Month

51 Matching Results

Results open in a new window/tab.

United Nations Reform Initiatives: Answers to Hearings Questions (open access)

United Nations Reform Initiatives: Answers to Hearings Questions

Correspondence issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO provided information related to the June 22, 1999, hearing on the nomination of Richard C. Holbrooke to be Ambassador to the United Nations, focusing on United Nations reform issues related to: (1) organizational restructuring; (2) reducing overhead; (3) development dividend; (4) the oversight and monitoring of program effectiveness; (5) sunset provisions for program mandates; and (6) personnel."
Date: July 7, 1999
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
General Services Administration: Information on Pricing Retail Packaging Products (open access)

General Services Administration: Information on Pricing Retail Packaging Products

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a legislative requirement, GAO examined the General Services Administration's (GSA) retail packaging products program, focusing on whether: (1) GSA is required by law to set its prices for retail packaging products at levels sufficient to ensure that all selling costs are recovered on each item; and (2) GSA's selling prices for these items do recover all costs."
Date: July 7, 1999
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
Year 2000 Computing Challenge: Readiness Improving But Much Work Remains to Avoid Disruption of Critical Services (open access)

Year 2000 Computing Challenge: Readiness Improving But Much Work Remains to Avoid Disruption of Critical Services

Testimony issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO discussed the progress being made in addressing the year 2000 computing challenge, focusing on: (1) the federal government's progress and the challenges that remain in correcting its systems; (2) state and local government year 2000 issues; and (3) the readiness of key public infrastructure and economic sectors."
Date: July 7, 1999
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
The Wylie News (Wylie, Tex.), Vol. 53, No. 6, Ed. 1 Wednesday, July 7, 1999 (open access)

The Wylie News (Wylie, Tex.), Vol. 53, No. 6, Ed. 1 Wednesday, July 7, 1999

Weekly newspaper from Wylie, Texas that includes local, state and national news along with advertising.
Date: July 7, 1999
Creator: Engbrock, Chad B.
Object Type: Newspaper
System: The Portal to Texas History
The Clifton Record (Clifton, Tex.), Vol. 104, No. 54, Ed. 1 Wednesday, July 7, 1999 (open access)

The Clifton Record (Clifton, Tex.), Vol. 104, No. 54, Ed. 1 Wednesday, July 7, 1999

Semi-weekly newspaper from Clifton, Texas that includes local, state, and national news along with advertising.
Date: July 7, 1999
Creator: Smith, W. Leon
Object Type: Newspaper
System: The Portal to Texas History
The Seminole Sentinel (Seminole, Tex.), Vol. 92, No. 75, Ed. 1 Wednesday, July 7, 1999 (open access)

The Seminole Sentinel (Seminole, Tex.), Vol. 92, No. 75, Ed. 1 Wednesday, July 7, 1999

Semiweekly newspaper from Seminole, Texas that includes local, state, and national news along with advertising.
Date: July 7, 1999
Creator: Dow, M. Gene & Fisher, David
Object Type: Newspaper
System: The Portal to Texas History
Development of lean premixed low-swirl burner for low NO{sub x} practical application (open access)

Development of lean premixed low-swirl burner for low NO{sub x} practical application

Laboratory experiments have been performed to evaluate the performance of a premixed low-swirl burner (LSB) in configurations that simulate commercial heating appliances. Laser diagnostics were used to investigate changes in flame stabilization mechanism, flowfield, and flame stability when the LSB flame was confined within quartz cylinders of various diameters and end constrictions. The LSB adapted well to enclosures without generating flame oscillations and the stabilization mechanism remained unchanged. The feasibility of using the LSB as a low NO{sub x} commercial burner has also been verified in a laboratory test station that simulates the operation of a water heater. It was determined that the LSB can generate NO{sub x} emissions < 10 ppm (at 3% O{sub 2}) without significant effect on the thermal efficiency of the conventional system. The study has demonstrated that the lean premixed LSB has commercial potential for use as a simple economical and versatile burner for many low emission gas appliances.
Date: July 7, 1999
Creator: Yegian, D. T. & Cheng, R. K.
Object Type: Article
System: The UNT Digital Library
Retrospective application of online catalog author authority control: A pilot project (open access)

Retrospective application of online catalog author authority control: A pilot project

