Updates to the ORIGEN-S Cross-Section Libraries Using ENDF-VI, EAF-99, and FENDL-2.0 (open access)

Updates to the ORIGEN-S Cross-Section Libraries Using ENDF-VI, EAF-99, and FENDL-2.0

The standard cross-section library for light-water reactor (LWR) analyses used by the ORIGEN-S depletion and decay code has been extensively updated. This work entailed the development of broad multigroup neutron cross sections for ORIGEN-S from several sources of pointwise continuous-energy cross-section evaluations, including the U.S. Evaluated Nuclear Data Files ENDF/B-VI Release 7, the Fusion Evaluated Nuclear Data Library FENDL-2.0, and the European Activation File EAF-99. The pointwise cross sections were collapsed to a three-group structure using a continuous-energy neutron flux spectrum representative of the typical neutronic conditions of typical LWR fuel and formatted for use by ORIGEN-S. In addition, the fission-product library has been expanded to include ENDF/B-VI fission yield data for 30 fissionable actinides. The processing codes and procedures are explained. Preliminary verification studies using the updated libraries were performed using the modules of the SCALE (Standardized Computer Analyses for Licensing Evaluation) system. Comparisons between the previous basic ORIGEN-S libraries and the updated libraries developed in this work are presented.
Date: November 4, 2004
Creator: Murphy, B. D.
Object Type: Report
System: The UNT Digital Library
Reconstruction of Sedimentary Rock Based on MechanicalProperties (open access)

Reconstruction of Sedimentary Rock Based on MechanicalProperties

We describe a general, physics-based approach to numericalreconstruction of the geometrical structure and mechanical properties ofnatural sedimentary rock in 3D. Our procedure consists of three mainsteps: sedimentation, compaction, and diagenesis, followed by theverification of rock mechanical properties. The dynamic geologicprocesses of grain sedimentation and compaction are simulated by solvinga dimensionless form of Newton's equations of motion for an ensemble ofgrains. The diagenetic rock transformation is modeled using a cementationalgorithm, which accounts for the effect of rock grain size on therelative rate of cement overgrowth. Our emphasis is on unconsolidatedsand and sandstone. The main input parameters are the grain sizedistribution, the final rock porosity, the type and amount of cement andclay minerals, and grain mechanical properties: the inter-grain frictioncoefficient, the cement strength, and the grain stiffness moduli. We usea simulated 2D Fontainebleau sandstone to obtain the grain mechanicalproperties. This Fontainebleau sandstone is also used to study theinitiation, growth, and coalescence of micro-cracks under increasingvertical stress. The box fractal dimension of the micro-crackdistribution, and its variation with the applied stress areestimated.
Date: May 4, 2004
Creator: Jin, Guodong; Patzek, Tad W. & Silin, Dmitry B.
Object Type: Report
System: The UNT Digital Library
Heat Pump Water Heater Technology: Experiences of Residential Consumers and Utilities (open access)

Heat Pump Water Heater Technology: Experiences of Residential Consumers and Utilities

This paper presents a case study of the residential heat pump water heater (HPWH) market. Its principal purpose is to evaluate the extent to which the HPWH will penetrate the residential market sector, given current market trends, producer and consumer attributes, and technical parameters. The report's secondary purpose is to gather background information leading to a generic framework for conducting market analyses of technologies. This framework can be used to compare readiness and to factor attributes of market demand back into product design. This study is a rapid prototype analysis rather than a detailed case analysis. For this reason, primary data collection was limited and reliance on secondary sources was extensive. Despite having met its technical goals and having been on the market for twenty years, the HPWH has had virtually no impact on contributing to the nation's water heating. In some cases, HPWH reliability and quality control are well below market expectations, and early units developed a reputation for unreliability, especially when measured against conventional water heaters. In addition to reliability problems, first costs of HPWH units can be three to five times higher than conventional units. Without a solid, well-managed business plan, most consumers will not be drawn …
Date: August 4, 2004
Creator: Ashdown, BG
Object Type: Report
System: The UNT Digital Library
A Framework for viewing theoretical, technological, economic and market potential of carbon dioxide capture and storage (open access)

