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Extensions to the VME hardware and software standards for the physics community
With the ubiquitous availability of commercial VME modules and interface chips many experiments in all branches of Experimental Physics are turning to VME as the module packaging and backplane protocol of choice for application specific modules. The current VME backplane, electrical, and mechanical standards are clearly lacking when it comes to implementing the analogue and digital front end modules that Physics experiments rely on to provide the needed high speed and intelligent solutions to their data collection requirements. To address these needs the European ESONE and American VME-P committees are collaborating with the ANSII and ISO standards committees, and the VME VITA/VSO manufacturers associations, to define standard extensions to the VME protocols for such HEP needs as ``sparse data scans``, standard uses and implementations of previously user defined pins and connectors, standardization of the 9U form factor VME cards etc. This paper reports on the current status and directions of this standards effort.
Date:
October 1, 1995
Creator:
Pordes, R.
System:
The UNT Digital Library
Proliferation resistance criteria for fissile material disposition issues
The 1994 National Acdaemy of Sciences study ``Management and Disposition of Excess Weapons Plutonium`` defined options for reducing the national and international proliferation risks of materials declared excess to the nuclear weapons program. This paper proposes criteria for assessing the proliferation resistance of these options as well defining the ``Standards`` from the report. The criteria are general, encompassing all stages of the disposition process from storage through intermediate processing to final disposition including the facilities, processing technologies and materials, the level of safeguards for these materials, and the national/subnational threat to the materials.
Date:
September 1, 1995
Creator:
Rutherford, D. A.; Fearey, B. L.; Markin, J. T.; Close, D. A.; Tolk, K. M.; Mangan, D. L. et al.
System:
The UNT Digital Library
Interactive computer code for dynamic and soil structure interaction analysis
A new interactive computer code is presented in this paper for dynamic and soil-structure interaction (SSI) analyses. The computer program FETA (Finite Element Transient Analysis) is a self contained interactive graphics environment for IBM-PC`s that is used for the development of structural and soil models as well as post-processing dynamic analysis output. Full 3-D isometric views of the soil-structure system, animation of displacements, frequency and time domain responses at nodes, and response spectra are all graphically available simply by pointing and clicking with a mouse. FETA`s finite element solver performs 2-D and 3-D frequency and time domain soil-structure interaction analyses. The solver can be directly accessed from the graphical interface on a PC, or run on a number of other computer platforms.
Date:
December 1, 1995
Creator:
Mulliken, J.S.
System:
The UNT Digital Library
Lattice determinations of the strange quark mass
The importance of the strange quark mass, as a fundamental parameter of the Standard Model (SM) and as an input to many interesting quantities, has been highlighted in many reviews, eg in Ref [1]. A first principles calculation of m{sub s} is possible in lattice QCD but to date there has been a rather large spread in values from lattice calculations. This review aims to clarify the situation by explaining the particular systematic errors and their effects and illustrating the emerging consensus. In addition, a discussion of the strange quark mass is timely given the recent results from KTeV [2] and NA48 [3] for {epsilon}{prime}/{epsilon} which firmly establish direct CP-violation in the SM and when combined with previous measurements give a world average {epsilon}{prime}/{epsilon} (21:2 {+-} 2:8) x 10{sup {minus}4}. This is in stark disagreement with the theoretical predictions which favor a low {epsilon}{prime}/{epsilon} [4]. Although in principle {epsilon}{prime}/{epsilon} does not depend directly on m{sub s} in practice it has been an input in current phenomenological analyses. This dependence arises because the matrix elements of the gluonic, <Q{sub 6}>{sub 0}, and electroweak, <Q{sub 8}>{sub 2}, penguin operators are of the form <{pi}{pi}{vert_bar}Q{sub i}{vert_bar}K> and final state interactions make them notoriously …
Date:
August 25, 1999
Creator:
Ryan, Sinead
System:
The UNT Digital Library
High-lift chemical heat pump technologies for industrial processes
Traditionally industrial heat pumps (IHPs) have found applications on a process specific basis with reject heat from a process being upgraded and returned to the process. The IHP must be carefully integrated into a process since improper placement may result in an uneconomic application. Industry has emphasized a process integration approach to the design and operation of their plants. Heat pump applications have adopted this approach and the area of applicability was extended by utilizing a process integrated approach where reject heat from one process is upgraded and then used as input for another process. The DOE IHP Program has extended the process integration approach of heat pump application with a plant utility emphasis. In this design philosophy, reject heat from a process is upgraded to plant utility conditions and fed into the plant distribution system. This approach has the advantage that reject heat from any pr@s can be used as input and the output can be used at any location within the plant. Thus the approach can be easily integrated into existing industrial applications and all reject heat streams are potential targets of opportunity. The plant utility approach can not be implemented without having heat pumps with high-lift capabilities …
Date:
March 1995
Creator:
Olszewski, M. & Zaltash, A.
