States

Thermal-sprayed, thin-film pyrite cathodes for thermal batteries -- Discharge-rate and temperature studies in single cells (open access)

Thermal-sprayed, thin-film pyrite cathodes for thermal batteries -- Discharge-rate and temperature studies in single cells

Using an optimized thermal-spray process, coherent, dense deposits of pyrite (FeS{sub 2}) with good adhesion were formed on 304 stainless steel substrates (current collectors). After leaching with CS{sub 2} to remove residual free sulfur, these served as cathodes in Li(Si)/FeS{sub 2} thermal cells. The cells were tested over a temperature range of 450 C to 550 C under baseline loads of 125 and 250 mA/cm{sup 2}, to simulate conditions found in a thermal battery. Cells built with such cathodes outperformed standard cells made with pressed-powder parts. They showed lower interracial resistance and polarization throughout discharge, with higher capacities per mass of pyrite. Post-treatment of the cathodes with Li{sub 2}O coatings at levels of >7% by weight of the pyrite was found to eliminate the voltage transient normally observed for these materials. Results equivalent to those of standard lithiated catholytes were obtained in this manner. The use of plasma-sprayed cathodes allows the use of much thinner cells for thermal batteries since only enough material needs to be deposited as the capacity requirements of a given application demand.
Date: May 25, 2000
Creator: GUIDOTTI,RONALD A.; REINHARDT,FREDERICK W.; DAI,JINXIANG; XIAO,T. DANNY & REISNER,DAVID
Object Type: Article
System: The UNT Digital Library
Heat Transfer in Cane Fiberboard Exposed to Hypothetical Accident Conditions (open access)

Heat Transfer in Cane Fiberboard Exposed to Hypothetical Accident Conditions

Radioactive material packages containing fiberboard insulation have been subjected to Hypothetical Accident Condition (HAC) thermal tests for many years. Historically, the packages` thermal performance has always been difficult to grasp. A package designer needs to understand the effects of temperature and pyrolysis on the rate of heat transfer and performance. This paper describes in detail the one-dimensional HAC thermal tests performed on fiberboard to understand the effects of pyrolysis, its char and its gas products. The tests were conducted by the Packaging and Transportation Group at the Savannah River Site (SRS). Test fixtures were assembled at SRS and thermal testing conducted in the Radiant Heat Facility at the Sandia National Laboratories. Descriptions of the test fixtures are provided, as well as the time dependent temperature profiles. In addition, lessons learned are discussed.
Date: May 25, 1995
Creator: Gromada, R.J.
Object Type: Article
System: The UNT Digital Library
Surveillance of Site A and Plot M - Report for 1999. (open access)

Surveillance of Site A and Plot M - Report for 1999.

The results of the environmental surveillance program conducted at Site A/Plot M in the Palos Forest Preserve area for Calendar Year 1999 are presented. Based on the results of the 1976-1978 radiological characterization of the site, a determination was made that a surveillance program be established. The characterization study determined that very low levels of hydrogen-3 (as tritiated water) had migrated from the burial ground and were present in two nearby hand-pumped picnic wells. The current surveillance program consists of sample collection and analysis of surface and subsurface water. The results of the analyses are used to (1) monitor the migration pathway of water from the burial ground (Plot M) to the handpumped picnic wells, (2) establish if buried radionuclides other than hydrogen-3 have migrated, and (3) generally characterize the radiological environment of the area. Hydrogen-3 in the Red Gate Woods picnic wells was still detected this year, but the average and maximum concentrations were significantly less than found earlier. Tritiated water continues to be detected in a number of wells, boreholes, dolomite holes, and a surface stream. For many years it was the only radionuclide found to have migrated in measurable quantities. Analyses since 1984 have indicated the presence …
Date: May 25, 2000
Creator: Golchert, N. W.
Object Type: Report
System: The UNT Digital Library
Effects of He{sup +} ion implantation on optical and structural properties of MgAl{sub 2}O{sub 4} (open access)

Effects of He{sup +} ion implantation on optical and structural properties of MgAl{sub 2}O{sub 4}

