Collection
Office of Scientific & Technical Information Technical Reports
22,567
Congressional Research Service Reports
3,663
Texas Laws and Resolutions Archive
3,144
Technical Report Archive and Image Library
2,237
Texas Patents
1,673
Texas Attorney General Opinions
1,440
Texas State Publications
1,436
Government Accountability Office Reports
1,304
National Advisory Committee for Aeronautics Collection
1,074
Defense Base Closure and Realignment Commission
435
29 More
Serial/Series Title
Degree Department
Country
States
Decade
Month
38,804 Matching Results
Results open in a new window/tab.
Results:
1 - 24 of
38,804
next
Empirical Study of Ne in H-Mode Pedestal in DIII-D
There is compelling empirical [1] and theoretical [2] evidence that the global confinement of H-mode discharges increases as the pedestal pressure or temperature increases. Therefore, confidence in the performance of future machines requires an ability to predict the pedestal conditions in those machines. At this time, both the theoretical and empirical understanding of transport in the pedestal are incomplete and are inadequate to predict pedestal conditions in present or future machines. Recent empirical results might be evidence of a fundamental relation between the electron temperature T{sub e} and electron density n{sub e} profiles in the pedestal. A data set from the ASDEX-Upgrade tokamak has shown that {eta}{sub e}, the ratio between the scale lengths of the n{sub e} and T{sub e} profiles, exhibits a value of about 2 throughout the pedestal, despite a large range of the actual density and temperature values [3]. Data from the DIII-D tokamak show that over a wide range of pedestal density, the width of the steep gradient region for the T{sub e} profile is about 1-2 times the corresponding width for the n{sub e} profile, where both widths are measured from the plasma edge [4]. Thus, the barrier in the density might form a …
Date:
May 5, 2005
Creator:
. Groebner, R. J.; Osborne, T. H.; Fenstermacher, M. E.; Leonard, A. W.; Mahdavi, M. A.; Snyder, P. B. et al.
Object Type:
Article
System:
The UNT Digital Library
Cost-Effective Silicon Wafers for Solar Cells
Advanced Research Projects Agency-Energy project sheet summarizing general information about a new program for hydrogen fuel cell vehicles (project title "Direct Wafer Enabling Terawatt Photovoltaics") including critical needs, innovation and advantages, impacts, and contact information. This sheet is the first open solicitation, announcing funding opportunities for involvement in the project.
Date:
May 11, 2012
Creator:
1366 Technologies, Inc.
Object Type:
Text
System:
The UNT Digital Library
Local Effects of Biased Electrodes in the Divertor of NSTX
The goal of this paper is to characterize the effects of small non-axisymmetric divertor plate electrodes on the local scrape-off layer plasma. Four small rectangular electrodes were installed into the outer divertor plates of NSTX. When the electrodes were located near the outer divertor strike point and biased positively, there was an increase in the nearby probe currents and probe potentials and an increase in the LiI light emission at the large major radius end of these electrodes. When an electrode located farther outward from the outer divertor strike point was biased positively, there was sometimes a significant decrease in the LiI light emission at the small major radius end of this electrode, but there were no clear effects on the nearby probes. No non-local effects were observed with the biasing of these electrodes.
Date:
May 7, 2012
Creator:
: S. Zweben, M.D. Campanell, B.C. Lyons, R.J. Maqueda, Y. Raitses, A.L. Roquemore and F. Scotti
Object Type:
Report
System:
The UNT Digital Library
Epicyclic Twin-helix Magnetic Structure for Parametric-resonance Ionization Cooling
Parametric-resonance Ionization Cooling (PIC) is envisioned as the final 6D cooling stage of a high-luminosity muon collider. Implementing PIC imposes stringent constraints on the cooling channel's magnetic optics design. This paper presents a linear optics solution compatible with PIC. Our solution consists of a superposition of two opposite-helicity equal-period and equal-strength helical dipole harmonics and a straight normal quadrupole. We demonstrate that such a system can be adjusted to meet all of the PIC linear optics requirements while retaining large acceptance.
