Emergency Funding for Agriculture: A Brief History of Congressional Action, 1988-June 1999 (open access)

Emergency Funding for Agriculture: A Brief History of Congressional Action, 1988-June 1999

Between 1988 and June 1999, thirteen emergency supplemental or farm disaster acts provided a total of $17 billion in emergency funding for U.S. Department of Agriculture (USDA) programs. The vast majority of this amount has gone directly to farmers, primarily in the form of disaster payments ($12.2 billion) to any farmer suffering a significant crop loss caused by a natural disaster, and "market loss" payments ($3.1 billion) to help grain, cotton, and dairy farmers recover from low farm commodity prices. The remaining $1.7 billion has gone to a wide array of other USDA programs, including those for other forms of farm disaster assistance, farm loans, and overseas food aid. Congress is expected to consider a multi-billion financial assistance package for farmers sometime this year.
Date: July 19, 1999
Creator: Chite, Ralph M.
Object Type: Report
System: The UNT Digital Library
Housing Finance: Budget Savings From the Sale of HUD Loans (open access)

Housing Finance: Budget Savings From the Sale of HUD Loans

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO the reviewed the reasonableness of the: (1) Department of Housing and Urban Development's (HUD) estimates of budgetary savings from the sale of its single-family loans; and (2) model HUD used to estimate savings from the sale of multifamily loans."
Date: July 19, 1999
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
DOD Contract Management: Greater Attention Needed to Identify and Recover Overpayments (open access)

DOD Contract Management: Greater Attention Needed to Identify and Recover Overpayments

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO updated its previous report on the Department of Defense's (DOD) overpayments to contractors and subsequent refunds to the Defense Finance Accounting Service (DFAS), focusing on: (1) DOD's efforts to identify and recover overpayments made through fiscal year (FY) 1998; and (2) whether 13 contractors were retaining overpayments and how quickly overpayments were refunded."
Date: July 19, 1999
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
National Archives: Preserving Electronic Records in an Era of Rapidly Changing Technology (open access)

National Archives: Preserving Electronic Records in an Era of Rapidly Changing Technology

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO provided information on the preservation of electronic records, focusing on the: (1) challenges that confront the National Archives and Records Administration (NARA) and federal agencies as a result of their increased reliance on electronic media; (2) status of selected agencies' and NARA's implementation of electronic records management (ERM); and (3) ERM policies and procedures of selected other governments (state and foreign)."
Date: July 19, 1999
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
Intermetallic insertion anodes for lithium batteries. (open access)

Intermetallic insertion anodes for lithium batteries.

Intermetallic alloys have been investigated for many years as anode materials for lithium batteries and, more recently, as alternative electrodes to carbon, because of several intrinsic advantages including high capacity and safety. Some of the most studied alloys utilize tin as the active component because of its high theoretical capacity (996 mAh/g) and its slightly higher operating voltage (<400 mV) compared to metallic lithium. To date, the use of binary lithium alloys as anodes has been limited to the select number of main group elements (e.g. Sn) that can be lithiated at an appropriate voltage with acceptable kinetics. A major disadvantage of binary Li{sub x}M alloy systems is that major phase changes occur during the electrochemical cycling of lithium. Severe volume expansion and contraction of the metal matrix, which limit the cycle life of the lithium cell, normally accompany these phase changes. The. most successful approach to overcoming this limitation has been the use of intermetallic alloys MM{prime} consisting of two (or more) metals, at least one of which is an ''active'' alloying element (M) and the other an ''inactive'' (M{prime}) element. During the reaction with lithium, such a system breaks up into regions of Li{sub x}M and inactive M{prime}. …
Date: July 19, 1999
Creator: Johnson, C. S.; Kahaian, A. J.; Kepler, K. D.; Scott, M.; Thackerary, M. M. & Vaughey, J.
Object Type: Article
System: The UNT Digital Library
Lick sodium laser guide star: performance during the 1998 LGS observing campaign (open access)

