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
Summary of Conclusions and Recommendations Drawn from the DeepCWind Scaled Floating Offshore Wind System Test Campaign: Preprint (open access)

Summary of Conclusions and Recommendations Drawn from the DeepCWind Scaled Floating Offshore Wind System Test Campaign: Preprint

The DeepCwind consortium is a group of universities, national labs, and companies funded under a research initiative by the U.S. Department of Energy (DOE) to support the research and development of floating offshore wind power. The two main objectives of the project are to better understand the complex dynamic behavior of floating offshore wind systems and to create experimental data for use in validating the tools used in modeling these systems. In support of these objectives, the DeepCwind consortium conducted a model test campaign in 2011 of three generic floating wind systems, a tension-leg platform (TLP), a spar-buoy (spar), and a semisubmersible (semi). Each of the three platforms was designed to support a 1/50th-scale model of a 5 MW wind turbine and was tested under a variety of wind/wave conditions. The focus of this paper is to summarize the work done by consortium members in analyzing the data obtained from the test campaign and its use for validating the offshore wind modeling tool, FAST.
Date: July 1, 2013
Creator: Robertson, A. N.; Jonkman, J. M.; Masciola, M. D.; Molta, P.; Goupee, A. J.; Coulling, A. J. et al.
Object Type: Article
System: The UNT Digital Library
Transportation Energy Futures Series: Potential for Energy Efficiency Improvement Beyond the Light-Duty-Vehicle Sector (open access)

Transportation Energy Futures Series: Potential for Energy Efficiency Improvement Beyond the Light-Duty-Vehicle Sector

Considerable research has focused on energy efficiency and fuel substitution options for light-duty vehicles, while much less attention has been given to medium- and heavy-duty trucks, buses, aircraft, marine vessels, trains, pipeline, and off-road equipment. This report brings together the salient findings from an extensive review of literature on future energy efficiency options for these non-light-duty modes. Projected activity increases to 2050 are combined with forecasts of overall fuel efficiency improvement potential to estimate the future total petroleum and greenhouse gas (GHG) emissions relative to current levels. This is one of a series of reports produced as a result of the Transportation Energy Futures (TEF) project, a Department of Energy-sponsored multi-agency project initiated to pinpoint underexplored strategies for abating GHGs and reducing petroleum dependence related to transportation.
Date: March 1, 2013
Creator: Vyas, A. D.; Patel, D. M. & Bertram, K. M.
Object Type: Report
System: The UNT Digital Library
Developing Renewable Energy Projects Larger Than 10 MWs at Federal Facilities (Book) (open access)

Developing Renewable Energy Projects Larger Than 10 MWs at Federal Facilities (Book)

To accomplish Federal goals for renewable energy, sustainability, and energy security, large-scale renewable energy projects must be developed and constructed on Federal sites at a significant scale with significant private investment. The U.S. Department of Energy's Federal Energy Management Program (FEMP) helps Federal agencies meet these goals and assists agency personnel navigate the complexities of developing such projects and attract the necessary private capital to complete them. This guide is intended to provide a general resource that will begin to develop the Federal employee's awareness and understanding of the project developer's operating environment and the private sector's awareness and understanding of the Federal environment. Because the vast majority of the investment that is required to meet the goals for large-scale renewable energy projects will come from the private sector, this guide has been organized to match Federal processes with typical phases of commercial project development. The main purpose of this guide is to provide a project development framework to allow the Federal Government, private developers, and investors to work in a coordinated fashion on large-scale renewable energy projects. The framework includes key elements that describe a successful, financially attractive large-scale renewable energy project.
Date: March 1, 2013
Creator: unknown
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
Targeted Energy Efficiency Expert Evaluation (E4) Report: Bannister Federal Complex, Kansas City, MO (open access)

Targeted Energy Efficiency Expert Evaluation (E4) Report: Bannister Federal Complex, Kansas City, MO

