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Control of triacylglycerol biosynthesis in plants (open access)

Control of triacylglycerol biosynthesis in plants

Seeds of most species of the Umbelliferae (Apiaciae), Araliaceae, and Garryaceae families are characterized by their high content of the unusual C[sub 18] monounsaturated fatty acid petroselinic acid (18:l[Delta][sup 6cis]). Prior to a recent report of this lab, little was known of the biosynthetic origin of the cis[Delta][sup 6] double bond of petroselinic acid. Such knowledge may be of both biochemical and biotechnological significance. Because petroselinic acid is potentially the product of a novel desaturase, information regarding its synthesis may contribute to an understanding of fatty acid desaturation mechanisms in plants. Through chemical cleavage at its double bond, petroselinic acid can be used as a precursor of lauric acid (12:0), a component of detergents and surfactants, and adipic acid (6:0 dicarboxylic), the monomeric component of nylon 6,6. Therefore, the development of an agronomic source of an oil rich in petroselinic acid is of biotechnological interest. As such, studies of petroselinic acid biosynthesis may provide basic information required for any attempt to genetically engineer the production and accumulation of this fatty acid in an existing oilseed.
Date: January 31, 1993
Creator: unknown
System: The UNT Digital Library
Revitalizing a mature oil play: Strategies for finding and producing unrecovered oil in Frio Fluvial-Deltaic reservoirs of South Texas (open access)

Revitalizing a mature oil play: Strategies for finding and producing unrecovered oil in Frio Fluvial-Deltaic reservoirs of South Texas

During this second project quarter, screening of South Texas fields within the Frio Fluvial-Deltaic Sandstone/Vicksburg Fault Zone oil play was completed. Fields were to identify reservoirs that have a large remaining oil resource, are in danger of premature abandonment, and have geological and production data in sufficient quantity and of suitable quality to facilitate advanced reservoir characterization studies (subtask 1). Two fields have been selected for inclusion in this study: Tijerina-Canales-Blucher (T.C.B.) Field, located in the northern portion of the trend in Jim Wells County, and Rincon Field, located to the south in Starr County. Current plans are to incorporate data from both fields in our reservoir characterization and targeted resource addition studies. Project members met with operators of both fields to review available geologic and production field data and discuss our research plans. The collection of detailed geologic and production data required for the initial reservoir characterization studies (subtask 2) is currently underway. Details outlining specifics of project accomplishments for this quarter are provided.
Date: March 31, 1993
Creator: Tyler, N.
System: The UNT Digital Library
Study of Intermediates From Transition Metal Excited-State Electron- Transfer Reactions (open access)

Study of Intermediates From Transition Metal Excited-State Electron- Transfer Reactions

Progress on 6 projects is reported: excited state absorption spectrum of Ru(bpy)[sub 3][sup 2+], solvent cage model for electron transfer quenching, reductive quenching of [sup *]Cr(III) complexes, solution medium effects in oxidative quenching of [sup *]Ru(II) complexes, photosensitized oxidation of phenol in aqueous solution, and quenching of Ru(II) complexes by oxygen.
Date: March 31, 1993
Creator: Hoffman, M. Z.
System: The UNT Digital Library
Development and use of an apparatus to measure the dynamic surface properties of coal-water slurry fuels for applications to atomization characteristics (open access)

Development and use of an apparatus to measure the dynamic surface properties of coal-water slurry fuels for applications to atomization characteristics

The Texas A M University (TAMU) has been awarded a DOE contract to study dynamic properties and atomization characteristics of coal-water slurry (CWS) fuels. Additives are essential for better mixing and stable suspension of coal powders and these additives change CWS properties. Dynamic properties will have major effects on CWS fuel atomization, which constitutes highly dynamic processes, and will determine the combustion as well as the pollutant formation behaviors. The dynamic surface tension of CWS fuels can be much higher than the corresponding static surface tension. Experimental study of correlating the atomization characteristics and dynamic properties of CWS fuels will be performed during the contract period. The research projects consists of five tasks. Task 1 selects appropriate additives and surfactants for CWS fuels by measuring the stabilizing characteristics and critical micelle concentrations (CMC). Task 2 implements the dynamic surface tensiometer operating based on the formation of maximum bubble pressure. Task 3 measures dynamic properties of CWS fuels as functions of bubble frequency while the fuel parameters are varied. The fuel parameters include coal loading, type of stabilizer and type of surfactant. Task 4 will devise a CWS fuel spray system and Task 5 will measure the spray droplet sizes using …
Date: January 31, 1993
Creator: Kihm, K.D.
System: The UNT Digital Library
Application of magnetomechanical hysteresis modeling of magnetic techniques for monitoring neutron embrittlement and biaxial stress (open access)

