States

Evaluation of the Cask Transportation Facility Modifications (CTFM) compliance to DOE order 6430.1A Project A.5 and A.6 (open access)

Evaluation of the Cask Transportation Facility Modifications (CTFM) compliance to DOE order 6430.1A Project A.5 and A.6

This report was prepared to evaluate the compliance of CTFM to DOE Order 6430.1A. This document presents the results of an evaluation that was performed to assess compliance of the K West (KW) Cask Transportation Facility Modifications (CTFM) designs against applicable requirements of Department of Energy (DOE) Order 6430.1 A, General Design Criteria. This evaluation was grouped under two categories described as Cask Loadout System (CLS) and Cranes/Other Modifications.
Date: April 24, 2000
Creator: ARD, K.E.
Object Type: Report
System: The UNT Digital Library
Micro-Grooving and Micro-Threading Tools for Fabricating Curvilinear Features (open access)

Micro-Grooving and Micro-Threading Tools for Fabricating Curvilinear Features

This paper presents techniques for fabricating microscopic, curvilinear features in a variety of workpiece materials. Micro-grooving and micro-threading tools having cutting widths as small as 13 {micro}m are made by focused ion beam sputtering and used for ultra-precision machining. Tool fabrication involves directing a 20 keV gallium beam at polished cylindrical punches made of cobalt M42 high-speed steel or C2 tungsten carbide to create a number of critically aligned facets. Sputtering produces rake facets of desired angle and cutting edges having radii of curvature equal to 0.4 {micro}m. Clearance for minimizing frictional drag of a tool results from a particular ion beam/target geometry that accounts for the sputter yield dependence on incidence angle. It is believed that geometrically specific cutting tools of this dimension have not been made previously. Numerically controlled, ultra-precision machining with micro-grooving tools results in a close match between tool width and feature size. Microtools are used to machine 13 {micro}m wide, 4 {micro}m deep, helical grooves in polymethyl methacrylate and 6061 Al cylindrical workplaces. Micro-grooving tools are also used to fabricate sinusoidal cross-section features in planar metal samples.
Date: July 24, 2000
Creator: Adams, David P.; Vasile, Michael J. & Krishnan, A. S. M.
Object Type: Article
System: The UNT Digital Library
Top quark physics (open access)

Top quark physics

The top quark, when it was finally discovered at Fermilab in 1995 completed the three-generation structure of the Standard Model (SM) and opened up the new field of top quark physics. Viewed as just another SM quark, the top quark appears to be a rather uninteresting species. Produced predominantly, in hadron-hadron collisions, through strong interactions, it decays rapidly without forming hadrons, and almost exclusively through the single mode t {r_arrow} Wb. The relevant CKM coupling V{sub tb} is already determined by the (three-generation) unitarity of the CKM matrix. Rare decays and CP violation are unmeasurable small in the SM. Yet the top quark is distinguished by its large mass, about 35 times larger than the mass of the next heavy quark, and intriguingly close to the scale of electroweak (EW) symmetry breaking. This unique property raises a number of interesting questions. Is the top quark mass generated by the Higgs mechanism as the SM predicts and is its mass related to the top-Higgs-Yukawa coupling? Or does it play an even more fundamental role in the EW symmetry breaking mechanism? If there are new particles lighter than the top quark, does the top quark decay into them? Could non-SM physics first …
Date: March 24, 2000
Creator: Ahmadov, A.; Azuelos, G.; Bauer, U.; Belyaev, A.; Berger, E. L.; Sullivan, Z. et al.
Object Type: Article
System: The UNT Digital Library
CO-FIRING COAL: FEEDLOT AND LITTER BIOMASS FUELS (open access)

