Insulated Pressure Vessels for Vehicular Hydrogen Storage: Analysis and Performance Evaluation (open access)

Insulated Pressure Vessels for Vehicular Hydrogen Storage: Analysis and Performance Evaluation

Insulated pressure vessels are cryogenic-capable pressure vessels that can be fueled with liquid hydrogen (LH{sub 2}) or ambient-temperature compressed hydrogen (CH{sub 2}). Insulated pressure vessels offer the advantages of liquid hydrogen tanks (low weight and volume), with reduced disadvantages (fuel flexibility, lower energy requirement for hydrogen liquefaction and reduced evaporative losses). The work described here is directed at verifying that commercially available pressure vessels can be safely used to store liquid hydrogen. The use of commercially available pressure vessels significantly reduces the cost and complexity of the insulated pressure vessel development effort. This paper describes a series of tests that have been done with aluminum-lined, fiber-wrapped vessels to evaluate the damage caused by low temperature operation. All analysis and experiments to date indicate that no significant damage has resulted. Required future tests are described that will prove that no technical barriers exist to the safe use of aluminum-fiber vessels at cryogenic temperatures. Future activities also include a demonstration project in which the insulated pressure vessels will be installed and tested on two vehicles. A draft standard will also be generated for obtaining certification for insulated pressure vessels.
Date: June 26, 2001
Creator: Aceves, S. M.; Martinez-Frias, J.; Garcia-Villazana, O. & Espinosa-Loza, F.
Object Type: Article
System: The UNT Digital Library
Mechanical Engineering Safety Note PEPC Spreader Bar Assembly (open access)

Mechanical Engineering Safety Note PEPC Spreader Bar Assembly

The PEPC Spreader Bar Assembly consists of a spreader bar that will be attached to the PEPC Cell Housing or the Midplane Transportation Fixture during operation. While in use in the OAB (Optics Assembly Building), the Spreader Bar Assembly will be manipulated by the NOID (New Optics Insertion Device). The other critical components of the assembly are the three angular contact bearing swivels that attach the spreader bar to the lifting mechanism and the corner clamps which are used to capture the Cell Housing.
Date: August 26, 2001
Creator: Mason, D.
Object Type: Report
System: The UNT Digital Library
Recent Results from EBIT-II Using a Spare Astro-E Microcalorimeter (open access)

Recent Results from EBIT-II Using a Spare Astro-E Microcalorimeter

A spare NASA/GSFC Astro-E microcalorimeter has been installed, tested, and run successfully on EBIT-II at the Lawrence Livermore National Laboratory. A brief overview of results including measurements by the microcalorimeter of absolute excitation cross sections, time dependent spectra, and spectra as a function of Maxwellian temperature are discussed.
Date: June 26, 2001
Creator: Brown, G V; Behar, E; Beiersdorfer, P; Boyce, K R; Chen, H; Gendreau, K C et al.
Object Type: Article
System: The UNT Digital Library
Effect of multiple and delayed jet impact and penetration on concrete target borehole diameter (open access)

Effect of multiple and delayed jet impact and penetration on concrete target borehole diameter

The effect of multiple and delayed jet impact and penetration on the borehole diameter in concrete targets is discussed in this paper. A first-order principle of shaped-charge jet penetration is that target hole volume is proportional to the energy deposited in the target by the jet. This principle is the basis for the relation that target borehole diameter at any depth along the penetration path is proportional to the jet energy deposited in the target at that location. Our current research shows that the 'jet energy per unit hole volume constant' for concrete can be substantially altered by the use of multiple and delayed jet impacts. It has been shown that enhanced entrance crater formation results from the simultaneous impact and penetration of three shaped-charge jets. We now demonstrate that enhanced borehole diameter is also observed by the simultaneous impact and penetration of multiple shaped-charge jets followed by the delayed impact and penetration of a single shaped-charge jet.
Date: January 26, 2001
Creator: Murphy, M J; Baum, D W; Kuklo, R M & Simonson, S C
Object Type: Article
System: The UNT Digital Library
Creating Ensembles of Decision Trees Through Sampling (open access)

