting, and petroleum refining. A new technology based on internal and/or external Flue Gas Recirculation (FGR) along with significant enhancement in flame radiation was developed. It produces "Radiative Flameless Combustion (RFC)" and offers tremendous energy efficiency and pollutant reduction benefits over and above the now popular "flameless combustion." It will reduce the energy intensity (or fuel consumption per unit system output) by more than 50% and double the furnace productivity while significantly reducing pollutants and greenhouse gas emissions (10^3 times reduction in NOx and 10 times reduction in CO & hydrocarbons and 3 times reduction in CO2). Product quality improvements are also expected due to uniform radiation, as well as, reduction in scale/dross formation is expected because of non-oxidative atmosphere. RFC is inexpensive, easy to implement, and it was successfully tested in a laboratory-scale furnace at the University of Michigan during the course of this work. A first-ever theory with gas and particulate radiation was also developed. Numerical programs were also written to design …
Date: April 15, 2013
Creator: Atreya, Arvind
Object Type: Report
System: The UNT Digital Library
Trends in Discretionary Spending (open access)

Trends in Discretionary Spending

This report discusses recent trends in discretionary spending. Topics examined include fiscal policy in the wake of the recession, discretionary spending limits reimposed in 2011, the FY2013 sequestration, long term trends, and security spending.
Date: April 15, 2013
Creator: Austin, D. Andrew
Object Type: Report
System: The UNT Digital Library
Mexico’s Drug Trafficking Organizations: Source and Scope of the Violence (open access)

Mexico’s Drug Trafficking Organizations: Source and Scope of the Violence

This report details drug trafficking in Mexico and how it has altered. It also delves into the violence of the drug organizations, and depicts possible ways to reduce the violence.
Date: April 15, 2013
Creator: Beittel, June S.
Object Type: Report
System: The UNT Digital Library
The U.N. Convention on the Elimination of All Forms of Discrimination Against Women (CEDAW): Issues in the U.S. Ratification Debate (open access)

The U.N. Convention on the Elimination of All Forms of Discrimination Against Women (CEDAW): Issues in the U.S. Ratification Debate

This report provides an overview of the Convention on the Elimination of All Forms of Discrimination Against Women (CEDAW) and describes its background, objectives, and structure, including the role of the Convention's monitoring body, the CEDAW Committee. It examines U.S. policy and issues in the U.S. ratification debate, including the Convention's possible impact on U.S. sovereignty, its effectiveness in combating discrimination, and its role as an instrument of U.S. foreign policy.
Date: April 15, 2011
Creator: Blanchfield, Luisa
Object Type: Report
System: The UNT Digital Library
Recent Developments in Dynamic Transmission Electron Microscopy (open access)

Recent Developments in Dynamic Transmission Electron Microscopy

None
Date: April 15, 2011
Creator: Browning, N D; Bonds, M A; Campbell, G H; Evans, J E; LaGrange, T; Jungjohann, K L et al.
Object Type: Article
System: The UNT Digital Library
Salaries of Members of Congress: Congressional Votes, 1990-2015 (open access)

Salaries of Members of Congress: Congressional Votes, 1990-2015

This report contains information on actions taken affecting each pay year since the establishment of the Ethics Reform Act adjustment procedure. It also provides information on other floor action related to pay for Members of Congress.
Date: April 15, 2015
Creator: Brudnik, Ida A.
Object Type: Report
System: The UNT Digital Library
DOE Computer Graphics Forum 2013 Site Survey (open access)

DOE Computer Graphics Forum 2013 Site Survey

None
Date: April 15, 2013
Creator: Brugger, E S; Springmeyer, R R & Laney, D E
Object Type: Report
System: The UNT Digital Library
Effects of Radiation from Fukushima Daiichi on the U.S. Marine Environment (open access)

Effects of Radiation from Fukushima Daiichi on the U.S. Marine Environment

The massive Tohoku earthquake and tsunami of March 11, 2011, caused extensive damage in northeastern Japan, including damage to the Fukushima Dai-ichi nuclear power installation, which resulted in the release of radiation. This report discusses concerns which have arisen about the potential effects of this released radiation on the U.S. marine environment and resources.
Date: April 15, 2011
Creator: Buck, Eugene H. & Upton, Harold F.
Object Type: Report
System: The UNT Digital Library
Asian Carp and the Great Lakes Region (open access)

Asian Carp and the Great Lakes Region

Four species of non-indigenous Asian carp are expanding their range in U.S. waterways, resulting in a variety of concerns and problems. This report details the environmental and economic threats from this invasion, as well as ways to combat the spread of Asian carp in U.S. water.
Date: April 15, 2011
Creator: Buck, Eugene H.; Upton, Harold F.; Stern, Charles V. & Brown, Cynthia
Object Type: Report
System: The UNT Digital Library
Use of immunomagnetic separation for the detection of Desulfovibrio vulgaris from environmental samples (open access)

