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Comments Regarding "Study of Molecular Interactions in Binary Mixtures of Formamide with 2-Methoxyethanol and 2-Ethoxyethanol at Varying Temperatures" (open access)

Comments Regarding "Study of Molecular Interactions in Binary Mixtures of Formamide with 2-Methoxyethanol and 2-Ethoxyethanol at Varying Temperatures"

This article provides comments on "Study of Molecular Interactions in Binary Mixtures of Formamide with 2-Methoxyethanol and 2-Ethoxyethanol at Varying Temperatures," published in 'Physics and Chemistry of Liquids,' 2013.
Date: June 3, 2013
Creator: Acree, William E. (William Eugene)
System: The UNT Digital Library
Equivalence of dipole correction and Coulomb cutoff techniques in supercell calculations (open access)

Equivalence of dipole correction and Coulomb cutoff techniques in supercell calculations

Article on the equivalence of dipole correction and Coulomb cutoff techniques in supercell calculations. In this work, the authors compare the dipole correction and Coulomb cutoff methods under the same conditions in the framework of plane-wave based density-functional theory.
Date: June 3, 2008
Creator: Yu, Liping; Ranjan, Vivek; Lu, W.; Bernholc, Jerry & Buongiorno Nardelli, Marco
System: The UNT Digital Library
Librarians and Technology: Things to Consider (open access)

Librarians and Technology: Things to Consider

Article on librarians and technology and things to consider.
Date: June 3, 2014
Creator: Monahan, Jo
System: The UNT Digital Library
Novel structural phenomena at the maximum T{sub c} in 123 and HgBa{sub 2}CuO{sub 4+{delta}} superconductors : evidence for a structural response that competes with superconductivity. (open access)

Novel structural phenomena at the maximum T{sub c} in 123 and HgBa{sub 2}CuO{sub 4+{delta}} superconductors : evidence for a structural response that competes with superconductivity.

Structural distortions that compete with superconductivity have been investigated in two systems where oxygen content can be used to vary the doping continuously from the under doped state, through the maximum T{sub c} into the over doped state. In the 123 system, (La{sub 1{minus}x}Ca{sub x})(Ba{sub 1.75{minus}x}La{sub 0.25+x})Cu{sub 3}O{sub 7+{delta}}, the buckling of the CuO{sub 2} planes goes through a maximum at the maximum T{sub c}. In HgBa{sub 2}CuO{sub 4+{delta}}, where buckling of the CuO{sub 2} planes is not available as a structural degree of freedom, there is a plateau at the maximum T{sub c} where the unit cell volume expands as oxygen is added while the charge transfer and T{sub c} remain constant. These unusual structural phenomena upon crossing through the maximum T{sub c} are hypothesized to be a response of the crystal structure to the electronic structure, with the structural distortions competing with superconductivity, or lowering the T{sub c} from what it would otherwise be.
Date: June 3, 1998
Creator: Jorgensen, J. D.
System: The UNT Digital Library
Faulty assumptions for repository requirements (open access)

Faulty assumptions for repository requirements

Long term performance requirements for a geologic repository for spent nuclear fuel and high-level waste are based on assumptions concerning water use and subsequent deaths from cancer due to ingesting water contaminated with radio isotopes ten thousand years in the future. This paper argues that the assumptions underlying these requirements are faulty for a number of reasons. First, in light of the inevitable technological progress, including efficient desalination of water, over the next ten thousand years, it is inconceivable that a future society would drill for water near a repository. Second, even today we would not use water without testing its purity. Third, today many types of cancer are curable, and with the rapid progress in medical technology in general, and the prevention and treatment of cancer in particular, it is improbable that cancer caused by ingesting contaminated water will be a sign&ant killer in the far future. This paper reviews the performance requirements for geological repositories and comments on the difficulties in proving compliance in the face of inherent uncertainties. The already tiny long-term risk posed by a geologic repository is presented and contrasted with contemporary every day risks. A number of examples of technological progress, including cancer treatments, …
Date: June 3, 1999
Creator: Sutcliffe, W G
System: The UNT Digital Library
Transient oxide phases and scale strain in MCrAlY : a light scattering study. (open access)

Transient oxide phases and scale strain in MCrAlY : a light scattering study.

