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3-D Combinatorial Geometry in the MERCURY Monte Carlo Particle Transport Code

Description: Lawrence Livermore National Laboratory is in the process of developing a new Monte Carlo Particle Transport code named MERCURY. This new code features a 3-D Combinatorial Geometry tracking algorithm. This paper details some of the characteristics of this Monte Carlo tracker
Date: September 27, 2004
Creator: Greenman, G
Partner: UNT Libraries Government Documents Department
open access

3-D Simulations of Plasma Wakefield Acceleration with Non-Idealized Plasmas and Beams

Description: 3-D Particle-in-cell OSIRIS simulations of the current E-162 Plasma Wakefield Accelerator Experiment are presented in which a number of non-ideal conditions are modeled simultaneously. These include tilts on the beam in both planes, asymmetric beam emittance, beam energy spread and plasma inhomogeneities both longitudinally and transverse to the beam axis. The relative importance of the non-ideal conditions is discussed and a worst case estimate of the effect of these on energy gain is obtained… more
Date: September 27, 2005
Creator: Deng, S.; Katsouleas, T.; Lee, S.; Muggli, P.; Mori, W. B.; Hemker, R. et al.
Partner: UNT Libraries Government Documents Department
open access

Aging of Polyurethane Foam Insulation in Simulated Refrigerator Panels--One-Year Results with Third-Generation Blowing Agents

Description: Laboratory data are presented on the effect of constant-temperature aging on the apparent thermal conductivity of polyurethane foam insulation for refrigerators and freezers. The foam specimens were blown with HCFC-141b and with three of its potential replacements--HFC-134a, HFC-245fa, and cyclopentane. Specimens were aged at constant temperatures of 90 F, 40 F, and {minus}10 F. Thermal conductivity measurements were made on two types of specimens: full-thickness simulated refrigerator panels c… more
Date: September 27, 1999
Creator: Gabbard, W. A.; Weaver, F. J. & Wilkes, K. E.
Partner: UNT Libraries Government Documents Department
open access

Alterative LEU designs for the FRM-II with power levels of 20-22 MW.

Description: Alternative LEU Designs for the FRM-II have been developed by the RERTR Program at Argonne National Laboratory (ANL) at the request of an FRM-II Expert Group established by the German Federal Government in January 1999 to evaluate the options for using LEU fuel instead of HEU fuel in cores with power levels of 20 MW. The ANL designs would use the same building structure and maintain as many of the HEU design features as practical. The range of potential LEU fuels was expanded from previous stud… more
Date: September 27, 1999
Creator: Hanan, N. A.; Smith, R. S. & Matos, J. E.
Partner: UNT Libraries Government Documents Department
open access

Anisotropic Optical Properties of 2D Silicon Telluride

Description: Article reports an ab initio computational study of the optical dielectric properties of Silicon telluride (Si2Te3) using the GW approximation and the Bethe-Salpeter equation (BSE).
Date: September 27, 2020
Creator: Cui, Jingbiao; Bhattarai, Romakanta; Chen, Jiyang; Hoang, Thang B. & Shen, Xiao
Partner: UNT College of Science
open access

Application of Various Normalization Methods for Microscale Analysis of Tissues Using Direct Analyte Probed Nanoextraction

Description: Article describes a study where various normalization techniques were investigated in order to improve the quantitative capabilities of direct analyte probed nanoextraction (DAPNe).
Date: September 27, 2018
Creator: de Jesus, Janella; Bunch, Josephine; Verbeck, Guido F.; Webb, Roger P.; Costa, Catia; Goodwin, Richard J. A. et al.
Partner: UNT College of Science
open access

Argonne's atlas control system upgrade.

Description: The ATLAS facility (Argonne Tandem-Linac Accelerator System) is located at the Argonne National Laboratory. The facility is a tool used in nuclear and atomic physics research, which focuses primarily on heavy-ion physics. The accelerator as well as its control system are evolutionary in nature, and consequently, continue to advance. In 1998 the most recent project to upgrade the ATLAS control system was completed. This paper briefly reviews the upgrade, and summarizes the configuration and feat… more
Date: September 27, 1999
Creator: Munson, F.; Quock, D.; Chapin, B. & Figueroa, J.
Partner: UNT Libraries Government Documents Department
open access

Asymptotic Analysis of Time-Dependent Neutron Transport Coupled with Isotopic Depletion and Radioactive Decay

Description: We describe an asymptotic analysis of the coupled nonlinear system of equations describing time-dependent three-dimensional monoenergetic neutron transport and isotopic depletion and radioactive decay. The classic asymptotic diffusion scaling of Larsen and Keller [1], along with a consistent small scaling of the terms describing the radioactive decay of isotopes, is applied to this coupled nonlinear system of equations in a medium of specified initial isotopic composition. The analysis demonstr… more
Date: September 27, 2006
Creator: Brantley, P S
Partner: UNT Libraries Government Documents Department
open access

