Neutron Damage in Mechanically-Cooled High-Purity Germanium Detectors for Field-Portable Prompt Gamma Neutron Activation Analysis (PGNAA) Systems (open access)

Neutron Damage in Mechanically-Cooled High-Purity Germanium Detectors for Field-Portable Prompt Gamma Neutron Activation Analysis (PGNAA) Systems

Prompt Gamma Neutron Activation (PGNAA) systems require the use of a gamma-ray spectrometer to record the gamma-ray spectrum of an object under test and allow the determination of the object’s composition. Field-portable systems, such as Idaho National Laboratory’s PINS system, have used standard liquid-nitrogen-cooled high-purity germanium (HPGe) detectors to perform this function. These detectors have performed very well in the past, but the requirement of liquid-nitrogen cooling limits their use to areas where liquid nitrogen is readily available or produced on-site. Also, having a relatively large volume of liquid nitrogen close to the detector can impact some assessments, possibly leading to a false detection of explosives or other nitrogen-containing chemical. Use of a mechanically-cooled HPGe detector is therefore very attractive for PGNAA applications where nitrogen detection is critical or where liquid-nitrogen logistics are problematic. Mechanically-cooled HPGe detectors constructed from p-type germanium, such as Ortec’s trans-SPEC, have been commercially available for several years. In order to assess whether these detectors would be suitable for use in a fielded PGNAA system, Idaho National Laboratory (INL) has been performing a number of tests of the resistance of mechanically-cooled HPGe detectors to neutron damage. These detectors have been standard commercially-available p-type HPGe detectors as …
Date: October 1, 2013
Creator: Seabury, E. H.; Wharton, C. J.; Caffrey, A. J.; McCabe, J. B. & Van Siclen, C. Dew.
Object Type: Article
System: The UNT Digital Library
The oxidation of aluminum at high temperature studied by Thermogravimetric Analysis and Differential Scanning Calorimetry. (open access)

The oxidation of aluminum at high temperature studied by Thermogravimetric Analysis and Differential Scanning Calorimetry.

The oxidation in air of high-purity Al foil was studied as a function of temperature using Thermogravimetric Analysis with Differential Scanning Calorimetry (TGA/DSC). The rate and/or extent of oxidation was found to be a non-linear function of the temperature. Between 650 and 750 %C2%B0C very little oxidation took place; at 850 %C2%B0C oxidation occurred after an induction period, while at 950 %C2%B0C oxidation occurred without an induction period. At oxidation temperatures between 1050 and 1150 %C2%B0C rapid passivation of the surface of the aluminum foil occurred, while at 1250 %C2%B0C and above, an initial rapid mass increase was observed, followed by a more gradual increase in mass. The initial rapid increase was accompanied by a significant exotherm. Cross-sections of oxidized specimens were characterized by scanning electron microscopy (SEM); the observed alumina skin thicknesses correlated qualitatively with the observed mass increases.
Date: October 1, 2013
Creator: Coker, Eric Nicholas
Object Type: Report
System: The UNT Digital Library
Executive Summary - Natural Gas and the Transformation of the U.S. Energy Sector: Electricity (open access)

Executive Summary - Natural Gas and the Transformation of the U.S. Energy Sector: Electricity

In November 2012, the Joint Institute for Strategic Energy Analysis (JISEA) released a new report, 'Natural Gas and the Transformation of the U.S. Energy Sector: Electricity.' The study provides a new methodological approach to estimate natural gas related greenhouse gas (GHG) emissions, tracks trends in regulatory and voluntary industry practices, and explores various electricity futures. The Executive Summary provides key findings, insights, data, and figures from this major study.
Date: January 1, 2013
Creator: Logan, J.; Heath, G.; Macknick, J.; Paranhos, E.; Boyd, W. & Carlson, K.
Object Type: Report
System: The UNT Digital Library
NREL Invention Speeds Solar Cell Quality Testing for Industry (Fact Sheet) (open access)