Creating Ensembles of Decision Trees Through Sampling

Recent work in classification indicates that significant improvements in accuracy can be obtained by growing an ensemble of classifiers and having them vote for the most popular class. This paper focuses on ensembles of decision trees that are created with a randomized procedure based on sampling. Randomization can be introduced by using random samples of the training data (as in bagging or boosting) and running a conventional tree-building algorithm, or by randomizing the induction algorithm itself. The objective of this paper is to describe the first experiences with a novel randomized tree induction method that uses a sub-sample of instances at a node to determine the split. The empirical results show that ensembles generated using this approach yield results that are competitive in accuracy and superior in computational cost to boosting and bagging.
Date: July 26, 2001
Creator: Kamath, C. & Cantu-Paz, E.
Object Type: Article
System: The UNT Digital Library
National Counterdrug Center (NCC) Simulation System Operational Requirements Document (ORD) Version 2 (open access)

National Counterdrug Center (NCC) Simulation System Operational Requirements Document (ORD) Version 2

This Operational Requirements Document (ORD) describes the capabilities that need to be incorporated in the NCC interactive simulation system being developed under the auspices of the NCC development program. The ORD addresses the necessary capabilities (i.e. what the system needs to be able to do); it defines the envelope of situations and circumstances that the NCC system must be able to represent and operate within. The NCC system will be developed in modules over a period of several years. This ORD, Version 2, supersedes the previous version. Future updates of this ORD are anticipated to be issued as needed to guide the development of later versions of the NCC system.
Date: January 26, 2001
Creator: Holter, Gregory M.
Object Type: Report
System: The UNT Digital Library
Data Catalog for Models Simulating Release of Contaminants from Hanford Site Waste Sources (open access)

Data Catalog for Models Simulating Release of Contaminants from Hanford Site Waste Sources

This report provides summaries of release models used in Hanford Site assessments published over the past 14 years (1987 to 2001). Mathematical formulations that commonly have been used in recent years (i.e., salt-cake, cement, soil-debris, reactor block, glass, and corrosion) are described, along with associated parameter definitions and their units. Tables in this report provide links to data sources needed to implement the models. These links enable users to quickly locate the specific release model information and data sources they need for applying the models to future to site assessments.
Date: September 26, 2001
Creator: Riley, Robert G. & Lopresti, Charles A.
Object Type: Report
System: The UNT Digital Library
Pure Phase Solubility Limits: LANL (open access)

Pure Phase Solubility Limits: LANL

The natural and engineered system at Yucca Mountain (YM) defines the site-specific conditions under which one must determine to what extent the engineered and the natural geochemical barriers will prevent the release of radioactive material from the repository. Most important mechanisms for retention or enhancement of radionuclide transport include precipitation or co-precipitation of radionuclide-bearing solid phases (solubility limits), complexation in solution, sorption onto surfaces, colloid formation, and diffusion. There may be many scenarios that could affect the near-field environment, creating chemical conditions more aggressive than the conditions presented by the unperturbed system (such as pH changes beyond the range of 6 to 9 or significant changes in the ionic strength of infiltrated waters). For an extended period of time, the near-field water composition may be quite different and more extreme in pH, ionic strength, and CO{sub 2} partial pressure (or carbonate concentration) than waters at some distance from the repository. Reducing conditions, high pH (up to 11), and low carbonate concentration may be present in the near-field after reaction of infiltrating groundwater with engineered barrier systems, such as cementitious materials. In the far-field, conditions are controlled by the rock-mass buffer providing a near-neutral, oxidizing, low-ionic-strength environment that controls radionuclide solubility …
Date: January 26, 2001
Creator: Stockman, C.
Object Type: Report
System: The UNT Digital Library
Characterization of the Radiation Shielding Properties of US andRussian EVA Suits (open access)

Characterization of the Radiation Shielding Properties of US andRussian EVA Suits