Date:
May 1, 2010
Creator:
A. Afanasev, R.P. Johnson, Y.S. Derbenev, V.S. Morozov
Object Type:
Article
System:
The UNT Digital Library
Analysis of Vernier Scans during the PP2PP run in 2009 (pp at 100 GeV/beam)
N/A
Date:
May 1, 2012
Creator:
A., Drees
Object Type:
Report
System:
The UNT Digital Library
Semi-analytical description of the modular section of the coherent electron cooling via integral transforms
N/A
Date:
May 12, 2013
Creator:
A., Elizarov & Litvinenko, V.
Object Type:
Article
System:
The UNT Digital Library
Shielding of a hadron in a finite e-beam
The thorough study of coherent electron cooling, the modern cooling technique capable to deal with accelerators operating in the range of few TeVs, rises many interesting questions. One of them is a shielding dynamics of a hadron in an electron beam. Now this effect is computed analytically in the infinite beam approximation. Many effects are drastically different in finite and infinite plasmas. Here we propose a method to compute the dynamical shielding effect in a finite cylindrical plasma - the realistic model of an electron beam in accelerators.
Date:
May 20, 2012
Creator:
A., Elizarov; Litvinenko, V. & Wang, G.
Object Type:
Article
System:
The UNT Digital Library
Towards demonstration of electron cooling with bunched electron beam
N/A
Date:
May 1, 2012
Creator:
A., Fedotov
Object Type:
Report
System:
The UNT Digital Library
Device and technique for in-situ coating of the RHIC cold bore vacuum tubes with thick OFHC
N/A
Date:
May 12, 2013
Creator:
A., Hershcovitch; Blaskiewicz, M.; Brennan, J. M.; Chawla, A.; Custer, A.; Erickson, M. et al.
Object Type:
Article
System:
The UNT Digital Library
Spherical Aberration Corrections for an Electrostatic Gridded Lens
N/A
Date:
May 1, 2008
Creator:
A., Pikin
Object Type:
Report
System:
The UNT Digital Library
Optics modification of the electron collector for the Relativistic Heavy Ion Collider Electron Beam Ion Source
N/A
Date:
May 1, 2012
Creator:
A., Pikin; Alessi, J.G.; Beebe, E.N.; Raparia, D. & Snydstrup, L.
Object Type:
Report
System:
The UNT Digital Library
Optics modification of the electron collector for the Relativistic Heavy Ion Collider Electron Beam Ion Source
N/A
Date:
May 1, 2012
Creator:
A., Pikin; Alessi, J.G.; Beebe, E.N.; Raparia, D. & Snydstrup, L.
Object Type:
Report
System:
The UNT Digital Library
ELSHIM: Program to Simulate Elastic Processes of Heavy Ions
None
Date:
May 1, 1992
Creator:
A., Van Ginneken
Object Type:
Report
System:
The UNT Digital Library
Systematics of Fission-Product Yields
None
Date:
May 5, 2002
Creator:
A.C.Wahl
Object Type:
Report
System:
The UNT Digital Library
Progress of Bep Treatments on Nb at JLAB
Recent experimental results have indicated that Buffered Electropolishing (BEP) is a promising candidate for the next generation of surface treatment technique for Nb superconducting radio frequency (SRF) cavities to be used in particle accelerators. In order to lay the foundation for using BEP as the next generation surface treatment technique for Nb SRF cavities, some fundamental aspects of BEP treatments for Nb have to be investigated. In this report, recent progress on BEP study at JLab is shown. Improvements on the existing vertical BEP are made to allow water cooling from outside of a Nb single cell cavity in addition to cooling provided by acid circulation so that the temperature of the cavity can be stable during processing. Some investigation on the electrolyte mixture was performed to check the aging effect of the electrolyte. It is shown that good polishing results can still be obtained on Nb at a current density of 171 mA/cm when the BEP electrolyte was at the stationary condition and was more than 1.5 years old.