This is a final report summarizing the efficiency measures identified, implemented and the analysis of energy savings after implementation.
Date: March 1, 2013
Creator: Goddard, James K.; Fernandez, Nicholas; Underhill, Ronald M. & Gowri, Krishnan
Object Type: Report
System: The UNT Digital Library
GFMC calculations of electromagnetic moments and M1 transitions in A {<=} 9 nuclei (open access)

GFMC calculations of electromagnetic moments and M1 transitions in A {<=} 9 nuclei

We present recent GreenÂ’s function Monte Carlo calculations of magnetic moments and M1 transitions in A{<=}#20;9 nuclei, which include corrections arising from two-body meson-exchange electromagnetic currents. Two-body effects provide significant corrections to the calculated observables, bringing them in excellent agreement with the experimental data. In particular, we find that two body corrections are especially large in the A = 9, T = 3/2 systems, in which they account for up to ~#24; 20% (~#24; 40%) of the total predicted value for the {sup 9}Li ({sup 9}C) magnetic moment.
Date: August 1, 2013
Creator: Pastore, Saori; Pieper, Steven C.; Schiavilla, Rocco & Wiringa, Robert Bruce
Object Type: Article
System: The UNT Digital Library
Atmosphere-Land-Surface Interaction over the Southern Great Plains: Diagnosis of Mechanisms from SGP ARM Data (open access)

Atmosphere-Land-Surface Interaction over the Southern Great Plains: Diagnosis of Mechanisms from SGP ARM Data

Work reported included analysis of pentad (5 day) averaged data, proposal of a hypothesis concerning the key role of the Atlantic Multi-decadal Oscillation in 20th century drought and wet periods over the Great Plains, analysis of recurrent super-synoptic evolution of the Great Plains low-level jet, and study of pentad evolution of the 1988 drought and 1993 flood over the Great Plains from a NARR perspective on the atmospheric and terrestrial water balance.
Date: February 1, 2013
Creator: Nigam, Sumant
Object Type: Report
System: The UNT Digital Library
Y-12 Groundwater Protection Program Monitoring Optimization Plan For Groundwater Monitoring Wells At The U.S. Department Of Energy Y-12 National Security Complex, Oak Ridge, Tennessee (open access)

Y-12 Groundwater Protection Program Monitoring Optimization Plan For Groundwater Monitoring Wells At The U.S. Department Of Energy Y-12 National Security Complex, Oak Ridge, Tennessee

This document is the monitoring optimization plan for groundwater monitoring wells associated with the U.S. Department of Energy (DOE) Y-12 National Security Complex (Y-12) in Oak Ridge, Tennessee. The plan describes the technical approach that is implemented under the Y-12 Groundwater Protection Program (GWPP) to focus available resources on the monitoring wells at Y-12 that provide the most useful hydrologic and groundwater quality monitoring data. The technical approach is based on the GWPP status designation for each well. Under this approach, wells granted �active� status are used by the GWPP for hydrologic monitoring and/or groundwater quality sampling, whereas wells granted �inactive� status are not used for either purpose. The status designation also defines the frequency at which the GWPP will inspect applicable wells, the scope of these well inspections, and extent of any maintenance actions initiated by the GWPP. Details regarding the ancillary activities associated with implementation of this plan (e.g., well inspection) are deferred to the referenced GWPP plans. This plan applies to groundwater wells associated with Y-12 and related waste management areas and facilities located within three hydrogeologic regimes.
Date: September 1, 2013
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Communication Requirements and Concept of Operation for Sensor Networks (open access)

Communication Requirements and Concept of Operation for Sensor Networks

This report examines the communication requirements and an operation concept for wireless sensor networks in a NPP environment. Specifically, this report addresses the necessary power required for each sensor network node, the transmission frequency, network architecture, capabilities required in each sensor network node, a general of operation including "normal" and "off-normal" conditions,
Date: September 1, 2013
Creator: Clayton, Dwight A
Object Type: Report
System: The UNT Digital Library
DISFRAC Version 2.0 Users Guide (open access)

