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THE PHENIX EXPERIMENT AT RHIC.
PHENIX is a large detector at the Relativistic Heavy Ion Collider (RHIC) at BNL. RHIC and PHENIX have recently operated for the first time, producing and detecting collisions of gold ions at beam energies of 30 and 65 GeV per nucleon. The current performance and future plans of PHENIX and of RHIC are presented.
Date:
July 27, 2000
Creator:
ARONSON,S. FOR THE PHENIX COLLABORATION
Object Type:
Article
System:
The UNT Digital Library
Preliminary Studies of the Adsorption of Uranium in a Resin-In-Pulp System
Data were obtained in non-flowing and flowing (continuous) batch adsorption systems to serve as a guide to the operating conditions that should be used in a resin-in-pulp adsorption system for the recovery of uranium from ores.
Date:
July 27, 1953
Creator:
Abrams, Charles S. & Kaufman, David
Object Type:
Report
System:
The UNT Digital Library
Analysis and optimization of an adsorption air conditioner for electric vehicle applications
This paper shows an analysis of the applicability of an adsorption system for electric vehicle (EV) air conditioning. Adsorption systems are designed and optimized to provide the required cooling for four combinations of vehicle characteristics and driving cycles. The resulting adsorption systems are compared with vapor compression air conditioners that can satisfy the cooling load. The objective function is the overall system weight, which includes the cooling system weight and the weight of the battery necessary to provide energy for air conditioner operation. The system with the minimum overall weight is considered to be the best. The results show the optimum values of all the variables, as well as temperatures and amounts adsorbed, for the adsorption and desorption processes. The results indicate that, for the conditions analyzed in this paper, vapor compression air conditioners are superior to adsorption systems, not only because they are lighter, but also because they have a higher COP and are more compact.
Date:
July 27, 1994
Creator:
Aceves, S. M.
Object Type:
Article
System:
The UNT Digital Library
Adsorption air conditioner for electric vehicle applications. Revision 1
This paper shows an analysis of the applicability of an adsorption system for electric vehicle (EV) air conditioning. Adsorption systems are designed and optimized to provide the required cooling for four combinations of vehicle characteristics and driving cycles. The resulting adsorption systems are compared with vapor compression air conditioners that can satisfy the cooling load. The objective function is the overall system weight, which includes the cooling system weight and the weight of the battery necessary to provide energy for air conditioner operation. The system with the minimum overall weight is considered to be the best, because a lower weight results in an increased vehicle range. The results indicate that, for the conditions analyzed in this paper, vapor compression air conditioners are superior to adsorption systems not only because they are lighter, but also because they have a higher COP and are more compact.
Date:
July 27, 1994
Creator:
Aceves, S.M.
Object Type:
Article
System:
The UNT Digital Library
Structure and Electronic Properties of Cerium Orthophosphate: Theory and Experiment
Structural and electronic properties of cerium orthophosphate (CePO{sub 4}) are calculated using density functional theory (DFT) with the local spin-density approximation (LSDA+U), with and without gradient corrections (GGA-(PBE)+U), and compared to X-ray diffraction and photoemission spectroscopy measurements. The density of states is found to change significantly as the Hubbard parameter U, which is applied to the Ce 4f states, is varied from 0 to 5 eV. The calculated structural properties are in good agreement with experiment and do not change significantly with U. Choosing U = 3 eV for LDSA provides the best agreement between the calculated density of states and the experimental photoemission spectra.
Date:
July 27, 2010
Creator:
Adelstein, Nicole; Mun, B. Simon; Ray, Hannah; Ross Jr, Phillip; Neaton, Jeffrey & De Jonghe, Lutgard
Object Type:
Article
System:
The UNT Digital Library
Adaptive optics high resolution spectroscopy: present status and future direction
High resolution spectroscopy experiments with visible adaptive optics (AO) telescopes at Starfire Optical Range and Mt. Wilson have demonstrated that spectral resolution can be routinely improved by a factor of - 10 over the seeing-limited case with no extra light losses at visible wavelengths. With large CCDs now available, a very wide wavelength range can be covered in a single exposure. In the near future, most large ground-based telescopes will be equipped with powerful A0 systems. Most of these systems are aimed primarily at diffraction-limited operation in the near IR. An exciting new opportunity will thus open up for high resolution IR spectroscopy. Immersion echelle gratings with much coarser grooves being developed by us at LLNL will play a critical role in achieving high spectral resolution with a compact and low cost IR cryogenically cooled spectrograph and simultaneous large wavelength coverage on relatively small IR detectors. We have constructed a new A0 optimized spectrograph at Steward Observatory to provide R = 200,000 in the optical, which is being commissioned at the Starfire Optical Range 3.5m telescope. We have completed the optical design of the LLNL IR Immersion Spectrograph (LISPEC) to take advantage of improved silicon etching technology. Key words: adaptive …
Date:
July 27, 1999
Creator:
Alcock, C.; Angel, R.; Ciarlo, D.; Fugate, R. O.; Ge, J.; Kuzmenko, P. et al.
