States

An Efficient Microwave Power Source: Free-electron Laser Afterburner (open access)

An Efficient Microwave Power Source: Free-electron Laser Afterburner

A kind of microwave power source, called a free-electron laser afterburner (FEL afterburner) which consists of a free-electron laser buncher and a slow-wave output structure sharing a magnetic wiggler field with the buncher, is proposed. The buncher and the slow-wave structure can operate in either a travelling-wave state or a standing-wave state. In the buncher, the wiggler field together with the radiation field makes an electron beam bunched, and in the slow-wave structure the wiggler field keeps the beam bunched while the bunched beam interacts strongly with the slow-wave structure and so produces rf power. The bunching process comes from the free-electron laser mechanism and the generating process of rf power is in a slow-wave structure. A three-dimensional, time-dependent code is used to simulate a particular standing-wave FEL afterburner and it is shown that rf power of up to 1.57 GW can be obtained, at 17.12 GHz, from a l-kA, 5-MeV electron beam.
Date: March 4, 1993
Creator: Wang, C. & Sessler, Andrew M.
Object Type: Article
System: The UNT Digital Library
Errors when shock waves interact due to numerical shock width (open access)

Errors when shock waves interact due to numerical shock width

A simple test problem proposed by Noh, a strong shock reflecting from a rigid wall, demonstrates a generic problem with numerical shock capturing algorithms at boundaries that Noh called excess wall heating.'' We show that the same type of numerical error occurs in general when shock waves interact. The underlying cause is the non-uniform convergence to the hyperbolic solution of the inviscid limit of the solution to the PDEs with viscosity. The error can be understood from an analysis of the asymptotic solution. For a propagating shock, there is a difference in the total energy of the parabolic wave relative to the hyperbolic shock. Moreover, the relative energy depends on the strength of the shock. The error when shock waves interact is due to the difference in the relative energies between the incoming and outgoing shock waves. It is analogous to a phase shift in a scattering matrix. A conservative differencing scheme correctly describes the Hugoniot jump conditions for a steady propagating shock. Therefore, the error from the asymptotics occurs in the transient when the waves interact. The entropy error that occurs in the interaction region remains localized but does not dissipate. A scaling argument shows that as the viscosity …
Date: March 4, 1993
Creator: Menikoff, R.
Object Type: Article
System: The UNT Digital Library
Development of advanced NO[sub x] control concepts for coal-fired utility boilers (open access)

Development of advanced NO[sub x] control concepts for coal-fired utility boilers

The complete CombiNO[sub x], process has now been demonstrated at a level that is believed to be representative of a full-scale boiler in terms of mixing capabilities. A summary of the results is displayedin Figure 5-1. While firing Illinois Coal on the Reburn Tower, Advanced Reburning was capable of reducing NO[sub x], by 83 percent. The injection of methanol oxidized 50--58 percent of the existing NO to N0[sub 2]. Assuming that 85 percent of the newly formed N0[sub 2] can be scrubbed in a liquor modified wet-limestone scrubber, the CombiNO[sub x], process has been shown capable of reducing NO[sub 2], by 90--91 percent in a large pilot-scale coal-fired furnace. There is still uncertainty regarding the fate of the N0[sub 2] formed with methanol injection. Tests should be conducted to determine whether the reconversion is thermodynamic or catalytic, and what steps can be taken (such as quench rate) to prevent it from happening.
Date: March 4, 1993
Creator: Evans, A.; Pont, J. N.; England, G. & Seeker, W. R.
Object Type: Report
System: The UNT Digital Library
Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane (open access)

Development of vanadium-phosphate catalysts for methanol production by selective oxidation of methane

Amax R D will perform laboratory scale development of a promising, practical catalyst for the selective oxidation of methane to methanol. The primary component of this catalyst is vanadium-phosphate (VPO) which has shown good activity and selectivity in the partial oxidation of n-butane and propane but has not been studied in detail for methane oxidation. The goal of the project is to develop a catalyst which allows methane oxidation to methanol to be conducted at high conversion and selectivity. A low CH[sub 4]/O[sub 2] ratio will be employed with air as the source of oxygen. Temperatures below 600[degrees]C and pressures up to 20 atm are to be investigated. The use of steam in the feed gas will also be investigated. The catalyst development strategy will be to utilize promoters and supports to improve the activity and selectivity of the unmodified VPO catalyst. The catalyst testing reactor system was used to perform blank (empty) reactor runs over a wide range of temperatures, pressure, and flow rates. No methane conversion was observed at temperatures of 500[degrees]C or lower in any of the tests. At higher temperatures, significant methane conversion to carbon dioxide was observed. At 550[degrees]C, 300 psig, and the highest flow …
Date: March 4, 1993
Creator: McCormick, Robert L. & Jha, Mahesh C.
Object Type: Report
System: The UNT Digital Library
Methyl chloride via oxyhydrochlorination of methane (open access)