NREL Invention Speeds Solar Cell Quality Testing for Industry (Fact Sheet)

A solid-state optical system, invented by the National Renewable Energy Laboratory (NREL), measures solar cell quantum efficiency (QE) in less than a second, enabling a suite of new capabilities for solar cell manufacturers. QE is a measurement of how cells respond to light across the solar spectrum, but traditional methods for measuring QE had been too slow, limiting its application to small samples pulled from the production line and analyzed in laboratories. NREL's technique, commercialized by Tau Science as the FlashQE(TM) system, uses a solid-state light source, synchronized electronics, and advanced mathematical analysis to parallel-process QE data in a tiny fraction of the time required by the current method, allowing its use on every solar cell passing through a production line.
Date: August 1, 2013
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Energy Retrofit Field Study and Best Practices in a Hot-Humid Climate (open access)

Energy Retrofit Field Study and Best Practices in a Hot-Humid Climate

Energy efficiency improvement as a component of comprehensive renovation was investigated under U.S. Department of Energy (DOE) funding of the Building America Partnership for Improved Residential Construction (BA-PIRC). Researchers at the Florida Solar Energy Center (FSEC) worked with affordable housing partners renovating foreclosed homes built from the 1950's through the 2000's in the hot-humid climate (within the Southern census region), primarily in Florida. Researchers targeted a 30% improvement in whole-house energy efficiency along with the health and safety, durability, and comfort guidelines outlined in DOE's Builders Challenge Program (Version 1) Quality Criteria.
Date: March 1, 2013
Creator: McIvaine, J.; Sutherland, K. & Martin, E.
Object Type: Report
System: The UNT Digital Library
Efficient Multifamily Homes in a Hot-Humid Climate by Atlantic Housing Partners (open access)

Efficient Multifamily Homes in a Hot-Humid Climate by Atlantic Housing Partners

With assistance from the Florida Solar Energy Center (FSEC) and its Building America Partnership for Improved Residential Construction (BA-PIRC), Atlantic Housing Partners (AHP) has implemented a high performance, systems engineered package of measures. This report demonstrates how the initiative achieves Building America (BA) goals of 30%-50% energy savings. Specifically, the goals are documented as being achieved in the new construction multifamily housing sector in the hot humid climate. Results from energy modeling of the high performance package are presented. The role of utility allowance calculations, used as part of the low-income housing tax credit process, to value those energy savings is discussed, as is customer satisfaction with heat pump water heaters.
Date: April 1, 2013
Creator: Chasar, D. & Martin, E.
Object Type: Report
System: The UNT Digital Library
A Python Object Oriented & Data Driven Testing Infrastructure for an Environmental Information Management System (open access)

A Python Object Oriented & Data Driven Testing Infrastructure for an Environmental Information Management System

None
Date: May 1, 2013
Creator: Barbosa, E & Laguna, G W
Object Type: Report
System: The UNT Digital Library
Feasibility Study of Economics and Performance of Solar Photovoltaics at the Brisbane Baylands Brownfield Site in Brisbane, California. (open access)

Feasibility Study of Economics and Performance of Solar Photovoltaics at the Brisbane Baylands Brownfield Site in Brisbane, California.

The U.S. Environmental Protection Agency (EPA), in accordance with the RE-Powering America's Land initiative, selected the Brisbane Baylands site in Brisbane, California, for a feasibility study of renewable energy production. The National Renewable Energy Laboratory (NREL) provided technical assistance for this project. The purpose of this report is to assess the site for a possible photovoltaic (PV) system installation and estimate the cost, performance, and site impacts of different PV options. In addition, the report recommends financing options that could assist in the implementation of a PV system at the site.
Date: April 1, 2013
Creator: Salasovich, J.; Geiger, J.; Healey, V. & Mosey, G.
Object Type: Report
System: The UNT Digital Library
Bay Ridge Gardens - Mixed-Humid Affordable Multifamily Housing Deep Energy Retrofit (open access)

