Certification Testing and Demonstration of Insulated Pressure Vessels for Vehicular Hydrogen Storage (open access)

Certification Testing and Demonstration of Insulated Pressure Vessels for Vehicular Hydrogen Storage

Insulated pressure vessels are cryogenic-capable pressure vessels that can be fueled with liquid hydrogen or ambient-temperature compressed hydrogen. This flexibility results in multiple advantages with respect to compressed hydrogen tanks or low-pressure liquid hydrogen tanks. Our work is directed at verifying that commercially available aluminum-lined, fiber-wrapped pressure vessels can be safely used to store liquid hydrogen. A series of tests have been conducted, and the results indicate that no significant vessel damage has resulted from cryogenic operation. Future activities 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 certification of insulated pressure vessels.
Date: May 22, 2002
Creator: Aceves, S. M.; Martinez-Frias, J. & Espinosa-Loza, F.
System: The UNT Digital Library
Impulsive Stimulated Light Scattering at High Pressure - Precise Determination of Elastic Constants of Opaque Materials (open access)

Impulsive Stimulated Light Scattering at High Pressure - Precise Determination of Elastic Constants of Opaque Materials

Impulsive stimulated light scattering has been used to measure interfacial wave propagation speeds and elastic constants under conditions of high pressure. Data obtained from single-crystal Ge and Fe, and from polycrystalline Ta is presented. The method is complementary to other techniques for obtaining this type of information. There appears no fundamental reason why it cannot be extended to the 1 Mbar regime.
Date: August 22, 2002
Creator: Crowhurst, J C; Zaug, J M; Abramson, E H; Brown, J M & Ahre, D W
System: The UNT Digital Library
Initial experiments of RF gas plasma source for heavy ionfusion (open access)

Initial experiments of RF gas plasma source for heavy ionfusion

The Source Injector Program for the US Heavy Ion Fusion Virtual National Laboratory is currently exploring the feasibility of using RF gas plasma sources for a HIF driver. This source technology is presently the leading candidate for the multiple aperture concept, in which bright millimeter size beamlets are extracted and accelerated electrostatically up to 1 MeV before the beamlets are allowed to merge and form 1 A beams. Initial experiments have successfully demonstrated simultaneously high current density, {approx} 100 mA/cm{sup 2} and fast turn on, {approx} 1 {micro}s. These experiments were also used to explore operating ranges for pressure and RF power. Results from these experiments are presented as well as progress and plans for the next set of experiments for these sources.
Date: May 22, 2002
Creator: Ahle, L.; Hall, R.; Molvik, A. W.; Chacon-Golcher, E.; Kwan, J. W.; Leung, K. N. et al.
System: The UNT Digital Library
Corrosion of Titanium Matrix Composites (open access)

Corrosion of Titanium Matrix Composites

The corrosion behavior of unalloyed Ti and titanium matrix composites containing up to 20 vol% of TiC or TiB{sub 2} was determined in deaerated 2 wt% HCl at 50, 70, and 90 degrees C. Corrosion rates were calculated from corrosion currents determined by extrapolation of the tafel slopes. All curves exhibited active-passive behavior but no transpassive region. Corrosion rates for Ti + TiC composites were similar to those for unalloyed Ti except at 90 degrees C where the composites were slightly higher. Corrosion rates for Ti + TiB{sub 2} composites were generally higher than those for unalloyed Ti and increased with higher concentrations of TiB{sub 2}. XRD and SEM-EDS analyses showed that the TiC reinforcement did not react with the Ti matrix during fabrication while the TiB{sub 2} reacted to form a TiB phase.
Date: September 22, 2002
Creator: Covino, B. S., Jr. & Alman, D. E.
System: The UNT Digital Library
Current status of dense ceramic membranes for hydrogen separation. (open access)

Current status of dense ceramic membranes for hydrogen separation.

