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A Preliminary measurement of the gluon splitting rate into b\bar{b} pairs in hadronic Z0 decays
We present a measurement of the rate of gluon splitting into bottom quarks, g --> b anti-b, in hadronic Z<sup>0</sup> decays collected by SLD from 1996 to 1998. The analysis was performed by looking for secondary bottom production in 4-jet events of any primary avor. A topological vertex mass technique was used to tag the two jets with the smallest angle between them as b/anti-b. We obtained a rate of g --> b anti-b per hadronic event to be (3.07 ± 0.71(stat:) ± 0.66(syst:)) × 10³ (preliminary).
Date:
June 10, 1999
Creator:
Abe, Toshinori
Object Type:
Report
System:
The UNT Digital Library
Analysis of Ignition Testing on K-West Basin Fuel
Approximately 2100 metric tons of spent nuclear fuel (SNF) discharged from the N-Reactor have been stored underwater at the K-Basins in the 100 Area of the Hanford Site. The spent fuel has been stored in the K-East Basin since 1975 and in the K-West Basin since 1981. Some of the SNF elements in these basins have corroded because of various breaches in the Zircaloy cladding that occurred during fuel discharge operations and/or subsequent handling and storage in the basins. Consequently, radioactive material in the fuel has been released into the basin water, and water has leaked from the K-East Basin into the soil below. To protect the Columbia River, which is only 380 m from the basins, the SNF is scheduled to be removed and transported for interim dry storage in the 200 East Area, in the central portion of the Site. However, before being shipped, the corroded fuel elements will be loaded into Multi-Canister OverPacks and conditioned. The conditioning process will be selected based on the Integrated Process Strategy (IPS) (WHC 1995), which was prepared on the basis of the dry storage concept developed by the Independent Technical Assessment (ITA) team (ITA 1994).
Date:
August 10, 1999
Creator:
Abrefah, J.; Huang, F.H.; Gerry, W.M.; Gray, W.J.; Marschman, S.C. & Thornton, T.A.
Object Type:
Report
System:
The UNT Digital Library
Analysis of Ignition Testing on K-West Basin Fuel
Ignition tests and analyses of damage/corroded N-Reactor spent nuclear fuel (SNF) were performed by Pacific Northwest National Laboratory as part of a series of studies on the deteriorating spent fuel in the Hanford K-Basins. The ignition temperature tests were conducted to assess tie pyrophoric properties of selected spent fuel elements from K-West Basin. The objective of these tests was to determine pyrophoric characteristics of samples cut from both damaged and undamaged regions of fhel elements. Furnace ignition tests were also petiormed on samples subjected to the conditioning process proposed by the Independent Technical Assessment and the Integrated Process Strategy to establish any significant effect on the SNF pyrophoric pefiormance parameters. Part of the analysis of the ignition data in this report was petiormed by FIuor Daniel Northwest. One of the safety issues being evaluated is the possibility of a fiel ignition during processing, handling, and transportation to the interim storage facility.
Date:
August 10, 1999
Creator:
Abrefah, John; Huang, Fan-Hsiung F.; Gerry, William M.; Gray, Walter J.; Marschman, Steven C. & Thornton, Thomas A.
Object Type:
Report
System:
The UNT Digital Library
Theory of high-{Tc} superconducting cuprates based on experimental evidence
A model of superconductivity in layered high-temperature superconducting cuprates is proposed, based on the extended saddle point singularities in the electron spectrum, weak screening of the Coulomb interaction and phonon-mediated interaction between electrons plus a small short-range repulsion of Hund's, or spin-fluctuation, origin. This permits to explain the large values of {Tc}, features of the isotope effect on oxygen and copper, the existence of two types of the order parameter, the peak in the inelastic neutron scattering, the positive curvature of the upper critical field, as function of temperature etc.
Date:
December 10, 1999
Creator:
Abrikosov, A. A.
Object Type:
Article
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.
Object Type:
Article
System:
The UNT Digital Library
An x-ray fluorescence study of lake sediments from ancient Turkey using synchrotron radiation.