Lick sodium laser guide star: performance during the 1998 LGS observing campaign

The performance of a sodium laser guide star adaptive optics system depends crucially on the characteristics of the laser guide star in the sodium layer. System performance is quite sensitive to sodium layer spot radiance, that is, return per unit sterradian on the sky, hence we have been working to improve projected beam quality via improvements to the laser and changes to the launched beam format. The laser amplifier was reconfigured to a ''bounce-beam'' geometry, which considerably improves wavefront quality and allows a larger round instead of square launch beam aperture. The smaller beacon makes it easier to block the unwanted Rayleigh light and improves the accuracy of Hartmann sensor wavefront measurements in the A0 system. We present measurements of the beam quality and of the resulting sodium beacon and compare to similar measurements from last year.
Date: July 19, 1999
Creator: Bauman, B; Friedman, H & Gavel, D T
Object Type: Article
System: The UNT Digital Library
Autonomous, agile micro-satellites and supporting technologies (open access)

Autonomous, agile micro-satellites and supporting technologies

This paper updates the on-going effort at Lawrence Livermore National Laboratory to develop autonomous, agile micro-satellites (MicroSats). The objective of this development effort is to develop MicroSats weighing only a few tens of kilograms, that are able to autonomously perform precision maneuvers and can be used telerobotically in a variety of mission modes. The required capabilities include satellite rendezvous, inspection, proximity-operations, docking, and servicing. The MicroSat carries an integrated proximity-operations sensor-suite incorporating advanced avionics. A new self-pressurizing propulsion system utilizing a miniaturized pump and non-toxic mono-propellant hydrogen peroxide was successfully tested. This system can provide a nominal 25 kg MicroSat with 200-300 m/s delta-v including a warm-gas attitude control system. The avionics is based on the latest PowerPC processor using a CompactPCI bus architecture, which is modular, high-performance and processor-independent. This leverages commercial-off-the-shelf (COTS) technologies and minimizes the effects of future changes in processors. The MicroSat software development environment uses the Vx-Works real-time operating system (RTOS) that provides a rapid development environment for integration of new software modules, allowing early integration and test. We will summarize results of recent integrated ground flight testing of our latest non-toxic pumped propulsion MicroSat testbed vehicle operated on our unique dynamic air-rail.
Date: July 19, 1999
Creator: Breitfeller, E; Dittman, M D; Gaughan, R J; Jones, M S; Kordas, J F; Ledebuhr, A G et al.
Object Type: Article
System: The UNT Digital Library
Sensitivity of natural gas HCCI combustion to fuel and operating parameters using detailed kinetic modeling (open access)

Sensitivity of natural gas HCCI combustion to fuel and operating parameters using detailed kinetic modeling

This paper uses the HCT (Hydrodynamics, Chemistry and Transport) chemical kinetics code to analyze natural gas HCCI combustion in an engine. The HCT code has been modified to better represent the conditions existing inside an engine, including a wall heat transfer correlation. Combustion control and low power output per displacement remain as two of the biggest challenges to obtaining satisfactory performance out of an HCCI engine, and these are addressed in this paper. The paper considers the effect of natural gas composition on HCCI combustion, and then explores three control strategies for HCCI engines: DME (dimethyl ether) addition, intake heating and hot EGR addition. The results show that HCCI combustion is sensitive to natural gas composition, and an active control may be required to compensate for possible changes in composition. The three control strategies being considered have a significant effect in changing the combustion parameters for the engine, and should be able to control HCCI combustion.
Date: July 19, 1999
Creator: Aceves, S.; Dibble, R.; Flowers, D.; Smith, J. R. & Westbrook, C. K.
Object Type: Article
System: The UNT Digital Library
Surface and interface modification science and technology. (open access)

Surface and interface modification science and technology.