A total of 56 author authority records were created or revised in the Fermilab online catalog. An example of a correct author authority record is given. Since the author authority records used 400 fields and thus pipe all the variant names to the one record, any additions of records with any of these variants will be handled by the online catalog. It is likely that we have included most of the common variants of key Fermilab authors' names, so the database should stay cleaner and more functional for years to come. This project was a success. Therefore an immediate future plan is to implement additional author authority records for the remainder of the authors in the database. Afterwards, authority maintenance should be built in to Library work processes as an ongoing task.
Date: July 7, 1999
Creator: Berkhout, Therese A. & Tompson, Sara R.
Object Type: Report
System: The UNT Digital Library
Design of the Main Injector extraction beamlines (open access)

Design of the Main Injector extraction beamlines

The Main Injector (MI) supports the Tevatron Fixed Tar- get and Proton-Antiproton Collider modes of operation as well as providing 120 GeV/c resonantly extracted beam for the Main Injector Fixed Target Program. A set of beam transport lines, called Al and Pl, from the Main Injector converge on the injection point of the Tevatron, with the Al being used to transport 150 GeV/c antipro- tons (pbars) to the Tevatron. Pl is used to transport 150 GeV/c protons to the Tevatron, 120 GeV/c protons to the pbar target, and eventually 120 GeV/c resonantly ex- tracted protons to the existing Fixed Target areas. In ad- dition, the Pl line will be used to transport 8.9 GeV/c pbars from the Source back to the MI and recycled 150 GeV/c pbars at the end of Collider stores. In order to ac- complish the second and third function, the Pl beamline is continued beyond the Tevatron injection point in a sec- tion of the decommissioned Main Ring, called the P2 beamline. This transports the protons to a magnetic switch used to select either the modified transport line, used for targeting protons for pbar production, or the transport line which connects to the existing Fixed Target …
Date: July 7, 1999
Creator: Johnson, David E.
Object Type: Article
System: The UNT Digital Library
MOCVD Growth of AlGaInN for UV Emitters (open access)

MOCVD Growth of AlGaInN for UV Emitters

Issues related to the growth of nitride-based UV emitters are investigated in this work. More than 100 times of improved in the optical efficiency of the GaN active region can be attained with a combination of raising the growth pressure and introducing a small amount of indium. The unique issue in the UV emitter concerning the use of AlGaN for confinement and the associated tensile cracking is also investigated. They showed that the quaternary AlGaInN is potentially capable of providing confinement to GaN and GaN:In active regions while maintaining lattice matching to GaN, unlike the AlGaN ternary system.
Date: July 7, 1999
Creator: Crawford, Mary & Han, Jung
Object Type: Article
System: The UNT Digital Library
Fabrication of High Performance Microlenses for an Integrated Capillary Channel Electrochromatograph with Fluorescence Detection (open access)

Fabrication of High Performance Microlenses for an Integrated Capillary Channel Electrochromatograph with Fluorescence Detection

We describe the microfabrication of an extremely compact optical system as a key element in an integrated capillary channel electrochromatograph with fluorescence detection. The optical system consists of a vertical cavity surface-emitting laser (VCSEL), two high performance microlenses and a commercial photodetector. The microlenses are multilevel diffractive optics patterned by electron beam lithography and etched by reactive ion etching in fused silica. The design uses substrate-mode propagation within the fused silica substrate. Two generations of optical subsystems are described. The first generation design has a 6 mm optical length and is integrated directly onto the capillary channel-containing substrate. The second generation design separates the optical system onto its own substrate module and the optical path length is further compressed to 3.5 mm. The first generation design has been tested using direct fluorescence detection with a 750 nm VCSEL pumping a 10{sup {minus}4}M solution of CY-7 dye. The observed signal-to-noise ratio of better than 100:1 demonstrates that the background signal from scattered pump light is low despite the compact size of the optical system and is adequate for system sensitivity requirements.
Date: July 7, 1999
Creator: Wendt, J. R.; Warren, M. E.; Sweatt, W. C.; Bailey, C. G.; Matzke, C. M.; Arnold, D. W. et al.
Object Type: Article
System: The UNT Digital Library
Measurement of the triple differential jet cross section at {square root} s = 1800 GeV (open access)

Measurement of the triple differential jet cross section at {square root} s = 1800 GeV

