States

Managing For Results: Assessing the Quality of Program Performance Data (open access)

Managing For Results: Assessing the Quality of Program Performance Data

Correspondence issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO provided information on how federal agencies should assess the quality of program performance data."
Date: May 25, 2000
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
Federally Chartered Corporation: Review of the Financial Statement Audit Report for the Jewish War Veterans, U.S.A., National Memorial, Incorporated, for Fiscal Year 1999 (open access)

Federally Chartered Corporation: Review of the Financial Statement Audit Report for the Jewish War Veterans, U.S.A., National Memorial, Incorporated, for Fiscal Year 1999

Correspondence issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO reviewed the financial statement audit report for the Jewish War Veterans, U.S.A., National Memorial, Incorporated, focusing on whether the audit report complied with the financial reporting requirements of the law."
Date: August 25, 2000
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
GAO Report on Applying Agreed-Upon Procedures: Airport and Airway Trust Fund Excise Taxes (open access)

GAO Report on Applying Agreed-Upon Procedures: Airport and Airway Trust Fund Excise Taxes

Correspondence issued by the General Accounting Office with an abstract that begins "Pursuant to a legislative requirement, GAO provided information on: (1) whether the excise tax revenue distributed to the Airport and Airway Trust Fund (AATF) for the fiscal year (FY) ended September 30, 1999, is supported by the underlying records; and (2) FY 1999 AATF activity."
Date: February 25, 2000
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
Federally Chartered Corporation: Review of the Financial Statement Audit Report for the Legion of Valor of the United States of America, Incorporated, for Fiscal Year 1999 (open access)

Federally Chartered Corporation: Review of the Financial Statement Audit Report for the Legion of Valor of the United States of America, Incorporated, for Fiscal Year 1999

Correspondence issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO reviewed the audit report for the Legion of Valor of the United States of America, Incorporated, for the fiscal year ended April 30, 1999, focusing on whether the audit report complied with the financial reporting requirements of the law."
Date: August 25, 2000
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
{sup 203,205}Tl NMR Studies of Crystallographically Characterized Thallium Alkoxides. X-Ray Structures of [Tl(OCH{sub 2}CH{sub 3})]4 and [Tl(OAr)]{sub infinity} where OAr = OC{sub 6}H{sub 3}(Me){sub 2}-2,6 and OC{sub 6}H{sub 3}(Pr{sup i}){sub 2}-2,6 (open access)

{sup 203,205}Tl NMR Studies of Crystallographically Characterized Thallium Alkoxides. X-Ray Structures of [Tl(OCH{sub 2}CH{sub 3})]4 and [Tl(OAr)]{sub infinity} where OAr = OC{sub 6}H{sub 3}(Me){sub 2}-2,6 and OC{sub 6}H{sub 3}(Pr{sup i}){sub 2}-2,6

[Tl(OCH{sub 2}CH{sub 3})]{sub 4}, (1) was reacted with excess HOR to prepare a series of [Tl(OR)]{sub n} where OR= OCHMe{sub 2} (2, n = 4), OCMe{sub 3} (3, n = 4), OCH{sub 2}CMe{sub 3} (4, n = 4), OC{sub 6}H{sub 3}(Me){sub 2}-2,6 (5, n = {infinity}), and OC{sub 6}H{sub 3}(Pr{sup i}){sub 2}-2,6 (6, n = {infinity}). Single crystal X-ray diffraction was used to determine the structure of compounds ligated by more sterically demanding ligands. Compound 4 was found to adopt a cubane structure, while 5 and 6 formed linear polymeric structures. These compounds were additionally characterized by {sup 203,205}Tl solution and {sup 205}Tl solid state NMR. Compounds 1--4 were found to remain intact in solution while the polymeric species, 5 and 6, appeared to be fluxional. While variations in the solution and solid state structures for the tetrameric [Tl(OR)]{sub 4} and polymeric [Tl(OAr)]{sub {infinity}} may be influenced by the steric hindrance of their respective ligands, the covalency of the species is believed to be more an effect of the parent alcohol acidity.
Date: July 25, 2000
Creator: Zechmann, Cecilia A.; Boyle, Timothy J.; Pedrotty, Dawn M.; Alam, Todd M.; Lang, David P. & Scott, Brain L.
Object Type: Article
System: The UNT Digital Library
Making connections: Case studies of interconnection barriers and their impact on distributed power projects (open access)

