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Investigation of Sodium Distribution in Phosphate Glasses Using Spin-Echo {sup 23}Na NMR
The spatial arrangement of sodium cations for a series of sodium phosphate glasses, xNa{sub 2}O(100-x)P{sub 2}O{sub 5} (x<55), were investigated using {sup 23}Na spin-echo NMR spectroscopy. The spin-echo decay rate is a function of the Na-Na homonuclear dipolar coupling and is related to the spatial proximity of neighboring Na nuclei. The spin-echo decay rate in these sodium phosphate glasses increases non-linearly with higher sodium number density, and thus provides a measure of the Na-Na extended range order. The results of these {sup 23}Na NMR experiments are discussed within the context of several structural models, including a decimated crystal lattice model, cubic dilation lattice model, a hard sphere (HS) random distribution model and a pair-wise cluster hard sphere model. While the experimental {sup 23}Na spin-echo M{sub 2} are described adequately by both the decimated lattice and the random HS model, it is demonstrated that the slight non-linear behavior of M{sub 2} as a function of sodium number density is more correctly described by the random distribution in the HS model. At low sodium number densities the experimental M{sub 2} is inconsistent with models incorporating Na-Na clustering. The ability to distinguish between Na-Na clusters and non-clustered distributions becomes more difficult at higher …
Date:
September 16, 1999
Creator:
ALAM, TODD M.; BOYLE, TIMOTHY J.; BROW, RICHARD K.; CLICK, CAROL C.; CONZONE, SAM; McLAUGHLIN, JAY et al.
Object Type:
Article
System:
The UNT Digital Library
HIGH-INTENSITY, HIGH CHARGE-STATE HEAVY ION SOURCES
There are many accelerator applications for high intensity heavy ion sources, with recent needs including dc beams for RIA, and pulsed beams for injection into synchrotrons such as RHIC and LHC. The present status of sources producing high currents of high charge state heavy ions is reviewed. These sources include ECR, EBIS, and Laser ion sources. Benefits and limitations for these type sources are described. Possible future improvements in these sources are also mentioned.
Date:
August 16, 2004
Creator:
ALESSI,J. G.
Object Type:
Article
System:
The UNT Digital Library
FUTURE PLANS AT BNL: RHIC-II AND eRHIC.
The development of future facilities relevant to the study of deep inelastic scattering at BNL is described.
Date:
April 16, 2007
Creator:
ARONSON,S.
Object Type:
Article
System:
The UNT Digital Library
Thomson scattering diagnostic analyses to determine the energetic particle distributions in TFTR. Final report
Lodestar has been an active participant in the low power Collective Thomson Scattering (CTS) diagnostic at TFTR in collaboration with MIT. Extensive studies were conducted regarding the use of gyrotron scattering as a low cost diagnostic for both energetic ions and alpha particles on TFTR. The numerical scattering code has been improved and compared with similar code developed at JET. The authors have participated and assisted in the CTS experiments through onsite visits and have successfully performed most of the data analysis tasks remotely. Through their analysis on the initial data base accumulated, they are able to understand qualitatively the general features of the anomalous large scattered signal, have proposed an explanation for its generation mechanism, and have suggested a potential new use of CTS as an edge diagnostic.
Date:
February 16, 1995
Creator:
Aamodt, R. E.; Cheung, P. Y. & Russell, D. A.
Object Type:
Report
System:
The UNT Digital Library
Data Torturing and the Misuse of Statistical Tools
Statistical concepts, methods, and tools are often used in the implementation of statistical thinking. Unfortunately, statistical tools are all too often misused by not applying them in the context of statistical thinking that focuses on processes, variation, and data. The consequences of this misuse may be ''data torturing'' or going beyond reasonable interpretation of the facts due to a misunderstanding of the processes creating the data or the misinterpretation of variability in the data. In the hope of averting future misuse and data torturing, examples are provided where the application of common statistical tools, in the absence of statistical thinking, provides deceptive results by not adequately representing the underlying process and variability. For each of the examples, a discussion is provided on how applying the concepts of statistical thinking may have prevented the data torturing. The lessons learned from these examples will provide an increased awareness of the potential for many statistical methods to mislead and a better understanding of how statistical thinking broadens and increases the effectiveness of statistical tools.