We present a measurement of the triple differential cross section for dijet production in proton-antiproton scattering at a center of mass energy of 1800 GeV. The data were taken with the D0 detector at the Fermilab Tevatron and are compared to next to leading order QCD theoretical predictions with differing parton distribution functions. The data are of sufficient accuracy to rule out or favor parton distribution functions over a wide range in x .
Date: July 7, 1999
Creator: Schellman, H.
Object Type: Article
System: The UNT Digital Library
Optimization of Blazed Quantum Grid Infrared Photodetectors (open access)

Optimization of Blazed Quantum Grid Infrared Photodetectors

In a quantum grid infrared photodetector (QGIP), the active multiple quantum well material is patterned into a grid structure. The purposes of the grid are on the one hand to create additional lateral electron confinement and on the other to convert part of the incident light into parallel propagation. With these two unique functions, a QGIP allows intersubband transition to occur in all directions. In this work, we focused on improving the effectiveness of a QGIP in redirecting the propagation of light using a blazed structure. The optimization of the grid parameters in terms of the blaze angle and the periodicity was performed by numerical simulation using the modal transmission-line theory and verified by experiment. With a blazed structure, the sensitivity of a QGIP can be improved by a factor of 1.8 compared with a regular QGIP with rectangular profiles.
Date: July 7, 1999
Creator: Chen, C. J.; Choi, K. K.; Jiang, M.; Rokhinson, L. P.; Tamir, T.; Tsui, D. C. et al.
Object Type: Article
System: The UNT Digital Library
Ernest Orlando Berkeley National Laboratory - Fundamental and applied research on lean premixed combustion (open access)

Ernest Orlando Berkeley National Laboratory - Fundamental and applied research on lean premixed combustion

Ernest Orland Lawrence Berkeley National Laboratory (Berkeley Lab) is the oldest of America's national laboratories and has been a leader in science and engineering technology for more than 65 years, serving as a powerful resource to meet Us national needs. As a multi-program Department of Energy laboratory, Berkeley Lab is dedicated to performing leading edge research in the biological, physical, materials, chemical, energy, environmental and computing sciences. Ernest Orlando Lawrence, the Lab's founder and the first of its nine Nobel prize winners, invented the cyclotron, which led to a Golden Age of particle physics and revolutionary discoveries about the nature of the universe. To this day, the Lab remains a world center for accelerator and detector innovation and design. The Lab is the birthplace of nuclear medicine and the cradle of invention for medical imaging. In the field of heart disease, Lab researchers were the first to isolate lipoproteins and the first to determine that the ratio of high density to low density lipoproteins is a strong indicator of heart disease risk. The demise of the dinosaurs--the revelation that they had been killed off by a massive comet or asteroid that had slammed into the Earth--was a theory developed here. …
Date: July 7, 1999
Creator: Cheng, Robert K.
Object Type: Report
System: The UNT Digital Library
First Observation of Mechanochromism at the Nanometer Scale (open access)

First Observation of Mechanochromism at the Nanometer Scale

A mechanically-induced color transition (''mechanochromism'') in polydiacetylene thin films has been generated at the nanometer scale using the tips of two different scanning probe microscopes. A blue-to-red chromatic transition in polydiacetylene molecular trilayer films, polymerized from 10,12-pentacosadiynoic acid (poly-PCDA), was found to result from shear forces acting between the tip and the poly-PCDA molecules, as independently observed with near-field scanning optical microscopy and atomic force microscopy (AFM). Red domains were identified by a fluorescence emission signature. Transformed regions as small as 30 nm in width were observed with AFM. The irreversibly transformed domains preferentially grow along the polymer backbone direction. Significant rearrangement of poly-PCDA bilayer segments is observed by AFM in transformed regions. The removal of these segments appears to be a characteristic feature of the transition. To our knowledge, this is the first observation of nanometer-scale mechanochromism in any material.
Date: July 7, 1999
Creator: Carpick, R. W.; Sasaki, D. Y. & Burns, A. R.
Object Type: Article
System: The UNT Digital Library
Geothermal Drilling Organization (open access)