A Framework for viewing theoretical, technological, economic and market potential of carbon dioxide capture and storage

Paper presents an intelectual framework for viewing how the theoretical, technological, economic and market potentials of carbon dioxide capture and storage are related to each other.
Date: October 4, 2004
Creator: Dooley, James J.
Object Type: Report
System: The UNT Digital Library
Large plasma pressure perturbations and radial convective transport in a tokamak (open access)

Large plasma pressure perturbations and radial convective transport in a tokamak

Strongly localized plasma structures with large pressure inhomogeneities (such as plasma blobs in the scrape-off-layer (SOL)/shadow regions, pellet clouds, ELMs) observed in the tokamaks, stellarators and linear plasma devices. Experimental studies of these phenomena reveal striking similarities including more convective rather than diffusive radial plasma transport. We suggest that rather simple models can describe many essentials of blobs, ELMs, and pellet clouds dynamics. The main ingredient of these models is the effective plasma gravity caused by magnetic curvature, centrifugal or friction forces effects. As a result, the equations governing plasma transport in such localized structures appear to be rather similar to that used to describe nonlinear evolution of thermal convection in the Boussinesq approximation (directly related to the Rayleigh-Taylor instability).
Date: February 4, 2004
Creator: Krasheninnikov, S.; Ryutov, D. & Yu, G.
Object Type: Article
System: The UNT Digital Library
Seismic Response Prediction of Nupec's Field Model Tests of Npp Structures With Adjacent Building Effect. (open access)

Seismic Response Prediction of Nupec's Field Model Tests of Npp Structures With Adjacent Building Effect.

As part of a verification test program for seismic analysis computer codes for Nuclear Power Plant (NPP) structures, the Nuclear Power Engineering Corporation (NUPEC) of Japan has conducted a series of field model tests to address the dynamic cross interaction (DCI) effect on the seismic response of NPP structures built in close proximity to each other. The program provided field data to study the methodologies commonly associated with seismic analyses considering the DCI effect. As part of a collaborative program between the United States and Japan on seismic issues related to NPP applications, the U.S. Nuclear Regulatory Commission sponsored a program at Brookhaven National Laboratory (BNL) to perform independent seismic analyses which applied common analysis procedures to predict the building response to recorded earthquake events for the test models with DCI effect. In this study, two large-scale DCI test model configurations were analyzed: (1) twin reactor buildings in close proximity and (2) adjacent reactor and turbine buildings. This paper describes the NUPEC DCI test models, the BNL analysis using the SASSI 2000 program, and comparisons between the BNL analysis results and recorded field responses. To account for large variability in the soil properties, the conventional approach of computing seismic responses …
Date: March 4, 2004
Creator: Xu, J.; Hofmayer, C. & Ali, S.
Object Type: Article
System: The UNT Digital Library
Techniques in Broadband Interferometry (open access)

Techniques in Broadband Interferometry

This is a compilation of my patents issued from 1997 to 2002, generally describing interferometer techniques that modify the coherence properties of broad-bandwidth light and other waves, with applications to Doppler velocimetry, range finding, imaging and spectroscopy. Patents are tedious to read in their original form. In an effort to improve their readability I have embedded the Figures throughout the manuscript, put the Figure captions underneath the Figures, and added section headings. Otherwise I have resisted the temptation to modify the words, though I found many places which could use healthy editing. There may be minor differences with the official versions issued by the US Patent and Trademark Office, particularly in the claims sections. In my shock physics work I measured the velocities of targets impacted by flyer plates by illuminating them with laser light and analyzing the reflected light with an interferometer. Small wavelength changes caused by the target motion (Doppler effect) were converted into fringe shifts by the interferometer. Lasers having long coherence lengths were required for the illumination. While lasers are certainly bright sources, and their collimated beams are convenient to work with, they are expensive. Particularly if one needs to illuminate a wide surface area, then …
Date: January 4, 2004
Creator: Erskine, D J
Object Type: Report
System: The UNT Digital Library
Reduction of laser beam spray at 0.527 (micron)m in an ignition scale length plasma with temporal beam smoothing (open access)