An automated computer misuse detection system for UNICOS

Description: An effective method for detecting computer misuse is the automatic monitoring and analysis of on-line user activity. This activity is reflected in the system audit record, in the system vulnerability posture, and in other evidence found through active testing of the system. During the last several years we have implemented an automatic misuse detection system at Los Alamos. This is the Network Anomaly Detection and Intrusion Reporter (NADIR). We are currently expanding NADIR to include processi… more
Date: September 27, 1994
Creator: Jackson, K. A.; Neuman, M. C.; Simmonds, D. D.; Stallings, C. A.; Thompson, J. L. & Christoph, G. G.
Partner: UNT Libraries Government Documents Department
open access

Automatic Scheme Selection for Toolkit Hex Meshing

Description: Current hexahedral mesh generation techniques rely on a set of meshing tools, which when combined with geometry decomposition leads to an adequate mesh generation process. Of these tools, sweeping tends to be the workhorse algorithm, accounting for at least 50% of most meshing applications. Constraints which must be met for a volume to be sweepable are derived, and it is proven that these constraints are necessary but not sufficient conditions for sweepability. This paper also describes a new a… more
Date: September 27, 1999
Creator: TAUTGES,TIMOTHY J. & WHITE,DAVID R.
Partner: UNT Libraries Government Documents Department
open access

Bayesian Prior Choice in IRT Estimation Using MCMC and Variational Bayes

Description: This study investigates the impact of three prior distributions: matched, standard vague, and hierarchical in Bayesian estimation parameter recovery in two and one parameter models.
Date: September 27, 2016
Creator: Natesan, Prathiba; Nandakumar, Ratna; Minka, Tom & Rubright, Jonathan D.
Partner: UNT College of Education
open access

Benchmark Calculation Of Inclusive Responses In The Four-Body Nuclear System

Description: This paper reports on a recent benchmark calculation in the four-nucleon system, aimed at investigating the reliability of the no-core shell model (NCSM) approach to the description of inclusive response functions via the Lorentz integral transform (LIT) method.
Date: September 27, 2006
Creator: Quaglioni, S.; Stetcu, I.; Bacca, S.; Barrett, B. R.; Johnson, C. W.; Navratil, P. et al.
Partner: UNT Libraries Government Documents Department
open access

Chemistry Surrounding Monomeric Copper(l) Methyl, Phenyl, Anilido, Ethoxide, and Phenoxide Complexes Supported by N-Heterocyclic Carbene Ligands: Reactivity Consistent with Both Early and Late Transition Metal Systems

Description: Article on chemistry surrounding monomeric copper(I) methyl, phenyl, anilido, ethoxide, and phenoxide complexes supported by N-heterocyclic carbene ligands.
Date: September 27, 2006
Creator: Goj, Laurel A.; Blue, Elizabeth D.; Delp, Samuel A.; Gunnoe, T. Brent; Cundari, Thomas R., 1964-; Pierpont, Aaron W. et al.
Partner: UNT College of Arts and Sciences
open access

Coherent Instabilities of ILC Damping Ring

Description: The paper presents the first attempt to estimates the ILC damping ring impedance and compare thresholds of the classical instabilities for several designs initially proposed for the DR. The work was carried out in the spring of 2006. Since then the choice of the DR is narrowed. Nevertheless, the analysis described may be useful for the next iterations of the beam stability. Overall, the conventional instabilities will have little impact on the ring performance provided the careful design of the… more
Date: September 27, 2006
Creator: Heifets, S.; Stupakov, G. & Bane, K.
Partner: UNT Libraries Government Documents Department
open access

Comment on "The shape and composition of interstellar silicate grains"

Description: In the paper entitled 'The shape and composition of interstellar silicate grains' (A & A, 462, 667-676 (2007)), Min et al. explore non-spherical grain shape and composition in modeling the interstellar 10 and 20 {micro}m extinction features. This progression towards more realistic models is vitally important to enabling valid comparisons between dust observations and laboratory measurements. Min et al. proceed to compare their model results with GEMS (glass with embedded metals and sulfides) fr… more
Date: September 27, 2007
Creator: Bradley, J P & Ishii, H
Partner: UNT Libraries Government Documents Department
open access

A complete analytic inversion of supernova lines in the Sobolevapproximation

Description: We show that the shape of P-Cygni line profiles of photospheric phase supernova can be analytically inverted to extract both the optical depth and source function of the line -- i.e. all the physical content of the model for the case when the Sobolev approximation is valid. Under various simplifying assumptions, we derive formulae that give S(r) and {tau}(r) in terms of derivatives of the line flux with respect to wavelength. The transition region between the minimum and maximum of the line pro… more
Date: September 27, 2001
Creator: Kasen, Daniel; Branch, David; Baron, E. & Jeffery, David
Partner: UNT Libraries Government Documents Department
open access

