Modeling results for a linear simulator of a divertor (open access)

Modeling results for a linear simulator of a divertor

A divertor simulator, IDEAL, has been proposed by S. Cohen to study the difficult power-handling requirements of the tokamak program in general and the ITER program in particular. Projections of the power density in the ITER divertor reach {approximately} 1 Gw/m{sup 2} along the magnetic fieldlines and > 10 MW/m{sup 2} on a surface inclined at a shallow angle to the fieldlines. These power densities are substantially greater than can be handled reliably on the surface, so new techniques are required to reduce the power density to a reasonable level. Although the divertor physics must be demonstrated in tokamaks, a linear device could contribute to the development because of its flexibility, the easy access to the plasma and to tested components, and long pulse operation (essentially cw). However, a decision to build a simulator requires not just the recognition of its programmatic value, but also confidence that it can meet the required parameters at an affordable cost. Accordingly, as reported here, it was decided to examine the physics of the proposed device, including kinetic effects resulting from the intense heating required to reach the plasma parameters, and to conduct an independent cost estimate. The detailed role of the simulator in …
Date: June 23, 1993
Creator: Hooper, E. B.; Brown, M. D.; Byers, J. A.; Casper, T. A.; Cohen, B. I.; Cohen, R. H. et al.
Object Type: Report
System: The UNT Digital Library
Quantum harmonic Brownian motion in a general environment: A modified phase-space approach (open access)

Quantum harmonic Brownian motion in a general environment: A modified phase-space approach

After extensive investigations over three decades, the linear-coupling model and its equivalents have become the standard microscopic models for quantum harmonic Brownian motion, in which a harmonically bound Brownian particle is coupled to a quantum dissipative heat bath of general type modeled by infinitely many harmonic oscillators. The dynamics of these models have been studied by many authors using the quantum Langevin equation, the path-integral approach, quasi-probability distribution functions (e.g., the Wigner function), etc. However, the quantum Langevin equation is only applicable to some special problems, while other approaches all involve complicated calculations due to the inevitable reduction (i.e., contraction) operation for ignoring/eliminating the degrees of freedom of the heat bath. In this dissertation, the author proposes an improved methodology via a modified phase-space approach which employs the characteristic function (the symplectic Fourier transform of the Wigner function) as the representative of the density operator. This representative is claimed to be the most natural one for performing the reduction, not only because of its simplicity but also because of its manifestation of geometric meaning. Accordingly, it is particularly convenient for studying the time evolution of the Brownian particle with an arbitrary initial state. The power of this characteristic function is …
Date: June 23, 1993
Creator: Yeh, L.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
[Recent results and near term expectations in tokamak research in the US, Europe and Japan] (open access)

[Recent results and near term expectations in tokamak research in the US, Europe and Japan]

This report discusses the scientific and economic feasibility of fusion energy, especially in regards to the tokamak reactor.
Date: June 23, 1993
Creator: Meade, D.
Object Type: Article
System: The UNT Digital Library
Texas Attorney General Opinion: DM-230 (open access)

Texas Attorney General Opinion: DM-230

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Dan Morales, regarding a legal question submitted for clarification; Whether article 45.54 of the Code of Criminal Procedure permits a justice of the peace to dismiss a complaint against a defendant who has failed to successfully complete a driving safety course (RQ-512)
Date: June 23, 1993
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: LO93-055 (open access)

Texas Attorney General Opinion: LO93-055

Letter opinion issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Dan Morales, regarding a legal question submitted for clarification; Whether the Greater San Marcos Chamber of Commerce, the Greater San Marcos Economic Development Council, and the San Marcos Convention and Visitors Bureau are governmental bodies subject to the Texas Open Meetings Act, V.T.C.S. article 6252-17 (RQ-472)
Date: June 23, 1993
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Ethanol and Clean Air: The "Reg-Neg" Controversy and Subsequent Events (open access)

Ethanol and Clean Air: The "Reg-Neg" Controversy and Subsequent Events

The Clean Air Act Amendments (CAAA), enacted in 1990, called for cleaner automotive fuels in order to upgrade air quality. This appeared to provide new market potential for ethanol, which is obtained from corn grown in the midwestern United States, and which is already in large-scale use in a blend of ten percent ethanol to ninety percent gasoline. The CAAA left specific details of the clean fuels program to be worked out by the Environmental Protection Agency (EPA), in consultation with the interested parties.
Date: June 22, 1993
Creator: Segal, Migdon
Object Type: Report
System: The UNT Digital Library
High- and low-temperature bonding techniques for microstructures (open access)

