Low temperature, sulfur tolerant homogeneous catalysts for the water-gas shift reaction (open access)

Low temperature, sulfur tolerant homogeneous catalysts for the water-gas shift reaction

The purpose of this report is to update and reorganize our recent review on homogeneous catalysis of the water-gas shift reaction (WGSR) based on recent literature publications and patents. This updated version will serve as a means of selecting 10 candidate catalyst systems for use in developing effective, sulfur-tolerant, low temperature WGSR catalysts. This report discusses the variations possible in the basic chemistry associated with WGSR catalytic cycles, including basic, acidic, and neutral conditions. Then individual mechanism for specific WGSR catalyst systems are discussed. Finally, on the basis of the literature reports, a list is presented of candidate catalysts and basic systems we have chosen for study in Task 3.
Date: January 20, 1986
Creator: Laine, R. M.
Object Type: Report
System: The UNT Digital Library
Research in radiation monitoring survey instrumentation. Final report (open access)

Research in radiation monitoring survey instrumentation. Final report

Two low-power solid-state prototype readout units were developed, an LED display and a LCD display. This display output was in a bar-graph format, covering four-decades of information, with 10-segments per decade. The displays accept a frequency input, which is standardly available from several portable radiation-survey instruments. Both readout units will operate on two D-cell batteries (3.0 Volt), with a typical current drain requirement of 0.3 MA for the LED display and 30..mu..A for the LCD display. A wide-range electrometer circuit was also developed. The circuit covers an input current range from 10/sup -13/ A to 10/sup -8/ A. The output signal is a pulse whose frequency is directly proportional to input current. The circuit requires no high-megohm resistors, and is autoranging. Several candidate input amplifiers were analyzed and evaluated for use with the electrometer circuit.
Date: January 20, 1978
Creator: Blalock, T. V.; Kennedy, E. J.; Phillips, R. G. & Walker, E. W. Jr.
Object Type: Report
System: The UNT Digital Library
CHARACTERIZATION OF UO$sub 2$ POWDERS. Fourth Quarterly Report, July 10, 1961-October 10, 1961 (open access)

CHARACTERIZATION OF UO$sub 2$ POWDERS. Fourth Quarterly Report, July 10, 1961-October 10, 1961

Studies are described of UO/sub 2/ powders to determine the relation between properties of the powders and sinterability. The main effort during the period was devoted to correlation of the powder particle size distribution with the sintered density of pellets. The pressure applied during the green forming step of pellet production is shown to have a varied and considerable effect on ceramic particle size distribution in the pellets. (J.R.D.)
Date: January 20, 1962
Creator: Carpenter, J.F.; Kuhlman, C.W. & Nelson, R.A.
Object Type: Report
System: The UNT Digital Library
Site 300 hazardous-waste-assessment project. Interim report: December 1981. Preliminary site reconnaissance and project work plan (open access)

Site 300 hazardous-waste-assessment project. Interim report: December 1981. Preliminary site reconnaissance and project work plan

This document was prepared to outline the scope and objectives of the Hazardous Waste Assessment Project (HWAP) at Site 300. This project was initiated in October, 1981, to investigate the existing solid waste landfills in an effort to satisfy regulatory guidelines and assess the potential for ground-water contamination. This involves a site-specific investigation (utilizing geology, hydrology, geophysics and geochemistry) with the goal of developing an effective ground-water quality monitoring network. Initial site reconnaissance work has begun and we report the results, to date, of our geologic hydrogeologic studies. All known solid waste disposal locations are underlain by rocks of either the Late Miocene Neroly Formation or the Cierbo Formation, both of which are dominantly sandstones interbedded with shale and claystone. The existence of a regional confined (artesian) aquifer, as well as a regional water-table aquifer is postulated for Site 300. Preliminary analysis has led to an understanding of directions and depths of regional ground-water flow.
Date: January 20, 1982
Creator: Raber, E.; Helm, D.; Carpenter, D.; Peifer, D. & Sweeney, J.
Object Type: Report
System: The UNT Digital Library
Nature of atmospheric dust. Progress report to January 15, 1955 (open access)