Making connections: Case studies of interconnection barriers and their impact on distributed power projects

Distributed power is modular electric generation or storage located close to the point of use. Based on interviews of distributed generation project proponents, this report reviews the barriers that distributed generators of electricity are encountering when attempting to interconnect to the electrical grid. Descriptions of 26 of 65 case studies are included in the report. The survey found and the report describes a wide range of technical, business-practice, and regulatory barriers to interconnection. An action plan for reducing the impact of these barriers is also included.
Date: July 25, 2000
Creator: Alderfer, B.; Eldridge, M. & Starrs, T.
Object Type: Report
System: The UNT Digital Library
Large-scale structure from quantum fluctuations in the early universe (open access)

Large-scale structure from quantum fluctuations in the early universe

A better understanding of the formation of large-scale structure in the Universe is arguably the most pressing question in cosmology. The most compelling and promising theoretical paradigm, Inflation + Cold Dark Matter, holds that the density inhomogeneities that seeded the formation of structure in the Universe originated from quantum fluctuations arising during inflation and that the bulk of the dark matter exists as slowing moving elementary particles (cold dark matter) left over from the earliest, fiery moments. Large redshift surveys (such as the SDSS and 2dF) and high-resolution measurements of CBR anisotropy (to be made by the MAP and Planck Surveyor satellites) have the potential to decisively test Inflation + Cold Dark Matter and to open a window to the very early Universe and fundamental physics.
Date: May 25, 2000
Creator: Turner, Michael
Object Type: Article
System: The UNT Digital Library
Ceramicrete: A novel ceramic packaging system for spent-fuel transport and storage (open access)

Ceramicrete: A novel ceramic packaging system for spent-fuel transport and storage

This presentation summarizes efforts to develop and apply chemically bonded phosphate ceramic (Ceramicrete{trademark}) technology for radiation shielding applications. The specific application being targeted is a packaging system for spent-fuel transport and storage. Using Ceramicrete technology under ambient conditions, the authors can produce dense and hard ceramic forms that incorporate second-phase material. Ceramicrete inherently is a superior shielding material because it contains large amounts of bound water in its crystal structure and can be cast in any shape. A parametric study was conducted on Ceramicrete that contained second-phase additions of metals and other ceramic powders. Results of various standardized tests that included mechanical performance and shielding from neutrons are presented. The fabrication of complex shapes and structures by Ceramicrete technology is discussed. Ceramicrete is compared with other currently available shielding systems that are based on concrete and polymers.
Date: February 25, 2000
Creator: Singh, D.; Jeong, S. Y.; Dwyer, K. & Abesadze, T.
Object Type: Article
System: The UNT Digital Library
Composition and property measurements for PHA Phase 2 glasses (open access)

Composition and property measurements for PHA Phase 2 glasses

The results presented in this report are for six Phase 2 Precipitate Hydrolysis Aqueous (PHA) glasses, each of which was targeted to contain 30 wt percent simulated PUREX sludge on a glass basis.
Date: January 25, 2000
Creator: Edwards, T. B.
Object Type: Report
System: The UNT Digital Library
A simple extension of two-phase characteristic curves to include the dry region (open access)

A simple extension of two-phase characteristic curves to include the dry region

Two-phase characteristic curves are necessary for the simulation of water and vapor flow in porous media. Existing functions such as van Genuchten, Brooks and Corey, and Luckner et al. have significant limitations in the dry region as the liquid saturation goes to zero. This region, which is important in a number of applications including liquid and vapor flow and vapor-solid sorption, has been the subject of a number of previous investigations. Most previous studies extended standard capillary pressure curves into the adsorption region to zero water content and required a refitting of the revised curves to the data. In contrast, the present method provides for a simple extension of existing capillary pressure curves without the need to refit the experimental data. Therefore, previous curve fits can be used, and the transition between the existing fit and the relationship in the adsorption region is easily calculated. The data-model comparison shows good agreement. This extension is a simple and convenient way to extend existing curves to the dry region.
Date: January 25, 2000
Creator: WEBB,STEPHEN W.
Object Type: Article
System: The UNT Digital Library
Proceedings of the 1999 Photovoltaic Performance and Reliability Workshop (open access)