Single crystals of magnesium-aluminate spinel were implanted with 170 keV He{sup +} ions to fluences ranging from 1 x 10{sup 16}--1 x 10{sup 21} ions/m{sup 2} at 120 K. The effects of ion implantation were studied using optical absorption spectroscopy, Rutherford Backscattering Spectroscopy and Ion Channeling (RBS/C) and Transmission Electron Microscopy (TEM). In absorption spectra obtained from the implanted samples, growth of an F-center band at 5.3 eV was observed. At the fluence of 3 x 10{sup 20} ions/m{sup 2}, the growth of this band not only ceases but the intensity suddenly decreases. This may be due to formation of a new phase at this fluence. This is partially confirmed by the fact that beginning at this dose, a modulated absorbance becomes apparent in the absorption spectrum of spinel. This effect is caused by formation of a buried layer with refraction index lower than that of an unimplanted sample. RBS/C and TEM measurements show that spinel is not amorphized over the fluence range examined in this study. TEM microdiffraction observations show that in the damaged region the intensities of superlattice spots decrease significantly, suggesting that ion beam irradiation induces either an order-disorder phase transition or a transformation into the so-called …
Date: May 25, 1999
Creator: Afanasyev-Charkin, I. V.; Cooke, D. W.; Gritsyna, V. T.; Ishimaru, M. & Sickafus, K. E.
Object Type: Article
System: The UNT Digital Library
Preferential recycling/rejection in CFBC/FBC systems using triboelectrostatic separation (open access)

Preferential recycling/rejection in CFBC/FBC systems using triboelectrostatic separation

Circulating Fluidized Bed Combustion (CFBC) and Fluidized Bed Combustion (FBC) with recirculation are widely used technologies in the US for power generation. They have the advantage of fuel flexibility, and low NO{sub x} and SO{sub x} emissions. Typically, as partially combusted fuel is circulated in the system, only a split stream of this circulating stream is rejected, with remainder recycled to the combustor. As a consequence, there is unburned carbon and partially used, valuable, calcium hydroxide in the reject stream. If these useful materials in the reject stream can be recovered and sent back to the combustor, the efficiency of the system will be increased significantly and the equivalent emissions will be lower. This project studies an innovative concept to incorporate triboelectric separation into CFBC/FBC systems in order to preferentially split its recycle/reject streams based on material compositions of the particles. The objective is to answer whether useful constituents, like carbon, calcium carbonate and calcium hydroxide or oxide, can be selectively separated from combustion ash at elevated temperatures. Laboratory experimental studies are performed at temperatures from 25 C to 210 C, the data from which are presented in the form of recovery curves. These curves present quality-versus-quantity information useful for …
Date: May 25, 2000
Creator: Ban, Heng & Stencel, J.M.
Object Type: Report
System: The UNT Digital Library
Uranium Density and Enrichment in Fuel Tubes Determined from 232U and 235U Y-Activities (open access)

Uranium Density and Enrichment in Fuel Tubes Determined from 232U and 235U Y-Activities

Gamma spectroscopy is used to determine 235U density and enrichment in U-Al fuel tubes containing recycled fuel. A collimated HPGe Y-detector views the tube surface, such that U-Al disk volumes of 6.35 mm diameter and approximately 1.0 mm thickness are examined. The Y-activities from 232U and 235U, along with the tube design parameters, are used to deduce the attenuation-corrected results. Respective density and enrichment variations of less than 1 percent and less than 0.6e percent were measurable with 2000 sec counting time per tube location. Such measurements are useful for certifying tube quality and characterizing problems associated with blending the U-Al alloy.
Date: May 25, 1984
Creator: Winn, Willard G.
Object Type: Article
System: The UNT Digital Library
An indirect sensing technique for diesel fuel quantity control. Final report (open access)

An indirect sensing technique for diesel fuel quantity control. Final report

None
Date: May 25, 1999
Creator: MacCarley, C. Arthur
Object Type: Report
System: The UNT Digital Library
Coulomb Driven New Bound States at the Integer Quantum Hall States in GaAs/Al(0.3)Ga(0.7)As Single Heterojunctions (open access)

Coulomb Driven New Bound States at the Integer Quantum Hall States in GaAs/Al(0.3)Ga(0.7)As Single Heterojunctions

