Month

Language

Depth and Thermal Stability of Dry Etch Damage in GaN Schottky Diodes (open access)

Depth and Thermal Stability of Dry Etch Damage in GaN Schottky Diodes

GaN Schottky diodes were exposed to N<sub>2</sub> or H<sub>2</sub> Inductively Coupled Plasmas prior to deposition of the rectifying contact. Subsequent annealing, wet photochemical etching or (NH<sub>4</sub>)<sub>2</sub>S surface passivation treatments were examined for their effect on diode current- voltage characteristics. We found that either annealing at 750 &deg;C under N<sub>2</sub>, or removal of ~500-600 &Aring; of the surface essentially restored the initial I-V characteristics. There was no measurable improvement in the plasma-exposed diode behavior with (NH<sub>4</sub>)<sub>2</sub>S treatments.
Date: July 6, 1999
Creator: Baca, A. G.; Cao, X. A.; Cho, H.; Dang, G. T.; Hickman, R.; Pearton, S. J. et al.
Object Type: Article
System: The UNT Digital Library
Lessons learned from U.S. Department of Defense 911-Bio Advanced Concept Technology Demonstrations. (open access)

Lessons learned from U.S. Department of Defense 911-Bio Advanced Concept Technology Demonstrations.

The US Department of Defense (DoD), in cooperation with other federal agencies, has taken many initiatives to improve its ability to support civilian response to a domestic biological terrorism incident. This paper discusses one initiative, the 911-Bio Advanced Concept Technology Demonstrations (ACTDs), conducted by the Office of the Secretary of Defense during 1997 to better understand: (1) the capability of newly developed chemical and biological collection and identification technologies in a field environment; (2) the ability of specialized DoD response teams to use these new technologies within the structure of cooperating DoD and civilian consequence management organizations; and (3) the adequacy of current modeling tools for predicting the dispersal of biological hazards. This paper discusses the experience of the ACTDs from the civilian community support perspective. The 911-Bio ACTD project provided a valuable opportunity for DoD and civilian officials to learn how they should use their combined capabilities to manage the aftermath of a domestic biological terrorism incident.
Date: July 6, 1999
Creator: Baldwin, T.; Gasper, W.; Lacher, L.; Newsom, D. & Yantosik, G.
Object Type: Article
System: The UNT Digital Library
MPC and A enhancements for the Murmansk shipping company icebreaker fleet (open access)

MPC and A enhancements for the Murmansk shipping company icebreaker fleet

The United States and the Russian Federation entered into a cooperative agreement in 1994 that resulted in a nuclear weapons non-proliferation program within the United States (US) Department of Energy (DOE) currently known as the Russia/Newly Independent States (NIS) Nuclear Material Security Task Force. In 1996, a project was initiated with the Murmansk Shipping Company to enhance material protection, control, and accounting of highly enriched nuclear fuel assemblies used for the Icebreaker Fleet. The commissioning ceremony for this project is scheduled for August 1999. This paper describes the physical protection, material control, and accounting measures implemented for the Icebreaker Fleet.
Date: July 6, 1999
Creator: Bartoch, O.; Bondarev, N.; Caskey, D.; Forehand, M.; Lambert, D.; Maltsev, V. et al.
Object Type: Article
System: The UNT Digital Library
Development of Thin-Film Battery Powered Transdermal Medical Devices (open access)

Development of Thin-Film Battery Powered Transdermal Medical Devices

Research carried out at ORNL has led to the development of solid state thin-film rechargeable lithium and lithium-ion batteries. These unique devices can be fabricated in a variety of shapes and to any required size, large or small, on virtually any type of substrate. Because they have high energies per unit of volume and mass and because they are rechargeable, thin-film lithium batteries have potentially many applications as small power supplies in consumer and special electronic products. Initially, the objective of this project was to develop thin-film battery powered products. Initially, the objective of this project was to develop thin-film battery powered transdermal electrodes for recording electrocardiograms and electroencephalograms. These ''active'' electrode would eliminate the effect of interference and improve the reliability in diagnosing heart or brain malfunctions. Work in the second phase of this project was directed at the development of thin-film battery powered implantable defibrillators.
Date: July 6, 1999
Creator: Bates, J.B. & Sein, T.
Object Type: Report
System: The UNT Digital Library
Federal facilities compliance act waste management (open access)

