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Design and implementation of a fiber-optic gamma-measurement system

Description: The design and implementation of the downhole portion of a measuring system for gamma rays is presented. Included are three alternative designs for radiation-resistant collimating and condensing lenses, sample cells, turning mirrors, and fiber-optic termination techniques. Also discussed are mechanical mounts and positioners, shielding, alignment, test methods, and field installation. Some general design suggestions for optical systems in adverse environments are also presented.
Date: May 19, 1980
Creator: Reedy, R.P.; Crawford, D.W. & Roeske, F. Jr.
Partner: UNT Libraries Government Documents Department
open access

Inertial fusion power for space applications

Description: More than thirty-seven design concepts have been proposed for terrestrial ICF power plants. The design space is large because of the many allowable driver and reaction chamber combinations. These design studies have illustrated advantages of ICF power plants over other sources in lower impact on the environment, high safety, and almost no dependence on consumables like fuel. The fact that, once built, a 1000 MW/sub e/ ICF power plant would require only 240 kg of deuterium and from 770 to 9260 k… more
Date: May 19, 1986
Creator: Meier, W. R.; Hogan, W. J.; Hoffman, N. J.; Murray, K. A. & Olson, R. E.
Partner: UNT Libraries Government Documents Department
open access

Application of the TraPPE force field to predicting isothermal pressure-volume curves at high pressures and high temperatures

Description: Knowledge of the thermophysical properties of materials at extreme pressure and temperature conditions is essential for improving our understanding of many planetary and detonation processes. Significant gaps in what is known about the behavior of materials at high density and high temperature exist, largely due to the limitations and dangers of performing experiments at the necessary extreme conditions. Modeling these systems through the use of equations of state and particle-based simulation … more
Date: May 19, 2006
Creator: Eggimann, B L; Siepmann, J I & Fried, L E
Partner: UNT Libraries Government Documents Department
open access

Anchor Toolkit - a secure mobile agent system

Description: Mobile agent technology facilitates intelligent operation insoftware systems with less human interaction. Major challenge todeployment of mobile agents include secure transmission of agents andpreventing unauthorized access to resources between interacting systems,as either hosts, or agents, or both can act maliciously. The Anchortoolkit, designed by LBNL, handles the transmission and secure managementof mobile agents in a heterogeneous distributed computing environment. Itprovides users with t… more
Date: May 19, 1999
Creator: Mudumbai, Srilekha S.; Johnston, William & Essiari, Abdelilah
Partner: UNT Libraries Government Documents Department
open access

Measurement of the Mass Difference m(B0) - m(B+)

Description: Using 230 million B{bar B} events recorded with the BABAR detector at the e{sup +}e{sup -} storage rings PEP-II, they reconstruct approximately 4100 B{sup 0} {yields} J/{psi} K{sup +}{pi}{sup -} and 9930 B{sup +} {yields} J/{psi}K{sup +} decays with J/{psi} {yields} {mu}{sup +}{mu}{sup -} and e{sup +} e{sup -}. From the measured B-momentum distributions in the e{sup +}e{sup -} rest frame, they determine the mass difference m(B{sup 0}) - m(B{sup +}) = (+0.33 {+-} 0.05 {+-} 0.03) MeV/c{sup 2}.
Date: May 19, 2008
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department
open access

New advances in three-dimensional controlled-sourceelectromagnetic inversion

Description: New techniques for improving both the computational andimaging performance of the three dimensional (3D) electromagnetic inverseproblem are presented. A non-linear conjugate gradient algorithm is theframework of the inversion scheme. Full wave equation modelling forcontrolled sources is utilized for data simulation along with anefficient gradient computation approach for the model update. Improvingthe modelling efficiency of the 3D finite difference method involves theseparation of the potentia… more
Date: May 19, 2007
Creator: Commer, Michael & Newman, Gregory A.
Partner: UNT Libraries Government Documents Department
open access