Nature of atmospheric dust. Progress report to January 15, 1955

Optical microscopic examination of air- and rain-borne dust shows most of the particles to be less than one micron in diameter. Electron microscopic examination of the same dust shows predominantly clusters of particles whose individual diameters are in the range 200 to 1000 A. The residue obtained by filtering rain water through a millipore filter is found to be slightly radioactive in more than half the cases observed.
Date: January 20, 1955
Creator: Heininger, C. & Turkevich, J.
Object Type: Report
System: The UNT Digital Library
Liquid-Phase Methanol Process Development Unit: Installation, Operation, and Support Studies. Technical Progress Report No. 1, 28 September 1981-31 December 1981 (open access)

Liquid-Phase Methanol Process Development Unit: Installation, Operation, and Support Studies. Technical Progress Report No. 1, 28 September 1981-31 December 1981

During this period the Work Breakdown Structure Dictionary was established. Task 1 was completed with submittal of the Project Work Plan and the Quality Assurance Manual. CSI produced basic process design information and a preliminary flowsheet for the LaPorte LPMeOH PDU. APCI developed the flowsheet further and set up the process on APCI's process simulator. The flowsheet development revealed a number of major changes necessary in the existing LPM pilot plant; this has led to pursuit of a unified design concept. Approval was requested for the unified design concept as well as advanced schedule for relocation of the LPM unit and advanced procurement of long delivery equipment items. A number of preliminary heat and material balances were calculated for the LPMeOH PDU and preliminary process specifications were prepared for the equipment items. The final design basis was established. The design pressure was set at 1000 psig. Eight design operating cases were defined for the following range of reactor operating conditions: Pressure - 500 to 900 psig, Temperature - 220 to 270/sup 0/C, Liquid-Fluidized Space Velocity - 1000 to 4000 l/hr-kg catalyst, Liquid-Entrained Space Velocity - 2000 to 10,000 l/hr-kg catalyst, and Liquid-Entrained Catalyst Loading - 0.1 to 0.4 kg catalyst/l …
Date: January 20, 1982
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Current California legislative and regulatory activity impacting geothermal hydrothermal commercialization: a monitoring report. Report No. 1017 (open access)

Current California legislative and regulatory activity impacting geothermal hydrothermal commercialization: a monitoring report. Report No. 1017

Four key geothermal-impacting bills presently before the California legislature are described. Two deal with state financial backing for geothermal projects. The third relates to the use of the state's share of the BLM geothermal revenues and the fourth to the protection of sensitive hot springs. The current regulatory activities of the California Energy Commission, the California Division of Oil and Gas, and the counties are discussed. (MHR)
Date: January 20, 1980
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Applications of Micellar Enzymology to Clean Coal Technology (open access)

Applications of Micellar Enzymology to Clean Coal Technology

This project is designed to develop methods for pre-combustion coal remediation by implementing recent advances in enzyme biochemistry. The novel approach of this study is incorporation of hydrophilic oxidative enzymes in reverse micelles in an organic solvent. Enzymes from commercial sources or microbial extracts are being investigated for their capacity to remove organic sulfur from coal by oxidation of the sulfur groups, splitting of C-S bonds and loss of sulfur as sulfuric acid Dibenzothiophene (DBT) and ehtylphenylsulfide (EPS)are serving as serving as models of organic sulfur-containing components of coal in initial studies.
Date: January 20, 1990
Creator: Walsh, C. T.
Object Type: Report
System: The UNT Digital Library
Engineering design and analysis of advanced physical fine coal cleaning technologies (open access)

Engineering design and analysis of advanced physical fine coal cleaning technologies

This project is sponsored by the United States Department of Energy (DOE) for the Engineering Design and Analysis of Advanced Physical Fine Coal Cleaning Technologies. The major goal is to provide the simulation tools for modeling both conventional and advanced coal cleaning technologies. This DOE project is part of a major research initiative by the Pittsburgh Energy Technology Center (PETC) aimed at advancing three advanced coal cleaning technologies-heavy-liquid cylconing, selective agglomeration, and advanced froth flotation through the proof-of-concept (POC) level.
Date: January 20, 1992
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Image collapsing concentrators. Interim scientific report No. 2 (open access)