Object Type:
Article
System:
The UNT Digital Library
The Gray Wolf and the Endangered Species Act (ESA): A Brief Legal History
This report provides a brief history of the laws, regulations, and lawsuits related to the wolf's protected status.
Date:
July 27, 2011
Creator:
Alexander, Kristina
Object Type:
Report
System:
The UNT Digital Library
Bulk Properties of Iron Isotopes
Nuclear level densities and radiative strength functions (RSF) in {sup 56}Fe and {sup 57}Fe were measured using the {sup 57}Fe({sup 3}He,{alpha}{gamma}) and {sup 57}Fe({sup 3}He, {sup 3}He{prime}{gamma}) reactions, respectively, at Oslo Cyclotron Laboratory. A low-energy enhancement in the RSF below 4 MeV energy was observed. This finding cannot be explained by common theoretical models. In a second experiment, two-step cascade intensities with soft primary transitions from the {sup 56}Fe(n,2{gamma}) reaction were measured. The agreement between the two experiments confirms the low-energy enhancement in the RSF. In a third experiment, the neutron evaporation spectrum from the {sup 55}Mn(dn,N){sup 56}Fe reaction was measured at 7-MeV deuteron energy at John Edwards Accelerator Laboratory at Ohio University. Comparison of the level density of {sup 56}Fe obtained from the first and third experiments gives an overall good agreement. Furthermore, observed enhancement for soft {gamma} rays is supported by the last experiment.
Date:
July 27, 2006
Creator:
Algin, E.; Schiller, A.; Voinov, A.; Agvannluvsan, U.; Belgya, T.; Bernstein, L. et al.
Object Type:
Article
System:
The UNT Digital Library
Highly-Efficient Laser with Self-Aligned Waveguide and Current Confinement by Selective Oxidation
We report highly efficient, low-threshold-current edge-emitting lasers where both the optical waveguide and lateral current confinement are achieved by lateral selective oxidation of AlGaAs. External differential quantum efficiency in excess of 95% and 40% wall-plug efficiency are demonstrated in 600 {micro}m-long devices without facet coatings. Shorter, 300-{micro}m-long, uncoated devices have <6 mA threshold currents. This high-performance is a combined result of placement of the oxide layers so as to achieve the minimum optical mode volume and bi-parabolic grading of the Al{sub x}Ga{sub 1{minus}x}As heteroepitaxy for minimum height/potential barriers, less than 15 meV, created by the wide-energy-gap layers required for selective wet oxidation. Since the initial development of wet AlGaAs oxidation methods, a number of oxidized edge-emitting laser concepts have been tried. The most successful of these have used lateral selective oxidation of AlGaAs layers between 100 and 300 nm thickness. These layers have been used as current restricting apertures or for both current restriction and lateral waveguiding. Use of an oxide layer above and below the laser active region offers the ability to create a self-aligned waveguide with current apertures on both sides of the pn-junction in a process requiring only one epitaxial growth step. Previous use apertures for these …
Date:
July 27, 1999
Creator:
Allerman, A.; Blum, O.; Gao, Y. & Vawter, G. A.
Object Type:
Article
System:
The UNT Digital Library
Bwr Axial Profile
None
Date:
July 27, 2005
Creator:
Alsaed, A.
Object Type:
Report
System:
The UNT Digital Library
ENRICO FERMI FAST REACTOR SPENT NUCLEAR FUEL CRITICALLY CALCULATIONS: INTACT MODE
None
Date:
July 27, 2005
Creator:
Alsaed, A.
Object Type:
Report
System:
The UNT Digital Library
ISOTOPIC MODEL FOR COMMERCIAL SNF BURNUP CREDIT
None
Date:
July 27, 2005
Creator:
Alsaed, A.