Sediments from relic Lake Golbasi were analyzed by X-ray fluorescence with synchrotrons radiation to determine changes in element concentrations over time with selected elements serving as proxies for environmental change. Increases in Ca and Sr suggest soil formation during a dry period, from ca. 4500 BC to ca. 200 AD at which point K, Rb, Zr, Ti, and Y increase, indicating the return of a wet environment. Soil erosion, represented by Cr and Ni, increases ca. 7000 BC, probably as a consequence of environmental change, prior to suggested exploitation of natural resources by the newly urbanized society of the third millennium BC.
Date:
March 10, 1999
Creator:
Alatas, A.; Alp, E. E.; Friedman, E. S.; Jennings, G.; Johnson, C. E.; Lai, B. et al.
Object Type:
Article
System:
The UNT Digital Library
The Oklahoma Daily (Norman, Okla.), Vol. 83, No. 102, Ed. 1 Wednesday, February 10, 1999
Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.
Date:
February 10, 1999
Creator:
Allam, Heather
Object Type:
Newspaper
System:
The Gateway to Oklahoma History
The Oklahoma Daily (Norman, Okla.), Vol. 83, No. 122, Ed. 1 Wednesday, March 10, 1999
Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.
Date:
March 10, 1999
Creator:
Allam, Heather
Object Type:
Newspaper
System:
The Gateway to Oklahoma History
Behavior of nanocrystalline Xe precipitates in Al under 1 MeV electron irradiation.
Crystalline nanoprecipitates of Xe have been produced by ion implantation into high purity Al at 300 K. With an off-zone axis TEM imaging technique, the nanocrystals may be clearly structure imaged against a nearly featureless background. Under the 1 MeV electron irradiation employed for the HREM observation, Xe nanocrystals exhibit a number of readily observed physical phenomena including migration within the matrix, changes in shape, faulting, melting, crystallization and coalescence. The various phenomena observed as changes in the Xe nanocrystals reflect changes of matrix cavity-surface structure. The Xe nanocrystal thus allows investigation indirectly into changes in interface morphology at the atomic level, resulting in this instance from electron irradiation damage. Such changes have heretofore been inaccessible to observation.
Date:
March 10, 1999
Creator:
Allen, C. W.; Birtcher, R. C.; Donnelly, S. E.; Furuya, K.; Mitsuishi, K. & Song, M.
Object Type:
Article
System:
The UNT Digital Library
Observation of an elementary cuboctahedron of Xe nanocrystal in an Al matrix.
When a noble gas element such as Xe is implanted in an fcc metal matrix such as Al at room temperature, a fine dispersion of precipitates forms. The precipitates are elementary fcc crystals up to diameters of several nanometers (for Xe in Al, 8-10 rim), above which they are non-crystalline. The precipitates exhibit a cube-on-cube orientation relation with the matrices and have lattice parameters which are much larger than those of the matrices (a{sub Xe} = 1.5a{sub Al}). Thus the interphase interfaces are incommensurate though the lattices are isotactic. The precipitates assume the shape of matrix cavities; for an Al matrix, at equilibrium this is a cuboctahedron, a {r_brace}111{l_brace} octahedron truncated at the corners on {l_brace}100{r_brace}. Fig. 1 is a sketch of a dispersion of such cuboctahedra, viewed approximately along a {l_angle}110{r_angle}. For this study specimens were prepared in the HVEM-Tandem Facility at Argonne National Laboratory by implanting 35 keV Xe to a dose of 4x10{sup 19} m{sup {minus}2} into well-annealed 5N Al discs which had been thinned by jet electropolishing. The range of the implant is approximately 25 nm. Specimens were examined at high resolution in the JEOL ARM-1000 high voltage electron microscope (HVEM) at the High Resolution Beam …
Date:
March 10, 1999
Creator:
Allen, C. W.; Birtcher, R. C.; Donnelly, S. E.; Furuya, K.; Ryan, E. A. & Song, M.