Image collapsing concentrators. Interim scientific report No. 2

A cylindrical Fresnel-type lens has been designed and ray traced that focuses approximately to lines over a 60/sup 0/ elevation angle interval. Forty stepped prism facets are configured on the inside surface of the lens, and the lens outer surface can be well approximated by a smooth circular arc. Especially contoured cylindrical subreflectors are described for concentrating the broad image fields of the lens onto a narrow fixed shelf. These image collapsing subreflectors also compensate for focal shortening with azimuth angle incidence variations over nearly a +-60/sup 0/ sector. Ray tracing on the lens and subreflector provide approximate energy distributions on the absorber shelf over the large acceptance angle intervals. The expected performance characteristics of a solar concentrator using the curved lens with facets on the inside surface are compared with a concentrator employing a straight stepped prism lens with facets cut on the outer lens surface.
Date: January 20, 1980
Creator: Sletten, C.J.
Object Type: Report
System: The UNT Digital Library
Optimal flux patterns in cellular metabolic networks (open access)

Optimal flux patterns in cellular metabolic networks

The availability of whole-cell level metabolic networks of high quality has made it possible to develop a predictive understanding of bacterial metabolism. Using the optimization framework of flux balance analysis, I investigate metabolic response and activity patterns to variations in the availability of nutrient and chemical factors such as oxygen and ammonia by simulating 30,000 random cellular environments. The distribution of reaction fluxes is heavy-tailed for the bacteria H. pylori and E. coli, and the eukaryote S. cerevisiae. While the majority of flux balance investigations have relied on implementations of the simplex method, it is necessary to use interior-point optimization algorithms to adequately characterize the full range of activity patterns on metabolic networks. The interior-point activity pattern is bimodal for E. coli and S. cerevisiae, suggesting that most metabolic reaction are either in frequent use or are rarely active. The trimodal activity pattern of H. pylori indicates that a group of its metabolic reactions (20%) are active in approximately half of the simulated environments. Constructing the high-flux backbone of the network for every environment, there is a clear trend that the more frequently a reaction is active, the more likely it is a part of the backbone. Finally, I briefly …
Date: January 20, 2007
Creator: Almaas, E
Object Type: Article
System: The UNT Digital Library
The complete chloroplast genome sequence of Pelargonium xhortorum: Or ganization and evolution of the largest and most highlyrearranged chloroplast genome of land plants (open access)

The complete chloroplast genome sequence of Pelargonium xhortorum: Or ganization and evolution of the largest and most highlyrearranged chloroplast genome of land plants

The chloroplast genome of Pelargonium e hortorum has beencompletely sequenced. It maps as a circular molecule of 217,942 bp, andis both the largest and most rearranged land plant chloroplast genome yetsequenced. It features two copies of a greatly expanded inverted repeat(IR) of 75,741 bp each, and consequently diminished single copy regionsof 59,710 bp and 6,750 bp. It also contains two different associations ofrepeated elements that contribute about 10 percent to the overall sizeand account for the majority of repeats found in the genome. Theyrepresent hotspots for rearrangements and gene duplications and include alarge number of pseudogenes. We propose simple models that account forthe major rearrangements with a minimum of eight IR boundary changes and12 inversions in addition to a several insertions of duplicated sequence.The major processes at work (duplication, IR expansion, and inversion)have disrupted at least one and possibly two or three transcriptionaloperons, and the genes involved in these disruptions form the core of thetwo major repeat associations. Despite the vast increase in size andcomplexity of the genome, the gene content is similar to that of otherangiosperms, with the exceptions of a large number of pseudogenes as partof the repeat associations, the recognition of two open reading frames(ORF56 and ORF42) …
Date: January 20, 2006
Creator: Chumley, Timothy W.; Palmer, Jeffrey D.; Mower, Jeffrey P.; Fourcade, H. Matthew; Calie, Patrick J.; Boore, Jeffrey L. et al.
Object Type: Article
System: The UNT Digital Library
Two-photon double ionization of H2 at 30 eV using Exterior Complex Scaling (open access)