CO-FIRING COAL: FEEDLOT AND LITTER BIOMASS FUELS

The following are proposed activities for quarter 1 (6/15/00-9/14/00): (1) Finalize the allocation of funds within TAMU to co-principal investigators and the final task lists; (2) Acquire 3 D computer code for coal combustion and modify for cofiring Coal:Feedlot biomass and Coal:Litter biomass fuels; (3) Develop a simple one dimensional model for fixed bed gasifier cofired with coal:biomass fuels; and (4) Prepare the boiler burner for reburn tests with feedlot biomass fuels. The following were achieved During Quarter 5 (6/15/00-9/14/00): (1) Funds are being allocated to co-principal investigators; task list from Prof. Mukhtar has been received (Appendix A); (2) Order has been placed to acquire Pulverized Coal gasification and Combustion 3 D (PCGC-3) computer code for coal combustion and modify for cofiring Coal: Feedlot biomass and Coal: Litter biomass fuels. Reason for selecting this code is the availability of source code for modification to include biomass fuels; (3) A simplified one-dimensional model has been developed; however convergence had not yet been achieved; and (4) The length of the boiler burner has been increased to increase the residence time. A premixed propane burner has been installed to simulate coal combustion gases. First coal, as a reburn fuel will be used to …
Date: October 24, 2000
Creator: Annamalai, Dr. Kalyan; Sweeten, Dr. John & Mukhtar, Dr. Sayeed
Object Type: Report
System: The UNT Digital Library
Recent Advances in High-Pressure Equation-of-State Capabilities (open access)

Recent Advances in High-Pressure Equation-of-State Capabilities

For many scientific and programmatic applications, it is necessary to determine the shock compression response of materials to several tens of Mbar. In addition, a complete EOS is often needed in these applications, which requires that shock data be supplemented with other information, such as temperature measurements or by EOS data off the principal Hugoniot. Recent developments in the use of fast pulsed power techniques for EOS studies have been useful in achieving these goals. In particular, the Z accelerator at Sandia National Laboratories, which develops over 20 million amperes of current in 100-200 ns, can be used to produce muM-Mbar shock pressures and to obtain continuous compression data to pressures exceeding 1 Mbar. With this technique, isentropic compression data have been obtained on several materials to pressures of several hundred kbar. The technique has also been used to launch ultra-high velocity flyer plates to a maximum velocity of 14 km/s, which can be used to produce impact pressures of several Mbar in low impedance materials and over 10 Mbar in high impedance materials. The paper will review developments in both of these areas.
Date: July 24, 2000
Creator: Asay, James R.; Hall, Clint A. & Knudson, Marcus D.
Object Type: Article
System: The UNT Digital Library
Nonlinear self-duality in even dimensions (open access)

Nonlinear self-duality in even dimensions

We show that the Born-Infeld theory with n complex abelian gauge fields written in an auxiliary field formulation has a U(n, n) duality group. We conjecture the form of the Lagrangian obtained by eliminating the auxiliary fields and then introduce a new reality structure leading to a Born-Infeld theory with n real gauge fields and an Sp(2n, IR) duality symmetry. The real and complex constructions are extended to arbitrary even dimensions. The maximal noncompact duality group is U(n, n) for complex fields. For real fields the duality group is Sp(2n, IR) if half of the dimension of space-time is even and O(n, n) if it is odd. We also discuss duality under the maximal compact subgroup, which is the self-duality group of the theory obtained by fixing the expectation value of a scalar field. Supersymmetric versions of self-dual theories in four dimensions are also discussed.
Date: March 24, 2000
Creator: Aschieri, Paolo; Brace, Daniel; Morariu, Bogdan & Zumino, Bruno
Object Type: Article
System: The UNT Digital Library
Cantilever Epitaxy: A simple Lateral Growth Technique for Reducing Dislocation Densitites in GaN and Other Nitrides (open access)

Cantilever Epitaxy: A simple Lateral Growth Technique for Reducing Dislocation Densitites in GaN and Other Nitrides

None
Date: October 24, 2000
Creator: Ashby, Carol I.; Willan, Christine C.; Han, Jung; Missert, Nancy A.; Provencio, Paula P.; Follstaedt, David M. et al.
Object Type: Article
System: The UNT Digital Library
Enabling Computational Technologies for Terascale Scientific Simulations (open access)