Object Type:
Article
System:
The UNT Digital Library
Neural Network-Based Resistance Spot Welding Control and Quality Prediction
This paper describes the development and evaluation of neural network-based systems for industrial resistance spot welding process control and weld quality assessment. The developed systems utilize recurrent neural networks for process control and both recurrent networks and static networks for quality prediction. The first section describes a system capable of both welding process control and real-time weld quality assessment, The second describes the development and evaluation of a static neural network-based weld quality assessment system that relied on experimental design to limit the influence of environmental variability. Relevant data analysis methods are also discussed. The weld classifier resulting from the analysis successfldly balances predictive power and simplicity of interpretation. The results presented for both systems demonstrate clearly that neural networks can be employed to address two significant problems common to the resistance spot welding industry, control of the process itself, and non-destructive determination of resulting weld quality.
Date:
July 10, 1999
Creator:
Allen, J.D., Jr.; Ivezic, N.D. & Zacharia, T.
Object Type:
Article
System:
The UNT Digital Library
Neural Network method for Inverse Modeling of Material Deformation
A method is described for inverse modeling of material deformation in applications of importance to the sheet metal forming industry. The method was developed in order to assess the feasibility of utilizing empirical data in the early stages of the design process as an alternative to conventional prototyping methods. Because properly prepared and employed artificial neural networks (ANN) were known to be capable of codifying and generalizing large bodies of empirical data, they were the natural choice for the application. The product of the work described here is a desktop ANN system that can produce in one pass an accurate die design for a user-specified part shape.
Date:
July 10, 1999
Creator:
Allen, J.D., Jr.; Ivezic, N.D. & Zacharia, T.
Object Type:
Article
System:
The UNT Digital Library
Cross-Sectional Scanning Tunneling Microscopy of InAsSb/InAsP Superlattices
Cross-sectional scanning tunneling microscopy has been used to characterize compositional structure in InAs{sub 0.87}Sb{sub 0.13}/InAs{sub 0.73}P{sub 0.27} and InAs{sub 0.83}Sb{sub 0.17}/InAs{sub 0.60}P{sub 0.40} strained-layer superlattice structures grown by metal-organic chemical vapor deposition. High-resolution STM images of the (110) cross section reveal compositional features within both the InAs{sub x}Sb{sub 1{minus}x} and InAs{sub y}P{sub 1{minus}y} alloy layers oriented along the [{bar 1}12] and [1{bar 1}2] directions--the same as those in which features would be observed for CuPt-B type ordered alloys. Typically one variant dominates in a given area, although occasionally the coexistence of both variants is observed. Furthermore, such features in the alloy layers appear to be correlated across heterojunction interfaces in a manner that provides support for III-V alloy ordering models which suggest that compositional order can arise from strain-induced order near the surface of an epitaxially growing crystal. Finally, atomically resolved (1{bar 1}0) images obtained from the InAs{sub 0.87}Sb{sub 0.13}/InAs{sub 0.73}P{sub 0.27} sample reveal compositional features in the [112] and [{bar 1}{bar 1}2] directions, i.e., those in which features would be observed for CuPt-A type ordering.
Date:
February 10, 1999
Creator:
Allerman, A. A.; Biefeld, R. M.; Yu, E. T. & Zuo, S. L.
Object Type:
Article
System:
The UNT Digital Library
Developing a CD-CBM Anticipatory Approach for Cavitation - Defining a Model Descriptor Consistent Between Processes
A major problem with cavitation in pumps and other hydraulic devices is that there is no effective method for detecting or predicting its inception. The traditional approach is to declare the pump in cavitation when the total head pressure drops by some arbitrary value (typically 3o/0) in response to a reduction in pump inlet pressure. However, the pump is already cavitating at this point. A method is needed in which cavitation events are captured as they occur and characterized by their process dynamics. The object of this research was to identify specific features of cavitation that could be used as a model-based descriptor in a context-dependent condition-based maintenance (CD-CBM) anticipatory prognostic and health assessment model. This descriptor was based on the physics of the phenomena, capturing the salient features of the process dynamics. An important element of this concept is the development and formulation of the extended process feature vector @) or model vector. Thk model-based descriptor encodes the specific information that describes the phenomena and its dynamics and is formulated as a data structure consisting of several elements. The first is a descriptive model abstracting the phenomena. The second is the parameter list associated with the functional model. The …
Date:
May 10, 1999
Creator:
Allgood, G. O.; Dress, W. B. & Kercel, S. W.