Two-photon double ionization of H2 at 30 eV using Exterior Complex Scaling

Calculations of fully differential cross sections for two-photon double ionization of the hydrogen molecule with photons of 30 eV are reported. The results have been obtained by using the method of exterior complex scaling, which allows one to construct essentially exact wave functions that describe thedouble continuum on a large, but finite, volume. The calculated cross sections are compared with those previously obtained by Colgan et al., and discrepancies are found for specific molecular orientations and electron ejection directions.
Date: January 20, 2009
Creator: Morales, Felipe; Martin, Fernando; Horner, Daniel; Rescigno, Thomas N. & McCurdy, C. William
Object Type: Article
System: The UNT Digital Library
Analysis of Metabolic Pathways and Fluxes in a Newly Discovered Thermophilic and Ethanol-Tolerant Geobacillus Strain (open access)

Analysis of Metabolic Pathways and Fluxes in a Newly Discovered Thermophilic and Ethanol-Tolerant Geobacillus Strain

A recently discovered thermophilic bacterium, Geobacillus thermoglucosidasius M10EXG, ferments a range of C5 (e.g., xylose) and C6 sugars (e.g., glucose) and istolerant to high ethanol concentrations (10percent, v/v). We have investigated the central metabolism of this bacterium using both in vitro enzyme assays and 13C-based flux analysis to provide insights into the physiological properties of this extremophile and explore its metabolism for bio-ethanol or other bioprocess applications. Our findings show that glucose metabolism in G. thermoglucosidasius M10EXG proceeds via glycolysis, the pentose phosphate pathway, and the TCA cycle; the Entner?Doudoroff pathway and transhydrogenase activity were not detected. Anaplerotic reactions (including the glyoxylate shunt, pyruvate carboxylase, and phosphoenolpyruvate carboxykinase) were active, but fluxes through those pathways could not be accuratelydetermined using amino acid labeling. When growth conditions were switched from aerobic to micro-aerobic conditions, fluxes (based on a normalized glucose uptake rate of 100 units (g DCW)-1 h-1) through the TCA cycle and oxidative pentose phosphate pathway were reduced from 64+-3 to 25+-2 and from 30+-2 to 19+-2, respectively. The carbon flux under micro-aerobic growth was directed formate. Under fully anerobic conditions, G. thermoglucosidasius M10EXG used a mixed acid fermentation process and exhibited a maximum ethanol yield of 0.38+-0.07 mol mol-1 …
Date: January 20, 2009
Creator: Tang, Yinjie J.; Sapra, Rajat; Joyner, Dominique; Hazen, Terry C.; Myers, Samuel; Reichmuth, David et al.
Object Type: Article
System: The UNT Digital Library
Nuclear Hydrogen for Peak Electricity Production and Spinning Reserve (open access)

Nuclear Hydrogen for Peak Electricity Production and Spinning Reserve

Nuclear energy can be used to produce hydrogen. The key strategic question is this: ''What are the early markets for nuclear hydrogen?'' The answer determines (1) whether there are incentives to implement nuclear hydrogen technology today or whether the development of such a technology could be delayed by decades until a hydrogen economy has evolved, (2) the industrial partners required to develop such a technology, and (3) the technological requirements for the hydrogen production system (rate of production, steady-state or variable production, hydrogen purity, etc.). Understanding ''early'' markets for any new product is difficult because the customer may not even recognize that the product could exist. This study is an initial examination of how nuclear hydrogen could be used in two interconnected early markets: the production of electricity for peak and intermediate electrical loads and spinning reserve for the electrical grid. The study is intended to provide an initial description that can then be used to consult with potential customers (utilities, the Electric Power Research Institute, etc.) to better determine the potential real-world viability of this early market for nuclear hydrogen and provide the starting point for a more definitive assessment of the concept. If this set of applications is …
Date: January 20, 2005
Creator: Forsberg, Charles W.
Object Type: Report
System: The UNT Digital Library
Improving Consistency of Performance Assessments in the Doe Complex (open access)