Application of magnetomechanical hysteresis modeling of magnetic techniques for monitoring neutron embrittlement and biaxial stress

Research was done on the biaxial stress problem accomplished in the first half of the second year. All of the work done was preparatory to magnetic measurements. Issues addressed were: construction of a model for extracting changes in the magnetic properties of a specimen from the readings of an indirect sensor; initial development of a model for how biaxial stress alters the intrinsic magnetic properties of thespecimen; use of finite element stress analysis modeling to determine a detailed shape for the cruciform biaxial stress specimen; and construction of the biaxial stress loading apparatus.
Date: January 31, 1993
Creator: Sablik, M.J.; Kwun, H. & Burkhardt, G.L.
System: The UNT Digital Library
SET Careers Program: An interactive science, engineering, and technology career education exhibit. [A brief summary report] (open access)

SET Careers Program: An interactive science, engineering, and technology career education exhibit. [A brief summary report]

The New York Hall of Science, in response to the national crisis in education and employment in science and engineering, is developing and pilot testing a unique, interactive, video-based, hypermedia series on energy-related and other science and engineering careers for middle and junior high school students. Working in collaboration with the Consortium for Mathematics and its Applications (COMAP) and the Educational Film Center (EFC), this pilot-demonstration phase will last 14 months, during which time the basic design, production, and testing of eight science and engineering career modules (video and software) will be completed and installed as an interactive educational exhibit at the New York Hall of Science. This career education package will then be distributed to other science technology centers nationwide.
Date: March 31, 1993
Creator: Cole, P.R.
System: The UNT Digital Library
Performance of CVR coatings for PBR fuels (open access)

Performance of CVR coatings for PBR fuels

As part of the component development process for the particle bed reactor (PBR), it is necessary to develop coatings for fuel particles which will be time and temperature stable. These coatings must not only protect the particle from attack by the hydrogen coolant, but must also help to maintain the bed in a coolable geometry and mitigate against fission product release. In order to develop these advanced coatings, a process to produce chemical vapor reaction (CVR) coatings on fuel for PBRs has been developed. The initial screening tests for these coatings consisted of testing in flowing hot hydrogen at one atmosphere. Surrogate fuel particles consisting of pyrolytic graphite coated graphite particles have been heated in flowing hydrogen at constant temperature. The carbon loss from these particles was measured as a function of time. Exposure temperatures ranging from 2,500 to 3,000 K were used and samples were exposed for up to 14 minutes in a cyclical fashion, cooling to room temperature between exposures. The rate of weight loss measured as a function of time is compared to that from other tests of coated materials under similar conditions. Microscopic examination of the coatings before and after exposure was also conducted and these …
Date: December 31, 1993
Creator: Adams, J. W.; Barletta, R. E.; Svandrlik, J. & Vanier, P. E.
System: The UNT Digital Library
Studies in physico-chemical hydrodynamics of extended systems. Annual progress report, November 1, 1993--October 31, 1994 (open access)

Studies in physico-chemical hydrodynamics of extended systems. Annual progress report, November 1, 1993--October 31, 1994