Object Type:
Article
System:
The UNT Digital Library
Development and evaluation of high resolution quadrupole mass analyzer and an inductively coupled plasma-Mach disk
By definition a plasma is an electrically conducting gaseous mixture containing a significant concentration of cations and electrons. The Inductively Coupled Plasma (ICP) is an electrodeless discharge in a gas at atmospheric pressure. This discharge is an excellent one for vaporizing, atomizing, and ionizing elements. The early development of the ICP began in 1942 by Babat and then by Reed in the early 1960s. This was then followed by the pioneering work of Fassel and coworkers in the late 1960s. Commercial ICP spectrometers were introduced in the mid 1970s. A major breakthrough in the area of ICP took place in the early 1980s when the ICP was shown to be an excellent ion source for mass spectrometry.
Date:
December 10, 1999
Creator:
Amad, Ma'an Hazem
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Glass Waste Forms for Oak Ridge Tank Wastes: Fiscal Year 1998 Report for Task Plan SR-16WT-31, Task B
Using ORNL information on the characterization of the tank waste sludges, SRTC performed extensive bench-scale vitrification studies using simulants. Several glass systems were tested to ensure the optimum glass composition (based on the glass liquidus temperature, viscosity and durability) is determined. This optimum composition will balance waste loading, melt temperature, waste form performance and disposal requirements. By optimizing the glass composition, a cost savings can be realized during vitrification of the waste. The preferred glass formulation was selected from the bench-scale studies and recommended to ORNL for further testing with samples of actual OR waste tank sludges.
Date:
May 10, 1999
Creator:
Andrews, M.K.
Object Type:
Report
System:
The UNT Digital Library
Remote sensing of the atmosphere for environmental assessment and national security
The research performed this year marked the beginning of a collaboration between Howard University and LLNL to advance and apply remote sensing technology to a broad range of applications centered on probing the state of the atmosphere. Central to this research was the evolution of a telescope facility at Howard University into an atmospheric observatory and instrument development test-bed. Our work in applying laser technology to remote sensing helped lead to the development and subsequent patent application of a laser heterodyne amplifier and progress toward the development of a multi-wavelength laser probe to determine the range resolved size distribution of particulate matter and aerosols in the atmosphere. Work performed this year also helped us motivate further studies to understand atmospheric radiance and radiation transport in three-dimensions. Our involvement in these programs as supported by the LLNL Research Collaborations Program for Historically Black College s and Universities is reported here.
Date:
June 10, 1999
Creator:
Arens, J. F.; Davis, E.; Farah, A.; Molitoris, J. D. & Venable, D.
Object Type:
Report
System:
The UNT Digital Library
[2012.201.B0092.0509]
Photograph taken during daylight of a woman, child and dog in a Dog Ears exhibit tent. Caption: "Fred, a companion dog for the hearing-impaired, delivers a demonstration wake-up call to Peter Huang, 9, a third-grader at Northern Hill Elementary School in Edmond."
Date:
October 10, 1999
Creator:
Argo, Jim
Object Type:
Photograph
System:
The Gateway to Oklahoma History
The STAR Time Project Chamber
Paper presented at the International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (1999) reporting on the progress of the STAR experiment, a complex system of many detector sub-systems which have been installed in a large solenoidal magnet at the Relativistic Heavy Ion Collider (RHIC).
Date:
May 10, 1999
Creator:
Argonne National Laboratory
Object Type:
Article
System:
The UNT Digital Library
Isentropic Compression of Iron with the Z Accelerator
Development of isentropic loading techniques is a long standing goal of the shock physics community. The authors have used the Sandia Z Accelerator to produce smoothly increasing pressure loading on planar iron specimens over time durations of 100 ns and for pressures to 300 Mbar. Free surface velocity measurements on the rear surface of the continuously loaded specimens were made on specimens 0.5-mm and 0.8-mm thick and clearly show the effects of wave evolution into the well known two-wave structure resulting from the {alpha}-{var_epsilon} phase transition beginning at 125 kbar. The resulting wave profiles are analyzed with a rate-dependent, phase transition model to extract information on phase transformation kinetics for isentropic compression of iron. Comparison of the experiments and calculations demonstrate the value of isentropic loading for studying phase transition kinetics.
