Search Results

open access

An 8-Step Program: Shaping and Fixed-Time Food Delivery Effects on Several Approximations and Undesired Responses in Goats.

Description: This study investigated the effects of a shaping program for halter training across 8 steps in the program and 4 trial-terminating, or "undesirable," responses. Three La Mancha goats (Capra hircus) located at the Frank Buck Zoo in Gainesville, Texas were used for the study. A fixed-time 15 s (FT-15 s) was used during the baseline conditions, to examine the effects of response contingent and response-independent food deliveries, as well as to examine what preliminary steps might not necessarily have to be shaped. All 3 goats successfully learned to allow the halter to be placed on them and to lead on the halter, although 2 of the 3 goats required an additional task analysis for the fifth step to further break down that approximation. Several of the early steps selected by the researchers were not necessary to complete the program, as determined by the baseline condition.
Date: May 2003
Creator: Fernandez, Eduardo J.
Partner: UNT Libraries
open access

A 201 MHz RF cavity design with non-stressed pre-curved Be windows for muon cooling channels

Description: We present a 201-MHz RF cavity design for muon cooling channels with non-stressed and pre-curved Be foils to terminate the beam apertures. The Be foils are necessary to improve the cavity shunt impedance with large beam apertures needed for accommodating large transverse size muon beams. Be is a low-Z material with good electrical and thermal properties. It presents an almost transparent window to muon beams, but terminates the RF cavity electro-magnetically. Previous designs use pre-stressed flat Be foils in order to keep cavity from detuning resulted from RF heating on the window surface. Be foils are expensive, and it is difficult to make them under desired tension. An alternative design is to use precurved and non-stressed Be foils where the buckling direction is known, and frequency shifts can be properly predicted. We will present mechanical simulations on the Be foils in this paper.
Date: May 1, 2003
Creator: Li, Derun; Ladran, A.; Staples, J.; Virostek, S.; Zisman, M.; Lau, W. et al.
Partner: UNT Libraries Government Documents Department
open access

An Abstract Description Approach to the Discovery and Classification of Bioinformatics Web Sources

Description: The World Wide Web provides an incredible resource to genomics researchers in the form of dynamic data sources--e.g. BLAST sequence homology search interfaces. The growth rate of these sources outpaces the speed at which they can be manually classified, meaning that the available data is not being utilized to its full potential. Existing research has not addressed the problems of automatically locating, classifying, and integrating classes of bioinformatics data sources. This paper presents an overview of a system for finding classes of bioinformatics data sources and integrating them behind a unified interface. We examine an approach to classifying these sources automatically that relies on an abstract description format: the service class description. This format allows a domain expert to describe the important features of an entire class of services without tying that description to any particular Web source. We present the features of this description format in the context of BLAST sources to show how the service class description relates to Web sources that are being described. We then show how a service class description can be used to classify an arbitrary Web source to determine if that source is an instance of the described service. To validate the effectiveness of this approach, we have constructed a prototype that can correctly classify approximately two-thirds of the BLAST sources we tested. We then examine these results, consider the factors that affect correct automatic classification, and discuss future work.
Date: May 1, 2003
Creator: Rocco, D & Critchlow, T J
Partner: UNT Libraries Government Documents Department
open access

Accelerated Stress Testing of Thin-Film Modules with SnO2:F Transparent Conductors

Description: This paper reviews a testing program conducted at NREL for the past two years that applied voltage, water vapor, and light stresses to thin-film photovoltaic (PV) modules with SnO2:F transparent conducting oxides (TCOs) deposited on soda-lime glass superstrates. Electrochemical corrosion at the glass-TCO interface was observed to result in delamination of the thin-film layers. Experimental testing was directed toward accelerating the corrosion and understanding the nature of the resulting damage.
Date: May 1, 2003
Creator: Osterwald, C. R.; McMahon, T. J.; del Cueto, J. A.; Adelstein, J. & Puett, J.
Partner: UNT Libraries Government Documents Department
open access

Accelerator Magnet Plugging By Metal Oxides: A Theoretical Investigation, Remediation, and Preliminary Results

Description: The Thomas Jefferson National Accelerator Facility has experienced magnet overheating at high power. Overheating is caused by cooling water passages becoming plugged and is a direct result of the Dean Effect deposition of corrosion products suspended in the water. Salving simplified dynamic model equations of the flow in the magnet tubing bends yielded a relationship for plugging rate as a function of particle size, concentration, velocity, channel width and bend radius. Calculated deposition rates using data from a previous study are promising. Remediation has consisted of submicron filtration, magnet cleaning, and dissolved oxygen removal. Preliminary results are good: no accelerator outages have been attributed to magnet plugging since the remediation has been completed.
Date: May 1, 2003
Creator: Rust, William W.
Partner: UNT Libraries Government Documents Department
open access

