APPLICATIONS OF SNAP REACTOR SYSTEMS TO COMMUNICATIONS SATELLITES (open access)

APPLICATIONS OF SNAP REACTOR SYSTEMS TO COMMUNICATIONS SATELLITES

Methods are presented for determining the electric power requirements of a given communications mission in terms of mission and orbit parameters. Analyses were made of possible applications of available and projected space auxiliary power units in these satellites. The satellitc as a communication node is discussed. Example calculations are given. (M.C.G.)
Date: July 30, 1962
Creator: Wimmer, R.E.
Object Type: Report
System: The UNT Digital Library
High resolution difference schemes for compressible gas dynamics (open access)

High resolution difference schemes for compressible gas dynamics

The advantages and disadvantages of four new high-resolution difference schemes, namely the von Neumann-Richtmyer, Godunovs, MUSCL and Glimms, for mathematically representing physical conditions in compressible gas flows are compared. (LCL)
Date: July 30, 1980
Creator: Woodward, P. & Colella, P.
Object Type: Article
System: The UNT Digital Library
Future engineering needs of mirror fusion reactors (open access)

Future engineering needs of mirror fusion reactors

Fusion research has matured during the last decade and significant insight into the future program needs has emerged. While some will properly note that the crystal ball is cloudy, it is equally important to note that the shape and outline of our course is discernable. In this short summary paper, I will draw upon the National Mirror Program Plan for mirror projects and on available design studies of these projects to put the specific needs of the mirror program in perspective.
Date: July 30, 1982
Creator: Thomassen, K.I.
Object Type: Article
System: The UNT Digital Library
Savannah River Site computing architecture migration guide (open access)

Savannah River Site computing architecture migration guide

The SRS Computing Architecture is a vision statement for site computing which enumerates the strategies which will guide SRS computing efforts for the 1990s. Each strategy is supported by a number of feature statements which clarify the strategy by providing additional detail. Since it is a strategic planning document, the Architecture has sitewide applicability and endorsement but does not attempt to specify implementation details. It does, however, specify that a document will be developed to guide the migration from the current site environment to that envisioned by the new architecture. The goal of this document, the SRS Computing Architecture Migration Guide, is to identify specific strategic and tactical tasks which would have to be completed to fully implement the architectural vision for site computing as well as a recommended sequence and timeframe for addressing these tasks. It takes into account the expected availability of technology, the existing installed base, and interdependencies among architectural components and objectives.
Date: July 30, 1991
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Model validation and sensitivity analysis of solar collector loops. Final technical report (open access)

Model validation and sensitivity analysis of solar collector loops. Final technical report

The experimental solar collector systems at Middlebury College have been modified to permit short time resolution studies of solar collector loop performance. A variety of experiments have been performed to measure the following system properties: (a) collector efficiency, (b) collector response to step changes in insolation, (c) collector response to the introduction of cold inlet water, and (d) pump cycling as a function of control sensor location and set points. Data from these experiments have been supplied to the solar group at Drexel for validation of their analytical collector loop model.
Date: July 30, 1980
Creator: unknown
Object Type: Report
System: The UNT Digital Library
D7H-test results (open access)

D7H-test results

Data were reduced from the voltage-time relations stored in files D7H001 to D7H090 on HP1000. The I-B calibration curve is included. The data base is shown and can be used by the 9845B. The data include the quench location, Q/sub 2/ layer 1 top, Q/sub 3/ layer 1 bottom and the quench current and its normalized value with respect to short sample, I/sub c/ = 4920A at 4.4 K, I/sub c/ = 6710 A at 1.8 K. The resistance (..cap omega../cm) was calculated using the propagation time according to the voltage change across the measured sections. The conductor potential length are L/sub 5/ /sub 9/ = 48.6 cm, L/sub 6/ /sub 10/ = 17.9 cm, L/sub 7/ /sub 11/ = 40.6 cm. The turn to turn velocity V/sub t/ was calculated dividing the nominal turn to turn distance (58 mil) by the propagation time (Trans. Time). The quench time T/sub q/ was measured from the time the resistive rise starts until the energy extraction system fires.
Date: July 30, 1982
Creator: Caspi, S.
Object Type: Report
System: The UNT Digital Library
Double-mode pulsation (open access)

