Resource Type

The RHIC polarized source upgrade (open access)

The RHIC polarized source upgrade

N/A
Date: October 15, 2013
Creator: A., Zelenski; Atoian, G.; Ritter, J.; Steski, D.; Davydenko, V.; Ivanov, A. et al.
System: The UNT Digital Library
Lifecycle Assessment of Beijing-Area Building Energy Use and Emissions: Summary Findings and Policy Applications (open access)

Lifecycle Assessment of Beijing-Area Building Energy Use and Emissions: Summary Findings and Policy Applications

Buildings are at the locus of three trends driving China's increased energy use and emissions: urbanization, growing personal consumption, and surging heavy industrial production. Migration to cities and urban growth create demand for new building construction. Higher levels of per-capita income and consumption drive building operational energy use with demand for higher intensity lighting, thermal comfort, and plug-load power. Demand for new buildings, infrastructure, and electricity requires heavy industrial production. In order to quantify the implications of China's ongoing urbanization, rising personal consumption, and booming heavy industrial sector, this study presents a lifecycle assessment (LCA) of the energy use and carbon emissions related to residential and commercial buildings. The purpose of the LCA model is to quantify the impact of a given building and identify policy linkages to mitigate energy demand and emissions growth related to China's new building construction. As efficiency has become a higher priority with growing energy demand, policy and academic attention to buildings has focused primarily on operational energy use. Existing studies estimate that building operational energy consumption accounts for approximately 25% of total primary energy use in China. However, buildings also require energy for mining, extracting, processing, manufacturing, and transporting materials, as well as energy …
Date: September 15, 2010
Creator: Aden, Nathaniel; Qin, Yining & Fridley, David
System: The UNT Digital Library
Urban Form Energy Use and Emissions in China: Preliminary Findings and Model Proof of Concept (open access)

Urban Form Energy Use and Emissions in China: Preliminary Findings and Model Proof of Concept

Urbanization is reshaping China's economy, society, and energy system. Between 1990 and 2008 China added more than 300 million new urban residents, bringing the total urbanization rate to 46%. The ongoing population shift is spurring energy demand for new construction, as well as additional residential use with the replacement of rural biomass by urban commercial energy services. This project developed a modeling tool to quantify the full energy consequences of a particular form of urban residential development in order to identify energy- and carbon-efficient modes of neighborhood-level development and help mitigate resource and environmental implications of swelling cities. LBNL developed an integrated modeling tool that combines process-based lifecycle assessment with agent-based building operational energy use, personal transport, and consumption modeling. The lifecycle assessment approach was used to quantify energy and carbon emissions embodied in building materials production, construction, maintenance, and demolition. To provide more comprehensive analysis, LBNL developed an agent-based model as described below. The model was applied to LuJing, a residential development in Jinan, Shandong Province, to provide a case study and model proof of concept. This study produced results data that are unique by virtue of their scale, scope and type. Whereas most existing literature focuses on building-, …
Date: December 15, 2010
Creator: Aden, Nathaniel; Qin, Yining & Fridley, David
System: The UNT Digital Library
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.
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.
System: The UNT Digital Library
Ex-Im Bank: No Quorum, No Problem? (open access)

Ex-Im Bank: No Quorum, No Problem?

This report discusses the operation on a limited basis of the Export-Import Bank (Ex-Im Bank) despite a renewal of its general statutory charter through FY2019 (P.L. 114-94,
Date: September 15, 2016
Creator: Akhtar, Shayerah Ilias
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
System: The UNT Digital Library
Nanosensors as Reservoir Engineering Tools to Map Insitu Temperature Distributions in Geothermal Reservoirs (open access)

Nanosensors as Reservoir Engineering Tools to Map Insitu Temperature Distributions in Geothermal Reservoirs

