Feasibility of Measuring the Cosmological Constant [LAMBDA]and Mass Density [Omega]using Type Ia Supernovae (open access)

Feasibility of Measuring the Cosmological Constant [LAMBDA]and Mass Density [Omega]using Type Ia Supernovae

We explore the feasibility of resurrecting the apparent magnitude-redshift relation for a 'standard candle' to measure the cosmological constant and mass density. We show that type Ia supernovae, if measured with 0.15 mag uncertainty out to a redshift of z = 1, may provide a good standard candle or calibrated candle for this purpose. The recent discovery of probable type Ia supernovae in the redshift range z = 0.3 to 0.5 (Perlmutter et al. 1994a, and 1994b) indicates that the flux of optical photons from these events can be measured this accurately. The 7 distant supernovae discovered to date do not by themselves distinguish between different cosmological models, however the further discovery of about 50 type Ia supernovae at redshifts in the range 0.5 < z {approx} 1.0 could strongly constrain the allowed range of these parameters. We estimate that the follow-up photometry necessary for this measurement would be on the order of 20 - 70 hours of time on a lO-meter class telescope at a site with good seeing.
Date: April 1, 1995
Creator: Goobar, A. & Perlmutter, S.
Object Type: Article
System: The UNT Digital Library
Design of a relativistic Klystron Two-Beam Accelerator Prototype (open access)

Design of a relativistic Klystron Two-Beam Accelerator Prototype

We are designing an experiment to study physics, engineering, and costing issues of an extended Relativistic Klystron Two-Beam Accelerator (RK-TBA). The experiment is a prototype for an RK-TBA based microwave power source suitable for driving a 1 TeV linear collider. Major components of the experiment include a 2.5-MV, 1.5-kA electron source, a 11.4-GHz modulator, a bunch compressor, and a 8-m extraction section. The extraction section will be comprised of 4 traveling-wave output structures, each generating about 360 MW of rf power. Induction cells will be used in the extraction section to maintain the average beam energy at 5 MeV. Status of the design is presented.
Date: April 1, 1995
Creator: Westenskow, G.; Caporaso, G.; Chen, Y.; Houck, T.; Yu, S.; Chattopadhyay, S. et al.
Object Type: Article
System: The UNT Digital Library
Technical evaluation report for the demonstration of radio frequency soil decontamination at Site S-1 (open access)

Technical evaluation report for the demonstration of radio frequency soil decontamination at Site S-1

The Air Force`s Armstrong Laboratory at Tyndall Air Force Base, Florida, has supported the research and development of Radio Frequency Soil Decontamination. Radio frequency soil decontamination is essentially a heat-assisted soil vapor extraction process. Site S-1 at Kelly Air Force Base, San Antonio, Texas, was selected for the demonstration of two patented techniques. The site is a former sump that collected spills and surface run-off from a waste petroleum, oils, and lubricants and solvent storage and transfer area. In 1993, a technique developed by the IIT Research Institute using an array of electrodes placed in the soil was demonstrated. In 1994, a technique developed by KAI Technologies, Inc. using a single applicator placed in a vertical borehole was demonstrated. Approximately 120 tons of soil were heated during each demonstration to a temperature of about 150 degrees Celsius.
Date: April 1, 1995
Creator: Lyon, Chesley R.; Blanchard, Clifton F. & Whitt, Laura H.
Object Type: Report
System: The UNT Digital Library
Radionuclide air emissions annual report for calendar year 1994 (open access)

Radionuclide air emissions annual report for calendar year 1994

This report presents the results of the Pinellas Plant air sampling program for the year of 1994. Topics discussed include: site description; source description; air emissions data; dose assessments; description of dose model; summary of input parameters of dose model; unplanned releases; and diffuse emissions. Included in the attachments of this document are: non-radon individual dose assessment; non-radon population dose assessment; summary of stack flow rate measurements; HOTSPOT computer model run; and meteorological data for the Pinellas Plant for 1994.
Date: April 4, 1995
Creator: unknown
Object Type: Report
System: The UNT Digital Library
D0 Silicon Upgrade: Helium and LN2 Storage Requirements for D-Zero Upgrade (open access)

