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open access

Optimizing the Turbo-Roto-Compound (TRC) Engine. Final report

Description: Results of multidimensional computations of sprays in a very high pressure constant volume chamber are presented in two parts. Comparisons of computed and measured penetrations of non-vaporizing and vaporizing sprays are presented. A broad range of density ratios (0.005 to 0.243) is covered. It is shown that, provided sufficient numerical resolution is used, the model can adequately reproduce the measurements. Scaling laws for time and distance derived in a previous publication are found to app… more
Date: August 15, 1994
Creator: Abraham, J.
Partner: UNT Libraries Government Documents Department
open access

Sediment isotope tomography (SIT) model version 1

Description: Geochronology using {sup 210}Pb is the principal method used to quantify sediment accumulation in rapidly depositing aquatic environments such as lakes, estuaries, continental shelves, and submarine canyons. This method is based on the radioactive decay of {sup 210}Pb with depth in a column of sediment. The decay through time of {sup 210}Pb P(t) is governed by the exponential law P(t) = P{sub 0} exp( -{lambda}t) where P{sub 0} is the surficial concentration at time t = 0, and {lambda} is the de… more
Date: March 8, 1996
Creator: Carroll, J. & Abraham, J.D.
Partner: UNT Libraries Government Documents Department

Wedding shoes

Description: Pair of plum purple satin pumps. The shoes are designed with a rounded toe, and plain uppers. The low heel is of a modified Louis or Cuban style, set in, and covered with matching fabric. Partly lined in white kidskin leather. Measurements: Length: 24 cm Width: 7.5cm Height: 10cm Heel: 4cm (1 1/2") high on axis w/cap
Date: 1881
Partner: UNT College of Visual Arts + Design

Pumps

Description: Pair of plum purple satin pumps. The shoes are designed with a rounded toe, and plain uppers. The low heel is of a modified Louis or Cuban style, set in, and covered with matching fabric. Partly lined in white kidskin leather.
Date: 1881~
Partner: UNT College of Visual Arts + Design
open access

High sensitivity, low profile neutron detector for safeguards measurements

Description: A neutron detector has been constructed and tested at Pacific Northwest Laboratory (PNL) for the purpose of making fast, high sensitivity measurements of neutron emitters in portal applications. The system is based upon glass fiber optic scintillators loaded with lithium-6 and operated to detect thermal neutrons. Due to their compact size. physical flexibility, freedom from microphonic pickup, and complete lack of environmental and safety concerns, these fibers are very suitable for some applic… more
Date: December 1, 1993
Creator: Miley, H. S.; Abraham, J. R.; Thompson, R. C. & Sunberg, D. S.
Partner: UNT Libraries Government Documents Department
open access

Real-time, in situ detection of {sup 90}Sr and {sup 238}U in soils via scintillating-fiber-sensor technology

Description: A revolutionary sensor has been developed for observing the highly energetic beta particles that originate from the decay daughters of {sup 238}U and {sup 9O}Sr. This is accomplished through (1) constructing flat ribbons that are each composed of numerous square scintillating fibers, (2) stacking these ribbons and coupling each bundled end to a photomultiplier tube, and (3) using custom-designed electronic circuitry to measure both interlayer and intralayer coincident events. By observing the r… more
Date: May 1, 1994
Creator: Schilk, A. J.; Knopf, M. A.; Thompson, R. C.; Hubbard, C. W.; Abel, K. H.; Edwards, D. R. et al.
Partner: UNT Libraries Government Documents Department
open access

Alpha Channeling in a Rotating Plasma

Description: The wave-particle α-channeling effect is generalized to include rotating plasma. Specifically, radio frequency waves can resonate with α particles in a mirror machine with E × B rotation to diffuse the α particles along constrained paths in phase space. Of major interest is that the α-particle energy, in addition to amplifying the RF waves, can directly enhance the rotation energy which in turn provides additional plasma confinement in centrifugal fusion reactors. An ancillary benefit is the ra… more
Date: September 23, 2008
Creator: Fisch, Abraham J. Fetterman and Nathaniel J.
Partner: UNT Libraries Government Documents Department
open access