Date:
August 16, 1999
Creator:
Abate, Marcey L.
Object Type:
Article
System:
The UNT Digital Library
Electricity: The Road Toward Restructuring
The Public Utility Holding Company Act of 1935 (PUHCA) and the Federal Power Act (FPA) were enacted to eliminate unfair practices and other abuses by electricity and gas holding companies by requiring federal control and regulation of interstate public utility holding companies. Comprehensive energy legislation has passed the House and Senate. The House passed H.R. 6 on April 11, 2003. On July 31, 2003, the Senate suspended debate on S. 14, inserted the text of H.R. 4 (107th Congress) as a substitute, and passed H.R. 6. A conference agreement was reached November 17, 2003, and passed by the House the next day. H.R. 6 includes an electricity title that would, in part, repeal PUHCA, would prospectively repeal the mandatory purchase requirement under PURPA, and would create an electric reliability organization. On June 15, 2004, H.R. 4503, a comprehensive energy policy bill, passed the House.
Date:
October 16, 2002
Creator:
Abel, Amy & Parker, Larry
Object Type:
Report
System:
The UNT Digital Library
Electricity: The Road Toward Restructuring
The Public Utility Holding Company Act of 1935 (PUHCA) and the Federal Power Act (FPA) were enacted to eliminate unfair practices and other abuses by electricity and gas holding companies by requiring federal control and regulation of interstate public utility holding companies. Comprehensive energy legislation has passed the House and Senate. The House passed H.R. 6 on April 11, 2003. On July 31, 2003, the Senate suspended debate on S. 14, inserted the text of H.R. 4 (107th Congress) as a substitute, and passed H.R. 6. A conference agreement was reached November 17, 2003, and passed by the House the next day. H.R. 6 includes an electricity title that would, in part, repeal PUHCA, would prospectively repeal the mandatory purchase requirement under PURPA, and would create an electric reliability organization. On June 15, 2004, H.R. 4503, a comprehensive energy policy bill, passed the House.
Date:
December 16, 2002
Creator:
Abel, Amy & Parker, Larry
Object Type:
Report
System:
The UNT Digital Library
Development of a Real-Time Beryllium Air Monitor Utilizing Microwave Induced Plasma Spectroscopy (MIPAES)
This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) Program Development project at the Los Alamos National laboratory (LANL). The focus of this development has been an innovative beryllium air monitor for on-site' real-time continuous monitoring which overcomes limitations of the previous techniques for beryllium monitoring. A bench-top instrument has been set up and the performance of the instrument has been tested based on a solution aerosol. The sensitivity obtained with the instrument is sufficient to ensure workers can respond at airborne levels well below current exposure regulations. With this versatile, real-time monitor, worker exposure can be greatly reduced.
Date:
July 16, 1999
Creator:
Abeln, S.; Duan, Y.-A.; Olivares, J. A.; Koby, M. & Scopsick, R. C.
Object Type:
Report
System:
The UNT Digital Library
Engineering evaluation of the proposed boiler addition for Minnegasco Energy Center, Minneapolis, Minnesota. Final draft report
The results are reported of a technical evaluation of alternate fuels for the proposed oil and natural gas fired No. 3 boiler at the Minnegasco Energy Center (MEC) located in Minneapolis, Minnesota. This report has been prepared for the Department of Energy, Office of Fuels Conversion for their use in considering an alternate fuel exemption petition submitted by MEC. The fuels considered for the proposed boiler include oil, natural gas, bituminous coal, petroleum coke/coal mixture, refuse-derived fuel (RDF), coal-oil mixtures, and coal/oil dual fuel fired. The purchase of steam from the Northern States Power Company (NSPCo) was also considered as an alternative to construction of another boiler at MEC. Evaluation of each fuel included review of the overall plant design, estimates of capital and O and M costs, salvage value, useful life, and quantities of solid waste produced. The MEC supplies steam and chilled water to the downtown Minneapolis area for building heating and cooling using two presently owned and operated 200,000 lb/h oil/natural gas fired boilers. If the proposed boiler is permitted to burn oil and natural gas, it will be identical in design to the existing boilers. The evaluation showed that the use of oil, natural gas, coal, …
Date:
March 16, 1981
Creator:
Abendroth, H.R. & Poon, A.
