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Physical effects of infrared quark eigenmodes in LQCD
A truncated determinant algorithm is used to study the physical effects of the quark eigenmodes associated with eigenvalues below 300 MeV. This initial study focuses on coarse lattices (with O(a{sup 2}) improved gauge action), light internal quark masses and large physical volumes. Four bellweather full QCD processes are discussed: topological charge distributions, the eta prime propagator, string breaking as observed in the static energy and the rho decay into two pions.
Date:
October 7, 1999
Creator:
A. Duncan, E. Eichten and H. Thacker
Object Type:
Article
System:
The UNT Digital Library
Pre-conceptual Design of a Rapid Cycling Medical Synchrotron
N/A
Date:
October 1, 1999
Creator:
A., Favale; Myers, T.; Rathke, J.; Sredniawski, J.; Todd, A.; Barton, D. et al.
Object Type:
Report
System:
The UNT Digital Library
Observations of Non-Close-Packed Arrangements in Multilayers of Passivated Gold Clusters
The stacking of second and third layers of supercrystals of self-assembled passivated gold nanoparticles has been investigated using transmission electron microscopy. We report for the first time nanoparticles occupying the twofold saddle site in the third layer.
Date:
October 5, 1999
Creator:
AINDOW, M.; Brown, P.; Kiely, C. J.; Wellner, A. & Wilcoxon, Jess P.
Object Type:
Article
System:
The UNT Digital Library
Analysis of Tracer Tests with Multirate Diffusion Models: Recent Results and Future Directions within the WIPP Project
A series of single-well injection-withdrawal (SWIW) and two-well convergent-flow (TWCF) tracer tests were conducted in the Culebra dolomite at the WIPP site in late 1995 and early 1996. Modeling analyses over the past year have focused on reproducing the observed mass-recovery curves and understanding the basic physical processes controlling tracer transport in SWIW and TWCF tests. To date, specific modeling efforts have focused on five SWIW tests and one TWCF pathway at each of two different locations (H-11 and H-19 hydropads). An inverse parameter-estimation procedure was implemented to model the SWIW and TWCF tests with both traditional and multirate double-porosity formulations. The traditional model assumes a single diffusion rate while the multirate model uses a first-order approximation to model a continuous distribution of diffusion coefficients. Conceptually, the multirate model represents variable matrix block sizes within the Culebra as observed in geologic investigations and also variability in diffusion rates within the matrix blocks as observed with X-ray imaging in the laboratory. Single-rate double-porosity models cannot provide an adequate match to the SWIW data. Multirate double-porosity models provide excellent fits to all five SWIW mass-recovery curves. Models of the TWCF tests show that, at one location, the tracer test can be modeled …
Date:
October 1, 1999
Creator:
ALTMAN, SUSAN J.; HAGGERTY, ROY; MCKENNA, SEAN A. & MEIGS, LUCY C.
Object Type:
Article
System:
The UNT Digital Library
Motion Planning for a Direct Metal Deposition Rapid Prototyping System
A motion planning strategy was developed and implemented to generate motion control instructions from solid model data for controlling a robotically driven solid free-form fabrication process. The planning strategy was tested using a PUMA type robot arm integrated into a LENS{trademark} (Laser Engineered Net Shape) system. Previous systems relied on a series of x, y, and z stages, to provide a minimal coordinated motion control capability. This limited the complexity of geometries that could be constructed. With the coordinated motion provided by a robotic arm, the system can produce three dimensional parts by ''writing'' material onto any face of existing material. The motion planning strategy relied on solid model geometry evaluation and exploited robotic positioning flexibility to allow the construction of geometrically complex parts. The integration of the robotic manipulator into the LENS{trademark} system was tested by producing metal parts directly from CAD models.
Date:
October 18, 1999
Creator:
AMES,ARLO L.; HENSINGER,DAVID M. & KUHLMANN,JOEL L.