We have developed cermet membranes that nongalvanically separate hydrogen from gas mixtures. The highest measured hydrogen flux was 16.2 cm{sup 3} (STP)/min-cm{sup 2} for an ANL-3a membrane at 900 C. For ANL-3 membranes with thickness of 0.04-0.5 mm, permeation rate is limited by the bulk diffusion of hydrogen through the metal phase. The effect of hydrogen partial pressure on permeation rate confirmed this conclusion and suggested that higher permeation rates may be obtained by decreasing the membrane thickness. Permeation rate in a syngas atmosphere for times up to 190 h showed no degradation in performance, which indicates that ANL-3 may be suitable for long-term, practical hydrogen separation.
Date: February 22, 2002
Creator: Balachandran, U.; Lee, T. H.; Wang, S.; Zhang, G. & Dorris, S. E.
System: The UNT Digital Library
Experiences with remote electron microscopy (open access)

Experiences with remote electron microscopy

With the advent of a rapidly proliferating international computer network, it became feasible to consider remote operation of instrumentation normally operated locally. For modern electron microscopes, the growing automation and computer control of many instrumental operations facilitated the task of providing remote operation. In order to provide use of NCEM TEMs by distant users, a project was instituted in 1995 to place a unique instrument, a Kratos EM-1500 operating at 1.5MeV, on-line for remote use. In 1996, the Materials Microcharacterization Collaboratory (MMC) was created as a pilot project within the US Department of Energy's DOE2000 program to establish national collaboratories to provide access via the Internet to unique or expensive DOE research facilities as well as to expertise for remote collaboration, experimentation, production, software development, modeling, and measurement. A major LBNL contribution to the MMC was construction of DeepView, a microscope-independent computer-control system that could be ported to other MMC members to provide a common graphical user-interface (GUI) for control of any MMC instrument over the wide area network.
Date: February 22, 2002
Creator: O'Keefe, Michael A. & Parvin, Bahram
System: The UNT Digital Library
Status of the VIM Monte Carlo neutron/photon transport code. (open access)

Status of the VIM Monte Carlo neutron/photon transport code.

Recent work on the VIM Monte Carlo code has aimed at advanced data libraries, ease of use, availability to users outside of Argonne, and fission source convergence algorithms in eigenvalue calculations. VIM is one of three US Monte Carlo codes in the USDOE Nuclear Criticality Safety Program, and is available through RSICC and the NEA Data Bank.
Date: January 22, 2002
Creator: Blomquist, R.N.
System: The UNT Digital Library
Thermal Uniformity of Liquid Helium in Electron Bubble Chamber. (open access)

Thermal Uniformity of Liquid Helium in Electron Bubble Chamber.

A CRYOGENIC RESEARCH APPARATUS TO MEASURE THE MOVEMENT OF ELECTRONS UNDER A HIGH ELECTRIC FIELD IN A LIQUID HELIUM BATH WAS DESIGNED AND BUILT AT THE BROOKHAVEN NATIONAL LABORATORY AND THE NEVIS LABORATORY OF COLUMBIA UNIVERSITY. THE LIQUID HELIUM CHAMBER IS A DOUBLE WALLED CYLINDRICAL CONTAINER EQUIPPED WITH 5 OPTICS WINDOWS AND 10 HIGH VOLTAGE CABLES. TO SHIELD THE LIQUID HELIUM CHAMBER AGAINST THE EXTERNAL HEAT LOADS AND TO PROVIDE THE THERMAL UNIFORMITY IN THE LIQUID HELIUM CHAMBER, THE DOUBLE WALLED JACKET WAS COOLED BY A PUMPED HELIUM BATH. THE HELIUM CHAMBER WAS BUILT INTO A COMMERICAL LN2 / LHE CRYOSTAT. THIS PAPER PRESENTS THE DESIGN AND THE NUMERICAL SIMULATION ANALYSIS ON THERMAL UNIFORMITY OF THE ELECTRON BUBBLE CHAMBER.
Date: July 22, 2002
Creator: Wang, L. & Jia, L.
System: The UNT Digital Library
Jet production at CDF (open access)

Jet production at CDF

In this talk I present the results from the measurement of the inclusive jet cross section and strong coupling constant based on the CDF Run 1B data, and discuss prospects for Run 2.
Date: April 22, 2002
Creator: Mesropian, Christina
System: The UNT Digital Library
A High-Speed Four-Channel Infrared Pryometer. (open access)

A High-Speed Four-Channel Infrared Pryometer.

None
Date: August 22, 2002
Creator: Boboridis, Konstatinos & Obst, Andrew W.
System: The UNT Digital Library
METALLIZATION OF CERAMIC VACUUM CHAMBERS FOR SNS RING INJECTION KICKER MAGNETS. (open access)

METALLIZATION OF CERAMIC VACUUM CHAMBERS FOR SNS RING INJECTION KICKER MAGNETS.