The feasibility of using nanosensors to measure temperature distribution and predict thermal breakthrough in geothermal reservoirs is addressed in this report. Four candidate sensors were identified: melting tin-bismuth alloy nanoparticles, silica nanoparticles with covalently-attached dye, hollow silica nanoparticles with encapsulated dye and impermeable melting shells, and dye-polymer composite time-temperature indicators. Four main challenges associated with the successful implementation of temperature nanosensors were identified: nanoparticle mobility in porous and fractured media, the collection and detection of nanoparticles at the production well, engineering temperature sensing mechanisms that are both detectable and irreversible, and inferring the spatial geolocation of temperature measurements in order to map temperature distribution. Initial experiments were carried out to investigate each of these challenges. It was demonstrated in a slim-tube injection experiment that it is possible to transport silica nanoparticles over large distances through porous media. The feasibility of magnetic collection of nanoparticles from produced fluid was evaluated experimentally, and it was estimated that 3% of the injected nanoparticles were recovered in a prototype magnetic collection device. An analysis technique was tailored to nanosensors with a dye-release mechanism to estimate temperature measurement geolocation by analyzing the return curve of the released dye. This technique was used in a hypothetical …
Date: June 15, 2011
Creator: Ames, Morgan.
System: The UNT Digital Library
Preliminary Screening Analysis for the Environmental Risk Evaluation System: Task 2.1.1: Evaluating Effects of Stressors – Fiscal Year 2010 Progress Report: Environmental Effects of Marine and Hydrokinetic Energy (open access)

Preliminary Screening Analysis for the Environmental Risk Evaluation System: Task 2.1.1: Evaluating Effects of Stressors – Fiscal Year 2010 Progress Report: Environmental Effects of Marine and Hydrokinetic Energy

Possible environmental effects of marine and hydrokinetic (MHK) energy development are not well understood, and yet regulatory agencies are required to make decisions in spite of substantial uncertainty about environmental impacts and their long-term effects. An understanding of risk associated with likely interactions between MHK installations and aquatic receptors, including animals, habitats, and ecosystems, can help reduce the level of uncertainty and focus regulatory actions and scientific studies on interactions of most concern. As a first step in developing the Pacific Northwest National Laboratory (PNNL) Environmental Risk Evaluation System (ERES), PNNL scientists conducted a preliminary risk screening analysis on three initial MHK cases - a tidal project in Puget Sound using Open Hydro turbines, a wave project off the coast of Oregon using Ocean Power Technologies point attenuator buoys, and a riverine current project in the Mississippi River using Free Flow turbines. Through an iterative process, the screening analysis revealed that top-tier stressors in all three cases were the effects of the dynamic physical presence of the device (e.g., strike), accidents, and effects of the static physical presence of the device (e.g., habitat alteration). Receptor interactions with these stressors at the four highest tiers of risk were dominated by marine …
Date: November 15, 2010
Creator: Anderson, Richard M.; Copping, Andrea E. & Van Cleve, Frances B.
System: The UNT Digital Library
Federal Agency Authority to Contract for Electric Power and Renewable Energy Supply (open access)

Federal Agency Authority to Contract for Electric Power and Renewable Energy Supply

None
Date: August 15, 2011
Creator: Andrews, Anthony
System: The UNT Digital Library
Dynamic Behavior of Sand: Annual Report FY 11 (open access)

Dynamic Behavior of Sand: Annual Report FY 11

Currently, design of earth-penetrating munitions relies heavily on empirical relationships to estimate behavior, making it difficult to design novel munitions or address novel target situations without expensive and time-consuming full-scale testing with relevant system and target characteristics. Enhancing design through numerical studies and modeling could help reduce the extent and duration of full-scale testing if the models have enough fidelity to capture all of the relevant parameters. This can be separated into three distinct problems: that of the penetrator structural and component response, that of the target response, and that of the coupling between the two. This project focuses on enhancing understanding of the target response, specifically granular geomaterials, where the temporal and spatial multi-scale nature of the material controls its response. As part of the overarching goal of developing computational capabilities to predict the performance of conventional earth-penetrating weapons, this project focuses specifically on developing new models and numerical capabilities for modeling sand response in ALE3D. There is general recognition that granular materials behave in a manner that defies conventional continuum approaches which rely on response locality and which degrade in the presence of strong response nonlinearities, localization, and phase gradients. There are many numerical tools available to address …
Date: March 15, 2012
Creator: Antoun, Tarabay; Herbold, Eric & Johnson, Scott
System: The UNT Digital Library
Energy Saving Melting and Revert Reduction Technology: Innovative Semi-Solid Metal (SSM) Processing (open access)

Energy Saving Melting and Revert Reduction Technology: Innovative Semi-Solid Metal (SSM) Processing

