Fundamental and magnetic-hardening studies of nanocrystalline and nanocomposite magnets. Final technical report (open access)

Fundamental and magnetic-hardening studies of nanocrystalline and nanocomposite magnets. Final technical report

In this project the authors study new nanocrystalline and nanocomposite structures that have high potential for permanent-magnet development. These materials, which can be synthesized to have either very high or intermediate coercivities, have many applications in electric power, transportation, and information-storage industries. There is great interest in further development of understanding and application of these materials. Brief discussions are given for the following research highlights: (A) Fundamental electronic, magnetic and micromagnetic studies; (B) Intrinsic and magnet hardening studies of carbides and alloys; and (C) Nanostructured and nanocomposite films.
Date: December 19, 1998
Creator: Sellmyer, D.J. & Hadjipanayis, G.C.
Object Type: Report
System: The UNT Digital Library
Analyses of a Reinforced Concrete Containment with Liner Corrosion Damage (open access)

Analyses of a Reinforced Concrete Containment with Liner Corrosion Damage

Incidents of liner corrosion in nuclear power containment structures have been recorded. These incidents and concerns of other possible liner corrosion in containment have prompted an interest in determining g the capacity of a degraded containment. Finite element analyses of a typical pressurized water reactor (PWR) reinforced concrete containment with liner corrosion were conducted using the A13AQUS finite element code with the ANACAP-U nonlinear concrete constitutive model. The effect of liner corrosion on containment capacity was investigated. A loss of coolant accident was simulated by applying pressure and temperature changes to the structure without corrosion to determine baseline failure limits, followed by multiple analyses of the containment with corrosion at different locations and varying degrees of liner degradation. The corrosion locations were chosen at the base of the containment wall, near the equipment hatch, and at the midheight of the containment wall. Using a strain-based failure criterion the different scenarios were evaluated to prioritize their effect on containment capacity
Date: November 19, 1998
Creator: Cherry, J. L. & Smith, J. A.
Object Type: Article
System: The UNT Digital Library
CALGRID Photochemical Modeling of Air Quality Impacts of Alternative Transportation Fuel Use in Los Angeles (open access)

CALGRID Photochemical Modeling of Air Quality Impacts of Alternative Transportation Fuel Use in Los Angeles

The National Renewable Energy Laboratory has been conducting a comprehensive program to quantify and assess the air quality impacts of the emissions of ozone precursors, air toxins, and greenhouse gases from alternative fuel vehicles. This program includes both an emissions estimation component and a photochemical modeling component to study three fuels: reformulated gasoline, compressed natural gas, and 85% methanol (M85). This report describes the use of the CALGRID model in the Los Angeles modeling domain using the State-Wide Air Pollution Research Center (SAPRC90) chemical mechanism and an early version of the SAPRC93 mechanism. A variety of conclusions can be drawn from the results of this study, including results from chemical mechanism testing; development of meteorological inputs; model evaluation and comparison; and the analyses of the impacts of the emissions scenarios. The report summarizes the study's major findings in these areas.
Date: November 19, 1998
Creator: Moore, G. E.; Londergan, R. J. & Fernau, M. E.
Object Type: Report
System: The UNT Digital Library
Code Development for Control Design Applications: Phase I: Structural Modeling (open access)

Code Development for Control Design Applications: Phase I: Structural Modeling

The design of integrated controls for a complex system like a wind turbine relies on a system model in an explicit format, e.g., state-space format. Current wind turbine codes focus on turbine simulation and not on system characterization, which is desired for controls design as well as applications like operating turbine model analysis, optimal design, and aeroelastic stability analysis. This paper reviews structural modeling that comprises three major steps: formation of component equations, assembly into system equations, and linearization.
Date: November 19, 1998
Creator: Bir, G. S. & Robinson, M.
Object Type: Article
System: The UNT Digital Library
Determination of the Built-in Electric Field near Contacts to Polycrystalline CuInSe{sub 2} - Probing Local Charge Transport Properties by Photomixing (open access)