High- and low-temperature bonding techniques for microstructures

The ability to bond together two or more silicon wafers greatly expands the variety and complexity of silicon microstructures that can be designed and fabricated. At LLNL, microstructures have been used for many years as hardware in scientific experiments. The activity has recently been expanded into other areas to include microinstruments for biomedical applications and for chemical analysis. Both high temperature (1100{degrees}C) bonding techniques have been used, depending on the application. This paper discusses these applications with emphasis on the most extensive which is the fabrication of microchannel coolers for diode arrays.
Date: June 22, 1993
Creator: Ciarlo, D. R.
Object Type: Article
System: The UNT Digital Library
Natural gas monthly, June 1993 (open access)

Natural gas monthly, June 1993

The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information.
Date: June 22, 1993
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Texas Attorney General Opinion: LO93-054 (open access)

Texas Attorney General Opinion: LO93-054

Letter opinion issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Dan Morales, regarding a legal question submitted for clarification;Whether a sheriff may also serve as volunteer fireman(ID# 20119).
Date: June 22, 1993
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Register, Volume 18, Number 48, Pages 4117-4150, June 22, 1993 (open access)

Texas Register, Volume 18, Number 48, Pages 4117-4150, June 22, 1993

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: June 22, 1993
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Analysis of explosion-induced releases of toxic materials at an environmental restoration project (open access)

Analysis of explosion-induced releases of toxic materials at an environmental restoration project

Prior to 1988, a variety of materials were buried on the US DOE Oak Ridge Reservation. Records of the disposal operations are incomplete and toxic materials may have been placed adjacent to potential explosives. One of the safety concerns in conducting an environmental restoration project at the burial sites, is the possibility of an explosion which could release toxic materials to the atmosphere. A safety analysis examined the consequences of such releases by first postulating an upper bound for the strength of an explosive. A correlation, developed by Steindler and Seefeldt of Argonne National Laboratory, was then used to estimate the amount and particle-size distribution of the material that could become airborne from the explosion. The estimated amount of airborne material was the source term in an atmospheric dispersion model which was used to calculate infinite-time, concentration-time integrals and 5-minute, time- weighted average concentrations at locations down-wind from the explosion. The dispersion model includes particle deposition as a function of particle-size distribution class. The concentration-time integrals and average concentrations were compared to published guidelines to assess the consequences of an accidental explosion.
Date: June 21, 1993
Creator: Bloom, S. G. & Moon, W. H. Jr.
Object Type: Article
System: The UNT Digital Library
Pulsed laser kinetic studies of liquids under high pressure (open access)

Pulsed laser kinetic studies of liquids under high pressure

Experiments have been developed for measuring the rates of chemical reactions liquids and in supercritical Co[sub 2]. A pulsed (Q-switch) Nd:YAG laser at 355 nm was the pump beam for laser flash photolysis studies of molybdenum and tungsten hexacarbonyls undergoing ligand displacement reactions by bidentate chelating agents such as 2,2[prime]-bipyridine in toluene. Experiments were carried out at 0.1 to 150 MPa. In the case of molybdenum complexes, the reaction mechanism for thermal ring closure is found from activation volumes to change from associative interchange to dissociative interchange as substituents on the 2,2[prime]-bipyridine ligands become bulkier. In a similar study of more rigid, substituted phenanthroline bidentate ligands it was found that substituent bulkiness had little effect on the thermal ring closure mechanism. Similar high pressure flash photolysis experiments with tungsten hexacarbonyl have also been completed. The concentration dependence of the fluorescence and nonradiative decay quantum yields for cresyl violet in several solvent have been reported as well as stability constants for the complexation of lithium ion by four different crown ethers dissolved in a room temperature molten salt.
Date: June 21, 1993
Creator: Eyring, E. M.
Object Type: Report
System: The UNT Digital Library
Pulsed laser kinetic studies of liquids under high pressure. Final technical report, April 1, 1990--March 31, 1993 (open access)

Pulsed laser kinetic studies of liquids under high pressure. Final technical report, April 1, 1990--March 31, 1993

Experiments have been developed for measuring the rates of chemical reactions liquids and in supercritical Co{sub 2}. A pulsed (Q-switch) Nd:YAG laser at 355 nm was the pump beam for laser flash photolysis studies of molybdenum and tungsten hexacarbonyls undergoing ligand displacement reactions by bidentate chelating agents such as 2,2{prime}-bipyridine in toluene. Experiments were carried out at 0.1 to 150 MPa. In the case of molybdenum complexes, the reaction mechanism for thermal ring closure is found from activation volumes to change from associative interchange to dissociative interchange as substituents on the 2,2{prime}-bipyridine ligands become bulkier. In a similar study of more rigid, substituted phenanthroline bidentate ligands it was found that substituent bulkiness had little effect on the thermal ring closure mechanism. Similar high pressure flash photolysis experiments with tungsten hexacarbonyl have also been completed. The concentration dependence of the fluorescence and nonradiative decay quantum yields for cresyl violet in several solvent have been reported as well as stability constants for the complexation of lithium ion by four different crown ethers dissolved in a room temperature molten salt.
Date: June 21, 1993
Creator: Eyring, E. M.
Object Type: Report
System: The UNT Digital Library
Recirculating induction accelerators for heavy ion fusion (open access)

