Decay of /sup 99/Mo (open access)

Decay of /sup 99/Mo

Relative intensities for K x-rays and gamma rays emanating from /sup 99/Mo in equilibrium with its /sup 99/Tc* daughter have been measured using several Ge photon detectors. Combining these intensities with an evaluated set of electron-conversion coefficients has provided a set of absolute intensities for the observed gamma rays. The absolute intensity for the dominant 140.5-keV gamma ray in /sup 99/Tc was determined to be 90.7 +- 0.6/100 /sup 99/Mo disintegrations for /sup 99/Mo decay in equilibrium with decay of the /sup 99/Tc* daughter.
Date: December 14, 1976
Creator: Dickens, J. K. & Love, T. A.
Object Type: Report
System: The UNT Digital Library
Equation of state and shock entropy of CaCO/sub 3/ (open access)

Equation of state and shock entropy of CaCO/sub 3/

The energy released in a nuclear detonation can vaporize the surrounding medium. If one knows the gaseous equation of state of the medium, it can be used along with estimates of the shock entropy to predict such things as cavity size and seismic effects. We have calculated the equation of state and shock entropy for calcite (CaCO/sub 3/). We formulated the gaseous equation of state for pressures between 1 and 10/sup 6/ bar and temperatures from ambient to 1000 eV using a combination of the TIGER and IEEOS codes. In this report, we also describe the calculational methods and the material parameters used to estimate shock entropy on the loading path. We show how these results can be used to estimate final states following unloading from a given point on the shock Hugoniot. A specific example, dense calcite at 900 kbar, is used to illustrate the method.
Date: December 14, 1976
Creator: Pasternak, A.; Lee, E. L. & Miller, D. G.
Object Type: Report
System: The UNT Digital Library
Waveguide Fabrication in Fused Silica Using Tightly Focused Femtosecond Laser Pulses (open access)

Waveguide Fabrication in Fused Silica Using Tightly Focused Femtosecond Laser Pulses

Refractive index changes have been induced inside bulk fused silica by using femtosecond (fs) laser pulses tightly focused inside the material. Waveguides have been fabricated inside the glass by scanning the glass with respect to the focal point of the laser beam. The refractive index change is estimated to be {approx} 10{sup -4}. Other more complex three-dimensional structures have also been fabricated (curved waveguides, splitters, and interferometers). We also report on fluorescence spectroscopy of the fs-modified fused silica using a confocal microscopy setup. Using a 488 nm excitation source, a fluorescence at 630 nm is observed from the modified glass, which is attributed to the presence of non-bridging oxygen hole center (NBOHC) defects created by the fs pulses. The fluorescence decays with prolonged exposure to the 488 nm light, indicating that the defects are being photobleached by the excitation light.
Date: December 14, 2001
Creator: Chan, J W; Huser, T; Risbud, S H & Krol, D M
Object Type: Article
System: The UNT Digital Library
Investigating the Heating of a Potassium-Doped Aluminosilicate Ion Source Using a 1 Micron Laser (open access)

Investigating the Heating of a Potassium-Doped Aluminosilicate Ion Source Using a 1 Micron Laser

The heavy ion fusion (HIF) program is interested in developing a high brightness ion source for high energy density physics (HEDP) experiments. One possible approach to obtaining higher brightness may be to raise the surface temperature of the ion source just prior to extraction. The current ion source material being studied is a layer of potassium-doped aluminosilicate bonded to a tungsten substrate. It is speculated that if the surface temperature of the source is raised above 1200 C (from a steady-state temperature of 900 C) for time periods on the order of 100's of nanoseconds, current densities of greater than 100 mA/cm{sup 2} of ions may be achievable. Typical aluminosilicate sources produce ion current densities (either K+ or Na+ ions) of {approx}10 mA/cm{sup 2} (at 1100 C). A number of heating methods might be possible, including lasers, diode arrays, and flash lamps. Here we assume laser heating. In this preliminary study, we used the LLNL RadHeat code to model the time-temperature history of the surface when hit by laser pulses and illustrate how RadHeat can be used to optimize the surface temperature response. Also of interest is the temperature history of the interface temperature between the ceramic and the metal …
Date: December 14, 2004
Creator: Schmitt, R. C.; Meier, W. R.; Kwan, J. W.; Abbott, R. P. & Latkowski, J. F.
Object Type: Report
System: The UNT Digital Library
Surface Based Differential Forms (open access)

