Science and art in heavy-ion collisions (open access)

Science and art in heavy-ion collisions

One of the more intriguing phenomena discovered in heavy-ion physics is the seeming appearance of high energy structure in the excitation spectra of inelastically scattered heavy ions. For reasons illustrated, these may well be a phenomena unique to heavy ions and their explanation perhaps unique to TDHF.
Date: August 9, 1982
Creator: Weiss, M.S.
Object Type: Article
System: The UNT Digital Library
Mild coal gasification: Product separation, pilot-unit support, twin screw heat transfer, and H sub 2 S evolution (open access)

Mild coal gasification: Product separation, pilot-unit support, twin screw heat transfer, and H sub 2 S evolution

Our general objective is to further the development of efficient continuous mild coal gasification processes. Our efforts this year have been in four main areas. A new thrust has been to identify and develop efficient processes to separate the vapor product stream into particulate-free liquid and mist-free gas. We continued work aimed at predicting heat transfer rates (hence throughput) in externally-heated twin-screw pyrolyzers. We sought to provide technical support for the design, installation, startup, and operation of the DOE-sponsored 500 kg/hr twin-screw mild gasification unit at Coal Technology Corporation (CTC). A smaller laboratory effort had the objective of identifying and testing the reaction mechanisms of sulfur species during coal pyrolysis. Detailed subproject objectives are given in their respective sections. 20 refs., 4 figs., 1 tab.
Date: August 9, 1991
Creator: Camp, D. W.; Wallman, P. H. & Coburn, T. T.
Object Type: Article
System: The UNT Digital Library
Evaluation of the photochemical production of hydrogen from solar energy (open access)

Evaluation of the photochemical production of hydrogen from solar energy

The potential for utilizing solar energy through photochemical storage were investigated. Both water and nitrosyl chloride systems are examined. A comprehensive review of the literature led to the conclusion that many major questions must be answered before photochemical energy storage becomes a viable alternate means of exploiting solar energy.
Date: August 9, 1977
Creator: Heppert, J. A.
Object Type: Report
System: The UNT Digital Library
The theory of heavy flavour production (open access)

The theory of heavy flavour production

The theory of heavy quark production in hadronic reactions is reviewed. Rates for the production of charm, bottom and top quarks at energies of current interest are presented. 34 refs., 19 figs., 2 tabs.
Date: August 9, 1989
Creator: Ellis, R.K.
Object Type: Article
System: The UNT Digital Library
Conversion of administration buildings entry to a greenhouse. Final status report (open access)

Conversion of administration buildings entry to a greenhouse. Final status report

A project is briefly described that was to convert an administration building's entry to a greenhouse. The plan calls for extra insulation, a Trombe wall, berming, and double-glazed window units. The social and economic benefits of the project and qualifications of key people are listed. (LEW)
Date: August 9, 1982
Creator: Nolan, A.H.
Object Type: Report
System: The UNT Digital Library
SQUID-Detected MRI at 132 Microtesla with T1 Contrast Weighted at10 Microtelsa-300 mT (open access)

SQUID-Detected MRI at 132 Microtesla with T1 Contrast Weighted at10 Microtelsa-300 mT

None
Date: August 9, 2004
Creator: Lee, SeungKyun; Moessle, Michael; Myers, Whittier; Kelso, Nathan; Trabesinger, Andreas H.; Pines, Alex et al.
Object Type: Article
System: The UNT Digital Library
Nevada Test Site Radiation Protection Program (open access)

Nevada Test Site Radiation Protection Program

Title 10 Code of Federal Regulations (CFR) 835, 'Occupational Radiation Protection', establishes radiation protection standards, limits, and program requirements for protecting individuals from ionizing radiation resulting from the conduct of U.S. Department of Energy (DOE) activities. 10 CFR 835.101(a) mandates that DOE activities be conducted in compliance with a documented Radiation Protection Program (RPP) as approved by DOE. This document promulgates the RPP for the Nevada Test Site (NTS), related (onsite or offsite) DOE National Nuclear Security Administration Nevada Site Office (NNSA/NSO) operations, and environmental restoration offsite projects.
Date: August 9, 2007
Creator: Radiological Control Managers' Council, Nevada Test Site
Object Type: Report
System: The UNT Digital Library
ICDP Complex Groundwater Monitoring Plan REV 5 (open access)