Determination of the Built-in Electric Field near Contacts to Polycrystalline CuInSe{sub 2} - Probing Local Charge Transport Properties by Photomixing

The built-in electric field in polycrystalline CuInSe{sub 2} (CIS) near gold co-planar contacts was quantitatively revealed for the first time by the photomixing technique. A He-Ne laser beam was focused locally on the CIS sample near one of its contact. While both dc dark and photo-currents showed ohmic behavior, the high frequency ac current was non-zero for zero applied dc bias, which reveals a built-in electric field of {approx}1000V/cm. The capability of the photomixing technique to probe local charge transport properties is expected to be very useful for, e.g., the quantitative evaluation of the quality of ohmic contacts and the investigation of electric field induced p-n junction formation in CIS and related materials.
Date: November 19, 1998
Creator: Tang, Y.; Dong, S.; Sun, G. S.; Braunstein, R. & von Roedern, B.
Object Type: Article
System: The UNT Digital Library
Development of A Thin Film Crystalline Silicon Solar Cell (open access)

Development of A Thin Film Crystalline Silicon Solar Cell

A new design for a single junction, thin film Si solar cell is presented. The cell design is compatible with low-temperature processing required for the use of a low-cost glass substrate, and includes effective light trapping and impurity gettering. Elements of essential process steps are discussed.
Date: November 19, 1998
Creator: Sopori, B.; Chen, W. & Zhang, Y.
Object Type: Article
System: The UNT Digital Library
Evaluation of 241-AZ tank farm supporting phase 1 privatization waste feed delivery (open access)

Evaluation of 241-AZ tank farm supporting phase 1 privatization waste feed delivery

This evaluation is one in a series of evaluations determining the process needs and assessing the adequacy of existing and planned equipment in meeting those needs at various double-shell tank farms in support of Phase 1 privatization. A number of tank-to-tank transfers and waste preparation activities are needed to process and feed waste to the private contractor in support of Phase 1 privatization. The scope of this evaluation is limited to process needs associated with 241-AZ tank farm during the Phase 1 privatization.
Date: November 19, 1998
Creator: Carlson, A. B.
Object Type: Report
System: The UNT Digital Library
Grid-Connected Wind Energy Technology: Progress and Prospects (open access)

Grid-Connected Wind Energy Technology: Progress and Prospects

This paper discusses wind energy markets, technology & industry status, and U.S. market trends.
Date: November 19, 1998
Creator: Parsons, B.
Object Type: Article
System: The UNT Digital Library
Motor Challenge Turning Point, November 1998 (open access)

Motor Challenge Turning Point, November 1998

The November 1998 of Turning Point highlights the US Industrial Electric Motor Systems Market Opportunities Assessment Report--the first of its kind in 20 years. Sponsored by DOE's Motor Challenge Program, the comprehensive assessment describes motor-system use in the industrial sector. This issue also introduces the latest version of MotorMaster+ motor management software-- MotorMaster+ 3.0, and includes a case study on a fan system optimization project that yielded significant energy and cost savings for a Louisiana-Pacific plant.
Date: November 19, 1998
Creator: unknown
Object Type: Book
System: The UNT Digital Library
On the Use of Reanalysis Data for Wind Resource Assessment (open access)

On the Use of Reanalysis Data for Wind Resource Assessment

The goal of the U.S. Department of Energy (DOE) Wind Energy Program's wind resource assessment group located at the National Renewable Energy Laboratory (NREL) in Golden, Colorado, is to improve the characterization of the wind resource in many regions of the world in support of the U.S. wind energy industry. NREL characterizes the level of the available wind resource at wind turbine hub heights (typically 30 m to 50 m above ground level) using wind power density, expressed in units of Watts per square meter. Wind power density values are frequently used to classify the wind resource level with the higher wind power classes assigned to areas with high power density values. NREL has developed a wind assessment methodology to produce wind resource maps useful for wind prospecting and wind energy project implementation. The methodology integrates information from global climatic data sets and also involves a critical meteorologic analysis of the climatic data. It is in the context of the critical meteorological analysis and the automated mapping system that we plan to evaluate the usefulness of Reanalysis data for wind assessment purposes.
Date: November 19, 1998
Creator: Schwartz, M. N. & George, R. L.
Object Type: Article
System: The UNT Digital Library
Overcoming the Efficiency-Limiting Mechanisms in Commercial Si Solar Cells (open access)