Reduction of laser beam spray at 0.527 (micron)m in an ignition scale length plasma with temporal beam smoothing

We have measured the effect of laser smoothing by spectral dispersion (SSD) on beam spray, transmission and deflection of a 2{omega} (527 nm) high intensity (10{sup 15} W/cm{sup 2}) interaction beam through an underdense large scale length plasma. We observe a 40% reduction of the beam spray when SSD is used, consistent with modeling by a fluid laser-plasma interaction code (pF3d). We measured a decrease in beam transmission with increasing laser intensity, consistent with the onset of parametric instabilities.
Date: February 4, 2004
Creator: Niemann, C.; Divol, L.; Froula, D. H.; Glenzer, S. H.; Gregori, G.; Kirkwood, R. K. et al.
Object Type: Article
System: The UNT Digital Library
Improved Energy Coupling into the Gain Region of the Ni-like Pd Transient Collisional X-ray Laser (open access)

Improved Energy Coupling into the Gain Region of the Ni-like Pd Transient Collisional X-ray Laser

None
Date: October 4, 2004
Creator: Smith, R. F.; Dunn, J.; Nilsen, J.; Moon, S.; Keenan, R.; Shepherd, R. et al.
Object Type: Article
System: The UNT Digital Library
Simulating Electron Cloud Effects in Heavy-Ion Beams (open access)

Simulating Electron Cloud Effects in Heavy-Ion Beams

None
Date: June 4, 2004
Creator: Cohen, R; Friedman, A; Lund, S; Molvik, A; Azevedo, T; Vay, J et al.
Object Type: Article
System: The UNT Digital Library
Generation of Electric and Magnetic Fields During Detonation of High Explosive Charges in Boreholes (open access)

Generation of Electric and Magnetic Fields During Detonation of High Explosive Charges in Boreholes

We present experimental results of a study of electromagnetic field generation during underground detonation of high explosive charges in holes bored in sandy loam and granite. Test conditions and physico-mechanical properties of the soil exert significant influence on the parameters of electromagnetic signals generated by underground TNT charges with masses of 2 - 200 kg. The electric and magnetic field experimental data are satisfactorily described by an electric dipole model with the source embedded in a layered media.
Date: June 4, 2004
Creator: Soloviev, S. & Sweeney, J.
Object Type: Article
System: The UNT Digital Library
APDS: The Autonomous Pathogen Detection System (open access)

APDS: The Autonomous Pathogen Detection System

We have developed and tested a fully autonomous pathogen detection system (APDS) capable of continuously monitoring the environment for airborne biological threat agents. The system was developed to provide early warning to civilians in the event of a bioterrorism incident and can be used at high profile events for short-term, intensive monitoring or in major public buildings or transportation nodes for long-term monitoring. The APDS is completely automated, offering continuous aerosol sampling, in-line sample preparation fluidics, multiplexed detection and identification immunoassays, and nucleic-acid based polymerase chain reaction (PCR) amplification and detection. Highly multiplexed antibody-based and duplex nucleic acid-based assays are combined to reduce false positives to a very low level, lower reagent costs, and significantly expand the detection capabilities of this biosensor. This article provides an overview of the current design and operation of the APDS. Certain sub-components of the ADPS are described in detail, including the aerosol collector, the automated sample preparation module that performs multiplexed immunoassays with confirmatory PCR, and the data monitoring and communications system. Data obtained from an APDS that operated continuously for seven days in a major U.S. transportation hub is reported.
Date: October 4, 2004
Creator: Hindson, Benjamin; Makarewicz, Anthony; Setlur, Ujwal; Henderer, Bruce; McBride, Mary & Dzenitis, John
Object Type: Article
System: The UNT Digital Library
THE PROPERTIES AND MICROSTRUCTURE OF NB-47TI SUPERCONDUCTOR WITH MAGNETIC PINNING CENTERS. (open access)

THE PROPERTIES AND MICROSTRUCTURE OF NB-47TI SUPERCONDUCTOR WITH MAGNETIC PINNING CENTERS.