Double-mode pulsation

Double mode pulsation is a very pervasive phenomenon in stars all over the Hertzsprung-Russell diagram. In order of increasing radius, examples are: ZZ Ceti stars, the sun, the delta Scuti stars, RR Lyrae variables, the ..beta.. Cephei variables and those related to them, Cepheids, and maybe even the Mira stars. These many modes have been interpreted as both radial and nonradial modes, but in many cases the actual mode has not been clearly identified. Yellow giants seem to be the most simple pulsators with a large majority of the RR Lyrae variables and Cepheids showing only one pulsation period. We limit this review to those very few cases for classical Cepheids and RR Lyrae variables which display two modes. For these we know many facts about these stars, but the actual cause of the pulsation in two modes simultaneously remains unknown.
Date: July 30, 1982
Creator: Cox, A. N.
Object Type: Article
System: The UNT Digital Library
Study on reduction of accessory horsepower requirements. Fourth quarterly progress report (open access)

Study on reduction of accessory horsepower requirements. Fourth quarterly progress report

The program objective is to evolve and define an accessory drive system that will minimize system power consumption of driven accessories on an internal combustion engine in a passenger automobile. The initial three program phases established concept feasibility, determined potential fuel savings, and selected a drive system design for concept mechanization. During this quarter the major program accomplishments were: selection of candidate belt-drive concepts; completion of Phase III baseline vehicle drive systems physical and operational envelopes; completion of analysis for a mechanically controlled direct-operated belt drive with input programming; and completion of design layout and analysis for a hydromechanically controlled, servo-operated belt drive with output-speed sensing. (LLL)
Date: July 30, 1975
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Geothermal development and land use/energy planning by the State of California and its political subdivisions (open access)

Geothermal development and land use/energy planning by the State of California and its political subdivisions

California law contains several vehicles for the implementation of geothermal planning. These mechanisms and their impact are examined. First, at the State level upon the California Energy Commission and the Division of Oil and Gas in the Department of Conservation. After some background on county planning in California, the unique situation in the counties of greatest geothermal potential is presented: Imperial County and the four Geysers counties as well as their joint powers agency. Conclusions and recommendations are included. (MHR)
Date: July 30, 1978
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Investigation of the cryogenic mechanical properties of low thermal-expansion superalloys (open access)

Investigation of the cryogenic mechanical properties of low thermal-expansion superalloys

Four Fe-based superalloys, JBK-75, Incoloy 903, Incoloy 905, and Incoloy 909 were evaluated as tube materials for ICCS Nb/sub 3/Sn superconductors. Evaluation consisted of 4-K tensile and elastic-plastic fracture-toughness testing, and a microstructural characterization of unwelded and autogenously gas-tungsten-arc welded sheet given a simulated postweld processing treatment of 15% cold reduction by rolling followed by a Nb/sub 3/Sn-reaction heat treatment of 96 hours at 700/sup 0/C plus 48 hours at 730/sup 0/C. Results indicate that JBK-75 and Incoloy 903 showed satisfactory combinations of strength and toughness for ICCS tube use requiring long Nb/sub 3/Sn-reaction heat treatments. Incoloy 905 welds and 909 showed unacceptable fracture toughness. Results are discussed in terms of microstructural changes caused by the extended Nb/sub 3/Sn-reaction heat treatment.
Date: July 30, 1985
Creator: Summers, L.T. & Dalder, E.N.C.
Object Type: Article
System: The UNT Digital Library
Polarizability corrections in stimulated Raman propagation (open access)

