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Cosmological moduli problem in a supersymmetric model with direct gauge mediation

Description: Recently, an interesting class of the direct gauge mediation supersymmetry (SUSY) breaking models are proposed, in which the minimum of the potential of the SUSY breaking field is determined by the inverted hierarchy mechanism. We consider their cosmological implications. In this class of models, SUSY breaking field has a very flat potential, which may have a cosmological importance. Assuming the initial amplitude of the SUSY breaking field to be of the order of the Planck scale, it can be a so… more
Date: July 7, 1998
Creator: Moroi, Takeo
Partner: UNT Libraries Government Documents Department
open access

Mongolia wind resource assessment project

Description: The development of detailed, regional wind-resource distributions and other pertinent wind resource characteristics (e.g., assessment maps and reliable estimates of seasonal, diurnal, and directional) is an important step in planning and accelerating the deployment of wind energy systems. This paper summarizes the approach and methods being used to conduct a wind energy resource assessment of Mongolia. The primary goals of this project are to develop a comprehensive wind energy resource atlas o… more
Date: September 7, 1998
Creator: Elliott, D.; Chadraa, B. & Natsagdorj, L.
Partner: UNT Libraries Government Documents Department
open access

Transuranic separation using organophophorus extractants adsorbed onto superparamagnetic carriers.

Description: Polymeric coated ferromagnetic carriers with an absorbed layer of octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) diluted by tributyl phosphate (TBP) are being evaluated for application in the separation and the recovery of low concentrations of americium, plutonium, and uranium from nuclear waste solutions. Due to their chemical nature, these extractants selectively complex americium and plutonium contaminants onto the particles and the complexed particles can be recovered fr… more
Date: October 7, 1998
Creator: Nunez, L.
Partner: UNT Libraries Government Documents Department
open access

Imprinted spiral structures as neutron polarizers.

Description: Neutron diffraction from magnetic spiral structures is governed by strong selection rules for the polarization of the outgoing beam. When the sample is entirely of one chirality--for instance a right handed spiral--the neutrons diffracted by some Bragg reflections are fully polarized. While the scattering theory has been formulated long ago, attempts to controllably modify the population of left handed and right handed spiral domains in natural magnetic structures (which for instance occur in s… more
Date: October 7, 1998
Creator: Lohstroh, W.
Partner: UNT Libraries Government Documents Department
open access

Recent developments pertinent to processing of ENDF/B-6 type resonance cross section data.

Description: In view of our increasing dependence on computations rather than construction and operation of more costly experimental facilities, the rigor and accuracy achievable by calculational methods certainly deserve more attention. This is particularly so for the Monte Carlo methods which are generally regarded as the ultimate computational standard for the entire nuclear community around the globe. One obvious question that one may raise is whether the numerical algorithms deployed to process cross s… more
Date: July 7, 1998
Creator: Hwang, R. N.
Partner: UNT Libraries Government Documents Department
open access

What causes Psi suppression in Pb + Pb Collisions?

Description: A reexamination of hadronic comover scattering indicates that this mechanism cannot explain the observed {psi} suppression in Pb+Pb interactions. The possibility of quark-gluon plasma formation is therefore considered. Implications for RHIC and LHC are also discussed. The agreement of the NA50 Pb+Pb data with naive comover models is reassessed. Previous work is reanalyzed and expanded to include feeding of the {psi}' and {chi}{sub c} states to the {psi}. The effect of color screening is also in… more
Date: January 7, 1998
Creator: Vogt, R.
Partner: UNT Libraries Government Documents Department
open access

Performance and Modeling of Amorphous Silicon Photovoltaics for Building-Integrated Applications (Preprint prepared for Solar 99)

Description: Amorphous silicon photovoltaic (PV) modules offer several advantages for building-integrated applications. The material can be deposited on glass or flexible substrates, which allows for products like roofing shingles and integrated PV/building glass. The material also has a uniform surface, which is ideal for many architectural applications. Amorphous silicon modules perform well in warm weather and have a small temperature coefficient for power. Depending on the building load, this may be ben… more
Date: June 7, 1998
Creator: Kroposki, B. & Hansen, R.
Partner: UNT Libraries Government Documents Department
open access

Cosmic Closure: Relating the Ultimate Fate of Massive Stars and the Ultimate Fate of the Universe