Object Type:
Article
System:
The UNT Digital Library
Evaluation of cracking in the 241-AZ tank farm ventilation line at the Hanford Site
In the period from April to October of 1988, a series of welding operations on the outside of the AZ Tank Farm ventilation line piping at the Hanford Site produced unexpected and repeated cracking of the austenitic stainless steel base metal and of a seam weld in the pipe. The ventilation line is fabricated from type 304L stainless steel pipe of 24 inch diameter and 0.25 inch wall thickness. The pipe was wrapped in polyethylene bubble wrap and buried approximately 12 feet below grade. Except for the time period between 1980 and 1987, impressed current cathodic protection has been applied to the pipe since its installation in 1974. The paper describes the history of the cracking of the pipe, the probable cracking mechanisms, and the recommended future action for repair/replacement of the pipe.
Date:
October 20, 1999
Creator:
ANANTATMULA, R.P.
Object Type:
Article
System:
The UNT Digital Library
MIL-L-87177 and CLT:X-10 Lubricants Improve Electrical Connector Fretting Corrosion Behavior
We have conducted a fretting research project using MIL-L-87177 and CLT: X-10 lubricants on Nano-miniature connectors. When they were fretted without lubricant, individual connectors first exceeded our 0.5 ohm failure criteria from 2,341 to 45,238 fretting cycles. With additional fretting, their contact resistance increased to more than 100,000 ohms. Unmodified MIL-L-87177 lubricant delayed the onset of first failure to between 430,000 and over 20,000,000 fretting cycles. MIL-L-87177 modified by addition of Teflon powder delayed first failure to beyond 5 million fretting cycles. Best results were obtained when Teflon was used and also when both the straight and modified lubricants were poured into and then out of the connector. CLT: X-10 lubricant delayed the onset of first failure to beyond 55 million cycles in one test where a failure was actually observed and to beyond 20 million cycles in another that was terminated without failure. CLT: X-10 recovered an unlubricated connector driven deeply into failure, with six failed pins recovering immediately and four more recovering during an additional 420 thousand fretting cycles. MIL-L-87177 was not able to recover a connector under similar conditions.
Date:
October 12, 1999
Creator:
AUKLAND,NEIL R. & HANLON,JAMES T.
Object Type:
Article
System:
The UNT Digital Library
Roles and Delegation of Authority (R/DA) System
The processes of defining managerial roles and providing for delegation of authority are essential to any enterprise. At most large organizations, these processes are defined in policy manuals and through sets of standard operating procedures for many, if not all, business and administrative functions. Many of these staff-initiated, administrative functions require the routing of documents for approval to one or more levels of management. These employee-oriented, back office types of workflows tend to require more flexibility in determining to whom these documents should go to, while, at the same time, providing the responsible parties with the flexibility to delegate their approval authority or allow others to review their work. Although this practice is commonplace in manual, paper-based processes that exist in many organizations, it is difficult to provide the same flexibility in the more structured, electronic-based, workflow systems.
Date:
October 21, 1999
Creator:
Abbott, John P.; Hutchins, James C. & Schoch, David G.
Object Type:
Article
System:
The UNT Digital Library
Air Dispersion Modeling of Mine Waste in the Southeast Missouri Old Lead Belt
Past lead ore processing conducted in the Southeast Missouri Old Lead Belt since the 1700s has left numerous large areas of lead contamination in elevated piles of fine gravel waste called “chat” and dried-out tailings ponds. Wind suspension and atmospheric dispersion are known to transport these materials to the surrounding communities where the lead could pose a human health threat through inhalation or ingestion of the deposited contamination. The purpose of this study was to estimate potential wind suspension rates, perform dispersion modeling of the tailings and chat sources, and determine ground surface deposition rates and potential soil concentrations of lead in the surrounding areas. The results can be used to prioritize soil sampling locations, site air monitors, help identify the source of soil lead contamination, and to help develop remediation plans. Numerous, large complex sources in the region were parameterized into 33 area sources with the aid of digital aerial photos, digitized typographic maps, Geographic Information Systems (GIS) software, and site inspections. An AP-42 particulate emission model was used to estimate lower- and upper-bound hourly emission rates using six years of hourly wind speed data obtained from the St. Louis Airport. The emissions model accounted for wind speed, precipitation, …