Federal facilities compliance act waste management

Site Treatment Plans (STPs) developed through the Federal Facilities Compliance Act pose many technical and administrative challenges. Legacy wastes managed under these plans require Land Disposal Restriction (LDR) compliance through treatment and ultimate disposal. Although capacity has been defined for most of the Department of Energy wastes, many waste streams require further characterization and many need additional treatment and handling beyond LDR criteria to be able to dispose of the waste. At Lawrence Livermore National Laboratory (LLNL), the Hazardous Waste Management Division has developed a comprehensive Legacy Waste Program. The program directs work to manage low level and mixed wastes to ensure compliance with nuclear facility rules and its STP. This paper provides a survey of work conducted on these wastes at LLNL. They include commercial waste treatment and disposal, diverse forms of characterization, inventory maintenance and reporting, on-site treatment, and treatability studies. These activities are conducted in an integrated fashion to meet schedules defined in the STP. The processes managing wastes are dynamic due to required integration of administrative, regulatory, and technical concerns spanning the gamut to insure safe proper disposal.
Date: July 6, 1999
Creator: Bowers, J.; Gates-Anderson, D.; Hollister, R. & Painter, S.
Object Type: Article
System: The UNT Digital Library
Perry Daily Journal (Perry, Okla.), Vol. 106, No. 130, Ed. 1 Tuesday, July 6, 1999 (open access)

Perry Daily Journal (Perry, Okla.), Vol. 106, No. 130, Ed. 1 Tuesday, July 6, 1999

Daily newspaper from Perry, Oklahoma that includes local, state, and national news along with advertising.
Date: July 6, 1999
Creator: Brown, Gloria
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Express-Star (Chickasha, Okla.), Ed. 1 Tuesday, July 6, 1999 (open access)

The Express-Star (Chickasha, Okla.), Ed. 1 Tuesday, July 6, 1999

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date: July 6, 1999
Creator: Bush, Kent
Object Type: Newspaper
System: The Gateway to Oklahoma History
Exploring the Role of Shear Stress and Severe Turbulence in Downstream Fish Passage (open access)

Exploring the Role of Shear Stress and Severe Turbulence in Downstream Fish Passage

Fish may be exposed to damaging levels of fluid shear stress and turbulence while passing through hydroelectric power plants. The generally assumed locations for such potential damage are the turbine and draft tube passages, although it is possible that fish are also injured during passage over the spillway or through sluiceways and fish bypass outfalls. Unless mitigated, fluid-induced injuries and mortality could frustrate efforts to develop advanced, fish-friendly turbines or to provide safe alternate downstream passages. The effects of shear stress and turbulence on fish are poorly understood, in part because of the difficulties in conceptualizing these phenomena, determining their magnitudes and distribution within hydroelectric systems, and then recreating them in a controlled laboratory environment. We define the fluid phenomena that are relevant to the assessment of effects on fish. The magnitudes of fluid stresses associated with man-altered aquatic environments are often considerably higher than those found in natural environments (e.g., normal river flows). However, levels of shear stresses that occur during flash floods appear to be comparable to those expected within a turbine. Past studies of the effects of shear stress on fish are of limited value, mainly because of their narrow scope and lack of instrumentation to measure …
Date: July 6, 1999
Creator: Cada, G.; Carlson, T.; Ferguson, J.; Richmond, M. & Sale, M.
Object Type: Article
System: The UNT Digital Library
The Sealy News (Sealy, Tex.), Vol. 112, No. 55, Ed. 1 Tuesday, July 6, 1999 (open access)

The Sealy News (Sealy, Tex.), Vol. 112, No. 55, Ed. 1 Tuesday, July 6, 1999

Semiweekly newspaper from Sealy, Texas that includes local, state, and national news along with advertising.
Date: July 6, 1999
Creator: Chionsini, Brandi
Object Type: Newspaper
System: The Portal to Texas History
Transverse Mode Structure and Pattern Formation in Oxide Confined Vertical Cavity Semiconductor Lasers (open access)

Transverse Mode Structure and Pattern Formation in Oxide Confined Vertical Cavity Semiconductor Lasers

We analyze the transverse profiles of oxide-confined vertical cavity laser diodes as a function of aperture size. For small apertures we demonstrate that thermal lensing can be the dominant effect in determining the transverse resonator properties. We also analyze pattern formation in lasers with large apertures where we observe the appearance of tilted waves.
Date: July 6, 1999
Creator: Choquette, K. D.; Geib, K. M.; Hegarty, S. P.; Hou, H. Q.; Huyet, G.; McInerney, J. G. et al.
Object Type: Article
System: The UNT Digital Library
Altus Times (Altus, Okla.), Vol. 100, No. 92, Ed. 1 Tuesday, July 6, 1999 (open access)

Altus Times (Altus, Okla.), Vol. 100, No. 92, Ed. 1 Tuesday, July 6, 1999

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: July 6, 1999
Creator: Cole, Carol
Object Type: Newspaper
System: The Gateway to Oklahoma History
Hydropower Resource Assessment Modeling Results (open access)