Proceedings of the 1999 Photovoltaic Performance and Reliability Workshop

This report compiles the presentations made at the 1999 Photovoltaic Performance and Reliability Workshop, held on October 18-21, 1999, in Vail, Colorado. The theme of the workshop was ''Setting a Standard for PV Performance and Reliability,'' with the focus on testing, test methods, evaluation, and standards. The workshop provided a venue for technical discussions on four topical areas: module rating, module qualification, power processing, and systems. Includes the following. (1) Module Performance Rating. IEEE PAR 1479 ''Draft Recommended Practice for the Evaluation of Photovoltaic Module Energy Production'' - proceed with validating the models and inputs; look closely at the need to develop a similar activity for system energy rating. (2) Module Qualification Testing. IEEE Std.1262 ''Recommended Practice for Qualification of PV Modules'' - continue validation of proposed new qualification tests at NREL, ISPRA, and US PV industry and test lab facilities. Reliability testing should be done and should include module qualification. (3) Power Processing. The most pressing concerns expressed by individuals included system design and system components integration aspects; reliability assurance; interconnection and the need for a uniform, national approach; testing; and, infrastructure development. (4) Systems Evaluation. The most pressing concerns reiterated the concerns in the power processing session. IEEE …
Date: January 25, 2000
Creator: Basso, T. S.
Object Type: Article
System: The UNT Digital Library
Thermal evaluation and performance of high-power Lithium-ion cells (open access)

Thermal evaluation and performance of high-power Lithium-ion cells

Under the sponsorship of the US Advanced Battery Consortium (USABC) and the Partnership for a New Generation of Vehicles (PNGV), Saft has developed high-power lithium-ion (Li-Ion) batteries for hybrid electric vehicles (HEVs). These high-power Li-Ion batteries are being evaluated for the US Department of Energy's (DOE) Hybrid Vehicle Propulsion Program. As part of this program, the National Renewable Energy Laboratory (NREL) characterized the thermal performance of the Saft (6-Ah) Li-Ion cells. The characterization included (1) obtaining thermal images of cells under a specified cycle, (2) measuring heat generation from the cells at various temperatures and under various charge/discharge profiles, and (3) determining the cells' capabilities for following a simulated power profile (driving cycle) at various initial states of charge and temperatures.
Date: January 25, 2000
Creator: Keyser, M.; Pesaran, A.; Oweis, S.; Chagnon, G. & Ashtiani, C.
Object Type: Article
System: The UNT Digital Library
Continuum-based FEM modeling of ceramic powder compaction using a cap-plasticity constitutive model (open access)

Continuum-based FEM modeling of ceramic powder compaction using a cap-plasticity constitutive model

Common ceramic component manufacturing typically involves the processing of the raw materials in powder form. Granulated powder is formed into a green body of the desired size and shape by consolidation, often by simply pressing nominally dry powder. Ceramic powders are commonly pressed in steel dies or rubber bags with the aim of producing a near-net-shape green body for subsequent sintering. Density gradients in these compacts, introduced during the pressing operation, are often severe enough to cause distortions in the shape of the part during sintering due to nonuniform shrinkage. In such cases, green machining or diamond grinding operations may be needed to obtain the desired final shape and size part. In severe cases, nonuniform shrinkage may even cause fracture in the parts during sintering. Likewise, density gradients can result in green bodies that break during ejection from the die or that are too fragile to be handled during subsequent processing. Empirical relationships currently exist to describe powder compaction but provide little understanding of how to control die design or compaction parameters to minimize density gradients thereby forcing the designer to use expensive and time consuming trial and error procedures. For this reason, interest has grown in developing computational tools …
Date: January 25, 2000
Creator: Arguello, Jose G., Jr.; Fossum, Arlo F.; Zeuch, David H. & Ewsuk, Kevin G.
Object Type: Article
System: The UNT Digital Library
A high-charge high-brightness L-band photocathode RF gun (open access)

