States

Direct Measurement of A{sub c} using Inclusive Charm Tagging at the SLD Detector (open access)

Direct Measurement of A{sub c} using Inclusive Charm Tagging at the SLD Detector

We report a new measurement of A{sub c} using data obtained by SLD in 1993-98. This measurement uses a vertex tag technique, where the selection of a c hemisphere is based on the reconstructed mass of the charm hadron decay vertex. The method uses the 3D vertexing capabilities of SLD's CCD vertex detector and the small and stable SLC beams to obtain a high c-event tagging efficiency and purity of 28% and 82%, respectively. Charged kaons identified by the CRID detector and the charge of the reconstructed vertex provide an efficient quark-antiquark tag, with the analyzing power calibrated from the data. We obtain a preliminary result of A{sub c} = 0.603 {+-} 0.028 {+-} 0.023.
Date: July 14, 1999
Creator: Abe, K
Object Type: Report
System: The UNT Digital Library
Distinguishing Indirect Signatures Arising From New Physics at the NLC (open access)

Distinguishing Indirect Signatures Arising From New Physics at the NLC

Many sources of new physics can lead to shifts in the Standard Model predictions for cross sections and asymmetries at the NLC below their direct production thresholds. In this talk we discuss some of the tools that are useful for distinguishing amongst these new physics scenarios. R-parity violation and extensions of the Standard Model gauge structure are two typical non-minimal realizations of supersymmetry which provide us with an important test case to examine.
Date: July 14, 1999
Creator: Rizzo, Thomas G.
Object Type: Report
System: The UNT Digital Library
Beam-Cavity Interaction Circuit at W-Band (open access)

Beam-Cavity Interaction Circuit at W-Band

We describe the design, fabrication and bench-study of a mm-wave cavity employed as a relativistic klystron output structure. The OFE copper cavity was prepared by electro-discharge machining and diffusion bonding, cleaned, and tuned to 91.4 GHz. Measured cavity characteristics are presented and compared with theory, including quality factor, Q, coupling parameter {beta}, scattering matrix S{sub 11}, and axial electric field profile E{sub z}. This work provides the basis for understanding of the cavity as a transfer structure.
Date: July 14, 1999
Creator: Hill, Marc E
Object Type: Report
System: The UNT Digital Library
Direct Measurement of A{sub b} using Charged Kaons at the SLD Detector (open access)

Direct Measurement of A{sub b} using Charged Kaons at the SLD Detector

We report a new measurement of A{sub b} using data obtained by SLD in 1997-98. This measurement uses a vertex tag technique, where the selection of a b hemisphere is based on the reconstructed mass of the bottom hadron decay vertex. The method uses the 3D vertexing capabilities of SLD's CCD vertex detector and the small and stable SLC beams to obtain a high b-event tagging efficiency and purity of 78% and 97%, respectively. Charged kaons identified by the CRID detector provide an efficient quark-antiquark tag, with the analyzing power calibrated from the data. We obtain a preliminary result of A{sub b} = 0.997 {+-} 0.044 {+-} 0.067.
Date: July 14, 1999
Creator: Wright, Thomas R
Object Type: Report
System: The UNT Digital Library
Increased oil production and reserves utilizing secondary/tertiary recovery techniques on small reservoirs in the Paradox basin, Utah. Technical progress report, April 1, 1995--June 30, 1995 (open access)

Increased oil production and reserves utilizing secondary/tertiary recovery techniques on small reservoirs in the Paradox basin, Utah. Technical progress report, April 1, 1995--June 30, 1995