The object of the proposed research program is a unified theoretical approach to the description of a variety of physico-chemical hydrodynamic systems characterized by a significant disparity between the spatial scales involved. By appropriately performed averaging over short scales, one may considerably simplify the original problem, sometimes even lowering its effective dimensionality, and thereby making the latter quite tractable either analytically or numerically. Specifically, the author plans to study: (1) the hydrodynamic aspects of flameholding and flammability in premixed gas flames, (2) large-scale structures in Rayleigh-Benard-Marangoni convection in nonreactive and reactive liquid layers, (3) nonlinear dynamics of interfacial instabilities dominated by viscosity effects, and (4) negative viscosity effects and formation of large-scale structures in liquid layers driven at small scales.
Date: December 31, 1993
Creator: Sivashinsky, G. I.
System: The UNT Digital Library
Stability and precipitation kinetics in Si{sub 1{minus}y}C{sub y}/Si and Si{sub 1{minus}x{minus}y}Ge{sub x}C{sub y}/Si heterostructures prepared by solid phase epitaxy (open access)

Stability and precipitation kinetics in Si{sub 1{minus}y}C{sub y}/Si and Si{sub 1{minus}x{minus}y}Ge{sub x}C{sub y}/Si heterostructures prepared by solid phase epitaxy

This study investigates the stability of metastable Si{sub 1{minus}y}C{sub y}/Si heterostructures during rapid thermal annealing (RTA) over a temperature range of 1,000--1,150 C. Heterostructures of Si{sub 1{minus}y}C{sub y}/Si and Si{sub 1{minus}x{minus}y}Ge{sub x}C{sub y}/Si (x {equals} 0.77, Y {<=} .0014) were formed by solid phase epitaxy from C implanted, preamorphized substrates using a 30 minute 700 C anneal in N{sub 2}. The occupancy of C in substitution lattice sites was monitored by Fourier Transform Infrared Absorption spectroscopy. The layer strain was monitored by rocking curve X-ray diffraction and the structural changes in the layers were determined using plan-view and X-sectional transmission electron microscopy (TEM). For anneals of 1,150 C or above, all the substitutional C was lost from the Si lattice after 30 seconds. TEM verified that the strain relaxation was the result of C precipitating into highly aligned {beta}SiC particles rather than by the formation of extended defects. No nucleation barrier was observed for the loss of substitutional C. Preliminary results will also be discussed for Si{sub 1{minus}x{minus}y}Ge{sub x}C{sub y}/Si heterostructures where there is the additional factor of the competition between strain energy and the chemical driving forces.
Date: December 31, 1993
Creator: Strane, J. W.; Picraux, S. T.; Stein, H. J.; Lee, S. R.; Candelaria, J.; Theodore, D. et al.
System: The UNT Digital Library
Demonstration testing and evaluation of in situ soil heating: Management Plan (open access)

Demonstration testing and evaluation of in situ soil heating: Management Plan

This document is the Management Plan for US DOE contract entitled, {open_quotes}Demonstration, Testing and Evaluation of In Situ Soil Heating,{close_quotes} Contract No. DE-AC05-93OR22160, IITRI Project No. C06787. In this project IITRI will demonstrate an in situ soil heating technology for the removal of hazardous organic contaminants present in the soil. In situ heating will be accomplished by the application of 60 Hz ac power to the soil. The soil will be heated to a temperature of about 90{degrees}C. This technology is suited for the removal of those organic compounds which have a normal boiling point in the range of 100{degrees} to 210{degrees}C, or else for those which exhibit a pure component vapor pressure of at least 10 mm Hg in the 90{degrees} to 100{degrees}C temperature range. For example, perchloroethylene, dichlorobenzene, trichlorobenzene, etc. may be removed by in situ ac heating. It is planned to demonstrate the technology by heating approximately 400 tons of soil in the K-1070 Classified Burial Ground located at DOE`s K-25 Site located in Oak Ridge, TN. It is estimated that the heating portion of the demonstration will take approximately 3 weeks at an average power input rate of 150 to 175 kW. IITRI expects to spend …
Date: December 31, 1993
Creator: Dev, H.
System: The UNT Digital Library
New high temperature plasmas and sample introduction systems for analytical atomic emission and mass spectrometry. Progress report: January 1, 1993--December 31, 1993 (open access)

New high temperature plasmas and sample introduction systems for analytical atomic emission and mass spectrometry. Progress report: January 1, 1993--December 31, 1993