A high-charge high-brightness L-band photocathode RF gun

The Argonne Wakefield Accelerator has been successfully commissioned and used for conducting wakefield experiments in dielectric loaded structures and plasmas. Although the initial wakefield experiments were successful, higher drive beam quality would substantially improve the wakefield accelerating gradients. In this paper the authors present a new 1-1/2 cell L-band photocathode RF gun design. This gun will produce 10--100 nC beam with 2--5 ps ms pulse length and normalized emittance less than 100 mm mrad. The final gun design and numerical simulations of the beam dynamics are presented.
Date: February 25, 2000
Creator: Conde, M. E.; Gai, W.; Konecny, R.; Power, J. G.; Schoessow, P. & Sun, X.
Object Type: Article
System: The UNT Digital Library
Characterization and decant of Tank 42H sludge sample ESP-200 (open access)

Characterization and decant of Tank 42H sludge sample ESP-200

DWPF Engineering requested that the Savannah River Technology Center (SRTC) provide a demonstration of the DWPF flowsheet on sludge from Tank 42H in the Shielded Cell facility. A 5 liter sample of the Tank 42H sludge (ESP-200), obtained with the tank contents fully mixed, arrived at SRTC on January 20, 1998. This report details receipt of the 5 liter sample at SRTC, the decant of the sample, and the characterization of the pre- and post-decant Tank 42H sludge. Evaluation of the measured composition of the supernate indicates Sample ESP-200 became diluted approximately 20 percent by volume prior to receipt. This dilution complicates the relationship of the characterization of Post-Decant ESP-200 to the current contents of Tank 42H. For the purposes of modeling the current tank contents of Tank 42H, this report provides an estimated composition based on analytical data of recent samples from Tank 42H.
Date: April 25, 2000
Creator: Hay, M.S.
Object Type: Report
System: The UNT Digital Library
Corrosion detection in multi-layered rotocraft structures (open access)

Corrosion detection in multi-layered rotocraft structures

Rotorcraft structures do not readily lend themselves to quantifiable inspection methods due to airframe construction techniques. Periodic visual inspections are a common practice for detecting corrosion. Unfortunately, when the telltale signs of corrosion appear visually, extensive repair or refurbishment is required. There is a need to nondestructively evaluate airframe structures in order to recognize and quantify corrosion before visual indications are present. Nondestructive evaluations of rotorcraft airframes face inherent problems different from those of the fixed wing industry. Most rotorcraft lap joints are very narrow, contain raised fastener heads, may possess distortion, and consist of thinner gage materials ({approximately}0.012--0.125 inches). In addition the structures involve stack-ups of two and three layers of thin gage skins that are separated by sealant of varying thickness. Industry lacks the necessary data techniques, and experience to adequately perform routine corrosion inspection of rotorcraft. In order to address these problems, a program is currently underway to validate the use of eddy current inspection on specific rotorcraft lap joints. Probability of detection (POD) specimens have been produced that simulate two lap joint configurations on a model TH-57/206 helicopter. The FAA's Airworthiness Assurance Center (AANC) at Sandia Labs and Bell Helicopter have applied single and dual frequency …
Date: April 25, 2000
Creator: ROACH,DENNIS P.; WALKINGTON,PHILLIP D.; HOHMAN,ED & MARSHALL,GREG
Object Type: Article
System: The UNT Digital Library
Preliminary analysis of Block Island Power Company's use of clean distributed resources to provide power to its customers (open access)

Preliminary analysis of Block Island Power Company's use of clean distributed resources to provide power to its customers

This report is an analysis of the potential for Block Island Power Company (BIPCO) to use renewable energy and clean distributed resources to supply power to its customers. The preliminary conclusion of this work is that a system composed of clean distributed resources has the potential to be a technically and economically feasible alternative for BIPCO.
Date: January 25, 2000
Creator: Hoff, T. E.
Object Type: Report
System: The UNT Digital Library
Modeling of transient ionizing radiation effects in bipolar devices at high dose-rates (open access)