ICDP Complex Groundwater Monitoring Plan REV 5

This Groundwater Monitoring Plan, along with the Quality Assurance Project Plan for Waste Area Groups 1, 2, 3, 4, 5, 6, 7, 10, and Removal Actions, constitutes the sampling and analysis plan for groundwater and perched water monitoring at the Idaho CERCLA Disposal Facility (ICDF). A detection monitoring system was installed in the Snake River Plan Aquifer to comply with substantive requirements of "Releases from Solid Waste Management Units" of the Resource Conservation and Recovery Act. This detection monitoring wells constructed in the Snake River Plain Aquifer.
Date: August 9, 2007
Creator: Cahn, L. S.
Object Type: Report
System: The UNT Digital Library
On Some Versions of the Element Agglomeration AMGe Method (open access)

On Some Versions of the Element Agglomeration AMGe Method

The present paper deals with element-based AMG methods that target linear systems of equations coming from finite element discretizations of elliptic PDEs. The individual element information (element matrices and element topology) is the main input to construct the AMG hierarchy. We study a number of variants of the spectral agglomerate element based AMG method. The core of the algorithms relies on element agglomeration utilizing the element topology (built recursively from fine to coarse levels). The actual selection of the coarse degrees of freedom (dofs) is based on solving large number of local eigenvalue problems. Additionally, we investigate strategies for adaptive AMG as well as multigrid cycles that are more expensive than the V-cycle utilizing simple interpolation matrices and nested conjugate gradient (CG) based recursive calls between the levels. The presented algorithms are illustrated with an extensive set of experiments based on a matlab implementation of the methods.
Date: August 9, 2007
Creator: Lashuk, I & Vassilevski, P
Object Type: Article
System: The UNT Digital Library
Neutron Production from Feedback Controlled Thermal Cycling of a Pyroelectric Crystal Stack (open access)

Neutron Production from Feedback Controlled Thermal Cycling of a Pyroelectric Crystal Stack

The LLNL Crystal Driven Neutron Source is operational and has produced record ion currents of {approx}10 nA and neutron output of 1.9 ({+-}0.3) x 10{sup 5} per thermal cycle using a crystal heating rate of 0.2 C/s from 10 C to 110 C. A 3 cm diameter by 1 cm thick LiTaO{sub 3} crystal with a socket secured field emitter tip is thermally cycled with feedback control for ionization and acceleration of deuterons onto a deuterated target to produce D-D fusion neutrons. The entire crystal and temperature system is mounted on a bellows which allows movement of the crystal along the beam axis and is completely contained on a single small vacuum flange. The modular crystal assembly permitted experimental flexibility. Operationally, flashover breakdowns along the side of the crystal and poor emitter tip characteristics can limit the neutron source. The experimental neutron results extend earlier published work by increasing the ion current and pulse length significantly to achieve a factor-of-two higher neutron output per thermal cycle. These findings are reviewed along with details of the instrument.
Date: August 9, 2007
Creator: Tang, V; Meyer, G; Schmid, G; Spadaccini, C; Kerr, P; Rusnak, B et al.
Object Type: Article
System: The UNT Digital Library
Seeded Growth of Highly Luminescent CdSe/CdS Nano-Heterostructures with Rod and Tetrapod Morphologies (open access)

Seeded Growth of Highly Luminescent CdSe/CdS Nano-Heterostructures with Rod and Tetrapod Morphologies

We have demonstrated that seeded growth of nanocrystals offers a convenient way to design nanoheterostructures with complex shapes and morphologies by changing the crystalline structure of the seed. By using Use nanocrystals with wurtzite and zinc blende structure as seeds for growth of US nanorods, we synthesized CdSe/CdS heterostructure nanorods and nanotetrapods, respectively. Both of these structures showed excellent luminescentproperties, combining high photoluminescence efficiency (similar to 80 and similar to 50percent for nanorods and nanotetrapods, correspondingly), giant extinction coefficients (similar to 2 x 10(7) and similar to 1.5 x 10(8) M-1 cm (-1) at 350 nm for nanorods and nanotetrapods, correspondingly), and efficient energy transfer from the US arms into the emitting CdSe Core.
Date: August 9, 2007
Creator: Talapin, Dmitri; Talapin, Dmitri V.; Nelson, James H.; Shevchenko, Elena V.; Aloni, Shaul; Sadtler, Bryce et al.
Object Type: Article
System: The UNT Digital Library
Enantiopure, Octadentate Ligands as Sensitizers for Europium andTerbium Circularly Polarized Luminescence in Aqueous Solution (open access)