Bay Ridge Gardens - Mixed-Humid Affordable Multifamily Housing Deep Energy Retrofit

Under this project, Newport Partners (as part of the BA-PIRC research team) evaluated the installation, measured performance, and cost-effectiveness of efficiency upgrade measures for a tenant-in-place DER at the Bay Ridge multifamily (MF) development in Annapolis, Maryland. The design and construction phase of the Bay Ridge project was completed in August 2012. This report summarizes system commissioning, short-term test results, utility bill data analysis, and analysis of real-time data collected over a one-year period after the retrofit was complete. The Bay Ridge project is comprised of a 'base scope' retrofit which was estimated to achieve a 30%+ savings (relative to pre-retrofit) on 186 apartments, and a 'DER scope' which was estimated to achieve 50% savings (relative to pre-retrofit) on a 12-unit building. The base scope was applied to the entire apartment complex, except for one 12-unit building which underwent the DER scope. A wide range of efficiency measures was applied to pursue this savings target for the DER building, including improvements/replacements of mechanical equipment and distribution systems, appliances, lighting and lighting controls, the building envelope, hot water conservation measures, and resident education. The results of this research build upon the current body of knowledge of multifamily retrofits. Towards this end, …
Date: August 1, 2013
Creator: Lyons, J.; Moore, M. & Thompson, M.
Object Type: Report
System: The UNT Digital Library
GPU-optimized Code for Long-term Simulations of Beam-beam Effects in Colliders (open access)

GPU-optimized Code for Long-term Simulations of Beam-beam Effects in Colliders

We report on the development of the new code for long-term simulation of beam-beam effects in particle colliders. The underlying physical model relies on a matrix-based arbitrary-order symplectic particle tracking for beam transport and the Bassetti-Erskine approximation for beam-beam interaction. The computations are accelerated through a parallel implementation on a hybrid GPU/CPU platform. With the new code, a previously computationally prohibitive long-term simulations become tractable. We use the new code to model the proposed medium-energy electron-ion collider (MEIC) at Jefferson Lab.
Date: June 1, 2013
Creator: Roblin, Yves; Morozov, Vasiliy; Terzic, Balsa; Aturban, Mohamed A.; Ranjan, D. & Zubair, Mohammed
Object Type: Article
System: The UNT Digital Library
Retail Buildings: Assessing and Reducing Plug and Process Loads in Retail Buildings (Fact Sheet) (open access)

Retail Buildings: Assessing and Reducing Plug and Process Loads in Retail Buildings (Fact Sheet)

Plug and process loads (PPLs) in commercial buildings account for almost 5% of U.S. primary energy consumption. Minimizing these loads is a primary challenge in the design and operation of an energy-efficient building. PPLs are not related to general lighting, heating, ventilation, cooling, and water heating, and typically do not provide comfort to the occupants. They use an increasingly large fraction of the building energy use pie because the number and variety of electrical devices have increased along with building system efficiency. Reducing PPLs is difficult because energy efficiency opportunities and the equipment needed to address PPL energy use in retail spaces are poorly understood.
Date: April 1, 2013
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Tritium Formation and Mitigation in High-Temperature Reactor Systems (open access)

Tritium Formation and Mitigation in High-Temperature Reactor Systems

Tritium is a radiologically active isotope of hydrogen. It is formed in nuclear reactors by neutron absorption and ternary fission events and can subsequently escape into the environment. To prevent the tritium contamination of proposed reactor buildings and surrounding sites, this study examines the root causes and potential mitigation strategies for permeation of tritium (such as: materials selection, inert gas sparging, etc...). A model is presented that can be used to predict permeation rates of hydrogen through metallic alloys at temperatures from 450–750 degrees C. Results of the diffusion model are presented for a steady production of tritium
Date: March 1, 2013
Creator: Sabharwall, Piyush; Stoots, Carl & Schmutz, Hans A.
Object Type: Report
System: The UNT Digital Library
Preliminary photovoltaic arc-fault prognostic tests using sacrificial fiber optic cabling. (open access)

Preliminary photovoltaic arc-fault prognostic tests using sacrificial fiber optic cabling.