Ceramic chambers will be used in the pulsed kicker magnets for the injection of H{sup -} into the US Spallation Neutron Source (SNS) accumulator ring. There are two reasons for using ceramic chambers in kickers: (1) to avoid shielding of a fast-changing external magnetic field by metallic chamber walls; and (2) to reduce heating due to eddy currents. The inner surfaces of the ceramic chambers will be coated with a conductive layer, possibly titanium (Ti) or copper with a titanium nitride (TiN) overlayer, to reduce the beam coupling impedance and provide passage for beam image current. This paper describes the development of sputtering method for the 0.83m long 16cm inner diameter ceramic chambers. Coatings of Ti, Cu and TiN with thicknesses up to 10 {micro}m were produced by means of DC magnetron sputtering. The difficulty of coating insulators was overcome with the introduction of an anode screen. Films with good adhesion, uniform longitudinal thickness, and conductivity were produced.
Date: April 22, 2002
Creator: He, P.; Hseuh, H. C. & Todd, R. J.
System: The UNT Digital Library
RELAP5 / MOD3.2 analysis of INSC standard problem INSCSP - R7 : void fraction distribution over RBMK fuel channel height for experiments performed in the ENTEK BM test facility. (open access)

RELAP5 / MOD3.2 analysis of INSC standard problem INSCSP - R7 : void fraction distribution over RBMK fuel channel height for experiments performed in the ENTEK BM test facility.

The RELAP5/MOD3.2 computer program has been used to analyze a series of tests investigating void fraction distribution over height in RBMK fuel channels performed in Facility BM at the ENTEK. This is RBMK Standard Problem 7 in Joint Project 6, which is the investigation of Computer Code Validation for Transient Analysis of RBMK and VVER Reactors, between the United States and Russian Minatom International Nuclear Safety Centers. The experiment facility and data, RELAP5 nodalization, and results are shown for all tests. Agreement between RELAP5 and the experiment data is reasonable.
Date: August 22, 2002
Creator: Garner, P. L.
System: The UNT Digital Library
Epimorphin mediates mammary luminal morphogenesis through control of C/EBPbeta (open access)

Epimorphin mediates mammary luminal morphogenesis through control of C/EBPbeta

We have previously shown that epimorphin, a protein expressed on the surface of myoepithelial and fibroblast cells of the mammary gland, acts as a multifunctional morphogen of mammary epithelial cells. Here, we present the molecular mechanism by which epimorphin mediates luminal morphogenesis. Treatment of cells with epimorphin to induce lumen formation greatly increases the overall expression of transcription factor CCAAT/enhancer binding protein beta (C/EBPbeta) and alters the relative expression of its two principal isoforms, LIP and LAP. These alterations were shown to be essential for the morphogenetic activities, as constitutive expression of LIP was sufficient to produce lumen formation, while constitutive expression of LAP blocked epimorphin-mediated luminal morphogenesis. Furthermore, in a transgenic mouse model in which epimorphin expression was expressed in an apolar fashion on the surface of mammary epithelial cells, we found increased expression of C/EBPbeta, increased relative expression of LIP to LAP, and enlarged ductal lumina. Together, our studies demonstrate a role for epimorphin in luminal morphogenesis through control of C/EBPbeta expression.
Date: March 22, 2002
Creator: Hirai, Yohei; Radisky, Derek; Boudreau, Rosanne; Simian, Marina; Stevens, Mary E.; Oka, Yumiko et al.
System: The UNT Digital Library
Phosphate-stabilized Lithium intercalation compounds (open access)

Phosphate-stabilized Lithium intercalation compounds

Four manganese and iron phosphates with alluaudite or fillowite structures have been prepared by solid state reactions: Na2FeMn2(PO4)3, LiNaFeMn2(PO4)3, NaFe3(PO4)3, and Na2Mn3(PO4)3. LixNa2-xFeMn2(PO4)3 with x close to 2 was prepared from Na2FeMn2(PO4)3 by molten salt ion exchange. These materials are similar in stoichiometry to the phospho-olivines LiFe(Mn)PO4, but have a more complex structure that can accommodate mixed transition metal oxidation states. They are of interest as candidates for lithium battery cathodes because of their somewhat higher electronic conductivity, high intercalant ion mobility, and ease of preparation. Their performance as intercalation electrodes in non-aqueous lithium cells was, however, poor.
Date: July 22, 2002
Creator: Richardson, Thomas J.
System: The UNT Digital Library
Microfabrication of freestanding metal structures released from graphite substrates. (open access)

Microfabrication of freestanding metal structures released from graphite substrates.