The primary objective of this project is to enhance domestic petroleum production by demonstration and technology transfer of an advanced oil recovery technology in the Paradox basin, southeastern Utah. If this project can demonstrate technical and economic feasibility, the technique can be applied to approximately 100 additional small fields in the Paradox basin alone, and result in increased recovery of 150 to 200 million barrels of oil. This project is designed to characterize five shallow-shelf carbonate reservoirs in the Pennsylvanian (Desmoinesian) Paradox Formation and choose the best candidate for a pilot demonstration project for either a waterflood or carbon dioxide-flood project. The field demonstration, monitoring of field performance, and associated validation activities will take place in the Paradox basin within the Navajo Nation. The results of this project will be transferred to industry and other researchers through a petroleum extension service, creation of digital databases for distribution, technical workshops and seminars, field trips, technical presentations at national and regional professional meetings, and publication in newsletters and various technical or trade journals.
Date: July 14, 1995
Creator: Allison, M. L.
Object Type: Report
System: The UNT Digital Library
Geothermal Direct-Heat Utilization Assistance - Final Report (open access)

Geothermal Direct-Heat Utilization Assistance - Final Report

The Geo-Heat Center provided (1) direct-use technical assistance, (2) research, and (3) information dissemination on geothermal energy over an 8 1/2 year period. The center published a quarterly bulletin, developed a web site and maintained a technical library. Staff members made 145 oral presentations, published 170 technical papers, completed 28 applied research projects, and gave 108 tours of local geothermal installations to 500 persons.
Date: July 14, 1999
Creator: Lund, J. W.
Object Type: Report
System: The UNT Digital Library
X-ray spectroscopy and imaging of a plasma collision (open access)

X-ray spectroscopy and imaging of a plasma collision

The collision of laser-produced plasmas has been diagnosed by x-ray spectroscopy and imaging. The two colliding plasmas are produced on Al thin foils at a distance of 200 to 900 {mu}m irradiated at {lambda} = 0.53 {mu}m with laser intensities of 3 {times} 10{sup 13} to 6 {times} 10{sup 13} W/cm{sup 2}. Interpenetration of the plasmas was visualized by replacing one of the foils material by magnesium. The main diagnostics viewing the inter-target space were time-resolved monochromatic imaging of the 1s{sup 2} 1s3p aluminum line (He{Beta} at {lambda} {minus} 6.635 {Angstrom}). Doppler broadening measurement with a vertical Johann very high resolution spectrograph in the range 6.5--6.7{Angstrom}, space-resolved high resolution spectra of the dielectronic satellites of the 1s-2p 1 yman, space-resolved spectra with a flat-crystal spectrograph in the range 5--7 {Angstrom} and in the range of 43--48 {Angstrom} obtained with a new OHM crystal spectrograph and a pinhole camera. A multifluid eulerian monodimensional hydrodynamic code coupled with a radiative-atomic package provided simulations of the experiments. Hydrodynamic 2D simulations calculating the lateral expansion of the plasma enabled a reliable treatment of reabsorption along the line of sight of the spectrographs. The size the time duration of the collision, the plasma parameters (Te,Ti …
Date: July 14, 1995
Creator: Chenais-Popovics, C.; Rancu, O. & Renaudin, P.
Object Type: Article
System: The UNT Digital Library
Experimental observations on electrorefining spent nuclear fuel in molten LiCl-KCl/liquid cadmium system. (open access)

Experimental observations on electrorefining spent nuclear fuel in molten LiCl-KCl/liquid cadmium system.

Argonne National Laboratory (ANL) is currently performing a demonstration program for the Department of Energy (DOE) which processes spent nuclear fuel from the Experimental Breeder Reactor (EBR-II). One of the key steps in this demonstration program is electrorefining of the spent fuel in a molten LiCl-KCl/liquid cadmium system using a pilot scale electrorefiner (Mk-IV ER). This article summarizes experimental observations and engineering aspects for electrorefining spent fuel in the molten LiCl-KCl/liquid cadmium system. It was found that the liquid cadmium pool acted as an intermediate electrode during the electrorefining process in the ER. The cadmium level was gradually decreased due to its high vapor pressure and vaporization rate at the ER operational temperature. The low cadmium level caused the anode assembly momentarily to touch the ER vessel hardware, which generated a periodic current change at the salt/cathode interface and improved uranium recovery efficiency for the process. The primary current distributions calculated by numerical simulations were used in interpreting the experimental results.
Date: July 14, 1999
Creator: Johnson, T. A.; Laug, D. V.; Li, S. X. & Sofu, T.
Object Type: Article
System: The UNT Digital Library
An overview of resid characterization by mass spectrometry and small angle scattering techniques. (open access)

An overview of resid characterization by mass spectrometry and small angle scattering techniques.

