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The Value of Open Access to Undergraduate Research (open access)

The Value of Open Access to Undergraduate Research

Article describing the importance and value of open access to undergraduate research.
Date: October 1, 2013
Creator: Waugh, Laura & Keralis, Spencer D. C.
Object Type: Article
System: The UNT Digital Library
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
North Texas Daily (Denton, Tex.), Vol. 101, No. 10, Ed. 1 Tuesday, October 1, 2013 (open access)

North Texas Daily (Denton, Tex.), Vol. 101, No. 10, Ed. 1 Tuesday, October 1, 2013

Semiweekly student newspaper from the University of North Texas in Denton, Texas that includes local, state, and campus news along with advertising.
Date: October 1, 2013
Creator: Hill, Nadia
Object Type: Newspaper
System: The Portal to Texas History
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
Defect reaction network in Si-doped InP : numerical predictions. (open access)

Defect reaction network in Si-doped InP : numerical predictions.

This Report characterizes the defects in the defect reaction network in silicon-doped, n-type InP deduced from first principles density functional theory. The reaction network is deduced by following exothermic defect reactions starting with the initially mobile interstitial defects reacting with common displacement damage defects in Si-doped InP until culminating in immobile reaction products. The defect reactions and reaction energies are tabulated, along with the properties of all the silicon-related defects in the reaction network. This Report serves to extend the results for intrinsic defects in SAND 2012-3313: %E2%80%9CSimple intrinsic defects in InP: Numerical predictions%E2%80%9D to include Si-containing simple defects likely to be present in a radiation-induced defect reaction sequence.
Date: October 1, 2013
Creator: Schultz, Peter Andrew
Object Type: Report
System: The UNT Digital Library
Advanced Materials in Support of EERE Needs to Advance Clean Energy Technologies Program Implementation (open access)

Advanced Materials in Support of EERE Needs to Advance Clean Energy Technologies Program Implementation

The goal of this activity was to carry out program implementation and technical projects in support of the ARRA-funded Advanced Materials in Support of EERE Needs to Advance Clean Energy Technologies Program of the DOE Advanced Manufacturing Office (AMO) (formerly the Industrial Technologies Program (ITP)). The work was organized into eight projects in four materials areas: strategic materials, structural materials, energy storage and production materials, and advanced/field/transient processing. Strategic materials included work on titanium, magnesium and carbon fiber. Structural materials included work on alumina forming austentic (AFA) and CF8C-Plus steels. The advanced batteries and production materials projects included work on advanced batteries and photovoltaic devices. Advanced/field/transient processing included work on magnetic field processing. Details of the work in the eight projects are available in the project final reports which have been previously submitted.
Date: October 1, 2013
Creator: Liby, Alan L & Rogers, Hiram
Object Type: Report
System: The UNT Digital Library
Effect of DC voltage pulses on memristor behavior. (open access)

Effect of DC voltage pulses on memristor behavior.

Current knowledge of memristor behavior is limited to a few physical models of which little comprehensive data collection has taken place. The purpose of this research is to collect data in search of exploitable memristor behavior by designing and implementing tests on a HP Labs Rev2 Memristor Test Board. The results are then graphed in their optimal format for conceptualizing behavioral patterns. This series of experiments has concluded the existence of an additional memristor state affecting the behavior of memristors when pulsed with positively polarized DC voltages. This effect has been observed across multiple memristors and data sets. The following pages outline the process that led to the hypothetical existence and eventual proof of this additional state of memristor behavior.
Date: October 1, 2013
Creator: Evans, Brian R.
Object Type: Report
System: The UNT Digital Library
Site Suitability and Hazard Assessment Guide for Small Modular Reactors (open access)