Date:
October 1, 1999
Creator:
Abbott, Michael Lehman
Object Type:
Report
System:
The UNT Digital Library
Bin Set 1 Calcine Retrieval Feasibility Study
At the Department of Energy's Idaho Nuclear Technology and Engineering Center, as an interim waste management measure, both mixed high-level liquid waste and sodium bearing waste have been solidified by a calculation process and are stored in the Calcine Solids Storage Facilities. This calcined product will eventually be treated to allow final disposal in a national geologic repository. The Calcine Solids Storage Facilities comprise seven ''bit sets.'' Bin Set 1, the first to be constructed, was completed in 1959, and has been in service since 1963. It is the only bin set that does not meet current safe-shutdown earthquake seismic criteria. In addition, it is the only bin set that lacks built-in features to aid in calcine retrieval. One option to alleviate the seismic compliance issue is to transport the calcine from Bin Set 1 to another bin set which has the required capacity and which is seismically qualified. This report studies the feasibility of retrieving the calcine from Bi n Set 1 and transporting it into Bin Set 6 which is located approximately 650 feet away. Because Bin Set 1 was not designed for calcine retrieval, and because of the high radiation levels and potential contamination spread from the …
Date:
October 1, 1999
Creator:
Adams, R. D.; Berry, S. M.; Galloway, K. J.; Langenwalter, T. A.; Lopez, D. A.; Noakes, C. M. et al.
Object Type:
Report
System:
The UNT Digital Library
Charge exchange {rho}{sup zero}{pi}{sup +} photoproduction and implications for searches of exotic meson
The authors analyze the processes {rvec {gamma}} + p {r_arrow} {rho}{sup 0}{pi}{sup +}n at low momentum transfer focusing on a possibility of production of an exotic J{sup PC} = 1{-+} meson state. In particular they discuss polarization observables and conclude that linear photon polarization is instrumental for separating of the exotic wave.
Date:
October 1, 1999
Creator:
Afanasev, A. V. & Szczepaniak, A. P.
Object Type:
Article
System:
The UNT Digital Library
Hawaiian Monk Seal Epidemiology Plan: Health Assessment and Disease Status Studies
The following document provides a framework for incorporation of health and information to enhance recovery of the Hawaiian monk seal.
Date:
October 1999
Creator:
Aguirre, A. Alonso; Reif, John S. & Antonelis, George A.
Object Type:
Report
System:
The UNT Digital Library
CDEV-NT: Porting the Control Device Interface to Windows NT
In recent years the rapid increase in processing power of the personal computer has made it a significant competitor to high-end workstations for accelerator control and experimental physics applications. When the decreasing price of the PC and the availability of inexpensive commercial software is also considered, NT becomes a very attractive alternative to traditional UNIX systems. In order to simplify the integration of Personal Computers into our operating environment, we have ported the Control Device (CDEV) Interface to Windows NT. By supporting CDEV on this platform, we can provide routine access to our existing control system. Additionally, CDEV allows us to create an interface from our UNIX workstations to Windows NT applications (such as databases) that are significantly less expensive on the PC. This paper details the pitfalls we encountered during the software migration and will provide a direct comparison between the performance of CDEV applications on UNIX and NT. P articular attention is paid to network performance, which represents most of the overhead of this transition.
Date:
October 1, 1999
Creator:
Akers, W.; Chen, J. & Watson, C.
Object Type:
Article
System:
The UNT Digital Library
MAGNETO-CHEMICAL CHARACTER STUDIES OF NOVEL FE CATALYSTS FOR COAL LIQUEFACTION
The primary objectives of research during this period were: (1) To prepare iron-cobalt-molybdenum trioxide catalysts using co-precipitation method; (2) To examine the surface character of these catalysts with CO and Syngas as probe molecules by FTIR spectroscopy; and (3) To examine the magnetic properties of these catalysts using NMR and Magnetization techniques.
Date:
October 1, 1999
Creator:
Akundi, Murty A.
Object Type:
Report
System:
The UNT Digital Library
EVALUATION OF COATINGS AND MORTARS FOR PROTECTION OF CONCRETE COOLING TOWER STRUCTURES FROM MICROBIOLOGICALLY INFLUENCED CORROSION IN GEOTHERMAL POWER PLANTS.
