States

Production of slow-positron beams with an electron linac (open access)

Production of slow-positron beams with an electron linac

Intense, pulsed beams of low-energy positrons have been produced by a high-energy beam from an electron linac. The production efficiency for low-energy positrons has been determined for electrons with 60 to 120 MeV energy, low-energy positron beams from a linac can be of much higher intensity than those beams currently derived from radioactive sources.
Date: March 26, 1982
Creator: Howell, R. H.; Alvarez, R. A. & Stanek, M.
Object Type: Article
System: The UNT Digital Library
Structural Changes Observed in (Mo /sub 6/Ru /sub 4/)/sub x/B/sub 1-x/ Amorphous Alloys Observed with Positron Annihilation (open access)

Structural Changes Observed in (Mo /sub 6/Ru /sub 4/)/sub x/B/sub 1-x/ Amorphous Alloys Observed with Positron Annihilation

Changes in the structure of (Mo /sub 6/Ru /sub 4/)/sub x/B/sub 1-x/ amorphous alloys were observed in positron annihilation analysis using both positron lifetime and Doppler broadening techniques. The changes were introduced into the alloy either by varying the boron fraction or by neutron irradiation. Similar results were observed both in the irradiated alloys and those with vacant boron sites. The positron annihilation data suggest that the modified structure contains regions of open volume and that the positrons interact with those regions.
Date: March 26, 1982
Creator: Howell, R. H. & Johnson, W. L.
Object Type: Article
System: The UNT Digital Library
Studies in Development Immunogenetics. Annual Progress Report (open access)

Studies in Development Immunogenetics. Annual Progress Report

This contract provides the research support for a group concerned with a relatively large range of problems. The integrating thread that runs through it is that of an interest in development and its genetic regulation, mainly in complex organisms and with an emphasis on the immune system as a model for developmental analysis and as a tool for following the development of other systems, especially the brain. It includes studies of biochemical genetics, primarily from a developmental viewpoint and with particular regard to defense mechanisms, and cellular aspects of the immune system. It extends into the area of cancer immunology and cell specificities as related to tumor systems, primarily from an immunogenetic viewpoint and with particular reference to leukemias in the mouse, and to disruptions of genetic control mechanisms in tumor development, especially as approached through the reappearance of fetal antigens associated with tumor development.
Date: March 26, 1975
Creator: Owen, R. D.
Object Type: Report
System: The UNT Digital Library
Hydrodesulfurization and hydrodenitrogenation catalysts obtained from coal mineral matter. [Patent application] (open access)

Hydrodesulfurization and hydrodenitrogenation catalysts obtained from coal mineral matter. [Patent application]

A hydrotreating catalyst is prepared from coal mineral matter obtained by low temperature ashing coals of relatively low bassanite content by the steps of: (a) depositing on the low temperature ash 0.25 to 3 grams of an iron or nickel salt in water per gram of ash and drying a resulting slurry; (b) crushing and sizing a resulting solid; and (c) heating the thus-sized solid powder in hydrogen.
Date: March 26, 1981
Creator: Hwai-der Liu, K. & Hamrin, C.E. Jr.
Object Type: Patent
System: The UNT Digital Library
Mathematical definition of protocol translation (open access)

Mathematical definition of protocol translation

This paper mathematically defines protocol translation which is a function employed to interconnect different computer networks. An example of an application is a gateway.
Date: March 26, 1982
Creator: Ong, M. M.
Object Type: Article
System: The UNT Digital Library
Minimally refined biomass fuel. [carbohydrate-water-alcohol mixture] (open access)

Minimally refined biomass fuel. [carbohydrate-water-alcohol mixture]

A minimally refined fluid composition, suitable as a fuel mixture and derived from biomass material, is comprised of one or more water-soluble carbohydrates such as sucrose, one or more alcohols having less than four carbons, and water. The carbohydrate provides the fuel source; water-solubilizes the carbohydrate; and the alcohol aids in the combustion of the carbohydrate and reduces the viscosity of the carbohydrate/water solution. Because less energy is required to obtain the carbohydrate from the raw biomass than alcohol, an overall energy savings is realized compared to fuels employing alcohol as the primary fuel.
Date: March 26, 1981
Creator: Pearson, R. K. & Hirschfeld, T. B.
Object Type: Patent
System: The UNT Digital Library
Positron-annihilation studies of molybdenum irradiated by protons, neutrons, or electrons (open access)