Methyl chloride via oxyhydrochlorination of methane

Work to develop a highly selective methyl chloride synthesis catalyst continued, but no stable catalyst with >80% selectivity at 20% methane exists yet. Effort was made on finalizing the pre- engineering scope definition of the Process Demonstration Unit. Natural gas purification, reactor, reactor effluent and MeCl purification, and anhydrous HCl recovery are discussed.
Date: March 4, 1993
Creator: Naasz, B.
Object Type: Report
System: The UNT Digital Library
Method of calculation of heat generation rates for DWPF glass (open access)

Method of calculation of heat generation rates for DWPF glass

The Waste Acceptance Preliminary Specifications (WAPS) require estimates of the heat generation rate of DWPF waste glasses. Estimates of the heat generation rates of projected glass compositions are to be reported in the Waste Form Qualification Report. Similar estimates for actual production glasses are to be reported in the Production Records. In this report, a method of calculating the heat generation rate from the radionuclide inventory is provided. Application of the method to the DWPF Design-Basis glass indicates that the heat generation rate can be accurately estimated from the Sr-90, Y-90, Cs-137, Ba-137m, and Pu-238 contents alone.
Date: February 4, 1993
Creator: Plodinec, M.J.
Object Type: Report
System: The UNT Digital Library
Texas Register, Volume 18, Number 34, Pages 2883-2913, May 4, 1993 (open access)

Texas Register, Volume 18, Number 34, Pages 2883-2913, May 4, 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: May 4, 1993
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Texas Register, Volume 18, Number 43, Pages 3533-3587, June 4, 1993 (open access)

Texas Register, Volume 18, Number 43, Pages 3533-3587, June 4, 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 4, 1993
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
The origins of ordering in CuPt (open access)

The origins of ordering in CuPt

The alloy CuPt is one of the few that order into a L1{sub 1} crystal structure, i.e. planes of copper and planes of planes of planes of platinum perpendicular to the < 111 > direction. For disordered CuPt, the calculated Warren-Cowley short-range order parameter indicates an instability to concentration fluctuations with a wave-vector of ({1/2}, {1/2}, {1/2}), consistent with L1{sub 1} ordering. We show that this rare tendency is due to this ordering vector arising from the large joint density of states associated with L point and X point van-Hove singularities which lie near the Fermi energy.
Date: August 4, 1993
Creator: Clark, J. F.; Pinski, F. J.; Sterne, P. A.; Johnson, D. D.; Staunton, J. B. & Ginatempo, B.
Object Type: Article
System: The UNT Digital Library
Sitewide Environmental Assessment for the National Renewable Energy Laboratory, Golden, Colorado (open access)

Sitewide Environmental Assessment for the National Renewable Energy Laboratory, Golden, Colorado

The Solar Energy Research, Development, and Demonstration Act of 1974 authorized a federal program to develop solar energy as a viable source of the nation`s future energy needs. Under this authority, the National Renewable Energy Laboratory (NREL) was created as a laboratory of the Department of Energy (DOE) to research a number of renewable energy possibilities. The laboratory conducts its operations both in government-owned facilities on the NREL South Table Mountain (STM) Site near Golden, Colorado, and in a number of leased facilities, particularly the Denver West Office Park. NREL operations include research in energy technologies, and other areas of national environmental and energy technology interest. Examples of these technologies include electricity from sunlight with solar cells (photovoltaics); energy from wind (windmills or wind turbines); conversion of plants and plant products (biomass) into liquid fuels (ethanol and methanol); heat from the sun (solar thermal) in place of wood, oil, gas, coal and other forms of heating; and solar buildings. NREL proposes to continue and expand the present R&D efforts in C&R energy by making infrastructure improvements and constructing facilities to eventually consolidate the R&D and associated support activities at its STM Site. In addition, it is proposed that operations continue …
Date: May 4, 1993
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Initial weights and dimensions of corrosion coupons installed in IDMS in August 1993 (open access)

Initial weights and dimensions of corrosion coupons installed in IDMS in August 1993