System:
The UNT Digital Library
Applications of Virtual Reality to Nuclear Safeguards
This paper explores two potential applications of Virtual Reality (VR) to international nuclear safeguards: training and information organization and navigation. The applications are represented by two existing prototype systems, one for training nuclear weapons dismantlement and one utilizing a VR model to facilitate intuitive access to related sets of information.
Date:
November 3, 1998
Creator:
Stansfield, S.
System:
The UNT Digital Library
Building the Teraflops/Petabytes Production Computing Center
In just one decade, the 1990s, supercomputer centers have undergone two fundamental transitions which require rethinking their operation and their role in high performance computing. The first transition in the early to mid-1990s resulted from a technology change in high performance computing architecture. Highly parallel distributed memory machines built from commodity parts increased the operational complexity of the supercomputer center, and required the introduction of intellectual services as equally important components of the center. The second transition is happening in the late 1990s as centers are introducing loosely coupled clusters of SMPs as their premier high performance computing platforms, while dealing with an ever-increasing volume of data. In addition, increasing network bandwidth enables new modes of use of a supercomputer center, in particular, computational grid applications. In this paper we describe what steps NERSC is taking to address these issues and stay at the leading edge of supercomputing centers.
Date:
September 1, 1999
Creator:
Kramer, William T.C.; Lucas, Don & Simon, Horst D.
System:
The UNT Digital Library
Phase transitions in ammonium perchlorate to 26 GPA and 700 K in a diamond anvil cell
Ammonium perchlorate (AP) showed previously unreported phase behavior when studied in a diamond anvil cell (DAC) at high temperature (to 693 K) and high pressure (to {approximately}26 GPa). Liquid droplets, observed above the known 513 K orthorhombic-to-cubic phase transition, are interpreted as the onset to melting. The melting point decreased with increasing pressure. Mid-infrared FTIR spectra of the residue showed only AP. The AP melt may contribute to shock insensitivity of AP-based propellants. Gas formation was seen at higher temperatures. A phase diagram was constructed using the appearance of liquid and gas as solid-liquid and liquid-gas transitions. Preliminary pressurized differential scanning calorimetry data showed a weak pressure dependence (to {approximately}6.9 MPa) for the orthorhombic-to-cubic phase transition.
Date:
July 10, 1995
Creator:
Foltz, M.F. & Maienschein, J.L.
System:
The UNT Digital Library
Indirect liquefaction of biomass: A fresh approach
Indirect liquefaction of biomass is accomplished by first gasifying it to produce a synthesis gas consisting of hydrogen and oxides of carbon, which in turn are converted to any one of a number of liquid fuels and/or chemicals by suitable choice of catalyst, synthesis gas composition and reaction conditions. This approach to producing synthetic fuels and chemicals has been extensively investigated where coal is the carbonaceous feed material, but less so for biomass or other feedstocks. It is generally recognized that the gasification to produce the synthesis gas posses one of the major technical and economic challenges to improving this technology. Herein, is reported a different slant on the indirect liquefaction that could lead to improvements in the efficiency and economics of the process.
Date:
August 1, 1995
Creator:
Cox, J. L.; Tonkovich, A. Y. & Elliott, D. C.
System:
The UNT Digital Library
Phonon density of states in Fe/Cr (001) superlattices and Tb-Fe thin-film alloys.
Inelastic nuclear scattering of X-rays from the 14.413 keV nuclear resonance of {sup 57}Fe was employed to measure directly the Fe-projected phonon density of states (DOS) in MBE-grown Fe/Cr(00l) superlattices on MgO(001). The Moessbauer-inactive {sup 56}Fe isotope was used in the Fe layers. A 1{angstrom} thick Moessbauer-active {sup 57}Fe-probe layer (95% enriched) was placed at different locations within the Fe layers. This procedure permits one to distinguish phonon density of states at the Fe-Cr-interface from that at the center of the Fe-film. Distinct differences have been observed in the DOS of our samples. The phonon DOS of an amorphous Tb{sub 33}Fe{sub 67} alloy film was found to be a broad and structureless hump, contrary to that of an epitaxial TbFe{sub 2} film, which exhibits characteristic features.
Date:
February 15, 1999
Creator:
Alp, E. E.; Keune, W.; Roehlsberger, R.; Ruckert, T.; Schror, H. & Sturhahn, W.