Modeling of transient ionizing radiation effects in bipolar devices at high dose-rates

To optimally design circuits for operation at high intensities of ionizing radiation, and to accurately predict their a behavior under radiation, precise device models are needed that include both stationary and dynamic effects of such radiation. Depending on the type and intensity of the ionizing radiation, different degradation mechanisms, such as photoelectric effect, total dose effect, or single even upset might be dominant. In this paper, the authors consider the photoelectric effect associated with the generation of electron-hole pairs in the semiconductor. The effects of low radiation intensity on p-II diodes and bipolar junction transistors (BJTs) were described by low-injection theory in the classical paper by Wirth and Rogers. However, in BJTs compatible with modem integrated circuit technology, high-resistivity regions are often used to enhance device performance, either as a substrate or as an epitaxial layer such as the low-doped n-type collector region of the device. Using low-injection theory, the transient response of epitaxial BJTs was discussed by Florian et al., who mainly concentrated on the effects of the Hi-Lo (high doping - low doping) epilayer/substrate junction of the collector, and on geometrical effects of realistic devices. For devices with highly resistive regions, the assumption of low-level injection is often …
Date: April 25, 2000
Creator: Fjeldly, T. A.; Deng, Y.; Shur, M. S.; Hjalmarson, Harold P. & Muyshondt, Arnoldo
Object Type: Article
System: The UNT Digital Library
An overview of the Nuclear Materials Focus Area research program (open access)

An overview of the Nuclear Materials Focus Area research program

The Nuclear Material Focus Area (NMFA) is responsible for providing comprehensive needs identification, integration of technology research and development activities, and technology deployment for stabilization, packaging, and interim storage of surplus nuclear materials within the DOE complex. The NMFA was chartered in April 1999 by the Office of Science and Technology (OST), an organizational component of the US Department of Energy's (DOE) Office of Environmental Management (EM). OST manages a national program to conduct basic and applied research, and technology development, demonstration, and deployment assistance that is essential to completing a timely and cost-effective cleanup of the DOE nuclear weapons complex. DOE/EM provides environmental research results, as well as cleanup technologies and systems, to meet high-priority end-user needs, reduce EM's major cost centers and technological risks, and accelerate technology deployments. The NMFA represents the segment of EM that focuses on technological solutions for re-using, transforming, and disposing excess nuclear materials and is jointly managed by the DOE Albuquerque Operations Office and the DOE Idaho Operations Office.
Date: February 25, 2000
Creator: Roberson, Gary D.; Polansky, Gary F.; Osborne, Ken K. & Randall, Virginia
Object Type: Article
System: The UNT Digital Library
Atom trap trace analysis (open access)

Atom trap trace analysis

A new method of ultrasensitive trace-isotope analysis has been developed based upon the technique of laser manipulation of neutral atoms. It has been used to count individual {sup 85}Kr and {sup 81}Kr atoms present in a natural krypton sample with isotopic abundances in the range of 10{sup {minus}11} and 10{sup {minus}13}, respectively. The atom counts are free of contamination from other isotopes, elements,or molecules. The method is applicable to other trace-isotopes that can be efficiently captured with a magneto-optical trap, and has a broad range of potential applications.
Date: May 25, 2000
Creator: Lu, Z. T.; Bailey, K.; Chen, C. Y.; Du, X.; Li, Y. M.; O'Connor, T. P. et al.
Object Type: Article
System: The UNT Digital Library
Crystal diffraction lens for medical imaging (open access)