New corrosion coupons were installed in the Feed Preparation System and the Melter/Off-Gas System of Integrated DWPF Melter System (IDMS) in August 1993. The new coupons are replacements for similar coupons which were in the IDMS since 1989 but were removed for metallurgical evaluation in April 1993. original coupons still remain on the corrosion racks in the Melter and the Off-Gas Stack. Baseline data for the replacement coupons are described in this report.
Date: October 4, 1993
Creator: Imrick, K.
Object Type: Report
System: The UNT Digital Library
Chromosome 19 International Workshop. Final report, January 1, 1992--December 31, 1992 (open access)

Chromosome 19 International Workshop. Final report, January 1, 1992--December 31, 1992

The Second International Workshop on Human Chromosome 19 was hosted on January 25 and 26, 1992, by the Department of Human Genetics, University Hospital Nijmegen, The Netherlands, at the `Meerdal Conference Center`. The workshop was supported by a grant from the European Community obtained through HUGO, the Dutch Research Organization (NWO) and the Muscular Dystrophy Association (MDA). Travel support for American participants was provided by the Department of Energy. The goals of this workshop were to produce genetic, physical and integrated maps of chromosome 19, to identify inconsistencies and gaps, and to discuss and exchange resources and techniques available for the completion of these maps. The second day of the meeting was largely devoted to region or disease specific efforts. In particular, the meeting served as a platform for assessing and discussing the recent progress made into the molecular elucidation of myotonic dystrophy.
Date: January 4, 1993
Creator: Pericak-Vance, M. A.; Ropers, H. H. & Carrano, A. J.
Object Type: Report
System: The UNT Digital Library
Fundamental studies of coal liquefaction. Quarterly report No. 5, October 1, 1992--January 1, 1993 (open access)

Fundamental studies of coal liquefaction. Quarterly report No. 5, October 1, 1992--January 1, 1993

The results for the control run for a single particle are shown in Figure 1. The figure, which includes other thermolytic data for Illinois No. 6 coal, shows that the particle was stable in size to around 440{degree}C. At that point it contracted very rapidly to about half its size over the next 15{degrees}. Also shown are data for the same coal from SRI`s field ionization mass spectrometer (FIMS), in which case a sample of the coal is heated at 2.5{degrees}C/min from ambient to 500{degrees}C and the effluent is swept into mass spectrometer. The evolution of the coal volatiles is reflected by accumulated ion count with increasing temperature, and is presented in the figure as the fraction of total volatiles. As the figure shows, the abrupt increase in volatility corresponds very closely to the equally abrupt reduction in particle size. The weight average molecular weight profile from the FIMS work is also in the figure, and shows that the coal experiences a simple loss of volatiles of increasing molecular weight up to around 440{degrees}C. At that point pyrolysis and fragmentation come about, reflected in the quick reversal and decline in molecular weight. The high rate of volatility and shrinkage are …
Date: February 4, 1993
Creator: Ross, D. S.
Object Type: Report
System: The UNT Digital Library
Development of advanced NO{sub x} control concepts for coal-fired utility boilers. Quarterly technical progress report No. 8, July 1, 1992--September 30, 1992 (open access)

Development of advanced NO{sub x} control concepts for coal-fired utility boilers. Quarterly technical progress report No. 8, July 1, 1992--September 30, 1992

The complete CombiNO{sub x}, process has now been demonstrated at a level that is believed to be representative of a full-scale boiler in terms of mixing capabilities. A summary of the results is displayed in Figure 5-1. While firing Illinois Coal on the Reburn Tower, Advanced Reburning was capable of reducing NO{sub x}, by 83 percent. The injection of methanol oxidized 50--58 percent of the existing NO to N0{sub 2}. Assuming that 85 percent of the newly formed N0{sub 2} can be scrubbed in a liquor modified wet-limestone scrubber, the CombiNO{sub x}, process has been shown capable of reducing NO{sub 2}, by 90--91 percent in a large pilot-scale coal-fired furnace. There is still uncertainty regarding the fate of the N0{sub 2} formed with methanol injection. Tests should be conducted to determine whether the reconversion is thermodynamic or catalytic, and what steps can be taken (such as quench rate) to prevent it from happening.
Date: March 4, 1993
Creator: Evans, A.; Pont, J. N.; England, G. & Seeker, W. R.
Object Type: Report
System: The UNT Digital Library
Fundamental studies of coal liquefaction. Quarterly report No. 6, January 1--April 1, 1993 (open access)

Fundamental studies of coal liquefaction. Quarterly report No. 6, January 1--April 1, 1993