D0 Silicon Upgrade: Helium and LN2 Storage Requirements for D-Zero Upgrade

Calculations were done to determine a recommended size for the liquid helium storage dewar, gas helium storage tanks, and liquid nitrogen dewar requirements. I recommend a Liquid helium storage dewar with a nominal size of at least 2500 liters (660 gallons), preferably 3000 liters (792 gallons). I recommend obtaining gas helium storage tanks with a maximum allowable working pressure (MA WP) of 250 psig or greater. Combined volume to be at least 5880 cubic feet (44,000 gallons). I recommend obtaining a second liquid nitrogen dewar at D-Zero, dedicated to the refrigerator, solenoid and VLPC systems. The ideal dewar would have a volume of around 16,000 gallons. It's MAWP needs to be greater than 55 psig.
Date: April 4, 1995
Creator: Rucinski, Russ
Object Type: Report
System: The UNT Digital Library
Laminin Mediates Tissue-specific Gene Expression in Mammary Epithelia (open access)

Laminin Mediates Tissue-specific Gene Expression in Mammary Epithelia

Tissue-specific gene expression in mammary epithelium is dependent on the extracellular matrix as well as hormones. There is good evidence that the basement membrane provides signals for regulating beta-casein expression, and that integrins are involved in this process. Here, we demonstrate that in the presence of lactogenic hormones, laminin can direct expression of the beta-casein gene. Mouse mammary epithelial cells plated on gels of native laminin or laminin-entactin undergo functional differentiation. On tissue culture plastic, mammary cells respond to soluble basement membrane or purified laminin, but not other extracellular matrix components, by synthesizing beta-casein. In mammary cells transfected with chloramphenicol acetyl transferase reporter constructs, laminin activates transcription from the beta-casein promoter through a specific enhancer element. The inductive effect of laminin on casein expression was specifically blocked by the E3 fragment of the carboxy terminal region of the alpha 1 chain of laminin, by antisera raised against the E3 fragment, and by a peptide corresponding to a sequence within this region. Our results demonstrate that laminin can direct tissue-specific gene expression in epithelial cells through its globular domain.
Date: April 1, 1995
Creator: Streuli, Charles H; Schmidhauser, Christian; Bailey, Nina; Yurchenco, Peter; Skubitz, Amy P. N.; Roskelley, Calvin et al.
Object Type: Article
System: The UNT Digital Library
Two Alternate High Gradient Quadrupoles; An Upgraded Tevatron IR and A"Pipe" Design (open access)

Two Alternate High Gradient Quadrupoles; An Upgraded Tevatron IR and A"Pipe" Design

With the U.S. cancellation of the SSC project, the only large approved hadron accelerator project is CERN's LHC. One of the more critical elements in the performance of a collider is the quadrupole lens at the beam collision points. These quadrupoles, usually referred to as the 'insertion quads' normally form a set of triplets around the interaction region. Their focal power directly affects the luminosity available at the crossing point In order to achieve as high a gradient as possible, the CERN design team has proposed a very efficient high gradient quadrupole which is based on a graded four-layer winding structure. At Fermilab's Tevatron, an upgraded two layer winding quadrupole has been in operation since 1989, and has provided a 50% higher gradient than its predecessor. The quadrupole was basically state of the art when it was designed in 1985. Since then however, improvements have been made in cabling, conductor perfonnance, etc. Naturally, operation of a modernized version of this .design can provide higher capabilities. This improved two layer design can serve as an alternative to the more intricate graded four layer design now envisioned for the LHC, provided it can obtain the proposed gradient. A high gradient quadrupole with …
Date: April 1, 1995
Creator: McInturff, A. D.; van Oort, J. M. & Scanlan, R. M.
Object Type: Report
System: The UNT Digital Library
Tunable Free-Electron Lasers (open access)

Tunable Free-Electron Lasers

None
Date: April 1, 1995
Creator: Benson, Stephen
Object Type: Report
System: The UNT Digital Library
Lawrence Berkeley Laboratory FY 1995 site development plan (open access)

Lawrence Berkeley Laboratory FY 1995 site development plan

This report is a site development plan detailing the mission of LBL, its workload and site population, program projections and requirements, master plans, and management considerations.
Date: April 14, 1995
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Visual display of reservoir parameters affecting enhanced oil recovery. Quarterly report, April 1995--June 1995. 2nd Quarter, FY 1995 (open access)

Visual display of reservoir parameters affecting enhanced oil recovery. Quarterly report, April 1995--June 1995. 2nd Quarter, FY 1995