The Magnetic Centrifugal Mass Filter

Description: Mass filters using rotating plasmas have been considered for separating nuclear waste and spent nuclear fuel. We propose a new mass filter that utilizes centrifugal and magnetic confinement of ions in a way similar to the asymmetric centrifugal trap. This magnetic centrifugal mass filter is shown to be more proliferation resistant than present technology. This filter is collisional and produces well confined output streams, among other advantages. _______________________________________________… more
Date: August 4, 2011
Creator: Fisch, Abraham J. Fetterman and Nathaniel J.
Partner: UNT Libraries Government Documents Department
open access

Plasma Mass Filters For Nuclear Waste Reprocessing

Description: Practical disposal of nuclear waste requires high-throughput separation techniques. The most dangerous part of nuclear waste is the fission product, which contains the most active and mobile radioisotopes and produces most of the heat. We suggest that the fission products could be separated as a group from nuclear waste using plasma mass filters. Plasmabased processes are well suited to separating nuclear waste, because mass rather than chemical properties are used for separation. A single plas… more
Date: May 26, 2011
Creator: Fetterman, Abraham J. & Fisch, Nathaniel J.
Partner: UNT Libraries Government Documents Department
open access

Wave-Driven Rotation In Centrifugal Mirrors

Description: Centrifugal mirrors use supersonic rotation to provide axial confinement and enhanced stability. Usually the rotation is produced using electrodes, but these electrodes have limited the rotation to the Alfven critical ionization velocity, which is too slow to be useful for fusion. Instead, the rotation could be produced using radio frequency waves. A fixed azimuthal ripple is a simple and efficient wave that could produce rotation by harnessing alpha particle energy. This is an extension of the… more
Date: March 28, 2011
Creator: Fisch, Abraham J. Fetterman and Nathaniel J.
Partner: UNT Libraries Government Documents Department
open access

Metrics For Comparing Plasma Mass Filters

Description: High-throughput mass separation of nuclear waste may be useful for optimal storage, disposal, or environmental remediation. The most dangerous part of nuclear waste is the fission product, which produces most of the heat and medium-term radiation. Plasmas are well-suited to separating nuclear waste because they can separate many different species in a single step. A number of plasma devices have been designed for such mass separation, but there has been no standardized comparison between these … more
Date: August 15, 2012
Creator: Fetterman, Abraham J. & Fisch, Nathaniel J.
Partner: UNT Libraries Government Documents Department
open access

Wave-particle Interactions In Rotating Mirrors

Description: Wave-particle interactions in E×B rotating plasmas feature an unusual effect: particles are diffused by waves in both potential energy and kinetic energy. This wave-particle interaction generalizes the alpha channeling effect, in which radio frequency waves are used to remove alpha particles collisionlessly at low energy. In rotating plasmas, the alpha particles may be removed at low energy through the loss cone, and the energy lost may be transferred to the radial electric field. This eliminat… more
Date: January 11, 2011
Creator: Fisch, Abraham J. Fetterman and Nathaniel J.
Partner: UNT Libraries Government Documents Department
open access

Simulation of Alpha Particles in Rotating Plasma Interacting with a Stationary Ripple

Description: Superthermal ExB rotation can provide magnetohydrodynamic (MHD) stability and enhanced confinement to axisymmetric mirrors. However, the rotation speed has been limited by phenomena at end electrodes. A new prediction is that rotation might instead be produced using a magnetic ripple and alpha particle kinetic energy, in an extension of the alpha channeling concept. The interaction of alpha particles with the ripple results in visually interesting and practically useful orbits.
Date: January 11, 2011
Creator: Fetterman, Abraham J. & Fisch, Nathaniel J.
Partner: UNT Libraries Government Documents Department
open access