Object Type:
Report
System:
The UNT Digital Library
Determination of Heavy Water Purity by Infrared Absorption
The practical application of heavy water purity determination by infrared absorption spectroscopy using standard laboratory equipment was demonstrated in connection with the operation of heavy water-moderated Special Power Excursion Reactor Test (SPERT II) Facillty at the NRTS. (auth)
Date:
January 16, 1962
Creator:
Abernathey, R. M. & Morgan, T. D.
Object Type:
Report
System:
The UNT Digital Library
Growth and Fabrication of GaN/AlGaN Heterojunction Bipolar Transistor
A GaN/AlGaN heterojunction bipolar transistor structure with Mg doping in the base and Si Doping in the emitter and collector regions was grown by Metal Organic Chemical Vapor Deposition in c-axis Al(2)O(3). Secondary Ion Mass Spectrometry measurements showed no increase in the O concentration (2-3x10(18) cm(-3)) in the AlGaN emitter and fairly low levels of C (~4-5x10(17) cm (-3)) throughout the structure. Due to the non-ohmic behavior of the base contact at room temperature, the current gain of large area (~90 um diameter) devices was <3. Increasing the device operating temperature led to higher ionization fractions of the mg acceptors in the base, and current gains of ~10 were obtained at 300 degree C.
Date:
March 16, 1999
Creator:
Abernathy, C. R.; Baca, A. G.; Cao, X. A.; Cho, H.; Dang, G. T.; Donovan, S. M. et al.
Object Type:
Article
System:
The UNT Digital Library
Corrosion of structural materials by lead-based reactor coolants.
Advanced nuclear reactor design has, in recent years, focused increasingly on the use of heavy-liquid-metal coolants, such as lead and lead-bismuth eutectic. Similarly, programs on accelerator-based transmutation systems have also considered the use of such coolants. Russian experience with heavy-metal coolants for nuclear reactors has lent credence to the validity of this approach. Of significant concern is the compatibility of structural materials with these coolants. We have used a thermal convection-based test method to allow exposure of candidate materials to molten lead and lead-bismuth flowing under a temperature gradient. The gradient was deemed essential in evaluating the behavior of the test materials in that should preferential dissolution of components of the test material occur we would expect dissolution in the hotter regions and deposition in the colder regions, thus promoting material transport. Results from the interactions of a Si-rich mild steel alloy, AISI S5, and a ferritic-martensitic stainless steel, HT-9, with the molten lead-bismuth are presented.
Date:
November 16, 2000
Creator:
Abraham, D. P.; Leibowitz, L.; Maroni, V. A.; McDeavitt, S. M. & Raraz, A. G.
Object Type:
Article
System:
The UNT Digital Library
ADVANCED COMPOSITE WIND TURBINE BLADE DESIGN BASED ON DURABILITY AND DAMAGE TOLERANCE
The objective of the program was to demonstrate and verify Certification-by-Analysis (CBA) capability for wind turbine blades made from advanced lightweight composite materials. The approach integrated durability and damage tolerance analysis with robust design and virtual testing capabilities to deliver superior, durable, low weight, low cost, long life, and reliable wind blade design. The GENOA durability and life prediction software suite was be used as the primary simulation tool. First, a micromechanics-based computational approach was used to assess the durability of composite laminates with ply drop features commonly used in wind turbine applications. Ply drops occur in composite joints and closures of wind turbine blades to reduce skin thicknesses along the blade span. They increase localized stress concentration, which may cause premature delamination failure in composite and reduced fatigue service life. Durability and damage tolerance (D&DT) were evaluated utilizing a multi-scale micro-macro progressive failure analysis (PFA) technique. PFA is finite element based and is capable of detecting all stages of material damage including initiation and propagation of delamination. It assesses multiple failure criteria and includes the effects of manufacturing anomalies (i.e., void, fiber waviness). Two different approaches have been used within PFA. The first approach is Virtual Crack Closure Technique …
Date:
February 16, 2012
Creator:
Abumeri, Galib & Abdi, Frank
Object Type:
Report
System:
The UNT Digital Library
Multidimensional solitons in fiber arrays
We demonstrate that nonlinear optical fiber arrays can support stable soliton-like pulses with finite energy. The bound state that we have found is localized both in time and in a spatial domain in the direction perpendicular to the pulse propagation. We have proved the boundedness of the Hamiltonian function for the array. Finally, numerical studies support our analytical conclusions.