Overcoming the Efficiency-Limiting Mechanisms in Commercial Si Solar Cells

A brief review of performance-limiting processes in a commercial solar cell fabricated on low-cost substrate is given. Higher efficiencies require effective gettering of precipitated impurities present at the defect clusters, and improved cell and process designs. Overcoming these limitations is expected to lead to 18%-20% cell efficiencies.
Date: November 19, 1998
Creator: Sopori, B.; Chen, W. (National Renewable Energy Laboratory); Tan, T. & Plekhanov, P. (Duke University, Raleigh, NC)
Object Type: Article
System: The UNT Digital Library
Particulate Measurements and Emissions Characterization of Alternative Fuel Vehicle Exhaust (open access)

Particulate Measurements and Emissions Characterization of Alternative Fuel Vehicle Exhaust

The objective of this project was to measure and characterize particulate emissions from light-duty alternative fuel vehicles (AFVs) and equivalent gasoline-fueled vehicles. The project included emission testing of a fleet of 129 gasoline-fueled vehicles and 19 diesel vehicles. Particulate measurements were obtained over Federal Test Procedure and US06 cycles. Chemical characterization of the exhaust particulate was also performed. Overall, the particulate emissions from modern technology compressed natural gas and methanol vehicles were low, but were still comparable to those of similar technology gasoline vehicles.
Date: November 19, 1998
Creator: Durbin, T. D.; Truex, T. J. & Norbeck, J. M. (Center for Environmental Research and Technology College of Engineering, University of California - Riverside, California)
Object Type: Report
System: The UNT Digital Library
Request for modification of 200 Area effluent treatment facility final delisting (open access)

Request for modification of 200 Area effluent treatment facility final delisting

A Delisting Petition submitted to the U.S. Environmental Protection Agency in August 1993 addressed effluent to be generated at the 200 Area Effluent Treatment Facility from treating Hanford Facility waste streams. This Delisting Petition requested that 71.9 million liters per year of treated effluent, bearing the designation 'F001' through 'F005', and/or 'F039' that is derived from 'F001' through 'F005' waste, be delisted. On June 13, 1995, the U.S. Environmental Protection Agency published the final rule (Final Delisting), which formally excluded 71.9 million liters per year of 200 Area Effluent Treatment Facility effluent from ''being listed as hazardous wastes'' (60 FR 31115 now promulgated in 40 CFR 261). Given the limited scope, it is necessary to request a modification of the Final Delisting to address the management of a more diverse multi-source leachate (F039) at the 200 Area Effluent Treatment Facility. From past operations and current cleanup activities on the Hanford Facility, a considerable amount of both liquid and solid Resource Conservation and Recovery Act of 1976 regulated mixed waste has been and continues to be generated. Ultimately this waste will be treated as necessary to meet the Resource Conservation and Recovery Act Land Disposal Restrictions. The disposal of this waste …
Date: November 19, 1998
Creator: BOWMAN, R.C.
Object Type: Report
System: The UNT Digital Library
SLURRY PHASE IRON CATALYSTS FOR INDIRECT COAL LIQUEFACTION (open access)