This report describes the development of a Spatial Database Manager (SDBM) shell/interface which will provide information to users on how to collect, store, analyze, interpret, visualize and present data in an integrated reservoir characterization study. SDBM will provide access to various geologic, reservoir visual data via a well log interpretation program (Crocker Petrolog), mapping and cross section software ( the GeoGraphix Exploration System Workbench) and a volume visualization application. Data tables for geochemical and petrographic data, well logs, well header information, well production data, formation tops, and fault trace data have been completed. Spectral mineral data are currently being collected which will ultimately be used for identification of mineral assemblages. The geochemical program CHILLER is being used to model fluid-rock interactions and possibly porosity predictions.
Date: April 5, 1995
Creator: Wood, J.R.
Object Type: Report
System: The UNT Digital Library
Low Energy Accelerator Laboratory Technical Area 53, Los Alamos National Laboratory. Environmental assessment (open access)

Low Energy Accelerator Laboratory Technical Area 53, Los Alamos National Laboratory. Environmental assessment

This Environmental Assessment (EA) analyzes the potential environmental impacts that would be expected to occur if the Department of Energy (DOE) were to construct and operate a small research and development laboratory building at Technical Area (TA) 53 at the Los Alamos National Laboratory (LANL), Los Alamos, New Mexico. DOE proposes to construct a small building to be called the Low Energy Accelerator Laboratory (LEAL), at a previously cleared, bladed, and leveled quarter-acre site next to other facilities housing linear accelerator research activities at TA-53. Operations proposed for LEAL would consist of bench-scale research, development, and testing of the initial section of linear particle accelerators. This initial section consists of various components that are collectively called an injector system. The anticipated life span of the proposed development program would be about 15 years.
Date: April 1, 1995
Creator: unknown
Object Type: Report
System: The UNT Digital Library
A refuelable zinc/air battery for fleet electric vehicle propulsion (open access)

A refuelable zinc/air battery for fleet electric vehicle propulsion

We report the development and on-vehicle testing of an engineering prototype zinc/air battery. The battery is refueled by periodic exchange of spent electrolyte for zinc particles entrained in fresh electrolyte. The technology is intended to provide a capability for nearly continuous vehicle operation, using the fleet s home base for 10 minute refuelings and zinc recycling instead of commercial infrastructure. In the battery, the zinc fuel particles are stored in hoppers, from which they are gravity fed into individual cells and completely consumed during discharge. A six-celled (7V) engineering prototype battery was combined with a 6 V lead/acid battery to form a parallel hybrid unit, which was tested in series with the 216 V battery of an electric shuttle bus over a 75 mile circuit. The battery has an energy density of 140 Wh/kg and a mass density of 1.5 kg/L. Cost, energy efficiency, and alternative hybrid configurations are discussed.
Date: April 20, 1995
Creator: Cooper, J.F.; Fleming, D.; Hargrove, D.; Koopman, R. & Peterman, K.
Object Type: Article
System: The UNT Digital Library
Effect of temperature on perchloroethylene dechlorination by a methanogenic consortium (open access)

Effect of temperature on perchloroethylene dechlorination by a methanogenic consortium

The effect of temperature on the kinetics of growth, substrate metabolism, and perchloroethylene (PCE) dechlorination by a methanogenic consortium is reported. In all cases, a simple kinetic model accurately reflected experimental data. Values for the substrate and methane yield coefficients, and the maximum specific growth rate are fairly consistent at each temperature. Also, the substrate and methane yield coefficients show little temperature sensitivity. In contrast, both the maximum specific growth rate and the PCE dechlorination yield coefficient (Y{sub PCE}) are temperature dependent.
Date: April 1, 1995
Creator: Gao, J.; Skeen, R. S. & Hooker, B. S.
Object Type: Article
System: The UNT Digital Library
Simulation of ionic surfaces from an absolutely convergent solution of the Madelung problem (open access)

Simulation of ionic surfaces from an absolutely convergent solution of the Madelung problem

The classic Madelung problem is cast into an absolutely convergent form that is readily evaluated by direct lattice summation, revealing a net r{sup {minus}5} range of the net Coulomb potential in ionic crystals and liquids. The realization that Coulomb interactions in condensed systems can actually be rather short ranged (provided the system is overall neutral) leads to the prediction, verified by computer simulations for rocksalt-structure surfaces, that all surfaces in predominantly ionic crystals should be fundamentally reconstructed. The work also provides a conceptual framework for the theoretical treatment of polar surfaces, as demonstrated for the case of the (111) surfaces of NaCl and MgO.
Date: April 1, 1995
Creator: Wolf, D.
Object Type: Article
System: The UNT Digital Library
Workshop in computational molecular biology, April 15, 1991--April 14, 1994 (open access)