Coulomb driven, magneto-optically induced electron and hole bound states from a series of heavily doped GaAs/Al<sub>0.3</sub>Ga<sub>0.7</sub>As single heterojunctions (SHJ) are revealed in high magnetic fields. At low magnetic fields ({nu} >2), the photohuninescence spectra display Shubnikov de-Haas type oscillations associated with the empty second subband transition. In the regime of the Landau filling factor {nu} <1 and 1< {nu} <2, we found strong bound states due to Mott type Vocalizations. Since a SHJ has an open valence band structure, these bound states area unique property of the dynamic movement of the valence holes in strong magnetic fields.
Date: May 25, 1999
Creator: Jiang, H. W.; Kim, Yongmin; Lee, Kyu-Seok; Lee, X.; Munteanu, F. M.; Perry, C. H. et al.
Object Type: Article
System: The UNT Digital Library
Superheavy dark Matter (open access)

Superheavy dark Matter

If there exists fields of mass of the order of 10{sup 13} GeV and large field inflation occurs, their interaction with classical gravitation will generate enough particles to give the universe critical density today regardless of their nongravitational coupling. In the standard dark matter scenarios, WIMPs are usually considered to have once been in local thermodynamic equilibrium (LTE), and their present abundance is determined by their self-annihilation cross section. In that case, unitarity and the lower bound on the age of the universe constrains the mass of the relic to be less than 500 TeV. On the other hand, if the DM particles never attained LTE in the past, self-annihilation cross section does not determine their abundance. For example, axions, which may never have been in LTE, can have their abundance determined by the dynamics of the phase transition associated with the breaking of U(1){sub PQ}. These nonthermal relics (ones that never obtained LTE) are typically light. However, there are mechanisms that can produce superheavy (many orders of magnitude greater than the weak scale) nonthermal relics. Some of this is reviewed in reference 2. Although not known at the time when this talk was given, it is now known that …
Date: May 25, 2000
Creator: Chung, Daniel
Object Type: Article
System: The UNT Digital Library
Studies of hadron-electron separators for the ZEUS barrel calorimeter (open access)

Studies of hadron-electron separators for the ZEUS barrel calorimeter

Two possible upgrades, a shower maximum detector and a presampler, designed to improve the low energy electron/hadron separation capabilities of the ZEUS barrel calorimeter are described and test-beam results are reported. The presampler can also be used to correct for energy loss of particles traversing the dead material in front of the calorimeter.
Date: May 25, 1995
Creator: Ambats, I.; Bortz, D. & Connolly, A.
Object Type: Report
System: The UNT Digital Library
Preferential recycling/rejection in CFBC/FBC systems using triboelectrostatic separation (open access)

Preferential recycling/rejection in CFBC/FBC systems using triboelectrostatic separation

Circulating Fluidized Bed Combustion (CFBC) and Fluidized Bed Combustion (FBC) with recirculation are widely used technologies in the US for power generation. They have the advantage of fuel flexibility, and low NO{sub x} and SO{sub x} emissions. Typically, as partially combusted fuel is circulated in the system, only a split stream of this circulating stream is rejected, with remainder recycled to the combustor. As a consequence, there is unburned carbon and partially used, valuable, calcium hydroxide in the reject stream. If these useful materials in the reject stream can be recovered and sent back to the combustor, the efficiency of the system will be increased significantly and the equivalent emissions will be lower. This project studies an innovative concept to incorporate triboelectric separation into CFBC/FBC systems in order to preferentially split its recycle/reject streams based on material compositions of the particles. The objective is to answer whether useful constituents, like carbon, calcium carbonate and calcium hydroxide or oxide, can be selectively separated from combustion ash at elevated temperatures. Laboratory experimental studies are performed at temperatures from 25 C to 210 C, the data from which are presented in the form of recovery curves. These curves present quality-versus-quantity information useful for …
Date: May 25, 2000
Creator: Ban, Heng & Stencel, J.M.
Object Type: Report
System: The UNT Digital Library
Tests of QCD using Heavy Flavors in e+e--&gt;Z0 at SLD (open access)

