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438 Matching Results
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How Root Cause Analysis Can Improve the Value Methodology
Root cause analysis (RCA) is an important methodology that can be integrated with the VE Job Plan to generate superior results from the VE Methodology. The point at which RCA is most appropriate is after the function analysis and FAST Model have been built and functions for improvement have been chosen. These functions are then subjected to a simple, but, rigorous RCA to get to the root cause of their deficiencies, whether it is high cost/poor value, poor quality, or poor reliability. Once the most probable causes for these problems have been arrived at, better solutions for improvement can be developed in the creativity phase because the team better understands the problems associated with these functions.
Date:
February 5, 2002
Creator:
Wixson, J. R.
Object Type:
Article
System:
The UNT Digital Library
Chamber wall response to target implosion in inertial fusion reactors : new and critical assessments.
The chamber walls in inertial fusion energy (IFE) reactors are exposed to harsh conditions following each target implosion. Key issues of the cyclic IFE operation include intense photon and ion deposition, wall thermal and hydrodynamic evolution, wall erosion and fatigue lifetime, and chamber clearing and evacuation to ensure desirable conditions prior to target implosion. Several methods for wall protection have been proposed in the past, each having its own advantages and disadvantages. These methods include use of solid bare walls, gas-filled cavities, and liquid walls/jets. Detailed models have been developed for reflected laser light, emitted photons, and target debris deposition and interaction with chamber components and have been implemented in the comprehensive HEIGHTS software package. The hydrodynamic response of gas filled cavities and photon radiation transport of the deposited energy has been calculated by means of new and advanced numerical techniques. Fragmentation models of liquid jets as a result of the deposited energy have also been developed, and the impact on chamber clearing dynamics has been evaluated. The focus of this study is to critically assess the reliability and the dynamic response of chamber walls in various proposed protection methods for IFE systems. Of particular concern is the effect on …
Date:
August 5, 2002
Creator:
Hassanein, A. & Morozov, V.
Object Type:
Article
System:
The UNT Digital Library
Flavor structure of the nucleon as revealed at HERMES.
The flavor structure of the nucleon as revealed in parton distributions (PDF's) is central to understanding the partonic structure of the nucleon. Recent data on unpolarized PDF's and their implications for the flavor-dependent quark helicity distributions are discussed. Results are presented for spin asymmetries in inclusive and semi-inclusive cross sections for production of pions, and kaons measured by the HERMES experiment in deep-inelastic scattering of polarized positrons on proton and deuterium Targets. A full 5 component extraction of polarized quark distributions for u, d, {bar u}, {bar d}, and (s + {bar s}) is reported. Resulting valence quark distributions conform to results of earlier experiments. There is no evidence for a significant polarization of the light sea. In contrast to the conclusions inferred from studies of polarized inclusive scattering, a leading order analysis of the HERMES data suggests a zero or slightly positive polarization of the strange sea. There is no evidence for a measurable flavor asymmetry in the polarized distributions for the light sea.
Date:
September 5, 2002
Creator:
Jackson, H. E.
Object Type:
Article
System:
The UNT Digital Library
Snowmass 2001: Jet energy flow project
Conventional cone jet algorithms arose from heuristic considerations of LO hard scattering coupled to independent showering. These algorithms implicitly assume that the final states of individual events can be mapped onto a unique set of jets that are in turn associated with a unique set of underlying hard scattering partons. Thus each final state hadron is assigned to a unique underlying parton. The Jet Energy Flow (JEF) analysis described here does not make such assumptions. The final states of individual events are instead described in terms of flow distributions of hadronic energy. Quantities of physical interest are constructed from the energy flow distribution summed over all events. The resulting analysis is less sensitive to higher order perturbative corrections and the impact of showering and hadronization than the standard cone algorithms.
Date:
December 5, 2002
Creator:
al., C. F. Berger et
Object Type:
Article
System:
The UNT Digital Library
Raman forward scattering of chirped laser pulses
Raman scattering of a high-intensity, short duration, frequency-chirped laser pulse propagating in an underdense plasma is examined. The growth of the direct forward scattered light is calculated for a laser pulse with a linear frequency chirp in various spatio-temporal regimes. This includes a previously undescribed regime of strongly-coupled four-wave nonresonant interaction, which is important for relativistic laser intensities. In all regimes of forward scattering, it is shown that the growth rate increases (decreases) for positive (negative) frequency chirp. The effect of chirp on the growth rate is relatively minor, i.e., a few percent chirp yields few percent changes in the growth rates. Numerical solutions based on fully nonlinear cold Maxwell-fluid model are presented which confirm analytical predictions. Relation of these results to recent experiments is discussed.