Surface Based Differential Forms

Higher-order basis functions have been constructed for surface-based differential forms that are used in engineering simulations. These surface-based forms have been designed to complement the volume-based forms present in EMSolve[1], a finite element code. The basis functions are constructed on a reference element and transformed, as necessary, for each element in space. Lagrange polynomials are used to create the basis functions. This approach is a necessary step in creating a hybrid finite-element/integral-equation time-domain code for electromagnetic analysis.
Date: December 14, 2004
Creator: Pingenot, J.; Yang, C.; Jandhyala, V.; Champagne, N.; White, D.; Stowell, M. et al.
Object Type: Article
System: The UNT Digital Library
High-efficiency diffractive x-ray optics from sectioned multilayers (open access)

High-efficiency diffractive x-ray optics from sectioned multilayers

We investigate the diffraction properties of sectioned multilayers in Laue (transmission) geometry, at hard x-ray energies (9.5 and 19.5 keV). Two samples are studied, a 200 period W/Si multilayer of 29 nm d-spacing, and a 2020 period Mo/Si multilayer of 7 nm d-spacing, with cross-section depths ranging from 2 to 17 {micro}m. Rocking curves across the Bragg reflections exhibit well-defined interference fringes originating from the depth of the sample. Efficiencies as high as 70% were obtained. This exceeds the theoretical limit for standard zone plates operating in the multi-beam regime, demonstrating that all of the intensity can be directed into a single diffraction order in small-period structures.
Date: December 14, 2004
Creator: Kang, H. C.; Stephenson, G. B.; Liu, C.; Conley, R.; Macrander, A. T.; Maser, J. et al.
Object Type: Article
System: The UNT Digital Library
Experimental assessment of gradient plasticity (open access)

Experimental assessment of gradient plasticity

Classical plasticity theories generally assume that the stress at a point is a function of strain at that point only. However, when gradients in strain become significant, this localization assumption is no longer valid. A common factor in the failure of these conventional models is that, since they do not account for the strain gradients, they do not display a size effect. This effect is seen experimentally when the scale of the phenomenon of interest is on the order of several microns. At this scale, strain gradients are of a significant magnitude as compared to the overall strain and must be considered for models to accurately capture observed phenomena. The mechanics community has been actively involved in the development of strain gradient theories for many years. Recently, interest in this area has been rekindled and several new approaches have appeared in the literature. Two different approaches are currently being evaluated: one approach considers strain gradients as internal variables which do not introduce work conjugate higher order stresses, and another approach considers the strain gradients as internal degrees of freedom which requires work conjugate higher order stresses. Experiments are being performed to determine which approach models material behavior accurately with the …
Date: December 14, 2000
Creator: Barney, M M; Campbell, G H; Stolken, J S; Schwartz, A J; Plitzko, J; King, W E et al.
Object Type: Article
System: The UNT Digital Library
Case study of isosurface extraction algorithm performance (open access)

Case study of isosurface extraction algorithm performance

Isosurface extraction is an important and useful visualization method. Over the past ten years, the field has seen numerous isosurface techniques published leaving the user in a quandary about which one should be used. Some papers have published complexity analysis of the techniques yet empirical evidence comparing different methods is lacking. This case study presents a comparative study of several representative isosurface extraction algorithms. It reports and analyzes empirical measurements of execution times and memory behavior for each algorithm. The results show that asymptotically optimal techniques may not be the best choice when implemented on modern computer architectures.
Date: December 14, 1999
Creator: Sutton, P M; Hansen, C D; Shen, H & Schikore, D
Object Type: Article
System: The UNT Digital Library
A Generalized Fast Frequency Sweep Algorithm for Coupled Circuit-EM Simulations (open access)

A Generalized Fast Frequency Sweep Algorithm for Coupled Circuit-EM Simulations

An Asymptotic Wave Expansion (AWE) technique is implemented into the EIGER computational electromagnetics code. The AWE fast frequency sweep is formed by separating the components of the integral equations by frequency dependence, then using this information to find a rational function approximation of the results. The standard AWE method is generalized to work for several integral equations, including the EFIE for conductors and the PMCHWT for dielectrics. The method is also expanded to work for two types of coupled circuit-EM problems as well as lumped load circuit elements. After a simple bisecting adaptive sweep algorithm is developed, dramatic speed improvements are seen for several example problems.
Date: December 14, 2004
Creator: Ouyang, G.; Jandhyala, V.; Champagne, N.; Sharpe, R.; Fasenfest, B. J. & Rockway, J. D.
Object Type: Report
System: The UNT Digital Library
Second Order Optical Nonlinearities in Thermally Poled Phosphate Glasses (open access)