None
Date:
October 1, 1999
Creator:
Allan, M. L.
Object Type:
Report
System:
The UNT Digital Library
GROUND WATER PROTECTION ISSUES WITH GEOTHERMAL HEAT PUMPS
Closed loop vertical boreholes used with geothermal heat pumps are grouted to facilitate heat transfer and prevent ground water contamination. The grout must exhibit suitable thermal conductivity as well as adequate hydraulic sealing characteristics. Permeability and infiltration tests were performed to assess the ability of cementitious grout to control vertical seepage in boreholes. It was determined that a superplasticized cement-sand grout is a more effective borehole sealant than neat cement over a range of likely operational temperatures. The feasibility of using non-destructive methods to verify bonding in heat exchangers is reviewed.
Date:
October 1, 1999
Creator:
Allan, M. L. & Philippacopoulos, A. J.
Object Type:
Article
System:
The UNT Digital Library
Modeling Manufacturing Processes to Mitigate Technological Risk
An economic model is a tool for determining the justifiable cost of new sensors and subsystems with respect to value and operation. This process balances the R and D costs against the expense of maintaining current operations and allows for a method to calculate economic indices of performance that can be used as control points in deciding whether to continue development or suspend actions. The model can also be used as an integral part of an overall control loop utilizing real-time process data from the sensor groups to make production decisions (stop production and repair machine, continue and warn of anticipated problems, queue for repairs, etc.). This model has been successfully used and deployed in the CAFE Project. The economic model was one of seven (see Fig. 1) elements critical in developing an investment strategy. It has been successfully used in guiding the R and D activities on the CAFE Project, suspending activities on three new sensor technologies, and continuing development o f two others. The model has also been used to justify the development of a new prognostic approach for diagnosing machine health using COTS equipment and a new algorithmic approach. maintaining current operations and allows for a method …
Date:
October 24, 1999
Creator:
Allgood, G. O. & Manges, W. W.
Object Type:
Article
System:
The UNT Digital Library
High Efficiency Release Targets for Use at ISOL Facilities: Computational Design
This report describes efforts made at the oak Rklge NatiOnrd Laboratory to design high- efficiency-release targets that simultaneously incorporate the short diffusion lengths, high permeabilities, controllable temperatures, and heat-removal properties required for the generation of useful radioactive ion beam (RIB) intensities for nuclear physics and astrophysics research using the isotope separation on-line (ISOL) technique. Short diffusion lengths are achieved either by using thin fibrous target materials or by coating thin layers of selected target material onto low-density carbon fibers such as reticulated-vitreous-carbon fiber (RVCF) or carbon-bonded-carbon fiber (CBCF) to form highly permeable composite target matrices. Computational studies that simulate the generation and removal of primary beam deposited heat from target materials have been conducted to optimize the design of targetheat-sink systems for generating RIBs. The results derived from diffusion release-rate simulation studies for selected targets and thermal analyses of temperature distributions within a prototype targetlheat-sink system subjected to primary ion beam irradiation will be presented in this report.
Date:
October 5, 1999
Creator:
Alton, G. D. & Liu, Y.
Object Type:
Article
System:
The UNT Digital Library
Medium Energy Measurements of N-N Parameters. Final technical report
None
Date:
October 1, 1999
Creator:
Ambrose, David; Coffey, Patrick; Glass, George; McNaughton, Kok Hoeng; Riley, Peter & Tang, Jaw-Luen
Object Type:
Report
System:
The UNT Digital Library
Southwest Retort, Volume [52], Number 2, October 1999
This publication of the Dallas-Fort Worth Section of the American Chemical Society includes information about research, prominent scientist, organizational business, and various other stories of interest to the community.
Date:
October 1999
Creator:
American Chemical Society. Dallas/Fort Worth Section.