Improving Consistency of Performance Assessments in the Doe Complex

The low-level waste (LLW) performance assessment (PA) process has been traditionally focused on disposal facilities at a few United States Department of Energy (USDOE) sites and commercial disposal facilities. In recent years, there has been a dramatic increase in the scope of the use of PA-like modeling approaches, involving multiple activities, facilities, contractors and regulators. The scope now includes, for example: (1) National Environmental Policy Act (NEPA) assessments, (2) CERCLA disposal cells, (3) Waste Determinations and High-Level Waste (HLW) Closure activities, (4) Potential on-site disposal of Transuranic (TRU) waste, and (5) In-situ decommissioning (including potential use of existing facilities for disposal). The dramatic increase in the variety of activities requiring more detailed modeling has resulted in a similar increase in the potential for inconsistency in approaches both at a site and complexwide scale. This paper includes a summary of USDOE Environmental Management (EM) sponsored initiatives and activities for improved consistency. New initiatives entitled the Performance Assessment Community of Practice and Performance Assessment Assistance Team are also introduced.
Date: January 20, 2009
Creator: Seitz, R. & Elmer Wilhite, E.
Object Type: Article
System: The UNT Digital Library
Final report SBIR Phase II. High current density,(Jc), low AC loss, low cost, Internal-Tin Superconductor (open access)

Final report SBIR Phase II. High current density,(Jc), low AC loss, low cost, Internal-Tin Superconductor

Final report of SBIR to develop an economical process that can produce the best material for high field magnets to be used in the next generation of accelerators
Date: January 20, 2009
Creator: Gregory, Eric
Object Type: Report
System: The UNT Digital Library
Stochastic Boundary, Diffusion, Emittance Growth and Lifetime calculation for the RHIC e-lens (open access)

Stochastic Boundary, Diffusion, Emittance Growth and Lifetime calculation for the RHIC e-lens

To compensate the large tune shift and tune spread generated by the head-on beam-beam interactions in polarized proton operation in the Relativistic Heavy Ion Collider (RHIC), a low energy electron beam with proper Gaussian transverse profiles was proposed to collide head-on with the proton beam. In this article, using a modified version of SixTrack [1], we investigate stability of the single particle in the presence of head-on beam-beam compensation. The Lyapunov exponent and action diffusion are calculated and compared between the cases without and with beam-beam compensation for two different working points and various bunch intensities. Using the action diffusion results the emittance growth rate and lifetime of the proton beam is also estimated for the different scenarios.
Date: January 20, 2009
Creator: Abreu,N.P.; Fischer, W.; Luo, Y. & Robert-Demolaize, G.
Object Type: Report
System: The UNT Digital Library
Hanford Site Environmental Surveillance Master Sampling Schedule for Calendar Year 2009 (open access)

Hanford Site Environmental Surveillance Master Sampling Schedule for Calendar Year 2009

Environmental surveillance of the Hanford Site and surrounding areas is conducted by the Pacific Northwest National Laboratory for the U.S. Department of Energy. Sampling is conducted to evaluate levels of radioactive and nonradioactive pollutants in the Hanford environs, as required in DOE Order 450.1 and DOE Order 5400.5. This document contains the calendar year 2009 schedule for the routine collection of samples for the Surface Environmental Surveillance Project and Drinking Water Monitoring Project. Each section includes sampling locations, sampling frequencies, sample types, and analyses to be performed. In some cases, samples are scheduled on a rotating basis. If a sample will not be collected in 2009, the anticipated year for collection is provided. Maps showing approximate sampling locations are included for media scheduled for collection in 2009.
Date: January 20, 2009
Creator: Bisping, Lynn E.
Object Type: Report
System: The UNT Digital Library
CH3-ReO3 on gamma-Al2O3: understanding its structure, initiation,and reactivity in olefin metathesis (open access)

CH3-ReO3 on gamma-Al2O3: understanding its structure, initiation,and reactivity in olefin metathesis

Me-ReO3 on gamma-alumina: understanding the structure, theinitiation and thereactivity of a highly active olefin metathesiscatalyst Heterolytic splitting of the C-H bond of the methyl group ofCH3ReO3 on AlsO reactive sites of alumina as a way to generate the activesite of CH3ReO3 supported on gamma-Al203.
Date: January 20, 2007
Creator: Salameh, Alain; Joubert, Jerome; Baudouin, Anne; Lukens, Wayne; Delbecq, Francoise; Sautet, Philippe et al.
Object Type: Article
System: The UNT Digital Library

Concentrating Photovoltaics

Solar is growing rapidly, and the concentrating photovoltaics industry-both high- and low-concentration cell approaches-may be ready to ramp production in 2009.
Date: January 20, 2009
Creator: Kurtz, S.
Object Type: Presentation
System: The UNT Digital Library
2005 White Paper on Institutional Capability Computing Requirements (open access)