Surface modification of solids is of scientific and technological interest due to its significant benefits in a wide variety of applications. Various coatings applications such as corrosion protection and electrical insulators and conductors are required for proper engineering design based on geometrical relationships between interfaces and on thermodynamic/kinetic considerations for the development of surface modifications. This paper will explore three basic examples: the proton conductor BaCeO{sub 3}, high-temperature protective coatings, and epitaxial relationships between interfaces.
Date: July 19, 1999
Creator: Park, J.-H.
Object Type: Article
System: The UNT Digital Library
Electrochemical studies of Mg-doped Li{sub 4}Ti{sub 5}O{sub 12} anodes. (open access)

Electrochemical studies of Mg-doped Li{sub 4}Ti{sub 5}O{sub 12} anodes.

Commercial lithium-ion batteries use carbon as the material of choice for the anode. However, because lithiated carbon has a voltage very close to the potential of metallic lithium, there are concerns about the safety of fully-charged carbon electrodes. The safety issue can be addressed by using a material that intercalates lithium at a higher voltage. A promising material is the lithium-titanium-oxide spinel material Li{sub 4}Ti{sub 5}O{sub 12} which can accommodate 3 Li{sup +} ions per formula unit (corresponding to 175 mAh/g) in a two-phase reaction at approximately 1.5 V versus lithium. One of the drawbacks of this system is that the end-member Li{sub 4}Ti{sub 5}O{sub 12} is electronically insulating, which limits electron transfer at the electrode surface. By doping this material with magnesium, Li{sub 4{minus}x}Mg{sub x}Ti{sub 5}O{sub 12}, we introduced mixed-valent Ti{sup 4+}/Ti{sup 3+} into the stoichiometric spinel structure and thereby increased the electronic conductivity by several orders of magnitude without sacrificing electrochemical performance. In this presentation we will provide data on the extent of the solid solution in Li{sub 4{minus}x}Mg{sub x}Ti{sub 5}O{sub 12}, the variation of electronic conductivity as a function of dopant concentration and the rate capability of the doped material.
Date: July 19, 1999
Creator: Chen, C. H.; Jansen, A. N. & Vaughey, J.
Object Type: Article
System: The UNT Digital Library
Analysis and Tests of Pultruded Blades for Wind Turbine Rotors (open access)

Analysis and Tests of Pultruded Blades for Wind Turbine Rotors

PS Enterprises, Inc. investigated a flexible, downwind, free-yaw, five-blade rotor system employing pultruded blades. A rotor was designed, manufactured and tested in the field. A preliminary design study and proof of concept test were conducted to assess the feasibility of using pultruded blades for wind turbine rotors. A 400 kW turbine was selected for the design study and a scaled 80 kW rotor was fabricated and field tested as a demonstration of the concept. The design studies continued to support the premise that pultruded blades offer the potential for significant reductions in rotor weight and cost. The field test provided experimental performance and loads data that compared well with predictions using the FLEXDYNE aeroelastic analysis. The field test also demonstrated stable yaw behavior and the absence of stall flutter over the wind conditions tested. During the final year of the contract, several studies were conducted by a number of independent consultants to address specific technical issues related to pultruded blades that could impact the commercial viability of turbines using this technology. The issues included performance, tower strikes, yaw stability, stall flutter, fatigue, and costs. While the performance of straight pultruded blades was projected to suffer a penalty of about 13% …
Date: July 19, 1999
Creator: Cheney, M. C. (PS Enterprises, Glastonbury, Connecticut); Olsen, T.; Quandt, G. & Archidiacono, P.
Object Type: Report
System: The UNT Digital Library
Tests of Low Scale Quantum Gravity in e{sup -}e{sup -} and {gamma}{gamma} Collisions (open access)

Tests of Low Scale Quantum Gravity in e{sup -}e{sup -} and {gamma}{gamma} Collisions

Arkani-Hamed, Dimopoulos and Dvali have recently proposed that gravity may become strong at energies near 1 TeV due to the existence of large extra dimensions thus ''removing'' the hierarchy problem. In this talk we examine the exchange of towers of Kaluza-Klein gravitons and their influence on Moller scattering as well as the production of pairs of massive gauge bosons in {gamma}{gamma}collisions. These tower exchanges lead to a set of new dimension-8 operators that can significantly alter the Standard Model expectations for these processes. In the case of {gamma}{gamma}collisions, the role of polarization for both the initial state photons and the final state gauge bosons in improving sensitivity to graviton exchange is emphasized.
Date: July 19, 1999
Creator: Rizzo, Thomas G.
Object Type: Report
System: The UNT Digital Library
Subpicosecond single-shot waveform measurement using temporal imaging (open access)