Date:
June 10, 1999
Creator:
Asay, J. R.; Bernard, M. A.; Hall, C. A.; Hayes, D. B.; Holland, K. G.; McDaniel, D. H. et al.
Object Type:
Article
System:
The UNT Digital Library
High-dielectric-constant ferroelectric thin film and bulk ceramic capacitors for power electronics.
Significant effort is presently focused on reducing the size and weight of power electronic modules. To achieve these goals in high-power capacitors, alternative materials and fabrication processes are needed. Thin film (<0.5 {micro}m) and bulk capacitors that use perovskite-based ferroelectric dielectrics are promising alternative technologies. Ferroelectrics possess high dielectric constants, thus offering substantial increases in volumetric capacitance. In thin film form, these materials display low loss and high breakdown strength. The unique properties of some of these materials, such as a nonlinear dielectric response or a high energy-storage capacity accompanying a phase change, can be exploited for power electronic capacitors. Prototype capacitors of two such materials, (Ba,Sr)TiO{sub 3} and PbZrO{sub 3}, have been fabricated in both thin film and bulk ceramic form. The influence of fabrication conditions on dielectric properties has been studied. Initial studies have demonstrated the viability of perovskite ferroelectrics for next-generation capacitor components.
Date:
August 10, 1999
Creator:
Auciello, O. H.; Baldo, P.; Baumann, P.; Erck, R. A.; Giumarra, J.; Im, J. et al.
Object Type:
Article
System:
The UNT Digital Library
In situ mass spectroscopy of recoiled ion studies of degradation processes in SrBi{sub 2}Ta{sub 2}O{sub 9} thin films during hydrogen gas annealing.
It is known that the forming gas (N{sub 2}-H{sub 2} mixture) annealing process required for microcircuit fabrication results in an unacceptable electrical degradation of SrBi{sub 2}Ta{sub 2}O{sub 9} (SBT) ferroelectric capacitors due mainly to the interaction of H{sub 2} with the ferroelectronic layer of the capacitor. We have found a strong relationship between changes in the surface composition of the ferroelectric layer and the electrical properties of SBT capacitors as a result of hydrogen annealing. Mass spectroscopy of recoiled ions (MSRI) analysis revealed a strong reduction in the Bi signal as a function of exposure to hydrogen at high temperatures ({approximately}500 C). The Bi signal reduction correlates with Bi depletion in the SBT surface region. Subsequent annealing in oxygen at temperatures in the range of 700-800 C resulted in the recovery of the MSRI Bi signal, corresponding to the replenishment of Bi in the previously Bi-depleted surface region. XRD analysis (probing the whole SBT film thickness) showed little difference in the XRD spectra of the SBT fti before and after hydrogen and oxygen-recovery annealing. The combined results of the MSRI and XRD analyses can be interpreted as an indication that the degradation of the electrical properties of the SBT capacitors, …
Date:
March 10, 1999
Creator:
Auciello, O.; Chang, R. P. H.; Gruen, D. M.; Im, J.; Kim, S. H.; Kingon, A. I. et al.
Object Type:
Article
System:
The UNT Digital Library
Finance and supply management project execution plan
As a subproject of the HANDI 2000 project, the Finance and Supply Management system is intended to serve FDH and Project Hanford major subcontractor with financial processes including general ledger, project costing, budgeting, and accounts payable, and supply management process including purchasing, inventory and contracts management. Currently these functions are performed with numerous legacy information systems and suboptimized processes.
Date:
February 10, 1999
Creator:
BENNION, S.I.
Object Type:
Report
System:
The UNT Digital Library
Software configuration management plan for HANDI 2000 business management system
The Software Configuration Management Plan (SCMP) describes the configuration management and control environment for HANDI 2000 for the PP and PS software, as well as any custom developed software. This plan establishes requirements and processes for uniform documentation and coordination of HANDI 2000. This SCMP becomes effective as of this document's acceptance and will provide guidance through implementation efforts.
Date:
February 10, 1999
Creator:
BENNION, S.I.
Object Type:
Report
System:
The UNT Digital Library