Enantiopure, Octadentate Ligands as Sensitizers for Europium andTerbium Circularly Polarized Luminescence in Aqueous Solution

Tb and Eu complexes of enantiopure ligands with a new modular design show strong overall luminescence and CPL activity in aqueous solution.
Date: August 9, 2007
Creator: Seitz, Michael; Moore, Evan G.; Ingram, Andrew J.; Muller,Gilles & Raymond, Kenneth N.
Object Type: Article
System: The UNT Digital Library
Look at energy compression as an assist for high power rf production (open access)

Look at energy compression as an assist for high power rf production

The desire to construct electron linacs of higher and higher energies, coupled with the realities of available funding and real estate, has forced machine designers to reassess the limitations in both accelerator gradient (MeV/m) and energy. The gradients achieved in current radio-frequency (RF) linacs are sometimes set by electrical breakdown in the accelerating structure, but are in most cases determined by the RF power level available to drive the linac. In this paper we will not discuss RF power sources in general, but rather take a brief look at several energy compression schemes which might be of service in helping to make better use of the sources we employ. We will, however, diverge for a bit and discuss what the RF power requirements are. 12 references, 21 figures, 3 tables.
Date: August 9, 1984
Creator: Birx, D. L.; Farkas, Z. D. & Wilson, P. B.
Object Type: Article
System: The UNT Digital Library
JUPITER-II Program: ANL analysis of ZPPR-13A and ZPPR-13B (open access)

JUPITER-II Program: ANL analysis of ZPPR-13A and ZPPR-13B

The ZPPR-13 experiments provide basic physics data for radial-heterogeneous LMFBR cores of approximately 700 MWe size. Assemblies ZPPR-13A, ZPPR-13B and ZPPR-13C comprised the JUPITER-II cooperative program between US-DOE and PNC of Japan. The measurements were made between August 1982 and April 1984. This report describes in detail the results of the ANL analyses of phases 13A and 13B/1 and includes preliminary results for the later assemblies of phase 13B. The data were compiled primarily for discussions at the Third Jupiter Analysis Meeting to be held at ANL-West between September 11th and 14th, 1984.
Date: August 9, 1984
Creator: Collins, P.J. & Brumbach, S.B. (comps.)
Object Type: Report
System: The UNT Digital Library
Theory and simulation of laser plasma coupling (open access)

Theory and simulation of laser plasma coupling

The theory and simulation of these coupling processes are considered. Particular emphasis is given to their nonlinear evolution. First a brief introduction to computer simulation of plasmas using particle codes is given. Then the absorption of light via the generation of plasma waves is considered, followed by a discussion of stimulated scattering of intense light. Finally these calculations are compared with experimental results.
Date: August 9, 1979
Creator: Kruer, W.L.
Object Type: Report
System: The UNT Digital Library
How to search for an electric dipole form factor of the. tau. lepton at a. tau. -charm factory (open access)

How to search for an electric dipole form factor of the. tau. lepton at a. tau. -charm factory

We investigate some CP-odd correlations which can be used to search for an electric dipole form factor d{sub {tau}}(s) of the {tau} in the reaction e{sup +}e{sup {minus}} {yields} {tau}{sup +}{tau} {sup {minus}} at c.m. energies {radical}s relevant for a {tau}-charm factory. These observables require measurement of the {tau} polarizations. Using the channel e{sup +}e{sup {minus}} {yields} {pi}{sup +} {nu}{sub {tau}}{pi}{sup {minus}}{nu}{sub {tau}} one should be able to measure d{sub {tau}} at {radical}s = 4 GeV with an accuracy {delta}(d{sub {tau}}) {approx equal} 2.5 {times} 10{sup {minus}16}e cm, assuming the production of 10{sup 7} {tau} pairs. The same accuracy can be reached with 10{sup 6} {tau} pairs at {radical}s = 10 GeV, the typical c.m. energy of a B-factory. 8 refs., 2 figs., 1 tab.
Date: August 9, 1989
Creator: Bernreuther, W. (Lawrence Berkeley Lab., CA (USA)) & Nachtmann, O. (Heidelberg Univ. (Germany, F.R.) Stanford Linear Accelerator Center, Menlo Park, CA (USA))
Object Type: Article
System: The UNT Digital Library
Full scale demonstration of low-NO sub x cell burner retrofit (open access)