Geothermal Drilling Organization

The Geothermal Drilling Organization (GDO), founded in 1982 as a joint Department of Energy (DOE)-Industry organization, develops and funds near-term technology development projects for reducing geothermal drilling costs. Sandia National Laboratories administers DOE funds to assist industry critical cost-shared projects and provides development support for each project. GDO assistance to industry is vital in developing products and procedures to lower drilling costs, in part, because the geothermal industry is small and represents a limited market.
Date: July 7, 1999
Creator: Sattler, A.R.
Object Type: Article
System: The UNT Digital Library
Adhesion, Deformation and Friction for Self-Assembled Monolayers on Au and Si Surfaces (open access)

Adhesion, Deformation and Friction for Self-Assembled Monolayers on Au and Si Surfaces

Using Interracial Force Microscopy (IFM), we investigated the tribological behavior of hexadecanethiol monolayer on Au and films of octadecyltrichlorosilane (ODTS), perfluorodecyltrichlorosilane (PFTS) and dodecane on Si. We observe a strong correlation between hysteresis in a compression cycle (measured via nanoindentation) and friction. Additionally, we suggest that the amount of hysteresis and friction in each film is related to its detailed molecular structure, especially the degree of molecular packing.
Date: July 7, 1999
Creator: Houston, J. E.; Hsung, R. P.; Kiely, J. D.; Mulder, J. A. & Zhu, X. Y.
Object Type: Article
System: The UNT Digital Library
Oxygen-Induced Restructuring of Rutile TiO(2)(110): Formation Mechanism, Atomic Models, and Influence on Surface Chemistry (open access)

Oxygen-Induced Restructuring of Rutile TiO(2)(110): Formation Mechanism, Atomic Models, and Influence on Surface Chemistry

The rutile TiO{sub 2} (110) (1x1) surface is considered the prototypical ''well-defined'' system in the surface science of metal oxides. Its popularity results partly from two experimental advantages: bulk-reduced single crystals do not exhibit charging, and stoichiometric surfaces--as judged by electron spectroscopes--can be prepared reproducibly by sputtering and annealing in oxygen. We present results that show that this commonly-applied preparation procedure may result in a surface structure that is by far more complex than generally anticipated. Flat, (1x1) terminated surfaces are obtained by sputtering and annealing in ultrahigh vacuum. When re-annealed in oxygen at moderate temperatures (470 K to 660 K), irregular networks of partially-connected, pseudohexagonal rosettes (6.5 x 6 {angstrom} wide), one-unit cell wide strands, and small ({approximately} tens of {angstrom}) (1x1) islands appear. This new surface phase is formed through reaction of oxygen gas with interstitial Ti from the reduced bulk. Because it consists of an incomplete, kinetically-limited (1x1) layer, this phenomenon has been termed restructuring. We report a combined experimental and theoretical study that systematically explores this restructuring process. The influence of several parameters (annealing time, temperature, pressure, sample history, gas) on the surface morphology is investigated using STM. The surface coverage of the added phase as …
Date: July 7, 1999
Creator: Li, Min; Hebenstreit, Wilhelm; Diebold, Ulrike; Henderson, Michael A. & Jennison, Dwight R.
Object Type: Article
System: The UNT Digital Library
Solicitation - Geothermal Drilling Development and Well Maintenance Projects (open access)

Solicitation - Geothermal Drilling Development and Well Maintenance Projects

Energy (DOE)-industry research and development (R and D) organization, sponsors near-term technology development projects for reducing geothermal drilling and well maintenance costs. Sandia National Laboratories (Albuquerque, NM) administers DOE funds for GDO cost-shared projects and provides technical support. The GDO serves a very important function in fostering geothermal development. It encourages commercialization of emerging, cost-reducing drilling technologies, while fostering a spirit of cooperation among various segments of the geothermal industry. For Sandia, the GDO also serves as a means of identifying the geothermal industry's drilling fuel/or well maintenance problems, and provides an important forum for technology transfer. Successfully completed GDO projects include: the development of a high-temperature borehole televiewer, high-temperature rotating head rubbers, a retrievable whipstock, and a high-temperature/high-pressure valve-changing tool. Ongoing GDO projects include technology for stemming lost circulation; foam cement integrity log interpretation, insulated drill pipe, percussive mud hammers for geothermal drilling, a high-temperature/ high-pressure valve changing tool assembly (adding a milling capability), deformed casing remediation, high- temperature steering tools, diagnostic instrumentation for casing in geothermal wells, and elastomeric casing protectors.
Date: July 7, 1999
Creator: Sattler, A.R.
Object Type: Article
System: The UNT Digital Library
Detection of Galactic Dark Matter by GLAST (open access)