We have used Raman ''fingerprinting'' to investigate the temperature dependence of the transient oxide phases in the scale formed on MCrAl and MCrAlY (M=Ni,Co) in the temperature range 300 to 1200 C. In particular, by extending our Raman spectra to include second order scattering, we are able to track the evolution of NiO in the scales. We find that the inclusion of Y, while improving scale adhesion, inhibits the formation of Co oxide. We have also exploited the strain dependence of ruby fluorescence to extract the residual strain in the oxide scale.
Date: June 3, 1998
Creator: Renusch, D.
System: The UNT Digital Library
Critical comparison of 3D imaging approaches (open access)

Critical comparison of 3D imaging approaches

Currently three imaging spectrometer architectures, tunable filter, dispersive, and Fourier transform, are viable for imaging the universe in three dimensions. There are domains of greatest utility for each of these architectures. The optimum choice among the various alternative architectures is dependent on the nature of the desired observations, the maturity of the relevant technology, and the character of the backgrounds. The domain appropriate for each of the alternatives is delineated; both for instruments having ideal performance as well as for instrumentation based on currently available technology. The environment and science objectives for the Next Generation Space Telescope will be used as a specific representative case to provide a basis for comparison of the various alternatives.
Date: June 3, 1999
Creator: Bennett, C L
System: The UNT Digital Library
Refracted x-ray fluorescence (RXF) applied to the study of thermally grown oxide scales on Fe-Cr-Ni-(RE) alloys. (open access)

Refracted x-ray fluorescence (RXF) applied to the study of thermally grown oxide scales on Fe-Cr-Ni-(RE) alloys.

Refracted X-Ray Fluorescence (RXF) is applied to the study of the thermally grown scales on Fe25Cr20Ni(RE) alloys. The evolution of chromia scales is investigated for alloys containing reactive elements (RE) Y and Zr as well as the corresponding RE-free alloy. For these alloys, scale compositions, scale thicknesses and growth rates are measured and information about concentration depth profiles is obtained.
Date: June 3, 1998
Creator: Koshelev, I.
System: The UNT Digital Library
Growth of alumina scale on Fe-Cr-Al : a multiprobe study. (open access)

Growth of alumina scale on Fe-Cr-Al : a multiprobe study.

The use of local probes at specific spatial locations provides a clear picture of the scale growth. The thermal evolution of the oxide scale on 72Fe-18Cr-10Al-0.15Hf (at.%) has been investigated using a number of spectroscopic techniques. Well defined regions ({approx}70 mm in diameter) were probed by a battery of techniques as a function of oxidation at different temperatures (Between 800 C--1100 C). This study provides information about the dependence of scale evolution on fluctuations in the local composition and/or grain structure of the starting material. Results suggest that properties of the starting material, which were not investigated in this study, strongly influence the scale evolution, even to the stage of mature scales.
Date: June 3, 1998
Creator: Veal, B. W.
System: The UNT Digital Library
Systems modeling and analysis of heavy ion drivers for inertial fusion energy (open access)

Systems modeling and analysis of heavy ion drivers for inertial fusion energy

A computer model for systems analysis of heavy ion drivers based on induction linac technology has been used to evaluate driver designs for inertial fusion energy (IFE). Design parameters and estimated costs have been determined for drivers with various ions, different charge states, different front-end designs, with and without beam merging, and various pulse compression and acceleration schedules. We have examined the sensitivity of the results to variations in component cost assumptions, design constraints, and selected design parameters
Date: June 3, 1998
Creator: Meier, W. R.
System: The UNT Digital Library
Stresses in thermally grown alumina scales near edges and corners. (open access)

Stresses in thermally grown alumina scales near edges and corners.

We have investigated the residual stress near edges and corners of thermally grown alumina scales. Micro-fluorescence measurements, performed on alloys with composition Fe-5Cr-28Al (at.%, bal. Fe) oxidized at 900 C, showed a large (>50%) reduction in hydrostatic stress in the vicinity of edges and corners. Surprisingly, stress relaxation persists out to distances ten times the scale thickness from the edge. Finite element analysis calculations confirm the experimental results and provide a considerably more detailed picture of the stress distribution and its components.
Date: June 3, 1998
Creator: Grimsditch, M.
System: The UNT Digital Library
Improved assessment of aviation hazards to ground facilities using a geographical information system (open access)

Improved assessment of aviation hazards to ground facilities using a geographical information system

A computer based system for performing probabilistic safety assessments (PSAs) of aircraft crashes to ground structures is under development. The system called ACRA (aircraft crash risk assessment) employs a GIS (geographical information system) for locating, mapping, and characterizing ground structures; and a multiparameter data base system that supports the analytical PRA (probabilistic risk assessment) model for determining PSAs for aircraft crashes. The Salt Lake City International Airport (SLC) is being employed as the base case for study and application of ACRA and evaluation of the projected safety assessment.
Date: June 3, 1996
Creator: Sandquist, G. M.; Slaughter, D. M. & Kimura, C. Y.
System: The UNT Digital Library
Emittance growth in heavy ion rings due to effects of space charge and dispersion (open access)

Emittance growth in heavy ion rings due to effects of space charge and dispersion