Through the New Mexico Small Business Assistance Program, Sandia National Laboratories worked with Sentient Business Systems, Inc. to develop and test a novel photovoltaic (PV) arc-fault detection system. The system operates by pairing translucent polymeric fiber optic sensors with electrical circuitry so that any external abrasion to the system or internal heating causes the fiber optic connection to fail or detectably degrade. A periodic pulse of light is sent through the optical path using a transmitter-receiver pair. If the receiver does not detect the pulse, an alarm is sounded and the PV system can be de-energized. This technology has the unique ability to prognostically determine impending failures to the electrical system in two ways: (a) the optical connection is severed prior to physical abrasion or cutting of PV DC electrical conductors, and (b) the polymeric fiber optic cable melts via Joule heating before an arc-fault is established through corrosion. Three arc-faults were created in different configurations found in PV systems with the integrated fiber optic system to determine the feasibility of the technology. In each case, the fiber optic cable was broken and the system annunciated the fault.
Date: February 1, 2013
Creator: Johnson, Jay; Blemel, Kenneth D. & Peter, Francis
Object Type: Report
System: The UNT Digital Library
Fresh-Core Reload of the Neutron Radiography (NRAD) Reactor with Uranium(20)-Erbium-Zirconium-Hydride Fuel (open access)

Fresh-Core Reload of the Neutron Radiography (NRAD) Reactor with Uranium(20)-Erbium-Zirconium-Hydride Fuel

The neutron radiography (NRAD) reactor is a 250 kW TRIGA® (Training, Research, Isotopes, General Atomics) Mark II , tank-type research reactor currently located in the basement, below the main hot cell, of the Hot Fuel Examination Facility (HFEF) at the Idaho National Laboratory (INL). It is equipped with two beam tubes with separate radiography stations for the performance of neutron radiography irradiation on small test components. The initial critical configuration developed during the fuel loading process, which contains only 56 fuel elements, has been evaluated as an acceptable benchmark experiment. The 60-fuel-element operational core configuration of the NRAD LEU TRIGA reactor has also been evaluated as an acceptable benchmark experiment. Calculated eigenvalues differ significantly (~±1%) from the benchmark eigenvalue and have demonstrated sensitivity to the thermal scattering treatment of hydrogen in the U-Er-Zr-H fuel.
Date: March 1, 2013
Creator: Bess, John D.; Maddock, Thomas L.; Marshall, Margaret A. & Montierth, Leland M.
Object Type: Report
System: The UNT Digital Library
Lab Tests Demonstrate Effectiveness of Advanced Power Strips (Fact Sheet) (open access)

Lab Tests Demonstrate Effectiveness of Advanced Power Strips (Fact Sheet)

NREL engineers evaluate the functionalities of advanced power strips and help consumers choose the right one for their plug loads.
Date: September 1, 2013
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Vehicle Technologies' Fact of the Week 2012 (open access)

Vehicle Technologies' Fact of the Week 2012

Each week the U.S. Department of Energy s Vehicle Technology Office (VTO) posts a Fact of the Week on their website: http://www1.eere.energy.gov/vehiclesandfuels/ . These Facts provide statistical information, usually in the form of charts and tables, on vehicle sales, fuel economy, gasoline prices, and other transportation-related trends. Each Fact is a stand-alone page that includes a graph, text explaining the significance of the data, the supporting information on which the graph was based, and the source of the data. A link to the current week s Fact is available on the VTO homepage, but older Facts are archived and still available at: http://www1.eere.energy.gov/vehiclesandfuels/facts/. This report is a compilation of the Facts that were posted during calendar year 2012. The Facts were written and prepared by staff in Oak Ridge National Laboratory's Center for Transportation Analysis.
Date: February 1, 2013
Creator: Davis, Stacy Cagle; Diegel, Susan W; Moore, Sheila A & Boundy, Robert Gary
Object Type: Report
System: The UNT Digital Library
Mobile biometric device (MBD) technology : summary of selected first responder experiences in pilot projects. (open access)

Mobile biometric device (MBD) technology : summary of selected first responder experiences in pilot projects.