'Shim pulses' for NMR spectroscopy in inhomogeneous magneticfields

Description: NMR spectroscopy conveys information about chemical structure through ppm-scale shifts of the resonance frequency depending on the chemical environment. In order to observe these small shifts, magnets with highly homogeneous magnetic field B{sub 0} are used. The high cost and large size of these magnets are a consequence of the requirement for high homogeneity. In this contribution we introduce a new method for recording high-resolution NMR spectra from samples in inhomogeneous B{sub 0}, openin… more
Date: May 19, 2004
Creator: Topgaard, Daniel; Martin, Rachel W.; Sakellariou, Dimitris; Meriles, Carlos & Pines, Alexander
Partner: UNT Libraries Government Documents Department
open access

Geant4 Developments And Applications

Description: No Description Available.
Date: May 19, 2006
Creator: Allison, J.; Amako, K.; Apostolakis, J.; Araujo, H.; Dubois, P.A.; Asai, M. et al.
Partner: UNT Libraries Government Documents Department
open access

The Methanosarcina barkeri genome: comparative analysis withMethanosarcina acetivorans and Methanosarcina mazei reveals extensiverearrangement within methanosarcinal genomes

Description: We report here a comparative analysis of the genome sequence of Methanosarcina barkeri with those of Methanosarcina acetivorans and Methanosarcina mazei. All three genomes share a conserved double origin of replication and many gene clusters. M. barkeri is distinguished by having an organization that is well conserved with respect to the other Methanosarcinae in the region proximal to the origin of replication with interspecies gene similarities as high as 95%. However it is disordered and mark… more
Date: May 19, 2006
Creator: Maeder, Dennis L.; Anderson, Iain; Brettin, Thomas S.; Bruce,David C.; Gilna, Paul; Han, Cliff S. et al.
Partner: UNT Libraries Government Documents Department
open access

Clothes washer standards in China -- The problem of water andenergy trade-offs in establishing efficiency standards

Description: Currently the sales of clothes washers in China consist ofseveral general varieties. Some use more energy (with or withoutincluding hot water energy use) and some use more water. Both energy andwater are in short supply in China. This poses the question - how do youtrade off water versus energy in establishing efficiency standards? Thispaper discusses how China dealt with this situation and how itestablished minimum efficiency standards for clothes washers.
Date: May 19, 2004
Creator: Biermayer, Peter J. & Lin, Jiang
Partner: UNT Libraries Government Documents Department
open access

3,2-HOPO Complexes of Near-Infra-Red (NIR) Emitting Lanthanides: Sensitization of Ho(III) and Pr(III) in Aqueous Solution

Description: There is a growing interest in Near Infra-Red (NIR) emission originating from organic complexes of Ln{sup III} cations. As a major impetus, biological tissues are considerably more transparent at these low energy wavelengths when compared to visible radiation, which facilitates deeper penetration of incident and emitted light. Furthermore, the long luminescence lifetimes of Ln{sup III} complexes (eg. Yb{sup III}, {tau}{sub rad} {approx} 1 ms) when compared to typical organic molecules can be ut… more
Date: May 19, 2008
Creator: Moore, Evan G.; Szigethy, Geza; Xu, Jide; Palsson, Lars-Olof; Beeby, Andrew & Raymond, Kenneth N.
Partner: UNT Libraries Government Documents Department
open access

Quantum mechanical stabilization of Minkowski signature wormholes

Description: When one attempts to construct classical wormholes in Minkowski signature Lorentzian spacetimes violations of both the weak energy hypothesis and averaged weak energy hypothesis are encountered. Since the weak energy hypothesis is experimentally known to be violated quantum mechanically, this suggests that a quantum mechanical analysis of Minkowski signature wormholes is in order. In this note I perform a minisuperspace analysis of a simple class of Minkowski signature wormholes. By solving the… more
Date: May 19, 1989
Creator: Visser, M.
Partner: UNT Libraries Government Documents Department
open access