Second Order Optical Nonlinearities in Thermally Poled Phosphate Glasses

Second order optical nonlinearities were induced in commercial phosphate glasses (Schott, IOG-1) by the thermal poling technique. The induced {chi}{sup (2)} was measured via second harmonic generation using a fundamental beam from a 1064 nm mode-locked Nd:YAG laser. The nonlinear regions were characterized using the Maker-Fringe technique, in which the second harmonic signals were observed as a function of incident angle of the fundamental beam. The results show that the {chi}{sup (2)} profile has contributions from two distinct regions: a near-anodic surface region and a bulk. We have modeled the induced profile to fit our experimental results. The dependence of the induced nonlinearity on applied poling fields, temperatures and poling time is discussed.
Date: December 14, 2001
Creator: Thamboon, P & Krol, D
Object Type: Article
System: The UNT Digital Library
Advancing Climate and Carbon Simulation (open access)

Advancing Climate and Carbon Simulation

We use a recently developed integrated climate/carbon model to perform breakthrough studies of the climate. Two major studies are carried out--namely the effects of CO{sub 2}-fertilized vegetation on global climate and carbon dynamics, and the effect of climate sensitivity on carbon cycle feedback. We have also begun development of a next-generation climate/carbon modeling capability.
Date: December 14, 2004
Creator: Thompson, S.
Object Type: Report
System: The UNT Digital Library
Limits of pile operating level (open access)

Limits of pile operating level

This report, compiled by Mr. W. R. Lewis of the Pile Technology Division, is a revision of Document HW-15516 (January 5, 1950) in consideration of new knowledge obtained during the past year. The document discusses the technical factors involved in attaining higher power levels in the various Hanford Piles. The purpose of this presentation is to summarize the present operating limitations and the possibilities of increased production rates. The limitations discussed are: A. Reactivity and flattening; B. Aluminum thimbles; C. Graphite temperature considerations; D. Boiling or vapor binding considerations; E. Tube and slug jacket corrosion; F. Effluent water activity; G. Distortion of the biological shields; H. Radiation considerations; and I. Pile control system capacity.
Date: December 14, 1950
Creator: Woods, W. K. & Lee, E. P.
Object Type: Report
System: The UNT Digital Library
SP-100 operational life model. Fiscal Year 1990 annual report (open access)

SP-100 operational life model. Fiscal Year 1990 annual report

This report covers the initial year`s effort in the development of an Operational Life Model (OLM) for the SP-100 Space Reactor Power System. The initial step undertaken in developing the OLM was to review all available documentation from GE on their plans for the OLM and on the degradation and failure mechanisms envisioned for the SP-100. In addition, the DEGRA code developed at JPL, which modelled the degradation of the General Purpose Heat Source based Radioisotope Thermoelectric Generator (GPHS-RTG), was reviewed. Based on the review of the degradation and failure mechanisms, a list of the most pertinent degradation effects along with their key degradation mechanisms was compiled. This was done as a way of separating the mechanisms from the effects and allowing all of the effects to be incorporated into the OLM. The emphasis was on parameters which will tend to change performance as a function of time and not on those that are simply failures without any prior degradation.
Date: December 14, 1990
Creator: Ewell, R. & Awaya, H.
Object Type: Report
System: The UNT Digital Library
Effect of stainless steel thimbles on pile reactivity (open access)

Effect of stainless steel thimbles on pile reactivity

Failure of a vertical safety rod thimble at 105-B has led to consideration of a stainless steel (SS) thimble as replacement. 1/16 in. SS would result in 4% loss in control power of that safety rod. If all thimbles were replaced by 1/16 in. SS, there would be a reactivity loss of 790 ih.
Date: December 14, 1945
Creator: Marshall, L. W.
Object Type: Report
System: The UNT Digital Library
Composition of ending inventory, November 1966 (open access)

Composition of ending inventory, November 1966

Submitted herewith are source and special nuclear material composition of ending inventory reports for the month of November 1966. The depleted uranium, enriched uranium, plutonium, enriched lithium, U-233, normal uranium, neptunium 237, plutonium 238, deuterium, tritium, and thorium compositions are all broken down.
Date: December 14, 1966
Creator: Budd, R. O.
Object Type: Report
System: The UNT Digital Library
Reactivity accounting by ``CALHOT``, a one-group one-dimensional buckling code (open access)