Positron-annihilation studies of molybdenum irradiated by protons, neutrons, or electrons

Annealed molybdenum was irradiated at room temperature by energetic protons or neutrons and the fluence and recoil energy dependence of two traps was measured. Comparison of trapping rates with calculations of damage energy correlates high energy recoils with the short lifetime trap and low energy recoils with the longer lifetime.
Date: March 26, 1982
Creator: Howell, R.H.
Object Type: Article
System: The UNT Digital Library
Radioactive liquid wastes discharged to ground in the 200 Areas during 1978 (open access)

Radioactive liquid wastes discharged to ground in the 200 Areas during 1978

This document is issued quarterly for the purpose of summarizing the radioactive liquid wastes that have been discharged to the ground in the 200 Areas. In addition to data for 1978, cumulative data since plant startup are presented. Also, in this document is a listing of decayed activity to the various plant sites.
Date: March 26, 1979
Creator: Anderson, J. D. & Poremba, B. E.
Object Type: Report
System: The UNT Digital Library
Problems associated with the extension of the stratigraphic units of south-central Washington. Part II. The post basalt sediments (open access)

Problems associated with the extension of the stratigraphic units of south-central Washington. Part II. The post basalt sediments

There are four district stratigraphic units within the Pasco Basin which if interpreted on the basis of recent field evidence and described properly could be traced over most of southeastern Washington. At the present time these post-basalt sediments are described in the literature in such a way as to make extensive correlations impossible. Some descriptions overlap more than one unit whereas others describe only a part of the unit. It is proposed that all interested geologists in the Pacific Northwest now consider reconciling the differences which exist in the names and descriptions of those sedimentary deposits in light of this new evidence.
Date: March 26, 1965
Creator: Brown, D.J. & Brown, R.E.
Object Type: Report
System: The UNT Digital Library
LOFT 3C cable tray and ladder seismic analysis (open access)

LOFT 3C cable tray and ladder seismic analysis

The LOFT 3C cable tray and ladder were analyzed for LOCE and Safe Shutdown Earthquake (SSE) seismic loads by using equivalent static loads. Design changes were recommended to alleviate overstress conditions.
Date: March 26, 1979
Creator: Mosby, W.R.
Object Type: Report
System: The UNT Digital Library
Book Review Geostatistical Analysis of Compositional Data (open access)

Book Review Geostatistical Analysis of Compositional Data

Compositional data are represented as vector variables with individual vector components ranging between zero and a positive maximum value representing a constant sum constraint, usually unity (or 100 percent). The earth sciences are flooded with spatial distributions of compositional data, such as concentrations of major ion constituents in natural waters (e.g. mole, mass, or volume fractions), mineral percentages, ore grades, or proportions of mutually exclusive categories (e.g. a water-oil-rock system). While geostatistical techniques have become popular in earth science applications since the 1970s, very little attention has been paid to the unique mathematical properties of geostatistical formulations involving compositional variables. The book 'Geostatistical Analysis of Compositional Data' by Vera Pawlowsky-Glahn and Ricardo Olea (Oxford University Press, 2004), unlike any previous book on geostatistics, directly confronts the mathematical difficulties inherent to applying geostatistics to compositional variables. The book righteously justifies itself with prodigious referencing to previous work addressing nonsensical ranges of estimated values and error, spurious correlation, and singular cross-covariance matrices.
Date: March 26, 2007
Creator: Carle, S F
Object Type: Article
System: The UNT Digital Library
Colliding with a crunching bubble (open access)

Colliding with a crunching bubble

In the context of eternal inflation we discuss the fate of Lambda = 0 bubbles when they collide with Lambda< 0 crunching bubbles. When the Lambda = 0 bubble is supersymmetric, it is not completely destroyed by collisions. If the domain wall separating the bubbles has higher tension than the BPS bound, it is expelled from the Lambda = 0 bubble and does not alter its long time behavior. If the domain wall saturates the BPS bound, then it stays inside the Lambda = 0 bubble and removes a finite fraction of future infinity. In this case, the crunch singularity is hidden behind the horizon of a stable hyperbolic black hole.
Date: March 26, 2007
Creator: Freivogel, Ben; Freivogel, Ben; Horowitz, Gary T. & Shenker, Stephen
Object Type: Article
System: The UNT Digital Library
Poland Becoming a Member of the Global Nuclear Energy Partnership, Vol. 1. (open access)

Poland Becoming a Member of the Global Nuclear Energy Partnership, Vol. 1.