System:
The UNT Digital Library
Hard diffraction
An introduction to the rapidly developing subject of diffractive processes containing jets is given, with emphasis on an s-channel picture of the dynamics.
Date:
March 1, 1994
Creator:
Bjorken, J. D.
System:
The UNT Digital Library
The status of APS, BESSRC, and NEET.
We present a brief summary of the current status of the Advanced Photon Source (APS) at Argonne National Laboratory and of the facilities at two of the APS sectors operated by the Basic Energy Sciences Synchrotrons Radiation Center (BESSRC). This is followed by a report on recent measurements at BESSRC on the phenomenon of Nuclear Excitation by Electronic Transition (NEET).
Date:
March 10, 1999
Creator:
Ahmad, I.; Dunford, R. W.; Esbensen, H.; Gemmell, D. S.; Kanter, E. P.; Kraessig, B. et al.
System:
The UNT Digital Library
Search for new physics in D{+-} {r_arrow} K{sub s}X{+-} and D{+-} {r_arrow} K{sub s}K{sub s}K{+-}.
Direct CP violation beyond the standard model can be produced in charged D decays to final states with a K{sub S} by small new physics contributions to the transitions D{sup +} {r_arrow} K{sup 0}X{sup +}, where X{sup +} denotes any positively charged hadronic state or transitions D{sup +} {r_arrow} K{sup 0}{bar K}{sup 0}K{sup (*)+}, denotes any positive strange state. These transitions are doubly-Cabibbo suppressed and color suppressed in the standard model and branching ratios are experimentally observed to be suppressed by two orders of magnitude relative to the allowed D{sup +} {r_arrow} {bar K}{sup 0}X{sup +} or D{sup +} {r_arrow} {bar K}{sup 0}{bar K}{sup 0}K{sup (*)+}, branching ratio. An even smaller new physics contribution might produce an observable CP asymmetry in D{sup {+-}} {r_arrow} K{sub S}X{sup {+-}} or D{sup {+-}} {r_arrow} K{sub S}K{sub S}K{sup (*){+-}} decays. Since such asymmetries are easily checked in the early stages of any charm production experiment, it seems worth while to check them before the opportunity is lost in later stages of the analysis, even if no theoretical model predicts such an asymmetry.
Date:
November 9, 1998
Creator:
Lipkin, H. J.
System:
The UNT Digital Library
Properties of b {anti b} Production at the Tevatron
The authors present a number of recent results obtained at the Fermilab Tevatron for b{bar b} production in p{bar p} interactions. The preliminary CDF and D0 measurements of the inclusive b-quark production cross section at {radical}s = 630 GeV are compared with the UA1 results and the next-to-leading order QCD predictions. These results are used to compute the ratio of the cross sections at 630 GeV to 1800 GeV. The CDF results on the B meson differential cross section and {Lambda}{sub b}{sup 0} baryon production and decay properties at {radical}s = 1800 GeV are also presented.
Date:
May 1, 1997
Creator:
Stichelbaut, Frederic
System:
The UNT Digital Library
How far from stability can we go using gammasphere and the FMA?
This paper presents new results obtained using the US national gamma-ray facility Gammasphere, which has been operating at the ATLAS accelerator at Argonne National Laboratory since January 1998. Gammasphere was built at Lawrence Berkeley Laboratory and used primarily as a powerful spectrometer for studying nuclei at the highest spins. For pioneering research in the high-spin regime, it was constructed with high photopeak efficiency (about 10% for 1.33 MeV gamma-rays), good energy resolution (< 2.4 keV at 1.33 meV), good photopeak-to-total response (> 55% of 1.33 MeV events are in the photopeak) and high granularity (> 100 high-purity germanium (HpGe) detector channels, of which 65 are segmented, to allow precise Doppler correction and minimize the chance of double-hits). The device has a high degree of mechanical symmetry which is ideal for angular correlation studies. The whole spectrometer, both HpGe detectors and their BGO anti-Compton shields, can be used for photon calorimetry by adding the energy deposited in the nearly 900 active elements.
Date:
January 19, 1999
Creator:
Lister, C. J.
System:
The UNT Digital Library
Using modern software tools to design, simulate and test a Level 1 trigger sub-system for the D Zero Detector
This paper describes a system which uses a commercial spreadsheet program and commercial hardware on an IBM PC to develop and test a track finding system for the D Zero Level 1 scintillating Fiber Trigger. The trigger system resides in a VME crate. This system allows the user to generate test input, write the pattern to the hardware simulate the results in software, read the hardware result: compare the results and inform the user of any differences.