Computer-controlled radiation monitoring system

Description: A computer-controlled radiation monitoring system was designed and installed at the Lawrence Livermore National Laboratory`s Multiuser Tandem Laboratory (10 MV tandem accelerator from High Voltage Engineering Corporation). The system continuously monitors the photon and neutron radiation environment associated with the facility and automatically suspends accelerator operation if preset radiation levels are exceeded. The system has proved reliable real-time radiation monitoring over the past fiv… more
Date: September 27, 1994
Creator: Homann, S.G.
Partner: UNT Libraries Government Documents Department
open access

Controlling the electronic structure of nanocrystal assemblies by variation of the particle - particle interaction

Description: The change in the electronic structure of germanium nanocrystals is investigated as their concentration is increased from non-interacting, individual particles to assembled arrays of particles. The electronic structure of the individual nanoclusters shows clear effects due to quantum confinement which are lost in the concentrated assemblies of bare particles. When the surface of the individual particles is passivated, they retain their quantum confinement properties also upon assembly. These ef… more
Date: September 27, 2004
Creator: Bostedt, C; van Buuren, T; Willey, T M & Terminello, L J
Partner: UNT Libraries Government Documents Department
open access

Corrosion mechanisms of spent fuel under oxidizing conditions

Description: The release of {sup 99}Tc can be used as a reliable marker for the extent of spent oxide fuel reaction under unsaturated high-drip-rate conditions at 90{degrees}C. Evidence from leachate data and from scanning and transmission electron microscopy (SEM and TEM) examination of reacted fuel samples is presented for radionuclide release, potential reaction pathways, and the formation of alteration products. In the ATM-103 fuel, 0.03 of the total inventory of {sup 99}Tc is released in 3.7 years unde… more
Date: September 27, 1997
Creator: Finn, P.A.; Finch, R.; Buck, E. & Bates, J.
Partner: UNT Libraries Government Documents Department
open access

Coupled 3D reactor kinetics and thermal-hydraulic code development activities at the U.S. Nuclear Regulatory Commission

Description: The USNRC version of the 3D neutron kinetics code, Purdue Advanced Reactor Core Simulator (PARCS), has been coupled to the USNRC thermal-hydraulic (T/H) codes RELAP5 and the consolidated TRAC (merger of TRAC-BF1 and TRAC-PF1). These coupled codes may be used to audit license safety analysis submittals where 3D spatial kinetics and thermal-hydraulic effects are important. The coupling scheme was designed and implemented with emphasis placed on maximizing flexibility while minimizing modification… more
Date: September 27, 1999
Creator: Barber, D.; Miller, R.M.; Joo, H.; Downar, T.; Wang, W. & Mousseau, V.
Partner: UNT Libraries Government Documents Department
open access

Cryogenic Field Measurement of Pr2Fe14B Undulator and Performance Enhancement Options at the NSLS-II

Description: Short period (14.5mm) hybrid undulator arrays composed of Praseodymium Iron Boron (Pr{sub 2}Fe{sub 14}B) magnets (CR53, NEOMAX, Inc.) and vanadium permendur poles have been fabricated at Brookhaven National Laboratory. Unlike Neodymium Iron Boron (Nd{sub 2}Fe{sub 14}B) magnets which exhibit spin reorientation at temperatures below 150K, PrFeB arrays monotonically increase performance with lower operating temperature. It opens up the posibility for use in operating a cryo-permanent magnet undula… more
Date: September 27, 2009
Creator: Tanabe, T.; Chubar, O.; Harder, David A.; Lehecka, Michael; Rank, James; Rakowsky, George et al.
Partner: UNT Libraries Government Documents Department
open access

Descriptive Complexity in Cantor Series

Description: Article discusses how a Cantor series expansion for a real number x with respect to a basic sequence Q=(q), where qi≥2, is a generalization of the base b expansion to an infinite sequence of bases. The authors show that for any basic sequence the set of distribution normal numbers is Π03-complete, and if Q is 1-divergent then the sets of normal and ratio normal numbers are Π03-complete.
Date: September 27, 2021
Creator: Airey, Dylan; Jackson, Steve & Mance, Bill
Partner: UNT College of Science
open access

Design of an electrostatic end-plugged plasma-confinement device

Description: A laboratory-scale experimental device having an outside diameter of 1.2 m has been designed to test the idea of electrostatic end plugging of an open-ended magnetic-field configuration. The configuration is a toroidal quadrupole having four very thin (less than 1-mm-thick) line cusps produced by four circular copper coils. Iron is used to concentrate the magnetic flux density to 2.0 T; without the use of iron, the power consumption, which is about 1 MW, would be about 25 times higher. The use … more
Date: September 27, 1977
Creator: Moir, R.W.; Dolan, T.J. & Barr, W.L.
Partner: UNT Libraries Government Documents Department
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