DISFRAC Version 2.0 Users Guide

DISFRAC is the implementation of a theoretical, multi-scale model for the prediction of fracture toughness in the ductile-to-brittle transition temperature (DBTT) region of ferritic steels. Empirically-derived models of the DBTT region cannot legitimately be extrapolated beyond the range of existing fracture toughness data. DISFRAC requires only tensile properties and microstructural information as input, and thus allows for a wider range of application than empirical, toughness data dependent models. DISFRAC is also a framework for investigating the roles of various microstructural and macroscopic effects on fracture behavior, including carbide particle sizes, grain sizes, strain rates, and material condition. DISFRAC s novel approach is to assess the interaction effects of macroscopic conditions (geometry, loading conditions) with variable microstructural features on cleavage crack initiation and propagation. The model addresses all stages of the fracture process, from microcrack initiation within a carbide particle, to propagation of that crack through grains and across grain boundaries, finally to catastrophic failure of the material. The DISFRAC procedure repeatedly performs a deterministic analysis of microcrack initiation and propagation within a macroscopic crack plastic zone to calculate a critical fracture toughness value for each microstructural geometry set. The current version of DISFRAC, version 2.0, is a research code for …
Date: January 1, 2013
Creator: Cochran, Kristine B; Erickson, Marjorie A; Williams, Paul T; Klasky, Hilda B & Bass, Bennett Richard
Object Type: Report
System: The UNT Digital Library
Breakeven Prices for Photovoltaics on Supermarkets in the United States (open access)

Breakeven Prices for Photovoltaics on Supermarkets in the United States

The photovoltaic (PV) breakeven price is the PV system price at which the cost of PV-generated electricity equals the cost of electricity purchased from the grid. This point is also called 'grid parity' and can be expressed as dollars per watt ($/W) of installed PV system capacity. Achieving the PV breakeven price depends on many factors, including the solar resource, local electricity prices, customer load profile, PV incentives, and financing. In the United States, where these factors vary substantially across regions, breakeven prices vary substantially across regions as well. In this study, we estimate current and future breakeven prices for PV systems installed on supermarkets in the United States. We also evaluate key drivers of current and future commercial PV breakeven prices by region. The results suggest that breakeven prices for PV systems installed on supermarkets vary significantly across the United States. Non-technical factors -- including electricity rates, rate structures, incentives, and the availability of system financing -- drive break-even prices more than technical factors like solar resource or system orientation. In 2020 (where we assume higher electricity prices and lower PV incentives), under base-case assumptions, we estimate that about 17% of supermarkets will be in utility territories where breakeven …
Date: March 1, 2013
Creator: Ong, S.; Clark, N.; Denholm, P. & Margolis, R.
Object Type: Report
System: The UNT Digital Library
New Structural-Dynamics Module for Offshore Multimember Substructures within the Wind Turbine Computer-Aided Engineering Tool FAST: Preprint (open access)

New Structural-Dynamics Module for Offshore Multimember Substructures within the Wind Turbine Computer-Aided Engineering Tool FAST: Preprint

FAST, developed by the National Renewable Energy Laboratory (NREL), is a computer-aided engineering (CAE) tool for aero-hydro-servo-elastic analysis of land-based and offshore wind turbines. This paper discusses recent upgrades made to FAST to enable loads simulations of offshore wind turbines with fixed-bottom, multimember support structures (e.g., jackets and tripods, which are commonly used in transitional-depth waters). The main theory and strategies for the implementation of the multimember substructure dynamics module (SubDyn) within the new FAST modularization framework are introduced. SubDyn relies on two main engineering schematizations: 1) a linear frame finite-element beam (LFEB) model and 2) a dynamics system reduction via Craig-Bampton's method. A jacket support structure and an offshore system consisting of a turbine atop a jacket substructure were simulated to test the SubDyn module and to preliminarily assess results against results from a commercial finite-element code.
Date: August 1, 2013
Creator: Song, H.; Damiani, R.; Robertson, A. & Jonkman, J.
Object Type: Article
System: The UNT Digital Library
Development of Novel RTP-like Processing for Solar Cell Fabrication using UV-Rich Light Sources: Cooperative Research and Development Final Report, CRADA No. CRD-11-442 (open access)