Polarizability corrections in stimulated Raman propagation

Traditional descriptions of stimulated Raman scattering relate the various Stokes and anti-Stokes fields to the incident pump field by means of a polarizability (tensor). This description is usable for pulsed radiation but it fails when the pump carrier frequency coincides with a resonant frequency of the medium. We here describe a simple procedure for correcting the traditional polarizability approximation for pulse envelopes so as to account for effects of finite pump bandwidth. The correction amounts to the introduction of an auxiliary field envelope that incorporates pump dispersion. We apply this procedure to the equations for a degenerate, Doppler broadened ensemble of three-level atoms, in which the uppermost (virtual) level is close to resonance with the pump carrier frequency. This system becomes a two-level Raman system, but with a correction to the Raman Hamiltonian and the propagation equation. The plane-wave propagation equations presented include dispersive as well as Raman effects, and allow arbitrary combinations of field polarizations. We comment on several incidental aspects of Raman propagation, including dynamic Stark shifts, sublevel averages and fluence equations.
Date: July 30, 1991
Creator: Shore, B. W.; Johnson, M. A. & Lowder, S.
Object Type: Report
System: The UNT Digital Library
Coal surface control for advanced fine coal flotation (open access)

Coal surface control for advanced fine coal flotation

The primary objective in the scope of this research project is to develop advanced flotation methods for coal cleaning in order to achieve near total pyritic-sulfur removal at 90% Btu recovery, using coal samples procured from three major US coal seams. Concomitantly, the ash content of these coals is to be reduced to 6% or less. Investigation of mechanisms for the control of coal and pyrite surfaces prior to fine coal flotation is the main aspect of the project objectives. The results of this research are to be made available to ICF Kaiser Engineers who are currently working on the Engineering Development of Advanced Flotation under a separate contract with DOE under the Acid Rain Control Initiative program. A second major objective is to investigate factors involved in the progressive weathering and oxidation of coal that had been exposed to varying degrees of weathering, namely, open to the atmosphere, covered and in an argon-inerted'' atmosphere, over a period of twelve months. After regular intervals of weathering, samples of the three base coals (Illinois No. 6, Pittsburgh No. 8 and Upper Freeport PA) were collected and shipped to both the University of Pittsburgh and the University of California at Berkeley for …
Date: July 30, 1991
Creator: Fuerstenau, D. W.; Sastry, K. V. S.; Hanson, J. S.; Diao, J.; De, A.; Sotillo, F. et al.
Object Type: Report
System: The UNT Digital Library
Double-exposure collector system. Technical progress report, April 1-June 30, 1979 (open access)

Double-exposure collector system. Technical progress report, April 1-June 30, 1979

A retrofit solar water-heating system has been installed in a three-story apartment building at Drexel University. The system employs two conventional collector banks (10 PPG collectors) mounted at the latitude angle for Philadelphia of 40 deg from the horizontal and two double-exposure collectors (DEC's) mounted vertically in mirrored enclosures. Although the DEC units are being used for year-round domestic water heating for the building, they are designed to provide maximum output in the winter and are therefore well-suited to solar space heating applications. Instrumentation for testing the two types of collectors has been operating in the apartment building for some time. Summer performance data have been obtained which indicate that, at a minimum, the DEC units will provide twice as much useful heat output per panel as conventional collectors. In addition some results for an overcast day showed that comparable relative performance could be expected on these days.
Date: July 30, 1979
Creator: Larson, D. C. & Savery, C. W.
Object Type: Report
System: The UNT Digital Library
(Development of high spectral resolution lidar technology) (open access)

(Development of high spectral resolution lidar technology)