Semi-solid metal (SSM) processing has emerged as an attractive method for near-net-shape manufacturing due to the distinct advantages it holds over conventional near-net-shape forming technologies. These advantages include lower cycle time, increased die life, reduced porosity, reduced solidification shrinkage, improved mechanical properties, etc. SSM processing techniques can not only produce the complex dimensional details (e.g. thin-walled sections) associated with conventional high-pressure die castings, but also can produce high integrity castings currently attainable only with squeeze and low-pressure permanent mold casting processes. There are two primary semi-solid processing routes, (a) thixocasting and (b) rheocasting. In the thixocasting route, one starts from a non-dendritic solid precursor material that is specially prepared by a primary aluminum manufacturer, using continuous casting methods. Upon reheating this material into the mushy (a.k.a. "two-phase") zone, a thixotropic slurry is formed, which becomes the feed for the casting operation. In the rheocasting route (a.k.a. "slurry-on-demand" or "SoD"), one starts from the liquid state, and the thixotropic slurry is formed directly from the melt via careful thermal management of the system; the slurry is subsequently fed into the die cavity. Of these two routes, rheocasting is favored in that there is no premium added to the billet cost, and …
Date: August 15, 2012
Creator: Apelian, Diran
System: The UNT Digital Library
Tethered Lubricants (open access)

Tethered Lubricants

We have performed extensive experimental and theoretical studies of interfacial friction, relaxation dynamics, and thermodynamics of polymer chains tethered to points, planes, and particles. A key result from our tribology studies using lateral force microscopy (LFM) measurements of polydisperse brushes of linear and branched chains densely grafted to planar substrates is that there are exceedingly low friction coefficients for these systems. Specific project achievements include: (1) Synthesis of three-tiered lubricant films containing controlled amounts of free and pendent PDMS chains, and investigated the effect of their molecular weight and volume fraction on interfacial friction. (2.) Detailed studies of a family of hairy particles termed nanoscale organic hybrid materials (NOHMs) and demonstration of their use as lubricants.
Date: September 15, 2010
Creator: Archer, Lynden
System: The UNT Digital Library
The European Union: Current Challenges and Future Prospects (open access)

The European Union: Current Challenges and Future Prospects

This report provides a brief history of the European Union (EU) and the major challenges currently confronting the EU as an institution. It also discusses the potential implications both for the EU itself and for U.S.-EU relations.
Date: February 15, 2016
Creator: Archick, Kristin
System: The UNT Digital Library
The European Union: Questions and Answers (open access)

The European Union: Questions and Answers

This report provides a brief overview of the European Union (EU), an economic and political partnership between 27 sovereign member states. The report describes the formation of the EU, the three main institutions of the EU, and the EU's relationship with the United States.
Date: January 15, 2014
Creator: Archick, Kristin
System: The UNT Digital Library
European Security, Islamist Terrorism, and Returning Fighters (open access)

European Security, Islamist Terrorism, and Returning Fighters

This report discusses European concerns about Islamist terrorism, which have been heightened considerably by several attacks over the last year and the growing number of European citizens training and fighting with extremist groups in foreign conflicts (especially in Syria and Iraq).
Date: September 15, 2015
Creator: Archick, Kristin & Belkin, Paul
System: The UNT Digital Library
Western Sahara (open access)

Western Sahara

This report discusses how Morocco and the independence-seeking Popular Front for the Liberation of Saqiat al Hamra and Rio de Oro (Polisario) have been vying for control of the Western Sahara, a former Spanish territory, since the 1970s. The report discusses recent settlement attempts, as well as how the Western Sahara issue has affected Algerian-Moroccan bilaterial relations, Moroccan relations with the African Union, and regional cooperation on economic and security issues. The report also discusses the United States' involvement in and stance on the issue.
Date: February 15, 2011
Creator: Arieff, Alexis
System: The UNT Digital Library
Evaluating greenhouse gas emissions from hydropower complexes on large rivers in Eastern Washington (open access)

Evaluating greenhouse gas emissions from hydropower complexes on large rivers in Eastern Washington

