"When the Safety System Fails the Worker: Did We Do Our Job?...a Case Study" (open access)

"When the Safety System Fails the Worker: Did We Do Our Job?...a Case Study"

None
Date: May 12, 2006
Creator: McConnell, S
Object Type: Article
System: The UNT Digital Library
TOUGH+/GasH20 study of the effects of a heat source buried in theMartian permafrost (open access)

TOUGH+/GasH20 study of the effects of a heat source buried in theMartian permafrost

We use TOUGH+/GasH2O to study the effects of a heat sourceburied in the Martian permafrost to evaluate the possibility ofestablishing a wet zone of liquid water, in which terrestrialmicroorganisms could survive and multiply. Analysis of the problemindicates that (1) only a limited permafrost volume (not exceeding 0.35 min radius) is affected, (2) a "wet" zone with limited amounts of liquidwater de-velops (not exceeding 8 and 0.7 kg for a 250 W and a 62.5 Wsource, respectively), (3) the wet zone per-sists for a long time,becomes practically stationary after t = 20 sols because of venting intothe Martian atmosphere, and its thickness is limited and decreases slowlyover time, (4) a "dry" zone (where SG>0.9) evolves, continues toexpand (albeit slowly) with time, but its extent remains limited, and (5)the ice front surrounding the wet zone is self-sharpening. For a range ofinitial conditions investigated, evolution of the liquid water massoccurs at approximately the same rate, reaches roughly the same maximum,and occurs at about the same time (10 to 20 sols; 1 sol = 24.39hours).
Date: May 12, 2006
Creator: Moridis, George J. & Pruess, Karsten
Object Type: Article
System: The UNT Digital Library
New developments for the site-specific attachment of protein to surfaces (open access)

New developments for the site-specific attachment of protein to surfaces

Protein immobilization on surfaces is of great importance in numerous applications in biology and biophysics. The key for the success of all these applications relies on the immobilization technique employed to attach the protein to the corresponding surface. Protein immobilization can be based on covalent or noncovalent interaction of the molecule with the surface. Noncovalent interactions include hydrophobic interactions, hydrogen bonding, van der Waals forces, electrostatic forces, or physical adsorption. However, since these interactions are weak, the molecules can get denatured or dislodged, thus causing loss of signal. They also result in random attachment of the protein to the surface. Site-specific covalent attachment of proteins onto surfaces, on the other hand, leads to molecules being arranged in a definite, orderly fashion and uses spacers and linkers to help minimize steric hindrances between the protein surface. This work reviews in detail some of the methods most commonly used as well as the latest developments for the site-specific covalent attachment of protein to solid surfaces.
Date: May 12, 2005
Creator: Camarero, J A
Object Type: Article
System: The UNT Digital Library
Polychlorinated Biphenyls (PCBs) in Catfish and Carp Collected from the Rio Grande Upstream and Downstream of Los Alamos National Laboratory: Revision 1 (open access)

Polychlorinated Biphenyls (PCBs) in Catfish and Carp Collected from the Rio Grande Upstream and Downstream of Los Alamos National Laboratory: Revision 1

Concern has existed for years that the Los Alamos National Laboratory (LANL), a complex of nuclear weapons research and support facilities, has released polychlorinated biphenyls (PCBs) to the environment that may have reached adjacent bodies of water through canyons that connect them. In 1997, LANL's Ecology Group began measuring PCBs in fish in the Rio Grande upstream and downstream of ephemeral streams that cross LANL and later began sampling fish in Abiquiu and Cochiti reservoirs, which are situated on the Rio Chama and Rio Grande upstream and downstream of LANL, respectively. In 2002, we electroshocked channel catfish (Ictalurus punctatus) and common carp (Carpiodes carpio) in the Rio Grande upstream and downstream of LANL and analyzed fillets for PCB congeners. We also sampled soils along the Rio Chama and Rio Grande drainages to discern whether a background atmospheric source of PCBs that could impact surface water adjacent to LANL might exist. Trace concentrations of PCBs measured in soil (mean = 4.7E-05 {micro}g/g-ww) appear to be from background global atmospheric sources, at least in part, because the bimodal distribution of low-chlorinated PCB congeners and mid-chlorinated PCB congeners in the soil samples is interpreted to be typical of volatilized PCB congeners that are …
Date: May 12, 2008
Creator: Fresquez, Gilbert J. Gonzales Philip R.
Object Type: Report
System: The UNT Digital Library
Combinatorial Screening of Advanced Scintillators for High Resolution X-ray Detectors (open access)