Date:
June 1, 1995
Creator:
Angstadt, R.; Borcherding, F.; Johnson, M. E. & Moreira, L.
System:
The UNT Digital Library
Characterization of liquid-water percolation in tuffs in the unsaturated zone, Yucca Mountain, Nye County, Nevada
A surface-based borehole investigation currently (1989) is being done to characterize liquid-water percolation in tuffs of Miocene age in the unsaturated zone beneath Yucca Mountain, Nye County, Nevada Active in-situ testing and passive in-situ monitoring will be used in this investigation to estimate the present-day liquid-water percolation (flux). The unsaturated zone consists of a gently dipping sequence of fine-grained, densely fractured, and mostly welded ash-flow tuffs that are interbedded with fine-grained, slightly fractured, non-welded ash-flow and ash-fall tuffs that are partly vitric and zeolitized near the water table. Primary study objectives are to define the water potential field within the unsaturated zone and to determine the in-situ bulk permeability and bulk hydrologic properties of the unsaturated tuffs. Borehole testing will be done to determine the magnitude and spatial distribution of physical and hydrologic properties of the geohydrologic units, and of their water potential fields. The study area of this investigation is restricted to that part of Yucca Mountain that immediately overlies and is within the boundaries of the perimeter drift of a US Department of Energy proposed mined, geologic, high-level radioactive-waste repository. Vertically, the study area extends from near the surface of Yucca Mountain to the underlying water table, about …
Date:
December 31, 1989
Creator:
Kume, J. & Rousseau, J.P.
System:
The UNT Digital Library
Water-rock interactions and the pH stability of groundwater from Yucca Mountain, Nevada
Titrations of acidic solutions in waters from the tuff and carbonate aquifers at Yucca Mountain were simulated using the geochemical codes PHREEQE and EQ3/6. The simulations tested pH stability of the waters in the presence of different minerals and in their absence. Two acidic solutions, 10{sup {minus}4} HCl and 10{sup {minus}4}M UO{sub 2}(NO{sub 3}){sub 2}, were titrated in to the water. Little pH and/or compositional change resulted in the groundwater when the HCl solution was titrated, but significant pH and CO{sub 2} fugacity changes were observed when UO{sub 2}(NO{sub 3}){sub 2} was titrated. Water interactions with alkali feldspar, quartz or cristobalite, and Ca-smectite buffered the pH and compositional changes in the carbonate water and decreased the magnitude of pH and compositional changes when small volumes of UO{sub 2}(NO{sub 3}){sub 2} added to the tuffaceous waters.
Date:
June 1, 1992
Creator:
Ebinger, M.H.
System:
The UNT Digital Library
Mechanistic interpretation of glass reaction: Input to kinetic model development
Actinide-doped SRL 165 type glass was reacted in J-13 groundwater at 90{degree}C for times up to 278 days. The reaction was characterized by both solution and solid analyses. The glass was seen to react nonstoichiometrically with preferred leaching of alkali metals and boron. High resolution electron microscopy revealed the formation of a complex layer structure which became separated from the underlying glass as the reaction progressed. The formation of the layer and its effect on continued glass reaction are discussed with respect to the current model for glass reaction used in the EQ3/6 computer simulation. It is concluded that the layer formed after 278 days is not protective and may eventually become fractured and generate particulates that may be transported by liquid water. 5 refs., 5 figs. , 3 tabs.
Date:
May 1, 1991
Creator:
Bates, J. K.; Ebert, W. L.; Bradley, J. P. & Bourcier, W. L.
System:
The UNT Digital Library
The EQ3/6 software package for geochemical modeling: Current status
EQ3/6 is a software package for modeling chemical and mineralogic interactions in aqueous geochemical systems. The major components of the package are EQ3NR (a speciation-solubility code), EQ6 (a reaction path code), EQLIB (a supporting library), and a supporting thermodynamic data base. EQ3NR calculates aqueous speciation and saturation indices from analytical data. It can also be used to calculate compositions of buffer solutions for use in laboratory experiments. EQ6 computes reaction path models of both equilibrium step processes and kinetic reaction processes. These models can be computed for closed systems and relatively simple open systems. EQ3/6 is useful in making purely theoretical calculations, in designing, interpreting, and extrapolating laboratory experiments, and in testing and developing submodels and supporting data used in these codes. The thermodynamic data base supports calculations over the range 0-300{degree}C. 60 refs., 2 figs.