A sacrificial layer is usually used to release electroformed microstructures. Because of the chemistry applied to the sacrificial layer, only a limited number of metals can be used for electroforming. A novel method to fabricate freestanding electroformed copper structures is presented. A graphite substrate allows the release of the metal part, by abrasive removal of the graphite after electroforming. Results on fabrication of high-aspect-ratio freestanding copper grids are presented; these can be used as x-ray collimator in medical imaging to reduce scattered radiation. This process has potential application to the fabrication of injection molds and microparts on pick-and-place carriers for microelectromechanical systems (MEMS).
Date: February 22, 2002
Creator: Makarova, O. V.; Tang, C.-M.; Mancini, D. C.; Moldovan, N.; Divan, R.; Ryding, D. G. et al.
System: The UNT Digital Library
Bunch shape measurement of CW heavy-ion beam. (open access)

Bunch shape measurement of CW heavy-ion beam.

An accurate bunch shape measurement is one of the most important tasks during the fine tuning of multicavity accelerators. A device for the measurement of bunch time structure of cw heavy-ion beams with time resolution {approx}20 picoseconds was developed, constructed and commissioned at ATLAS which is a 50 MV superconducting heavy-ion linac. The Bunch Shape Monitor (BSM) is based on the analysis of secondary electrons produced by a primary beam hitting a tungsten wire to which a potential of -10 kV is applied. In a BSM the longitudinal distribution of charge of the primary beam is coherently transformed into a spatial distribution of low energy secondary electrons through transverse rf modulation. The distribution of secondary electrons is detected by a chevron MCP coupled to a phosphor screen. The signal image on the screen is measured by use of a CCD camera connected to a PC. This BSM analyzes cw beams rather than pulsed beams studied by a previous device [1]. Design features of the BSM and the beam measurement results are reported.
Date: August 22, 2002
Creator: Vinogradov, N. Y.; Billquist, P.; Ostroumov, P. N.; Pardo, R. C.; Portillo, M.; Sharamentov, S. I. et al.
System: The UNT Digital Library
Confidence limits and their errors (open access)

Confidence limits and their errors

Confidence limits are common place in physics analysis. Great care must be taken in their calculation and use especially in cases of limited statistics. We introduce the concept of statistical errors of confidence limits and argue that not only should limits be calculated but also their errors in order to represent the results of the analysis to the fullest. We show that comparison of two different limits from two different experiments becomes easier when their errors are also quoted. Use of errors of confidence limits will lead to abatement of the debate on which method is best suited to calculate confidence limits.
Date: March 22, 2002
Creator: Raja, Rajendran
System: The UNT Digital Library
Uranium Co-Precipitation with Iron Oxide Minerals (open access)

Uranium Co-Precipitation with Iron Oxide Minerals

In oxidizing environments, the toxic and radioactive element uranium is most soluble and mobile in the hexavalent oxidation state. These processes also affect the biological availability of U(VI) species toward reduction and precipitation as the less soluble U(IV) species by metal-reducing bacteria. The results provide compelling evidence of U incorporation within the hematite structure.
Date: May 22, 2002
Creator: Duff, M.C.
System: The UNT Digital Library
Supporting collaborative computing and interaction (open access)

Supporting collaborative computing and interaction

To enable collaboration on the daily tasks involved in scientific research, collaborative frameworks should provide lightweight and ubiquitous components that support a wide variety of interaction modes. We envision a collaborative environment as one that provides a persistent space within which participants can locate each other, exchange synchronous and asynchronous messages, share documents and applications, share workflow, and hold videoconferences. We are developing the Pervasive Collaborative Computing Environment (PCCE) as such an environment. The PCCE will provide integrated tools to support shared computing and task control and monitoring. This paper describes the PCCE and the rationale for its design.
Date: May 22, 2002
Creator: Agarwal, Deborah; McParland, Charles & Perry, Marcia
System: The UNT Digital Library
Mathematical comparison of three tritium system effluent HTO cleanup systems (open access)

Mathematical comparison of three tritium system effluent HTO cleanup systems

It is important that air emissions from tritium systems be kept as low as reasonably achievable. Thus, over the years a number of gas detritiation systems have been developed. Recently there has been interest in lower-cost, simpler systems which do not convert HT to the much more hazardous HTO form. Examples of such systems are (1) a bubbler/dehumidifier, (2) a bubbler/collector, and (3) an adsorber/collector. A computer model of each configuration was written and run. Each system's performance, including tritium buildup in liquid water, and tritium exhausted to the environment, are presented and compared.
Date: March 22, 2002
Creator: Willms, R.Scott; Gentile, Charles; Rule, Keith; Than, Chit & Williams, Philip
System: The UNT Digital Library
High-temperature corrosion in power-generating systems. (open access)

High-temperature corrosion in power-generating systems.