Date:
August 16, 1993
Creator:
Aceves, A. B.; De Angelis, C.; Rubenchik, A. M. & Turitsyn, S. K.
Object Type:
Article
System:
The UNT Digital Library
Computer modeling in the design and evaluation of electric and hybrid vehicles
This demonstration project uses modern simulation techniques to illustrate the important technologies and design variables that an auto-designer would consider in production a high efficiency, low emissions vehicle. Simulation and modeling techniques use the idea of capturing the relationships between real components of the systems with mathematical equations. These equations are then solved on a computer to simulate the behavior or performance of the system under various conditions. In the current demonstration project, we focus on many variations of a hydrogen-powered vehicle.
Date:
August 16, 1996
Creator:
Aceves, S. M.; Smith, J. R. & Johnson, N. L.
Object Type:
Article
System:
The UNT Digital Library
High Precision Droplet Based New Form Manufacturing
In collaboration with the University of California at Irvine (UCI), we are working on a new technology that relies on the precise deposition of nanoliter molten-metal droplets that are targeted onto a substrate by electrostatic charging and deflection. By this way, three-dimensional (3D) structural materials can be manufactured microlayer by microlayer. Because the volume of the droplets are small, they rapidly solidify on impact, bringing forth a material component with fine grain structures which lead to enhanced material properties (e.g., strength). UCI is responsible for an experimental investigation of the manufacturing feasibility of this process. LLNL has unique expertise in the computational modeling of 3D heat transfer and solid mechanics and has the large-scale computer resources necessary to model this large system. Process modeling will help move this technology from the bench-top to an industrial process. Applications at LLNL include rapid prototyping of metal parts and manufacturing new alloys by co-jetting different metals.
Date:
September 16, 1999
Creator:
Aceves, S.; Hadjiconstantinou, N.; Miller, W. O.; Orme, M.; Sahai, V. & Shapiro, A. B.
Object Type:
Report
System:
The UNT Digital Library
Education Vouchers: Constitutional Issues and Cases
This report details the constitutional standards that currently apply to indirect aid programs and summarizes all of the pertinent state and federal court decisions, including the Ohio case that will be heard by the Supreme Court. On September 25, 2001, the Supreme Court agreed to review a case raising the controversial issue of the constitutionality of education vouchers. In Zelman v. Simmons-Harris the Sixth Circuit held Ohio’s Pilot Scholarship Program, which provided up to $2500 to help low-income students in Cleveland’s public schools attend private schools in the city, to violate the establishment of religion clause of the First Amendment.
Date:
July 16, 2002
Creator:
Ackerman, David M.
Object Type:
Report
System:
The UNT Digital Library
Waste form development and characterization in pyrometallurgical treatment of spent nuclear fuel.
Electrometallurgical treatment is a compact, inexpensive method that is being developed at Argonne National Laboratory to deal with spent nuclear fuel, primarily metallic and oxide fuels. In this method, metallic nuclear fuel constituents are electrorefined in a molten salt to separate uranium from the rest of the spent fuel. Oxide and other fuels are subjected to appropriate head end steps to convert them to metallic form prior to electrorefining. The treatment process generates two kinds of high-level waste--a metallic and a ceramic waste. Isolation of these wastes has been developed as an integral part of the process. The wastes arise directly from the electrorefiner, and waste streams do not contain large quantities of solvent or other process fluids. Consequently, waste volumes are small and waste isolation processes can be compact and rapid. This paper briefly summarizes waste isolation processes then describes development and characterization of the two waste forms in more detail.
Date:
April 16, 1998
Creator:
Ackerman, J.
Object Type:
Article
System:
The UNT Digital Library
Search for Dark Matter Satellites Using the FERMI-LAT
Numerical simulations based on the {Lambda}CDM model of cosmology predict a large number of as yet unobserved Galactic dark matter satellites. We report the results of a Large Area Telescope (LAT) search for these satellites via the {gamma}-ray emission expected from the annihilation of weakly interacting massive particle (WIMP) dark matter. Some dark matter satellites are expected to have hard {gamma}-ray spectra, finite angular extents, and a lack of counterparts at other wavelengths. We sought to identify LAT sources with these characteristics, focusing on {gamma}-ray spectra consistent with WIMP annihilation through the b{bar b} channel. We found no viable dark matter satellite candidates using one year of data, and we present a framework for interpreting this result in the context of numerical simulations to constrain the velocity-averaged annihilation cross section for a conventional 100 GeV WIMP annihilating through the b{bar b} channel.
