105 Matching Results

Search Results

Results: 1 - 24 next
open access

Radiation-driven evolution of low-mass x-ray binaries and the formation of millisecond pulsars

Description: Recent data on low-mass X-ray binaries (LMXBs) and millisecond pulsars (MSPs) pose a challenge to evolutionary theories which neglect the effects of disk and comparison irradiation. Here we discuss the main features of a radiation-driven (RD) evolutionary model that may be applicable to several LMXBs. According to this model, radiation from the accreting compact star in LMXBs vaporizes'' the accretion disk and the companion star by driving a self-sustained mass loss until a sudden accretion-tur… more
Date: August 8, 1991
Creator: Tavani, M. (Lawrence Livermore National Lab., CA (United States) California Univ., Berkeley, CA (United States). Dept. of Astronomy)
Partner: UNT Libraries Government Documents Department
open access

Probing Late Neutrino Mass Properties With SupernovaNeutrinos

Description: Models of late-time neutrino mass generation contain new interactions of the cosmic background neutrinos with supernova relic neutrinos (SRNs). Exchange of an on-shell light scalar may lead to significant modification of the differential SRN flux observed at earth. We consider an Abelian U(1) model for generating neutrino masses at low scales, and show that there are cases for which the changes induced in the flux allow one to distinguish the Majorana or Dirac nature of neutrinos, as well as th… more
Date: August 8, 2007
Creator: Baker, Joseph; Goldberg, Haim; Perez, Gilad & Sarcevic, Ina
Partner: UNT Libraries Government Documents Department
open access

The Genome of the Epsilonproteobacterial Chemolithoautotroph Sulfurimonas dentrificans

Description: Sulfur-oxidizing epsilonproteobacteria are common in a variety of sulfidogenic environments. These autotrophic and mixotrophic sulfur-oxidizing bacteria are believed to contribute substantially to the oxidative portion of the global sulfur cycle. In order to better understand the ecology and roles of sulfur-oxidizing epsilonproteobacteria, in particular those of the widespread genus Sulfurimonas, in biogeochemical cycles, the genome of Sulfurimonas denitrificans DSM1251 was sequenced. This geno… more
Date: August 8, 2007
Creator: Class, USF Genomics; Sievert, Stefan M.; Scott, Kathleen M.; Klotz, Martin G.; Chain, Patrick S.G.; Hauser, Loren J. et al.
Partner: UNT Libraries Government Documents Department
open access

Design and Construction of Test Coils for the MICE Coupling Solenoid Magnet

Description: The superconducting coupling solenoid to be applied in the Muon Ionization Cooling Experiment (MICE) is made from copper matrix Nb-Ti conductors with inner radius of 750 mm, length of 285 mm and thickness of 102.5 mm at room temperature. The magnetic field up to 2.6 T at the magnet centerline is to keep the muons within the MICE RF cavities. Its self inductance is around 592 H and its magnet stored energy is about 13 MJ at a full current of 210 A for the worst operation case of the MICE channel… more
Date: August 8, 2008
Creator: Wang, Li; Pan, Heng; Xu, F.Y.; Liu, XioaKun; Chen, AnBin; Li, LanKai et al.
Partner: UNT Libraries Government Documents Department
open access

Use of Conducting Polymers for Electronic Communication with Redox Active Nanoparticles

Description: Nanoscale materials provide unique properties that will enable new technologies and enhance older ones. One area of intense activity in which nanoscale materials are being used is in the development of new functional materials for battery applications.1-4 This effort promises superior materials with properties that circumvent many of the problems associated with traditional battery materials. Previously we have worked on several approaches for using nanoscale materials for application as cathod… more
Date: August 8, 2004
Creator: Bazito, Fernanda; O'Brien, Robert & Buttry, Daniel A.
Partner: UNT Libraries Government Documents Department
open access

Simple Stringy Dynamical SUSY Breaking

Description: We present simple string models which dynamically break supersymmetry without non-Abelian gauge dynamics. The Fayet model, the Polonyi model, and the O'Raifeartaigh model each arise from D-branes at a specific type of singularity. D-brane instanton effects generate the requisite exponentially small scale of supersymmetry breaking.
Date: August 8, 2007
Creator: Aharony, Ofer; /Weizmann Inst. /Stanford U., Phys. Dept. /SLAC; Kachru, Shamit; Silverstein, Eva & /Stanford U., Phys. Dept. /SLAC
Partner: UNT Libraries Government Documents Department
open access

VERIFICATION TEST PROBLEMS

Description: We present analytic solutions to two test problems that can be used to check the hydrodynamic implementation in computer codes designed to calculate the propagation of shocks in spherically convergent geometry. Our analysis is restricted to fluid materials with constant bulk modulus. In the first problem we present the exact initial acceleration and pressure gradient at the outer surface of a sphere subjected to an exponentially decaying pressure of the form P(t) = P{sub 0}e{sup -at}. We show t… more
Date: August 8, 2007
Creator: Moran, B
Partner: UNT Libraries Government Documents Department
open access