Figures 3, 4, and 5 display images of two adjacent particles chosen for analysis with characteristic dimensions of 50--100 {mu}m Figure 3 shows that there is essentially no change up to 395{degrees}C over an 18 min period, but at that point the particle labeled a begins to shrink. The action continues in Figure 4 where the particle contracts to about half its initial size over a 45 sec period as the temperature, increases from 424{degrees}C to 430{degrees}C, at which point the contraction stops. The size profile for a is presented in Figure 6 and compares very well with the profile generated in an earlier experiment from our last report. As just noted, this agreement suggests that this behavior is representative of at least one class of particle in the sample. Figure 5 shows that there is a second, higher temperature range of activity, represented by the changes in particle b. This particle contracts to about half its size from 450{degrees} to 460{degrees}C over 1 min. The temperature was held at 460{degrees} and there appears to be an additional 7--10% contraction over 10 min at that temperature, although the scatter seen in Figure 6 shows that change is not outside our …
Date: May 4, 1993
Creator: Ross, D. S.
Object Type: Report
System: The UNT Digital Library
Status of an induction accelerator driven, high-power microwave generator at Livermore (open access)

Status of an induction accelerator driven, high-power microwave generator at Livermore

The authors are testing an enhanced version of the Choppertron, a high-power rf generator which shows great promise of achieving greater than 400 MW of output power at 11.4 GHz with stable phase and amplitude. This version of the Choppertron is driven by a 5-MeV, 1-kA induction accelerator beam. Modifications to the original Choppertron included aggressive suppression of high order modes in the two output structures, lengthening of the modulation section to match for higher beam energy, and improved efficiency. Final results of the original Choppertron experiment, status of the ongoing experiment and planned experiments for the next year are presented. The motivation of the research program at the LLNL Microwave Source Facility is to develop microwave sources which could be suitable drivers for a future TeV linear e{sup +}e{sup {minus}} collider.
Date: February 4, 1993
Creator: Houck, T. L. & Westenskow, G. A.
Object Type: Article
System: The UNT Digital Library
The liquid helium thermosyphon for the GEM detector magnet (open access)

The liquid helium thermosyphon for the GEM detector magnet

The GEM detector magnet, a horizontal solenoid 19.5 m in diameter and wound with a niobium-titanium cable in conduit, will be located with it`s axis 19.5 m below grade. The conductor is wound on the inside of an aluminum bobbin which is cooled by liquid helium which flows by natural convection in a thermosyphon loop from a large storage dewar located at the ground surface. The function of the thermosyphon system is to absorb the environmental heat load as well as any internally generated heat. In the first category is included that heat which is transfered to the magnet by way of the mechanical supports, the insulation and the current leads. The internally generated heat includes the resistive heating within the normally conducting conductor splices and the inductive heating of the bobbin during current transients. Though similar systems have been employed elsewhere, there are some unique aspects to the present design. By taking advantage of the large vertical head available, the parallel heat exchanger passes within the magnet remain sub-cooled, thus insuring single phase coolant within the magnet. It is believed that this will be the first instance of such a large vertical head being used to this advantage in …
Date: May 4, 1993
Creator: Warren, R. P.
Object Type: Article
System: The UNT Digital Library
Texas Attorney General Opinion: LO93-001 (open access)

Texas Attorney General Opinion: LO93-001

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 port commissioner’s ownership of a company that hires the services of pilots as an agent for ships calling at the port disqualifies him from service on the pilot board (RQ-380)
Date: January 4, 1993
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
The urban perspectives of acid rain. Workshop summary (open access)

The urban perspectives of acid rain. Workshop summary

This report documents discussions held during a workshop an Urban Perspective of Acid Rain. The workshop was sponsored by the Office of the Director, National Acid Precipitation Assessment Program (NAPAP). NAPAP anticipates giving increased emphasis to the benefits in urban areas of emissions reductions. The goal of this informal, exploratory workshop was to serve as a first step towards identifying pollutant monitoring, and research and assessment needs to help answer, from an urban perspective, the two key questions posed to NAPAP by Congress: (1) what are the costs, benefits, and effectiveness of the acid rain control program, and (2) what reductions in deposition, rates are needed in order to prevent adverse effects? The workshop addressed research activities needed to respond to these questions. The discussions focused. sequentially, on data needs, data and model availability, and data and modeling gaps. The discussions concentrated on four areas of effects: human health, materials, urban forests, and visibility.
Date: June 4, 1993
Creator: Tonn, B. E.
Object Type: Article
System: The UNT Digital Library
Digital conversion of INEL archeological data using ARC/INFO and Oracle (open access)