Mobile biometric devices (MBDs) capable of both enrolling individuals in databases and performing identification checks of subjects in the field are seen as an important capability for military, law enforcement, and homeland security operations. The technology is advancing rapidly. The Department of Homeland Security Science and Technology Directorate through an Interagency Agreement with Sandia sponsored a series of pilot projects to obtain information for the first responder law enforcement community on further identification of requirements for mobile biometric device technology. Working with 62 different jurisdictions, including components of the Department of Homeland Security, Sandia delivered a series of reports on user operation of state-of-the-art mobile biometric devices. These reports included feedback information on MBD usage in both operational and exercise scenarios. The findings and conclusions of the project address both the limitations and possibilities of MBD technology to improve operations. Evidence of these possibilities can be found in the adoption of this technology by many agencies today and the cooperation of several law enforcement agencies in both participating in the pilot efforts and sharing of information about their own experiences in efforts undertaken separately.
Date: June 1, 2013
Creator: Aldridge, Chris D.
Object Type: Report
System: The UNT Digital Library
Analysis of Pu-Only Partitioning Strategies in LMFBR Fuel Cycles (open access)

Analysis of Pu-Only Partitioning Strategies in LMFBR Fuel Cycles

Sodium cooled Fast Reactors (SFR) have been under consideration for production of electricity, fissile material production, and for destruction of transuranics for decades. The neutron economy of a SFR can be operated in one of two ways. One possibility is to operate the reactor in a transuranic burner mode which has been the focus of active R&D in the last 15 years. However, prior to that the focus was on breeding transuranics. This later mode of managing the neutron economy relies on ensuring the maximum fuel utilization possible in such a way as to maximize the amount of plutonium produced per unit of fission energy in the reactor core. The goal of maximizing plutonium production in this study is as fissile feed stock for the production of MOX fuel to be used in Light Water Reactors (LWR). Throughout the l970’s, this fuel cycle scenario was the focus of much research by the Atomic Energy Commission in the event that uranium supplies would be scarce. To date, there has been sufficient uranium to supply the once through nuclear fuel cycle. However, interest in a synergistic relationship Liquid Metal Fast Breeder Reactors (LMFBR) and a consumer LWR fleet persists, prompting this study. …
Date: February 1, 2013
Creator: Bays, Samuel & Youinou, Gilles
Object Type: Report
System: The UNT Digital Library

Models for Battery Reliability and Lifetime: Applications in Design and Health Management

This presentation discusses models for battery reliability and lifetime and the Battery Ownership Model.
Date: June 1, 2013
Creator: Smith, K.; Neubauer, J.; Wood, E.; Jun, M. & Pesaran, A.
Object Type: Presentation
System: The UNT Digital Library

Performance and Reliability of Interface Materials for Automotive Power Electronics

Thermal management and reliability are important because excessive temperature can degrade the performance, life, and reliability of power electronics and electric motors. Advanced thermal management technologies enable keeping temperature within limits; higher power densities; and lower cost materials, configurations and systems. Thermal interface materials, bonded interface materials and the reliability of bonded interfaces are discussed in this presentation.
Date: July 1, 2013
Creator: Narumanchi, S.; DeVoto, D.; Mihalic, M. & Paret, P.
Object Type: Presentation
System: The UNT Digital Library
Development of Ultra High Gradient and High Q{sub 0} Superconducting Radio Frequency Cavities (open access)

Development of Ultra High Gradient and High Q{sub 0} Superconducting Radio Frequency Cavities