Reported herein are results from the Eril Research, Inc.(ERI) participationin the NASA Johnson Space Center sponsored studycharacterizing the radiation shielding properties of the two types ofspace suit that astronauts are wearing during the EVA on-orbit assemblyof the International Space Station (ISS). Measurements using passivedetectors were carried out to assess the shielding properties of the USEMU Suit and the Russian Orlan-M suit during irradiations of the suitsand a tissue equivalent phantom to monoenergetic proton and electronbeams at the Loma Linda University Medical Center (LLUMC). Duringirradiations of 6 MeV electrons and 60 MeV protons, absorbed dose as afunction of depth was measured using TLDs exposed behind swatches of thetwo suit materials and inside the two EVA helmets. Considerable reductionin electron dosewas measured behind all suit materials in exposures to 6MeV electrons. Slowing of the proton beam in the suit materials led to anincrease in dose measured in exposures to 60 MeV protons. During 232 MeVproton irradiations, measurements were made with TLDs and CR-39 PNTDs atfive organ locations inside a tissue equivalent phantom, exposed bothwith and without the two EVA suits. The EVA helmets produce a 13 to 27percent reduction in total dose and a 0 to 25 percent reduction in doseequivalent when …
Date: October 26, 2001
Creator: Benton, E. R.; Benton, E. V. & Frank, A. L.
Object Type: Report
System: The UNT Digital Library
Horizontal Drop of 21- PWR Waste Package (open access)

Horizontal Drop of 21- PWR Waste Package

The objective of this calculation is to determine the structural response of the waste package (WP) dropped horizontally from a specified height. The WP used for that purpose is the 21-Pressurized Water Reactor (PWR) WP. The scope of this document is limited to reporting the calculation results in terms of stress intensities. The information provided by the sketches (Attachment I) is that of the potential design of the type of WP considered in this calculation, and all obtained results are valid for that design only. This calculation is associated with the WP design and was performed by the Waste Package Design group in accordance with the ''Technical Work Plan for: Waste Package Design Description for LA'' (Ref. 16). AP-3.12Q, ''Calculations'' (Ref. 11) is used to perform the calculation and develop the document. The sketches attached to this calculation provide the potential dimensions and materials for the 21-PWR WP design.
Date: April 26, 2001
Creator: Scheider, A.K.
Object Type: Report
System: The UNT Digital Library
Low-Temperature, Anode-Supported High Power Density Solid Oxide Fuel Cells With Nanostructured Electrodes (open access)

Low-Temperature, Anode-Supported High Power Density Solid Oxide Fuel Cells With Nanostructured Electrodes

Anode-supported solid oxide fuel cells with Ni + yttria-stabilized zirconia (YSZ) anode, YSZ-samaria-doped ceria (SDC) bi-layer electrolyte and Sr-doped LaCoO{sub 3} (LSC) + SDC cathode were fabricated. Fuel used consisted of H{sub 2} diluted with He, N{sub 2}, H{sub 2}O or CO{sub 2}, mixtures of H{sub 2} and CO, and mixtures of CO and CO{sub 2}. Cell performance was measured at 800 C with above-mentioned fuel gas mixtures and air as oxidant. For a given concentration of the diluent, the cell performance was higher with He as the diluent than with N{sub 2} as the diluent. Mass transport through porous Ni-YSZ anode for H{sub 2}-H{sub 2}O, CO-CO{sub 2} binary systems and H{sub 2}-H{sub 2}O-diluent gas ternary systems was analyzed using multicomponent gas diffusion theory. At high concentrations of the diluent, the maximum achievable current density was limited by the anodic concentration polarization. From this measured limiting current density, the corresponding effective gas diffusivity was estimated. Highest effective diffusivity was estimated for fuel gas mixtures containing H{sub 2}-H{sub 2}O-He mixtures ({approx}0.34 cm{sup 2}/s), and the lowest for CO-CO{sub 2} mixtures ({approx}0.07 cm{sup 2}/s). The lowest performance was observed with CO-CO{sub 2} mixture as a fuel, which in part was attributed to …
Date: September 26, 2001
Creator: Virkar, Anil V.
Object Type: Report
System: The UNT Digital Library
Electron-cloud measurements and simulations for the APS (open access)

Electron-cloud measurements and simulations for the APS

We compare experimental results with simulations of the electron cloud effect induced by a positron beam at the APS synchrotron light source at ANL, where the electron cloud effect has been observed and measured with dedicated probes. We find good agreement between simulations and measurements for reasonable values of certain secondary electron yield (SEY) parameters, most of which were extracted from recent bench measurements at SLAC.
Date: June 26, 2001
Creator: Furman, M. A.; Pivi, M.; Harkay, K. C. & Rosenberg, R. A.
Object Type: Article
System: The UNT Digital Library
Development of an on-Line Coal Washability Analyzer (open access)