Crystal diffraction lens for medical imaging

A crystal diffraction lens for focusing energetic gamma rays has been developed at Argonne National Laboratory for use in medical imaging of radioactivity in the human body. A common method for locating possible cancerous growths in the body is to inject radioactivity into the blood stream of the patient and then look for any concentration of radioactivity that could be associated with the fast growing cancer cells. Often there are borderline indications of possible cancers that could be due to statistical functions in the measured counting rates. In order to determine if these indications are false or real, one must resort to surgical means and take tissue samples in the suspect area. They are developing a system of crystal diffraction lenses that will be incorporated into a 3-D imaging system with better sensitivity (factors of 10 to 100) and better spatial resolution (a few mm in both vertical and horizontal directions) than most systems presently in use. The use of this new imaging system will allow one to eliminate 90% of the false indications and both locate and determine the size of the cancer with mm precision. The lens consists of 900 single crystals of copper, 4 mm x 4 …
Date: February 25, 2000
Creator: Smither, R. K. & Roa, D. E.
Object Type: Article
System: The UNT Digital Library
Working with arrays of inexpensive EIDE disk drives (open access)

Working with arrays of inexpensive EIDE disk drives

In today's marketplace, the cost per Terabyte of disks with EIDE interfaces is about a third that of disks with SCSI. Hence, three times as many particle physics events could be put online with EIDE. The modern EIDE interface includes many of the performance features that appeared earlier in SCSI. EIDE bus speeds approach 33 Megabytes/s and need only be shared between two disks rather than seven disks. The interal I/O rate of very fast (and expensive) SCSI disks is only 50% greater than EIDE disks. Hence, two EIDE disks whose combined cost is much less than one very fast SCSI disk can actually give more data throughput due to the advantage of multiple spindles and head actuators. The authors explore the use of 12 and 16 Gigabyte EIDE disks with motherboard and PCI bus card interfaces on a number of operating systems and CPUs. These include Red Hat Linux and Windows 95/98 on a Pentium, MacOS and Apple's Rhapsody/NeXT/UNIX on a PowerPC, and Sun Solaris on a UltraSparc 10 workstation.
Date: January 25, 2000
Creator: Sanders, D.; Riley, C.; Cremaldi, L.; Summers, D. & Petravick, D.
Object Type: Article
System: The UNT Digital Library
Recent Results on J/{psi}, {psi}(2S) and {Upsilon}production at CDF (open access)

Recent Results on J/{psi}, {psi}(2S) and {Upsilon}production at CDF

CDF has obtained new results on quarkonium production in p{anti p} collisions at {radical}s = 1.8 TeV. The author reports on measurements of {Upsilon} meson production, {Upsilon}(1S) production from {chi}{sub b} feeddown, and the production polarization of {Upsilon}(1S), J/{psi} and {psi}(2S) mesons.
Date: January 25, 2000
Creator: Cropp, R.
Object Type: Article
System: The UNT Digital Library
Simulation of Npn and Pnp AlGaN/GaN heterojunction bipolar transistors performances: Limiting factors and optimum design (open access)

Simulation of Npn and Pnp AlGaN/GaN heterojunction bipolar transistors performances: Limiting factors and optimum design

The performance capabilities of Npn and Pnp AlGaN/GaN heterojunction bipolar transistors have been investigated by using a drift-diffusion transport model. Numerical results have been employed to study the effect of the p-type Mg doping and its incomplete ionization on device performance. The high base resistance induced by the deep acceptor level is found to be the cause of limited current gain values for Npn devices. Several computation approaches have been considered to improve their performance. Reasonable improvement of the DC current gain {beta} is observed by realistically reducing the base thickness in accordance with processing limitations. Base transport enhancement is also predicted by the introduction of a quasi-electric field in the base. The impact of the base resistivity on high-frequency characteristics is investigated for Npn AlGaN/GaN devices. Optimized predictions with maximum oscillation frequency value as high as f{sub MAX} = 20 GHz and a unilateral power gain--U = 25 dB make this bipolar GaN-based technology compatible with communication applications. Simulation results reveal that the restricted amount of free carriers from the p-doped emitter limits Pnp's DC performances operating in common emitter configuration. A preliminary analysis of r.f. characteristics for the Pnp counterpart indicates limited performance mainly caused by the degraded …
Date: April 25, 2000
Creator: MONIER,C.; REN,F.; HAN,JUNG; CHANG,PING-CHIH; SHUL,RANDY J.; LEE,K.P. et al.
Object Type: Article
System: The UNT Digital Library