Combinatorial Screening of Advanced Scintillators for High Resolution X-ray Detectors

The lack of efficient scintillators is a major problem for developing powerful x-ray detectors that are widely used in homeland security, industrial and scientific research. Intematix has developed and applied a high throughput screening process and corresponding crystal growth technology to significantly speed up the discovery process for new efficient scintillators. As a result, Intematix has invented and fabricated three new scintillators both in powder and bulk forms, which possess promising properties such as better radiation hardness and better matching for silicon diode.
Date: May 12, 2008
Creator: Cheng, Shifan; Tao, Dejie; Lynch, Michael; Yuan, Xianglong & Li, Yiqun
Object Type: Report
System: The UNT Digital Library
Combustion of Coal Using Chemical Looping Oxygen Carriers (open access)

Combustion of Coal Using Chemical Looping Oxygen Carriers

Slide presentation only - No abstract supplied
Date: May 12, 2008
Creator: Tian, Hanjing; Simonyi, Thomas; Siriwardane, R.V. & Richards, G.A.
Object Type: Article
System: The UNT Digital Library
Design and Sensor-Based COntrol for Hyper-Redundant Mechanisms (open access)

Design and Sensor-Based COntrol for Hyper-Redundant Mechanisms

Toxic materials in DOE sites pose a significant threat to DOE personnel who must inspect these locations. Working in confined spaces further complicates the situation especially when the workers must wear heavy and cumbersome protective suits.
Date: May 12, 2006
Creator: Choset, Howie
Object Type: Report
System: The UNT Digital Library
Verification of high-order mixed FEM solution of transient Magnetic diffusion problems (open access)

Verification of high-order mixed FEM solution of transient Magnetic diffusion problems

We develop and present high order mixed finite element discretizations of the time dependent electromagnetic diffusion equations for solving eddy current problems on 3D unstructured grids. The discretizations are based on high order H(grad), H(curl) and H(div) conforming finite element spaces combined with an implicit and unconditionally stable generalized Crank-Nicholson time differencing method. We develop three separate electromagnetic diffusion formulations, namely the E (electric field), H (magnetic field) and the A-{phi} (potential) formulations. For each formulation, we also provide a consistent procedure for computing the secondary variables F (current flux density) and B (magnetic flux density), as these fields are required for the computation of electromagnetic force and heating terms. We verify the error convergence properties of each formulation via a series of numerical experiments on canonical problems with known analytic solutions. The key result is that the different formulations are equally accurate, even for the secondary variables J and B, and hence the choice of which formulation to use depends mostly upon relevance of the Natural and Essential boundary conditions to the problem of interest. In addition, we highlight issues with numerical verification of finite element methods which can lead to false conclusions on the accuracy of the methods.
Date: May 12, 2005
Creator: Rieben, R. & White, D. A.
Object Type: Article
System: The UNT Digital Library
Small-Column Ion-Exchange Alternative to Remove 137Cs from Low-Curie Salt Waste: Summary of Phase 1 (open access)

Small-Column Ion-Exchange Alternative to Remove 137Cs from Low-Curie Salt Waste: Summary of Phase 1