SLURRY PHASE IRON CATALYSTS FOR INDIRECT COAL LIQUEFACTION

This report describes research conducted to support the DOE program in indirect coal liquefaction. Specifically, they have studied the attrition behavior of iron Fischer-Tropsch catalysts, their interaction with the silica binder and the evolution of iron phases in a synthesis gas conversion process. The results provide significant insight into factors that should be considered in the design of catalysts for converting coal based syngas into liquid fuels.
Date: November 19, 1998
Creator: Datye, Abhaya K.
Object Type: Report
System: The UNT Digital Library
Surface Analytical Study of CuInSe2 Treated in Cd-Containing Partial Electrolyte Solution (open access)

Surface Analytical Study of CuInSe2 Treated in Cd-Containing Partial Electrolyte Solution

Junction formation in CuInSe2 (CIS) has been studied by exposing thin films and single-crystal samples to solutions containing NH4OH and CdSO4. The treated samples were analyzed by secondary ion mass spectrometry to determine the amount and distribution of Cd deposited on the surface of the films. Cadmium is found to react with the surface for all the solution exposure times and temperatures studied. The reaction rapidly approaches the endpoint and remains relatively unchanged for subsequent solution exposure. Cadmium in-diffusion, as measured by secondary ion mass spectrometry, is obscured by topography effects in the thin-film samples and by ion-beam mixing and topography in the single-crystal sample.
Date: November 19, 1998
Creator: Asher, S. E.; Ramanathan, K.; H., Wiesner; Moutinho, H. (National Renewable Energy Laboratory) & Niles, D. W. (Hewlett-Packard Corporation)
Object Type: Article
System: The UNT Digital Library
Tank 241-TX-118, core 236 analytical results for the final report (open access)

Tank 241-TX-118, core 236 analytical results for the final report

This document is the analytical laboratory report for tank 241-TX-118 push mode core segments collected between April 1, 1998 and April 13, 1998. The segments were subsampled and analyzed in accordance with the Tank 241-TX-118 Push Mode Core sampling and Analysis Plan (TSAP) (Benar, 1997), the Safety Screening Data Quality Objective (DQO) (Dukelow, et al., 1995), the Data Quality Objective to Support Resolution of the Organic Complexant Safety Issue (Organic DQO) (Turner, et al, 1995) and the Historical Model Evaluation Data Requirements (Historical DQO) (Sipson, et al., 1995). The analytical results are included in the data summary table (Table 1). None of the samples submitted for Differential Scanning Calorimetry (DSC) and Total Organic Carbon (TOC) exceeded notification limits as stated in the TSAP (Benar, 1997). One sample exceeded the Total Alpha Activity (AT) analysis notification limit of 38.4{micro}Ci/g (based on a bulk density of 1.6), core 236 segment 1 lower half solids (S98T001524). Appropriate notifications were made. Plutonium 239/240 analysis was requested as a secondary analysis. The statistical results of the 95% confidence interval on the mean calculations are provided by the Tank Waste Remediation Systems Technical Basis Group in accordance with the Memorandum of Understanding (Schreiber, 1997) and are …
Date: November 19, 1998
Creator: Esch, Ruth A.
Object Type: Report
System: The UNT Digital Library
Thin Film Photovoltaics (open access)

Thin Film Photovoltaics

The motivation to develop thin film technologies dates back to the inception of photovoltaics. It is an idea based on achieving truly low-cost photovoltaics appropriate for mass production and energy significant markets. The key to the idea is the use of pennies worth of active materials. Since sunlight carries relatively little energy in comparison with combustion-based energy sources, photovoltaic (PV) modules must be cheap to produce energy that can be competitive. Thin films are presumed to be the answer to that low-cost requirement. But how cheap do they have to be? The following is an oversimplified analysis that allows some insight into this question.
Date: November 19, 1998
Creator: Zweibel, K.
Object Type: Article
System: The UNT Digital Library
Validation of a Model for a Two-Bladed Flexible Rotor System: Progress to Date (open access)