Workshop in computational molecular biology, April 15, 1991--April 14, 1994

Funds from this award were used to the Workshop in Computational Molecular Biology, `91 Symposium entitled Interface: Computing Science and Statistics, Seattle, Washington, April 21, 1991; the Workshop in Statistical Issues in Molecular Biology held at Stanford, California, August 8, 1993; and the Session on Population Genetics a part of the 56th Annual Meeting, Institute of Mathematical Statistics, San Francisco, California, August 9, 1993.
Date: April 12, 1995
Creator: Tavare, S.
Object Type: Article
System: The UNT Digital Library
Energy & technology review, April 1995 (open access)

Energy & technology review, April 1995

This publication presents research overviews on projects from the Lawrence Livermore laboratory. This issue provides information on microsphere targets for inertial confinement fusion experiments; laser fabrication of berllium components; and the kinetic energy interceptor.
Date: April 1, 1995
Creator: Bookless, W. A. & Stull, S.
Object Type: Report
System: The UNT Digital Library
Assessment of Noble Gases in the Savannah River Site Environment (open access)

Assessment of Noble Gases in the Savannah River Site Environment

A series of documents has been published that assesses the impact of various radionuclides released to the environment by Savannah River Site operations. The quantity released, the disposition of the radionuclides in the environment, and the dose to offsite individuals has been presented for carbon, cesium, iodine, plutonium, strontium, technetium, tritium, and uranium. An assessment of the impact of non-radioactive mercury also has been published.
Date: April 1995
Creator: Carlton, W. H. & Murphy, C. E. Jr.
Object Type: Report
System: The UNT Digital Library
The Sloan Digital Sky Survey`s use of the Web (open access)

The Sloan Digital Sky Survey`s use of the Web

The Sloan Digital Sky Survey is a world-wide collaboration in astrophysics with contributors from around the United States, Italy, and Japan. Collaborators need to have easy access to current information about the project and the on-going software development. The World Wide Web (WWW) and HTML (HyperText Markup Language meet this need admirably. Our use of the Web can be thought of as providing access to three distinct types of information: (1) the infrastructure of the project, (2) the documentation of actual software used throughout the project, and (3) access to Survey databases. The layout of Web pages is not meant to allow the public to easily surf. Rather, the pages are laid out to permit collaborators to find information efficiently. In keeping with this goal, there is less emphasis on glitz and more on content.
Date: April 1, 1995
Creator: Petravick, D.; Berman, E. & Gurbani, V.
Object Type: Article
System: The UNT Digital Library
Structure and composition of clean and hydrogen covered MoRe surfaces (open access)

Structure and composition of clean and hydrogen covered MoRe surfaces

The clean and hydrogen covered (100) and (110) faces of Mo{sub 0.75}Re{sub 0.23} alloy single crystals show 1x1 structures. By means of LEED structure analyses we have determined the interlayer distances as well as the layer concentrations down to the sixth layer. While the clean (110) surface turns out to be nearly bulklike terminated, the clean (100) face is found to exhibit both an extended oscillatory layer relaxation and composition profile. Hydrogen adsorption at low temperatures does not alter the composition profile and removes the small remaining relaxation for the (110) surface. In case of the (100) face a substancial reduction of the relaxation is observed for the outermost layer distances as well, while deeper layer relaxations are preserved indicating a strong coupling off relaxation and composition profiles. Hydrogen is found to adsorb in quasi-threefold coordinated sites for the (110) and bridge sites for the (100) face.
Date: April 1, 1995
Creator: Hammer, L.; Meyer, S. & Rath, C.
Object Type: Article
System: The UNT Digital Library
Results of the supplementary radiological survey at the former C. H. Schnoor and Company site, 644 Garfield Street, Springdale, Pennsylvania (CVP001) (open access)

Results of the supplementary radiological survey at the former C. H. Schnoor and Company site, 644 Garfield Street, Springdale, Pennsylvania (CVP001)

