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Implementation of MP{_}Lite for the VI Architecture

Description: MP{_}Lite is a light weight message-passing library designed to deliver the maximum performance to applications in a portable and user friendly manner. The Virtual Interface (VI) architecture is a user-level communication protocol that bypasses the operating system to provide much better performance than traditional network architectures. By combining the high efficiency of MP{_}Lite and high performance of the VI architecture, they are able to implement a high performance message-passing libra… more
Date: December 31, 2002
Creator: Chen, Weiyi
Partner: UNT Libraries Government Documents Department
open access

Phenomenological and mathematical modeling of a high pressure steam driven jet injector. Part 2

Description: An injector is a particular type of jet pump which uses condensable vapor to entrain a liquid and discharge against a pressure higher than either motive or suction pressures. The injector has no moving parts and requires no external power supply nor any complex control system. Thus, the injector is particularly suited for emergency core cooling operations. A detailed survey has indicated that various injector designs are available for operating pressures below 250 psig. However, the design of t… more
Date: December 31, 1993
Creator: Anand, G.
Partner: UNT Libraries Government Documents Department
open access

The Dopants and Doping Level Dependence of the Structure and Magnetic Properties of the Eu (BA1-xLRx)2Cu3O7+Theta

Description: Eu(Ba{sub 1-x}Nd{sub x}){sub 2}Cu{sub 3}O{sub 7+{delta}} were systematically studied in order to understand how the valence of the rear earth elements, ionic sizes and magnetic moment affect the crystal structure and magnetic and electrical properties. Differential thermal analyses were carried out to check the phase purity, X-ray data were least-squares fitted to determine the lattice parameters, and DC-SQUID magnetometry was used to characterize the superconducting properties. These results s… more
Date: December 31, 2002
Creator: Lin, Yu
Partner: UNT Libraries Government Documents Department
open access

A Compton scatter camera for spectral imaging of 0.5 to 3.0 MeV gamma rays

Description: A prototype Compton scatter camera for imaging gamma rays has been built and tested. This camera addresses unique aspects of gamma-ray imaging at nuclear industrial sites, including gamma-ray energies in the 0.5 to 3.0 MeV range and polychromatic fields. Analytic models of camera efficiency, resolution and contaminating events are developed. The response of the camera bears strong similarity to emission computed tomography devices used in nuclear medicine. A direct Fourier based algorithm is de… more
Date: December 31, 1994
Creator: Martin, J.B.
Partner: UNT Libraries Government Documents Department
open access

Study of Pion-Pion Scattering from the Reaction $pi$$sup +$ + p $Yields$ $pi$$sup +$ + $pi$$sup +$ + n AT 1.25 AND 1.75 Bev/c

Description: The equipment and procedure used in measuring the distribution of energy and angle of recoil of neutrons from the reaction pi /sup +/ + p yields pi / sup +/ + pi /sup +/ + n for incident pion mome nta of 1.25 and 1.75 Bev/c are explained. Utilization of the plastic scintillator detectors is given particular attention. Data on the cross section for pion-pion scattering are presented and analyzed. (22 references.) (D.C.W.)
Date: October 31, 1962
Creator: Auerbach, L. B.
Partner: UNT Libraries Government Documents Department
open access

A study of radon-222 concentrations in North Carolina groundwater

Description: The groundwater of 400 North Carolina homes was sampled to ascertain the distribution and extent of {sup 222}Rn in North Carolina groundwater. Arithmetic mean (AM) and geometric mean (GM) concentrations of 1,816 pCi L{sup {minus}1} and 656 pCi L{sup {minus}1} were found for the state. These results indicate that two-thirds of 114{degree}C. homes served by groundwater exceed the EPA proposed 300 pCi L{sup {minus}1} maximum contaminant level (MCL). Only 2% of NC homes exceeded 10,000 pCi L-1. The… more
Date: December 31, 1992
Creator: Evans, J. P.
Partner: UNT Libraries Government Documents Department
open access

Direct {anti b}b production in {anti p}p collisions at {radical}s = 1.8 TeV

Description: The first measurement of bottom quark production in the forward detector at CDF is presented in this thesis. Events from the 1988/89 Fermilab collider run were selected with forward muons with nearby jets to form a bottom quark tag. The efficiency and acceptance of the detector are then taken into account and the number of events is turned into a cross section: {sigma}(p{sub t}{sup b} > 20 GeV, 1.9 < {vert_bar}{eta}{sup b}{vert_bar} < 2.5) = (124. {+-} 35. {+-} 76.) nb. The contribution from di… more
Date: December 31, 1993
Creator: Lamoureux, J.
Partner: UNT Libraries Government Documents Department
open access

Ion sensitive field effect transistors applied to the measurement of the pH of brines

Description: The ability to measure the pH (the negative logarithm of the hydrogen ion activity) of harsh fluids such as geothermal oil field brines is important, since pH is a fundamental property; as one chemist stated: ``very often pH is a critical test because its accuracy lays the foundation for other measurements``. In our research, we focus on the analysis of brines similar to those found in underground geothermal reservoirs. Since the brines are deep under the ground, the values of the pressure and … more
Date: December 31, 1991
Creator: Chen, J.
Partner: UNT Libraries Government Documents Department
open access

Laser Processing of Metals and Polymers

Description: A laser offers a unique set of opportunities for precise delivery of high quality coherent energy. This energy can be tailored to alter the properties of material allowing a very flexible adjustment of the interaction that can lead to melting, vaporization, or just surface modification. Nowadays laser systems can be found in nearly all branches of research and industry for numerous applications. Sufficient evidence exists in the literature to suggest that further advancements in the field of la… more
Date: May 31, 2012
Creator: Singaravelu, Senthilraja
Partner: UNT Libraries Government Documents Department
open access