Reactivity accounting by ``CALHOT``, a one-group one-dimensional buckling code

Normal Pile exposure variations and day-to-day operating reactivity adjustments must be compensated by a combination of in-reactor poison and enrichment. The calculation of current reactivity status and the prediction of future trends is an integral part of the Physicist`s responsibility. This document describes the computer program ``CALHOT,`` which is based upon one-group diffusion theory, and is intended to be used in routine reactivity-enrichment calculations. It offers the advantages over present hand calculations of greater accuracy, more flexibility, and, most important, much less calculational time.
Date: December 14, 1962
Creator: Chitwood, R. A. & Toyooka, R. T.
Object Type: Report
System: The UNT Digital Library
Linkage of anthropogenic aerosol to clouds and climate. Progress report No. 3 (open access)

Linkage of anthropogenic aerosol to clouds and climate. Progress report No. 3

During the first year of this project equipment was built to obtain direct droplet measurement data from a mobile platform in fog (or mountain impacted stratum) and to characterize CCN according to particle volatility (thermal processing). Since the start date, July 15, 1990, was during the California stratus season and it was necessary to complete the construction of equipment and allow time before a field project it was not possible to begin field work until the summer of 1991. This report discusses surface measurements made in 1991 and 1992 as well as the SEAHUNT (Shiptrail Evolution Above High Updraft Naval Targets) Project and the ASTEX (Atlantic Stratocumulus Transition Experiment) Project.
Date: December 14, 1992
Creator: Hudson, J. G.
Object Type: Report
System: The UNT Digital Library
Technology development for cobalt F-T catalysts. Quarterly technical progress report No. 4, July 1, 1993--September 30, 1993 (open access)

Technology development for cobalt F-T catalysts. Quarterly technical progress report No. 4, July 1, 1993--September 30, 1993

The goal of this project is the development of a commercially viable, cobalt-based Fischer-Tropsch (F-T) catalyst for use in a slurry bubble column reactor. Cobalt-based catalysts have long been known as being active for F-T synthesis. They typically possess greater activity than iron-based catalysts, historically the predominant catalyst being used commercially for the conversion of syngas based on coal, but possess two disadvantages that somewhat lessen its value: (1) cobalt tends to make more methane than iron does, and (2) cobalt is less versatile with low H2/CO ratio syngas due to its lack of water-gas shift activity. Therefore, the major objectives of this work are (1) to develop a cobalt-based F-T catalyst with low ( < 5 %) methane selectivity, (2) to develop a cobalt-based F-T catalyst with water-gas shift activity, and (3) to combine both these improvements into one catalyst. It will be demonstrated that these catalysts have the desired activity, selectivity, and life, and can be made reproducibly. Following this experimental work, a design and a cost estimate will be prepared for a plant to produce sufficient quantities of catalyst for scale-up studies.
Date: December 14, 1993
Creator: Singleton, A. H.
Object Type: Report
System: The UNT Digital Library
Anisotropy and spatial variation of relative permeability and lithologic character of Tensleep Sandstone reservoirs in the Bighorn and Wind River basins, Wyoming. First quarterly technical progress report, September 15, 1993--December 14, 1993 (open access)

Anisotropy and spatial variation of relative permeability and lithologic character of Tensleep Sandstone reservoirs in the Bighorn and Wind River basins, Wyoming. First quarterly technical progress report, September 15, 1993--December 14, 1993

This multidisciplinary study is designed to provide improvements in advanced reservoir characterization techniques. This goal is to be accomplished through: (1) an examination of the spatial variation and anisotropy of relative permeability in the Tensleep Sandstone reservoirs of Wyoming; (2) the placement of that variation and anisotropy into paleogeographic, depositional, and diagenetic frameworks; (3) the development of pore-system imagery techniques for the calculation of relative permeability; and (4) reservoir simulations testing the impact of relative permeability anisotropy and spatial variation on Tensleep Sandstone reservoir enhanced oil recovery. Concurrent efforts are aimed at understanding the spatial and dynamic alteration in sandstone reservoirs that is caused by rock-fluid interaction during CO{sub 2} enhanced oil recovery processes. The work focuses on quantifying the interrelationship of fluid-rock interaction with lithologic characterization in terms of changes in relative permeability, wettability, and pore structure, and with fluid characterization in terms of changes in chemical composition and fluid properties. This work will establish new criteria for the susceptibility of Tensleep Sandstone reservoirs to formation alteration that results in a change in relative permeability and wellbore scale damage. This task will be accomplished by flow experiments using core material; examination of regional trends in water chemistry; examination of …
Date: December 14, 1993
Creator: Dunn, T. L.
Object Type: Report
System: The UNT Digital Library
The concentration of radionuclides and metals in vegetation adjacent to and in the SRL Seepage Basins (open access)