Water bodies, such as freshwater lakes, are known to be net emitters of carbon dioxide (CO2), and methane (CH4). In recent years, significant greenhouse gas (GHG) emissions from tropical, boreal, and mid-latitude reservoirs have been reported. At a time when hydropower is increasing worldwide, better understanding of seasonal and regional variation in GHG emissions is needed in order to develop a predictive understanding of such fluxes within man-made impoundments. We examined power-producing dam complexes within xeric temperate locations in the northwestern United States. Sampling environments on the Snake (Lower Monumental Dam Complex) and Columbia Rivers (Priest Rapids Dam Complex) included tributary, mainstem, embayment, forebay, and tailrace areas during winter and summer 2012. At each sampling location, GHG measurement pathways included surface gas flux, degassing as water passed through dams during power generation, ebullition within littoral embayments, and direct sampling of hyporheic pore-water. Measurements were also carried out in a free-flowing reach of the Columbia River to estimate unaltered conditions. Surface flux resulted in very low emissions, with reservoirs acting as a sink for CO2 (up to –262 mg m-2 d-1, which is within the range previously reported for similarly located reservoirs). Surface flux of methane remained below 1 mg CH4 …
Date: March 15, 2013
Creator: Arntzen, Evan V.; Miller, Benjamin L.; O'Toole, Amanda C.; Niehus, Sara E. & Richmond, Marshall C.
System: The UNT Digital Library
U.S. Department of Energy Clean Cities Five-Year Strategic Plan (open access)

U.S. Department of Energy Clean Cities Five-Year Strategic Plan

Clean Cities is a government-industry partnership sponsored by the U.S. Department of Energy's (DOE) Vehicle Technologies Program, which is part of the Office of Energy Efficiency and Renewable Energy. Working with its network of about 100 local coalitions and more than 6,500 stakeholders across the country, Clean Cities delivers on its mission to reduce petroleum consumption in on-road transportation. In its work to reduce petroleum use, Clean Cities focuses on a portfolio of technologies that includes electric drive, propane, natural gas, renewable natural gas/biomethane, ethanol/E85, biodiesel/B20 and higher-level blends, fuel economy, and idle reduction. Over the past 17 years, Clean Cities coalitions have displaced more than 2.4 billion gallons of petroleum; they are on track to displace 2.5 billion gallons of gasoline per year by 2020. This Clean Cities Strategic Plan lays out an aggressive five-year agenda to help DOE Clean Cities and its network of coalitions and stakeholders accelerate the deployment of alternative fuel and advanced technology vehicles, while also expanding the supporting infrastructure to reduce petroleum use. Today, Clean Cities has a far larger opportunity to make an impact than at any time in its history because of its unprecedented $300 million allocation for community-based deployment projects from …
Date: February 15, 2011
Creator: Associates, Cambridge Concord
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
System: The UNT Digital Library
Mandatory Spending Since 1962 (open access)

Mandatory Spending Since 1962

Mandatory spending includes federal government spending on entitlement programs as well as other budget outlays controlled by laws other than appropriation acts. Entitlement programs such as Social Security and Medicare make up the bulk of mandatory spending. This report looks at mandatory spending and how it has grown over time relative to total federal spending and the size of the U.S. economy. It also analyzes future mandatory spending levels and how they are projected to impact the federal budget.
Date: September 15, 2010
Creator: Austin, D. A. & Levit, Mindy R.
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
System: The UNT Digital Library
The Debt Limit: History and Recent Increases (open access)

The Debt Limit: History and Recent Increases

This report discusses how the total debt of the federal government can increase, an historical overview of debt limits, and how the current economic slowdown has led to higher deficits and thereby a series of debt limit increases, as well as legislation related to these increases.
Date: October 15, 2013
Creator: Austin, D. Andrew & Levit, Mindy R.
System: The UNT Digital Library
Exascale for Energy: The Role of Exascale Computing in Energy Security (open access)

Exascale for Energy: The Role of Exascale Computing in Energy Security

How will the United States satisfy energy demand in a tightening global energy marketplace while, at the same time, reducing greenhouse gas emissions? Exascale computing -- expected to be available within the next eight to ten years ? may play a crucial role in answering that question by enabling a paradigm shift from test-based to science-based design and engineering. Computational modeling of complete power generation systems and engines, based on scientific first principles, will accelerate the improvement of existing energy technologies and the development of new transformational technologies by pre-selecting the designs most likely to be successful for experimental validation, rather than relying on trial and error. The predictive understanding of complex engineered systems made possible by computational modeling will also reduce the construction and operations costs, optimize performance, and improve safety. Exascale computing will make possible fundamentally new approaches to quantifying the uncertainty of safety and performance engineering. This report discusses potential contributions of exa-scale modeling in four areas of energy production and distribution: nuclear power, combustion, the electrical grid, and renewable sources of energy, which include hydrogen fuel, bioenergy conversion, photovoltaic solar energy, and wind turbines. Examples of current research are taken from projects funded by the U.S. …
Date: July 15, 2010
Creator: Authors, Various
System: The UNT Digital Library