The first year of this grant has been devoted to the design and construction of an upgraded version of the University of Wisconsin High Spectral Resolution Lidar (HSRL). The new system incorporates additional data channels to measure depolarization and multiple scattering in the lidar return. Schematic diagrams describing the new configurations are attached to this report. Increases in optical efficiency and receiver aperture, coupled with improvements in the stiffness and the thermal stability of the mechanical system are expected to significantly improve the performance of the instrument. Most components of the system are nearly completed and system integration is about to begin. The HSRL is committed to participate in the NASA FIRE cirrus experiment during November and December of this year. Our progress is completing HSRL subsystems is outlined in the following paragraphs. 3 figs.
Date: July 30, 1991
Creator: Eloranta, E.W.
Object Type: Report
System: The UNT Digital Library
Streamlining the Federal geothermal leasing and permitting process: background papers, analysis and recommendations (open access)

Streamlining the Federal geothermal leasing and permitting process: background papers, analysis and recommendations

The federal leasing and permitting programs were analyzed as well as those of the five states in the Pacific Region. The relevant statutoring and regulatory frameworks of the land management agencies involved were also analyzed, as well as the options prepared by the DOE Streamlining Task Force and the California State-Federal-Local Task Group. The present stationary responsibilities and management structure of the Forest Service, BLM, and the Pacific Region States, as well as the roles of DOE and DOD. (MHR)
Date: July 30, 1978
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Photochemistry and enzymology of photosynthesis (open access)

Photochemistry and enzymology of photosynthesis

In the first task, a specially designed mass spectrometer system monitors the gas exchange occurring in response to single short flashes of light. This apparatus will be primarily used to study photosystem II donor reactions, such as the photooxidation of hydroxylamine, hydrazine, and hydrogen peroxide. This technique will also be used to study the light-induced exchange of O/sub 2/ and CO/sub 2/ in algae. The second task, biochemical studies, will focus on the role of chloroplast copper in photosynthesis. We propose to isolate, purify, and characterize the chloroplast copper enzyme polyphenol oxidase, and attempt to elucidate its role in photosynthesis. These studies will be integrated with a new program devoted to the biochemical response of the photosynthetic membrane to stress. The third task is a series of studies on the light-harvesting and electron-transport mechanisms of C/sub 4/ plants. This program will address three basic problems: (1) the effect of different preparative procedures on various photosynthetic reactions, with particular emphasis on photosystem II reactions in corn bundle sheath chloroplasts; (2) the development and testing of photosystem II assays; and (3) studies of the stoichiometry of electron carriers in bundle sheath chloroplasts, and whether cyclic phosphorylation could be a major pathway in …
Date: July 30, 1979
Creator: Radmer, R.
Object Type: Report
System: The UNT Digital Library
Low-temperature geothermal resource and stratigraphy of portions of Yakima County, Washington (open access)

Low-temperature geothermal resource and stratigraphy of portions of Yakima County, Washington

The low-temperature geothermal resource of portions of Yakima County, south-central Washington, is defined by several least squares linear regression analyses of bottom-hole temperature and depth data. Intra-borehole flow prevents the use of borehole temperature gradients for geothermal resource assessment. Bottom-hole temperature and depth data were separated into fourteen well data groups based on geographic proximity, land slope azimuth, and position within the regional ground-water flow system. The regression analyses of these well data groups indicate that the projected land-surface temperature and geothermal gradient range from 10.6 to 14.0/sup 0/C and from 24.9 to 52.2/sup 0/C/km, respectively. The depth to the 20/sup 0/C isotherm ranges from 142 to 346m. The average projected land-surface temperature and geothermal gradient are approximately 11.3/sup 0/C and 43.0/sup 0/C/km, respectively. The average depth to the 20/sup 0/C isoterm is approximately 202m. The projected land-surface temperature appears to decrease and the depth to the 20/sup 0/C isotherm appears to increase as the land-surface elevation of the well dat group increases. Stratigraphic correlation diagrams developed from borehole geophysical and lithologic logs are given for localities within the lower Yakima, Black Rock, Moxee, Ahtanum, Cowiche, and Naches valleys. These correlation diagrams are combined with their respective borehole temperatue logs …
Date: July 30, 1982
Creator: Biggane, J.
Object Type: Report
System: The UNT Digital Library
Sensitivity study of reliable, high-throughput resolution metricsfor photoresists (open access)