In this research, new high-temperature plasmas and new sample introduction systems are explored for rapid elemental and isotopic analysis of gases, solutions, and solids using mass spectrometry and atomic emission spectrometry. During the period January 1993--December 1993, emphasis was placed on (a) analytical investigations of atmospheric-pressure helium inductively coupled plasma (He ICP) that are suitable for atomization, excitation, and ionization of elements possessing high excitation and ionization energies; (b) simulation and computer modeling of plasma sources to predict their structure and fundamental and analytical properties without incurring the enormous cost of experimental studies; (c) spectrosopic imaging and diagnostic studies of high-temperature plasmas; (d) fundamental studies of He ICP discharges and argon-nitrogen plasma by high-resolution Fourier transform spectrometry; and (e) fundamental and analytical investigation of new, low-cost devices as sample introduction systems for atomic spectrometry and examination of new diagnostic techniques for probing aerosols. Only the most important achievements are included in this report to illustrate progress and obstacles. Detailed descriptions of the authors` investigations are outlined in the reprints and preprints that accompany this report. The technical progress expected next year is briefly described at the end of this report.
Date: December 31, 1993
Creator: Montaser, A.
System: The UNT Digital Library
Research activities of Martin C. Casdagli at SFI September 1989--May 1991 (open access)

Research activities of Martin C. Casdagli at SFI September 1989--May 1991

My research over this period has focused on the theory and application of non-linear time series forecasting. The purpose of time series forecasting is to predict apparently random behavior about which we have little or no knowledge. A time series is a set of values that change in time, for example, daily stock market prices for a given set of firms, or the volume of the polar ice caps over the last two million years. Recent developments in the understanding of chaotic dynamical systems have stimulated new approaches to time series analysis. These results raise the possibility that apparently random behavior may essentially be the consequence of chaotic behavior of deterministic equations with a small number of variables. My main research effort has been to develop a theory of nonlinear time series forecasting which applies to chaotic time series with low levels of observational noise. I have also developed a new algorithm for analyzing experimental time series data in order to determine whether a nonlinear deterministic, as opposed to nonlinear stochastic model is an appropriate description of the data, and have applied this algorithm to a wide range of time series data. In addition to involvement in these and other …
Date: December 31, 1993
Creator: unknown
System: The UNT Digital Library
On the nature of striae in strontium barium niobate (open access)

On the nature of striae in strontium barium niobate

Strontium barium niobate crystals were grown by the Czochralski technique. These crystals were 15--20 mm in diameter and 25 to 75 mm long. Two types stride, designated as coarse and fine, were characterized. The coarse stride are optically dense and are spaced by 100 to 500 {mu}m apart; the fine striae are optically less dense and spaced 5--50 {mu}m apart. The origins of the stride are attributed to thermal fluctuations in the melt related to the control system and to rotation of the growing crystal in non-isothermal radial gradients. Analysis of the crystals would indicated that the coarse striae may contain increased concentrations of sodium.
Date: December 31, 1993
Creator: Monchamp, R. R.; Mihalik, G. B. & Franks, L. A.
System: The UNT Digital Library
Theoretical reversed field pinch and tokamak studies. Progress report, November 1, 1992--June 10, 1993 (open access)

Theoretical reversed field pinch and tokamak studies. Progress report, November 1, 1992--June 10, 1993

This report discusses the following topics: fluctuation suppression by electrostatic current injection; pulsed poloidal current drive; effect of current drive on fluctuations; rf current drive in the RFP; development of a hyper-dissipation algorithms; and interacting magnetic islands.
Date: December 31, 1993
Creator: unknown
System: The UNT Digital Library
Sonic Enhanced Ash Agglomeration and Sulfur Capture. Technical progress report, July 1993--September 1993 (open access)

Sonic Enhanced Ash Agglomeration and Sulfur Capture. Technical progress report, July 1993--September 1993