Within a constrained carbon environment, the risks of future natural gas supply, and the need to move to market-based electricity prices, the study team found: (1) the deployment of new nuclear energy in Poland itself is very competitive in the next decade or two; (2) if such generation could be made available to Poland prior to deployment of its own nuclear generation facilities, Poland would benefit from partnering with its Baltic neighbors to import electricity derived from new nuclear generation facilities sited in Lithuania; and (3) Poland appears to be a good candidate for a partnership in the Global Nuclear Energy Partnership (GNEP) as an emerging nuclear energy country.
Date: March 26, 2007
Creator: Koritarov, V. K.; Conzelmann, G.; Cirillo, R. R. & Goldberg, S. M.
Object Type: Report
System: The UNT Digital Library
Determination of the Evaporation Coefficient of D2O (open access)

Determination of the Evaporation Coefficient of D2O

The evaporation rate of D{sub 2}O has been determined by Raman thermometry of a droplet train (12-15 {micro}m diameter) injected into vacuum ({approx}10{sup -5} torr). The cooling rate measured as a function of time in vacuum was fit to a model that accounts for temperature gradients between the surface and the core of the droplets, yielding an evaporation coefficient ({gamma}{sub e}) of 0.57 {+-} 0.06. This is nearly identical to that found for H{sub 2}O (0.62 {+-} 0.09) using the same experimental method and model, and indicates the existence of a kinetic barrier to evaporation. The application of a recently developed transition state theory (TST) model suggests that the kinetic barrier is due to librational and hindered translational motions at the liquid surface, and that the lack of an isotope effect is due to competing energetic and entropic factors. The implications of these results for cloud and aerosol particles in the atmosphere are discussed.
Date: March 26, 2008
Creator: Drisdell, Walter S.; Cappa, Christopher D.; Smith, Jared D.; Saykally, Richard J. & Cohen, Ronald C.
Object Type: Article
System: The UNT Digital Library
Poland Becoming a Member of the Global Nuclear Energy Partnership, Vol. 2. (open access)

Poland Becoming a Member of the Global Nuclear Energy Partnership, Vol. 2.

Within a constrained carbon environment, the risks of future natural gas supply, and the need to move to market-based electricity prices, the study team found: (1) the deployment of new nuclear energy in Poland itself is very competitive in the next decade or two; (2) if such generation could be made available to Poland prior to deployment of its own nuclear generation facilities, Poland would benefit from partnering with its Baltic neighbors to import electricity derived from new nuclear generation facilities sited in Lithuania; and (3) Poland appears to be a good candidate for a partnership in the Global Nuclear Energy Partnership (GNEP) as an emerging nuclear energy country.
Date: March 26, 2007
Creator: Koritarov, V. K.; Conzelmann, G.; Cirillo, R. R. & Goldberg, S. M.
Object Type: Report
System: The UNT Digital Library
Calibration of the HB line active well neutron coincidence counter for measurement of LANL 3013 highly enriched uranium product splits (open access)

Calibration of the HB line active well neutron coincidence counter for measurement of LANL 3013 highly enriched uranium product splits

None
Date: March 26, 2008
Creator: Dewberry, R.; Williams, D. R.; Lee, R. S.; Roberts, D. W.; Arrigo, L. M. & Salaymeh, S. R.
Object Type: Article
System: The UNT Digital Library
Climate response to projected changes in short-lived species under an A1B scenario from 2000-2050 in the GISS climate model (open access)

Climate response to projected changes in short-lived species under an A1B scenario from 2000-2050 in the GISS climate model