Object Type:
Report
System:
The UNT Digital Library
PWR AXIAL BURNUP PROFILE ANALYSIS
None
Date:
July 27, 2005
Creator:
Alsaed, A.
Object Type:
Report
System:
The UNT Digital Library
CONFIGURATION GENERATOR MODEL
None
Date:
July 27, 2005
Creator:
Alsaed, Abdelhalim
Object Type:
Report
System:
The UNT Digital Library
A Numerical Analysis of 3D EM Imaging from a Single Borehole
In this study we analyze the feasibility of three dimensional (3D) electromagnetic (EM) imaging from a single borehole. The proposed logging tool consists of three mutually orthogonal magnetic dipole sources and multiple three component magnetic field receivers. A sensitivity analysis indicates that the most important sensor configuration for providing 3D geological information about the borehole consists of a transmitter with moment aligned parallel to the axis of the borehole, and receivers aligned perpendicular to the axis. The standard coaxial logging configuration provides the greatest depth of sensitivity compared to other configurations, but offers no information regarding 3D structure. Two other tool configurations in which both the source and receiver are aligned perpendicular to the borehole axis provide some directional information and therefore better image resolution, but not true 3D information. A 3D inversion algorithm has been employed to demonstrate the plausibility of 3D inversion using data collected with the proposed logging tool. This study demonstrates that an increase in image resolution results when three orthogonal sources are incorporated into the logging tool rather than a single axially aligned source.
Date:
July 27, 1999
Creator:
Alumbaugh, David L. & Wilt, Michael J.
Object Type:
Article
System:
The UNT Digital Library
Distribution-independent hierarchicald N-body methods
The N-body problem is to simulate the motion of N particles under the influence of mutual force fields based on an inverse square law. The problem has applications in several domains including astrophysics, molecular dynamics, fluid dynamics, radiosity methods in computer graphics and numerical complex analysis. Research efforts have focused on reducing the O(N{sup 2}) time per iteration required by the naive algorithm of computing each pairwise interaction. Widely respected among these are the Barnes-Hut and Greengard methods. Greengard claims his algorithm reduces the complexity to O(N) time per iteration. Throughout this thesis, we concentrate on rigorous, distribution-independent, worst-case analysis of the N-body methods. We show that Greengard`s algorithm is not O(N), as claimed. Both Barnes-Hut and Greengard`s methods depend on the same data structure, which we show is distribution-dependent. For the distribution that results in the smallest running time, we show that Greengard`s algorithm is {Omega}(N log{sup 2} N) in two dimensions and {Omega}(N log{sup 4} N) in three dimensions. We have designed a hierarchical data structure whose size depends entirely upon the number of particles and is independent of the distribution of the particles. We show that both Greengard`s and Barnes-Hut algorithms can be used in conjunction with …
Date:
July 27, 1994
Creator:
Aluru, S.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Feasibility Study for the Development of a Surface Plasmon Resonance spectroscopy-based Sensor for the BNFL-Hanford
The Department of Energy must treat and dispose of large volumes of radioactive waste stored in underground storage tanks at five DOE sites. Technology development has been focused on the separation and removal of various radionuclides from the supernatant contained in the Hanford waste tanks.
Date:
July 27, 2000
Creator:
Anderson, B.B.
Object Type:
Report
System:
The UNT Digital Library
A new atomic mechanism for nuclear isomeric energy release: TE{sup 2}N
In this short note we wish to describe schemes which mix atomic and nuclear energy levels and so permit transfer of nuclear energy to the atomic system from which it is extracted. In addition, we will describe a scheme for stimulating this transfer process which offers the possibility of multi-kilovolt coherent radiation. These ideas are based upon newly available, novel experimental techniques which permit the precise filling of atomic levels and the availability of a broad range of lasers. These new abilities permit the tuning of atomic levels so that they are degenerate or nearly degenerate with nuclear isomeric levels. Such processes permit the exploration of highly leveraged research which could lead to radiation free Ultra High Energy Density Materials in addition to X-Ray Lasers with Gamma ray energies. 2 refs.
Date:
July 27, 1993
Creator:
Anderson, J. D. & Weiss, M. S.