Development of an on-Line Coal Washability Analyzer

Washability analysis is the basis for nearly all coal preparation plant separations. Unfortunately, there are no on- line techniques for determining this most fundamental of all coal cleaning information. In light of recent successes at the University of Utah, it now appears possible to determine coal washability on-line through the use of x-ray computed tomography (CT) analysis. The successful development of such a device is critical to the establishment of process control and automated coal blending systems. In this regard, Virginia Tech, Terra Tek Inc., and U.S. coal producers have joined with the University of Utah and to undertake the development of an X-ray CT-based on- line coal washability analyzer with financial assistance from DOE. Each project participant brought special expertise to the project in order to create a new dimension in coal cleaning technology. The project involves development of appropriate software and extensive testing/evaluation of well-characterized coal samples from operating coal preparation plants. Data collected to date suggest that this new technology is capable of serving as a universal analyzer that can not only provide washability analysis, but also particle size distribution analysis, ash analysis, and perhaps pyritic sulfur analysis.
Date: June 26, 2001
Creator: Miller, J. D.; Lin, C. L.; Luttrell, G. H.; Adel, G. T. & Marin, Barbara
Object Type: Report
System: The UNT Digital Library
New simulation results for the electron-cloud effect at the PEP-II positron ring (open access)

New simulation results for the electron-cloud effect at the PEP-II positron ring

We present simulation results for the emittance blowup due to the head-tail effect induced by the electron-cloud effect (ECE) in the low-energy ring (LER) at the PEP-II B factory at SLAC.
Date: June 26, 2001
Creator: Cai, Y.; Heifets, S.; Seeman, J.; Furman, M. & Pivi, M.
Object Type: Article
System: The UNT Digital Library
Microstructural and conductivity comparison of Ag films grown on amorphous TiO2 and polycrystalline ZnO (open access)

Microstructural and conductivity comparison of Ag films grown on amorphous TiO2 and polycrystalline ZnO

8 nm thick Ag films were sputter deposited onto amorphous TiO{sub 2} underlayers 25 nm thick, and also amorphous TiO{sub 2} (25 nm)/ZnO (5 nm) multiunderlayers. The substrates were back-etched Si with a 50 nm thick LPCVD Si{sub 3}N{sub 4} electron transparent membrane. The ZnO, sputtered onto amorphous TiO{sub 2}, formed a continuous layer with a grain size of 5 nm in diameter, on the order of the film thickness. There are several microstructural differences in the Ag dependent on the underlayers, revealed by TEM. First a strong {l_brace}0001{r_brace} ZnO to {l_brace}111{r_brace} Ag fibre-texture relationship exists. On TiO{sub 2} the Ag microstructure shows many abnormal grains whose average diameter is about 60-80 nm, whereas the films on ZnO show few abnormal grains. The background matrix of normal grains on the TiO{sub 2} is roughly 15 nm, while the normal grain size on the ZnO is about 25 nm. Electron diffraction patterns show that the film on ZnO has a strong {l_brace}111{r_brace} orientation, and dark field images with this diffraction condition have a grain size of about 30 nm. In a region near the center of the TEM grid where there is the greatest local heating during deposition, Ag films grown …
Date: March 26, 2001
Creator: Dannenberg, Rand; Stach, Eric; Glenn, Darin; Sieck, Peter & Hukari, Kyle
Object Type: Report
System: The UNT Digital Library
Sensor guided control and navigation with intelligent machines. Final technical report (open access)

Sensor guided control and navigation with intelligent machines. Final technical report

This item constitutes the final report on ''Visionics: An integrated approach to analysis and design of intelligent machines.'' The report discusses dynamical systems approach to problems in robust control of possibly time-varying linear systems, problems in vision and visually guided control, and, finally, applications of these control techniques to intelligent navigation with a mobile platform. Robust design of a controller for a time-varying system essentially deals with the problem of synthesizing a controller that can adapt to sudden changes in the parameters of the plant and can maintain stability. The approach presented is to design a compensator that simultaneously stabilizes each and every possible mode of the plant as the parameters undergo sudden and unexpected changes. Such changes can in fact be detected by a visual sensor and, hence, visually guided control problems are studied as a natural consequence. The problem here is to detect parameters of the plant and maintain st ability in the closed loop using a ccd camera as a sensor. The main result discussed in the report is the role of perspective systems theory that was developed in order to analyze such a detection and control problem. The robust control algorithms and the visually guided control …
Date: March 26, 2001
Creator: Ghosh, Bijoy K.
Object Type: Report
System: The UNT Digital Library
A measurement of the branching ratio of K+-- ->pi+--mu+mu- decays in the Hyper CP experiment (open access)