We have investigated Nb-47Ti multifilament wire with artificial pinning centers (APC). The superconducting properties and proximity effect in wires with ferromagnetic and non-magnetic pins will be discussed. Magnetization and transport measurements will be presented and the pinning characteristics will be discussed as a function of magnetic field, temperature and volume percent pins. In addition, field emission scanning electron microscopy of the pin nanostructure will be presented.
Date: February 4, 2004
Creator: MOTOWIDLO,L. R. RUDZIAK,M. D. WONG,T. COOLEY,L. D. LEE,P. J.
Object Type: Article
System: The UNT Digital Library
A multi-wavelength scattered light analysis of the dust grain population in the GG Tau circumbinary ring (open access)

A multi-wavelength scattered light analysis of the dust grain population in the GG Tau circumbinary ring

We present the first 3.8 {micro}m image of the dusty ring surrounding the young binary system GG Tau, obtained with the W. M. Keck II 10m telescope's adaptive optics system. THis is the longest wavelength at which the ring has been detected in scattered light so far, allowing a multi-wavelength analysis of the scattering proiperties of the dust grains present in this protoplanetary disk in combination with previous, shorter wavelengths, HST images. We find that the scattering phase function of the dust grains in the disk is only weakly dependent on the wavelength. This is inconsistent with dust models inferred from observations of the interstellar medium or dense molecular clouds. In particular, the strongly forward-throwing scattering phase function observed at 3.8 {micro}m implies a significant increase in the population of large ({approx}> 1 {micro}m) grains, which provides direct evidence for grain growth in the ring. However, the grain size distribution required to match the 3.8 {micro}m image of the ring is incompatible with its published 1 {micro}m polarization map, implying that the dust population is not uniform throughout the ring. We also show that our 3.8 {micro}m image of the ring is incompatible with its published 1 {micro}m polarization map, …
Date: February 4, 2004
Creator: Duchene, G; McCabe, C; Ghez, A & Macintosh, B
Object Type: Article
System: The UNT Digital Library
Results from Boiling Temperature Measurements for Saturated Solutions in the Systems NaCl + KNO{sub 3} + H{sub 2}O, NaNO{sub 3} + KNO{sub 3} + H{sub 2}O, and NaCl + NaNO{sub 3} + KNO{sub 3} + H{sub 2}O (open access)

Results from Boiling Temperature Measurements for Saturated Solutions in the Systems NaCl + KNO{sub 3} + H{sub 2}O, NaNO{sub 3} + KNO{sub 3} + H{sub 2}O, and NaCl + NaNO{sub 3} + KNO{sub 3} + H{sub 2}O

Boiling temperature measurements have been made for saturated ternary solutions of NaCl + KNO{sub 3} + H{sub 2}O and NaNO{sub 3} + KNO{sub 3} + H{sub 2}O over the full solute mole fraction range, along with the limiting binary solutions NaCl + H{sub 2}O, NaNO{sub 3} + H{sub 2}O, and KNO{sub 3} + H{sub 2}O. Boiling temperatures have also been measured for the quaternary NaCl + NaNO{sub 3} + KNO{sub 3} + H{sub 2}O mixtures with KNO{sub 3}:NaNO{sub 3} mole ratios of 1.01 and 1.19, which corresponding to the eutectic ratio and a near-eutectic ratio for the NaNO{sub 3} + KNO{sub 3} + H{sub 2}O subsystem. The maximum boiling temperature found for the NaCl + KNO{sub 3} + H{sub 2}O system is 134 C and for the NaNO{sub 3} + KNO{sub 3} + H{sub 2}O system is 160 C, but boiling temperatures as high as 196 C were measured the NaCl + NaNO{sub 3} + KNO{sub 3} + H{sub 2}O system. These mixture compositions correspond to the major mineral assemblages that are predicted to control the deliquescence relative humidity of salts found by leaching dust samples from the proposed nuclear repository at Yucca Mountain, Nevada.
Date: October 4, 2004
Creator: Rard, J A
Object Type: Report
System: The UNT Digital Library
Critical Soil-Structure Interaction Analysis Considerations for Seismic Qualification of Safety Equipment (open access)