Several technologies are being developed to convert coal into clean fuel for use in power generation. From the standpoint of component materials in these technologies, the environments created by coal conversion and their interactions with materials are of interest. Coal is a complex and relatively dirty fuel that contains varying amounts of sulfur and a substantial fraction of noncombustible mineral constituents, commonly called ash. Corrosion of metallic and ceramic structural materials is a potential problem at elevated temperatures in the presence of complex gas environments and coal-derived solid/liquid deposits. This paper discusses the coal-fired systems currently under development, identifies several modes of corrosion degradation that occur in many of these systems, and suggests possible mechanisms of metal wastage. Available data on the performance of materials in some of the environments are highlighted, and the research needed to improve the corrosion resistance of various materials is presented.
Date: May 22, 2002
Creator: Natesan, K.
System: The UNT Digital Library
Maximizing Return From Sound Analysis and Design Practices (open access)

Maximizing Return From Sound Analysis and Design Practices

With today's tightening budgets computer applications must provide ''true'' long-term benefit to the company. Businesses are spending large portions of their budgets ''Re-Engineering'' old systems to take advantage of ''new'' technology. But what they are really getting is simply a new interface implementing the same incomplete or poor defined requirements as before. ''True'' benefit can only be gained if sound analysis and design practices are used. WHAT data and processes are required of a system is not the same as HOW the system will be implemented within a company. It is the System Analyst's responsibility to understand the difference between these two concepts. The paper discusses some simple techniques to be used during the Analysis and Design phases of projects, as well as the information gathered and recorded in each phase and how it is transformed between these phases. The paper also covers production application generated using Oracle Designer. Applying these techniques to ''real world'' problems, the applications will meet the needs for today's business and adapt easily to ever-changing business environments.
Date: April 22, 2002
Creator: Bramlette, J.D.
System: The UNT Digital Library
Cryogenics in Bepcii Upgrade. (open access)

Cryogenics in Bepcii Upgrade.

THIS PAPER PRESENTS A CRYOGENIC DESIGN FOR UPGRADING THE BEIJING ELECTRON POSITRON COLLIDER AT THE INSTITUTE OF HIGH ENERGY PHYSICS IN BEIJING. THE UPGRADE INVOLVES 3 NEW SUPERCONDUCTING FACILITIES, THE INTERACTION REGION QUADRUPOLE MAGNETS, THE DETECTOR SOLENOID MAGNETS AND THE SRF CAVITIES. FOR COOLING OF THESE DEVICES, A NEW CRYPLANT WITH A TOTAL CAPACITY OF 1.0KW AT 4.5K IS TO BE BUILT AT IHEP. AN INTEGRATED CRYOGENIC DESIGN TO FIT THE BEPCII CRYOGENIC LOADS WITH HIGH EFFICIENCY IS CARRIEDOUT USING COMPUTATIONAL PROCESS ANALYSIS SOFTWARE WITH THE EMPHASES ON ECONOMICS AND SAFETY IN BOTH CONSTRUCTION AND OPERATION OF THE PLANT. THIS PAPER DESCRIBES THE CRYOGENIC CHARACTERISTICS OF EACH SUPERCONDUCTING DEVICE, THEIR COOLING SCHEMES AND THE OVERALL CRYOPLANT.
Date: July 22, 2002
Creator: Jia, L.; Wang, L. & Li, S.
System: The UNT Digital Library
Report of the First Community Consultation on the Responsible Collection and Use of Samples for Genetic Research, September 25-26, 2000 (open access)

Report of the First Community Consultation on the Responsible Collection and Use of Samples for Genetic Research, September 25-26, 2000

The First Community Consultation on the Responsible Collection and Use of Samples for Genetic Research was held in Bethesda, Maryland, on September 25-26, 2000. The consultation was convened by the National Institute of General Medical Sciences (NIGMS) of the National Institutes of Health (NIH). Approximately 120 individuals participated in the consultation, half from a broad range of communities and populations, and half from government. The participants shared their views and concerns about population- and community-based genetic research, expanding the focus of the meeting from the collection and use of blood or other tissue samples for genetic research to broader issues and concerns about the conduct of genetic research in general with populations and communities.
Date: May 22, 2002
Creator: Greenberg, Judith H.
System: The UNT Digital Library