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Managing Performance Analysis with Dynamic Statistical Projection Pursuit

Description: Computer systems and applications are growing more complex. Consequently, performance analysis has become more difficult due to the complex, transient interrelationships among runtime components. To diagnose these types of performance issues, developers must use detailed instrumentation to capture a large number of performance metrics. Unfortunately, this instrumentation may actually influence the performance analysis, leading the developer to an ambiguous conclusion. In this paper, we introduce a technique for focusing a performance analysis on interesting performance metrics. This technique, called dynamic statistical projection pursuit, identifies interesting performance metrics that the monitoring system should capture across some number of processors. By reducing the number of performance metrics, projection pursuit can limit the impact of instrumentation on the performance of the target system and can reduce the volume of performance data.
Date: May 22, 2000
Creator: Vetter, J.S. & Reed, D.A.
Partner: UNT Libraries Government Documents Department

Kinetics of Beta-14[14C] Carotene in a Human Subject Using Accelerator Mass Spectrometry

Description: {beta}-Carotene is a tetraterpenoid distributed widely throughout the plant kingdom. It is a member of a group of pigments referred to as carotenoids that have the distinction of serving as metabolic precursors to vitamin A in humans and many animals [1,2]. We used Accelerator Mass Spectrometry (AMS) [3] to determine the metabolic behavior of a physiologic oral dose of {beta}-[{sup 14}C]carotene (200 nanoCuries; 0.57 {micro}mol) in a healthy human subject. Serial blood specimens were collected for 210-d and complete urine and feces were collected for 17 and 10-d, respectively. Balance data indicated that the dose was 42% bioavailable. The absorbed {beta}-carotene was lost slowly via urine in accord with the slow body turnover of {beta}-carotene and vitamin A [4]. HPLC fractionation of plasma taken at early time points (0-24-h) showed the label was distributed between {beta}-carotene and retinyl esters (vitamin A) derived from intestinal metabolism.
Date: January 31, 2000
Creator: Dueker, S.R.; Lin, Y.; Follett, J.R.; Clifford, A.J. & Buchholz, B.A.
Partner: UNT Libraries Government Documents Department

Lessons Learned and Present Day Challenges of Addressing 20th Century Radiation Legacies of Russia and the United States

Description: The decommissioning of nuclear submarines, disposal of highly-enriched uranium and weapons-grade plutonium, and processing of high-level radioactive wastes represent the most challenging issues facing the cleanup of 20th century radiation legacy wastes and facilities. The US and Russia are the two primary countries dealing with these challenges, because most of the world's fissile inventory is being processed and stored at multiple industrial sites and nuclear weapons production facilities in these countries.
Date: October 26, 2000
Partner: UNT Libraries Government Documents Department

Extreme Ultraviolet Lithography - Reflective Mask Technology

Description: EUVL mask blanks consist of a distributed Bragg reflector made of 6.7nm-pitch bi-layers of MO and Si deposited upon a precision Si or glass substrate. The layer deposition process has been optimized for low defects, by application of a vendor-supplied but highly modified ion-beam sputter deposition system. This system is fully automated using SMIF technology to obtain the lowest possible environmental- and handling-added defect levels. Originally designed to coat 150mm substrates, it was upgraded in July, 1999 to 200 mm and has coated runs of over 50 substrates at a time with median added defects >100nm below 0.05/cm{sup 2}. These improvements have resulted from a number of ion-beam sputter deposition system modifications, upgrades, and operational changes, which will be discussed. Success in defect reduction is highly dependent upon defect detection, characterization, and cross-platform positional registration. We have made significant progress in adapting and extending commercial tools to this purpose, and have identified the surface scanner detection limits for different defect classes, and the signatures of false counts and non-printable scattering anomalies on the mask blank. We will present key results and how they have helped reduce added defects. The physics of defect reduction and mitigation is being investigated by a program on multilayer growth over deliberately placed perturbations (defects) of varying size. This program includes modeling of multilayer growth and modeling of defect printability. We developed a technique for depositing uniformly sized gold spheres on EUVL substrates, and have studied the suppression of the perturbations during multilayer growth under varying conditions. This work is key to determining the lower limit of critical defect size for EUV Lithography. We present key aspects of this work. We will summarize progress in all aspects of EUVL mask blank development, and present detailed results on defect reduction and mask blank performance at EUV wavelengths.
Date: May 9, 2000
Creator: Walton, C.C.; Kearney, P.A.; Mirkarimi, P.B.; Bowers, J.M.; Cerjan, C.; Warrick, A.L. et al.
Partner: UNT Libraries Government Documents Department