Tests of QCD using Heavy Flavors in e+e--&gt;Z0 at SLD

We present preliminary results on three SLD analyses: the gluon energy spectrum in 3-jet b{bar b}g events, the rate of g {r_arrow} b{bar b}, and the b fragmentation function in Z{sup 0} decays. The gluon energy spectrum, measured over the full kinematic range, is compared with perturbative QCD predictions. We set new 95% C.L. limits on the anomalous chromomagnetic coupling of the b quark: {minus}0.09 &lt; {kappa} &lt; 0.06. g{sub b{bar b}} is measured to be (3.07 {+-} 0.71 (stat) {+-} 0.66 (syst)) x 10{sup {minus}3}. The inclusive B hadron energy distribution is measured for the first time over the full kinematic range, using a novel B hadron energy reconstruction technique. Several models of b fragmentation including JETSET + Peterson are excluded by the data. The average scaled B hadron energy of the weakly decaying B hadron is measured to be x{sub B} = 0.713 {+-} 0.005 (stat) {+-} 0.007 (syst) {+-} 0.002 (model). All three measurements take advantage of the small and stable SLC interaction point as well as the excellent vertexing and tracking capabilities of the upgraded CCD-pixel vertex detector.
Date: May 25, 1999
Creator: Dong, Danning
Object Type: Report
System: The UNT Digital Library
Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane. Quarterly technical progress report 8, January--March, 1995 (open access)

Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane. Quarterly technical progress report 8, January--March, 1995

Activities during this quarter focused on fine tuning of catalyst characterization and synthesis techniques. Improvements in catalyst activity test methods were also implemented but more remains to be done. Specific accomplishments include: improved characterization of vanadyl pyrophosphate (VPO) and Si promoted VPO by FTIR and FTIR of chemisorbed bases; several minor improvements in catalyst preparation technique resulting in enhanced catalyst yield, better control of catalyst composition, and generation of less waste; preliminary pulsed reaction data on methane oxidation were also acquired. Preliminary activity measurements for methane conversion (without oxygen) in a pulsed reactor over VPO indicate that the primary reaction product is CO. Carbon dioxide is also formed but selectivity to CO{sub 2} decreases with number of pulses. These results suggest that selectivity to partially oxidized products improves with catalyst reduction and suggest that some surface modification will be required to obtain oxidized hydrocarbon products. Note that catalyst activation (conversion from the precursor to VPO) has been carried out using air. For butane oxidation catalysts VPO is activated in a 1% butane/air mixture which produces a slightly reduced catalyst.
Date: May 25, 1995
Creator: McCormick, R.L.
Object Type: Report
System: The UNT Digital Library
Localized weld metal corrosion in stainless steel water tanks (open access)

Localized weld metal corrosion in stainless steel water tanks

The rapidly developed leaks within the TFC and TFD tanks (LLNL groundwater treatment facilities) were caused by localized corrosion within the resolidified weld metal. The corrosion was initiated by the severe oxidation of the backsides of the welds which left the exposed surfaces in a condition highly susceptible to aqueous corrosion. The propagation of surface corrosion through the thickness of the welds occurred by localized corrosive attack. This localized attack was promoted by the presence of shielded aqueous environments provided by crevices at the root of the partial penetration welds. In addition to rapid corrosion of oxidized surfaces, calcium carbonate precipitation provided an additional source of physical shielding from the bulk tank environment. Qualification testing of alternate weld procedures showed that corrosion damage can be prevented in 304L stainless steel GTA welds by welding from both sides while preventing oxidation of the tank interior through the use of an inert backing gas such as argon. Corrosion resistance was also satisfactory in GMA welds in which oxidized surfaces were postweld cleaned by wire brushing and chemically passivated in nitric acid. Further improvements in corrosion resistance are expected from a Mo-containing grade of stainless steel such as type 316L, although test results …
Date: May 25, 1995
Creator: Strum, M.J.
Object Type: Report
System: The UNT Digital Library
Sedimentological and geophysical studies of clastic reservoir analogs: Methods, applications and developments of ground-penetrating radar for determination of reservoir geometries in near-surface settings. Final report (open access)

Sedimentological and geophysical studies of clastic reservoir analogs: Methods, applications and developments of ground-penetrating radar for determination of reservoir geometries in near-surface settings. Final report