Critical Soil-Structure Interaction Analysis Considerations for Seismic Qualification of Safety Equipment

While developing seismic analysis models for buildings that support safety-related equipment, a number of issues should be considered to ensure that the input motions for performing seismic qualification of safety-related equipment are properly defined. These considerations are listed and discussed here with special attention to the effect and importance of the interaction among the foundation soil, the building structure, the equipment anchors, and the equipment structure. Typical industry practices are critically examined to assess their adequacy for determining the input motions for equipment seismic qualification. The features that are considered essential in a soil-structure interaction (SSI) model are described. Also, the effects of inappropriate treatment or representation of these features are discussed.
Date: March 4, 2004
Creator: Hossain, Q A
Object Type: Article
System: The UNT Digital Library
Spatially Continuous Mixed P2-P1 Solutions for Planar Geometry (open access)

Spatially Continuous Mixed P2-P1 Solutions for Planar Geometry

Even-order Legendre polynomial (P{sub N}) expansion approximations of the neutron transport equation have historically seen only limited practical application. Research in the last decade has resolved one of the historical theoretical objections to the use of even-order PN approximations in planar geometry, namely the ambiguity in the prescription of boundary conditions as a result of an odd number of unknowns. This research also demonstrated the P{sub 2} approximation to be more accurate than the P{sub 1} approximation in planar geometry away from boundary layers and material interfaces. Neither the P{sub 1} nor the P{sub 2} approximation is convincingly more accurate near material interfaces. This progress motivated the reexamination of the multidimensional simplified P{sub 2} (SP{sub 2}) approximation, the development of P{sub 2} approximations for planar geometry stochastic transport problems, and the examination of the P{sub 2} and SP{sub 2} approximations as a synthetic acceleration technique for the discrete ordinates equations. The major remaining objection to even-order PN approximations is that the scalar flux distributions obtained using these approximations can exhibit large spatial discontinuities at material interfaces and source discontinuities. In contrast, the odd-order PN approximations typically utilized give spatially continuous scalar flux distributions at these locations. In this paper, we …
Date: June 4, 2004
Creator: Brantley, P S
Object Type: Article
System: The UNT Digital Library
Structure and Composition of Cu Doped CdSe Nanocrystals Using Soft X-ray Absorption Spectroscopy (open access)

Structure and Composition of Cu Doped CdSe Nanocrystals Using Soft X-ray Absorption Spectroscopy

The local structure and composition of Cu ions dispersed in CdSe nanocrystals is examined using soft x-ray absorption near edge spectroscopy (XANES). Using Cu L-edge XANES and X-ray photoelectron measurements (XPS), we find that the Cu ions exist in the Cu(I) oxidation state. We also find that the observed Cu L-edge XANES signal is directly proportional to the molar percent of Cu present in our final material. Se L-edge XANES indicates changes in the Se density of states with Cu doping, due to a chemical bonding effect, and supports a statistical doping mechanism. Photoluminescence (PL) measurements indicate the Cu ions may act as deep electron traps. We show that XANES, XPS, and PL are a powerful combination of methods to study the electronic and chemical structure of dopants in nanostructured materials.
Date: June 4, 2004
Creator: Meulenberg, R W; van Buuren, T; Hanif, K M; Willey, T M; Strouse, G F & Terminello, L J
Object Type: Article
System: The UNT Digital Library
ELMs and the H-Mode Pedestal in NSTX (open access)