Meausrement of the Neutron Radius of {sup 208}Pb Through Parity Violation in Electron Scattering

Description: In contrast to the nuclear charge densities, which have been accurately measured with electron scattering, the knowledge of neutron densities still lack precision. Previous model-dependent hadron experiments suggest the difference between the neutron radius, R{sub n}, of a heavy nucleus and the proton radius, R{sub p}, to be in the order of several percent. To accurately obtain the difference, R{sub n}-R{sub p}, which is essentially a neutron skin, the Jefferson Lab Lead ({sup 208}Pb) Radius Ex… more
Date: May 31, 2013
Creator: Saenboonruang, Kiadtisak
Partner: UNT Libraries Government Documents Department
open access

Beam Size Measurement by Optical Diffraction Radiation and Laser System for Compton Polarimeter

Description: Beam diagnostics is an essential constituent of any accelerator, so that it is named as &quot;organs of sense&quot; or &quot;eyes of the accelerator.&quot; Beam diagnostics is a rich field. A great variety of physical effects or physical principles are made use of in this field. Some devices are based on electro-magnetic influence by moving charges, such as faraday cups, beam transformers, pick-ups; Some are related to Coulomb interaction of charged particles with matter, such as scintillators,… more
Date: December 31, 2012
Creator: Liu, Chuyu
Partner: UNT Libraries Government Documents Department
open access

Cooling of highly charged ions in a Penning trap

Description: Highly charged ions are extracted from an electron beam ion trap and guided to Retrap, a cryogenic Penning trap, where they are merged with laser cooled Be{sup +} ions. The Be{sup +} ions act as a coolant for the hot highly charged ions and their temperature is dropped by about 8 orders of magnitude in a few seconds. Such cold highly charged ions form a strongly coupled nonneutral plasma exhibiting, under such conditions, the aggregation of clusters and crystals. Given the right mixture, these … more
Date: March 31, 2000
Creator: Gruber, L
Partner: UNT Libraries Government Documents Department
open access

Transverse liquid fuel jet breakup, burning, and ignition

Description: An analytical/numerical study of the breakup, burning, and ignition of liquid fuels injected transversely into a hot air stream is conducted. The non-reacting liquid jet breakup location is determined by the local sonic point criterion first proposed by Schetz, et al. (1980). Two models, one employing analysis of an elliptical jet cross-section and the other employing a two-dimensional blunt body to represent the transverse jet, have been used for sonic point calculations. An auxiliary criterio… more
Date: December 31, 1990
Creator: Li, H.
Partner: UNT Libraries Government Documents Department
open access

A measurement of the forward-backward asymmetry and sin{sup 2}{theta}{sub W} from the process Z{sup 0} {yields} {mu}{sup +}{mu}{sup {minus}} at {radical}s = 1.8 TeV

Description: A measurement of the forward-backward charge asymmetry in the decay of Z{sup o} bosons produced from {bar p}p collisions at {radical}s = 1.8 TeV at the Fermilab Tevatron collider, and decaying to {mu}{sup +} {mu}{sup {minus}} pairs is presented. From this asymmetry, a value for the Weinburg angle, sin{sup 2} {theta}{sub W}, is extracted and compared to values from other experiments.
Date: December 31, 1992
Creator: Markosky, L. A.
Partner: UNT Libraries Government Documents Department
open access

Atom Probe Field Ion Microscope

Description: This report addresses the design and performance of the atom probe field ion microscope.
Date: October 31, 1971
Creator: Stolt, K. G.
Partner: UNT Libraries Government Documents Department
open access

Mode coupling of electron plasma waves

Description: The driven coupled mode equations are derived for a two fluid, unequal temperature (T/sub e/ much greater than T/sub i/) plasma in the one-dimensional, electrostatic model and applied to the coupling of electron plasma waves. It is assumed that the electron to ion mass ratio identical with m/sub e/M/sub i// much less than 1 and eta$sup 2$/sub ko/k lambda/sub De/ less than 1 where eta$sup 2$/ sub ko/ is the pump wave's power normalized to the plasma thermal energy, k the mode wave number and lam… more
Date: October 31, 1975
Creator: Harte, J.A.
Partner: UNT Libraries Government Documents Department
open access

Measurement of the 3He Spin Structure Functions in the Resonance Region: A Test of Quark-Hadron Duality on the Neutron

Description: One of the biggest challenges in the study of the nucleon structure is the understanding of the transition from partonic degrees of freedom to hadronic degrees of freedom. In 1970, Bloom and Gilman noticed that structure function data taken at SLAC in the resonance region average to the scaling curve of deep inelastic scattering (DIS). Early theoretical interpretations suggested that these two very different regimes can be linked under the condition that the quark-gluon and quark-quark interact… more
Date: August 31, 2006
Creator: Solvignon, Patricia
Partner: UNT Libraries Government Documents Department
open access

Polarisation Transfer in Proton Compton Scattering at High Momentum Transfer

Description: The Jefferson Lab Hall A experiment E99-114 comprised a series of measurements to explore proton Compton scattering at high momentum transfer. For the first time, the polarisation transfer observables in the p (~ 0 ~ p) reaction were measured in the GeV energy range, where it is believed that quark-gluon degrees of freedom begin to dominate. The experiment utilised a circularly polarised photon beam incident on a liquid hydrogen target, with the scattered photon and recoil proton detected in a … more
Date: December 31, 2004
Creator: Hamilton, David
Partner: UNT Libraries Government Documents Department
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