Description: We give a brief overview of the status of core collapse supernova modeling, particularly as it pertains to predictions of neutrino signatures for the next galactic or near extragalactic supernova. We also consider the implications of neutrino mass for both the supernova mechanism and neutrino signature predictions.
Date: September 7, 1998
Creator: Bruenn, S.W. & Mezzacappa, A.
Partner: UNT Libraries Government Documents Department
open access

Parameter identification and on-line estimation for reduced kinetic model

Description: The base hydrolysis process for the destruction of energetic or explosive materials results is a high pH hydrolysate solution with reaction products that include a series of carboxylic acid salts, glycolates, amines, and nitrates. The hydrolysate solutions obtained from this process contain from two to ten wt% of organic carbon and nitrogen compounds that must be further treated before disposal. Hydrothermal oxidation at elevated temperatures (450 C) and pressure (14,000 psi) was selected as th… more
Date: August 7, 1998
Creator: Littel, J. D.; Muske, K. R.; Del`Orco, P. C.; Le, L. A. & Flesner, R. L.
Partner: UNT Libraries Government Documents Department
open access

Vitrification of Simulated Fernald K-65 Silo Waste at Low Temperature

Description: Vitrification is the technology that has been chosen to solidify approximately 18,000 tons of geologic mill tailings, designated as K-65 wastes, at the Fernald Environmental Management Project (FEMP) in Fernald, Ohio. The glass formula developed in this study for the FEMP wastes is a lithia substituted soda-lime-lithia-silica (SLLS) composition which melts at 1050 degrees Celsius. Low melting formulations minimize volatilization of hazardous species such as arsenic, selenium, chromium, and lead… more
Date: July 7, 1998
Creator: Jantzen, Carol M. & Pickett, J. B.
Partner: UNT Libraries Government Documents Department
open access

Parallel Strategies for Crash and Impact Simulations

Description: We describe a general strategy we have found effective for parallelizing solid mechanics simula- tions. Such simulations often have several computationally intensive parts, including finite element integration, detection of material contacts, and particle interaction if smoothed particle hydrody- namics is used to model highly deforming materials. The need to balance all of these computations simultaneously is a difficult challenge that has kept many commercial and government codes from being u… more
Date: December 7, 1998
Creator: Attaway, S.; Brown, K.; Hendrickson, B. & Plimpton, S.
Partner: UNT Libraries Government Documents Department
open access

Generation of Chloride Active Defects at the Aluminum Oxide Surface for the Study of Localized Corrosion Initiation

Description: The generation of surface defects on electron cyclotron resonance (ECR) plasma derived aluminum oxide films has been studied. We find that Cl active O vacancies can be generated using electron and ion irradiation yielding surface concentrations of 3 xl 013 to 1X1014 sites"cm-2. These values correspond to surface defect concentrations of 3 to 10% when compared to ordered, crystalline u-alumina. The vacancies appear to be responsible for increased surface O concentrations when immersed in water. … more
Date: December 7, 1998
Creator: Barbour, J.C.; Missert, N.; Son, K.-A; Wall, F.D. & Zavadil, K.R.
Partner: UNT Libraries Government Documents Department
open access

Novel transport-vehicle design for moving optic modules in the National Ignition Facility

Description: The National Ignition Facility, currently under design and construction at Lawrence Livermore National Laboratory, will be the world`s largest laser when complete. The NIF will use about 8,000 large optics of 26 different types to focus up to 192 laser beams on a dime-size target. Given the constraints of the NIF operating environment, the tasks associated with optics transport and handling require a novel, versatile transport system. The system will consist of a computer system containing guid… more
Date: May 7, 1998
Creator: Grasz, E. & Tiszauer, D.
Partner: UNT Libraries Government Documents Department
open access

Self-Irradiation Effects on 99Mo Reagents and Products

Description: produced in 1996 and shipped to pharmaceutical houses for evaluation of compatibility with oxime solution used to precipitate `?vfo as the oxime complex is both air and light-sensitive, and containing a black precipitate that forms during shipment, presumably as a result of self- irradiation. Addition of sodium hypochlorite to the product solution prior to shipment prevents precipitate formation, indicating the precipitate is a reduced form of `%lo. to remove any precipitate. Duplicate aliquots… more
Date: October 7, 1998
Creator: Carson, S. D.; Garcia, M. J.; McDonald, M. J.; Simpson, R. L. & Tallant, D. R.
Partner: UNT Libraries Government Documents Department
open access

Electronic excitation in transmission of relativistic H{sup {minus}} ions through thin foils