A Small-Column Ion-Exchange (SCIX) system is being evaluated for removing cesium from the Type 2 and/or Type 3 dissolved saltcake wastes at the Savannah River Site (SRS) to ensure that the dissolved saltcake meets the waste acceptance criteria at the Saltstone Facility. Both crystalline silicotitanate (CST) and IONSIV{trademark} IE-96 zeolite were evaluated as the ion-exchange media. The accelerated alternative, using CST in the SCIX, could save as much as $3 billion in operating and storage costs and {approx}20 years in processing time compared to the current baseline. With its proven high cesium-loading capacity for the expected dissolved saltcake compositions and temperatures, CST is the preferred sorbent for SCIX. The low-cost alternative sorbent, zeolite, greatly increases the volume of sorbent required because of its much lower cesium-loading capacity. Thus, zeolite greatly increases the cost for the alternative, mainly because of the increased number of Defense Waste Processing Facility canisters required to dispose of the loaded sorbent (potentially over 7000 for zeolite, compared with <500 for CST). The models previously developed for predicting cesium loading on CST compared favorably with laboratory measurements of equilibrium distribution ratios and column loading performance using dissolved saltcake simulants. These models predict that a column of 432 …
Date: May 12, 2004
Creator: Walker, J. F. Jr.
Object Type: Report
System: The UNT Digital Library
DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS (open access)

DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS

The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. The largest applications are those which support metals smelting, such as anodes for aluminum smelting and electrodes for arc furnaces. Other carbon products include materials used in creating fuels for the Direct Carbon Fuel Cell, metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, coking and composite fabrication continued using coal-derived samples. These samples were tested in direct carbon fuel cells. Methodology was refined for determining the aromatic character of hydro treated liquid, based on Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FTIR). Tests at GrafTech International showed that binder pitches produced using the WVU solvent extraction protocol can result in acceptable graphite electrodes for use in arc furnaces. These tests were made at the pilot scale.
Date: May 12, 2006
Creator: Kennel, Elliot B.; Bergen, R. Michael; Carpenter, Stephen P.; Dadyburjor, Dady; Katakdaunde, Manoj; Magean, Liviu et al.
Object Type: Report
System: The UNT Digital Library
Vacuum-ultraviolet (VUV) photoionization of small methanol and methanol-water clusters (open access)

Vacuum-ultraviolet (VUV) photoionization of small methanol and methanol-water clusters

In this work we report on thevacuum-ultraviolet (VUV) photoionization of small methanol and methanol-water clusters. Clusters of methanol with water are generated via co-expansion of the gas phase constituents in a continuous supersonic jet expansion of methanol and water seeded in Ar. The resulting clusters are investigated by single photon ionization with tunable vacuumultraviolet synchrotron radiation and mass analyzed using reflectron mass spectrometry. Protonated methanol clusters of the form (CH3OH)nH + (n=1-12) dominate the mass spectrum below the ionization energy of the methanol monomer. With an increase in water concentration, small amounts of mixed clusters of the form (CH3OH)n(H2O)H + (n=2-11) are detected. The only unprotonated species observed in this work are the methanol monomer and dimer. Appearance energies are obtained from the photoionization efficiency (PIE) curves for CH3OH +, (CH 3OH)2 +, (CH3OH)nH + (n=1-9), and (CH 3OH)n(H2O)H + (n=2-9 ) as a function of photon energy. With an increase in the water content in the molecular beam, there is an enhancement of photoionization intensity for methanol dimer and protonated methanol monomer at threshold. These results are compared and contrasted to previous experimental observations.
Date: May 12, 2008
Creator: Ahmed, Musahid; Ahmed, Musahid; Wilson, Kevin R.; Belau, Leonid & Kostko, Oleg
Object Type: Article
System: The UNT Digital Library
Pilot Demonstration of Technology for the Production of High Value Materials from the Ultra-Fine (PM 2.5) Fraction of Coal Combustion Ash (open access)

Pilot Demonstration of Technology for the Production of High Value Materials from the Ultra-Fine (PM 2.5) Fraction of Coal Combustion Ash

During this reporting period, efforts focused on improving our understanding of the basic operating principles of the lamella classifier. It was determined from testing that product grade is primarily a function of the classifier configuration and operation and the feed grade has relatively minor influence. Additionally, within the range of the testing conducted, the feed density did not seem to have an impact of the yield. Thus, the product composition will not be strongly influenced by the variability of the feed, an important consideration for heterogeneous ponded fly ash. Three types of chemically and functionally different thermoplastic polymers have been chosen for evaluation with the fly ash derived filler: high density polyethylene, thermoplastic elastomer, and polyethylene terphthalate. The selections were based on volumes consumed in commercial and recycled products. The reference filler selected for comparison was 3 {micro}m calcium carbonate, a material which is commonly used with all three types of polymers. A procedure to prepare filled polymers has been developed and most ({approx}80%) of the polymer/filler blends have been prepared. Selected samples of filled polymers were subjected to SEM analysis to verify that the fly ash derived filler and the calcium carbonate were well dispersed. A stainless steel mold …
Date: May 12, 2006
Creator: Robl, T.L.; Groppo, J.G. & Rathbone, Robert
Object Type: Report
System: The UNT Digital Library
Development and analysis of a compact low-conversion ratio fast burner reactor. (open access)