Mirror fusion reactors. [Conceptual design studies for power plants]

Description: We have carried out conceptual design studies of fusion reactors based on the three current mirror confinement concepts: the standard mirror, the tandem mirror, and the field-reversed mirror. Recent studies of the standard mirror have emphasized its potential as a fusion-fission hybrid reactor, designed to produce fission fuel for fission reactors. We have designed a large commercial hybrid based on standard mirror confinement, and also a small pilot plant hybrid. Tandem mirror designs include … more
Date: May 19, 1978
Creator: Carlson, Gustav A. & Moir, Ralph W.
Partner: UNT Libraries Government Documents Department
open access

Diagnostics for the laser fusion program: plasma physics on the scale of microns and picoseconds

Description: Laser induced fusion is the forerunner of a class of inertial confinement schemes in which hydrogen isotopes are heated to thermonuclear conditions in a very short period. The process is characterized by such short time scales that fuel confinement is achieved through its' own finite mass and expansion velocity, approaching 1 ..mu..m/psec for ignition temperatures of order 10 keV (10/sup 8/ /sup 0/K). With current laser powers limited to several terrawatts one readily estimates, on the basis of… more
Date: May 19, 1978
Creator: Attwood, D.T.
Partner: UNT Libraries Government Documents Department
open access

Criticality parameters for tank waste evaluation

Description: Nuclear criticality parameters were developed as a basis for evaluating criticality safety for waste stored in the high-level waste tank farms on the Hanford Site in Washington State. The plutonium critical concentration and critical mass were calculated using a conservative waste model (CWM). The primary requirement of a CWM is that it have a lower neutron absorption than any actual waste. Graphs are provided of the critical mass as a function of plutonium concentration for spheres and for uni… more
Date: May 19, 1997
Creator: Rogers, C. A.
Partner: UNT Libraries Government Documents Department
open access

Older muons are wiser: Using time information in {mu}LCR spectroscopy

Description: For {mu}LCR with slow polarization transfer, the weak resonance signals can be strengthened by delaying the positron observation period, for pulsed and chopped muon beams. Furthermore, the sensitivity to drifts can be reduced or eliminated by using the ratios of late to early e{sup +} counts. These possibilities for using time information are discussed quantitatively.
Date: May 19, 1993
Creator: Leon, M.
Partner: UNT Libraries Government Documents Department
open access

A lower cost development path for heavy ion fusion

Description: If two features of the inertial fusion process are exploited successfully, they can lead to significantly lower costs for demonstrating the feasibility of commercial electric power production from this source of energy. First, fusion capsule ignition and burn physics is independent of reaction chamber size and hydrodynamically-equivalent capsules can be designed to perform at small yield, exactly as they do at large yield. This means that an integrated test of all power plant components and fea… more
Date: May 19, 1993
Creator: Hogan, W. J. & Meier, W. R.
Partner: UNT Libraries Government Documents Department
open access

NEUTRINO SCATTERING IN PERTURBATIVE QCD AND IMPLICATIONS FOR THE WEINBERG ANGLE.

Description: We summarize a recent calculation of perturbative neutrino cross sections that includes NLO and mass corrections. We provide numerical results for quantities that are related to the extraction of the weak mixing angle from neutrino deep inelastic scattering.
Date: May 19, 2003
Creator: KRETZER,S. HALL-RENO,M.
Partner: UNT Libraries Government Documents Department
open access

Density Functional Theory in Surface Chemistry and Catalysis

Description: Recent advances in the understanding of reactivity trends for chemistry at transition metal surfaces have enabled in silico design of heterogeneous catalysts in a few cases. Current status of the field is discussed with an emphasis on the role of coupling between theory and experiment and future challenges.
Date: May 19, 2011
Creator: Norskov, Jens
Partner: UNT Libraries Government Documents Department
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