The purpose of this presentation is to discuss what is known about the molecular structures found in petroleum resid from mass spectrometry and small angle neutron and X-ray scattering methods. The question about molecular size distributions and the occurrence of aggregation in the asphaltene fraction will be examined. Our understanding of this problem has evolved with the application of new analytical methods. Also, correlations with results from other approaches will be discussed. In addition, the issue of the nature of the heteroatom-containing molecules will be examined and the challenges that remain in this area.
Date: July 14, 1999
Creator: Hunt, J. E. & Winans, R. E.
Object Type: Article
System: The UNT Digital Library
Investigation of particle/gas flow characteristics in pipelines. (open access)

Investigation of particle/gas flow characteristics in pipelines.

Gas-solid flows occur frequently in many industrial processes and systems, such as in pulverized coal transport pipelines and portions of fluid catalytic cracking (FCC) risers. Many of these systems have been modeled and optimized over the years by ''engineering know-how,'' which has been derived from the operating experience with the unit. However, it is being recognized that a more detailed, analytic tool is necessary to improve the efficiency of these systems due to heightened industrial competitiveness. In addition to this competition, increasingly stringent environmental regulations force the industry to improve their systems to comply with these regulations. In part, these two conditions explain the recent interest in computational fluid dynamics (CFD) applied to industrial systems. A successfully validated CFD simulation can provide detailed information on an industrial flow system based on a limited amount of experimental data. Once a CFD code has been properly validated, it may then be used to suggest optimal operating conditions. Given the wide range of information provided by a CFD code, the term ''optimal'' may refer to optimal material output, optimal energy efficiency, minimal (optimal) pollutant emission, or optimal lowest operating cost, for example. This versatility has been recently recognized by a number of industries …
Date: July 14, 1999
Creator: Golchert, B. M.
Object Type: Article
System: The UNT Digital Library
High SO{sub 2} removal efficiency testing. Quarterly status report, April-June 1995 (open access)

High SO{sub 2} removal efficiency testing. Quarterly status report, April-June 1995

This project involves testing at six full-scale utility flue gas desulfurization (FGD) systems to evaluate low capital cost upgrades that may allow these systems to achieve up to 98% SO{sub 2} removal efficiency. The upgrades being evaluated mostly involve using performance additives in the FGD systems. The {open_quotes}base{close_quotes} project involved testing at the Tampa Electric Company Big Bend station. All five potential options to the base program have been exercised by DOE, involving testing at Hoosier Energy`s Merom Station (Option I), Southwestern Electric Power Company`s Pirkey Station (Option II), PSI Energy`s Gibson Station (Option III), Duquesne Light`s Elrama Station (Option IV), and New York State Electric and Gas Corporation`s Kintigh Station (Option V). The originally planned testing has been completed for all six sites. The remainder of this document is divided into four sections. Section 2, Project Summary, provides a brief overview of the status of technical efforts on this project. Section 3, Results, summarizes the outcome from technical efforts during the quarter, or results from prior quarters that have not been previously reported. In Section 4, Plans for the Next Reporting Period, an overview is provided of the technical efforts that are anticipated for the third quarter of calendar …
Date: July 14, 1995
Creator: Blythe, G.
Object Type: Report
System: The UNT Digital Library
Use of high-temperature superconducting films in superconducting bearings. (open access)

Use of high-temperature superconducting films in superconducting bearings.