Subpicosecond single-shot waveform measurement using temporal imaging

Experimental results from a new single-transient optical recorder with < 300 fs resolution are presented. The system uses a 103x temporal imaging system to expand the waveform which is then recorded with a streak camera.
Date: July 19, 1999
Creator: Bennett, C V & Kolner, B H
Object Type: Article
System: The UNT Digital Library
Hybrid options for light-duty vehicles. (open access)

Hybrid options for light-duty vehicles.

Hybrid electric vehicles (HEVs) offer great promise in improving fuel economy. In this paper, we analyze why, how, and by how much vehicle hybridization can reduce energy consumption and improve fuel economy. Our analysis focuses on efficiency gains associated solely with vehicle hybridization. We do not consider such other measures as vehicle weight reduction or air- and tire-resistance reduction, because such measures would also benefit conventional technology vehicles. The analysis starts with understanding the energy inefficiencies of light-duty vehicles associated with different operation modes in US and Japanese urban and highway driving cycles, with the corresponding energy-saving potentials. The potential for fuel economy gains due to vehicle hybridization can be estimated almost exclusively on the basis of three elements: the reducibility of engine idling operation, the recoverability of braking energy losses, and the capability of improving engine load profiles to gain efficiency associated with specific HEV configurations and control strategies. Specifically, we evaluate the energy efficiencies and fuel economies of a baseline MY97 Corolla-like conventional vehicle (CV), a hypothetical Corolla-based minimal hybrid vehicle (MHV), and a MY98 Prius-like full hybrid vehicle (FHV). We then estimate energy benefits of both MHVs and FHVs over CVs on a performance-equivalent basis. We conclude …
Date: July 19, 1999
Creator: An, Feng; Stodolsky, Frank & Santini, Danilo
Object Type: Article
System: The UNT Digital Library
CHARACTERIZATION OF THE NEW NSLS INFARED MICROSPECTROSCOPY BEAMLINE U10B. (open access)

CHARACTERIZATION OF THE NEW NSLS INFARED MICROSPECTROSCOPY BEAMLINE U10B.

The first of several new infrared beamlines, built on a modified bending magnet port of the NSLS VUV ring, is now operational for mid-infrared microspectroscopy. The port simultaneously delivers 40 mrad by 40 mrad to two separate beamlines and spectrometer endstations designated U10A and U10B. The latter is equipped with a scanning infrared microspectrometer. The combination of this instrument and high brightness synchrotron radiation makes diffraction-limited microspectroscopy practical. This paper describes the beamline's performance and presents quantitative information on the diffraction-limited resolution.
Date: July 19, 1999
Creator: CARR,G.L.
Object Type: Article
System: The UNT Digital Library
TIME-RESOLVED INFRARED SPECTROSCOPY IN THE U121R BEAMLINE AT THE NSLS (open access)

TIME-RESOLVED INFRARED SPECTROSCOPY IN THE U121R BEAMLINE AT THE NSLS

A facility for performing time-resolved infrared spectroscopy has been developed at the NSLS, primarily at beamline U12IR. The pulsed IR light from the synchrotron is used to perform pump-probe spectroscopy. The authors present here a description of the facility and results for the relaxation of photoexcitations in both a semiconductor and superconductor.
Date: July 19, 1999
Creator: Carr, G. L.; Laveigne, J. D.; Lobo, R. P. S. M.; Reitze, D. H. & Tanner, D. B.
Object Type: Article
System: The UNT Digital Library
Evidence for millimeter-wave coherent emission from the NSLS VUV ring (open access)