We report on the recent progress at Jefferson Lab in developing ultra high gradient and high Q{sub 0} superconducting radio frequency (SRF) cavities for future SRF based machines. A new 1300 MHz 9-cell prototype cavity is being fabricated. This cavity has an optimized shape in terms of the ratio of the peak surface field (both magnetic and electric) to the acceleration gradient, hence the name low surface field (LSF) shape. The goal of the effort is to demonstrate an acceleration gradient of 50 MV/m with Q{sub 0} of 10{sup 10} at 2 K in a 9-cell SRF cavity. Fine-grain niobium material is used. Conventional forming, machining and electron beam welding method are used for cavity fabrication. New techniques are adopted to ensure repeatable, accurate and inexpensive fabrication of components and the full assembly. The completed cavity is to be first mechanically polished to a mirror-finish, a newly acquired in-house capability at JLab, followed by the proven ILC-style processing recipe established already at JLab. In parallel, new single-cell cavities made from large-grain niobium material are made to further advance the cavity treatment and processing procedures, aiming for the demonstration of an acceleration gradient of 50 MV/m with Q{sub 0} of 2�10{sup …
Date: June 1, 2013
Creator: Geng, Rongli; Clemens, William A.; Follkie, James E.; Harris, Teena M.; Kushnick, Peter W.; Machie, Danny et al.
Object Type: Article
System: The UNT Digital Library
Land-Use Requirements for Solar Power Plants in the United States (open access)

Land-Use Requirements for Solar Power Plants in the United States

This report provides data and analysis of the land use associated with utility-scale ground-mounted solar facilities, defined as installations greater than 1 MW. We begin by discussing standard land-use metrics as established in the life-cycle assessment literature and then discuss their applicability to solar power plants. We present total and direct land-use results for various solar technologies and system configurations, on both a capacity and an electricity-generation basis. The total area corresponds to all land enclosed by the site boundary. The direct area comprises land directly occupied by solar arrays, access roads, substations, service buildings, and other infrastructure. As of the third quarter of 2012, the solar projects we analyze represent 72% of installed and under-construction utility-scale PV and CSP capacity in the United States.
Date: June 1, 2013
Creator: Ong, S.; Campbell, C.; Denholm, P.; Margolis, R. & Heath, G.
Object Type: Report
System: The UNT Digital Library
Reducing Office Plug Loads through Simple and Inexpensive Advanced Power Strips: Preprint (open access)

Reducing Office Plug Loads through Simple and Inexpensive Advanced Power Strips: Preprint

This paper documents the process (and results) of applying Advanced Power Strips with various control approaches.
Date: July 1, 2013
Creator: Metzger, I.; Sheppy, M. & Cutler, D.
Object Type: Article
System: The UNT Digital Library
EGS rock reactions with Supercritical CO2 saturated with water and water saturated with Supercritical CO2 (open access)

EGS rock reactions with Supercritical CO2 saturated with water and water saturated with Supercritical CO2

EGS using CO2 as a working fluid will likely involve hydro-shearing low-permeability hot rock reservoirs with a water solution. After that process, the fractures will be flushed with CO2 that is maintained under supercritical conditions (> 70 bars). Much of the injected water in the main fracture will be flushed out with the initial CO2 injection; however side fractures, micro fractures, and the lower portion of the fracture will contain connate water that will interact with the rock and the injected CO2. Dissolution/precipitation reactions in the resulting scCO2/brine/rock systems have the potential to significantly alter reservoir permeability, so it is important to understand where these precipitates form and how are they related to the evolving ‘free’ connate water in the system. To examine dissolution / precipitation behavior in such systems over time, we have conducted non-stirred batch experiments in the laboratory with pure minerals, sandstone, and basalt coupons with brine solution spiked with MnCl2 and scCO2. The coupons are exposed to liquid water saturated with scCO2 and extend above the water surface allowing the upper portion of the coupons to be exposed to scCO2 saturated with water. The coupons were subsequently analyzed using SEM to determine the location of reactions …
Date: February 1, 2013
Creator: Mattson, Earl D.; McLing, Travis L.; Smith, William & Palmer, Carl
Object Type: Article
System: The UNT Digital Library