We have investigated the effect of high-temperature superconductor (HTS) films deposited on substrates that are placed above bulk HTSs in an attempt to reduce rotational drag in superconducting bearings composed of a permanent magnet levitated above the film/bulk HTS combination. According to the critical state model, hysteresis energy loss is inversely proportional to critical current density, J{sub c}, and because HTS films typically have much higher J{sub c} than that of bulk HTS, the film/bulk combination was expected to reduce rotational losses by at least one order of magnitude in the coefficient of fiction, which in turn is a measure of the hysteresis losses. We measured rotational losses of a superconducting bearing in a vacuum chamber and compared the losses with and without a film present. The experimental results showed that contrary to expectation, the rotational losses are increased by the film. These results are discussed in terms of flux drag through the film, as well as of the critical state model.
Date: July 14, 1999
Creator: Cansiz, A.
Object Type: Article
System: The UNT Digital Library
U.S. Russian cooperative efforts to enhance nuclear material protection, control, and accounting at the all Russian Scientific Research Institute of Technical Physics (VNIITF), Chelyabinsk 70 (open access)

U.S. Russian cooperative efforts to enhance nuclear material protection, control, and accounting at the all Russian Scientific Research Institute of Technical Physics (VNIITF), Chelyabinsk 70

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Date: July 14, 1998
Creator: Tsygankov, G., VNIITF, Chelyabinsk-70, Russia
Object Type: Article
System: The UNT Digital Library
Performance evaluation of bound diamond ring tools (open access)

Performance evaluation of bound diamond ring tools

LLNL is collaborating with the Center for Optics Manufacturing (COM) and the American Precision Optics Manufacturers Association (APOMA) to optimize bound diamond ring tools for the spherical generation of high quality optical surfaces. An important element of this work is establishing an experimentally-verified link between tooling properties and workpiece quality indicators such as roughness, subsurface damage and removal rate. In this paper, we report on a standardized methodology for assessing ring tool performance and its preliminary application to a set of commercially-available wheels. Our goals are to (1) assist optics manufacturers (users of the ring tools) in evaluating tools and in assessing their applicability for a given operation, and (2) provide performance feedback to wheel manufacturers to help optimize tooling for the optics industry. Our paper includes measurements of wheel performance for three 2-4 micron diamond bronze-bond wheels that were supplied by different manufacturers to nominally- identical specifications. Preliminary data suggests that the difference in performance levels among the wheels were small.
Date: July 14, 1995
Creator: Piscotty, M. A.; Taylor, J. S. & Blaedel, K. L.
Object Type: Article
System: The UNT Digital Library
Perspectives on Epic Physics (open access)

Perspectives on Epic Physics

An electron-proton/ion polarized beam collider (EPIC) with high luminosity and center of mass energy square root s = 25 GeV would be a valuable facility for fundamental studies of proton and nuclear structure and tests of quantum chromodynamics, I review a sample of prospective EPIC topics, particularly semi-exclusive reactions, studies of the proton fragmentation region, heavy quark electroproduction, and a new probe of odderon/pomeron interference.
Date: July 14, 1999
Creator: Brodsky, Stanley J.
Object Type: Report
System: The UNT Digital Library
Quarterly Technical Progress Report - West Hackberry Tertiary Project (open access)

Quarterly Technical Progress Report - West Hackberry Tertiary Project

The West Hackberry Tertiary Project is a field test of the concept that air injection can generate tertiary oil recovery through the Double Displacement Process is the gas displacement of a water invaded oil column for the purpose of recovering tertiary oil through gravity discharge. The novel aspect of this project is the use of air as the injection fluid.
Date: July 14, 1998
Creator: Yannimaras, Demetrios & Gillham, Travis
Object Type: Report
System: The UNT Digital Library
A facility for creating Python extensions in C++ (open access)

A facility for creating Python extensions in C++

Python extensions are usually created by writing the glue that connects Python to the desired new functionality in the C language. While simple extensions do not require much effort, to do the job correctly with full error checking is tedious and prone to errors in reference counting and to memory leaks, especially when errors occur. The resulting program is difficult to read and maintain. By designing suitable C++ classes to wrap the Python C API, we are able to produce extensions that are correct and which clean up after themselves correctly when errors occur. This facility also integrates the C++ and Python exception facilities. This paper briefly describes our package for this purpose, named CXX. The emphasis is on our design choices and the way these contribute to the construction of accurate Python extensions. We also briefly relate the way CXX's facilities for sequence classes allow use of C++'s Standard Template Library (STL) algorithms on C++ sequences.
Date: July 14, 1998
Creator: Dubois, P F
Object Type: Article
System: The UNT Digital Library
W1045 environment surf drip shield and waste package outer barrier (open access)