Site Suitability and Hazard Assessment Guide for Small Modular Reactors

Commercial nuclear reactor projects in the U.S. have traditionally employed large light water reactors (LWR) to generate regional supplies of electricity. Although large LWRs have consistently dominated commercial nuclear markets both domestically and abroad, the concept of small modular reactors (SMRs) capable of producing between 30 MW(t) and 900 MW(t) to generating steam for electricity is not new. Nor is the idea of locating small nuclear reactors in close proximity to and in physical connection with industrial processes to provide a long-term source of thermal energy. Growing problems associated continued use of fossil fuels and enhancements in efficiency and safety because of recent advancements in reactor technology suggest that the likelihood of near-term SMR technology(s) deployment at multiple locations within the United States is growing. Many different types of SMR technology are viable for siting in the domestic commercial energy market. However, the potential application of a particular proprietary SMR design will vary according to the target heat end-use application and the site upon which it is proposed to be located. Reactor heat applications most commonly referenced in connection with the SMR market include electric power production, district heating, desalinization, and the supply of thermal energy to various processes that …
Date: October 1, 2013
Creator: Moe, Wayne
Object Type: Report
System: The UNT Digital Library
Bay Ridge Gardens - Mixed Humid Affordable Multifamily Housing Deep Energy Retrofit: Annapolis, Maryland. Building America Case Study: Whole-House Solutions for Existing Homes (Fact Sheet) (open access)

Bay Ridge Gardens - Mixed Humid Affordable Multifamily Housing Deep Energy Retrofit: Annapolis, Maryland. Building America Case Study: Whole-House Solutions for Existing Homes (Fact Sheet)

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: October 1, 2013
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Timing is everything : along the fossil fuel transition pathway. (open access)

Timing is everything : along the fossil fuel transition pathway.

People save for retirement throughout their career because it is virtually impossible to save all you'll need in retirement the year before you retire. Similarly, without installing incremental amounts of clean fossil, renewable or transformative energy technologies throughout the coming decades, a radical and immediate change will be near impossible the year before a policy goal is set to be in place. Therefore, our research question is,<U+2018>To meet our desired technical and policy goals, what are the factors that affect the rate we must install technology to achieve these goals in the coming decades?' Existing models do not include full regulatory constraints due to their often complex, and inflexible approaches to solve for<U+2018>optimal' engineering instead of<U+2018>robust' and multidisciplinary solutions. This project outlines the theory and then develops an applied software tool to model the laboratory-to-market transition using the traditional technology readiness level (TRL) framework, but develops subsequent and a novel regulatory readiness level (RRL) and market readiness level (MRL). This tool uses the ideally-suited system dynamics framework to incorporate feedbacks and time delays. Future energy-economic-environment models, regardless of their programming platform, may adapt this software model component framework or<U+2018>module' to further vet the likelihood of new or innovative technology moving …
Date: October 1, 2013
Creator: Kobos, Peter Holmes; Walker, La Tonya Nicole & Malczynski, Leonard A.
Object Type: Report
System: The UNT Digital Library
First Determination of the Weak Charge of the Proton (open access)

First Determination of the Weak Charge of the Proton

The Qweak experiment has measured the parity-violating asymmetry in polarized e-p elastic scattering at Q^2 = 0.025(GeV/c)^2, employing 145 microamps of 89% longitudinally polarized electrons on a 34.4cm long liquid hydrogen target at Jefferson Lab. The results of the experiment&#x27;s commissioning run are reported here, constituting approximately 4% of the data collected in the experiment. From these initial results the measured asymmetry is A_e_p = -279 +- 35 (statistics) +- 31 (systematics) ppb, which is the smallest and most precise asymmetry ever measured in polarized e-p scattering. The small Q^2 of this experiment has made possible the first determination of the weak charge of the proton, Q^p_W, by incorporating earlier parity-violating electron scattering (PVES) data at higher Q^2 to constrain hadronic corrections. The value of Q^p_W obtained in this way is Q^p_W(PVES) = 0.064 +- 0.012, in good agreement with the Standard Model prediction of Q^p_W(SM) = 0.0710 +- 0.0007. When this result is further combined with the Cs atomic parity violation (APV) measurement, significant constraints on the weak charges of the up and down quarks can also be extracted. That PVES+APV analysis reveals the neutron&#x27;s weak charge to be Q^n_W(PVES+APV) = -0.975 +- 0.010.
Date: October 1, 2013
Creator: Androic, D.; Armstrong, D. S.; Asaturyan, A.; Averett, T.; Balewski, J.; Beaufait, J. et al.
Object Type: Article
System: The UNT Digital Library
Dynamic temperature measurements with embedded optical sensors. (open access)