Validation of a Model for a Two-Bladed Flexible Rotor System: Progress to Date

At the National Renewable Energy Laboratory, we tested a very flexible wind turbine. This machine, the Cannon Wind Eagle turbine, exhibited an ability to significantly reduce the rotor flap-wise bending moments through a unique combination of a flexible rotor and hub design. In parallel to this testing effort, we developed analytical models of this machine using our simulation codes. The goal of this work was to validate the analytical models of this machine by comparing analytical predictions to measured results from the real machine. We first describe briefly the simulation codes used in this study. We then describe the wind turbine we analyzed. We then describe analytical model validation progress for this flexible rotor and show preliminary validation results. Finally, we make conclusions and state our plans for future studies.
Date: November 19, 1998
Creator: Wright, A. D.; Kelley, N. D. & Osgood, R. M.
Object Type: Article
System: The UNT Digital Library
Application of 2-D Simulations to Z-Pinch Experiment Design and Analysis (open access)

Application of 2-D Simulations to Z-Pinch Experiment Design and Analysis

The successful 2-D simulations of z-pinch experiments (reproducing such features as the measured experimental current drive, radiation pulse shape, peak power and total radiated energy) can lead to a better understanding of the underlying physics in z-pinch implosions and to the opportunity to use such simulations in the analysis of experimental data and in the design of new experiments. Such use has been made with LANL simulations of experiments on the Sandia Saturn and Z accelerators. Applications have included ''vacuum'' and ''dynamic'' hohlraum experiments; variations in mass, radius and length; and ''nested'' array configurations. Notable examples include the explanation of the power/length results in reduced length pinches and the prediction of the current best power and pulsewidth nested array experiment. Examples of circumstances where the simulation results do not match the experiments will be given along with a discussion of opportunities for improved simulation results.
Date: October 19, 1998
Creator: Peterson, D. L.; Bowers, R. L.; Matuska, W.; Chandler, G. A.; Deeney, C.; Derzon, M. S. et al.
Object Type: Article
System: The UNT Digital Library
Basis for Interim Operation for the K-Reactor in Cold Standby (open access)

Basis for Interim Operation for the K-Reactor in Cold Standby

The Basis for Interim Operation (BIO) document for K Reactor in Cold Standby and the L- and P-Reactor Disassembly Basins was prepared in accordance with the draft DOE standard for BIO preparation (dated October 26, 1993).
Date: October 19, 1998
Creator: Shedrow, B.
Object Type: Report
System: The UNT Digital Library
Conformational Diversity in (Octaethylporphinato) (trichloroacetato)iron(III) Derivatives (open access)

Conformational Diversity in (Octaethylporphinato) (trichloroacetato)iron(III) Derivatives

Treatment of [Fe(OEP)]20 with trichloroacetic acid results in ruffled formation of (octaethylporphinato trichloroacetato)iron(HI). Various crystalline solvates can be isolated, depending on the crystallization solvent. Initial crystallization with CHC13/hexanes resulted in the isolation of an unsolvated form. [Fe(OEP)(02C2C13 )]. This form contains distinct porphyrin core conformations at the same site: one is domed and the other is ruffled. Crystal data for [Fe(OEP)(02C2C13 )]: Q = 14.734(4) .4. b = 13.674(1) .\. c = 17..541 [,.5] .~. 3 = 90.67(1)0, V = 35-!5.8(14) .\3. monoclinic. space group R1/ n. Z = 4. Subsequent crystallization with CHC13/hexanes resulted in a new crystalline form, [Fe(OEP)(OzC2C13 )~.- CHC13; the porphyrin core is slightly ruffled. Crystal data for [Fe(OEP)(OoC2C13 )]. CHC13: a =12.323(1) .~, 6 = 13.062(3) .\. C = 14.327(2) .$, Q = 89.32(1)", .3 = 113.36(2)0. :~ = 105.26(1)'. V = `2031.3(6) .\3. triclinic. space group Pi. Z = 2. Crystallization with CH2C12/hexanes resulted in the isolation of yet another form, [Fe(OEP) (02 C2C13)]. H02C2C13. which contains two independent molecules in the unit cell: molecule is slightly saddled and molecule B is modestly ruffled. Crystal data for [Fe(OEP)(02ClC13 )]. H02C2C13: a = 13.148(3) .\, b = 13.45.5(3) A, c = Q3.761(5) -& ~ = …
Date: October 19, 1998
Creator: Cheng, B.; Ma, J.; Neal, T.J.; Scheidt, W.R.; Schulz, C.E. & Shelnutt, J.A.
Object Type: Article
System: The UNT Digital Library
Design of high density gamma-phase uranium alloys for LEU dispersion fuel applications. (open access)