2005 White Paper on Institutional Capability Computing Requirements

This paper documents the need for a significant increase in the computing infrastructure provided to scientists working in the unclassified domains at Lawrence Livermore National Laboratory (LLNL). This need could be viewed as the next step in a broad strategy outlined in the January 2002 White Paper (UCRL-ID-147449) that bears essentially the same name as this document. Therein we wrote: 'This proposed increase could be viewed as a step in a broader strategy linking hardware evolution to applications development that would take LLNL unclassified computational science to a position of distinction if not preeminence by 2006.' This position of distinction has certainly been achieved. This paper provides a strategy for sustaining this success but will diverge from its 2002 predecessor in that it will: (1) Amplify the scientific and external success LLNL has enjoyed because of the investments made in 2002 (MCR, 11 TF) and 2004 (Thunder, 23 TF). (2) Describe in detail the nature of additional investments that are important to meet both the institutional objectives of advanced capability for breakthrough science and the scientists clearly stated request for adequate capacity and more rapid access to moderate-sized resources. (3) Put these requirements in the context of an overall strategy …
Date: January 20, 2006
Creator: Carnes, B; McCoy, M & Seager, M
Object Type: Report
System: The UNT Digital Library
MEASUREMENT OF WIND SPEED FROM COOLING LAKE THERMAL IMAGERY (open access)

MEASUREMENT OF WIND SPEED FROM COOLING LAKE THERMAL IMAGERY

The Savannah River National Laboratory (SRNL) collected thermal imagery and ground truth data at two commercial power plant cooling lakes to investigate the applicability of laboratory empirical correlations between surface heat flux and wind speed, and statistics derived from thermal imagery. SRNL demonstrated in a previous paper [1] that a linear relationship exists between the standard deviation of image temperature and surface heat flux. In this paper, SRNL will show that the skewness of the temperature distribution derived from cooling lake thermal images correlates with instantaneous wind speed measured at the same location. SRNL collected thermal imagery, surface meteorology and water temperatures from helicopters and boats at the Comanche Peak and H. B. Robinson nuclear power plant cooling lakes. SRNL found that decreasing skewness correlated with increasing wind speed, as was the case for the laboratory experiments. Simple linear and orthogonal regression models both explained about 50% of the variance in the skewness - wind speed plots. A nonlinear (logistic) regression model produced a better fit to the data, apparently because the thermal convection and resulting skewness are related to wind speed in a highly nonlinear way in nearly calm and in windy conditions.
Date: January 20, 2009
Creator: Garrett, A; Robert Kurzeja, R; Eliel Villa-Aleman, E; Cary Tuckfield, C & Malcolm Pendergast, M
Object Type: Article
System: The UNT Digital Library
Electrical properties of a-C:Mo films produced by dual-cathode filtered cathodic arc plasma deposition (open access)

Electrical properties of a-C:Mo films produced by dual-cathode filtered cathodic arc plasma deposition

Molybdenum-containing amorphous carbon (a-C:Mo) thin films were prepared using a dual-cathode filtered cathodic arc plasma source with a molybdenum and a carbon (graphite) cathode. The Mo content in the films was controlled by varying the deposition pulse ratio of Mo and C. Film sheet resistance was measured in situ at process temperature, which was close to room temperature, as well as ex situ as a function of temperature (300-515 K) in ambient air. Film resistivity and electrical activation energy were derived for different Mo and C ratios and substrate bias. Film thickness was in the range 8-28 nm. Film resistivity varied from 3.55x10-4 Omega m to 2.27x10-6 Omega m when the Mo/C pulse ratio was increased from 0.05 to 0.4, with no substrate bias applied. With carbon-selective bias, the film resistivity was in the range of 4.59x10-2 and 4.05 Omega m at a Mo/C pulse ratio of 0.05. The electrical activation energy decreased from 3.80x10-2 to 3.36x10-4 eV when the Mo/C pulse ratio was increased in the absence of bias, and from 0.19 to 0.14 eV for carbon-selective bias conditions. The resistivity of the film shifts systematically with the amounts of Mo and upon application of substrate bias voltage. The …
Date: January 20, 2008
Creator: Sansongsiri, Sakon; Anders, Andre & Yodsombat, Banchob
Object Type: Article
System: The UNT Digital Library