Dynamic temperature measurements with embedded optical sensors.

This report summarizes LDRD project number 151365, %5CDynamic Temperature Measurements with Embedded Optical Sensors%22. The purpose of this project was to develop an optical sensor capable of detecting modest temperature states (<1000 K) with nanosecond time resolution, a recurring diagnostic need in dynamic compression experiments at the Sandia Z machine. Gold sensors were selected because the visible re ectance spectrum of gold varies strongly with temperature. A variety of static and dynamic measurements were performed to assess re ectance changes at di erent temperatures and pressures. Using a minimal optical model for gold, a plausible connection between static calibrations and dynamic measurements was found. With re nements to the model and diagnostic upgrades, embedded gold sensors seem capable of detecting minor (<50 K) temperature changes under dynamic compression.
Date: October 1, 2013
Creator: Dolan, Daniel H.,; Seagle, Christopher T & Ao, Tommy
Object Type: Report
System: The UNT Digital Library
Computer–Based Procedures for Nuclear Power Plant Field Workers: Preliminary Results from Two Evaluation Studies (open access)

Computer–Based Procedures for Nuclear Power Plant Field Workers: Preliminary Results from Two Evaluation Studies

The Idaho National Laboratory and participants from the U.S. nuclear industry are collaborating on a research effort aimed to augment the existing guidance on computer-based procedure (CBP) design with specific guidance on how to design CBP user interfaces such that they support procedure execution in ways that exceed the capabilities of paper-based procedures (PBPs) without introducing new errors. Researchers are employing an iterative process where the human factors issues and interface design principles related to CBP usage are systematically addressed and evaluated in realistic settings. This paper describes the process of developing a CBP prototype and the two studies conducted to evaluate the prototype. The results indicate that CBPs may improve performance by reducing errors, but may increase the time it takes to complete procedural tasks.
Date: October 1, 2013
Creator: Blanc, Katya L Le & Oxstrand, Johanna H
Object Type: Article
System: The UNT Digital Library
THE DEPLOYABLE FAST-NEUTRON CODED-APERTURE IMAGER: DEMONSTRATION OF LOCATING ONE OR MORE SOURCES IN THREE DIMENSION (open access)

THE DEPLOYABLE FAST-NEUTRON CODED-APERTURE IMAGER: DEMONSTRATION OF LOCATING ONE OR MORE SOURCES IN THREE DIMENSION

None
Date: October 1, 2013
Creator: Hausladen, Paul; Newby, Robert Jason; Liang, J Felix & Blackston, Matthew A
Object Type: Report
System: The UNT Digital Library
Sandia National Laboratories, California proposed CREATE facility environmental baseline survey. (open access)

Sandia National Laboratories, California proposed CREATE facility environmental baseline survey.

Sandia National Laboratories, Environmental Programs completed an environmental baseline survey (EBS) of 12.6 acres located at Sandia National Laboratories/California (SNL/CA) in support of the proposed Collaboration in Research and Engineering for Advanced Technology and Education (CREATE) Facility. The survey area is comprised of several parcels of land within SNL/CA, County of Alameda, California. The survey area is located within T 3S, R 2E, Section 13. The purpose of this EBS is to document the nature, magnitude, and extent of any environmental contamination of the property; identify potential environmental contamination liabilities associated with the property; develop sufficient information to assess the health and safety risks; and ensure adequate protection for human health and the environment related to a specific property.
Date: October 1, 2013
Creator: Catechis, Christopher Spyros
Object Type: Report
System: The UNT Digital Library
Impeller deflection and modal finite element analysis. (open access)

Impeller deflection and modal finite element analysis.