Accessing Information on the World Wide Web: Predicting Usage Based on Involvement

Description: Advice for Web designers often includes an admonition to use short, scannable, bullet-pointed text, reflecting the common belief that browsing the Web most often involves scanning rather than reading. Literature from several disciplines focuses on the myriad combinations of factors related to online reading but studies of the users' interests and motivations appear to offer a more promising avenue for understanding how users utilize information on Web pages. This study utilized the modified Personal Involvement Inventory (PII), a ten-item instrument used primarily in the marketing and advertising fields, to measure interest and motivation toward a topic presented on the Web. Two sites were constructed from Reader's Digest Association, Inc. online articles and a program written to track students' use of the site. Behavior was measured by the initial choice of short versus longer versions of the main page, the number of pages visited and the amount of time spent on the site. Data were gathered from students at a small, private university in the southwest part of the United States to answer six hypotheses which posited that subjects with higher involvement in a topic presented on the Web and a more positive attitude toward the Web would tend to select the longer text version, visit more pages, and spend more time on the site. While attitude toward the Web did not correlate significantly with any of the behavioral factors, the level of involvement was associated with the use of the sites in two of three hypotheses, but only partially in the manner hypothesized. Increased involvement with a Web topic did correlate with the choice of a longer, more detailed initial Web page, but was inversely related to the number of pages viewed so that the higher the involvement, the fewer pages visited. An additional indicator of usage, the average amount …
Date: May 2003
Creator: Langford, James David
Partner: UNT Libraries
open access

Acculturative Processes and Their Impact on Self-Reports of Psychological Distress in Mexican-American Adolescents

Description: The current study examined the effects of acculturative processes on the self-report of behavioral problems in Hispanic children ages 11-14. Acculturation was measured by the Acculturation Rating Scale for Mexican Americans-II (ARSMA-II) (ã Sage Publications, Thousand Oaks, CA, www.sagepub.com) (Cuellar, Arnold, and Maldonado, 1995) and the self-report of behavioral symptoms was assessed using the Youth Self-Report (ã T.M. Achenbach, Burlington, VT, www.aseba.com) (Achenbach, 1991). It was hypothesized that while both the linear and orthogonal categories of acculturation would account for a significant proportion of the variance in behavior problems in this age group, the orthogonal model would account for a larger proportion of variance due to its multidimensional nature. As well, it was hypothesized that the experimental Marginalization scales of the ARSMA-II would be predictive of behavioral problems. Multivariate analysis of variance was used to test these hypotheses and results were non-significant for the linear, orthogonal, and marginalization categories. The effects of the ethnic/cultural homogeneity of the region from which the sample was drawn, the buffering of social support, and the developmental aspects of ethnic identity are discussed as factors which may have influenced the potential impact of acculturative stress on psychological and behavioral functioning.
Date: May 2003
Creator: Garrison, Lance A.
Partner: UNT Libraries
open access

ACME: Algorithms for Contact in a Multiphysics Environment API Version 1.3

Description: An effort is underway at Sandia National Laboratories to develop a library of algorithms to search for potential interactions between surfaces represented by analytic and discretized topological entities. This effort is also developing algorithms to determine forces due to these interactions for transient dynamics applications. This document describes the Application Programming Interface (API) for the ACME (Algorithms for Contact in a Multiphysics Environment) library.
Date: May 1, 2003
Creator: BROWN, KEVIN H.; VOTH, THOMAS E.; GLASS, MICHEAL W.; GULLERUD, ARNE S.; HEINSTEIN, MARTIN W. & JONES, REESE E.
Partner: UNT Libraries Government Documents Department
open access