ELMs and the H-Mode Pedestal in NSTX

We report on the behavior of ELMs in NBI-heated H-mode plasmas in NSTX. It is observed that the size of Type I ELMs, characterized by the change in plasma energy, decreases with increasing density, as observed at conventional aspect ratio. It is also observed that the Type I ELM size decreases as the plasma equilibrium is shifted from a symmetric double-null toward a lower single-null configuration. Type III ELMs have also been observed in NSTX, as well as a high-performance regime with small ELMs which we designate Type V. These Type V ELMs are consistent with high bootstrap current operation and density approaching Greenwald scaling. The Type V ELMs are characterized by an intermittent n=1 MHD mode rotating counter to the plasma current. Without active pumping, the density rises continuously through the Type V phase. However, efficient in-vessel pumping should allow density control, based on particle containment time estimates.
Date: June 4, 2004
Creator: Maingi, R.; Sabbagh, S.; Bush, C.; Fredrickson, E.; Menard, J.; Stutman, D. et al.
Object Type: Article
System: The UNT Digital Library
Laser Performance Operations Model (LPOM) (open access)

Laser Performance Operations Model (LPOM)

The Laser Performance Operations Model (LPOM) has been developed to provide real time predictive capabilities for the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory. LPOM uses diagnostic feedback from previous NIF shots to maintain accurate energetics models for each of the 192 NIF beamlines (utilizing one CPU per laser beamline). This model is used to determine the system setpoints (initial power, waveplate attenuations, laser diagnostic settings) required for all requested NIF shots. In addition, LPOM employs optical damage models to minimize the probability that a proposed shot may damage the system. LPOM provides post-shot diagnostic reporting to support the NIF community. LPOM was deployed prior to the first main laser shots in NIF, and has since been used to set up every shot in NIF's first quad (four beamlines). Real-time adjustments of the codes energetics parameters allows the LPOM to predict total energies within 5%, and provide energy balance within the four beamlines to within 2% for shots varying from 0.5 to 26 kJ (1.053 {micro}m) per beamline. The LPOM has been a crucial tool in the commissioning of the first quad of NIF.
Date: June 4, 2004
Creator: Shaw, M; Williams, W; House, R & Haynam, C
Object Type: Article
System: The UNT Digital Library
Identification of Minerals and Meteoritic Materials via Raman Techniques After Capture in Hypervelocity Impacts on Aerogel (open access)

Identification of Minerals and Meteoritic Materials via Raman Techniques After Capture in Hypervelocity Impacts on Aerogel

For this study, an extensive suite of mineral particles analogous to components of cosmic dust were tested to determine if their Raman signatures can be recognized after hypervelocity capture in aerogel. The mineral particles were mainly of greater than 20 micrometers in size and were accelerated onto the silica aerogel by light gas gun shots. It was found that all the individual minerals captured in aerogel could be subsequently identified using Raman (or fluorescent) spectra. The beam spot size used for the laser illumination was of the order of 5 micrometers, and in some cases the captured particles were of a similar small size. In some samples fired into aerogel there was observed a shift in the wavenumbers of some of the Raman bands, a result of the trapped particles being at quite high temperatures due to heating by the laser. Temperatures of samples under laser illumination were estimated from the relative intensities of Stokes and anti-Stokes Raman bands, or, in the case of ruby particles, from the wavenumber of fluorescence bands excited by the laser. It was found that the temperature of particles in aerogel varied greatly, dependent upon laser power and the nature of the particle. In the …
Date: October 4, 2004
Creator: Burchell, M. J.; Mann, J.; Creighton, J. A.; Kearsley, A. T.; Graham, G. A.; Esposito, A. P. et al.
Object Type: Article
System: The UNT Digital Library
Estimates of U.S. Commercial Building Electricity Intensity Trends: Issues Related to End-Use and Supply Surveys (open access)