An integrated sedimentologic and GPR investigation has been carried out on a fluvial channel sandstone in the mid-Cretaceous Ferron Sandstone at Coyote Basin along the southwestern flank of the San Rafael Uplift in east-central Utah. This near-surface study, which covers a area of 40 {times} 16.5 meters to a depth of 15 meters, integrates detailed stratigraphic data from outcrop sections and facies maps with multi-frequency 3-D GPR surveys. The objectives of this investigation are two-fold: (1) to develop new ground-penetrating radar (GPR) technology for imaging shallow subsurface sandstone bodies, and (2) to construct an empirical three-dimensional sandstone reservoir model suitable for hydrocarbon flow-simulation by imaging near-surface sandstone reservoir analogs with the use of GPR. The sedimentological data base consists of a geologic map of the survey area and a detailed facies map of the cliff face immediately adjacent to the survey area. Five vertical sections were measured along the cliff face adjacent to the survey area. In addition, four wells were cored within the survey area from which logs were recorded. In the sections and well logs primary sedimentary structures were documented along with textural information and permeability data. Gamma-ray profiles were also obtained for all sections and core logs. …
Date: May 25, 1998
Creator: McMechan, G.A. & Soegaard, K.
Object Type: Report
System: The UNT Digital Library
Calculation of unmitigated release from reverse circulation drilling of a borehole three meters south of borehole 41-15-09 near SST 241-SX-115 (open access)

Calculation of unmitigated release from reverse circulation drilling of a borehole three meters south of borehole 41-15-09 near SST 241-SX-115

It is known that underground, single shell tank (SST) 241-SX-115 leaked 50,000 gallons of contaminated liquid to the soil. Now there is a campaign to more fully characterize the plume from that leak. To determine radionuclide concentrations in the vadose zone, boring into the soil and collecting samples of it are needed. It was decided to bore a new hole 3 m (9.8 ft) from existing borehole number 41-15-09, located near the south edge of the tank. Drilling and sampling will be done with the use of reverse circulation drilling, which uses compressed air to power the drill bit and sweep out drillings into separation and sampling equipment. Prior to drilling, however, it was determined that safety assessment calculations were needed to find out if postulated releases from the drilling would pose unacceptable risk to onsite and offsite receptors. Unacceptable risk would require the design and construction of safety significant equipment for prevention or mitigation of the release.
Date: May 25, 1999
Creator: SCOTT, D.L.
Object Type: Report
System: The UNT Digital Library
Final report to US Department of Energy: Cyclotron autoresonance accelerator for electron beam dry scrubbing of flue gases (open access)

Final report to US Department of Energy: Cyclotron autoresonance accelerator for electron beam dry scrubbing of flue gases

Several designs have been built and operated of microwave cyclotron autoresonance accelerators (CARA's) with electron beam parameters suitable for remediation of pollutants in flue gas emissions from coal-burning power plants. CARA designs have also been developed with a TW-level 10.6 micron laser driver for electron acceleration from 50 to 100 MeV, and with UHF drivers for proton acceleration to over 500 MeV. Dose requirements for reducing SO2, NOx, and particulates in flue gas emissions to acceptable levels have been surveyed, and used to optimize the design of an electron beam source to deliver this dose.
Date: May 25, 2001
Creator: Hirshfield, J. L.
Object Type: Report
System: The UNT Digital Library
Bioethanol: Fueling sustainable transportation (open access)

Bioethanol: Fueling sustainable transportation

Ethanol made from biomass, or bioethanol, can positively impact the national energy security, the economy, and the environment. Producing and using bioethanol can help alleviate some of the negative impacts of the dependence on fossil fuels.
Date: May 25, 2000
Creator: Neufeld, S.
Object Type: Book
System: The UNT Digital Library
Radiological considerations for top-up operation of the storage ring. (open access)

Radiological considerations for top-up operation of the storage ring.