Enabling Computational Technologies for Terascale Scientific Simulations

We develop scalable algorithms and object-oriented code frameworks for terascale scientific simulations on massively parallel processors (MPPs). Our research in multigrid-based linear solvers and adaptive mesh refinement enables Laboratory programs to use MPPs to explore important physical phenomena. For example, our research aids stockpile stewardship by making practical detailed 3D simulations of radiation transport. The need to solve large linear systems arises in many applications, including radiation transport, structural dynamics, combustion, and flow in porous media. These systems result from discretizations of partial differential equations on computational meshes. Our first research objective is to develop multigrid preconditioned iterative methods for such problems and to demonstrate their scalability on MPPs. Scalability describes how total computational work grows with problem size; it measures how effectively additional resources can help solve increasingly larger problems. Many factors contribute to scalability: computer architecture, parallel implementation, and choice of algorithm. Scalable algorithms have been shown to decrease simulation times by several orders of magnitude.
Date: August 24, 2000
Creator: Ashby, S.F.
Object Type: Report
System: The UNT Digital Library
Condition Monitoring of a Thermally Aged HTPB/IPDI Elastomer by NMR CP Recovery Times (open access)

Condition Monitoring of a Thermally Aged HTPB/IPDI Elastomer by NMR CP Recovery Times

A hydroxy-terminated polybutadiene (HTPB)/isophorone diisocyanate (IPDI) elastomer is commonly used as propellant binder material. The thermal degradation of the binder is believed to be an important parameter governing the performance of the propellant. The aging of these binders can be monitored by mechanical property measurements such as modulus or tensile elongation. These techniques, however, are not easily adapted to binder agents that are dispersed throughout a propellant. In this paper the authors investigated solid state NMR relaxation times as a means to predict the mechanical properties of the binder as a function of aging time. {sup 1}H spin-lattice and spin-spin relaxation times were found to be insensitive to the degree of thermal degradation of the elastomer. Apparently these relaxation times depend on localized motions that are only weakly correlated with mechanical properties. A strong correlation was found between the {sup 13}C cross-polarization (CP) NMR time constant, T{sub cp}, and the tensile elongation at break of the elastomer as a function of aging time. A ramped-amplitude CP experiment was shown to be less sensitive to imperfections in setting critical instrumental parameters for this mobile material.
Date: July 24, 2000
Creator: Assink, Roger A.; Lang, David & Celina, Mathias C.
Object Type: Article
System: The UNT Digital Library
Atmospheric Radiation Measurement Program Facilities Newsletter, February 2000 (open access)

Atmospheric Radiation Measurement Program Facilities Newsletter, February 2000

Monthly newsletter discussing news and activities related to the Atmospheric Radiation Measurement Program, articles about weather and atmospheric phenomena, and other related topics.
Date: March 24, 2000
Creator: Atmospheric Radiation Measurement Program (U.S.)
Object Type: Journal/Magazine/Newsletter
System: The UNT Digital Library
Science and technology of ultrananocrystalline diamond (UNCD) thin films for multifunctional devices (open access)

Science and technology of ultrananocrystalline diamond (UNCD) thin films for multifunctional devices

MEMS devices are currently fabricated primarily in silicon because of the available surface machining technology. However, Si has poor mechanical and tribological properties, and practical MEMS devices are currently limited primarily to applications involving only bending and flexural motion, such as cantilever accelerometers and vibration sensors. However, because of the poor flexural strength and fracture toughness of Si, and the tendency of Si to adhere to hydrophyllic surfaces, even these simple devices have limited dynamic range. Future MEMS applications that involve significant rolling or sliding contact will require the use of new materials with significantly improved mechanical and tribological properties, and the ability to perform well in harsh environments. Diamond is a superhard material of high mechanical strength, exceptional chemical inertness, and outstanding thermal stability. The brittle fracture strength is 23 times that of Si, and the projected wear life of diamond MEMS moving mechanical assemblies (MEMS-MMAs) is 10,000 times greater than that of Si MMAs. However, as the hardest known material, diamond is notoriously difficult to fabricate. Conventional CVD thin film deposition methods offer an approach to the fabrication of ultra-small diamond structures, but the films have large grain size, high internal stress, poor intergranular adhesion, and very rough …
Date: August 24, 2000
Creator: Auciello, O.; Krauss, A. R.; Gruen, D. M.; Jayatissa, A.; Sumant, A.; Tucek, J. et al.
Object Type: Article
System: The UNT Digital Library
Torsional Ratcheting Actuating System (open access)