Date:
May 1, 2010
Creator:
A.T. Wu, S. Jin, R.A. Rimmer,X.Y. Lu, K. Zhao
Object Type:
Article
System:
The UNT Digital Library
Can Data Recognize Its Parent Distribution?
This study is concerned with model selection of lifetime and survival distributions arising in engineering reliability or in the medical sciences. We compare various distributions, including the gamma, Weibull and lognormal, with a new distribution called geometric extreme exponential. Except for the lognormal distribution, the other three distributions all have the exponential distribution as special cases. A Monte Carlo simulation was performed to determine sample sizes for which survival distributions can distinguish data generated by their own families. Two methods for decision are by maximum likelihood and by Kolmogorov distance. Neither method is uniformly best. The probability of correct selection with more than one alternative shows some surprising results when the choices are close to the exponential distribution.
Date:
May 1, 1999
Creator:
A.W.Marshall; J.C.Meza & Olkin, and I.
Object Type:
Report
System:
The UNT Digital Library
[Project Summary: Deepwater Program: The Technology and Economics of Deepwater Production Projects]
Report summary describing the work completed at ABS Group, Inc. for 'Deepwater Program: The Technology and Economics of Deepwater Production Projects'. It includes background information on the project funding and sponsorship, goals, methodology, and findings.
Date:
May 2004
Creator:
ABS Group, Inc.
Object Type:
Text
System:
The UNT Digital Library
Microstructure, Phase Formation, and Stress of Reactively-Deposited Metal Hydride Thin Films
This document summarizes research of reactively deposited metal hydride thin films and their properties. Reactive deposition processes are of interest, because desired stoichiometric phases are created in a one-step process. In general, this allows for better control of film stress compared with two-step processes that react hydrogen with pre-deposited metal films. Films grown by reactive methods potentially have improved mechanical integrity, performance and aging characteristics. The two reactive deposition techniques described in this report are reactive sputter deposition and reactive deposition involving electron-beam evaporation. Erbium hydride thin films are the main focus of this work. ErH{sub x} films are grown by ion beam sputtering erbium in the presence of hydrogen. Substrates include a Al{sub 2}O{sub 3} {l_brace}0001{r_brace}, a Al{sub 2}O{sub 3} {l_brace}1120{r_brace}, Si{l_brace}001{r_brace} having a native oxide, and polycrystalline molybdenum substrates. Scandium dideuteride films are also studied. ScD{sub x} is grown by evaporating scandium in the presence of molecular deuterium. Substrates used for scandium deuteride growth include single crystal sapphire and molybdenum-alumina cermet. Ultra-high vacuum methods are employed in all experiments to ensure the growth of high purity films, because both erbium and scandium have a strong affinity for oxygen. Film microstructure, phase, composition and stress are evaluated using a …
Date:
May 1, 2002
Creator:
ADAMS, DAVID P.; ROMERO, JUAN A.; RODRIGUEZ, MARK A.; FLORO, JERROLD A. & KOTULA, PAUL G.
Object Type:
Report
System:
The UNT Digital Library
Representative volume size: A comparison of statistical continuum mechanics and statistical physics
In this combination background and position paper, the authors argue that careful work is needed to develop accurate methods for relating the results of fine-scale numerical simulations of material processes to meaningful values of macroscopic properties for use in constitutive models suitable for finite element solid mechanics simulations. To provide a definite context for this discussion, the problem is couched in terms of the lack of general objective criteria for identifying the size of the representative volume (RV) of a material. The objective of this report is to lay out at least the beginnings of an approach for applying results and methods from statistical physics to develop concepts and tools necessary for determining the RV size, as well as alternatives to RV volume-averaging for situations in which the RV is unmanageably large. The background necessary to understand the pertinent issues and statistical physics concepts is presented.
Date:
May 1, 1999
Creator:
AIDUN,JOHN B.; TRUCANO,TIMOTHY G.; LO,CHI S. & FYE,RICHARD M.