Radiological considerations for the operation of the storage ring prior to top-up operation have been discussed in the document (MOE 94). This document was prepared to serve as the technical basis for the hazard analysis considerations and the statements in the APS Safety Assessment Document (SAD) dealing with shielding adequacy and other radiological considerations. The methodology used in that document and, subsequently, in the analysis of hazards from the low-energy undulator test line (MOE 98) was also used for shielding analysis and dose determinations in this document. The hazards and potential consequences of storage ring (SR) operation covered in (MOE 94) still apply to non-top-up operations of the SR. Two additional issues relevant to top-up operation, which give rise to potential radiological considerations, are (1) the possible use of the vertical scraper in the booster-to-storage ring (BTS) line to control the amount of charge that is being delivered to the storage ring, and (2) the potential accident situations, which give rise to radiation doses to individuals on the experiment hall floor and SR roof. By introducing the scraper, a portion of the beam produces a shower in the tungsten scraper, which leads to radiation fields on the top of the …
Date: May 25, 1999
Creator: Moe, H. J.
Object Type: Report
System: The UNT Digital Library
Optical detection system for multispectral UV fluorescence laser remote sensing measurements (open access)

Optical detection system for multispectral UV fluorescence laser remote sensing measurements

A mobile laser remote sensing system is being developed for multispectral UV fluorescence detection of vapor, liquid, and solid effluents. TM system uses laser wavelengths between 250 and 400 nm to excite UV fluorescence spectra that can be used to detect and identify species in multicomponent chemical mixtures. With a scanning mirror assembly, the system is designed to map chemical concentrations with a range resolution of {approximately}5 m. In this paper we describe the optical detection system (scanning mirror assembly, 76 cm diameter collection telescope, relay optics, spectrometers, and detectors) associated data acquisition and control electronics. We also describe unique diagnostic software that is used for instrument setup and control.
Date: May 25, 1994
Creator: Tisone, G. C.; Clark, B.; Wakefield-Reyes, C.; Hargis, P. H., Jr.; Michie, B.; Downey, T. L. et al.
Object Type: Article
System: The UNT Digital Library
Calculated powder x-ray diffraction data for boron (open access)

Calculated powder x-ray diffraction data for boron

None
Date: May 25, 1973
Creator: Holcombe, C.E. Jr. & Coffey, A. L., Jr.
Object Type: Report
System: The UNT Digital Library
Design considerations for a two-phase turbine (open access)

Design considerations for a two-phase turbine

A two-phase turbine, using a low-quality steam-water mixture as a working fluid, was designed, built, and tested in the laboratory. Two-phase fluids are found naturally in most geothermal fields throughout the world and can also be used in the conversion of waste heat from industrial sources. The thermodynamic and fluid-dynamic properties of such fluid mixtures are reviewed, with specific reference to the selection and design of an appropriate expander. Various types of practically realizable expanders are considered, and the choice of a single-stage, axial-flow, impulse turbine is explained. Also the basic design parameters, including sizing and blade and nozzle geometry, are described.
Date: May 25, 1978
Creator: Comfort, W. J., III & Beadle, C.W.
Object Type: Article
System: The UNT Digital Library
Integrated Experimental and Modeling Studies to Predict the Impact Response of Explosives and Propellants (open access)

Integrated Experimental and Modeling Studies to Predict the Impact Response of Explosives and Propellants

Understanding and predicting the impact response of explosives and propellants remains a challenging area in the energetic materials field. Efforts are underway at LLNL (and other laboratories) to apply modern diagnostic tools and computational analysis to move beyond the current level of imprecise approximations towards a predictive approach more closely based on fundamental understanding of the relevant mechanisms. In this paper we will discuss a set of underlying mechanisms that govern the impact response of explosives and propellants: (a) mechanical insult (impact) leading to material damage and/or direct ignition; (b) ignition leading to flame spreading; (c) combustion being driven by flame spreading, perhaps in damaged materials; (d) combustion causing further material damage; (e) combustion leading to pressure build-up or relief; (f) pressure changes driving the rates of combustion and flame spread; (g) pressure buildup leading to structural response and damage, which causes many of the physical hazards. We will briefly discuss our approach to modeling up these mechanistic steps using ALE 3D, the LLNL hydrodynamic code with fully coupled chemistry, heat flow, mass transfer, and slow mechanical motion as well as hydrodynamic processes. We will identify the necessary material properties needed for our models, and will discuss our experimental efforts …
Date: May 25, 2005
Creator: Maienschein, J L; Nichols, A. L., III; Reaugh, J E; McClelland, M E & Hsu, P C
Object Type: Article
System: The UNT Digital Library
Evaluation of fuel particles (open access)

Evaluation of fuel particles

None
Date: May 25, 1965
Creator: Feild, A. L., Jr. & Brizes, W.F.
Object Type: Report
System: The UNT Digital Library