Description: The authors describe a theoretical model to study the transmission of relativistic H{sup {minus}} ions through thin carbon foils. The approach is based on a Monte Carlo solution of the Langevin equation describing electronic excitations of the atoms during the transport through the foil. Calculations for the subshell populations of outgoing hydrogen atoms are found to be in good agreement with recent experimental data on an absolute scale and show that there exists a propensity for populating e… more
Date: May 7, 1998
Creator: Reinhold, C.O.; Kuerpick, P.; Burgdoerfer, J.; Yoshida, S. & Gervais, B.
Partner: UNT Libraries Government Documents Department
open access

Modeling A.C. Electronic Transport through a Two-Dimensional Quantum Point Contact

Description: We present the results on the a.c. transport of electrons moving through a two-dimensional (2D) semiconductor quantum point contact (QPC). We concentrate our attention on the characteristic properties of the high frequency admittance ({omega}{approximately}0 - 50 GHz), and on the oscillations of the admittance in the vicinity of the separatrix (when a channel opens or closes), in presence of the relaxation effects. The experimental verification of such oscillations in the admittance would be a … more
Date: December 7, 1998
Creator: Aronov, I. E.; Beletskii, N. N.; Berman, G. P.; Campbell, D. K.; Doolen, G. D. & Dudiy, S. V.
Partner: UNT Libraries Government Documents Department
open access

Electron-Nuclear Spin Dynamics in a Mesoscopic Solid-State Quantum Computer

Description: We numerically simulate the process of nuclear spin measurement in Kane's quantum computer. For this purpose, we model the quantum dynamics of two coupled nuclear spins located on {sup 31}P donors implanted in Si. We estimate the minimum time of measurement necessary for the reliable transfer of quantum information from the nuclear spin subsystem to the electronic one and the probability of error for typical values of external noise.
Date: December 7, 1998
Creator: Berman, G. P.; Campbell, D. K.; Doolen, G. D. & Nagaev, K. E.
Partner: UNT Libraries Government Documents Department
open access

High-Damage-Threshold Pinhole for Glass Fusion Laser Applications

Description: We are investigating methods to fabricate high-damage-threshold spatial-filter pinholes that might not be susceptible to plasma closure for relatively high energies and long pulses. These are based on the observation that grazing-incidence reflection from glass can withstand in excess of 5 kJ/cm{sup 2} (normal to the beam) without plasma formation. The high damage threshold results from both the cos q spreading of the energy across the surface and the reflection of a large fraction of the energ… more
Date: June 7, 1998
Creator: Kumit, N. A.; Letzring, S. A. & Johnson, R. P.
Partner: UNT Libraries Government Documents Department
open access

Multiscale Modeling of Recrystallization

Description: We propose a multi length scale approach to modeling recrystallization which links a dislocation model, a cell growth model and a macroscopic model. Although this methodology and linking framework will be applied to recrystallization, it is also applicable to other types of phase transformations in bulk and layered materials. Critical processes such as the dislocation structure evolution, nucleation, the evolution of crystal orientations into a preferred texture, and grain size evolution all op… more
Date: December 7, 1998
Creator: Godfrey, A. W.; Holm, E. A.; Hughes, D. A.; Lesar, R. & Miodownik, M. A.
Partner: UNT Libraries Government Documents Department
open access

National Laboratories and Internatioanl Partnering

Description: For nearly fifty years the US held a dominant position in research and development in the free world. The situation has changed dramatically in the last decade. Countries around the world realize that to foster sustainable economic growth, they must build and maintain a foundation in science and technology. The time in which a country could base its gross national product solely on extraction of raw materials or on people-intensive manufacturing is drawing to a close. The funding for research a… more
Date: December 7, 1998
Creator: Eagan, R. J.; Gauster, W. B.; Hartley, D. L. & Jones, G. J.
Partner: UNT Libraries Government Documents Department
open access

Identification of mine collapses, explosions and earthquakes using INSAR: a preliminary investigation

Description: Interferograms constmcted from satellite-borne synthetic aperture radar images have the capability of mapping sub-cm ground surface deformation over areas on the order of 100 x 100 km with a spatial resolution on the order of 10 meters. We investigate the utility of synthetic aperture radar interferomehy (InSAR) used in conjunction with regional seismic methods in detecting and discriminating different types of seismic events in the context of special event analysis for the CTBT. For this initi… more
Date: July 7, 1998
Creator: Foxall, B.; Sweeney, J. J. & Walter, W. R.
Partner: UNT Libraries Government Documents Department
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