At the request of the U.S. Department of Energy (DOE), a team from Oak Ridge National Laboratory conducted radiological surveys at the former C. H. Schnoor and Company site, 644 Garfield Street, Springdale, Pennsylvania. The surveys were performed on October 11-13 and November 14-17, 1993, in order to provide a complete characterization prior to site remediation. The surveys included a gamma scan and a scan for surface contamination from alpha and beta-gamma emitters; measurement of direct and removable alpha and beta-gamma levels; systematic FIDLER measurements at the surface of the concrete; and the collection of samples from boreholes for radionuclide analysis. Results of the surveys revealed radionuclide concentrations and surface contamination levels in excess of applicable DOE guidelines for {sup 238}U. Radionuclide distributions were higher than typical background levels for {sup 238}U in the Springdale, Pennsylvania area.
Date: April 1, 1995
Creator: Coleman, R. L.; Murray, M. E. & Brown, K. S.
Object Type: Report
System: The UNT Digital Library
Anisotropy and spatial variation of relative permeability and lithologic character of Tensleep Sandstone reservoirs in the Bighorn and Wind River Basins, Wyoming. Second quarterly, second year, technical progress report, January 1, 1995--March 31, 1995 (open access)

Anisotropy and spatial variation of relative permeability and lithologic character of Tensleep Sandstone reservoirs in the Bighorn and Wind River Basins, Wyoming. Second quarterly, second year, technical progress report, January 1, 1995--March 31, 1995

This study is designed to provide improvements in reservoir characterization techniques. Activities include: an examination of the spatial variation and anisotropy of relative permeability in the Tensleep Sandstone reservoirs of Wyoming; the placement of that variation and anisotropy into paleogeographic, depositional and diagenic frameworks; the development of pore system imagery techniques for the calculation of relative permeability; and reservoir simulations testing the impact of permeability and anisotropy on enhanced oil recovery. Results are described.
Date: April 13, 1995
Creator: Dunn, T. L.
Object Type: Report
System: The UNT Digital Library
Research methods to develop measures of effectiveness of the United States Coast Guard`s Vessel Inspection and Boarding Program, Volume 1 - executive summary (open access)

Research methods to develop measures of effectiveness of the United States Coast Guard`s Vessel Inspection and Boarding Program, Volume 1 - executive summary

The primary objective of this study is to provide Measures of Effectiveness (MOEs) of the U.S. Coast Guard Marine Inspection and Boarding Program based on objective scientific methods. A secondary objective of the study is to provide USCG management with a methodologically and theoretically sound aid to effective policy decision-making. The MOEs constructed in this study are specific to the Marine Inspection and Boarding Program, but the methodology of the study is based on sound theoretical principles that are probably applicable to a range of USCG activities. Hence the methodology applies equally to other important USCG programs and can be similarly used to measure their effectiveness and as an aid to decision-making.
Date: April 1, 1995
Creator: Wheeler, T.; Cox, R. & Gawande, K.
Object Type: Report
System: The UNT Digital Library
Prognostic atmospheric and dispersion modeling in the vicinity of Rocky Flats Plant (open access)

Prognostic atmospheric and dispersion modeling in the vicinity of Rocky Flats Plant

A multiscale four-dimensional data assimilation technique is incorporated into a mesoscale model and evaluated using meteorological and tracer data collected during the Atmospheric Studies in Complex Terrain (ASCOT) field experiment in the winter of 1991. The mesoscale model is used to predict the interaction of synoptically-driven flows and small-scale circulations influenced by terrain along the Front Range in Colorado in the vicinity of the Rocky Flats Plant for four nocturnal periods during the ASCOT field experiment. Data assimilation is used to create dynamically consistent analysis fields based on the mesoscale forecasts and the special asynoptic data taken during this experiment. The wind and turbulence quantities produced by the mesoscale model are then used to determine the dispersion of a tracer released from the Rocky Flats Plant for each evening. The mesoscale model is able to qualitatively predict the mesobeta-scale drainage flows from the Front Range into the South Platte River basin; however, the largest forecast errors occurred in a region immediately adjacent to the foothills. As expected, the current data assimilation technique reduced the overall errors in the atmospheric and dispersion calculations while the model generated realistic small-scale circulations not resolved by the data. Still, the model did not capture …
Date: April 1, 1995
Creator: Fast, J.D.
Object Type: Article
System: The UNT Digital Library
An optically-triggered semiconductor switch for high power laser beams (open access)

An optically-triggered semiconductor switch for high power laser beams

The work involves research leading to an optically triggered switch for a high power laser pulse. The switch uses a semiconductor heterostructure whose optical properties are modified by a low power laser trigger such as a laser diode. Potential applications include optical control of pulsed power systems, control of medical lasers and implementation of security features in optical warhead architectures.
Date: April 1995
Creator: Chow, Weng W. & Warren, M. E.
Object Type: Report
System: The UNT Digital Library