Use of immunomagnetic separation for the detection of Desulfovibrio vulgaris from environmental samples

Immunomagnetic separation (IMS) has proved highly efficient for recovering microorganisms from heterogeneous samples. Current investigation targeted the separation of viable cells of the sulfate-reducing bacterium, Desulfovibrio vulgaris. Streptavidin-coupled paramagnetic beads and biotin labeled antibodies raised against surface antigens of this microorganism were used to capture D. vulgaris cells in both bioreactor grown laboratory samples and from extremely low-biomass environmental soil and subsurface drilling samples. Initial studies on detection, recovery efficiency and viability for IMS were performed with laboratory grown D. vulgaris cells using various cell densities. Efficiency of cell isolation and recovery (i.e., release of the microbial cells from the beads following separation) was followed by microscopic imaging and acridine orange direct counts (AODC). Excellent recovery efficiency encouraged the use of IMS to capture Desulfovibrio spp. cells from low-biomass environmental samples. The environmental samples were obtained from a radionuclide-contaminated site in Germany and the chromium (VI)-contaminated Hanford site, an ongoing bioremediation project of the U.S. Department of Energy. Field deployable IMS technology may greatly facilitate environmental sampling and bioremediation process monitoring and enable transcriptomics and proteomics/metabolomics-based studies directly on cells collected from the field.
Date: April 15, 2011
Creator: Chakraborty, R.; Hazen, T. C.; Joyner, D. C.; Kusel, K.; Singer, M. E.; Sitte, J. et al.
Object Type: Article
System: The UNT Digital Library
Allocation of Wastewater Treatment Assistance: Formula and Other Changes (open access)

Allocation of Wastewater Treatment Assistance: Formula and Other Changes

This report consists of allocation of wastewater treatment assistance: Formula and Other Changes.
Date: April 15, 2015
Creator: Copeland, Claudia
Object Type: Report
System: The UNT Digital Library
Final Report on ``Theories of Strong Electron Correlations in Molecules and Solids’’ - DE-FG02-97ER45640 (open access)

Final Report on ``Theories of Strong Electron Correlations in Molecules and Solids’’ - DE-FG02-97ER45640

The PI led theoretical studies of correlated hybridization in transition metal complexes, compounds, and molecules, and of electron transport in DNA associated with nanoelectronic conformations attached to gold electrodes and in the presence of DNA repair proteins.
Date: April 15, 2013
Creator: Cox, Daniel L.
Object Type: Report
System: The UNT Digital Library
Optimal nitrogen application rates for three intensively-managed hardwood tree species in the southeastern USA. (open access)

Optimal nitrogen application rates for three intensively-managed hardwood tree species in the southeastern USA.

Forest production can be limited by nutrient and water availability, and tree species are expected to respond differently to fertilization and irrigation. Despite these common expectations, multi-species comparisons are rare, especially ones implementing a range of fertilization rates crossed with irrigation. This study compares the response of three forest hardwood species to numerous nitrogen (N) fertilization levels and water availability using a novel non-replicated technique. A range of N levels was included to determine how N affected the growth response curve, and statistical procedures for comparing these non-linear response functions are presented. We used growth and yield data to calculate the Land Expectation Value (LEV) for these intensive management treatments, and to determine the optimal growing conditions (accounting for tree productivity and grower expenses). To accomplish these objectives, we used a series of cottonwood, sycamore, and sweetgum plots that received a range of N fertilization with or without irrigation. Regression is an economical approach to define treatment responses in large-scale experiments, and we recommend >3 treatment levels so the response of any single plot does not disproportionally influence the line. The non-replicated plots showed a strong positive N response below 150 kg N ha -1 yr -1, beyond which little …
Date: April 15, 2013
Creator: Coyle, David; Aubrey, Doug P.; Siry, Jacek P.; Volfovicz-Leon, Roberto R. & Coleman, Mark D.
Object Type: Article
System: The UNT Digital Library
Shape-selective catalysts for Fischer-Tropsch chemistry : atomic layer deposition of active catalytic metals. Activity report : January 1, 2005 - September 30, 2005. (open access)

Shape-selective catalysts for Fischer-Tropsch chemistry : atomic layer deposition of active catalytic metals. Activity report : January 1, 2005 - September 30, 2005.