Date:
December 5, 2002
Creator:
Schroeder, C. B.; Esarey, E.; Shadwick, B. A. & Leemans, W. P.
Object Type:
Article
System:
The UNT Digital Library
Aberration correction for analytical in situ TEM - the NTEAM concept.
Future aberration corrected transmission electron microscopes (TEM) will have a strong impact in materials science, since such microscopes yield information on chemical bonding and structure of interfaces, grain boundaries and lattice defects at an atomic level. Beyond this aberration correction offers new possibilities for in situ experiments performed under controlled temperature, magnetic field, strain etc. at atomic resolution. Such investigations are necessary for solving problems arising from electronic component miniaturization, for example. Significant progress can be expected by means of analytical aberration corrected TEM. These next generation microscopes will be equipped with an aberration corrected imaging system, a monochromator and aberration corrected energy filters. These novel elements have already been designed and partially realized [1,2,3].
Date:
March 5, 2002
Creator:
Kabius, B.; Allen, C. W. & Miller, D. J.
Object Type:
Article
System:
The UNT Digital Library
Final Report for CoDeveloper: A Secure, Web-invocable Collaborative Software Development Tool
We implemented a secure prototype for collaborative tool for code development.
Date:
April 5, 2002
Creator:
Shasharina, Dr. Svetlana
Object Type:
Report
System:
The UNT Digital Library
Final report, DOE Grant DE-FG02-98ER25352, Computational semidefinite programming
Semidefinite programming (SDP) is an extension of linear programming, with vector variables replaced by matrix variables and component wise nonnegativity replaced by positive semidefiniteness. SDP's are convex, but not polyhedral, optimization problems. SDP is well on its way to becoming an established paradigm in optimization, with many current potential applications. Consequently, efficient methods and software for solving SDP's are of great importance. During the award period, attention was primarily focused on three aspects of computational semidefinite programming: General-purpose methods for semidefinite and quadratic cone programming; Specific applications (LMI problems arising in control, minimizing a sum of Euclidean norms, a quantum mechanics application of SDP); and Optimizing matrix stability.
Date:
September 5, 2002
Creator:
Overton, Michael L.
Object Type:
Report
System:
The UNT Digital Library
A generic approach to improved semi-solid forming of metals
Lack of technology for the production of large inexpensive feedstock, with uniform spherical primary phase throughout as required for semi-solid forming, has restricted realization of the full potential for the semi-solid forming process. Furthermore, narrow process windows and alloy chemistry restrictions increase process costs and limit performance attributes possible with existing semi-solid metal systems. Successful semi-solid forming trials utilizing Chesapeake Composites Corporation's DSC trademark Metals for feedstock indicate that this represents a generic approach to providing a permanent highly uniform, spherical solid phase, without electromagnetic or mechanical shearing. This approach also provides for further growth of semi-solid forming by providing for: low cost large diameter billet stock, reduced semi-solid forming costs, extension of semi-solid forming to new alloy systems, and semi-solid formed components with substantially enhanced physical and mechanical proper ties.
Date:
June 5, 2002
Creator:
Klier, E. M.
Object Type:
Report
System:
The UNT Digital Library
AN OPTIMIZED DESIGN FOR THE NSLS 53 MHZ RF CAVITIES AND THE ANCILLARY COMPONENTS.
RF cavities are among the most complex components of a particle accelerator. They perform optimally when all electrical, mechanical and vacuum requirements are fully integrated. This paper focuses on the mechanical design features of the new 53MHz room-temperature RF cavities (including their ancillary components) for the X-ray Ring at the National Synchrotron Light Source (NSLS). Differences between the new and previous designs of the RF cavities, input couplers, Higher-Order-Mode (HOM) dampers, and cooling and vacuum systems are reviewed. Thus far, two out of four units have already been constructed, tested, and installed into the X-Ray ring, and two additional RF cavities are planned. The features incorporated into the new all-copper RF cavities have already demonstrated superior performance over the original copper-plated steel design. The operating performance results along with some of manufacturing challenges are presented.