Torsional Ratcheting Actuating System

A new type of surface micromachined ratcheting actuation system has been developed at the Microelectronics Development Laboratory at Sandia National Laboratories. The actuator uses a torsional electrostatic comb drive that is coupled to an external ring gear through a ratcheting scheme. The actuator can be operated with a single square wave, has minimal rubbing surfaces, maximizes comb finger density, and can be used for open-loop position control. The prototypes function as intended with a minimum demonstrated operating voltage of 18V. The equations of motion are developed for the torsional electrostatic comb drive. The resonant frequency, voltage vs. displacement and force delivery characteristics are predicted and compared with the fabricated device's performance.
Date: January 24, 2000
Creator: BARNES,STEPHEN MATTHEW; MILLER,SAMUEL L.; RODGERS,M. STEVEN & BITSIE,FERNANDO
Object Type: Article
System: The UNT Digital Library
Requirements Analysis Study for Master Pump Shutdown System Project Development Specification [SEC 1 and 2] (open access)

Requirements Analysis Study for Master Pump Shutdown System Project Development Specification [SEC 1 and 2]

This document has been updated during the definitive design portion of the first phase of the W-314 Project to capture additional software requirements and is planned to be updated during the second phase of the W-314 Project to cover the second phase of the Project's scope. The objective is to provide requirement traceability by recording the analysis/basis for the functional descriptions of the master pump shutdown system. This document identifies the sources of the requirements and/or how these were derived. Each requirement is validated either by quoting the source or an analysis process involving the required functionality, performance characteristics, operations input or engineering judgment.
Date: March 24, 2000
Creator: BEVINS, R.R.
Object Type: Report
System: The UNT Digital Library
On the distinction between large deformation and large distortion for anisotropic materials (open access)

On the distinction between large deformation and large distortion for anisotropic materials

A motion involves large distortion if the ratios of principal stretches differ significantly from unity. A motion involves large deformation if the deformation gradient tensor is significantly different from the identity. Unfortunately, rigid rotation fits the definition of large deformation, and models that claim to be valid for large deformation are often inadequate for large distortion. An exact solution for the stress in an idealized fiber-reinforced composite is used to show that conventional large deformation representations for transverse isotropy give errant results. Possible alternative approaches are discussed.
Date: February 24, 2000
Creator: BRANNON,REBECCA M.
Object Type: Article
System: The UNT Digital Library
Integration of Multiple Contractors with Performance Type of Contracts (open access)

Integration of Multiple Contractors with Performance Type of Contracts

The management practices, procedures, and processes that are suited to managing Management and Operation (M&O) type of contracts at Department of Energy (DOE) sites, which were cost reimbursement with award fee, are not well suited to managing contracts where fee is determined by performance metrics. Thus a different style of management, requiring substantial revamping of the management process, is needed. This shift in philosophy also requires a dramatic shift in culture. This paper will describe how these changes are being managed at the River Protection Project (RPP), located at the DOE's Hanford Site in Washington State, one of DOE's largest and highest risk environmental clean-up project.
Date: September 24, 2000
Creator: BURDGE, L.F.
Object Type: Article
System: The UNT Digital Library
III-Sb (001) growth surfaces: Structure and island nucleation (open access)