We investigate the climate forcing from and response to projected changes in short-lived species and methane under the A1B scenario from 2000-2050 in the GISS climate model. We present a meta-analysis of new simulations of the full evolution of gas and aerosol species and other existing experiments with variations of the same model. The comparison highlights the importance of several physical processes in determining radiative forcing, especially the effect of climate change on stratosphere-troposphere exchange, heterogeneous sulfate-nitrate-dust chemistry, and changes in methane oxidation and natural emissions. However, the impact of these fairly uncertain physical effects is substantially less than the difference between alternative emission scenarios for all short-lived species. The net global mean annual average direct radiative forcing from the short-lived species is .02 W/m{sup 2} or less in our projections, as substantial positive ozone forcing is largely offset by negative aerosol direct forcing. Since aerosol reductions also lead to a reduced indirect effect, the global mean surface temperature warms by {approx}0.07 C by 2030 and {approx}0.13 C by 2050, adding 19% and 17%, respectively, to the warming induced by long-lived greenhouse gases. Regional direct forcings are large, up to 3.8 W/m{sup 2}. The ensemble-mean climate response shows little regional …
Date: March 26, 2007
Creator: Menon, Surabi; Shindell, Drew T.; Faluvegi, Greg; Bauer, Susanne E.; Koch, Dorothy M.; Unger, Nadine et al.
Object Type: Article
System: The UNT Digital Library
Failure Forewarning in NPP Equipment NERI2000-109 Final Project Report (open access)

Failure Forewarning in NPP Equipment NERI2000-109 Final Project Report

The objective of this project is forewarning of machine failures in critical equipment at next-generation nuclear power plants (NPP). Test data were provided by two collaborating institutions: Duke Engineering and Services (first project year), and the Pennsylvania State University (Applied Research Laboratory) during the second and third project years. New nonlinear methods were developed and applied successfully to extract forewarning trends from process-indicative, time-serial data for timely, condition-based maintenance. Anticipation of failures in critical equipment at next-generation NPP will improve the scheduling of maintenance activities to minimize safety concerns, unscheduled non-productive downtime, and collateral damage due to unexpected failures. This approach provides significant economic benefit, and is expected to improve public acceptance of nuclear power. The approach is a multi-tiered, model-independent, and data-driven analysis that uses ORNL's novel nonlinear method to extract forewarning of machine failures from appropriate data. The first tier of the analysis provides a robust choice for the process-indicative data. The second tier rejects data of inadequate quality. The third tier removes signal artifacts that would otherwise confound the analysis, while retaining the relevant nonlinear dynamics. The fourth tier converts the artifact-filtered time-serial data into a geometric representation, that is then transformed to a discrete distribution function …
Date: March 26, 2004
Creator: Hively, LM
Object Type: Report
System: The UNT Digital Library
Frequency Control Concerns in the North American Electric Power System (open access)

Frequency Control Concerns in the North American Electric Power System

This paper examines the relationship between system frequency, reliability and markets. It was prompted by the frequency deviations recently experienced at 2200 hours daily but is more generally concerned with the question of what frequency control is necessary. The paper does not provide new information or document new research. Nor is it intended to educate readers concerning power system engineering. Instead, the purpose is to reexamine well known truths concerning the power system and to freshly explore the basic relationship between frequency, reliability and markets: stepping back, if you will, to see if we are collectively missing something. The concern of this paper is with frequency and reliability. Off-nominal frequency can impact reliability and markets efficiency (as we are using the term here) in four ways. It could damage equipment (generation, transmission, or load). It could degrade the quality of the product being delivered to end users (too low and lights would flicker unacceptably, for example). It could result in the collapse of the power system itself (by triggering protective system actions, for example). Or it could result in overloading transmission lines as various generators try to restore system frequency impacting markets efficiency. Often these causes operate in concert. Generator …
Date: March 26, 2003
Creator: Kirby, B.J.
Object Type: Report
System: The UNT Digital Library
Feasibility Study for Photovoltaics, Wind, solar Hot Water and Hybrid Systems (open access)

Feasibility Study for Photovoltaics, Wind, solar Hot Water and Hybrid Systems

Southwestern Indian Polytechnic Institute (SIPI) located in Albuquerque New Mexico is a community college that serves American Indians and Alaska Natives. SIPI’s student body represents over 100 Native American Tribes. SIPI completed a renewable energy feasibility study program and established renewable energy hardware on the SIPI campus, which supplements and creates an educational resource to teach renewable energy courses. The SIPI campus is located, and has as student origins, areas, in which power is an issue in remote reservations. The following hardware was installed and integrated into the campus facilities: small wind turbine, large photovoltaic array that is grid-connected, two photovoltaic arrays, one thin film type, and one polycrystalline type, one dual-axis active tracker and one passive tracker, a hot air system for heating a small building, a portable hybrid photovoltaic system for remote power, and a hot water system to preheat water used in the SIPI Child Care facility. Educational curriculum has been developed for two renewable energy courses one being the study of energy production and use, and especially the roles renewable energy forms like solar, wind, geothermal, hydro, and biomass plays, and the second course being a more advanced in-depth study of renewable energy system design, maintenance, …
Date: March 26, 2008
Creator: Hooks, Ronald & Montoya, Valerie
Object Type: Report
System: The UNT Digital Library
Synthesis of Non-molecular Nitrogen Phases at Mbar Pressures by Direct Laser-heating (open access)