Object Type:
Report
System:
The UNT Digital Library
Catalyst and process development for synthesis gas conversion to isobutylene
A rate equation for carbon monoxide consumption showing first order in CO and 0.5 order in hydrogen indicates the rate controlling step involves dissociated hydrogen. The inhibition of the rate with carbon dioxide is also shown. Examination of the hydrocarbon distributions indicates a see-saw effect with the C[sub 4]s representing the fulcrum and methane and C[sub 5][sup +] the end points. The shift in the distributions tends to be towards the C[sub 5][sup +] for high pressures and long residence times. This distribution can be shifted by incorporating Ti into the catalysts, but the optimum amount of Ti needs to be determined. The sol gel method of preparing the catalysts tends to produce a less active catalyst than by precipitation of a zirconyl salt. The most active catalyst contained approximately 2% Th/ZrO[sub 2]
Date:
July 27, 1992
Creator:
Anthony, R. G. & Akgerman, A.
Object Type:
Report
System:
The UNT Digital Library
Catalyst and process development for synthesis gas conversion to isobutylene. Quarterly report, April 1, 1992--June 30, 1992
A rate equation for carbon monoxide consumption showing first order in CO and 0.5 order in hydrogen indicates the rate controlling step involves dissociated hydrogen. The inhibition of the rate with carbon dioxide is also shown. Examination of the hydrocarbon distributions indicates a see-saw effect with the C{sub 4}s representing the fulcrum and methane and C{sub 5}{sup +} the end points. The shift in the distributions tends to be towards the C{sub 5}{sup +} for high pressures and long residence times. This distribution can be shifted by incorporating Ti into the catalysts, but the optimum amount of Ti needs to be determined. The sol gel method of preparing the catalysts tends to produce a less active catalyst than by precipitation of a zirconyl salt. The most active catalyst contained approximately 2% Th/ZrO{sub 2}
Date:
July 27, 1992
Creator:
Anthony, R. G. & Akgerman, A.
Object Type:
Report
System:
The UNT Digital Library
The 2mrad horizontal crossing angle IR layout for a TeV ILC
The current status of the 2mrad crossing angle layout for the ILC is reviewed. The scheme developed in the UK and France is described and the performance discussed for a TeV machine. Secondly, the scheme developed at SLAC and BNL is then studied and modified for a TeV machine. We find that both schemes can handle the higher energy beam with modifications, and share many common features.
Date:
July 27, 2005
Creator:
Appleby, R.; Angal-Kalinin, D.; /Daresbury; Bambade, P.; Mouton, B.; /Orsay, LAL et al.
Object Type:
Article
System:
The UNT Digital Library
Deployment and Operation of the ES-3100 Type B Shipping Container
The U.S. Department of Energy (DOE) National Nuclear Security Administration (NNSA) is shipping, for disposition purposes, bulk quantities of fissile materials, primarily highly enriched uranium (HEU). The U.S. Department of Transportation (DOT) specification 6M container has been the workhorse for NNSA and many other shippers of radioactive material since the 1980s. However, the 6M does not conform to the packaging requirements in the Code of Federal Regulations (10 CFR 71) and, for that reason, is being phased out for use in the DOE secure transportation system by the end of 2006. BWXT Y-12 developed and licensed the ES-3100 container to replace the DOT 6M. The ES-3100 was certified by the Nuclear Regulatory Commission (NRC) in April 2006. The process of deploying the new package began in June 2005 and is planned to be completed in July 2006. The package will be fully operational and completely replace the DOT 6M at the Y-12 National Security Complex (Y-12) by October 2006. This paper reviews the deployment process and the mock loading station that was installed at National Transportation Research Center (NTRC) of Oak Ridge National Laboratory. Specialized equipment, tools, and instrumentation that support the handling and loading operations of the ES-3100 are …
Date:
July 27, 2006
Creator:
Arbital, J. G. & Tousley, D. R.: Miller, D. B.
Object Type:
Report
System:
The UNT Digital Library
Preliminary report on development of coating for alloy case
Coatings examined were selected industrial finishes reported to have good resistance to corrosion and included epoxy resins reinforced with fiberglass. For screening purposes,this preliminary work was done on commercial sheet Mg to which had been applied a dichromate finish. The coatings were tested for impact resistance, corrosion resistance, abrasion resistance, and thermal shock resistance. Conclusions for further work are outlined.
Date:
July 27, 1956
Creator:
Archibald, P.B.
Object Type:
Report
System:
The UNT Digital Library
Adjustable Hoe
Patent for improvement in "the construction of hoes and to provide a simple, practical, and inexpensive hoe, of strong and durable construction." (lines 11-13) including illustrations.
Date:
July 27, 1915
Creator:
Armstrong, John Joshua, Sr.
Object Type:
Patent
System:
The Portal to Texas History