III-Sb (001) growth surfaces: Structure and island nucleation

The authors have determined the reconstructions present on AlSb and GaSb(001) under conditions typical for device growth by molecular beam epitaxy. Within the range of Sb flux and temperature where the diffraction pattern is nominally (1 x 3), three distinct (4 x 3) reconstructions actually occur. The three structures are different than those previously proposed for these growth conditions, with two incorporating mixed III-V dimers on the surface. The presence of these hetero-dimers in the top Sb layer leads to an island nucleation and growth mechanism fundamentally different than for other III-V systems.
Date: April 24, 2000
Creator: Barvoso-Carter, W.; Bracker, A. S.; Culbertson, J. C.; Nosho, B. Z.; Shanabrook, B. V.; Whitman, L. J. et al.
Object Type: Article
System: The UNT Digital Library
Photoisomerization and photodissociation dynamics of reactive free radicals (open access)

Photoisomerization and photodissociation dynamics of reactive free radicals

The photofragmentation pathways of chemically reactive free radicals have been examined using the technique of fast beam photofragment translational spectroscopy. Measurements of the photodissociation cross-sections, product branching ratios, product state energy distributions, and angular distributions provide insight into the excited state potential energy surfaces and nonadiabatic processes involved in the dissociation mechanisms. Photodissociation spectroscopy and dynamics of the predissociative {tilde A}{sup 2}A{sub 1} and {tilde B}{sup 2}A{sub 2} states of CH{sub 3}S have been investigated. At all photon energies, CH{sub 3} + S({sup 3}P{sub j}), was the main reaction channel. The translational energy distributions reveal resolved structure corresponding to vibrational excitation of the CH{sub 3} umbrella mode and the S({sup 3}P{sub j}) fine-structure distribution from which the nature of the coupled repulsive surfaces is inferred. Dissociation rates are deduced from the photofragment angular distributions, which depend intimately on the degree of vibrational excitation in the C-S stretch. Nitrogen combustion radicals, NCN, CNN and HNCN have also been studied. For all three radicals, the elimination of molecular nitrogen is the primary reaction channel. Excitation to linear excited triplet and singlet electronic states of the NCN radical generates resolved vibrational structure of the N{sub 2} photofragment. The relatively low fragment rotational excitation …
Date: August 24, 2000
Creator: Bise, Ryan T.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Measurement of sin2{Beta} From J/{Psi} K{Sub S} Decays (open access)

Measurement of sin2{Beta} From J/{Psi} K{Sub S} Decays

The CP-violating parameter sin 2{beta} is directly measured using 110 pb{sup {minus}1} of data accumulated with the CDF detector at the Fermilab {anti p}p Tevatron collider operating at {radical}s = 1.8 TeV. The signal consists of 395 {+-} 31 B{sub d}{sup 0} {r{underscore}arrow} J/{psi} K{sub s} events. Three tagging methods are used to identify the type of B meson at production (B{sub d}{sup 0} or {anti B}{sub d}{sup 0}). From the CP asymmetry, sin 2{beta} is measured to be 0.79 {sub {minus}0.44}{sup +0.41}, consistent with Standard Model predictions. Sin 2{beta} is in the interval 0 {lt} sin2{beta} {lt} 1 at the 93% confidence level.
Date: January 24, 2000
Creator: Blocker, C. A.
Object Type: Article
System: The UNT Digital Library
Top physics from Run 1 and Run 2 prospects at CDF (open access)

Top physics from Run 1 and Run 2 prospects at CDF

None
Date: October 24, 2000
Creator: Blusk, Steven R.
Object Type: Article
System: The UNT Digital Library
Kosovo: U.S. and Allied Military Operations (open access)

Kosovo: U.S. and Allied Military Operations

None
Date: July 24, 2000
Creator: Bowman, Steven R.
Object Type: Report
System: The UNT Digital Library
Develop Solid State Laser Sources for High Resolution Video Projection Systems (open access)