Full scale demonstration of low-NO sub x cell burner retrofit

The overall objective of the Full-Scale Demonstration of Low-NO{sub x} Cell Burner Retrofit project is to demonstrate the cost-effective reduction of NO{sub x} generated by a large based-loaded (70% capacity factor or greater), coal-fired utility boiler. Specific objectives include: (1) At least 50% NO{sub x} reduction over standard two-nozzle cell burners, without degradation of boiler performance or life; (2) Acquire and evaluate emission and boiler performance data before and after the retrofit to determine NO{sub x} reduction and impact on overall boiler performance; (3) Demonstrate that the retrofit of Low-NO{sub x} Cell Burners in boilers currently equipped with cell burners, is a cost-effective alternative to any other emerging, or commercially-available, NO{sub x} control technology.
Date: August 9, 1991
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Cadmium sulfide/copper sulfide heterojunction cell research. Technical progress report No. 2, January 1--March 31, 1978 (open access)

Cadmium sulfide/copper sulfide heterojunction cell research. Technical progress report No. 2, January 1--March 31, 1978

Poor adhesion of CdS films to zinc-plated copper foil substrates has been eliminated by depositing somewhat thinner films than earlier and by using the mat (as opposed to the smooth) side of the electroformed copper foil for deposition. Particle spatter effects have been reduced and cells of 4 cm/sup 2/ area have been produced with average efficiency of 5.4%. Use of Zn--plated Cu, Mo, Zn--plated Mo and glass substrates appears to influence the etching behavior of CdS films in dilute chromic acid. The results suggest a sensitivity to the presence of zinc. Laser scanned reflection and photocurrent response studies reveal some influence of substrate morphology. Direct correlations are weak, presumably because of strong local variations in topography, due to texturing and in carrier transport or junction collection efficiency. Similar types of studies on single crystal-based cells have established the feasibility of using localized photoresponse to characterize minority carrier transport in special test structures. Compositional analysis of Cu/sub 2/S layers on single crystal CdS have been attempted using ESCA and ion etching methods. A major problem is the formation of copper nodules, presumably due to the ion etching method, which do not permit obtaining a true profile of this element. Films …
Date: August 9, 1978
Creator: Szedon, J. R.; Shirland, F. A. & Biter, W. J.
Object Type: Report
System: The UNT Digital Library
Formation of toroidal plasma confinement configurations by using hot electrons (open access)

Formation of toroidal plasma confinement configurations by using hot electrons

Two possible means are described for producing closed, toroidal pinch-like configurations with hot electrons starting from a microwave-heated, hot electron plasma confined in open fields. The final configurations are directly related to Spheromak and Tormac.
Date: August 9, 1979
Creator: Hartman, C. W.
Object Type: Report
System: The UNT Digital Library
Effect of DOP heterodispersion on HEPA-filter-penetration measurements (open access)

Effect of DOP heterodispersion on HEPA-filter-penetration measurements

The accuracy of the standard US test method for certifying High-Efficiency Particulate Air (HEPA) filters has been in question since the finding by Hinds, et al. that the dioctyl phthalate (DOP) aerosol used in the test is not monodisperse as had been assumed and that particle-size analyzers, or owls, could not distinguish between different particle-size distributions with the same owl reading. We have studied theoretically and experimentally the filter efficiency for different DOP size distributions with the same owl reading. Our studies show that the effect of varying DOP size distributions on the measured HEPA-filter penetration depends on the light-scattering-photometer response and on the HEPA-filter penetration curve, both measured as a function of particle size. HEPA-filter penetration for a heterodisperse DOP aerosol may be increased, decreased, or remain the same when compared to the filter penetration for monodisperse aerosols. Using experimental HEPA-filter penetration and photometer response curves, we show that heterodisperse DOP aerosols (D/sub cmd/ 0.19 and sigma g = 1.4) yield 24% lower penetrations than that for monodisperse DOP aerosols (D/sub cmd/ = 0.3 and sigma g = 1.0). This surprisingly small effect of the DOP heterodispersion on HEPA-filter penetration is due to the response function of the owl …
Date: August 9, 1984
Creator: Bergman, W. & Biermann, A.
Object Type: Report
System: The UNT Digital Library
Nuclear waste-form risk assessment for US defense waste at Savannah River Plant. Annual report FY, 1982 (open access)