Hydropower Resource Assessment Modeling Results

The U.S. Department of Energy�s Hydropower Program developed the Hydropower Evaluation Software to model the undeveloped hydropower resources in the United States based on environmental, legal, and institutional constraints. This Hydropower Resource Assessment effort has identified 5,677 sites that have an undeveloped total capacity of about 30,000 megawatts. The Hydropower Evaluation Software uses the Federal Energy Regulatory Commission�s Hydroelectric Power Resource Assessment database to identify sites with undeveloped hydropower capacity and the estimated megawatts of undeveloped capacity at each site. The software integrates this information with environmental values from the National Park Service�s National Rivers Inventory database. Other constraints to development that are modeled include Federal and state legislative protection for river segments that have been identified as being wild and scenic river segments. River segments containing threatened and/or endangered wildlife and fish are also modeled for their influence on hydropower development. The amount that each attribute affects the likelihood of development is dependent on the prior development of a site.
Date: July 6, 1999
Creator: Conner, A. M. & Francfort, J. E.
Object Type: Article
System: The UNT Digital Library
The Baytown Sun (Baytown, Tex.), Vol. 77, No. 213, Ed. 1 Tuesday, July 6, 1999 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 77, No. 213, Ed. 1 Tuesday, July 6, 1999

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: July 6, 1999
Creator: Dobbs, Gary
Object Type: Newspaper
System: The Portal to Texas History
Impact of Aluminum on Anticipated Corrosion in a Flooded SNF Multi Canister Overpack (MCO) (open access)

Impact of Aluminum on Anticipated Corrosion in a Flooded SNF Multi Canister Overpack (MCO)

Corrosion reactions in a flooded MCO are examined to determine the impact of aluminum corrosion products (from aluminum basket grids and spacers) on bound water estimates and subsequent fuel/environment reactions during storage. The mass and impact of corrosion products were determined to be insignificant, validating the choice of aluminum as an MCO component and confirming expectations that no changes to the Technical Databook or particulate mass or water content are necessary.
Date: July 6, 1999
Creator: Duncan, D. R.
Object Type: Report
System: The UNT Digital Library
Cold Vacuum Drying (CVD) Facility General Service Helium System Design Description (open access)

Cold Vacuum Drying (CVD) Facility General Service Helium System Design Description

This document describes the Cold Vacuum Drying Facility general service helium system (GSHe). The GSHe is a general service facility process support system, but does include safety-class systems, structures and components providing protection to the offsite public. The GSHe also performs safety-significant functions that provide protection to onsite workers. The GSHe essential function is to provide helium to support process functions during all phases of facility operations. GSHe helium is used to purge the cask and the MCO in order to maintain their internal atmospheres below hydrogen flammability concentrations. The GSHe also supplies helium to purge the PWC lines and components and the VPS vacuum pump.
Date: July 6, 1999
Creator: Farwick, C. C.
Object Type: Report
System: The UNT Digital Library
Estimates if population inversion for deep-UV transitions in Kr-like Y,Zr,Nb and Mo in a high-current reflex discharge (open access)

Estimates if population inversion for deep-UV transitions in Kr-like Y,Zr,Nb and Mo in a high-current reflex discharge

Kr-like ions are good candidates for FUV lasing since they can be produced in plasmas quite easily. We present results from a spectroscopic investigation of Y IV emission from a high current density, cold cathode reflex discharge. The Y II to Y V emission is recorded in the 200-3000 {angstrom} range using photometrically calibrated spectrometers, while the emission of trace aluminum ions serves for plasma diagnostics. The intensities of the Y IV 4d - 5p and 5s - 5p transitions strongly increase relative to lines from Y II and Y III with increasing plasma current. The spectra studied here are obtained at a current density of 1.75 A/cm{sup 2}. Experimental Y IV intensity ratios spanning several excited configurations are compared with collisional radiative predictions of the HULLAC atomic physics package. Good agreement is found for the measured and predicted ratios of 4p{sup 5}5p to 4p{sup 5}5s level populations per statistical weight. Finally, the response of the Kr-like system to a fast, transient excitation pulse is examined using the RADEX code. Large transient gains are predicted for several 5s - 5p transitions in Y IV, Zr V, Nb VI and Mo VII.
Date: July 6, 1999
Creator: Finkenthal, M.; May, M. J.; Fournier, K.; Goldstein, W. H.; Shlyaptsev, V. N.; Soukhanovskii, V. et al.
Object Type: Article
System: The UNT Digital Library
Russian Navy Fresh Fuel MPC and A Training (open access)