W1045 environment surf drip shield and waste package outer barrier

The environments on the drip shield and waste package outer barrier are controlled by the compositions of the waters that contact these components. the temperature (T) of these components, and the effective relative humidity (RH) at these components. Because the composition of the waters that are expected to enter the emplacement drifts (either by seepage flow or by episodic flow) have not been specified: well J13 water was chosen as the reference water (Harrar 1990). Section 6.2 discusses the accessible RH for the temperatures of interest at the repository horizon. Section 6.3 discusses the adsorption of water on metal alloys in the absence of hygroscopic salts. Because the temperatures of the DSs and the WPOBs are higher than those of the surrounding near-field environment, the relative humidity at the DSs and the WPOBs will be lower than that of the surrounding near-field environment. This difference is a result of the water partial pressure in the drift being constant and no higher than the equilibrium water vapor pressure at the temperature of the drift wall.
Date: July 14, 1999
Creator: Gdowski, G
Object Type: Report
System: The UNT Digital Library
Structural design criteria for high heat flux components. (open access)

Structural design criteria for high heat flux components.

The high temperature design rules of the ITER Structural Design Criteria (ISDC), are applied to first wall designs with high heat flux. The maximum coolant pressure and surface heat flux capabilities are shown to be determined not only by the mechanical properties of the first wall material but also by the details of the blanket design. In a high power density self-cooled lithium blanket, the maximum primary stress in the first wall is controlled by many of the geometrical parameters of the blanket, such as, first wall span, first wall curvature, first wall thickness, side wall thickness, and second wall thickness. The creep ratcheting lifetime of the first wall is also shown to be controlled by many of the same geometrical parameters as well as the coolant temperature. According to most high temperature design codes, the time-dependent primary membrane stress allowable are based on the average temperature (ignoring thermal stress). Such a procedure may sometimes be unconservative, particularly for embrittled first walls with large temperature gradients. The effect of secondary (thermal) stresses on the accumulation of creep deformation is illustrated with a vanadium alloy flat plate first wall design.
Date: July 14, 1999
Creator: Majumdar, S.
Object Type: Article
System: The UNT Digital Library
Modeling crystal-field interaction for f-elements in LaCl{sub 3}. (open access)

Modeling crystal-field interaction for f-elements in LaCl{sub 3}.

The results of crystal field calculations in the framework of exchange charge model (ECM) are reported for trivalent lanthanide and actinide ions doped into LaCl{sub 3}. Whereas the scalar strength of the model crystal field parameters are consistent with that previously determined by fitting the experimental data, the sign of the second-order parameter is found to be negative, in contrast to previous reports. The contribution from long-range electrostatic interactions exceeds that from the nearest neighboring ligands and leads to the negative sign of the second-order crystal field parameter. Other interaction mechanisms including overlap, covalence, and charge exchange are less important to the second order parameter, but dominate the fourth- and sixth-order parameters. This work provides a consistent interpretation of the previously controversial experimental results for both lanthanide and actinide ions in this classical host.
Date: July 14, 1997
Creator: Liu, G. K. & Zhorin, V. V.
Object Type: Article
System: The UNT Digital Library
Pressure fluctuations as a diagnostic tool for fluidized beds. Technical progress report, April 1--June 30, 1995 (open access)

Pressure fluctuations as a diagnostic tool for fluidized beds. Technical progress report, April 1--June 30, 1995