Detection of Galactic Dark Matter by GLAST

The mysterious dark matter has been a subject of special interest to high energy physicists, astrophysicists and cosmologists for many years. According to theoretical models, it can make up a significant fraction of the mass of the Universe. One possible form of galactic dark matter, Weakly Interacting Massive Particles (WIMPs), could be detected by their annihilation into monoenergetic gamma-ray line(s). This paper will demonstrate that the Gamma-ray Large Area Space Telescope (GLAST), scheduled for launch in 2005 by NASA, will be capable of searching for these gamma-ray lines in the energy range from 20 GeV to {approx}500 GeV and will be sufficiently sensitive to test a number of models. The required instrument performance and its capability to reject backgrounds to the required levels are explicitly discussed.
Date: July 7, 1999
Creator: Bloom, Elliott D
Object Type: Report
System: The UNT Digital Library
Photorefractivity in liquid crystals doped with a soluble conjugated polymer. (open access)

Photorefractivity in liquid crystals doped with a soluble conjugated polymer.

Photoconductive polymers are doped into liquid crystals to create a new mechanism for space-charge field formation in photorefractive liquid crystal composites. The composites contain poly(2,5-bis(2{prime}-ethylhexyloxy)-1,4-phenylenevinylene) (BEH-PPV) and the electron acceptor N,N{prime}-dioctyl-1,4:5,8-naphthalenediimide, NI. Using asymmetric energy transfer (beam coupling) measurements that are diagnostic for the photorefractive effect, the direction of beam coupling as a function of grating fringe spacing inverts at a spacing of 5.5 {micro}m. We show that the inversion is due to a change in the dominant mechanism for space-charge field formation. At small fringe spacings, the space-charge field is formed by ion diffusion in which the photogenerated anion is the more mobile species. At larger fringe spacings, the polarity of the space charge field inverts due to dominance of a charge transport mechanism in which photogenerated holes are the most mobile species due to hole migration along the BEH-PPV chains coupled with interchain hole hopping. Control experiments are presented, which use composites that can access only one of the two charge transport mechanisms. The results show that charge migration over long distances leading to enhanced photorefractive effects can be obtained using conjugated polymers dissolved in liquid crystals.
Date: July 7, 1999
Creator: Niemczyk, M. P.; Svec, W. A.; Wasielewski, M. R. & Wiederrecht, G. P.
Object Type: Article
System: The UNT Digital Library
Progress Toward E-157: A 1 GeV Plasma Wakefield Accelerator (open access)

Progress Toward E-157: A 1 GeV Plasma Wakefield Accelerator

A plasma based wakefield acceleration (PWFA) experiment, scheduled to run this summer, will accelerate parts of a 28.5 GeV bunch from the SLAC linac by up to 1 GeV over a length of 1 meter. A single 28.5 GeV bunch will both induce the wakefields in the one meter long plasma and witness the resulting acceleration fields. The experiment will explore and further develop the techniques that are needed to apply high-gradient PWFA to large scale accelerators. This paper summarizes the goals of the first round of experiments as well as the status of the individual components: construction and diagnosis of the homogeneous lithium oven plasma source and associated ionization laser, commissioning of the electron beam, simulated performance of the electron beam energy measurement, and first PIC simulations of the full meter long experiment.
Date: July 7, 1999
Creator: Assmann, R
Object Type: Report
System: The UNT Digital Library
Levelland and Hockley County News-Press (Levelland, Tex.), Vol. 21, No. 28, Ed. 1 Wednesday, July 7, 1999 (open access)

Levelland and Hockley County News-Press (Levelland, Tex.), Vol. 21, No. 28, Ed. 1 Wednesday, July 7, 1999

Semiweekly newspaper from Levelland, Texas that includes local, state, and national news along with advertising.
Date: July 7, 1999
Creator: Rigg, John
Object Type: Newspaper
System: The Portal to Texas History
The Baytown Sun (Baytown, Tex.), Vol. 77, No. 214, Ed. 1 Wednesday, July 7, 1999 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 77, No. 214, Ed. 1 Wednesday, July 7, 1999

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: July 7, 1999
Creator: Dobbs, Gary
Object Type: Newspaper
System: The Portal to Texas History