Dislocation nucleation in bcc Ta single crystals studied by nanoindentation

Description: The study of dislocation nucleation in closed-packed metals by nanoindentation has recently attracted much interest. Here, we address the peculiarities of the incipient plasticity in body centered cubic (bcc) metals using low index Ta single-crystals as a model system. The combination of nanoindentation with high-resolution atomic force microscopy provides us with experimental atomic-scale information on the process of dislocation nucleation and multiplication. Our results reveal a unique defor… more
Date: August 8, 2007
Creator: Biener, M M; Biener, J; Hodge, A M & Hamza, A V
Partner: UNT Libraries Government Documents Department
open access

Nuclear diffractive structure functions at high energies

Description: A future high-energy electron-ion collider would explore the non-linear weakly-coupled regime of QCD, and test the Color Glass Condensate (CGC) approach to high-energy scattering. Hard diffraction in deep inelastic scattering off nuclei will provide many fundamental measurements. In this work, the nuclear diffractive structure function F{sub 2,A}{sup D} is predicted in the CGC framework, and the features of nuclear enhancement and suppression are discussed.
Date: August 8, 2008
Creator: Marquet,C.; Kowalski, H.; Lappi, T. & Venugopalan, R.
Partner: UNT Libraries Government Documents Department
open access

A Molecular Assessment of Phylogenetic Relationships and LineageDiversification Within the Family Salamandridae (Amphibia, Caudata)

Description: Phylogenetic relationships among species of the salamanderfamily Salamandridae are investigated using nearly 3000 nucleotide basesof newly reported mitochondrial DNA sequence data from the mtDNA genicregion spanning the genes tRNALeu-COI. This study uses nearlycomprehensive species-level sampling to provide the first completephylogeny for the Salamandridae. Deep phylogenetic relationships amongthe three most divergent lineages in the family Salamandrina terdigitata,a clade comprising the "True"… more
Date: August 8, 2005
Creator: Weisrock, David W.; Papenfuss, Theodore J.; Macey, J. Robert; Litvinchuk, Spartak N.; Polymeni, Rosa; Ugurtas, Ismail H. et al.
Partner: UNT Libraries Government Documents Department
open access

The characterization of Nb/sub 3/Sn superconductors for use in magnets of 19 T and greater

Description: Increased resolution of NMR spectrometry will require the use of very high field Nb/sub 3/Sn superconducting magnets. Here we report the results of our investigation into mechanical and temperature effects on internal-Sn superconductors similar to those proposed for use in a 900 MHz, 21 T NMR magnet system. Thermal precompression was found to be about 0.225%, and the irreversible strain was about 0.8%. Fatigue degradation was not observed at cyclic intrinsic strains below 0.575%. Additions of r… more
Date: August 8, 1989
Creator: Summers, L. T.; Strum, M. J. & Miller, J. R.
Partner: UNT Libraries Government Documents Department
open access

The International Thermonuclear Experimental Reactor (ITER): Design and materials selection

Description: The success of ITER relies on aggressive design of the superconducting magnet systems. This design emphasized high radiation-damage tolerance, acceptance of high nuclear heat loads, and high operational stresses in the Toroidal Field (TF) magnets. The design of the Central Solenoid (CS) magnets, although they will be well shielded from the plasma, is equally aggressive due to the need for very high magnetic fields (14 T) and long term operation at high cyclic stresses. Success of these magnet d… more
Date: August 8, 1989
Creator: Summers, L. T.; Miller, J. R. & Heim, J. R.
Partner: UNT Libraries Government Documents Department
open access

Advanced high-field coil designs: 20 TESLA

Description: This study of the technology required for producing large high-field coils has shown that, with some extensions to our present technological base, feasible designs are achievable. The resulting magnets could well make a paramount contribution to the national mirror-fusion endeavor.
Date: August 8, 1983
Creator: Hoard, R. W.; Cornish, D. N.; Scanlan, R. M.; Zbasnik, J. P.; Leber, R. L.; Hickman, R. B. et al.
Partner: UNT Libraries Government Documents Department
open access

Decommissioning a tritium glove-box facility

Description: A large glove-box facility for handling reactive metal tritides was decommissioned. Major sections of the glove box were decontaminated and disassembled for reuse at another tritium facility. To achieve the desired results, decontamnation required repeated washing, first with organic liquids, then with water and detergents. Worker protection was provided by simple ventilation combined with careful monitoring of the work areas and employees. Several innovative techniques are described.
Date: August 8, 1979
Creator: Folkers, C. L.; Homann, S. G.; Nicolosi, A. S.; Hanel, S. L. & King, W. C.
Partner: UNT Libraries Government Documents Department
open access