Correlation of the highest energy cosmic rays with nearby extragalactic objects

Description: Using data collected at the Pierre Auger Observatory during the past 3.7 years, we demonstrate that there is a correlation between the arrival directions of cosmic rays with energy above {approx} 6 x 10{sup 19} eV and the positions of active galactic nuclei (AGN) lying within {approx} 75 Mpc. We reject the hypothesis of an isotropic distribution of these cosmic rays at over 99% confidence level from a prescribed a priori test. The correlation we observe is compatible with the hypothesis that th… more
Date: November 1, 2007
Creator: Abraham, J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Allard, D.; Allekotte, I. et al.
Partner: UNT Libraries Government Documents Department
open access

Measurement of the Depth of Maximum of Extensive Air Showers above 10^18 eV

Description: We describe the measurement of the depth of maximum, X{sub max}, of the longitudinal development of air showers induced by cosmic rays. Almost 4000 events above 10{sup 18} eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106{sub -21}{sup +35}) g/cm{sup 2}/decade below 10{sup 18.24 {+-} 0.05}eV, and (24 {+-} 3) g… more
Date: February 1, 2010
Creator: Abraham, J.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Allard, D.; Allekotte, I. et al.
Partner: UNT Libraries Government Documents Department
open access

Water potential and starvation stress in deep subsurface microorganisms

Description: Nine intact core samples, collected aseptically from depths of 10--436 m near the Savannah River Plant in South Carolina, were tested for water potential, microbial numbers, and microbial activity. Although all samples were collected from below the water table, two samples (a Pee Dee clay from 238 m and a Middendorf clay from 324 m) showed unsaturated conditions ({minus}2.7 and {minus}2.1 MPa, respectively). Both of these samples had very low numbers of culturable cells, low microbial biomass (… more
Date: December 31, 1990
Creator: Kieft, Thomas L.; Rosacker, Laurie L.; Willcox, David & Franklin, Abraham J.
Partner: UNT Libraries Government Documents Department
open access

Water Potential and Starvation Stress in Deep Subsurface Microorganisms

Description: Nine intact core samples, collected aseptically from depths of 10--436 m near the Savannah River Plant in South Carolina, were tested for water potential, microbial numbers, and microbial activity. Although all samples were collected from below the water table, two samples (a Pee Dee clay from 238 m and a Middendorf clay from 324 m) showed unsaturated conditions ({minus}2.7 and {minus}2.1 MPa, respectively). Both of these samples had very low numbers of culturable cells, low microbial biomass (… more
Date: January 1, 1990
Creator: Kieft, Thomas L.; Rosacker, Laurie L.; Willcox, David & Franklin, Abraham J.
Partner: UNT Libraries Government Documents Department
open access

Contained Modes In Mirrors With Sheared Rotation

Description: In mirrors with E × B rotation, a fixed azimuthal perturbation in the lab frame can appear as a wave in the rotating frame. If the rotation frequency varies with radius, the plasma-frame wave frequency will also vary radially due to the Doppler shift. A wave that propagates in the high rotation plasma region might therefore be evanescent at the plasma edge. This can lead to radially localized Alfven eigenmodes with high azimuthal mode numbers. Contained Alfven modes are found both for peaked an… more
Date: October 8, 2010
Creator: Fetterman, Abraham J.
Partner: UNT Libraries Government Documents Department
open access

An upper limit to the photon fraction in cosmic rays above 10**19-eV from the Pierre Auger Observatory

Description: An upper limit of 16% (at 95% c.l.) is derived for the photon fraction in cosmic rays with energies above 10{sup 19} eV, based on observations of the depth of shower maximum performed with the hybrid detector of the Pierre Auger Observatory. This is the first such limit on photons obtained by observing the fluorescence light profile of air showers. This upper limit confirms and improves on previous results from the Haverah Park and AGASA surface arrays. Additional data recorded with the Auger s… more
Date: June 1, 2006
Creator: Abraham, J.; Aglietta, M.; Aguirre, C.; Allard, D.; Allekotte, I.; Allison, P. et al.
Partner: UNT Libraries Government Documents Department
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