A measurement of the branching ratio of K+-- ->pi+--mu+mu- decays in the Hyper CP experiment

Large samples of hyperon and kaon decays were collected with the Hyper CP spectrometer during two fixed-target runs at Fermilab. Based on an analysis of 110 million K pm decays from the 1997 data sample we present a branching ratio for K pm right arrow pi pm mu+ mu-. This is the first observation of K- right arrow pi- mu+ mu- decay.
Date: November 26, 2001
Creator: Zyla, Piotr & Collaborators, other HyperCP
Object Type: Article
System: The UNT Digital Library
Edge Turbulence Imaging in the Alcator C-Mod Tokamak (open access)

Edge Turbulence Imaging in the Alcator C-Mod Tokamak

The 2-D radial vs. poloidal structure of edge turbulence in the Alcator C-Mod tokamak [I.H. Hutchinson, R. Boivin, P.T. Bonoli et al., Nuclear Fusion 41(2001) 1391] was measured using fast cameras and compared with 3-D numerical simulations of edge plasma turbulence. The main diagnostic is Gas Puff Imaging (GPI), in which the visible D(subscript alpha) emission from a localized D(subscript 2) gas puff is viewed along a local magnetic field line. The observed D(subscript alpha) fluctuations have a typical radial and poloidal scale of approximately 1 cm, and often have strong local maxima (''blobs'') in the scrape-off layer. The motion of this 2-D structure motion has also been measured using an ultra-fast framing camera with 12 frames taken at 250,000 frames/sec. Numerical simulations produce turbulent structures with roughly similar spatial and temporal scales and transport levels as that observed in the experiment; however, some differences are also noted, perhaps requiring diagnostic improvement and/or additional physics in the numerical model.
Date: November 26, 2001
Creator: Zweben, S. J.; Stotler, D. P.; Terry, J. L.; LaBombard, B.; Greenwald, M.; Muterspaugh, M. et al.
Object Type: Report
System: The UNT Digital Library
The incorporation of GIS in radiological transportation accident consequence assessments. (open access)

The incorporation of GIS in radiological transportation accident consequence assessments.

Potential impacts of transportation accidents must be addressed in documents prepared under the National Environmental Protection Act (NEPA) as amended or in other environmental-related documents when the transportation of radioactive materials is considered. Estimating the potential human health consequences from the release and dispersion of radioactive materials following such an accident involves a number of interrelated computational models and a variety of input parameters. The RISKIND radiological transportation risk computer program [1] was developed to provide these types of estimates for local scenarios. However, it is often difficult to gain a full understanding of the initial problem and consequences by looking solely at numerical input and tables of results. To permit better-informed decisions, visualization of the site-specific geographic area and the potential spread of contamination can provide greater understanding. Thus, a geographic information system (GIS) component has been integrated with RISKIND to provide visualization capabilities as well as site-specific and computational benefits.
Date: June 26, 2001
Creator: Biwer, B. M.; LePoire, D. J.; Kuiper, J. A. & Chen, S. Y.
Object Type: Article
System: The UNT Digital Library
Application of Resin Transfer Molding to the Manufacture of Wind Turbine Blade Substructures. Final Report (open access)

Application of Resin Transfer Molding to the Manufacture of Wind Turbine Blade Substructures. Final Report

The U.S. has generally lacked the capability for an iterative process of detailed structural design, manufacturing, and testing at the full blade level to achieve specific structural performance, cost, and weight targets. This project examined the effects that different composites processing methods had on the performance of representative blade substructures. In addition, the results of the testing of these substructures was used to validate NuMAD, the design tool developed at Sandia National Laboratories.
Date: July 26, 2001
Creator: Hedley, C. W.; Ritter, W. J. & Ashwill, T.
Object Type: Report
System: The UNT Digital Library
Low Income Consumer Utility Issues: A National Perspective (open access)