Date:
September 5, 2002
Creator:
MORTAZAVI,P.
Object Type:
Article
System:
The UNT Digital Library
A new Energy Saving method of manufacturing ceramic products from waste glass
This final report summarizes the activities of the DOE Inventions and Innovations sponsored project, ''A New Energy Saving Method of Manufacturing Ceramic Products from Waste Glass.'' The project involved an innovative method of lowering energy costs of manufacturing ceramic products by substituting traditional raw materials with waste glass. The processing method is based on sintering of glass powder at {approx}750 C to produce products which traditionally require firing temperatures of >1200 C, or glass-melting temperatures >1500 C. The key to the new method is the elimination of previous processing problems, which have greatly limited the use of recycled glass as a ceramic raw material. The technology is aligned with the DOE-OIT Glass Industry Vision and Roadmap, and offers significant energy savings and environmental benefits compared to current technologies. A U.S. patent (No. 6,340,650) covering the technology was issued on January 22, 2002. An international PCT Patent Application is pending with designations made for all PCT regions and countries. The goal of the project was to provide the basis for the design and construction of an energy-efficient manufacturing plant that can convert large volumes of waste glass into high-quality ceramic tile. The main objectives of the project were to complete process …
Date:
July 5, 2002
Creator:
Labs, Haun
Object Type:
Report
System:
The UNT Digital Library
MECHANICAL DESIGN OF NSLS MINI - GAP UNDULATOR (MGU)
The mechanical design considerations are discussed with respect to the currently installed X-13 and future X-29 MGU. Comparisons to the previous 2 generations of variable small-gap undulator evolution in the NSLS X-ray ring are made and design improvements noted. The design requirements and mechanical difficulties for holding, positioning and driving the magnetic arrays are explored. Structural, thermal and electrical considerations which influenced the design are then analyzed. The mechanical performance of the MGU currently installed at X-13 is examined and future installations and enhancements are presented.
Date:
September 5, 2002
Creator:
Lynch, D. & Rakowsky, G.
Object Type:
Article
System:
The UNT Digital Library
Size Scaling of Turbulent Transport in Magnetically Confined Plasmas
Transport scaling with respect to device size in magnetically confined plasmas is critically examined for electrostatic ion temperature gradient turbulence using global gyrokinetic particle simulations. It is found, by varying device size normalized by ion gyroradius while keeping other dimensionless plasma parameters fixed, that fluctuation scale length is microscopic in the presence of zonal flows. The local transport coefficient exhibits a gradual transition from a Bohm-like scaling for device sizes corresponding to present-day experiments to a gyro-Bohm scaling for future larger devices.
Date:
April 5, 2002
Creator:
Lin, Z.; Ethier, S.; Hahm, T.S. & Tang, W.M.
Object Type:
Report
System:
The UNT Digital Library
Development of High Waste Loading Glasses for Advanced Melter Technologies
The vitrification programs at Hanford and Savannah River may benefit from higher temperature glass formulations that are processable in advanced melters (e.g., induction-heated, cold-crucible melter (ICCM)) or by changing the current liquidus temperature (TL) limit for Joule heated ceramic melters (JHCM). The focus of this report was on the glass formulation activities in support of the ICCM and JHCM demonstrations with C-106/AY-102 simulant. The intent was to provide preliminary (non-optimized) glass formulations for a specific waste stream that met processing requirements, DOE product quality specifications, and programmatic objectives for the two melter types.
Date:
December 5, 2002
Creator:
Peeler, D.K.
Object Type:
Report
System:
The UNT Digital Library
Evaluation of Possible Nuclear Magnetic Resonance Diagnostic Techniques for Tokamak Experiments
Potential applications of nuclear magnetic resonance (NMR) diagnostic techniques to tokamak experiments are evaluated. NMR frequencies for hydrogen isotopes and low-Z nuclei in such experiments are in the frequency range approximately equal to 20-200 MHz, so existing RF [radio-frequency] antennas could be used to rotate the spin polarization and to make the NMR measurements. Our tentative conclusion is that such measurements are possible if highly spin polarized H or (superscript)3He gas sources (which exist) are used to fuel these plasmas. In addition, NMR measurements of the surface layers of the first wall (without plasma) may also be possible, e.g., to evaluate the inventory of tritium inside the vessel.