Effect of Extrusion Temperature on the Microstructural Development of Powder Metallurgy Ti-47A1-2Cr-1Nb-1Ta Alloy

Description: Effect of extrusion temperatures on the microstructural development of a powder metallurgy (PM) Ti-47Al-2Cr-1Nb-1Ta (at. %) alloy has been investigated. Microstructure of the PM alloy extruded at 1150 C consists of a fine-grained ({gamma} + {alpha}{sub 2}) two-phase structure in association with coarse grains of metastable B2 (ordered bcc) phase. In addition, fine {omega} (ordered hexagonal) particles are also found within some B2 grains. The PM alloy containing the metastable B2 grains displays a low-temperature superplastic behavior, in which a tensile elongation of 310% is obtained at 800 C under a strain rate of 2 x 10{sup -5} s{sup -1}. It is suggested that the decomposition of metastable B2 phase and microstructural evolution during the deformation play a crucial role in the low-temperature superplasticity of the PM TiAl alloy. A refined fully-lamellar (FL) microstructure with alternating {gamma} and {alpha}{sub 2} lamellae is developed within the PM alloy extruded at 1400 C. The creep resistance of the refined FL-TiAl alloy is found to be superior to those of the TiAl alloys fabricated by conventional processing techniques. Creep mechanisms for the PM alloy with a refined FL microstructure are critically discussed according to TEM examination of deformation substructure.
Date: June 29, 2000
Creator: Hsiung, L. & Nieh, T.G.
Partner: UNT Libraries Government Documents Department

The Plutonium Transition from Nuclear Weapons to Crypt

Description: With the end of the ''Cold War'' thousands of nuclear warheads are being dismantled. The National Academy of Sciences termed this growing stockpile of plutonium and highly enriched uranium ''a clear and present danger'' to international security. DOE/MD selected a duel approach to plutonium disposition--burning MOX fuel in existing reactors and immobilization in a ceramic matrix surrounded by HLW glass. MOX material will be pits and clean metal. The challenges come with materials that will be transferred to Immobilization--these range from engineered materials to residues containing < 30% Pu. Impurity knowledge range from guesses to actual data. During packaging, sites will flag ''out of the ordinary'' containers for characterized. If the process history is lost, characterization cost will escalate rapidly. After two step blending and ceramic precursor addition, cold press and sintering will form 0.5-kg ceramic pucks containing {le}50 g Pu. Pucks will be sealed in cans, placed into magazines, then into HLW canisters; these canisters will be filled with HLW glass prior to being transported to the HLW repository. The Immobilization Program must interface with DP, EM, RW, and NN. Overlaid on top of these interfaces are the negotiations with the Russians.
Date: March 14, 2000
Creator: Gray, L.W.
Partner: UNT Libraries Government Documents Department

Waste In-Situ Stabilization/Entombment Research and Development Project

Description: The technical basis and stakeholder acceptance of entombment technology is necessary before entombment becomes a decontamination and decommissioning (D and D) option for nuclear reactors. The authors present a research and development (R and D) approach addressing technical basis and stakeholder acceptance of entombment technology. The approach includes a consortium and the conceptual R and D program.
Date: August 29, 2000
Creator: Vernon, D.K.; Birk, S.M. & Hanson, R.G.
Partner: UNT Libraries Government Documents Department

Analysis of Stress Waves Generated in Water Using Ultrashort Laser Pulses

Description: A Mach-Zehnder interferometer was used for analysis of pressure waves generated by ultrashort laser pulse ablation of water. It was found that the shock wave generated by plasma formation rapidly decays to an acoustic wave. Both experimental and theoretical studies demonstrated that the energy transfer to the mechanical shock was less than 1%.
Date: April 25, 2000
Creator: Kim, B.M.; Feit, M.D.; Rubenchik, A.M.; Komashko, A.M.; Reidt, S.; Eichler, J. et al.
Partner: UNT Libraries Government Documents Department

Technical Justification for Radiation Controls at an Environmental Laboratory

Description: This paper describes the technical approach used to establish radiation protection controls over incoming radioactive materials to an environmental measurements laboratory at the Hanford Site. Conditions that would trigger internal dosimetry, posting.
Date: July 1, 2000
Creator: DUPAQUIER, J.C.
Partner: UNT Libraries Government Documents Department

Target Design Activities for Inetrial Fusion Energy at Lawrence Livermore National Laboratory