Low Income Consumer Utility Issues: A National Perspective

This report has been prepared to provide low-income advocates and other stakeholders information on the energy burden faced by low-income customers and programs designed to alleviate that burden in various states. The report describes programs designed to lower payments, manage arrearages, weatherize and provide other energy efficiency measures, educate consumers, increase outreach to the target It discusses the costs and benefits of the population, and evaluate the programs. various options--to the degree this information is available--and describes attempts to quantify benefits that have heretofore not been quantified. The purpose of this report is to enable the low-income advocates and others to assess the options and design program most suitable for the citizens of their states or jurisdictions. It is not the authors' intent to recommend a particular course of action but, based on our broad experience in the field, to provide the information necessary for others to do so. We would be happy to answer any questions or provide further documentation on any of the material presented herein. The original edition of this report was prepared for the Utah Committee on Consumer Services, pursuant to a contract with the National Consumer Law Center (NCLC), to provide information to the Utah …
Date: March 26, 2001
Creator: Eisenberg, J
Object Type: Report
System: The UNT Digital Library
2001 Gordon Research Conference on Applied and Environmental Microbiology. Final progress report [agenda and attendee list] (open access)

2001 Gordon Research Conference on Applied and Environmental Microbiology. Final progress report [agenda and attendee list]

The Gordon Research Conference on Applied and Environmental Microbiology was held at Connecticut College, New London, Connecticut, July 22-27, 2001. The conference was attended by 121 participants. The attendees represented the spectrum of endeavor in this field, coming from academia, industry, and government laboratories, and included US and foreign scientists, senior researchers, young investigators, and students. Emphasis was placed on current unpublished research and discussion of the future target areas in this field. There was a conscious effort to stimulate discussion about the key issues in the field today. Session topics included the following: Environmental and applied genomics, Cell-to-cell signaling and multicellular behavior, Emerging technologies and methods, Novel metabolisms and ecosystems, Directed evolution of enzymes and pathways, Symbiotic and trophic relationships, Synthesis and application of novel biopolymers, and Microbes at the oxic-anoxic interface. There was also a special lecture titled ''Under the umbrella of the big tree: microbial biology into the 21st century.''
Date: July 26, 2001
Creator: Drake, Harold
Object Type: Report
System: The UNT Digital Library
Dual Manifold System for Arraying Biomolecules (open access)

Dual Manifold System for Arraying Biomolecules

The objective of this CRADA is to establish a new approach to fluid transfer and array construction. This new approach will involve a high-speed, multiplexed fluid distribution valve and ink jet valves. It will enable the parallel handling of multiple reagents for a system that will have multiple applications in addition to the high-speed construction of microarrays. The primary tasks involve proof of principle experiments aimed at establishing key components of the technology and evaluating various optional configurations. The basic platform for evaluating the technology will be set-up by the Contractor at Oak Ridge National Laboratory (ORNL) and will employ custom valving prepared by Rheodyne. The test platform will consist of a motion controller, 3-axes of motion, software, and pneumatic control; and will be used to evaluate the hybrid valve.
Date: April 26, 2001
Creator: Doktycz, M.J.
Object Type: Report
System: The UNT Digital Library
The industrial ecology of steel (open access)

The industrial ecology of steel

This study performs an integrated assessment of new technology adoption in the steel industry. New coke, iron, and steel production technologies are discussed, and their economic and environmental characteristics are compared. Based upon detailed plant level data on cost and physical input-output relations by process, this study develops a simple mathematical optimization model of steel process choice. This model is then expanded to a life cycle context, accounting for environmental emissions generated during the production and transportation of energy and material inputs into steelmaking. This life-cycle optimization model provides a basis for evaluating the environmental impacts of existing and new iron and steel technologies. Five different plant configurations are examined, from conventional integrated steel production to completely scrap-based operations. Two cost criteria are used to evaluate technology choice: private and social cost, with the latter including the environmental damages associated with emissions. While scrap-based technologies clearly generate lower emissions in mass terms, their emissions of sulfur dioxide and nitrogen oxides are significantly higher. Using conventional damage cost estimates reported in the literature suggests that the social costs associated with scrap-based steel production are slightly higher than with integrated steel production. This suggests that adopting a life-cycle viewpoint can substantially affect …
Date: March 26, 2001
Creator: Considine, Timothy J.; Jablonowski, Christopher; Considine, Donita M. M. & Rao, Prasad G.
Object Type: Report
System: The UNT Digital Library