Date:
August 5, 2002
Creator:
Zweben, S. J.; Kornack, T. W.; Majeski, D.; Schilling, G.; Skinner, C. H. & Wilson, R.
Object Type:
Report
System:
The UNT Digital Library
Diffractive optical elements based on Fourier optical techniques: A new class of optics for extreme ultraviolet and soft x-ray wavelengths
None
Date:
May 5, 2002
Creator:
Chang, Chang; Naulleau, Patrick; Anderson, Erik; Rosfjord, Kristine & Attwood, David
Object Type:
Article
System:
The UNT Digital Library
Report of the Snowmass T7 working group on high performance computing
The T7 Working Group on High Performance Computing (HPC) had more than 30 participants. During the three weeks at Snowmass there were about 30 presentations. This working group also had joint sessions with a number of other working groups, including E1 (Neutrino Factories and Muon Colliders), M1 (Muon Based Systems), M6 (High Intensity Proton Sources), T4 (Particle sources), T5 (Beam dynamics), and T8 (Advanced Accelerators). The topics that were discussed fall naturally into three areas: (1) HPC requirements for next-generation accelerator design, (2) state-of-the-art in HPC simulation of accelerator systems, and (3) applied mathematics and computer science activities related to the development of HPC tools that will be of use to the accelerator community (as well as other communities). This document summarizes the material mentioned above and includes recommendations for future HPC activities in the accelerator community. The relationship of those activities to the HENP/SciDAC project on 21st century accelerator simulation is also discussed.
Date:
December 5, 2002
Creator:
Ko, K.; Ryne, R. & Spentzouris, P.
Object Type:
Article
System:
The UNT Digital Library
Post Waterflood CO2 Miscible Flood in Light Oil, Fluvial-Dominated Deltaic Reservoir (Pre-Work and Project Proposal - Appendix)
The main objective of the Port Neches Project was to determine the feasibility and producibility of CO2 miscible flooding techniques enhanced with horizontal drilling applied to a Fluvial Dominated Deltaic reservoir. The second was to disseminate the knowledge gained through established Technology Transfer mechanisms to support DOE's programmatic objectives of increasing domestic oil production and reducing abandonment of oil fields.
Date:
February 5, 2002
Creator:
Bou-Mikael, Sami
Object Type:
Report
System:
The UNT Digital Library
Assessment of Nonnative Invasive Plants in the DOE Oak Ridge National Environmental Research Park
The Department of Energy (DOE) National Environmental Research Park at Oak Ridge, Tennessee, is composed of second-growth forest stands characteristic of much of the eastern deciduous forest of the Ridge and Valley Province of Tennessee. Human use of natural ecosystems in this region has facilitated the establishment of at least 167 nonnative, invasive plant species on the Research Park. Our objective was to assess the distribution, abundance, impact, and potential for control of the 18 most abundant invasive species on the Research Park. In 2000, field surveys were conducted of 16 management areas on the Research Park (14 Natural Areas, 1 Reference Area, and Walker Branch Watershed) and the Research Park as a whole to acquire qualitative and quantitative data on the distribution and abundance of these taxa. Data from the surveys were used to rank the relative importance of these species using the ''Alien Plant Ranking System, Version 5.1'' developed by the U.S. Geological Survey. Microstegium (Microstegium vimineum) was ranked highest, or most problematic, for the entire Research Park because of its potential impact on natural systems, its tendency to become a management problem, and how difficult it is to control. Microstegium was present in 12 of the 16 …
Date:
November 5, 2002
Creator:
Drake, S. J.
Object Type:
Report
System:
The UNT Digital Library
Ventilation Model
The purpose of the Ventilation Model is to simulate the heat transfer processes in and around waste emplacement drifts during periods of forced ventilation. The model evaluates the effects of emplacement drift ventilation on the thermal conditions in the emplacement drifts and surrounding rock mass, and calculates the heat removal by ventilation as a measure of the viability of ventilation to delay the onset of peak repository temperature and reduce its magnitude. The heat removal by ventilation is temporally and spatially dependent, and is expressed as the fraction of heat carried away by the ventilation air compared to the fraction of heat produced by radionuclide decay. One minus the heat removal is called the wall heat fraction, or the remaining amount of heat that is transferred via conduction to the surrounding rock mass. Downstream models, such as the ''Multiscale Thermohydrologic Model'' (BSC 2001), use the wall heat fractions as outputted from the Ventilation Model to initialize their post-closure analyses. The Ventilation Model report was initially developed to analyze the effects of preclosure continuous ventilation in the Engineered Barrier System (EBS) emplacement drifts, and to provide heat removal data to support EBS design. Revision 00 of the Ventilation Model included documentation …
Date:
October 5, 2002
Creator:
Chipman, V.