Development of Novel RTP-like Processing for Solar Cell Fabrication using UV-Rich Light Sources: Cooperative Research and Development Final Report, CRADA No. CRD-11-442

NREL and Mattson Technology are interested in developing new processing techniques for fabrication of solar cells using UV-rich optical processing. UV light has a very high absorption coefficient in most semiconductors, allowing the semiconductor surface to be heated locally and, in some cases, without a significant increase in the substrate temperature. NREL has several projects related to cell processing that currently use an optical furnace (having a spectrum rich in visible and infrared light). Mattson Technology has developed a UV rich light source that can be used in either pulse or continuous modes. The objective of this CRADA is to explore applications in solar cell processing where absorption characteristics of UV light can lead to lower cell cost and/or higher efficiencies.
Date: January 1, 2013
Creator: Sopori, B.
Object Type: Report
System: The UNT Digital Library
Brine flow in heated geologic salt. (open access)

Brine flow in heated geologic salt.

This report is a summary of the physical processes, primary governing equations, solution approaches, and historic testing related to brine migration in geologic salt. Although most information presented in this report is not new, we synthesize a large amount of material scattered across dozens of laboratory reports, journal papers, conference proceedings, and textbooks. We present a mathematical description of the governing brine flow mechanisms in geologic salt. We outline the general coupled thermal, multi-phase hydrologic, and mechanical processes. We derive these processes' governing equations, which can be used to predict brine flow. These equations are valid under a wide variety of conditions applicable to radioactive waste disposal in rooms and boreholes excavated into geologic salt.
Date: March 1, 2013
Creator: Kuhlman, Kristopher L. & Malama, Bwalya
Object Type: Report
System: The UNT Digital Library
Turbine Reliability and Operability Optimization through the use of Direct Detection Lidar Final Technical Report (open access)

Turbine Reliability and Operability Optimization through the use of Direct Detection Lidar Final Technical Report

The goal of this Department of Energy (DOE) project is to increase wind turbine efficiency and reliability with the use of a Light Detection and Ranging (LIDAR) system. The LIDAR provides wind speed and direction data that can be used to help mitigate the fatigue stress on the turbine blades and internal components caused by wind gusts, sub-optimal pointing and reactionary speed or RPM changes. This effort will have a significant impact on the operation and maintenance costs of turbines across the industry. During the course of the project, Michigan Aerospace Corporation (MAC) modified and tested a prototype direct detection wind LIDAR instrument; the resulting LIDAR design considered all aspects of wind turbine LIDAR operation from mounting, assembly, and environmental operating conditions to laser safety. Additionally, in co-operation with our partners, the National Renewable Energy Lab and the Colorado School of Mines, progress was made in LIDAR performance modeling as well as LIDAR feed forward control system modeling and simulation. The results of this investigation showed that using LIDAR measurements to change between baseline and extreme event controllers in a switching architecture can reduce damage equivalent loads on blades and tower, and produce higher mean power output due to fewer …
Date: February 1, 2013
Creator: Johnson, David K.; Lewis, Matthew J.; Pavlich, Jane C.; Wright, Alan D.; Johnson, Kathryn E. & Pace, Andrew M.
Object Type: Report
System: The UNT Digital Library

Addressing the Impact of Temperature Extremes on Large Format Li-Ion Batteries for Vehicle Applications

This presentation discusses the effects of temperature on large format lithium-ion batteries in electric drive vehicles.
Date: May 1, 2013
Creator: Pesaran, A.; Santhanagopalan, S. & Kim, G. H.
Object Type: Presentation
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
Acquiring Impedance Spectra From Diode-Coupled Primary Batteries to Determine Health and State of Charge (open access)

Acquiring Impedance Spectra From Diode-Coupled Primary Batteries to Determine Health and State of Charge