Recirculating induction accelerators for heavy ion fusion

We have recently completed a two-year study of recirculating induction heavy-ion accelerators (recirculators) as low-cost drivers for inertial-fusion-energy power plants. We present here a summary of that study and other recent work on recirculators.
Date: June 21, 1993
Creator: Barnard, J. J.; Deadrick, F. & Bangerter, R. O.
Object Type: Article
System: The UNT Digital Library
Slurry combustion. Volume 1, Text: Final report (open access)

Slurry combustion. Volume 1, Text: Final report

The project described in this Report was to investigate the possibility of using sorbent added to coal-water fuel (CWF) mixtures as a means of reducing SOX emissions when burning Ohio coal. The results are significantly encouraging, with SOX concentrations reduced by amounts ranging from 25% to 65%, depending on the sorbent type and the firing conditions, where one major condition identified was the residence time in the flame gases. With the sorbent-loaded slurrys, the trend generally showed increasing SO{sub 2} capture with increasing sorbent loading. There were significant differences between the two different mixture formulations, however: The calcite/No. 8-seam mixture showed significantly higher SO{sub 2} capture at all times (ranging from 45% to 65%) than did the dolomite/No. 5 seam mixture (ranging from 25% to 45%). If the successes so far achieved are not to be wasted, advantage should be taken of these encouraging results by extending the work at both the present scale to determine the other unknown factors controlling sorption efficiency, and at larger scale to start implementation in commercial systems.
Date: June 21, 1993
Creator: Essenhigh, R.
Object Type: Report
System: The UNT Digital Library
Texas Attorney General Opinion: LO93-053 (open access)

Texas Attorney General Opinion: LO93-053

Letter opinion issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Dan Morales, regarding a legal question submitted for clarification;Clarification and reconsideration of Attorney General Opinion DM-210(1993)(ID# 19950)
Date: June 21, 1993
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Characterization and evaluation of Y{sub 2}O{sub 3}-stabilized cubic ZrO{sub 2} for single crystal fibers. Final report (open access)

Characterization and evaluation of Y{sub 2}O{sub 3}-stabilized cubic ZrO{sub 2} for single crystal fibers. Final report

The goal of this research was to develop the understanding of the structure/property relations in Y{sub 2}O{sub 3}-stabilized cubic ZrO{sub 2} (Y-CSZ) single crystals with emphasis on the potential use of these materials as a fibrous reinforcement for high temperature structural applications. In particular, the issues addressed include: (i) determination of the structure of as-grown Y-CSZ and its relation to the deformation behavior and (ii) initial fiber growth and evaluation. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.
Date: June 20, 1993
Creator: Heuer, A. H.
Object Type: Report
System: The UNT Digital Library
Structure and behavior of triad interactions for a Boussinesq system arising in a model for the formation sand ridges (open access)

Structure and behavior of triad interactions for a Boussinesq system arising in a model for the formation sand ridges

The Boussinesq system describes weakly nonlinear dispersive long waves plasmas and incompressible irrotational fluids. This study presents some results regarding the structure and behavior of a system of equations that yield the spatial structure of triad interactions in the Boussinesq system. Such a system forms part of a model for the formation and evolution of sand ridges on the continental shelf. The aims of this study are to provide some insight into the behavior of the triad system and into the sand ridge model in particular.
Date: June 20, 1993
Creator: Restrepo, J.M. & Bona, J.L.
Object Type: Report
System: The UNT Digital Library
Summary of All Reported Accidents in Rural Areas of Texas for May 1993 (open access)

Summary of All Reported Accidents in Rural Areas of Texas for May 1993

Monthly report providing tabular statistical information about motor vehicle accidents in rural areas of Texas during 1993, with data broken out by various criteria including number of persons, locations, types of accidents, time of day, and other factors.
Date: June 20, 1993
Creator: Texas. Department of Public Safety. Statistical Services.
Object Type: Report
System: The Portal to Texas History
Summary of All Reported Accidents in the State of Texas for May 1993 (open access)

Summary of All Reported Accidents in the State of Texas for May 1993

Monthly report providing tabular statistical information about motor vehicle accidents in Texas during 1993, with data broken out by various criteria including number of persons, locations, types of accidents, time of day, and other factors.
Date: June 20, 1993
Creator: Texas. Department of Public Safety. Statistical Services.
Object Type: Report
System: The Portal to Texas History
Modeling the response of ecosystems to CO{sub 2} and climate change. Progress report, September 1, 1992--June 19, 1993 (open access)