Evidence for millimeter-wave coherent emission from the NSLS VUV ring

Coherent synchrotron radiation from the NSLS VUV ring has been detected and partially characterized. The observations have been performed at the new far infrared beamline U12IR. The coherent radiation is peaked near a wavelength of 7mm and occurs in short duration bursts. The bursts occur only when the electron beam current (I) exceeds a threshold value (I{sub th}), which itself varies with ring operating conditions. Beyond threshold, the average intensity of the emission is found to increase as (I-I{sub th}). The coherent emission implies micro-bunching of the electron beam due to a longitudinal instability.
Date: July 19, 1999
Creator: Carr, G.L.
Object Type: Article
System: The UNT Digital Library
Correlation between nuclear response and defects in CZT (open access)

Correlation between nuclear response and defects in CZT

Vertical high pressure Bridgman (VHPB) was considered until now to be the most successful crystal growth method to produce Cd{sub 1{minus}x}Zn{sub x}Te (CZT), (0.04 < x < 0.24), for X- and gamma-ray detector crystals. Recently Horizontal Bridgman (HB) Cd{sub 1{minus}x}Zn{sub x}Te crystals produced by IMARAD Co. have also been successfully fabricated into nuclear spectroscopic radiation detectors. In view of the database of many years' study of the electrical properties of VHPB CZT grown and obtained from various sources, the authors also studied the HB CZT crystals in order to compare the defects present in both different kinds of crystals grown by different methods. The VHB-grown samples were examined using thermoelectric emission spectroscopy (TEES), X- and gamma ray spectroscopy and laser induced transient charge technique (TCT). The surface and the bulk crystalline homogeneity were mapped using triaxial double crystal x-ray diffraction (TADXRD) and infrared transmission spectroscopy (IR). They have found a correlation between crystallinity, IR transmission microstructure and trapping times. Spectrometer grade VHPB CZT crystals exhibit trapping times of 20 {micro}s for electrons and 7 {micro}s for holes, however, regions, which were opaque to IR transmission, had trapping times shorter by one order of magnitude. The trapping times of HB CZT …
Date: July 19, 1999
Creator: Hermon, H.; Schieber, M.; James, R. B.; Lee, E.; Cross, E.; Goorsky, M. et al.
Object Type: Article
System: The UNT Digital Library
Characterization of the new NSLS infrared microspectroscopy beamline U10B (open access)

Characterization of the new NSLS infrared microspectroscopy beamline U10B

The first of several new infrared beamlines, built on a modified bending magnet port of the NSLS VUV ring, is now operational for mid-infrared microspectroscopy. The port simultaneously delivers 40 mrad by 40 mrad to two separate beamlines and spectrometer endstations designated U10A and U10B. The latter is equipped with a scanning infrared microspectrometer. The combination of this instrument and high brightness synchrotron radiation makes diffraction-limited microspectroscopy practical. This paper describes the beamline's performance and presents quantitative information on the diffraction-limited resolution.
Date: July 19, 1999
Creator: Carr, G.L.
Object Type: Article
System: The UNT Digital Library
EVIDENCE FOR MILLIMETER-WAVE COHERENT EMISSION FROM THE NSLS VUV RING. (open access)

EVIDENCE FOR MILLIMETER-WAVE COHERENT EMISSION FROM THE NSLS VUV RING.

Coherent synchrotron radiation from the NSLS VUV ring has been detected and partially characterized. The observations have been performed at the new far infrared beamline U12IR. The coherent radiation is peaked near a wavelength of 7mm and occurs in short duration bursts. The bursts occur only when the electron beam current (I) exceeds a threshold value (I{sub th}), which itself varies with ring operating conditions. Beyond threshold, the average intensity of the emission is found to increase as (I-I{sub th}). The coherent emission implies micro-bunching of the electron beam due to a longitudinal instability.
Date: July 19, 1999
Creator: CARR,G.L.
Object Type: Article
System: The UNT Digital Library
SYNTHESIS OF METHYL METHACRYLATE FROM COAL-DERIVED SYNGAS (open access)