Argonne National Laboratory is carrying out a research program to create, prepare, and evaluate catalysts to promote Fischer-Tropsch (FT) chemistry - specifically, the reaction of hydrogen with carbon monoxide to form long-chain hydrocarbons. In addition to needing high activity, it is desirable that the catalysts have high selectivity and stability with respect to both mechanical strength and aging properties. The broad goal is to produce diesel fraction components and avoiding excess yields of both light hydrocarbons and heavy waxes. Originally the goal was to prepare shape-selective catalysts that would limit the formation of long-chain products and yet retain the active metal sites in a protected 'cage.' Such catalysts were prepared with silica-containing fractal cages. The activity was essentially the same as that of catalysts without the cages. We are currently awaiting follow-up experiments to determine the attrition strength of these catalysts. A second experimental stage was undertaken to prepare and evaluate active FT catalysts formed by atomic-layer deposition [ALD] of active components on supported membranes and particulate supports. The concept was that of depositing active metals (i.e. ruthenium, iron or cobalt) upon membranes with well defined flow channels of small diameter and length such that the catalytic activity and product …
Date: April 15, 2011
Creator: Cronauer, D. C. (Chemical Sciences and Engineering Division)
Object Type: Report
System: The UNT Digital Library
SPOCS User Guide (open access)

SPOCS User Guide

SPOCS implements a graph-based ortholog prediction method to generate a simple tab-delimited table of orthologs, and in addition, html files that provide a visualization of the ortholog/paralog relationships to which gene/protein expression metadata may be overlaid.
Date: April 15, 2013
Creator: Curtis, Darren S.; Phillips, Aaron R. & McCue, Lee Ann
Object Type: Report
System: The UNT Digital Library
Effects of nitrogen additions on above- and belowground carbon dynamics in two tropical forests (open access)

Effects of nitrogen additions on above- and belowground carbon dynamics in two tropical forests

Anthropogenic nitrogen (N) deposition is increasing rapidly in tropical regions, adding N to ecosystems that often have high background N availability. Tropical forests play an important role in the global carbon (C) cycle, yet the effects of N deposition on C cycling in these ecosystems are poorly understood. We used a field N-fertilization experiment in lower and upper elevation tropical rain forests in Puerto Rico to explore the responses of above- and belowground C pools to N addition. As expected, tree stem growth and litterfall productivity did not respond to N fertilization in either of these Nrich forests, indicating a lack of N limitation to net primary productivity (NPP). In contrast, soil C concentrations increased significantly with N fertilization in both forests, leading to larger C stocks in fertilized plots. However, different soil C pools responded to N fertilization differently. Labile (low density) soil C fractions and live fine roots declined with fertilization, while mineral-associated soil C increased in both forests. Decreased soil CO2 fluxes in fertilized plots were correlated with smaller labile soil C pools in the lower elevation forest (R2 = 0.65, p\0.05), and with lower live fine root biomass in the upper elevation forest (R2 = 0.90, …
Date: April 15, 2011
Creator: Cusack, D.; Silver, W. L.; Torn, M. S. & McDowell, W. H.
Object Type: Article
System: The UNT Digital Library
Kenya: Current Conditions and the Challenges Ahead (open access)

Kenya: Current Conditions and the Challenges Ahead

This report discusses the current political conditions of Kenya, which has long been an important ally of the United States. The report focuses particularly on the December 2007 elections, which many international observers have declared as rigged and deeply flawed. The report also discusses violence that erupted once election results were announced, as well as U.S. efforts to urge Kenya toward election reforms.
Date: April 15, 2011
Creator: Dagne, Ted
Object Type: Report
System: The UNT Digital Library
How Legislation Is Brought to the House Floor: A Snapshot of Parliamentary Practice in the 112th Congress (2011-2012) (open access)

How Legislation Is Brought to the House Floor: A Snapshot of Parliamentary Practice in the 112th Congress (2011-2012)

This report provides a statistical snapshot of the forms, origins, and party sponsorship of these measures and of the parliamentary procedures used to bring them to the chamber floor during their initial consideration.
Date: April 15, 2013
Creator: Davis, Christopher M.
Object Type: Report
System: The UNT Digital Library
Federal Grants to State and Local Governments: An Historical Perspective on Contemporary Issues (open access)

Federal Grants to State and Local Governments: An Historical Perspective on Contemporary Issues

This report provides a historical synopsis of the evolving nature of the federal grants-in-aid system, focusing on the role Congress has played in defining the system's scope and nature. It begins with an overview of the contemporary federal grants-in-aid system and then examines its evolution over time, focusing on the internal and external factors that have influenced congressional decisions concerning the system's development. It concludes with an assessment of the scope and nature of the contemporary federal grants-in-aid system and raises several issues for congressional consideration, including possible ways to augment congressional capacity to provide effective oversight of this system.
Date: April 15, 2014
Creator: Dilger, Robert Jay
Object Type: Report
System: The UNT Digital Library