Adhesion Strength Study of EVA Encapsulants on Glass Substrates

Description: An extensive peel-test study was conducted to investigate the various factors that may affect the adhesion strength of photovoltaic module encapsulants, primarily ethylene-vinyl acetate (EVA), on glass substrates of various laminates based on a common configuration of glass/encapsulant/backfoil. The results show that"pure" or"absolute" adhesion strength of EVA-to-glass was very difficult to obtain because of tensile deformation of the soft, semi-elastic EVA layer upon pulling. A mechanically"strong enough" backing foil on the EVA was critical to achieving the"apparent" adhesion strength. Peel test method with a 90-degree-pull yielded similar results to a 180-degree-pull. The 90-degree-pull method better revealed the four stages of delamination failure of the EVA/backfoil layers. The adhesion strength is affected by a number of factors, which include EVA type, formulation, backfoil type and manufacturing source, glass type, and surface priming treatment on the glass surface or on the backfoil. Effects of the glass-cleaning method and surface texture are not obvious. Direct priming treatments used in the work did not improve, or even worsened, the adhesion. Aging of EVA by storage over~5 years reduced notably the adhesion strength. Lower adhesion strengths were observed for the blank (unformulated) EVA and non-EVA copolymers, such as poly(ethylene-co-methacrylate) (PEMA) or poly(ethylene-co-butylacrylate) (PEBA). Their adhesion strengths increased if the copolymers were cross-linked. Transparent fluoropolymer superstrates such as TefzelTM and DureflexTM films used for thin-film PV modules showed low adhesion strengths to the EVA at a level of~2 N/mm.
Date: May 1, 2003
Creator: Pern, F. J. & Glick, S. H.
Partner: UNT Libraries Government Documents Department
open access

Advanced CIGS Photovoltaic Technology: Annual Technical Report, 15 November 2001-14 November 2002

Description: Energy Photovoltaics, Inc. (EPV) has consistently pursued a vacuum-based approach to CIGS production, using novel linear-source technology and standard soda-lime glass substrates. It has also chosen to develop processing methods with worker safety in mind. These choices result in layers having controllable purity and low physical defects, and production without significant hazards. Considerations such as these are important in helping to minimize the processing costs of CIGS. Technically, thin-film PV technologies have advanced considerably in the last few years. EPV successfully produced high-quality 0.43m2 Mo-coated glass substrates that, when cut, enabled NREL to produce 17.1% CIGS cells on such substrates. EPV successfully used novel linear evaporative sources for supply of Cu, In, Ga, and Se to form CIGS on 0.43m2 substrates, producing modules with Voc's of up to 37 V. A new approach to buffer-layer deposition was pioneered through synthesis of the compound ZnIn2Se4 and its use as a source material. In addition, the current generated in exploratory a-Si/a-Si/CIGS stacked devices was increased from 6 to 13 mA/cm2. Supporting these programs, EPV's upgraded analytical laboratories provided rapid in-house feedback concerning material and device properties. The objective of this subcontract is to develop and assemble the various pieces of new technology that EPV considers essential for cost-effective production of CIGS modules. The long-term objective of the Thin Film PV Partnership Program is to demonstrate low-cost, reproducible modules of 15% aperture-area efficiency.
Date: May 1, 2003
Creator: Delahoy, A. E. & Chen, L.
Partner: UNT Libraries Government Documents Department
open access

Advanced Concepts for Photovoltaic Cells

Description: Novel approaches to high efficiency photovoltaic cells are discussed that are based on the use of semiconductor quantum dots to slow hot electron cooling and thus produce either enhanced photocurrents through impact ionization or enhanced photovoltages through hot electron transport and collection.
Date: May 1, 2003
Creator: Nozik, A. J.
Partner: UNT Libraries Government Documents Department
open access

ADVANCED GAS TURBINE SYSTEMS RESEARCH PROGRAM

Description: The activities of the Advanced Gas Turbine Systems Research (AGTSR) program for the reporting period October 1, 2002 to December 31, 2002 are described in this quarterly report. No new membership, workshops, research projects, internships, faculty fellowships or special studies were initiated during this reporting period. Contract completion is set for June 30, 2003. During the report period, six research progress reports were received (3 final reports and 3 semi-annual reports). The University of Central Florida contract SR080 was terminated during this period, as UCF was unable to secure research facilities. AGTSR now projects that it will under spend DOE obligated funds by approximately 340-350K$.
Date: May 1, 2003
Creator: Golan, Lawrence P.
Partner: UNT Libraries Government Documents Department
open access

ADVANCED GAS TURBINE SYSTEMS RESEARCH PROGRAM

Description: The quarterly activities of the Advanced Gas Turbine Systems Research (AGTSR) program are described in this quarterly report. As this program administers research, we have included all program activity herein within the past quarter as dated. More specific research progress reports are provided weekly at the request of the AGTSR COR and are being sent to NETL As for the administration of this program, items worthy of note are presented in extended bullet format following the appropriate heading. No new memberships, workshops, research projects, internships, faculty fellowships or special studies were initiated during this reporting period. Contract completion is set for June 30, 2003. During the report period, nine subcontractor reports were received (5 final reports and 4 semi-annual reports). The report technology distribution is as follows: 3--aero-heat transfer, 2--combustion and 4--materials. AGTSR continues to project that it will under spend DOE obligated funds by approximately $329K.
Date: May 1, 2003
Creator: Golan, Lawrence P.
Partner: UNT Libraries Government Documents Department
open access