A major concern with the utilization of coal in directly fired gas turbines is the control of particulate emissions and reduction of sulfur dioxide, and alkali vapor from combustion of coal, upstream of the gas turbine. Much research and development has been sponsored on methods for particulate emissions control and the direct injection of calcium-based sorbents to reduce SO{sub 2} emission levels. The results of this research and development indicate that both acoustic agglomeration of particulates and direct injection of sorbents have the potential to become a significant emissions control strategy. The Sonic Enhanced Ash Agglomeration and Sulfur Capture program focuses upon the application of an MTCI proprietary invention (Patent No. 5,197,399) for simultaneously enhancing sulfur capture and particulate agglomeration of the combustor effluent. This application can be adapted as either a ``hot flue gas cleanup`` subsystem for the current concepts for combustor islands or as an alternative primary pulse combustor island in which slagging, sulfur capture, particulate agglomeration and control, and alkali gettering as well as NO{sub x} control processes become an integral part of the pulse combustion process. The goal of the program is to support the DOE mission in developing coal-fired combustion gas turbines. In particular, the …
Date: December 31, 1993
Creator: unknown
System: The UNT Digital Library
Nuclear reaction analysis of hydrogen in SSC beam pipe materials (open access)

Nuclear reaction analysis of hydrogen in SSC beam pipe materials

To control the photodesorption of molecular hydrogen, it is advantageous to reduce the amount of hydrogen in candidate SSC beam pipe materials and identify those procedures that: (1) lead to contamination of the beam pipe surface or materials, (2) would reduce the amount of hydrogen on the surface or in the bulk and (3) could be used for in-situ cleaning during Collider assembly or during Collider maintenance. Nuclear Reaction Analysis (NRA) can be used to quantitatively measure the amount of hydrogen on the surface or within half a micron of the surface. The present report discusses data that has been obtained for candidate SSC beam pipe materials (Nitronix 40 Stainless Steel, Nitronix 40 SS coated with electrodeposited copper (Silvex process)), oxygen-free high conductivity copper (Hitachi 101 OFHC) and several miscellaneous samples. The work demonstrates the potential of the technique for characterizing the hydrogen concentration of accelerator beam pipe materials, for assisting in the development of better vacuum system materials for TeV-scale accelerators, and for the development of better beam pipe construction or maintenance procedures for future accelerator projects.
Date: December 31, 1993
Creator: Ruckman, M. W.; Strongin, M. & Lanford, W. A.
System: The UNT Digital Library
Na/Ca catalyzation of Illinois coals for gasification. Final technical report, September 1, 1992--August 31, 1993 (open access)

Na/Ca catalyzation of Illinois coals for gasification. Final technical report, September 1, 1992--August 31, 1993

Gasification for power generation via IGCC processes is expected to become an important market for high sulfur Illinois Basin coals. Fluid-bed gasifiers have significant advantages over entrained flow processes. These advantages include ease of control, large turndown capacity, high thermal efficiency, and moderate oxygen and steam requirements. Three of the most pressing technical problems in fluid-bed gasification of Illinois coals are the caking tendency, high sulfur content, and low carbon conversion and consequent large char recycle required in most systems. This program explores the use of gasification catalysts to attack these three problems. The catalysts are sodium/calcium mixtures. Another advantage of using catalysts is that gasification temperature might be lowered, leading to less expensive materials of construction and a reduction in alkali vaporization. The results of this study indicate that these catalysts can reduce or eliminate the caking of Illinois coals. Loadings below 1 weight % were effective if the catalyst was added by impregnation at low pH (below about 5). An Na/Ca molar ratio of greater than 1 also leads to lower catalyst requirement.
Date: December 31, 1993
Creator: Jha, M. C. & McCormick, R. L.
System: The UNT Digital Library
Power systems development facility. Quarterly technical progress report, July 1--September 30, 1993 (open access)

Power systems development facility. Quarterly technical progress report, July 1--September 30, 1993