Object Type:
Report
System:
The UNT Digital Library
NATURAL GAS RESOURCES IN DEEP SEDIMENTARY BASINS
From a geological perspective, deep natural gas resources are generally defined as resources occurring in reservoirs at or below 15,000 feet, whereas ultra-deep gas occurs below 25,000 feet. From an operational point of view, ''deep'' is often thought of in a relative sense based on the geologic and engineering knowledge of gas (and oil) resources in a particular area. Deep gas can be found in either conventionally-trapped or unconventional basin-center accumulations that are essentially large single fields having spatial dimensions often exceeding those of conventional fields. Exploration for deep conventional and unconventional basin-center natural gas resources deserves special attention because these resources are widespread and occur in diverse geologic environments. In 1995, the U.S. Geological Survey estimated that 939 TCF of technically recoverable natural gas remained to be discovered or was part of reserve appreciation from known fields in the onshore areas and State waters of the United. Of this USGS resource, nearly 114 trillion cubic feet (Tcf) of technically-recoverable gas remains to be discovered from deep sedimentary basins. Worldwide estimates of deep gas are also high. The U.S. Geological Survey World Petroleum Assessment 2000 Project recently estimated a world mean undiscovered conventional gas resource outside the U.S. of 844 …
Date:
February 5, 2002
Creator:
Dyman, Thaddeus S.; Cook, Troy; Crovelli, Robert A.; Henry, Allison A.; Hester, Timothy C.; Johnson, Ronald C. et al.
Object Type:
Report
System:
The UNT Digital Library
Midwest Transmission Workshop II Summary
OAK-B135 After introductions of all participants, Abby Arnold, RESOLVE, reviewed the purpose of the meeting and the agenda. The purpose of the workshop was to share the results of the Midwest Independent System Operator (MISO) scenario development for wind and other fuel sources and the corresponding implications for transmission throughout the MISO control area. The workshop agenda is included in Attachment A.
Date:
December 5, 2002
Creator:
Bryan, Kevin
Object Type:
Report
System:
The UNT Digital Library
Controlling the morphology of nanocrystal-polymer composites for solar cells
None
Date:
June 5, 2002
Creator:
Huynh, Wendy U.; Dittmer, Janke J.; Libby, William C.; Whiting, Gregory L. & Alivisatos, A. Paul
Object Type:
Article
System:
The UNT Digital Library
The Effects of Processing Parameters on Microstructure and Properties of Laser Deposited PM Alloy 690N{sub 2} Powder
Powder Metallurgy (PM) Alloy 690N{sub 2}, the PM derivative of Inconel 690 (IN 690), has been shown to have a higher elevated temperature yield strength and superior stress corrosion cracking (SCC) resistance than conventionally processed IN 690. The property improvements seen in Alloy PM 690N{sub 2} are due to interstitial nitrogen strengthening and precipitation hardening resulting from the formation of fine Titanium/Chromium-nitrides. The application of Alloy PM 690N{sub 2} has had limited use due to the high costs involved in producing wrought products from powder. Laser Powder Deposition (LPD) offers another technique to take advantage of PM 690N{sub 2} properties. Three different variations of the Alloy 690 chemistry have been deposited, PM chemistry-nitrogen atomized (PM 690N{sub 2}), Ingot Metallurgy (IM) chemistry--nitrogen atomized (IM 690N{sub 2}), and IM chemistry--argon atomized (IM 690Ar). The microstructural and mechanical property variations of these LPD deposited materials are reported. Alloy PM 690N{sub 2} powder was laser deposited at rates from .1 to over 12 cubic inches per hour at laser input powers ranging from 250 to 5000 watts using both CO{sub 2} and Nd:YAG lasers. in all cases a fully dense material has been produced. There is a question however of how the properties of …
Date:
April 5, 2002
Creator:
Sears, J.W.
Object Type:
Report
System:
The UNT Digital Library