Advanced NDE Technologies for Powder Metal Components

Description: Nondestructive evaluation encompasses numerous technologies that assess materials and determine important properties. This paper demonstrates the applicability of several of these technologies to the field of powder metallurgy. The usual application of nondestructive evaluation is to detect and quantify defects in fully sintered product. But probably its most appealing role is to sense problems earlier in the manufacturing process to avoid making defects at all. Also nondestructive evaluation can be incorporated into the manufacturing processes to monitor important parameters and control the processes to produce defect free product. Nondestructive evaluation can characterize powders, evaluate components in the green state, monitor the sintering process, and inspect the final component.
Date: May 1, 2003
Creator: Martin, P; Haskins, J; Thomas, G & Dolan, K
Partner: UNT Libraries Government Documents Department
open access

ADVANCED RADIATION THEORY SUPPORT ANNUAL REPORT 2002, FINAL REPORT

Description: Z-PINCH PHYSICS RADIATION FROM WIRE ARRAYS. This report describes the theory support of DTRA's Plasma Radiation Source (PRS) program carried out by NRL's Radiation Hydrodynamics Branch (Code 6720) in FY 2002. Included is work called for in DTRA MIPR 02-2045M - ''Plasma Radiation Theory Support'' and in DOE's Interagency Agreement DE-AI03-02SF22562 - ''Spectroscopic and Plasma Theory Support for Sandia National Laboratories High Energy Density Physics Campaign''. Some of this year's work was presented at the Dense Z-Pinches 5th International Conference held June 23-28 in Albuquerque, New Mexico. A common theme of many of these presentations was a demonstration of the importance of correctly treating the radiation physics for simulating Plasma Radiation Source (PRS) load behavior and diagnosing load properties, e.g, stagnation temperatures and densities. These presentations are published in the AIP Conference Proceedings and, for reference, they are included in Section 1 of this report. Rather than describe each of these papers in the Executive Summary, they refer to the abstracts that accompany each paper. As a testament to the level of involvement and expertise that the Branch brings to DTRA as well as the general Z-Pinch community, eight first-authored presentations were contributed at this conference as well as a Plenary and an Invited Talk. The remaining four sections of this report discuss subjects either not presented at the conference or requiring more space than allotted in the Proceedings.
Date: May 1, 2003
Creator: Davis, J.; Apruzese, J; Chong, Y.; Clark, R.; Dasgupta, A.; Giuliani, J. et al.
Partner: UNT Libraries Government Documents Department
open access

Agent-Based Architecture for Web Deployment of Multi-Agents as Conversational Interfaces.

Description: Agent-based architecture explains the rationale and basis for developing agents that can interact with users through natural language query/answer patterns developed systematically using AIML (artificial intelligence mark-up language) scripts. This thesis research document also explains the architecture for VISTA (virtual interactive story-telling agents), which is used for interactive querying in educational and recreational purposes. Agents are very effective as conversational interfaces when used along side with graphical user interface (GUI) in applications and Web pages. This architecture platform can support multiple agents with or with out sharing of knowledgebase. They are very useful as chat robots for recreational purposes, customer service and educational purposes. This platform is powered by Java servlet implementation of Program D and contained in Apache Tomcat server. The AIML scripting language defined here in is a generic form of XML language and forms the knowledgebase of the bot. Animation is provided with Microsoft® Agent technology and text-to-speech support engine.
Date: May 2003
Creator: Pothuru, Ranjit Kumar
Partner: UNT Libraries
open access

Amorphous and Thin-Film Silicon

Description: This paper outlines the key concepts set forth in the Amorphous and Thin-Film Silicon session at the National Center for Photovoltaics and Solar Program Review Meeting held March 26, 2003 in Denver, Colorado. Key elements of discussion centered around benchmarking the NREL/NCPV amorphous and thin-film silicon program, identifying holes in the scientific understanding of these materials and devices, identifying hurdles to large scale manufacturing, and what direction the program should take for future activities.
Date: May 1, 2003
Creator: Nelson, B. P.; Atwater, H. A.; von Roedern, B.; Yang, J.; Sims, P.; Deng, X. et al.
Partner: UNT Libraries Government Documents Department
open access