Date:
July 1, 1988
Creator:
Wolery, T. J.; Jackson, K. J.; Bourcier, W. L.; Bruton, C. J.; Viani, B. E.; Knauss, K. G. et al.
System:
The UNT Digital Library
Diffusion, precipitation, and cavity-wall reactions of ion-implanted gold in silicon
The diffusion of Au in Si and its binding to cavities and precipitates of the equilibrium Au-Si phase were investigated in the temperature range 1023-1123 K using ion implantation and Rutherford backscattering spectrometry. The diffusivity-solubility product for interstitial Au was found to be about an order of magnitude greater than the extrapolation of previous, less direct determinations at higher temperatures. Chemisorption on cavity walls was shown to be more stable than Au-Si precipitation by 0.1-0.2 eV in the investigated temperature range, indicating that cavities are effective gettering centers for Au impurities.
Date:
December 31, 1995
Creator:
Myers, S. M. & Petersen, G. A.
System:
The UNT Digital Library
The effect of grain shape on strength variability of alumina ceramics
Fine-grained and coarse-grained aluminas containing either equiaxed or elongated grain structures were fabricated from commercial-purity and high-purity alumina powders. Compared to the high-purity aluminas, the commercial-purity aluminas having a coarse grain size and elongated grain structures exhibited significantly more pronounced flaw tolerance and T-curve behavior. T-curve behavior determined from indentation strength tests suggested that only the coarse- grained, elongated-grain alumina had a T-curve sufficient to cause stable crack extension prior to failure, a requirement for any observable improvement in reliability. In the high-purity aluminas as well as the fine-grained commercial-purity aluminas, however, it is likely that little or no stable extension occurs prior failure, suggesting that strength in these materials is dependent on the critical flaw size. Strength tests on polished specimens showed the commercial-purity aluminas had a lower means strength than the high- purity aluminas and the coarse-grained aluminas exhibited a lower mean strength compared to the fine-grained aluminas. An analysis of the mean strength versus grain size revealed that the differences in critical flaw size alone could not account for the differences in mean strength. Instead, a combination of changes in flaw size as well as T-curve behavior were shown to be responsible for the differences in strength …
Date:
October 1, 1995
Creator:
Readey, M.J.
System:
The UNT Digital Library
Treatment Deployment Evaluation Tool
The U.S. Department of Energy (DOE) is responsible for the final disposition of legacy spent nuclear fuel (SNF). As a response, DOE's National Spent Nuclear Fuel Program (NSNFP) has been given the responsibility for the disposition of DOE-owned SNF. Many treatment technologies have been identified to treat some forms of SNF so that the resulting treated product is acceptable by the disposition site. One of these promising treatment processes is the electrometallurgical treatment (EMT) currently in development; a second is an Acid Wash Decladding process. The NSNFP has been tasked with identifying possible strategies for the deployment of these treatment processes in the event that a treatment path is deemed necessary. To support the siting studies of these strategies, economic evaluations are being performed to identify the least-cost deployment path. This model (tool) was developed to consider the full scope of costs, technical feasibility, process material disposition, and schedule attributes over the life of each deployment alternative. Using standard personal computer (PC) software, the model was developed as a comprehensive technology economic assessment tool using a Life-Cycle Cost (LCC) analysis methodology. Model development was planned as a systematic, iterative process of identifying and bounding the required activities to dispose of …
Date:
August 1, 1999
Creator:
Rynearson, M. A. & Plum, M. M.
System:
The UNT Digital Library
Electrochemical properties of mixed conducting La{sub 1{minus}x}M{sub x}Co{sub 1{minus}y}Fe{sub y}O{sub 3{minus}{delta}} (M = Sr,Ca,Ba) perovskites
At elevated temperatures, some ABO{sub 3} perovskite type oxides having Co and Fe as B site cations exhibit substantial mixed (anionic and electronic) conductivity. Because of this behavior, they are candidate materials for applications such as solid oxide fuel cell cathodes and oxygen separation membranes. The purpose of the present study is to increase the understanding of the effects of composition, temperature, and environment on the electrochemical properties of selected materials within the La{sub 1{minus}x}M{sub x}Co{sub 1{minus}y}Fe{sub y}O{sub 3{minus}{delta}} (M=Sr,Ca,Ba) system in order to evaluate their applicability for the above-mentioned applications. Characterization techniques include XRD, SEM, TGA, dc conductivity, dilatometry, oxygen permeation measurements, and iodometric titration.
Date:
October 1, 1995
Creator:
Stevenson, J. W.; Armstrong, T. R.; Pederson, L. R. & Weber, W. J.
System:
The UNT Digital Library