We review the derivation of moment equations which include the effects of space charge and dispersion in bends first presented in ref [1]. These equations generalize the familiar envelope equations to include the dispersive effects of bends. We review the application of these equations to the calculation of the change in emittance resulting from a sharp transition from a straight section to a bend section, using an energy conservation constraint. Comparisons of detailed 2D and 3D simulations of intense beams in rings using the WARP code (refs [2,3]) are made with results obtained from the moment equations. We also compare the analysis carried out in ref [1], to more recent analyses, refs [4,5]. We further examine self-consistent distributions of beams in bends and discuss the relevance of these distributions to the moment equation formulation.
Date: June 3, 1998
Creator: Barnard, J.J., LLNL
System: The UNT Digital Library
Hard x-ray production from high intensity laser solid interactions (open access)

Hard x-ray production from high intensity laser solid interactions

Intense laser (> 10{sup 21} W/cm{sup 2}) driven hard x-ray sources offer a new alternative to conventional electron accelerator bremsstrahlung sources. These laser driven sources offer considerable simplicity in design and cost advantage for multiple axis views and have the potential for much higher spatial and temporal resolution than is achievable with accelerator sources We have begun a series of experiments using the Petawatt Laser system at LLNL to determine the potential of these sources for radiography applications Absolutely calibrated spectra extending to 20 MeV and high resolution radiographs through a {rho}r{>=}150 gm/cm{sup 2} have been obtained The physics of these sources and the scaling relationships and laser technology required to provide the dose levels necessary for radiography applications will be discussed Diagnostics of the laser produced electrons and photons will be addressed
Date: June 3, 1998
Creator: Sefcik, J. A.
System: The UNT Digital Library
Estimate of air carrier and air taxi crash frequencies from high altitude en route flight operations (open access)

Estimate of air carrier and air taxi crash frequencies from high altitude en route flight operations

In estimating the frequency of an aircraft crashing into a facility, it has been found convenient to break the problem down into two broad categories. One category estimates the aircraft crash frequency due to air traffic from nearby airports, the so-called near-airport environment. The other category estimates the aircraft crash frequency onto facilities due to air traffic from airways, jet routes, and other traffic flying outside the near-airport environment The total aircraft crash frequency is the summation of the crash frequencies from each airport near the facility under evaluation and from all airways, jet routes, and other traffic near the facility of interest. This paper will examine the problems associated with the determining the aircraft crash frequencies onto facilities outside the near-airport environment. This paper will further concentrate on the estimating the risk of aircraft crashes to ground facilities due to high altitude air carrier and air taxi traffic. High altitude air carrier and air taxi traffic will be defined as all air carrier and air taxi flights above 18,000 feet Mean Sea Level (MSL).
Date: June 3, 1996
Creator: Sanzo, D.; Kimura, C.Y. & Prassinos, P.G.
System: The UNT Digital Library
Blast wave diagnostic for the petawatt laser system (open access)

Blast wave diagnostic for the petawatt laser system

We report on a diagnostic to measure the trajectory of a blast wave propagating through a plastic target 400 {micro}m thick. This blast wave is generated by the irradiation of the front surface of the target with {approximately} 400 J of 1 {micro}m laser radiation in a 20 ps pulse focused to a {approximately} 50 {micro}m diameter spot, which produces an intensity in excess of 1O{sup 18} W/cm{sup 2}. These conditions approximate a point explosion and a blast wave is predicted to be generated with an initial pressure nearing 1 Gbar which decays as it travels approximately radially outward from the interaction region We have utilized streaked optical pyrometry of the blast front to determine its time of arrival at the rear surface of the target Applications of a self-similar Taylor-Sedov blast wave solution allows the amount of energy deposited to be estimated The experiment, LASNEX design simulations and initial results are discussed.
Date: June 3, 1998
Creator: Budil, K. S.
System: The UNT Digital Library
Abraham Model Correlations for Describing Solute Transfer into 2-Butoxyethanol from Both Water and the Gas Phase at 298 K (open access)

Abraham Model Correlations for Describing Solute Transfer into 2-Butoxyethanol from Both Water and the Gas Phase at 298 K

Article on Abraham model correlations for describing solute transfer into 2-butoxyethanol from both water and the gas phase at 298 K.
Date: June 3, 2015
Creator: Sedov, Igor A.; Stolov, Mikhail; Hart, Erin; Grover, Damini; Zettl, Heidi; Koshevarova, Victoria et al.
System: The UNT Digital Library
Robust Bearing Estimation for 3-Component Stations (open access)

Robust Bearing Estimation for 3-Component Stations

A robust bearing estimation process for 3-component stations has been developed and explored. The method, called SEEC for Search, Estimate, Evaluate and Correct, intelligently exploits the in- herent information in the arrival at every step of the process to achieve near-optimal results. In particular, the approach uses a consistent framework to define the optimal time-frequency windows on which to make estimates, to make the bearing estimates themselves, to construct metrics helpful in choosing the better estimates or admitting that the bearing is immeasurable, andjinally to apply bias corrections when calibration information is available to yield a single final estimate. The method was applied to a small but challenging set of events in a seismically active region. The method demonstrated remarkable utility by providing better estimates and insights than previously available. Various monitoring implications are noted fiom these findings.
Date: June 3, 1999
Creator: Claassen, John P.
System: The UNT Digital Library
Tevatron performance goals for the coming decade (open access)