Deflections of an impeller due to centripetal forces are calculated using finite element analysis. The lateral, or out of plane, deflections are an important design consideration for this particular impeller because it incorporates an air bearing with critical gap tolerances. The target gap distance is approximately 10 microns at a rotational velocity of 2500 rpm. The centripetal forces acting on the impeller cause it deflect in a concave fashion, decreasing the initial gap distance as a function of radial position. This deflection is characterized for a previous and updated impeller design for comparative purposes. The impact of design options such as material selection, geometry dimensions, and operating rotational velocity are also explored, followed by a sensitivity study with these parameters bounded by specific design values. A modal analysis is also performed to calculate the impeller's natural frequencies which are desired to be avoided during operation. The finite element modeling techniques continue to be exercised by the impeller design team to address specific questions and evaluate conceptual designs, some of which are included in the Appendix.
Date: October 1, 2013
Creator: Spencer, Nathan A.
Object Type: Report
System: The UNT Digital Library
PVWatts Version 1 Technical Reference (open access)

PVWatts Version 1 Technical Reference

The NREL PVWatts(TM) calculator is a web application developed by the National Renewable Energy Laboratory (NREL) that estimates the electricity production of a grid-connected photovoltaic system based on a few simple inputs. PVWatts combines a number of sub-models to predict overall system performance, and makes several hidden assumptions about performance parameters. This technical reference details the individual sub-models, documents assumptions and hidden parameters, and explains the sequence of calculations that yield the final system performance estimation.
Date: October 1, 2013
Creator: Dobos, A. P.
Object Type: Report
System: The UNT Digital Library
Improving Surface Radiation in a Satellite-Based Physical Model (Poster) (open access)

Improving Surface Radiation in a Satellite-Based Physical Model (Poster)

This poster provides an overview of the solar resource assessment work needed to achieve high penetrations of concentrating solar power or photovoltaics on the grid.
Date: October 1, 2013
Creator: Sengupta, M.; Habte, A. & Gotseff, P.
Object Type: Article
System: The UNT Digital Library
Renewable Energy Finance, Solar Securitization: A Status Report (Fact Sheet) (open access)

Renewable Energy Finance, Solar Securitization: A Status Report (Fact Sheet)

This fact sheet was designed to introduce solar securitization and the activities of NREL and the Solar Access to Public Capital (SAPC) working group to the investment community.
Date: October 1, 2013
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Feasibility and Demonstration of a Cloud-Based RIID Analysis System (open access)

Feasibility and Demonstration of a Cloud-Based RIID Analysis System

None
Date: October 1, 2013
Creator: Wright, Michael C; Sword, Eric D & Younkin, James R
Object Type: Report
System: The UNT Digital Library
Optimizing Hydronic System Performance in Residential Applications (open access)

Optimizing Hydronic System Performance in Residential Applications

Even though new homes constructed with hydronic heat comprise only 3% of the market (US Census Bureau 2009), of the 115 million existing homes in the United States, almost 14 million of those homes (11%) are heated with steam or hot water systems according to 2009 US Census data. Therefore, improvements in hydronic system performance could result in significant energy savings in the US. When operating properly, the combination of a gas-fired condensing boiler with baseboard convectors and an indirect water heater is a viable option for high-efficiency residential space heating in cold climates. Based on previous research efforts, however, it is apparent that these types of systems are typically not designed and installed to achieve maximum efficiency. Furthermore, guidance on proper design and commissioning for heating contractors and energy consultants is hard to find and is not comprehensive. Through modeling and monitoring, CARB sought to determine the optimal combination(s) of components - pumps, high efficiency heat sources, plumbing configurations and controls - that result in the highest overall efficiency for a hydronic system when baseboard convectors are used as the heat emitter. The impact of variable-speed pumps on energy use and system performance was also investigated along with the …
Date: October 1, 2013
Creator: Arena, L. & Faakye, O.
Object Type: Report
System: The UNT Digital Library
Thermochemical plots using JCZS2i piece-wise curve fits. (open access)

Thermochemical plots using JCZS2i piece-wise curve fits.