The U.S. Army uses BA5590 Lithium Sulfur Dioxide p
Date: March 1, 2013
Creator: Morrison, John L.; Christophersen, Jon P. & Morrison, William H.
Object Type: Article
System: The UNT Digital Library

Novel Scanning Lens Instrument for Evaluating Fresnel Lens Performance: Equipment Development and Initial Results

A system dedicated to the optical transmittance characterization of Fresnel lenses has been developed at NREL, in collaboration with the UPM. The system quantifies the optical efficiency of the lens by generating a performance map. The shape of the focused spot may also be analyzed to understand change in the lens performance. The primary instrument components (lasers and CCD detector) have been characterized to confirm their capability for performing optical transmittance measurements. Measurements performed on SoG and PMMA lenses subject to a variety of indoor conditions (e.g., UV and damp heat) identified differences in the optical efficiency of the evaluated lenses, demonstrating the ability of the Scanning Lens Instrument (SLI) to distinguish between the aged lenses.
Date: July 1, 2013
Creator: Herrero, R.; Miller, D. C.; Kurtz, S. R.; Anton, I. & Sala, G.
Object Type: Presentation
System: The UNT Digital Library
Mechanical Properties of Nuclear Fuel Surrogates using Picosecond Laser Ultrasonics (open access)

Mechanical Properties of Nuclear Fuel Surrogates using Picosecond Laser Ultrasonics

Detailed understanding between microstructure evolution and mechanical properties is important for designing new high burnup nuclear fuels. In this presentation we discuss the use of picosecond ultrasonics to measure localize changes in mechanical properties of fuel surrogates. We develop measurement techniques that can be applied to investigate heterogeneous elastic properties caused by localize changes in chemistry, grain microstructure caused by recrystallization, and mechanical properties of small samples prepared using focused ion beam sample preparation. Emphasis is placed on understanding the relationship between microstructure and mechanical properties
Date: May 1, 2013
Creator: Hurley, David; Khafizov, Marat; Farzbod, Farhad & Burgett, Eric
Object Type: Article
System: The UNT Digital Library
NONLINEAR DIFFUSION ACCELERATION FOR THE MULTIGROU (open access)

NONLINEAR DIFFUSION ACCELERATION FOR THE MULTIGROU

Nonlinear diffusion acceleration (NDA) can improve
Date: May 1, 2013
Creator: Wang, Yaqi
Object Type: Article
System: The UNT Digital Library
A novel laser-based approach for cleaning contamin (open access)

A novel laser-based approach for cleaning contamin

We are developing a novel approach for cleaning an
Date: May 1, 2013
Creator: Fox, Robert V.; Roberts, Lauren & Frank C. DeLucia, J
Object Type: Article
System: The UNT Digital Library
Intra-membrane molecular interactions of K%2B channel proteins : application to problems in biodefense and bioenergy. (open access)

Intra-membrane molecular interactions of K%2B channel proteins : application to problems in biodefense and bioenergy.

Ion channel proteins regulate complex patterns of cellular electrical activity and ionic signaling. Certain K+ channels play an important role in immunological biodefense mechanisms of adaptive and innate immunity. Most ion channel proteins are oligomeric complexes with the conductive pore located at the central subunit interface. The long-term activity of many K+ channel proteins is dependent on the concentration of extracellular K+; however, the mechanism is unclear. Thus, this project focused on mechanisms underlying structural stability of tetrameric K+ channels. Using KcsA of Streptomyces lividans as a model K+ channel of known structure, the molecular basis of tetramer stability was investigated by: 1. Bioinformatic analysis of the tetramer interface. 2. Effect of two local anesthetics (lidocaine, tetracaine) on tetramer stability. 3. Molecular simulation of drug docking to the ion conduction pore. The results provide new insights regarding the structural stability of K+ channels and its possible role in cell physiology.
Date: July 1, 2013
Creator: Moczydlowski, Edward G.
Object Type: Report
System: The UNT Digital Library