Object Type:
Journal/Magazine/Newsletter
System:
The UNT Digital Library
Thermoacoustic Liquefaction of Coal Mine Methane to Produce Lng for Heavy Vehicle Applicaitons
This report describes the activity undertaken by the project members under MORGANTOWN ENERGY TECHNOLOGY CENTER (METC) contract No. DE-AC21-95MC32185 to develop a project that will provide a commercial use for Coal Mine Methane (CMM). In particular, the report describes a project to convert CMM into Liquefied Natural Gas (LNG) and to market that LNG to the transportation sector in and around the I-79 corridor near Morgantown, West Virginia. The report discusses the sources of CMM and provides estimates of the extent of the resource specifically dedicated to the project. It discusses the novel refrigeration technology that will be employed to convert the CMM to LNG and the gas conditioning technology that will be used to bring the raw CMM up to cryogenic processing specifications. Summary capital and operating cost estimates are furnished for the project and specific monetary and schedule requirements are identified so the project can be examined in its entirety. The report discusses the immediate market potential for the successful commercial sale of LNG into the nearby market and provides estimates of future market penetration into local, regional and wider markets. Lastly, the report comments on the environmental effects of the project and extrapolates these benefits to future …
Date:
October 29, 1999
Creator:
Aminian, Kashi; English, Lloyd; Patchen, Douglas; Siriwardane, Hema; Estes, Charles D. & Zahradnik, Raymond L.
Object Type:
Report
System:
The UNT Digital Library
CdZnTe Material Uniformity and Coplanar-Grid Gamma-Ray Detector Performance
None
Date:
October 1, 1999
Creator:
Amman, M.; Luke, P. N. & Lee, J. S.
Object Type:
Article
System:
The UNT Digital Library
Development and Design of a User Interface for a Computer Automated Heating, Ventilation, and Air Conditioning System
A user interface is created to monitor and operate the heating, ventilation, and air conditioning system. The interface is networked to the system's programmable logic controller. The controller maintains automated control of the system. The user through the interface is able to see the status of the system and override or adjust the automatic control features. The interface is programmed to show digital readouts of system equipment as well as visual queues of system operational statuses. It also provides information for system design and component interaction. The interface is made easier to read by simple designs, color coordination, and graphics. Fermi National Accelerator Laboratory (Fermi lab) conducts high energy particle physics research. Part of this research involves collision experiments with protons, and anti-protons. These interactions are contained within one of two massive detectors along Fermilab's largest particle accelerator the Tevatron. The D-Zero Assembly Building houses one of these detectors. At this time detector systems are being upgraded for a second experiment run, titled Run II. Unlike the previous run, systems at D-Zero must be computer automated so operators do not have to continually monitor and adjust these systems during the run. Human intervention should only be necessary for system start …
Date:
October 8, 1999
Creator:
Anderson, B.
Object Type:
Report
System:
The UNT Digital Library
Detection of Volatile Organics Using a Surface Acoustic Wave Array System
A chemical sensing system based on arrays of surface acoustic wave (SAW) delay lines has been developed for identification and quantification of volatile organic compounds (VOCs). The individual SAW chemical sensors consist of interdigital transducers patterned on the surface of an ST-cut quartz substrate to launch and detect the acoustic waves and a thin film coating in the SAW propagation path to perturb the acoustic wave velocity and attenuation during analyte sorption. A diverse set of material coatings gives the sensor arrays a degree of chemical sensitivity and selectivity. Materials examined for sensor application include the alkanethiol-based self-assembled monolayer, plasma-processed films, custom-synthesized conventional polymers, dendrimeric polymers, molecular recognition materials, electroplated metal thin films, and porous metal oxides. All of these materials target a specific chemical fi.mctionality and the enhancement of accessible film surface area. Since no one coating provides absolute analyte specificity, the array responses are further analyzed using a visual-empirical region-of-influence (VERI) pattern recognition algorithm. The chemical sensing system consists of a seven-element SAW array with accompanying drive and control electronics, sensor signal acquisition electronics, environmental vapor sampling hardware, and a notebook computer. Based on data gathered for individual sensor responses, greater than 93%-accurate identification can be achieved for …
Date:
October 14, 1999
Creator:
Anderson, Lawrence F.; Bartholomew, John W.; Cernosek, Richard W.; Colburn, Christopher W.; Crooks, R. M.; Martinez, R. F. et al.
Object Type:
Article
System:
The UNT Digital Library