Sensitivity study of reliable, high-throughput resolution metricsfor photoresists

The resolution of chemically amplified resists is becoming an increasing concern, especially for lithography in the extreme ultraviolet (EUV) regime. Large-scale screening and performance-based down-selection is currently underway to identify resist platforms that can support shrinking feature sizes. Resist screening efforts, however, are hampered by the absence of reliable resolution metrics that can objectively quantify resist resolution in a high-throughput fashion. Here we examine two high-throughput metrics for resist resolution determination. After summarizing their details and justifying their utility, we characterize the sensitivity of both metrics to two of the main experimental uncertainties associated with lithographic exposure tools, namely: limited focus control and limited knowledge of optical aberrations. For an implementation at EUV wavelengths, we report aberration and focus limited error bars in extracted resolution of {approx} 1.25 nm RMS for both metrics making them attractive candidates for future screening and down-selection efforts.
Date: July 30, 2007
Creator: Anderson, Christopher N. & Naulleau, Patrick P.
Object Type: Article
System: The UNT Digital Library
Patterns and Implications of Gene Gain and Loss in the Evolution of Prochlorococcus (open access)

Patterns and Implications of Gene Gain and Loss in the Evolution of Prochlorococcus

Prochlorococcus is a marine cyanobacterium that numerically dominates the mid-latitude oceans and is the smallest known oxygenic phototroph. Numerous isolatesfrom diverse areas of the world's oceans have been studied and shown to be physiologically and genetically distinct. All isolates described thus far can be assigned to either a tightly clustered high-light (HL)-adapted clade, or a more divergent low-light (LL)-adapted group. The 16S rRNA sequences of the entire Prochlorococcus group differ by at most 3percent, and the four initially published genomes revealed patterns of genetic differentiation that help explain physiological differences among the isolates. Here we describe the genomes of eight newly sequenced isolates and combine them with the first four genomes for a comprehensive analysis of the core (shared by all isolates) and flexible genes of the Prochlorococcus group, and the patterns of loss and gain of the flexible genes over the course of evolution. There are 1,273 genes that represent the core shared by all 12 genomes. They are apparently sufficient, according to metabolic reconstruction, to encode a functional cell. We describe a phylogeny for all 12 isolates by subjecting their complete proteomes to three different phylogenetic analyses. For each non-core gene, we used a maximum parsimony method to …
Date: July 30, 2007
Creator: Lapidus, Alla; Kettler, Gregory C.; Martiny, Adam C.; Huang, Katherine; Zucker, Jeremy; Coleman, Maureen L. et al.
Object Type: Article
System: The UNT Digital Library
STOUT SMEARING FOR TWISTED FERMIONS. (open access)

STOUT SMEARING FOR TWISTED FERMIONS.

The effect of Stout smearing is investigated in numerical simulations with twisted mass Wilson quarks. The phase transition near zero quark mass is studied on 12{sup 3} x 24, 16{sup 3} x 32 and 24{sup 3} x 48 lattices at lattice spacings a {approx_equal} 0.1-0.125 fm. The phase structure of Wilson fermions with twisted mass ({mu}) has been investigated in [1,2]. As it is explained there, the observed first order phase transition limits the minimal pion mass which can be reached in simulations at a given lattice spacing: m{sub k}{sup min} {approx_equal} {theta}(a). The phase structure is schematically depicted in the left panel of Fig. I . The phase transition can be observed in simulations with twisted mass fermions, for instance, as a ''jump'' or even metastabilities in the average plaquette value as a function of the hopping parameter ({kappa}). One possibility to weaken the phase transition and therefore allow for lighter pion masses at a given lattice spacing is to use an improved gauge action like the DBW2, Iwasaki, or tree-level Symanzik (tlSym) improved gauge action instead of the simple Wilson gauge action. This has been successfully demonstrated in [3,4,5]. Here we report on our attempts to use a …
Date: July 30, 2007
Creator: SCHOLZ,W.; JANSEN, K.; McNEILE, C.; MONTVAY, I.; RICHARDS, C.; URBACH, C. et al.
Object Type: Article
System: The UNT Digital Library
Spectral Properties of Quarks in the Quark-Gluon Plasma (open access)