Russian Navy Fresh Fuel MPC and A Training

The goal of the Russian Navy Fuels Program is to incorporate nuclear fuel that is in the custody of the Russian Navy into a materials protection, control and accounting program. In addition to applying MPC and A upgrades to existing facilities, a program is underway to train site personnel in MPC and A activities. The goal is to assure that the upgraded facilities are managed, operated and maintained in an effective, sustainable manner. Training includes both the conceptual and necessary operational aspects of the systems and equipment. The project began with a Needs Assessment to identify priorities and objectives of required training. This led to the creation of a series of classes developed by Kurchatov Institute. One course was developed to allow attendees to get a general understanding of goals and objectives of nuclear MPC and A systems in the context of the Russian Navy. A follow-on course provided the detailed skills necessary for the performance of specialized duties. Parallel sessions with hands-on exercises provided the specific training needed for different personnel requirements. The courses were presented at KI facilities in Moscow. This paper reviews the work to date and future plans for this program.
Date: July 6, 1999
Creator: Forehand, Harry M.; O'Shell, Parker; Opanassiouk, Yuri R.; Rexroth, Paul E.; Shmelev, Vladimir & Sukhoruchkin, Vladimir K.
Object Type: Article
System: The UNT Digital Library
Optical determination of incipient soot particle concentrations in ethene laminar diffusion flames. (open access)

Optical determination of incipient soot particle concentrations in ethene laminar diffusion flames.

Recent studies in premixed flames have shown the existence of ''transparent particles.'' These particles, 2 nm in size and in high number densities are considered to be a phase transitional between the gas phase PAH species and particulate soot. In the present study, various optical diagnostics were evaluated for measuring the concentration of these particles in situ, Through such evaluations, a technique using extinction at two wavelengths was found to be ideal. While employing such a technique, the volume fractions of these particles in an ethene laminar diffusion flame were measured. Low in the flame, these particles were found to be concentrated in the fuel rich core, while at higher locations, they could be found with appreciable volume fractions even in the soot laden regions. Having given due consideration for the errors due to uncertainties in the optical constants, we report the existence of these particles in an ethene flame with volume fractions comparable to those of soot. Also, similar measurements performed in a low sooting ethene/methanol flame show the concentration of these particles to be of the same order of magnitude as in a pure ethene flame.
Date: July 6, 1999
Creator: Gupta, S. B. & Santoro, R. J.
Object Type: Article
System: The UNT Digital Library
Tank Monitoring and Control Sys (TMACS) Acceptance Test Procedure (open access)

Tank Monitoring and Control Sys (TMACS) Acceptance Test Procedure

This document is used to validate Revision 11.1 of the Tank Monitor and Control System (TMACS) and verify its functions as intended by design.
Date: July 6, 1999
Creator: HOLM, M.J.
Object Type: Report
System: The UNT Digital Library
Rains County Leader (Emory, Tex.), Vol. 112, No. 4, Ed. 1 Tuesday, July 6, 1999 (open access)

Rains County Leader (Emory, Tex.), Vol. 112, No. 4, Ed. 1 Tuesday, July 6, 1999

Weekly newspaper from Emory, Texas that includes local, state, and national news along with advertising.
Date: July 6, 1999
Creator: Hill, Earl Clyde, Jr.
Object Type: Newspaper
System: The Portal to Texas History
Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 84, No. 252, Ed. 1 Tuesday, July 6, 1999 (open access)

Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 84, No. 252, Ed. 1 Tuesday, July 6, 1999

Daily newspaper from Sapulpa, Oklahoma that includes local, state, and national news along with advertising.
Date: July 6, 1999
Creator: Horn, Richard A.
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Boerne Star (Boerne, Tex.), Vol. 94, No. 54, Ed. 1 Tuesday, July 6, 1999 (open access)

The Boerne Star (Boerne, Tex.), Vol. 94, No. 54, Ed. 1 Tuesday, July 6, 1999

Semiweekly newspaper from Boerne, Texas that includes local, state, and national news along with advertising.
Date: July 6, 1999
Creator: Keasling, Edna & Fierro, Jennifer
Object Type: Newspaper
System: The Portal to Texas History
Final Report: Barium Titanate/Polymer Nanoscale Composites with Controllable Architectures, September 2, 1998 - April 8, 1999 (open access)

Final Report: Barium Titanate/Polymer Nanoscale Composites with Controllable Architectures, September 2, 1998 - April 8, 1999

Final report of Phase I SBIR grant. A study of processing methods for barium titanate/polymer nanocomposites for use in dielectric applications.
Date: July 6, 1999
Creator: Luther, Eric; Slenes, Kirk; Law, Kristen; Labanowski, Christopher & Romero, Thomas
Object Type: Report
System: The UNT Digital Library
Characterization, Transport and Remedial Options for Radioactive Strontium and Cesium Contaminated Sites (open access)

Characterization, Transport and Remedial Options for Radioactive Strontium and Cesium Contaminated Sites

None
Date: July 6, 1999
Creator: Mason, C.; Lu, N. & Conca, J.
Object Type: Article
System: The UNT Digital Library