Development and analysis of a compact low-conversion ratio fast burner reactor.

This report explores design options for compact fast burner reactors that can achieve low conversion ratios. Operational characteristics and whole-core reactivity coefficients are generated and contrasted with low conversion ratio designs of previous studies. A compact core point design is then selected and detailed reactivity coefficients are displayed and discussed. The effectiveness of fast spectrum systems for actinide transmutation has been well documented. The key advantage of the fast spectrum resides in the severely reduced capture/fission ratios. this inhibits the production of the higher actinides that dominate the long-term radiotoxicity of nuclear waste. In conventional fast burner studies, the transmutation rate was limited by constraints placed on the fuel composition. In an earlier phase of this study the entire range of fuel compositions (including non-uranium fuel) was explored to assess the performance and safety limits of fast burner reactor systems. In this report, similar fuel compositions are utilized for application in compact configurations to achieve conversion ratios below 0.5.
Date: May 12, 2006
Creator: Smith, M. A. & Hill, R. N.
Object Type: Report
System: The UNT Digital Library
Final Hazard Categorization for the Remediation of Six 300-FF-2 Operable Unit Solid Waste Burial Grounds (open access)

Final Hazard Categorization for the Remediation of Six 300-FF-2 Operable Unit Solid Waste Burial Grounds

This report provides the final hazard categorization for the remediation of six 300-FF-2 Operable Unit Burial Grounds, the 618-1, 618-2, 618-3, 618-7, 618-8, and 618-13 sites.
Date: May 12, 2008
Creator: Ludowise, J. D. & Vialetti, K. L.
Object Type: Report
System: The UNT Digital Library
Response of California temperature to regional anthropogenic aerosol changes (open access)

Response of California temperature to regional anthropogenic aerosol changes

In this paper, we compare constructed records of concentrations of black carbon (BC)--an indicator of anthropogenic aerosols--with observed surface temperature trends in California. Annual average BC concentrations in major air basins in California significantly decreased after about 1990, coincident with an observed statewide surface temperature increase. Seasonal aerosol concentration trends are consistent with observed seasonal temperature trends. These data suggest that the reduction in anthropogenic aerosol concentrations contributed to the observed surface temperature increase. Conversely, high aerosol concentrations may lower surface temperature and partially offset the temperature increase of greenhouse gases.
Date: May 12, 2008
Creator: Kirchstetter, Thomas; Novakov, T.; Kirchstetter, T.W.; Menon, S. & Aguiar, J.
Object Type: Article
System: The UNT Digital Library

DOE's Hydrogen Fuel Cell Activities: Developing Technology and Validating it through Real-World Evaluation

Presentation prepared for the May 12, 2008 Alternative Fuels and Vehicles Conference that describes DOE's current hydrogen fuel cell technology validation projects.
Date: May 12, 2008
Creator: Wipke, K.; Sprik, S.; Kurtz, J. & Garbak, J.
Object Type: Presentation
System: The UNT Digital Library
Beam Measurements and Upgrade at BL 7.2, the Second DiagnosticsBeamline of the Advanced Light Source (open access)

Beam Measurements and Upgrade at BL 7.2, the Second DiagnosticsBeamline of the Advanced Light Source