The first phase of experimentation for the comprehensive similitude study on the two laboratory scale cold-model circulating fluidized beds has been completed. This first phase required the acquisition and analysis of pressure fluctuation data from a 2.0 inch diameter pressurized circulating fluidized bed. The second phase required the matching of each of the 20 experiments in a cold-model twice the size of the smaller 2.0 inch circulating fluidized bed model using similitude relations. Problems of excessive electrostatic buildup were encountered in this second phase. To alleviate these problems, the large model had to be redesigned and reconstructed. The focus of the research this past quarter has been devoted to these modifications. Currently, the new sections have been constructed and the modified circulating fluidized bed is in the process of reassembly. Two related projects were undertaken while the large circulating fluidized bed model was being modified. A bubbling bed was constructed such that pressure fluctuation data could be measured in both bubbling and turbulent fluidization regimes. The purpose of such tests was to relate pressure fluctuation structure in the lower sections of the circulating fluidized bed with phenomena observed in bubbling/turbulent regimes. Two probes designed to measure heat transfer coefficients in …
Date: July 14, 1995
Creator: Brown, R.C.
Object Type: Report
System: The UNT Digital Library
Aging and phase stability of waste package outer barrier (open access)

Aging and phase stability of waste package outer barrier

After aging for 16,000 hr at 593 C, P phase was found at Alloy 22 grain boundaries. At higher temperatures (as much as 760 C for the same aging time), both {mu} and P phase formed on grain boundaries and within the grains. Grain boundary carbides also form at 593 C and higher, but the amount of carbide is small compared to the p and P phases. A small amount of sigma phase forms in Alloy 22 after 16,000 hr at 704 and 760 C. LRO was seen after aging for 16,000 hr at 593 C and for 40,000 hr at 427 C, but ordering most likely begins at shorter times. More work must be done in phase identification. Samples aged at times less than 16,000 hr must be examined so that the phase evolution during aging can be determined. A procedure being developed for phase extraction and x-ray diffraction should make phase identification and quantification of the relative amounts of each phase easier. The times at which various stages of intermetallic precipitation occur in Alloy 22 base metal displayed an exponential (Arrhenius-type) temperature dependence. The activation energy was determined to be 290 kJ/mol. A more quantitative model based on …
Date: July 14, 1999
Creator: Summers, T & Turchi, P
Object Type: Report
System: The UNT Digital Library
Design considerations for heated wells in gloveboxes. (open access)

Design considerations for heated wells in gloveboxes.

Heated wells in gloveboxes have been used for many years by the Argonne National Laboratory Chemical Technology Division for nuclear-technology, waste-management, chemical-technology, and analytical-chemistry research. These wells allow experiments to be isolated from the main working volume of the glovebox. In addition, wells, when sealed, allow experiments to be conducted under pressurized or vacuum conditions. Until recently, typical maximum operational temperatures were about 500 C. However, more recent research is requiring operational temperatures approaching 900 C. These new requirements pose interesting design challenges that must be resolved. Some problem areas include temperature effects on material properties, maintaining a seal, cooling selected areas, and minimizing stresses. This paper discusses issues related to these design challenges and the ways in which these issues have been resolved.
Date: July 14, 1999
Creator: Frigo, A. A. & Preuss, D. E.
Object Type: Article
System: The UNT Digital Library
XAF/XANES studies of plutonium-loaded sodalite/glass composite waste forms. (open access)

XAF/XANES studies of plutonium-loaded sodalite/glass composite waste forms.

A sodalite/glass ceramic waste form has been developed to immobilize highly radioactive nuclear wastes in chloride form, as part of an electrochemical cleanup process. Simulated waste forms have been fabricated which contain plutonium and are representative of the salt from the electrometallurgical process to recover uranium from spent nuclear fuel. X-ray absorption fine structure spectroscopy (XAFS) and x-ray absorption near-edge spectroscopy (XANES) studies were performed to determine the location, oxidation state and form of the plutonium within these waste forms. Plutonium, in the non-fission-element case, was found to segregate as plutonium(IV) oxide with a crystallite size of at least 20 nm. With fission elements present, the crystallite size was about 2 nm. No plutonium was observed within the sodalite or glass in the waste form.
Date: July 14, 1999
Creator: Aase, S. B.; Kropf, A. J.; Lewis, M. A.; Reed, D. T. & Richmann, M. K.
Object Type: Article
System: The UNT Digital Library