The concentration of radionuclides and metals in vegetation adjacent to and in the SRL Seepage Basins

In 1991 the trees on the dikes surrounding the SRL Seepage Basins were sampled and analyzed to inventory the contaminants transported from the basins into the vegetation. Tree leaves and wood were collected and analyzed for {sup 90}Sr, {sup 60}Co, {sup 137}Cs, {sup 238}Pu, {sup 239,240}Pu, {sup 242,244}Cm, {sup 241}Am, Ba, Cr, Hg, Mg, Mn, Ni, and Pb. The concentrations of contaminants were influenced by sample type (leaves versus wood), species type (pines versus hardwoods), and location relative to distance from the basin. The total inventory of each contaminant in the trees was estimated. The relationships between leaf and wood, pines and hardwood, location, and mass of the material in each of these classes were used to weight the total inventory estimate. The radionuclide with the largest inventory was 0.7 mCi for {sup 90}Sr. The metallic contaminant with the largest inventory was Mn at 200 gm.
Date: December 14, 1992
Creator: Murphy, C. E. Jr.
Object Type: Report
System: The UNT Digital Library
Enzymatic desulfurization of coal. Sixth quarterly report, September 16--December 15, 1989 (open access)

Enzymatic desulfurization of coal. Sixth quarterly report, September 16--December 15, 1989

Our experimental approach focuses on the use of enzymes which catalyze the addition of oxygen to organic compounds., In tailoring the application of these enzymes to coal processing, we are particularly interested in ensuring that oxidation occurs at sulfur and not at carbon-carbon bonds. Previous studies with DBT have shown that the reaction most frequently observed in microbial oxidative pathways is one in which DBT is oxidized at ring carbons. These reactions, as we have said, are accompanied by a considerable decrease in the energy content of the compound. In addition, microbial pathways have been identified in which the sulfur atom is sequentially oxidized to sulfoxide, to sulfone, to sulfonate, and finally to sulfuric acid. In this case, the fuel value of the desulfurized compounds is largely retained. We are evaluating the potential of commercially available enzymes to perform this function.
Date: December 14, 1989
Creator: Boyer, Y. N.; Crooker, S. C.; Kitchell, J. P. & Nochur, S. V.
Object Type: Report
System: The UNT Digital Library
Fire hazards analysis for W-413, West Area Tank Farm Storage and Staging Facility (open access)

Fire hazards analysis for W-413, West Area Tank Farm Storage and Staging Facility

In accordance with DOE Order 5480.7A, a Fire Hazards Analysis must be performed for all new facilities. The purpose of the analysis is to comprehensively assess the risk from fire within individual fire areas in relation to proposed fire protection so as to ascertain whether the fire protection objectives of the Order are met. The Order acknowledges a graded approach commensurate with the hazards involved. Tank Farms Operations must sore/stage material and equipment such as pipes, fittings, conduit, instrumentation and others related items until work packages are ready to work. Consumable materials, such as nut, bolts and welding rod, are also requires to be stored for routine and emergency work. Connex boxes and open storage is currently used for much of the storage because of the limited space at and 272WA. Safety issues based on poor housekeeping and material deteriorating due to weather damage has resulted from this inadequate storage space. It has been determined that a storage building in close proximity to the Tank Farm work force would be cost effective. This facility is classified as a safety class 4 building.
Date: December 14, 1994
Creator: Huckfeldt, R. A. & Lott, D. T.
Object Type: Report
System: The UNT Digital Library
Irradiation Processing Department Monthly Report: November 1962 (open access)

Irradiation Processing Department Monthly Report: November 1962

This document details activities of the Irradiation Processing Department during the month of November, 1962. A general summary is included at the start of the report, after which the report is divided into the following sections: Research and Engineering Operations; Production and Reactor Operations; Facilities Engineering Operation; Employee Relations Operation; and Financial Operation.
Date: December 14, 1962
Creator: Hanford Atomic Products Operation. Irradiation Processing Department.
Object Type: Report
System: The UNT Digital Library
Hanford Laboratories Operation Monthly Activities Report: November 1962 (open access)

Hanford Laboratories Operation Monthly Activities Report: November 1962

This is the monthly report for the Hanford Laboratories Operation, November 1962. Metallurgy, reactor fuels, chemistry, dosimetry, separation processes, reactor technology, financial activities, visits, biology operation, physics and instrumentation research, and employee relations are discussed.
Date: December 14, 1962
Creator: Hanford Laboratories
Object Type: Report
System: The UNT Digital Library