Modeling the response of ecosystems to CO{sub 2} and climate change. Progress report, September 1, 1992--June 19, 1993

In recognition of the role of plants in the bio-geosphere carbon cycle, the Department of Energy (OHER) initiated a research program: The Direct Effects of Increasing Carbon Dioxide on Vegetation. This report describes the continuing research that we are conducting as part of this program. The ultimate goal of our research is to develop computer models capable of predicting responses of plants and ecosystems to the direct and indirect effects of atmospheric levels of carbon dioxide that are approximately twice those of the preindustrial period. The understanding of ecosystem responses to elevated CO{sub 2} necessarily depends on knowledge of responses of individual plants and their interactions with one another and their environment Our research approach incorporates the study and modeling of response to CO{sub 2} at all levels of the plant-community-ecosystem hierarchy, in an effort to understand the linkages and translation of effects of CO{sub 2} from one level to another. The research results reported here focus at several different levels of this hierarchy, and are highlights of accomplishments for the period September 1992 to June 1993.
Date: June 19, 1993
Creator: Reynolds, J. F.; Kemp, P. R. & Chen, J.
Object Type: Report
System: The UNT Digital Library
The three-point function as a probe of models for large-scale structure (open access)

The three-point function as a probe of models for large-scale structure

The authors analyze the consequences of models of structure formation for higher-order (n-point) galaxy correlation functions in the mildly non-linear regime. Several variations of the standard [Omega] = 1 cold dark matter model with scale-invariant primordial perturbations have recently been introduced to obtain more power on large scales, R[sub p] [approximately]20 h[sup [minus]1] Mpc, e.g., low-matter-density (non-zero cosmological constant) models, [open quote]tilted[close quote] primordial spectra, and scenarios with a mixture of cold and hot dark matter. They also include models with an effective scale-dependent bias, such as the cooperative galaxy formation scenario of Bower, et al. The authors show that higher-order (n-point) galaxy correlation functions can provide a useful test of such models and can discriminate between models with true large-scale power in the density field and those where the galaxy power arises from scale-dependent bias: a bias with rapid scale-dependence leads to a dramatic decrease of the hierarchical amplitudes Q[sub J] at large scales, r [approx gt] R[sub p]. Current observational constraints on the three-point amplitudes Q[sub 3] and S[sub 3] can place limits on the bias parameter(s) and appear to disfavor, but not yet rule out, the hypothesis that scale-dependent bias is responsible for the extra power observed …
Date: June 19, 1993
Creator: Frieman, J.A. (Fermi National Accelerator Lab., Batavia, IL (United States)) & Gaztanaga, E. (Univ. of Oxford (United Kingdom))
Object Type: Report
System: The UNT Digital Library
The three-point function as a probe of models for large-scale structure (open access)

The three-point function as a probe of models for large-scale structure

The authors analyze the consequences of models of structure formation for higher-order (n-point) galaxy correlation functions in the mildly non-linear regime. Several variations of the standard {Omega} = 1 cold dark matter model with scale-invariant primordial perturbations have recently been introduced to obtain more power on large scales, R{sub p} {approximately}20 h{sup {minus}1} Mpc, e.g., low-matter-density (non-zero cosmological constant) models, {open_quote}tilted{close_quote} primordial spectra, and scenarios with a mixture of cold and hot dark matter. They also include models with an effective scale-dependent bias, such as the cooperative galaxy formation scenario of Bower, et al. The authors show that higher-order (n-point) galaxy correlation functions can provide a useful test of such models and can discriminate between models with true large-scale power in the density field and those where the galaxy power arises from scale-dependent bias: a bias with rapid scale-dependence leads to a dramatic decrease of the hierarchical amplitudes Q{sub J} at large scales, r {approx_gt} R{sub p}. Current observational constraints on the three-point amplitudes Q{sub 3} and S{sub 3} can place limits on the bias parameter(s) and appear to disfavor, but not yet rule out, the hypothesis that scale-dependent bias is responsible for the extra power observed on large scales.
Date: June 19, 1993
Creator: Frieman, J. A. & Gaztanaga, E.
Object Type: Report
System: The UNT Digital Library
Automated assistance for detecting malicious code (open access)

Automated assistance for detecting malicious code

This paper gives an update on the continuing work on the Malicious Code Testbed (MCT). The MCT is a semi-automated tool, operating in a simulated, cleanroom environment, that is capable of detecting many types of malicious code, such as viruses, Trojan horses, and time/logic bombs. The MCT allows security analysts to check a program before installation, thereby avoiding any damage a malicious program might inflict.
Date: June 18, 1993
Creator: Crawford, R.; Kerchen, P.; Levitt, K.; Olsson, R.; Archer, M. & Casillas, M.
Object Type: Report
System: The UNT Digital Library