Develop Solid State Laser Sources for High Resolution Video Projection Systems

Magic Lantern and Honeywell FM and T worked together to develop lower-cost, visible light solid-state laser sources to use in laser projector products. Work included a new family of video displays that use lasers as light sources. The displays would project electronic images up to 15 meters across and provide better resolution and clarity than movie film, up to five times the resolution of the best available computer monitors, up to 20 times the resolution of television, and up to six times the resolution of HDTV displays. The products that could be developed as a result of this CRADA could benefit the economy in many ways, such as: (1) Direct economic impact in the local manufacture and marketing of the units. (2) Direct economic impact in exports and foreign distribution. (3) Influencing the development of other elements of display technology that take advantage of the signals that these elements allow. (4) Increased productivity for engineers, FAA controllers, medical practitioners, and military operatives.
Date: October 24, 2000
Creator: Brickeen, B.K.
Object Type: Report
System: The UNT Digital Library
Welding Behavior of Free Machining Stainless Steel (open access)

Welding Behavior of Free Machining Stainless Steel

The weld solidification and cracking behavior of sulfur bearing free machining austenitic stainless steel was investigated for both gas-tungsten arc (GTA) and pulsed laser beam weld processes. The GTA weld solidification was consistent with those predicted with existing solidification diagrams and the cracking response was controlled primarily by solidification mode. The solidification behavior of the pulsed laser welds was complex, and often contained regions of primary ferrite and primary austenite solidification, although in all cases the welds were found to be completely austenite at room temperature. Electron backscattered diffraction (EBSD) pattern analysis indicated that the nature of the base metal at the time of solidification plays a primary role in initial solidification. The solid state transformation of austenite to ferrite at the fusion zone boundary, and ferrite to austenite on cooling may both be massive in nature. A range of alloy compositions that exhibited good resistance to solidification cracking and was compatible with both welding processes was identified. The compositional range is bounded by laser weldability at lower Cr{sub eq}/Ni{sub eq} ratios and by the GTA weldability at higher ratios. It was found with both processes that the limiting ratios were somewhat dependent upon sulfur content.
Date: July 24, 2000
Creator: Brooks, John A.; Robino, Charles V.; Headley, Thomas J. & Michael, Joseph R.
Object Type: Article
System: The UNT Digital Library
Final report on the National Conference of State Legislatures project 'Assistance to State Legislatures on Alternative Fuel Vehicle Issues' (open access)

Final report on the National Conference of State Legislatures project 'Assistance to State Legislatures on Alternative Fuel Vehicle Issues'

This report assesses the effectiveness of state alternative fuel vehicle incentives and suggests incentives that might encourage new vehicle technologies. It does not assess whether a state should promote alternative fuel vehicles or whether such vehicles are the most effective means to reduce air pollution.
Date: July 24, 2000
Creator: Brown, Matthew & Sundeen, Matt
Object Type: Report
System: The UNT Digital Library
Towards automatic planning for manufacturing generative processes (open access)

Towards automatic planning for manufacturing generative processes

Generative process planning describes methods process engineers use to modify manufacturing/process plans after designs are complete. A completed design may be the result from the introduction of a new product based on an old design, an assembly upgrade, or modified product designs used for a family of similar products. An engineer designs an assembly and then creates plans capturing manufacturing processes, including assembly sequences, component joining methods, part costs, labor costs, etc. When new products originate as a result of an upgrade, component geometry may change, and/or additional components and subassemblies may be added to or are omitted from the original design. As a result process engineers are forced to create new plans. This is further complicated by the fact that the process engineer is forced to manually generate these plans for each product upgrade. To generate new assembly plans for product upgrades, engineers must manually re-specify the manufacturing plan selection criteria and re-run the planners. To remedy this problem, special-purpose assembly planning algorithms have been developed to automatically recognize design modifications and automatically apply previously defined manufacturing plan selection criteria and constraints.
Date: May 24, 2000
Creator: CALTON,TERRI L.
Object Type: Article
System: The UNT Digital Library