Design of high density gamma-phase uranium alloys for LEU dispersion fuel applications.

Uranium alloys are candidates for the fuel phase in aluminum matrix dispersion fuels requiring high uranium loading. Certain uranium alloys have been shown to have good irradiation performance at intermediate burnup. Previous studies have shown that acceptable fission gas swelling behavior and fuel-aluminum interaction is possible only if the fuel alloy can be maintained in the high temperature body-centered-cubic {gamma}-phase during fabrication and irradiation, i.e., at temperatures at which {alpha}-U is the equilibrium phase. Transition metals in Groups V through VIII are known to allow metastable retention of the gamma phase below the equilibrium isotherm. These metals have varying degrees of effectiveness in stabilizing the gamma phase. Certain alloys are metastable for very long times at the relatively low fuel temperatures seen in research reactor operation. In this paper, the existing data on the gamma stability of binary and ternary uranium alloys is analyzed. The mechanism and kinetics of decomposition of the gamma phase are assessed with the help of metal alloy theory. Alloys with the highest possible uranium content, good gamma-phase stability, and good neutronic performance are identified for further metallurgical studies and irradiation tests. Results from theory will be compared with experimentally generated data.
Date: October 19, 1998
Creator: Hofman, G. L.
Object Type: Article
System: The UNT Digital Library
Domain decomposition methods for parallel laser-tissue models with Monte Carlo transport (open access)

Domain decomposition methods for parallel laser-tissue models with Monte Carlo transport

Achieving parallelism in simulations that use Monte Carlo transport methods presents interesting challenges. For problems that require domain decomposition, load balance can be harder to achieve. The Monte Carlo transport package may have to operate with other packages that have different optimal domain decompositions for a given problem. To examine some of these issues, we have developed a code that simulates the interaction of a laser with biological tissue; it uses a Monte Carlo method to simulate the laser and a finite element model to simulate the conduction of the temperature field in the tissue. We will present speedup and load balance results obtained for a suite of problems decomposed using a few domain decomposition algorithms we have developed.
Date: October 19, 1998
Creator: Alme, H.J.; Rodrique, G. & Zimmerman, G.
Object Type: Article
System: The UNT Digital Library
Economics and the evaluation of publicly funded energy R and D (open access)

Economics and the evaluation of publicly funded energy R and D

There are three major areas in which economics can contribute to the evaluation of federal R and D: assessment of net benefits, ex ante expected as well as ex post realized; tailoring of R and D portfolios to policy goals; and guiding the contractual organization of R and D production. Additionally, evaluation of R and D and scientific activity tend to be distinctly retrospective, principally because of the long lags between the initial production activity and the observability of consequences. Extending the purview of economic evaluation of R and D, they find ample opportunity for evaluation that can inform current R and D management practice. The conduct of R and D is organized through a series of explicit and implicit contracts designed to elicit long-term commitments by some agents while attempting to limit the commitment by others. It is natural to consider the efficiency with which R and D is conducted as a subject for economic inquiry, although in practice such inquiries generally are restricted to accounting exercises. In evaluating the efficiency with which R and D is done, the current ordinary practice is to look at labor rates and equipment and materials prices while considering quantities of those items …
Date: October 19, 1998
Creator: Jones, D.W. & Paik, I.K.
Object Type: Article
System: The UNT Digital Library