Estimates of U.S. Commercial Building Electricity Intensity Trends: Issues Related to End-Use and Supply Surveys

This report examines measurement issues related to the amount of electricity used by the commercial sector in the U.S. and the implications for historical trends of commercial building electricity intensity (kWh/sq. ft. of floor space). The report compares two (Energy Information Administration) sources of data related to commercial buildings: the Commercial Building Energy Consumption Survey (CBECS) and the reporting by utilities of sales to commercial customers (survey Form-861). Over past two decades these sources suggest significantly different trend rates of growth of electricity intensity, with the supply (utility)-based estimate growing much faster than that based only upon the CBECS. The report undertakes various data adjustments in an attempt to rationalize the differences between these two sources. These adjustments deal with: 1) periodic reclassifications of industrial vs. commercial electricity usage at the state level and 2) the amount of electricity used by non-enclosed equipment (non-building use) that is classified as commercial electricity sales. In part, after applying these adjustments, there is a good correspondence between the two sources over the the past four CBECS (beginning with 1992). However, as yet, there is no satisfactory explanation of the differences between the two sources for longer periods that include the 1980s.
Date: September 4, 2004
Creator: Belzer, David B.
Object Type: Report
System: The UNT Digital Library
Induced polarization response of microbial induced sulfideprecipitation (open access)

Induced polarization response of microbial induced sulfideprecipitation

A laboratory scale experiment was conducted to examine the use of induced polarization and electrical conductivity to monitor microbial induced sulfide precipitation under anaerobic conditions in sand filled columns. Three columns were fabricated; one for electrical measurements, one for geochemical sampling and a third non-inoculated column was used as a control. A continual upward flow of nutrients and metals in solution was established in each column. Desulfovibrio vulgaris microbes were injected into the middle of the geochemical and electrical columns. Iron and zinc sulfides precipitated along a microbial action front as a result of sulfate reduction due by Desulfovibrio vulgaris. The precipitation front initially developed near the microbial injection location, and subsequently migrated towards the nutrient inlet, as a result of chemotaxis by Desulfovibrio vulgaris. Sampling during and subsequent to the experiment revealed spatiotemporal changes in the biogeochemical measurements associated with microbial sulfate reduction. Conductivity measurements were insensitive to all biogeochemical changes occurred within the column. Changes in the IP response (of up to 14 mrad)were observed to coincide in place and in time with the active microbe respiration/sulfide precipitation front as determined from geochemical sampling. The IP response is correlated with the lactate concentration gradient, an indirect measurement of …
Date: June 4, 2004
Creator: Ntarlagiannis, Dimitrios; Williams, Kenneth Hurst; Slater, Lee & Hubbard, Susan
Object Type: Article
System: The UNT Digital Library
Magnetization reversal behaviour of nanogranular CoCrPt alloy thinfilms studied with magnetic transmission X-ray microscopy (open access)

Magnetization reversal behaviour of nanogranular CoCrPt alloy thinfilms studied with magnetic transmission X-ray microscopy

The angular dependence of dissociative electron attachment (DEA) to polyatomic targets is formulated in the local complex potential model, under the assumption that the axial recoil approximation describes the dissociation dynamics. An additional approximation, which is found to be valid in the case of H{sub 2}O but not in the case of H{sub 2}S, makes it possible to describe the angular dependence of DEA solely from an analysis of the fixed-nuclei entrance amplitude, without carrying out nuclear dynamics calculations. For H{sub 2}S, the final-vibrational-state-specific angular dependence of DEA is obtained by incorporating the variation of the angular dependence of the entrance amplitude with nuclear geometry into the nuclear dynamics. Scattering calculations using the complex Kohn method and, for H{sub 2}S, full quantum calculations of the nuclear dynamics using the Multi-Configuration Time-Dependent Hartree method, are performed.
Date: November 4, 2004
Creator: Fischer, P.; Im, M.-Y.; Eimuller, T.; Schutz, G. & Shin, S.-C.
Object Type: Article
System: The UNT Digital Library