SYNTHESIS OF METHYL METHACRYLATE FROM COAL-DERIVED SYNGAS

Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. The research team has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, we are currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. During the April-June quarter(04-06/99) the first in-situ formaldehyde generation from DME and condensation with methyl propionate is demonstrated and the results are summarized. The supported niobium catalyst shows better condensation activity, but supported tungsten catalyst has higher formaldehyde selectivity. The project team has also completed a 200-hour long term test of PA-HCHO condensation over 30% Nb{sub 2}O{sub 5}/SiO{sub 2}. Three activity cycles and two regeneration cycles were carried out. 30% Nb{sub 2}O{sub 5}/SiO{sub 2} showed similar MAA yields as 10% Nb{sub 2}O{sub 5}/SiO{sub 2} at 300 C. However, the deactivation appears to be slower with …
Date: July 19, 1999
Creator: Gogate, Makarand R.; Spivey, James J.; Zoeller, Joseph R.; Colberg, Richard D. & Choi, Gerald N.
Object Type: Report
System: The UNT Digital Library
Flow Visualization and Measurements of the Mixing Evolution of a Shock-Accelerated Gas Curtain (open access)

Flow Visualization and Measurements of the Mixing Evolution of a Shock-Accelerated Gas Curtain

We describe a highly-detailed experimental characterization of the impulsively driven Rayleigh-Taylor instability, called the Richtmyer-Meshkov instability. This instability is produced by flowing a diffuse, vertical curtain of heavy gas (SF{sub 6}) into the test section of an air-filled horizontally oriented shock tube. The instability evolves after the passage of a Mach 1.2 shock past the curtain, and the development of the curtain is visualized by seeding the SF{sub 6} with small (d{approximately}0.5 and micro;m) glycol droplets using a modified theatrical fog generator. Because the event lasts only 1 ms and the initial conditions vary from test to test, rapid and complete data acquisition is required in order to characterize the initial and dynamic conditions for each experimental shot. Through the use of a custom-built pulsed Nd: YAG laser, we are able to image the flowfield at seven different times. We acquire a double-pulsed image of the flow with the use of a second pulsed Nd:YAG, which is used to determine the instantaneous velocity field using Particle Image Velocimetry (PIV). During a single experiment, high resolution images of the initial conditions and dynamic conditions are acquired using three CCD cameras. Issues of the fidelity of the flow seeding technique and the …
Date: July 19, 1999
Creator: Prestridge, K.; Vorobieff, P.V.; Rightley, P.M. & Benjamin, R.F
Object Type: Article
System: The UNT Digital Library
Two-Color Experiments Combining the UV-Storage Ring Free Electron Laser and SA5 IR Beamline at Super-ACO (open access)

Two-Color Experiments Combining the UV-Storage Ring Free Electron Laser and SA5 IR Beamline at Super-ACO

This article reviews pump-probe experiments with a storage ring based free-electron laser pump, and synchrotron radiation as a broadband spectroscopic probe.
Date: July 19, 1999
Creator: Nahon, Laurent; Renault, Eric; Couprie, Marie-Emmanuelle; Nutarelli, Daniele; Garzella, David; Billardon, Michel et al.
Object Type: Article
System: The UNT Digital Library
NCPV FY 1998 Annual Report (open access)

NCPV FY 1998 Annual Report

This report summarizes the in-house and subcontracted research and development (R and D) activities under the National Center for Photovoltaics (NCPV) from October 1, 1997 through September 30, 1998 (FY 1998). The NCPV is part of the U.S. Department of Energy's (DOE's) National Photovoltaics Program, as described in the DOE National Photovoltaics Program Plan for 1996-2000. The mission of the DOE National Photovoltaics Program is to make PV a significant part of the domestic economy--as an industry and as an energy resource. The two primary goals of the national program are to (1) maintain the U.S. industry's world leadership in research and technology development and (2) help the U.S. industry remain a major, profitable force in the world market. The NCPV provides leadership and support to the national program toward achieving its mission and goals.
Date: July 19, 1999
Creator: McConnell, R. D. & Hansen, A.
Object Type: Book
System: The UNT Digital Library