High performance inertial fusion targets

Description: Inertial confinement fusion (ICF) target designs are considered which may have very high gains (approximately 1000) and low power requirements (< 100 TW) for input energies of approximately one megajoule. These include targets having very low density shells, ultra thin shells, central ignitors, magnetic insulation, and non-ablative acceleration.
Date: August 8, 1978
Creator: Nuckolls, J.H.; Bangerter, R.O.; Lindl, J.D.; Mead, W.C. & Pan, Y.L.
Partner: UNT Libraries Government Documents Department
open access

The records management challenge

Description: No Description Available.
Date: August 8, 1990
Creator: Zeile, H. J.
Partner: UNT Libraries Government Documents Department
open access

X-ray diffractometry of lanthanum-nickel-aluminum alloys. Part 1

Description: X-ray diffractometry provides much useful information on LANA alloys that complements data obtained by SEM and Electron Microprobe Analysis. Accurate measurements of the hexagonal lattice parameters of the primary LaNi{sub 5-y}Aly phase reveal the aluminum content (y) and allow the prediction of desorption pressures for the hydrogen isotopes. A study of the broadening of x-ray diffraction lines of the LaNi{sub 5-y}Aly primary phase caused by cyclic absorption and desorption of hydrogen suggests… more
Date: August 8, 1988
Creator: Mosley, W. C.
Partner: UNT Libraries Government Documents Department
open access

Realizing parallel reduction operation in Sisal 1.2. Revision 1

Description: Often the tasks of a parallel job compute sets of values that are reduced to a single value or gathered to build an aggregate structure. Since reductions may introduce dependencies, most languages separate computation and reduction. For example, Fortran 90 and HPF provide a rich set of predefined reduction functions but only for extant arrays. Sisal 1.2 is unique in that it supports seven reduction operations as a natural consequence of loop expressions. These reductions are limited and cannot … more
Date: August 8, 1994
Creator: Denton, S. M.; Feo, J. T. & Miller, P. J.
Partner: UNT Libraries Government Documents Department
open access

Demonstration of zinc/air fuel battery to enhance the range and mission of fleet electric vehicles: Preliminary results in the refueling of a multicell module

Description: We report progress in an effort to develop and demonstrate a refuelable zinc/air battery for fleet electric vehicle applications. A refuelable module consisting of twelve bipolar cells with internal flow system has been refueled at rates of nearly 4 cells per minute refueling time of 10 minutes for a 15 kW, 55 kWh battery. The module is refueled by entrainment of 0.5-mm particles in rapidly flowing electrolyte, which delivers the particles into hoppers above each cell in a parallel-flow hydraul… more
Date: August 8, 1994
Creator: Cooper, J. F.; Fleming, D.; Keene, L.; Maimoni, A.; Peterman, K. & Koopman, R.
Partner: UNT Libraries Government Documents Department
open access

IUPAC Statues and Bylaws.

Description: From the history of the Commission, it began with a large number of members. It was found that it was difficult to gain agreement by correspondence between such a large group. A smaller group was elected to operate by correspondence and make decisions. It operated successfully for a half century in this manner. With funding available, the Commission membership grew larger but they.discussed all matters face to face at Commission meetings. Subcommittees were appointed to pursue specialized topic… more
Date: August 8, 2003
Creator: Holden, Norman E.
Partner: UNT Libraries Government Documents Department
open access

Chemistry at Extreme Conditions

Description: We present equation of state results from impulsively stimulated light scattering (ISLS) experiments conducted in diamond anvil cells on pure supercritical fluids. We have made measurements on fluid H{sub 2}O (water), and CH{sub 3}OH (methanol). Sound speeds measured through ISLS have allowed us to refine existing potential models used in the exponential-6 (EXP-6) detonation product library [Fried, L. E., and Howard, W. M., J. Chem. Phys. 109 (17): 7338-7348 (1998).]. The refined models allow u… more
Date: August 8, 2002
Creator: Zaug, J M; Fried, L E; Abramson, E H; Hansen, D W; Crowhurst, J C & Howard, W M
Partner: UNT Libraries Government Documents Department
open access

Itinerant and localized magnetic moments in ferrimagnetic Mn{sub 2}CoGa thin films identified with x-ray magnetic linear dichroism: experiment and ab initio theory

Description: Epitaxial thin films of the half-metallic X{sub a}-compound Mn{sub 2}CoGa (Hg{sub 2}CuTi prototype) were prepared by dc magnetron co-sputtering with different heat treatments on MgO (001) substrates. High-quality #12;lms with a bulk magnetization of 1.95(5) {mu}{sub #22;}B per unit cell were obtained. The average Mn magnetic moment and the Co moment are parallel, in agreement with theory. The x-ray magnetic circular dichroism spectra agree with calculations based on density functional theory an… more
Date: August 8, 2011
Creator: Meinert, Markus; Schmalhorst, Jan-Michael; Klewe, Cristoph; Reiss, Gunter; Arenholz, Elke; Bohnert, Tim et al.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen