Adaptive Position and Orientation Regulation for the Camera-in-hand Problem (open access)

Adaptive Position and Orientation Regulation for the Camera-in-hand Problem

None
Date: May 31, 2001
Creator: Setlur, P
System: The UNT Digital Library
The China Motor Systems Energy Conservation Program: A major national initiative to reduce motor system energy use in China (open access)

The China Motor Systems Energy Conservation Program: A major national initiative to reduce motor system energy use in China

Electric motor systems are widely used in China to power fans, pumps, blowers, air compressors, refrigeration compressors, conveyers, machinery, and many other types of equipment. Overall, electric motor systems consume more than 600 billion kWh annually, accounting for more than 50 percent of China's electricity use. There are large opportunities to improve the efficiency of motor systems. Electric motors in China are approximately 2-4 percent less efficient on average than motors in the U.S. and Canada. Fans and pumps in China are approximately 3-5 percent less efficient than in developed countries. Even more importantly, motors, fans, pumps, air compressors and other motor-driven equipment are frequently applied with little attention to system efficiency. More optimized design, including appropriate sizing and use of speed control strategies, can reduce energy use by 20 percent or more in many applications. Unfortunately, few Chinese enterprises use or even know about these energy-saving practices. Opportunities for motor system improvements are probably greater in China than in the U.S. In order to begin capturing these savings, China is establishing a China Motor Systems Energy Conservation Program. Elements of this program include work to develop minimum efficiency standards for motors, a voluntary ''green motor'' labeling program for high-efficiency …
Date: May 31, 2001
Creator: Nadel, Steven; Wang, Wanxing; Liu, Peter & McKane, Aimee T.
System: The UNT Digital Library
CYP1B1 expression, a potential risk factor for breast cancer (open access)

CYP1B1 expression, a potential risk factor for breast cancer

CYP1B1 expression in non-tumor breast tissue from breast cancer patients and cancer-free individuals was determined to test the hypothesis that high CYP1B1 expression is a risk factor for breast cancer. Large interindividual variations in CYP1B1 expression were found with CYP1B1 levels notably higher in breast cancer patients than cancer-free individuals. The results indicate that CYP1B1 might play a role in breast cancer either through increased PAH activation or through metabolism of endogenous estrogen to a carcinogenic derivative.
Date: May 31, 2001
Creator: Goth-Goldstein, Regine; Erdmann, Christine A. & Russell, Marion
System: The UNT Digital Library
The D-Zero Run II Detector and physics prospects (open access)

The D-Zero Run II Detector and physics prospects

The DO Detector at Fermilab is currently undergoing an extensive upgrade to participate in the Run II data taking which shall begin on March 1, 2001. The design of the detector meets the requirements of the high luminosity environment provided by the accelerator. This paper describes the upgraded detector subsystems and gives a brief outline of the physics prospects associated with the upgrade.
Date: May 31, 2001
Creator: Parashar, Neeti
System: The UNT Digital Library
Evaluation of MOSFETS and IGBTS for Pulsed Power Applications (open access)

Evaluation of MOSFETS and IGBTS for Pulsed Power Applications

Single solid-state devices or arrays of solid-state devices are being incorporated into many pulsed power applications as a means of generating fast, high-power, high repetition-rate pulses and ultimately replacing hard tubes and thyratrons. While vendors' data sheets provide a starting point for selecting solid-state devices, most data sheets do not have sufficient information to determine performance in a pulsed application. To obtain this relevant information, MOSFET's and IGBT's from a number of vendors have been tested to determine rise times, fall times and current handling capabilities. The emphasis is on the evaluation of devices that can perform in the range of 100ns pulse widths and the test devices must be capable of switching 1000 volts or greater at a pulsed current of at least 25 amperes. Additionally, some devices were retest with a series magnetic switch to evaluate the effects on switching parameters and specifically rise times. All devices were evaluated under identical conditions and the complete test results are presented.
Date: May 31, 2001
Creator: Hickman, B. & Cook, E.
System: The UNT Digital Library
Influence of microstructure on electrical properties of diluted GaNxAs1-x formed by nitrogen implantation (open access)

Influence of microstructure on electrical properties of diluted GaNxAs1-x formed by nitrogen implantation

None
Date: May 31, 2001
Creator: Jasinski, J.; Yu, K. M.; Walukiewicz, W.; Washburn, J. & Liliental-Weber, Z.
System: The UNT Digital Library
A Load Balanced Domain Decomposition Method Using Wavelet Analysis (open access)

A Load Balanced Domain Decomposition Method Using Wavelet Analysis

Wavelet Analysis provides an orthogonal basis set which is localized in both the physical space and the Fourier transform space. We present here a domain decomposition method that uses wavelet analysis to maintain roughly uniform error throughout the computation domain while keeping the computational work balanced in a parallel computing environment.
Date: May 31, 2001
Creator: Jameson, L; Johnson, J & Hesthaven, J
System: The UNT Digital Library
Making industrial energy efficiency mainstream and profitable: Where public benefit and private interests intersect (open access)

Making industrial energy efficiency mainstream and profitable: Where public benefit and private interests intersect

In 1996, the US Department of Energy s Office of Industrial Technologies (OIT) Motor Challenge program began a unique collaboration with industry called the Allied Partner program. Partnerships were sought with equipment suppliers and manufacturers, utilities, consultants, and state agencies that had extensive existing relationships with industrial customers. Partners were neither paid nor charged a fee for participation. The assumption was that these relationships could serve as the foundation for conveying a motor system efficiency message to many more industrial facilities than could be reached through a typical government-to-end-user program model. A substantial effort was made to engage industrial suppliers in delivering program information as part of their customer interactions. A recent independent evaluation of the Motor Challenge program attributes $16.9 million or nearly 67 percent of the total annual program energy savings to the efforts of Allied Partners in the first three years of operation.In 1997, the Compressed Air Challenge(R) (CAC) was developed as an outgrowth of the partnership concept. In this model, OIT is one of 15 sponsors who collaborated to create a national program of compressed air system training. The CAC has gone a step further by setting up a development and deployment model based on shared …
Date: May 31, 2001
Creator: McKane, Aimee T.; Tutterow, Vestal & Cockrill, Chris
System: The UNT Digital Library
Measurement of Low Level Explosives Reaction in Gauged Multi-Dimensional Steven Impact Tests (open access)

Measurement of Low Level Explosives Reaction in Gauged Multi-Dimensional Steven Impact Tests

The Steven Test was developed to determine relative impact sensitivity of metal encased solid high explosives and also be amenable to two-dimensional modeling. Low level reaction thresholds occur at impact velocities below those required for shock initiation. To assist in understanding this test, multi-dimensional gauge techniques utilizing carbon foil and carbon resistor gauges were used to measure pressure and event times. Carbon resistor gauges indicated late time low level reactions 200-540 {micro}s after projectile impact, creating 0.39-2.00 kb peak shocks centered in PBX 9501 explosives discs and a 0.60 kb peak shock in a LX-04 disk. Steven Test modeling results, based on ignition and growth criteria, are presented for two PBX 9501 scenarios: one with projectile impact velocity just under threshold (51 m/s) and one with projectile impact velocity just over threshold (55 m/s). Modeling results are presented and compared to experimental data.
Date: May 31, 2001
Creator: Niles, A M; Garcia, F; Greenwood, D W; Forbes, J W; Tarver, C M; Chidester, S K et al.
System: The UNT Digital Library
Pressure Wave Measurements from Thermal Cook-Off of an HMX Based High Explosive PBX 9501 (open access)

Pressure Wave Measurements from Thermal Cook-Off of an HMX Based High Explosive PBX 9501

A better understanding of thermal cook-off is important for safe handling and storing explosive devices. A number of safety issues exist about what occurs when a cased explosive thermally cooks off. For example, violence of the events as a function of confinement are important for predictions of collateral damage. This paper demonstrates how adjacent materials can be gauged to measure the resulting pressure wave and how this wave propagates in this adjacent material. The output pulse from the thermal cook-off explosive containing fixture is of obvious interest for assessing many scenarios.
Date: May 31, 2001
Creator: Garcia, F.; Forbes, J. W.; Tarver, Craig M.; Urtiew, P. A.; Greenwood, D. W. & Vandersall, K. S.
System: The UNT Digital Library
Reconstruction of FXR Beam Conditions (open access)

Reconstruction of FXR Beam Conditions

Beam-envelope radius, envelope angle, and beam emittance can be derived from measurements of beam radius for at least three different transport conditions. We have used this technique to reconstruct exit parameters from the FXR injector and accelerator. We use a diamagnetic loop (DML) to measure the magnetic moment of the high current beam. With no assumptions about radial profile, we can derive the beam mean squire radius from the moment under certain easily met conditions. Since it is this parameter which is required for the reconstruction, it is evident that the DML is the ideal diagnostic for this technique. The simplest application of this technique requires at least three shots for a reconstruction but in reality requires averaging over many more shots because of shot to shot variation. Since DML measurements do not interfere with the beam, single shot time resolved measurements of the beam parameters appear feasible if one uses an array of at least three DMLs separated by known transport conditions.
Date: May 31, 2001
Creator: Nexen, W E; Scarpetti, R D & Zentler, J
System: The UNT Digital Library
Analysis of Statically Indeterminate Tie-Down Systems (open access)

Analysis of Statically Indeterminate Tie-Down Systems

The purpose of this analysis is to propose and qualify a design of the tie-down system for the High Level Waste (HLW) pump/agitator transport container.
Date: May 30, 2001
Creator: Wu, T.
System: The UNT Digital Library
A comparison of three programming models for adaptive applications on the Origin2000 (open access)

A comparison of three programming models for adaptive applications on the Origin2000

Adaptive applications have computational workloads and communication patterns which change unpredictably at runtime, requiring dynamic load balancing to achieve scalable performance on parallel machines. Efficient parallel implementations of such adaptive applications is therefore a challenging task. In this paper, we compare the performance of and the programming effort required for two major classes of adaptive applications under three leading parallel programming models on an SGI Origin2000 system, a machine which supports all three models efficiently. Results indicate that the three models deliver comparable performance; however, the implementations differ significantly beyond merely using explicit messages versus implicit loads/stores even though the basic parallel algorithms are similar. Compared with the message-passing (using MPI) and SHMEM programming models, the cache-coherent shared address space (CC-SAS) model provides substantial ease of programming at both the conceptual and program orchestration levels, often accompanied by performance gains. However, CC-SAS currently has portability limitations and may suffer from poor spatial locality of physically distributed shared data on large numbers of processors.
Date: May 30, 2001
Creator: Shan, Hongzhang; Singh, Jaswinder Pal; Oliker, Leonid & Biswas, Rupak
System: The UNT Digital Library
Cooperative MPC&A Enhancements at Russian Navy Sites (open access)

Cooperative MPC&A Enhancements at Russian Navy Sites

U.S. MPC&A cooperation with the Russian Federation (RF) Navy is based on a Joint Statement signed in 1996 to protect Highly Enriched Uranium (HEU) fresh fuel used for nuclear propulsion. The Russian Federation Navy is the largest owner in Russia of highly enriched uranium, both in the form of fresh nuclear fuel, and in the form of slightly irradiated fuel with a long cooling time after irradiation. As a result of this agreement, projects began at the Northern Fleet Fresh Fuel Storage Facility (Site 49) and Refueling Ship PM-63. Initial projects provided upgrades for RF Navy HEU fresh fuel storage facilities, beginning with a land-based facility near Murmansk and later adding other land-based and ship-based fresh fuel storage facilities. Additional protocols (December 1997, January 1999, and March 2000) significantly expanded cooperation to include all HEU fuel under RF Navy control. To date, it is estimated that tens of metric tons of HEU have been secured - enough to construct hundreds of nuclear devices. It was determined that the cooperation would be coordinated by the Russian Research Center, Kurchatov Institute. This paper describes the history of the Program development, its stages, current status, scale of the work and prospects.
Date: May 30, 2001
Creator: Nelson, N. N.; O'Shell, P.; Hendrickson, S.; Sukhoruchkin, V.; Antipov, S.; Melkhov, E. et al.
System: The UNT Digital Library
Digital Radiography of a Drop Tested 9975 Radioactive Materials Packaging (open access)

Digital Radiography of a Drop Tested 9975 Radioactive Materials Packaging

This paper discusses the use of radiography as a tool for evaluating damage to radioactive material packaging subjected to regulatory accident conditions. The Code of Federal Regulations, 10 CFR 71, presents the performance based requirements that must be used in the development (design, fabrication and testing) of a radioactive material packaging. The use of various non-destructive examination techniques in the fabrication of packages is common. One such technique is the use of conventional radiography in the examination of welds. Radiography is conventional in the sense that images are caught one at a time on film stock. Most recently, digital radiography has been used to characterize internal damage to a package subjected to the 30-foot hypothetical accident conditions (HAC) drop. Digital radiography allows for real time evaluation of the item being inspected. This paper presents a summary discussion of the digital radiographic technique and an example of radiographic results of a 9975 package following the HAC 30-foot drop.
Date: May 30, 2001
Creator: Blanton, P.S.
System: The UNT Digital Library
Dynamic Analysis of 9975 Shipping Package without Overpack Subjected to 55-Foot Drop (open access)

Dynamic Analysis of 9975 Shipping Package without Overpack Subjected to 55-Foot Drop

This paper discusses the evaluation of the dynamic response of a 9975 shipping package subjected to a load of 55-foot lateral drop without its overpack structure (fiberboard and drum).
Date: May 30, 2001
Creator: Wu, T.
System: The UNT Digital Library
Investigation of the Sintering Process Using Non-Contact Electromagnetic Acoustic Transducers (open access)

Investigation of the Sintering Process Using Non-Contact Electromagnetic Acoustic Transducers

In-situ characterizations of green state part density and sintering state have long been desired in the powder metal community. Recent advances in non-contact electromagnetic acoustic transducer (EMAT) technology have enabled in-situ monitoring of acoustic amplitude and velocity as sintering proceeds. Samples were made from elemental powders of Al (99.99%), Al (99.7%), Ag, (99.99%), Cu (99.99%) and Fe (99.9%). The powders were pressed in a uniaxial die and examined with acoustic waves for changes in velocity and amplitude during sintering for the samples containing Al, Ag, and Cu. The changes in acoustic properties were correlated with sample microstructures and mechanical properties. Evolution of a series of reverberating echoes during sintering is shown to provide information on the state of sintering, and changes in sintering kinetics as well as having the potential for detection of interior flaws.
Date: May 30, 2001
Creator: Foley, James C.; Rehbein, David K. & Barnard, Daniel J.
System: The UNT Digital Library
Keck Adaptive Optics Observations of TW Hydrae Association Members (open access)

Keck Adaptive Optics Observations of TW Hydrae Association Members

Adaptive optics (AO) on 8-10 m telescopes is an enormously powerful tool for studying young nearby stars. It is especially useful for searching for companions. Using AO on the 10-m W.M. Keck II telescope we have measured the position of the brown dwarf companion to TWA5 and resolved the primary into an 0.055{double_prime} double. Over the next several years follow-up astrometry should permit an accurate determination of the masses of these young stars. We have also re-observed the candidate extrasolar planet TWAGB, but measurements of its motion relative to TWA6A are inconclusive. We are carrying out a search for new planetary or brown dwarf companions to TWA stars and, if current giant planet models are correct, are currently capable of detecting a 1 Jupiter-mass companion at {approx} 1.0{double_prime} and a 5 Jupiter-mass companion at {approx} 0.5{double_prime} around a typical TWA member.
Date: May 30, 2001
Creator: Macintosh, B; Max, C; Zuckerman, B; Becklin, E E; Kaisler, D; Lowrance, P et al.
System: The UNT Digital Library
The Kinetic Stabilizer: A Route to Simpler Tandem Mirror Systems? (open access)

The Kinetic Stabilizer: A Route to Simpler Tandem Mirror Systems?

This paper discusses a new approach to an MHD stabilizing technique for magnetic fusion systems of the axisymmetric ''open-ended'' variety. The concept is adaptable to tandem-mirror systems and would result in a major simplification of such systems, accompanied by a substantial improvement in their confinement characteristics, The paper first discusses the present impetus to find a simpler and less expensive route to fusion than that offered by the mainline approach, the tokamak. The history of magnetic fusion research shows that closed and open systems exhibit very different confinement characteristics. Closed systems, such as the tokamak, the stellarator, or the reversed-field pinch have cross-field transport that is dominated by plasma turbulence. By contrast, there are examples of open-systems where turbulence, if present at all, was at such low levels that the transport agreed with ''classical'' predictions. The clearest examples are ones in which the field geometry was axiymmetric. However axisymmetric mirror systems are subject to MHD instability. Thus in the years following the famous Ioffe experiment, most open systems have employed asymmetric magnetic fields, with attendant problems of complexity and enhanced cross-field transport. This paper proposes a new means of stabilizing axisymmetric mirror-based systems. The idea, called the ''Kinetic Stabilizer'' has …
Date: May 30, 2001
Creator: Post, R
System: The UNT Digital Library
Modeling transport in fractured porous media with the random-walk particle method: The transient activity range and the particle-transfer probability (open access)

Modeling transport in fractured porous media with the random-walk particle method: The transient activity range and the particle-transfer probability

None
Date: May 30, 2001
Creator: Pan, Lehua & Bodvarsson, Gudmundur S.
System: The UNT Digital Library
A pre- and post-processor for the ICOOL muon transport code (open access)

A pre- and post-processor for the ICOOL muon transport code

ICOOL[1] is a Fortran77 macroparticle transport code widely used by researchers to study the front end of a neutrino factory/muon collider[2]. In part due to the desire that ICOOL be usable over multiple computer platforms and operating systems, the code uses simple text files for input/output services. This choice together with user-driven requests for greater and greater choice of lattice element type and configuration has led to ICOOL input decks becoming rather difficult to compose and modify easily. Moreover, the lack of a standard graphical post-processor has prevented many ICOOL users from extracting all but the most simple results from the output files. Here I present two attempts to improve this situation: First, a simple but quite general graphical pre-processor (NIME) written in the Tcl/TK[3] to permit users to write and maintain ASCII-formatted input files by use of simple macro definitions and expansions. Second, an interactive post-processor written in Fortran90 and NCAR graphics, which allows users to define, extract, and then examine the behavior of various particle subsets. In this paper I show some examples of use of both the pre- and post-processor for a standard ICOOL run.
Date: May 30, 2001
Creator: Fawley, W. M.
System: The UNT Digital Library
Studies of the front end of a neutrino factory (open access)

Studies of the front end of a neutrino factory

A neutrino factory employs muons which are produced, collected, cooled, accelerated and then stored so that their eventual decay produces an intense neutrino beam. A general description may be found in the paper by Geer [S. Geer, Phys. Rev. D, 57, 1 (1998)], and two upcoming Comments on Nuclear and Particle Physics articles [S. Geer, ''Future prospects for muon facilities'', see http://www-mucool.fnal.gov/mcnotes/muc0154.ps; also A. M. Sessler, ''Neutrino Factories: The Facility'', http://www-mucool.fnal.gov/mcnotes/muc0155.pdf]. In this contribution, we use analytic and numerical tools to investigate the performance of the front end of a neutrino factory. This region starts just after the target and ends just prior to the recirculating accelerators. Extensive previous work has resulted in designs used in the Fermilab Study of 1999-2000 and the Brookhaven Study of 2000-2001. Here we explore variations away from these particular designs, seeking possible improvements in final muon output, risk reduction, and ultimate cost. Our studies include changes in the overall front end geometry through optimization of the induction linac design and variations of the rf frequency in the cooling channel acceleration, and initial exploration of the use of helical wiggler fields to increase the range of initial muon energies that are captured.
Date: May 30, 2001
Creator: Fawley, William; Penn, Gregory; Sessler, Andrew & Wurtele, Jonathan
System: The UNT Digital Library
2-D Simulations of Drainage Winds and Diffusion Compared to Observations (open access)

2-D Simulations of Drainage Winds and Diffusion Compared to Observations

A vertically integrated dynamical drainage flow model is developed from conservation equations for momentum and mass in a terrain-following coordinate system. Wind fields from the dynamical model drive a Monte Carlo transport and diffusion model. The model needs only topographic data, an Eulerian or Lagrangian time scale and a surface drag coefficient for input data, and can be started with a motionless atmosphere. Model wind and diffusion predictions are compared to observations from the rugged Geysers CA area. Model winds generally agree with observed surface winds, and in some cases may give better estimates of area-averaged flow than point observations. Tracer gas concentration contours agree qualitatively with observed contours, and point predictions of maximum concentrations were correctly predicted to within factors of 2 to 10. Standard statistical tests of model skill showed that the accuracy of the predictions varied significantly from canyon to canyon in the Geysers are a. Model wind predictions are also compared to observations from the Savannah River Plant of SC which has gently rolling terrain. The model correctly simulated the slower development of drainage winds and slower deepening of the drainage layer in the Savannah River Valley, relative to the Geysers CA simulations. The SC simulations …
Date: May 29, 2001
Creator: Garrett, A. J.
System: The UNT Digital Library
Aging of Polyurethane Foam Insulation in Simulated Refrigerator Panels--Three-Year Results with Third-Generation Blowing Agents (open access)

Aging of Polyurethane Foam Insulation in Simulated Refrigerator Panels--Three-Year Results with Third-Generation Blowing Agents

Laboratory data are presented on the effect of constant-temperature aging on the apparent thermal conductivity of polyurethane foam insulation for refrigerators and freezers. The foam specimens were blown with HCFC-141b and with three of its potential replacements--HFC-134a, HFC-245fa, and cyclopentane. Specimens were aged at constant temperatures of 90 F, 40 F, and -10 F. Thermal conductivity measurements were made on two types of specimens: full-thickness simulated refrigerator panels containing foam enclosed between solid plastic sheets, and thin slices of core foam cut from similar panels. Results are presented for the first three years of a multi-year aging study. Preliminary comparisons of measured data with predictions of a mathematical aging model are presented.
Date: May 29, 2001
Creator: Wilkes, K. E.
System: The UNT Digital Library