Spectral Properties of Quarks in the Quark-Gluon Plasma

We analyze the spectral properties of the quark propagator above the critical temperature for the deconfinement phase transition in quenched lattice QCD using clover improved Wilson fermions. The bare quark mass dependence of the quark spectral function is analyzed by varying the hopping parameter {kappa} in Landau gauge. We assume a two-pole structure for the quark spectral function, which is numerically found to work quite well for any value of {kappa}. It is shown that in the chiral limit the quark spectral function has two collective modes that correspond to the normal and plasmino excitations, while it is dominated by a single-pole structure when the bare quark mass becomes large.
Date: July 30, 2007
Creator: Karsch, F. & Kitazawa, M.
Object Type: Article
System: The UNT Digital Library
21st Century Locomotive Technology: Quarterly Technical Status Report 22 DOE/AL68284-TSR22 (open access)

21st Century Locomotive Technology: Quarterly Technical Status Report 22 DOE/AL68284-TSR22

Sodium battery thermal model completed, and validation started.
Date: July 30, 2008
Creator: Salasoo, Lembit
Object Type: Report
System: The UNT Digital Library
Calculation of drift seepage for alternative emplacementdesigns (open access)

Calculation of drift seepage for alternative emplacementdesigns

The calculations presented in this report are performed to obtain seepage rates into drift and boreholes for two alternative designs of drift and waste emplacement at Yucca Mountain. The two designs are defined according to the Scope of Work 14012021M1, activity 399621, drafted October 6, 1998, and further refined in a conference telephone call on October 13, 1998, between Mark Balady, Jim Blink, Rob Howard and Chin-Fu Tsang. The 2 designs considered are: (1) Design A--Horizontal boreholes 1.0 m in diameter on both sides of the drift, with each borehole 8 m long and inclined to the drift axis by 30 degrees. The pillar between boreholes, measured parallel to the drift axis, is 3.3 m. In the current calculations, a simplified model of an isolated horizontal borehole 8 m long will be simulated. The horizontal borehole will be located in a heterogeneous fracture continuum representing the repository layer. Three different realizations will be taken from the heterogeneous field, representing three different locations in the rock. Seepage for each realization is calculated as a function of the percolation flux. Design B--Vertical boreholes, 1.0 m in diameter and 8.0 m deep, drilled from the bottom of an excavated 8.0 m diameter drift. …
Date: July 30, 1999
Creator: Li, Guomin; Tsang, Chin-Fu & Birkholzer, Jens
Object Type: Report
System: The UNT Digital Library
Extensive Set of Low-Fidelity Covariances in Fast Neutron Region. (open access)

Extensive Set of Low-Fidelity Covariances in Fast Neutron Region.

An extensive set of covariances for neutron cross sections has been developed to provide initial, low-fidelity but consistent uncertainty data for nuclear criticality safety applications. The methodology for the determination of such covariances in fast neutron region is presented. It combines the nuclear reaction code EMPIRE, which calculates sensitivity to nuclear reaction model parameters and the Bayesian code KALMAN to propagate uncertainty of the model parameters onto cross sections. Taking into account the large scale of the project (219 fission products), only partial reference to experimental data has been made. Therefore, the covariances are, to a large extent, derived from the perturbation of several critical model parameters selected through the sensitivity analysis. They define optical potential, level densities and pre-equilibrium emission. This exercise represents the first attempt to generate nuclear data covariances on such a scale.
Date: July 30, 2007
Creator: Pigni, M. T.; Herman, M.; Oblozinsky, P. & Rochman, D.
Object Type: Article
System: The UNT Digital Library