Beamline 7.2 of the Advanced Light Source (ALS) at theLawrence Berkeley National Laboratory (LBNL) is a beam diagnostics systemthat uses the synchrotron radiation emitted by a dipole magnet. Itconsists of two branches; in the first one the x-ray portion of theradiation is used in a pinhole camera system for measuring the transverseprofile of the beam. The second branch is equipped with an x-ray beamposition monitor (BPM) and with a multipurpose port where the visible andthe far-infrared part of the radiation can be used for variousapplications such as bunch length measurements and IR coherentsynchrotron radiation experiments. The pinhole system has been operatingsuccessfully since the end of 2003. The installation of the second branchhas been completed recently and the results of its commissioning arepresented in this paper together with examples of beam measurementsperformed at BL 7.2.
Date: May 12, 2005
Creator: Scarvie, Tom; Sannibale, Fernando; Biocca, Alan; Kelez, Nicholas; Martin, Michael C.; Nishimura, Toshiro et al.
Object Type: Article
System: The UNT Digital Library
Integrating Data Clustering and Visualization for the Analysis of 3D Gene Expression Data (open access)

Integrating Data Clustering and Visualization for the Analysis of 3D Gene Expression Data

The recent development of methods for extracting precise measurements of spatial gene expression patterns from three-dimensional (3D) image data opens the way for new analyses of the complex gene regulatory networks controlling animal development. We present an integrated visualization and analysis framework that supports user-guided data clustering to aid exploration of these new complex datasets. The interplay of data visualization and clustering-based data classification leads to improved visualization and enables a more detailed analysis than previously possible. We discuss (i) integration of data clustering and visualization into one framework; (ii) application of data clustering to 3D gene expression data; (iii) evaluation of the number of clusters k in the context of 3D gene expression clustering; and (iv) improvement of overall analysis quality via dedicated post-processing of clustering results based on visualization. We discuss the use of this framework to objectively define spatial pattern boundaries and temporal profiles of genes and to analyze how mRNA patterns are controlled by their regulatory transcription factors.
Date: May 12, 2008
Creator: Data Analysis and Visualization (IDAV) and the Department of Computer Science, University of California, Davis, One Shields Avenue, Davis CA 95616, USA,; nternational Research Training Group ``Visualization of Large and Unstructured Data Sets,'' University of Kaiserslautern, Germany; Computational Research Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720, USA; Genomics Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley CA 94720, USA; Life Sciences Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley CA 94720, USA,; Computer Science Division,University of California, Berkeley, CA, USA, et al.
Object Type: Article
System: The UNT Digital Library
Shape-selective catalysts for Fischer-Tropsch chemistry : iron-containing particulate catalysts. Activity report : January 1, 2001 - December 31, 2004. (open access)

Shape-selective catalysts for Fischer-Tropsch chemistry : iron-containing particulate catalysts. Activity report : January 1, 2001 - December 31, 2004.

Argonne National Laboratory is carrying out a research program to create, prepare, and evaluate catalysts to promote Fischer-Tropsch (FT) chemistry--specifically, the reaction of hydrogen with carbon monoxide to form long-chain hydrocarbons. In addition to needing high activity, it is desirable that the catalysts have high selectivity and stability with respect to both mechanical strength and aging properties. It is desired that selectivity be directed toward producing diesel fraction components and avoiding excess yields of both light hydrocarbons and heavy waxes. The goal is to produce shape-selective catalysts that have the potential to limit the formation of longchain products and yet retain the active metal sites in a protected 'cage'. This cage also restricts their loss by attrition during use in slurry-bed reactors. The first stage of this program was to prepare and evaluate iron-containing particulate catalysts. This activity report centers upon this first stage of experimentation with particulate FT catalysts. (For reference, a second experimental stage is under way to prepare and evaluate active FT catalysts formed by atomic-layer deposition [ALD] of active components on supported membranes.) To date, experimentation has centered upon the evaluation of a sample of iron-based, spray-dried catalyst prepared by B.H. Davis of the Center of …
Date: May 12, 2006
Creator: Cronauer, D. & Engineering, Chemical
Object Type: Report
System: The UNT Digital Library
Detection of Atmospheric Muon Neutrinoswith the IceCube 9-String Detector (open access)