This report presents plots of specific heat, enthalpy, entropy, and Gibbs free energy for 1439 species in the JCZS2i database. Included in this set of species are 496 condensed-phase species and 943 gas-phase species. The gas phase species contain 80 anions and 112 cations for a total of 192 ions. The JCZS2i database is used in conjunction with the TIGER thermochemical code to predict thermodynamic states from ambient conditions to high temperatures and pressures. Predictions from the TIGER code using the JCZS2i database can be used in shock physics codes where temperatures may be as high as 20,000 K and ions may be present. Such high temperatures were not considered in the original JCZS database, and extrapolations made for these temperatures were unrealistic. For example, specific heat would sometimes go negative at high temperatures which fails the definition of specific heat. The JCZS2i database is a new version of the JCZS database that is being created to address these inaccuracies. The purpose of the current report is to visualize the high temperature extrapolations to insure that the specific heat, enthalpy, entropy, and Gibbs free energy predictions are reasonable up to 20,000 K.
Date: October 1, 2013
Creator: Miller, David L.; Schoof, Justin C. & Hobbs, Michael L.
Object Type: Report
System: The UNT Digital Library
Potential use of battery packs from NCAP tested vehicles. (open access)

Potential use of battery packs from NCAP tested vehicles.

Several large electric vehicle batteries available to the National Highway Traffic Safety Administration are candidates for use in future safety testing programs. The batteries, from vehicles subjected to NCAP crashworthiness testing, are considered potentially damaged due to the nature of testing their associated vehicles have been subjected to. Criteria for safe shipping to Sandia is discussed, as well as condition the batteries must be in to perform testing work. Also discussed are potential tests that could be performed under a variety of conditions. The ultimate value of potential testing performed on these cells will rest on the level of access available to the battery pack, i.e. external access only, access to the on board monitoring system/CAN port or internal electrical access to the battery. Greater access to the battery than external visual and temperature monitoring would likely require input from the battery manufacturer.
Date: October 1, 2013
Creator: Lamb, Joshua & Orendorff, Christopher J.
Object Type: Report
System: The UNT Digital Library
Novel Experiments to Characterize Creep-Fatigue Degradation in VHTR Alloys (open access)

Novel Experiments to Characterize Creep-Fatigue Degradation in VHTR Alloys

It is well known in energy systems that the creep lifetime of high temperature alloys is significantly degraded when a cyclic load is superimposed on components operating in the creep regime. A test method has been developed in an attempt to characterize creep-fatigue behavior of alloys at high temperature. The test imposes a hold time during the tensile phase of a fully reversed strain-controlled low cycle fatigue test. Stress relaxation occurs during the strain-controlled hold period. This type of fatigue stress relaxation test tends to emphasize the fatigue portion of the total damage and does not necessarily represent the behavior of a component in-service well. Several different approaches to laboratory testing of creep-fatigue at 950°C have been investigated for Alloy 617, the primary candidate for application in VHTR heat exchangers. The potential for mode switching in a cyclic test from strain control to load control, to allow specimen extension by creep, has been investigated to further emphasize the creep damage. In addition, tests with a lower strain rate during loading have been conducted to examine the influence of creep damage occurring during loading. Very short constant strain hold time tests have also been conducted to examine the influence of the …
Date: October 1, 2013
Creator: Wright, J. K.; Simpson, J. A.; Carroll, L. J.; Wright, R. N. & Sham, T.-L.
Object Type: Article
System: The UNT Digital Library