Digital conversion of INEL archeological data using ARC/INFO and Oracle

This report documents the procedures used to convert archaeological data for the INEL to digital format, lists the equipment used, and explains the verification and validation steps taken to check data entry. It also details the production of an engineered interface between ARC/INFO and Oracle.
Date: November 4, 1993
Creator: Lee, R. D.; Brizzee, J. & White, L.
Object Type: Report
System: The UNT Digital Library
Electronic cone penetration testing at the Hanford Site, 200 West Area (open access)

Electronic cone penetration testing at the Hanford Site, 200 West Area

The 200 West Area Carbon Tetrachloride Expedited Response Action (ERA) is being conducted by the US Department of Energy (DOE) at the direction of the US Environmental Protection Agency (EPA) and the Washington Department of Ecology as a provision of both the Comprehensive Environmental Response Compensation and Liability Act of 1980 (CERCLA) and the Integrated Demonstration for Cleanup of Volatile Organic Compounds at Arid Sites (VOC-Arid ID). The ERA allows expedited response to be taken at waste sites where damage to the environment can be significantly reduced by early action to locate, identify the extent, and remediate imminent hazards. The ERA is focusing specifically on the removal of carbon tetrachloride vapor from the soil column and protection of the groundwater in the 200 West Area. The VOC-Arid ID program allows demonstration of new drilling technologies for environmental characterization monitoring and remediation. Soil vapor vacuum extraction has been proposed to remediate the site. This may require vapor extraction wells to be installed within the plume.
Date: June 4, 1993
Creator: Rohay, V. J.
Object Type: Report
System: The UNT Digital Library
HEGRS: Mechanical design of a high-energy, gamma-ray spectrometer (open access)

HEGRS: Mechanical design of a high-energy, gamma-ray spectrometer

A large, 3200-kg (7000-lb) gamma-ray spectrometer was designed to move in a 1500 arc with an arc accuracy of 0.50, and to move radially over a distance of 650 mm (25 in.). The entire structure is aluminum rather than steel because of the high neutron background. The two-layer support accommodates rapid, accurate positioning of the spectrometer in both the rotational and radial directions within 0.1 mm (0.004 in.). All movements and positioning are computer-controlled. The centerline deviation over the entire surface is 0.25 mm (0.0100 in.). The bottom layer, called the table, permits arc motion. The table is a baseplate consisting of two 3.6-m {times} 1.2-m (12-ft {times} 4-ft) cast-aluminum jig plates. The top layer, called the sled, is an aluminum plate 2.12-m {times} 1.22-m (83.38-in. {times} 48-in.) wide, which provides for radial motion. Due to the large mass of the spectrometer and the accurate positioning required, air pads are used to facilitate movement. Hydraulic brakes are applied when the detector is in its rest position to comply with the seismic requirements of the installation.
Date: June 4, 1993
Creator: Pedersen, K. B.
Object Type: Article
System: The UNT Digital Library
Methyl chloride via oxyhydrochlorination of methane. Final quarterly technical report, July 1, 1992--September 30, 1992 (open access)

Methyl chloride via oxyhydrochlorination of methane. Final quarterly technical report, July 1, 1992--September 30, 1992

Work to develop a highly selective methyl chloride synthesis catalyst continued, but no stable catalyst with >80% selectivity at 20% methane exists yet. Effort was made on finalizing the pre- engineering scope definition of the Process Demonstration Unit. Natural gas purification, reactor, reactor effluent and MeCl purification, and anhydrous HCl recovery are discussed.
Date: March 4, 1993
Creator: Naasz, B.
Object Type: Report
System: The UNT Digital Library
The relativistic treatment of symmetric and asymmetric nuclear matter (open access)

The relativistic treatment of symmetric and asymmetric nuclear matter

In the framework of relativistic nuclear field theory the authors discuss and compare the different approaches in the treatment of nuclear-many-problem with inclusion of two-body correlations. The equations are solved self-consistently in the full Dirac space, so avoiding the ambiguities in the choice of the effective scattering amplitude. The results are compared with the standard method, where one only determines the scattering amplitude for positive energy spinors. Furthermore they tested the assumption of momentum independent self-energy. The results for asymmetric matter are in the structure similar to the outcome of the relativistic Hartree-Fock approximation, but differ from the nonrelativistic treatment. The agreement with the empirical values is quite satisfactory.
Date: November 4, 1993
Creator: Huber, H.; Weigel, M. K. & Weber, F.
Object Type: Article
System: The UNT Digital Library