Detection of Atmospheric Muon Neutrinoswith the IceCube 9-String Detector

The IceCube neutrino detector is a cubic kilometer TeV to PeV neutrino detector under construction at the geographic South Pole. The dominant population of neutrinos detected in IceCube is due to meson decay in cosmic-ray air showers. These atmospheric neutrinos are relatively well understood and serve as a calibration and verification tool for the new detector. In 2006, the detector was approximately 10% completed, and we report on data acquired from the detector in this configuration. We observe an atmospheric neutrino signal consistent with expectations, demonstrating that the IceCube detector is capable of identifying neutrino events. In the first 137.4 days of livetime, 234 neutrino candidates were selected with an expectation of 211 {+-} 76.1(syst.) {+-} 14.5(stat.) events from atmospheric neutrinos.
Date: May 12, 2007
Creator: Collaboration, IceCube; Klein, Spencer & Achterberg, A.
Object Type: Article
System: The UNT Digital Library
Linear Model for Non Isosceles Absorbers. (open access)

Linear Model for Non Isosceles Absorbers.

Previous analyses have assumed that wedge absorbers are triangularly shaped with equal angles for the two faces. In this case, to linear order, the energy loss depends only on the position in the direction of the face tilt, and is independent of the incoming angle. One can instead construct an absorber with entrance and exit faces facing rather general directions. In this case, the energy loss can depend on both the position and the angle of the particle in question. This paper demonstrates that and computes the effect to linear order.
Date: May 12, 2003
Creator: Berg, J. S.
Object Type: Article
System: The UNT Digital Library
DESIGN, CONSTRUCTION, AND STATUS OF ALL NIOBIUM SUPERCONDUCTING PHOTOINJECTOR AT BNL. (open access)

DESIGN, CONSTRUCTION, AND STATUS OF ALL NIOBIUM SUPERCONDUCTING PHOTOINJECTOR AT BNL.

We present here the design and construction of an all niobium superconducting RF injector to generate high average current, high brightness electron beam. A 1/2 cell superconducting cavity has been designed, built, and tested. A cryostat has been built to cool the cavity to {approx}2 K. The RF system can deliver up to 500 W at 1.3 GHz to the cavity. A mode-locked Nd:YVO{sub 4} laser, operating at 266 nm with 0.15 W average power, phase locked to the RF, will irradiate a laser cleaned Nb surface at the back wall of the cavity. Description of critical components and their status are presented in the paper. Based on DC measurements, QE of up to 10{sup 4} can be expected from such cavity.
Date: May 12, 2004
Creator: SRINIVASAN-RAO,T. BEN-ZVI,I. BURRILL,A. CITVER,G. ET AL.
Object Type: Article
System: The UNT Digital Library
ACTION AND PHASE ANALYSIS TO DETERMINE SEXTUPOLE ERRORS IN RHIC AND THE SPS. (open access)

ACTION AND PHASE ANALYSIS TO DETERMINE SEXTUPOLE ERRORS IN RHIC AND THE SPS.

Success in the application of the action and phase analysis to find linear errors at RHIC Interaction Regions [1] has encouraged the creation of a technique based on the action and phase analysis to find non linear errors. In this paper we show the first attempt to measure the sextupole components at RHIC interaction regions using the action and phase method. Experiments done by intentionally activating sextupoles in RHIC and in SPS [2] will also be analyzed with this method. First results have given values for the sextupole errors that at least have the same order of magnitude as the values found by an alternate technique during the RHIC 2001 run [3].
Date: May 12, 2003
Creator: Cardona, J.; Peggs, S.; Satogata, T. & Tomas, R.
Object Type: Article
System: The UNT Digital Library
ELECTRON CLOUD AND PRESSURE RISE SIMULATIONS FOR RHIC. (open access)

ELECTRON CLOUD AND PRESSURE RISE SIMULATIONS FOR RHIC.

Beam induced electron multipacting may be among the main reasons for the vacuum pressure rise when circulating high intensity ion and proton beams in RHIC. Latest simulation results are benchmarked with recent experimental observations for RHIC, and compared to other general computer codes. The influence of the electron multipacting to the vacuum properties is also discussed.
Date: May 12, 2003
Creator: IRISO-ARIZ,U. BLASKIEWICZ,M. DREES,A. FISCHER,W. PEGGS,S. TRBOJEVIC,D.
Object Type: Article
System: The UNT Digital Library