Object Type:
Report
System:
The UNT Digital Library
Molecular dynamic simulations, {sup 6}Li solid state NMR and ultraphosphate glasses
The author's laboratory continues to use NMR to investigate the structure and dynamics in amorphous materials, including the local structure of ultraphosphate glasses. Changes in the alkali environment in these phosphate glasses as a function of modifier concentration has recently been probed using {sup 6}Li and {sup 23}Na solid state NMR. Molecular dynamic (MD) simulations have also been performed in an attempt to gain additional insight into the variations of the local structure. Interestingly, although there are distinct variations in the Li coordination number as well as the Li-O bond lengths in the MD simulations (with a minimum or maximum in these parameters near the 20% Li{sub 2}O concentration), a linear change in the {sup 6}Li NMR chemical shift is observed between 5 and 50% Li{sub 2}O mole fraction. One would expect that such variations should be observable in the NMR chemical shift. In an attempt to understand this behavior the author has performed empirical calculation of the {sup 6}Li NMR chemical shift directly from the structures obtained in the MD simulations. It has been argued that the NMR chemical shift of alkali species can be related to a chemical shift parameter A, where A is defined as the summation …
Date:
May 1, 2000
Creator:
ALAM,TODD M.
Object Type:
Article
System:
The UNT Digital Library
THERMAL CONDUCTIVITY AND OTHER PROPERTIES OF CEMENTITIOUS GROUTS
The thermal conductivity and other properties cementitious grouts have been investigated in order to determine suitability of these materials for grouting vertical boreholes used with geothermal heat pumps. The roles of mix variables such as water/cement ratio, sand/cement ratio and superplasticizer dosage were measured. In addition to thermal conductivity, the cementitious grouts were also tested for bleeding, permeability, bond to HDPE pipe, shrinkage, coefficient of thermal expansion, exotherm, durability and environmental impact. This paper summarizes the results for selected grout mixes. Relatively high thermal conductivities were obtained and this leads to reduction in predicted bore length and installation costs. Improvements in shrinkage resistance and bonding were achieved.
Date:
May 1, 1998
Creator:
ALLAN,M.
Object Type:
Article
System:
The UNT Digital Library
[Project Summary: EcoSpatial Information Database (ESID)]
Summary describing the work completed at AMEC Environment & Infrastructure, Inc. for the EcoSpatial Information Database (ESID). It includes background information on the project funding and sponsorship, goals, methodology, and findings.
Date:
May 2014
Creator:
AMEC Environment & Infrastructure, Inc.
Object Type:
Text
System:
The UNT Digital Library
Cloud to CAD
This paper documents work performed to convert scanned range data to CAD solid model representation. The work successfully developed surface fitting algorithms for quadric surfaces (e.g. plane, cone, cylinder, and sphere), and a segmentation algorithm based entirely on surface type, rather than on a differential metric like Gaussian curvature. Extraction of all CAD-required parameters for quadric surface representation was completed. Approximate face boundaries derived from the original point cloud were constructed. Work to extrapolate surfaces, compute exact edges and solid connectivity was begun, but left incomplete due to funding reductions. The surface fitting algorithms are robust in the face of noise and degenerate surface forms.
Date:
May 1, 2001
Creator:
AMES,ARLO L.
Object Type:
Report
System:
The UNT Digital Library
Use of inelastic analysis in cask design
In this paper, the advantages and disadvantages of inelastic analysis are discussed. Example calculations and designs showing the implications and significance of factors affecting inelastic analysis are given. From the results described in this paper it can be seen that inelastic analysis provides an improved method for the design of casks. It can also be seen that additional code and standards work is needed to give designers guidance in the use of inelastic analysis. Development of these codes and standards is an area where there is a definite need for additional work. The authors hope that this paper will help to define the areas where that need is most acute.
Date:
May 15, 2000
Creator:
AMMERMAN,DOUGLAS J. & BREIVIK,NICOLE L.
Object Type:
Article
System:
The UNT Digital Library