Date:
August 16, 2012
Creator:
Ackermann, M.; Albert, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D. et al.
Object Type:
Article
System:
The UNT Digital Library
Demonstration of Key Elements of a Dual Phase Argon Detection System Suitable for Measurement of Coherent Neutrino-Nucleus Scattering
This feasibility study sought to demonstrate several necessary steps in a research program whose ultimate goal is to detect coherent scattering of reactor antineutrinos in dual-phase noble liquid detectors. By constructing and operating a Argon gas-phase drift and scintillation test-bed, the study confirmed important expectations about sensitivity of these detectors, and thereby met the goals set forth in our original proposal. This work has resulted in a successful Lab-Wide LDRD for design and deployment of a coherent scatter detector at a nuclear reactor, and strong interest by DOE Office of Science. In recent years, researchers at LLNL and elsewhere have converged on a design approach for a new generation of very low noise, low background particle detectors known as two-phase noble liquid/noble gas ionization detectors. This versatile class of detector can be used to detect coherent neutrino scattering-an as yet unmeasured prediction of the Standard Model of particle physics. Using the dual phase technology, our group would be the first to verify the existence of this process. Its (non)detection would (refute)validate central tenets of the Standard Model. The existence of this process is also important in astrophysics, where coherent neutrino scattering is assumed to play an important role in energy …
Date:
April 16, 2007
Creator:
Adam, B.; Celeste, W.; Christian, H.; Wolfgang, S. & Norman, M.
Object Type:
Report
System:
The UNT Digital Library
Nozzle.
Patent for a hose nozzle with increased capacity and efficiency. Includes instructions and illustrations.
Date:
March 16, 1897
Creator:
Adams, Don B.
Object Type:
Patent
System:
The Portal to Texas History
Electric Signal System
Patent for electric signal system. Illustration included.
Date:
May 16, 1905
Creator:
Adams, Edwin Johnson
Object Type:
Patent
System:
The Portal to Texas History
Pion, kaon, proton and anti-proton transverse momentum distributions from p+p and d+Au collisions at sqrt(sNN) = 200 GeV
Identified mid-rapidity particle spectra of {pi}{sup {+-}}, K{sup {+-}}, and p({bar p}) from 200 GeV p+p and d+Au collisions are reported. A time-of-flight detector based on multi-gap resistive plate chamber technology is used for particle identification. The particle-species dependence of the Cronin effect is observed to be significantly smaller than that at lower energies. The ratio of the nuclear modification factor (R{sub dAu}) between (p+ {bar p}) and charged hadrons (h) in the transverse momentum range 1.2 < p{sub T} < 3.0 GeV/c is measured to be 1.19 {+-} 0.05(stat) {+-} 0.03(syst) in minimum-bias collisions and shows little centrality dependence. The yield ratio of (p + {bar p})/h in minimum-bias d+Au collisions is found to be a factor of 2 lower than that in Au+Au collisions, indicating that the Cronin effect alone is not enough to account for the relative baryon enhancement observed in heavy ion collisions at RHIC.
Date:
September 16, 2003
Creator:
Adams, J.; Adler, C.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D. et al.
Object Type:
Article
System:
The UNT Digital Library
Tank waste information network system II (TWINS2) year 2000 compliance assurance plan
The scope of this plan includes the Tank Waste Information Network System II (TWINS2) that contains the following major components: Tank Characterization Database (TCD), Tank Vapor Database (TVD), Data Source Access (DSA), automated Tank Characterization Report, Best-Basis Inventory Model (BBIM), and Tracker (corrective action tracking) function. The automated Tank Characterization Report application currently in development also will reside on-the TWINS system as will the BBIM. Critical inputs to TWINS occur from the following databases: Labcore and SACS. Output does not occur from TWINS to these two databases.
Date:
April 16, 1998
Creator:
Adams, M.R.
Object Type:
Report
System:
The UNT Digital Library