Synthesis of Non-molecular Nitrogen Phases at Mbar Pressures by Direct Laser-heating

Direct laser heating of molecular N2 to above 1400 K at 120-130 GPa results in the formation of a reddish amorphous phase and a transparent crystalline solid above 2000 K. Raman and x-ray data confirm that the transparent phase is cubic-gauche nitrogen (cg-N), while the reddish color of the amorphous phase might indicate the presence of N=N dish bonds. The quenched amorphous phase is stable down to at least 70GPa, analogous to cg-N, and could be a new non-molecular phase or an extension of the already known {eta}-phase. A chemo-physical phase diagram is presented which emphasizes the difference between pressure- and temperature-induced transitions from molecular to non-molecular solids, as found in other low Z systems.
Date: March 26, 2007
Creator: Lipp, M. J.; Klepeis, J. P.; Baer, B. J.; Cynn, H.; Evans, W. J.; Iota, V. et al.
Object Type: Article
System: The UNT Digital Library
Studies of Correlated-Electron Systems in High Magnetic Fields and at High Pressures (open access)

Studies of Correlated-Electron Systems in High Magnetic Fields and at High Pressures

None
Date: March 26, 2008
Creator: Cornelius, Dr. Andrew
Object Type: Report
System: The UNT Digital Library
Energy dependence of pi, p and pbar transverse momentum spectra for Au+Au collisions at sqrt sNN = 62.4 and 200 GeV (open access)

Energy dependence of pi, p and pbar transverse momentum spectra for Au+Au collisions at sqrt sNN = 62.4 and 200 GeV

We study the energy dependence of the transverse momentum (pT) spectra for charged pions, protons and anti-protons for Au+Au collisions at sqrt sNN = 62.4 and 200 GeV. Data are presented at mid-rapidity (lbar y rbar< 0.5) for 0.2< pT< 12 GeV/c. In the intermediate pT region (2< pT< 6 GeV/c), the nuclear modification factor is higher at 62.4 GeV than at 200 GeV, while at higher pT (pT> 7 GeV/c) the modification is similar for both energies. The p/pi+ and pbar/pi- ratios for central collisions at sqrt sNN = 62.4 GeV peak at pT _~;; 2 GeV/c. In the pT range where recombination is expected to dominate, the p/pi+ ratios at 62.4 GeV are larger than at 200 GeV, while the pbar/pi- ratios are smaller. For pT> 2 GeV/c, the pbar/pi- ratios at the two beam energies are independent of pT and centrality indicating that the dependence of the pbar/pi- ratio on pT does not change between 62.4 and 200 GeV. These findings challenge various models incorporating jet quenching and/or constituent quark coalescence.
Date: March 26, 2007
Creator: Ritter, H
Object Type: Article
System: The UNT Digital Library
Ab Initio Many-Body Calculations Of n-3H, n-4He, p-3,4He, And n-10Be Scattering (open access)

Ab Initio Many-Body Calculations Of n-3H, n-4He, p-3,4He, And n-10Be Scattering

We develop a new ab initio many-body approach capable of describing simultaneously both bound and scattering states in light nuclei, by combining the resonating-group method with the use of realistic interactions, and a microscopic and consistent description of the nucleon clusters. This approach preserves translational symmetry and Pauli principle. We present phase shifts for neutron scattering on {sup 3}H, {sup 4}He and {sup 10}Be and proton scattering on {sup 3,4}He, using realistic nucleon-nucleon potentials. Our A = 4 scattering results are compared to earlier ab initio calculations. We demonstrate that a proper treatment of the coupling to the n-{sup 10}Be continuum is essential to explain the parity-inverted ground state in {sup 11}Be.
Date: March 26, 2008
Creator: Quaglioni, S & Navratil, P
Object Type: Article
System: The UNT Digital Library