Tevatron performance goals for the coming decade

Fermilab is in the midst of a program to raise the luminosity in the Tevatron proton-antiproton collider by at least a factor of five above the currently achieved level of 1 .6x10{sup 31} cm{sup -2}sec{sup -l} Components of this program include the construction of a new synchrotron, the Main Injector, a new antiproton storage ring, the Recycler, and a variety of improvements to the existing Antiproton Source and Tevatron. Commissioning of these components will be underway in early 1999 with the next Tevatron collider run scheduled to start in April 2000. Initial commissioning experience with these systems will be described, along with developments underway to support further Tevatron luminosity enhancements over the coming decade.
Date: June 3, 1999
Creator: Holmes, Stephen D.
System: The UNT Digital Library
PROCESS LINE RESOURCE IMPACTS FROM MASTER SCHEDULE VARIATIONS (open access)

PROCESS LINE RESOURCE IMPACTS FROM MASTER SCHEDULE VARIATIONS

None
Date: June 3, 2002
Creator: BURNSIDE, ROBERT J.; GONZALES-LUJAN, JOHNELL M. & TOMPKINS, GEORGE
System: The UNT Digital Library
Tune Measurement in the SNS Ring (open access)

Tune Measurement in the SNS Ring

None
Date: June 3, 2002
Creator: Cameron, P.; Fedotov, A. & Malitsky, N.
System: The UNT Digital Library
Studies of the Coherent Half Integer Resonance. (open access)

Studies of the Coherent Half Integer Resonance.

We present studies of space-charge-induced beam profile broadening at high intensities in the Proton Storage Ring (PSR) at Los Alamos National Laboratory. Previous work has associated the observed broadening in the vertical direction with the coherent half integer resonance. Here, we study the effect of the space charge environment on this resonance; specifically, we investigate the strength of the resonance versus beam intensity, longitudinal bunching factor, transverse lattice tune, and two different beam injection scenarios. For each case, detailed particle-in-cell simulations are combined with experimental results to elucidate the behavior and sensitivity of the beam resonance response.
Date: June 3, 2002
Creator: Cousineau, S.; Holmes, J.; Galambos, J.; Macek, R.; Fedotov, A. & Wei, J.
System: The UNT Digital Library
Passive Corrosion Behavior of Alloy 22 in Multi-Ionic Aqueous Environments (open access)

Passive Corrosion Behavior of Alloy 22 in Multi-Ionic Aqueous Environments

In current waste packaging design, Alloy 22 (Ni-22Cr-13Mo-3W-3Fe) has been chosen as the candidate materials to fabricate a 2 cm outer layer of the high-level nuclear waste containers, as part of proposed geological repository at Yucca Mountain, Nevada. During the repository period, the container materials will be subject to the corrosion due to its exposure to the multi-ionic aqueous environments. Although Alloy 22 has demonstrated excellent corrosion resistance, but accumulation of small yearly corrosion rate for 10,000 or more years can be significant enough. The goal of this research is to seek alternative techniques to obtain a reasonably confident corrosion rate determination, since the conventional weight loss technique requires many years to achieve a detectable weight loss in Alloy 22 samples. This paper will discuss the latest experiment results in using potentiostatic technique to determine passive dissolution rates.
Date: June 3, 2002
Creator: Lian, T.; Estill, J. C.; Hust, G. A.; Fix, D. V. & Rebak, R. B.
System: The UNT Digital Library
BEAM DYNAMICS SIMULATIONS IN THE RAPID CYCLING MEDICAL SYNCHROTRON. (open access)

BEAM DYNAMICS SIMULATIONS IN THE RAPID CYCLING MEDICAL SYNCHROTRON.

The Rapid Cycling Medical Synchrotron (RCMS) accelerator is under conceptual design at BNL. We report the results of the beam dynamics studies in the current design RCMS ring lattice with simulation program ORBIT++. In this paper, the designed RCMS ring lattice, the important physical parameters and the simulation program employed in this study are overviewed. The major elements and the numerical parameters included in the simulations are listed and discussed. The evolution of longitudinal beam properties, such as bunch length, bunch height and particle distributions, under RF voltage ramping are studied. The simulation results of the 6D beam dynamics during acceleration including phase space and emittance evolution are presented. Finally, the space charge effects such as tune shift and emittance growth in the RCMS ring are investigated and discussed.
Date: June 3, 2002
Creator: Beebe-Wang, J.; D Imperio, N.; Luccio, A. U. & Zhang, S. Y.
System: The UNT Digital Library