Nuclear waste-form risk assessment for US defense waste at Savannah River Plant. Annual report FY, 1982

A network model was developed to simulate the hydrological flow and the transport of radionuclides from a deep geological repository to the biosphere subsequent to closure. By means of very efficient computational methods for solving the fundamental differential equations, a code was developed to treat in great detail the effects of waste form characteristics and of repository designs on the repository risks. It is possible to examine near field effects heretofore not attempted. Without sacrificing the essential details of description, the code can also be applied to perform probabilistic risk analyses to high confidence levels. Analytical results showed: (1) for waste form release rates greater than approximately 5 x 10/sup -7//yr, dose to man is insensitive to release rate and release rate uncertainty; (2) significant reduction in dose can be achieved through simple design modifications; (3) a basalt repository generally does not perform as well as a salt repository; and (4) disruptive events are relatively unimportant for repository safety. 82 references.
Date: August 9, 1982
Creator: Cheung, H.; Edwards, L. L. & Harvey, T. F.
Object Type: Report
System: The UNT Digital Library
Literature survey of isotopic abundance data for 1987-1989 (open access)

Literature survey of isotopic abundance data for 1987-1989

I have compiled all of the data on isotopic abundance measurements and their variation in nature for the time period since the last General Assembly. Most of the data deals with the variations in the abundances as given by per mil deviations from some standard. As such, they are not of major interest to the Atomic Weights Commission. However, there were some measurements which are of general interest in this list.
Date: August 9, 1989
Creator: Holden, N.E. (Brookhaven National Lab., Upton, NY (USA))
Object Type: Article
System: The UNT Digital Library
Numerical algorithms in chemistry: algebraic methods. [Workshop, August 9-11, 1978] (open access)

Numerical algorithms in chemistry: algebraic methods. [Workshop, August 9-11, 1978]

The National Resource for Computation in Chemistry was established to make information on existing and developing computational methodologies available to all segments of the chemistry community, to make state-of-the-art computation facilities accessible to the chemistry community, and to foster research and development of new computational methods for application to chemical problems. Attention was directed to algebraic methods because of their continuing importance in chemical applications. This volume contains digests of the contributions to the workshop of August 9--11, 1978. Presentations were given on eigenvalue problems, linear systems of equations, and integral transformations. One of the papers in this volume was abstracted and indexed separately. (RWR)
Date: August 9, 1978
Creator: Moler, C. & Shavitt, I. (eds.)
Object Type: Article
System: The UNT Digital Library
Droplet phase characteristics in liquid-dominated steam--water nozzle flow (open access)

Droplet phase characteristics in liquid-dominated steam--water nozzle flow

An experimental study was undertaken to determine the droplet size distribution, the droplet spatial distribution and the mean droplet velocity in low-quality, steam-water flow from a rectangular cross-section, converging-diverging nozzle. A unique forward light scattering technique was developed for droplet size distribution measurements. Droplet spatial variations were investigated using light transmission measurements, and droplet velocities were measured with a laser-Doppler velocimeter (LDV) system incorporating a confocal Fabry-Perot interferometer. Nozzle throat radius of curvature and height were varied to investigte their effects on droplet size. Droplet size distribution measurements yielded a nominal Sauter mean droplet diameter of 1.7 ..mu..m and a nominal mass-mean droplet diameter of 2.4 ..mu..m. Neither the throat radius of curvature nor the throat height were found to have a significant effect upon the nozzle exit droplet size. The light transmission and LDV measurement results confirmed both the droplet size measurements and demonstrated high spatial uniformity of the droplet phase within the nozzle jet flow. One-dimensional numerical calculations indicated that both the dynamic breakup (thermal equilibrium based on a critical Weber number of 6.0) and the boiling breakup (thermal nonequilibrium based on average droplet temperature) models predicted droplet diameters on the order of 7.5 ..mu..m, which are approximately …
Date: August 9, 1978
Creator: Alger, T.W.
Object Type: Report
System: The UNT Digital Library