Description: The authors studied a variety of targets to be driven by ion beams or lasers in the past year. In order to relax target fabrication requirements, expand the allowed beam phase space volume and meet some radiological safety requirements, they continued to extend the set of the distributed radiator target designs for heavy ion beams. The hydrodynamic stability of a high gain directly driven laser target recently proposed at the Naval Research Laboratory has been studied. Because target chambers are sensitive to the x-ray spectrum as well as the composition and energy of the capsule debris they also present these for this target. A novel implosion scheme for the Fast Ignitor fusion scenario that minimizes the amount of coronal plasma that the igniting laser beam must penetrate is described. They describe recently derived scaling laws that relate the minimum value of the incoming fuel kinetic energy to the peak drive pressure, the fuel adiabat and the implosion velocity for capsules that use the kinetic energy of the implosion to heat the hotspot to ignition temperatures.
Date: September 19, 2000
Creator: Tabal, M; Callahan-Miller, D.; Herrmann, M.; Hatchett, S.; Lindl, J. & Perkins, L.J.
Partner: UNT Libraries Government Documents Department

Imaging columns of the light elements carbon, nitrogen and oxygen with sub angstrom resolution

Description: It is reported that lattice imaging with a 300 kV field emission microscope in combination with numerical reconstruction procedures can be used to reach an interpretable resolution of about 80 pm for the first time. A retrieval of the electron exit wave from focal series allows for the resolution of single atomic columns of the light elements carbon, nitrogen, and oxygen at a projected nearest neighbor spacing down to 85 pm. Lens aberrations are corrected on-line during the experiment and by hardware such that resulting image distortions are below 80 pm. Consequently, the imaging can be aberration-free to this extent. The resolution enhancement results from increased electrical and mechanical stability's of the instrument coupled with a low spherical aberration coefficient of 0.595 + 0.005 mm.
Date: January 2, 2000
Creator: Kisielowski, C.; Hetherington, C.J.D.; Wang, Y.C.; Kilaas, R.; O'Keefe, M.A. & Thust, A.
Partner: UNT Libraries Government Documents Department

Effective File I/O Bandwidth Benchmark

Description: The effective I/O bandwidth benchmark (b{_}eff{_}io) covers two goals: (1) to achieve a characteristic average number for the I/O bandwidth achievable with parallel MPI-I/O applications, and (2) to get detailed information about several access patterns and buffer lengths. The benchmark examines ''first write'', ''rewrite'' and ''read'' access, strided (individual and shared pointers) and segmented collective patterns on one file per application and non-collective access to one file per process. The number of parallel accessing processes is also varied and well-formed I/O is compared with non-well formed. On systems, meeting the rule that the total memory can be written to disk in 10 minutes, the benchmark should not need more than 15 minutes for a first pass of all patterns. The benchmark is designed analogously to the effective bandwidth benchmark for message passing (b{_}eff) that characterizes the message passing capabilities of a system in a few minutes. First results of the b{_}eff{_}io benchmark are given for IBM SP and Cray T3E systems and compared with existing benchmarks based on parallel Posix-I/O.
Date: February 15, 2000
Creator: Rabenseifner, R. & Koniges, A.E.
Partner: UNT Libraries Government Documents Department

Building Scale Simulation in Support of Field Experiments around Salt Lake City

Description: Numerical modeling of the urban boundary layer is complicated by the need to describe airflow patterns outside of the computational domain. These patterns have an impact on how successfully the simulation is able to model the turbulence associated with the urban boundary layer. This talk presents experiments with the model boundary conditions for simulations that were done to support two Department of Energy observational programs involving the Salt Lake City basin. The Chemical/Biological Non-proliferation Program (CBNP) is concerned with the effects of buildings on influencing dispersion patterns in urban environments. The Vertical Transport and Mixing Program (VTMX) investigating mixing mechanisms in the stable boundary layer and how they are influenced by the channeling caused by drainage flows or by obstacles such as building complexes. Both of these programs are investigating the turbulent mixing caused by building complexes and other urban obstacles.
Date: May 30, 2000
Creator: Stevens, D.; Calhoun, R.J.; Chan, S.T.; Lee, R.L.; Leone, J. & Shinn, J.
Partner: UNT Libraries Government Documents Department

Wavelets on Planar Tesselations

Description: We present a new technique for progressive approximation and compression of polygonal objects in images. Our technique uses local parameterizations defined by meshes of convex polygons in the plane. We generalize a tensor product wavelet transform to polygonal domains to perform multiresolution analysis and compression of image regions. The advantage of our technique over conventional wavelet methods is that the domain is an arbitrary tessellation rather than, for example, a uniform rectilinear grid. We expect that this technique has many applications image compression, progressive transmission, radiosity, virtual reality, and image morphing.
Date: February 25, 2000
Creator: Bertram, M.; Duchaineau, M.A.; Hamann, B. & Joy, K.I.
Partner: UNT Libraries Government Documents Department