Analysis of a grid window structure for RF cavities in a Muon cooling channel

Description: We report on the electromagnetic and thermal analysis of a grid window structure for high gradient, low frequency RF cavities. Windows may be utilized to close the beam iris and increase shunt impedance of closed-cell RF cavities. This work complements previous work presented for windows made of solid beryllium foil. An electromagnetic and thermal analysis of the thin wall tubes in a grid pattern was conducted using both MAFIA4 and ANSYS finite element analyses. The results from both codes agreed well for a variety of grid configurations and spacing. The grid configuration where the crossing tubes touched was found to have acceptable E-Fields and H-Fields performance. The thermal profiles for the grid will also be shown to determine a viable cooling profile.
Date: May 1, 2003
Creator: Ladran, A.; Li, D.; Moretti, A.; Rimmer, R.; Staples, J.; Virostek, S. et al.
Partner: UNT Libraries Government Documents Department
open access

Analysis of Japanese Exports and Imports of Rice

Description: This research shows that the Japanese rice policy has affected the volume of exported and imported rice; moreover, multilateral and bilateral agreements have also affected Japanese rice policy. Japan's institution of subsidies and trade barriers has made its rice products too expensive for foreign trade and its domestic consumers. Since the WTO agreement has forced Japan to open its market gradually over six years, Japan may be unable to compete internationally because of its limited land, high labor costs, and the field utility fees.
Date: May 2003
Creator: Shiraiwa, Toshio
Partner: UNT Libraries
open access

Analysis of the Massive Salt Fall in Big Hill Cavern 103

Description: This report summarizes recent reviews, observations, and analyses believed to be imperative to our understanding of the recent two million cubic feet salt fall event in Big Hill Cavern 103, one of the caverns of the Strategic Petroleum Reserve (SPR). The fall was the result of one or more stress driven mechanical instabilities, the origins of which are discussed in the report. The work has lead to important conclusions concerning the engineering and operations of the caverns at Big Hill. Specifically, Big Hill, being the youngest SPR site, was subjected to state-of-the-art solutioning methods to develop nominally well-formed, right-circular cylindrical caverns. Examination of the pressure history records indicate that operationally all Big Hill SPR caverns have been treated similarly. Significantly, new three-dimensional (3-D) imaging methods, applied to old (original) and more recent sonar survey data, have provided much more detailed views of cavern walls, roofs, and floors. This has made possible documentation of the presence of localized deviations from ''smooth'' cylindrical cavern walls. These deviations are now recognized as isolated, linear and/or planar features in the original sonar data (circa early 1990s), which persist to the present time. These elements represent either sites of preferential leaching, localized spalling, or a combination of the two. Understanding the precise origin of these phenomena remains a challenge, especially considering, in a historical sense, the domal salt at Big Hill was believed to be well-characterized. However, significant inhomogeneities in the domal salt that may imply abnormalities in leaching were not noted. Indeed, any inhomogeneities were judged inconsequential to the solution-engineering methods at the time, and, by the same token, to the approaches to modeling the rock mass geomechanical response. The rock mass was treated as isotropic and homogeneous, which in retrospect, appears to have been an over simplification. This analysis shows there are possible …
Date: May 1, 2003
Creator: MUNSON, DARRELL E.; BAUER, STEPHEN J.; RAUTMAN, CHRISTOPHER A.; EHGARTNER, BRIAN L. & SATTLER, ALLAN R.
Partner: UNT Libraries Government Documents Department
open access

Analytical study of envelope modes for a fully depressed beam in solenoidal and quadrupole periodic transport channels

Description: We present an analysis of envelope perturbations evolving in the limit of a fully space-charge depressed (zero emittance) beam in periodic, thin-lens focusing channels. Both periodic solenoidal and FODO quadrupole focusing channels are analyzed. The phase advance and growth rate of normal mode perturbations are analytically calculated as a function of the undepressed particle phase advance to characterize the evolution of envelope perturbations.
Date: May 2003
Creator: Bukh, Boris & Lund, Steven M.
Partner: UNT Libraries Government Documents Department
open access

Application of High-Temperature Mold Materials to Die Cast Copper Motor Rotor for Improved Efficiency

Description: The objective of the study, Application of High-Temperature Mold Materials to Die Cast Copper Motor Rotor for Improved Efficiency, was to support the Copper Development Association (CDA) in its effort to design, fabricate and demonstrate mold technologies designed to withstand the copper motor rotor die casting environment for an economically acceptable life. The anticipated result from the compiled data and tests were to: (1) identify materials suitable for die casting copper, (2) fabricate motor rotor molds and (3) supply copper rotor motors for testing in actual compressor systems. Compressor manufacturers can apply the results to assess the technical and economical viability of copper rotor motors.
Date: May 1, 2003
Creator: Cowie, John G.; Edwin F. Brush, Jr.; Peters, Dale T.; Midson, Stephen P. & Son, Darryl J. Van
Partner: UNT Libraries Government Documents Department
Back to Top of Screen