This quarterly technical progress report summarizes work completed during the Second Quarter of the Second Budget Period, July 1 through September 30, 1993, under the Department of Energy (DOE) Cooperative Agreement No. DE-FC21-90MC25140 entitled ``Hot Gas Cleanup Test Facility for Gasification and Pressurized Combustion.`` The objective of this project is to evaluate hot gas particle control technologies using coal-derived gas streams. This will entail the design, construction, installation, and use of a flexible test facility which can operate under realistic gasification and combustion conditions. The major particulate control device issues to be addressed include the integration of the particulate control devices into coal utilization systems, on-line cleaning techniques, chemical and thermal degradation of components, fatigue or structural failures, blinding, collection efficiency as a function of particle size, and scaleup of particulate control systems to commercial size. The conceptual design of the facility was extended to include a within scope, phased expansion of the existing Hot Gas Cleanup Test Facility Cooperative Agreement to also address systems integration issues of hot particulate removal in advanced coal-based power generation systems. This expansion included the consideration of the following modules at the test facility in addition to the existing Transport Reactor gas source and …
Date: December 31, 1993
Creator: unknown
System: The UNT Digital Library
[Experiment studies of electron-positron interactions at the Stanford Linear Accelerator Center]. Progress report, calendar year 1993 (open access)

[Experiment studies of electron-positron interactions at the Stanford Linear Accelerator Center]. Progress report, calendar year 1993

The High Energy Physics group at the University of Massachusetts has continued its` program of experimental studies of electron-positron interactions at the Stanford Linear Accelerator Center (SLAC). The group activities have included: analysis of data taken between 1982 and 1990 with the TPC detector at the PEP facility, continuing data collection and data analysis using the SLC/SLD facility, planning for the newly approved B-factory at SLAC, and participation in design studies for future high energy linear colliders. This report will briefly summarize these activities.
Date: December 31, 1993
Creator: Hertzbach, S. S. & Kofler, R. R.
System: The UNT Digital Library
[Toxicity studies of mild gasification products: Quarterly technical progress report, April--June 1993] (open access)

[Toxicity studies of mild gasification products: Quarterly technical progress report, April--June 1993]

The major hypothesis of carcinogenesis is that malignancy is due to an alteration (mutation) of the genetic material in a somatic cell. Reactive electrophilic metabolites are generated from many chemicals by the action of endogenous mixed function oxidases. These reactive metabolites may bind to cellular macromolecules, such as DNA, and can, therefore, initiate a mutagenic or carcinogenic event. Prokaryotes and non-mammalian eukaryotes are used in mutation assays, while cultured mammalian cells are generally used for mutagenic as well as clastogenic tests examining alterations and damage to the DNA and/or chromosomes of somatic cells. One of the first mammalian cell lines used in genotoxicity studies is V79, which was derived from Chinese hamster lung cells. According to the test plan on toxicity studies of mild gasification products, mammalian cell in vitro assays are to be performed on selected samples displaying mutagenic activity in the Ames assay. The results of the Ames testing of the mild gasification sample IST {number_sign}10 indicate significant mutagenic activity. Hence, assays for the induction of gene mutation, sister chromatid exchange and micronucleus formation in V79 cells have been carried out for the sample. This paper reports the results of these assays.
Date: December 31, 1993
Creator: unknown
System: The UNT Digital Library
Two-phase power-law modeling of pipe flows displaying shear-thinning phenomena (open access)

Two-phase power-law modeling of pipe flows displaying shear-thinning phenomena

This paper describes work in modeling concentrated liquid-solids flows in pipes. COMMIX-M, a three-dimensional transient and steady-state computer program developed at Argonne National Laboratory, was used to compute velocities and concentrations. Based on the authors` previous analyses, some concentrated liquid-solids suspension flows display shear-thinning rather than Newtonian phenomena. Therefore, they developed a two-phase non-Newtonian power-law model that includes the effect of solids concentration on solids viscosity. With this new two-phase power-law solids-viscosity model, and with constitutive relationships for interfacial drag, virtual mass effect, shear lift force, and solids partial-slip boundary condition at the pipe walls, COMMIX-M is capable of analyzing concentrated three-dimensional liquid-solids flows.
Date: December 31, 1993
Creator: Ding, Jianmin; Lyczkowski, R. W. & Sha, W. T.
System: The UNT Digital Library
Transient studies of low temperature catalysts for methane conversion. Quarterly technical progress report, June 30, 1993--September 30, 1993 (open access)

Transient studies of low temperature catalysts for methane conversion. Quarterly technical progress report, June 30, 1993--September 30, 1993

This report summarizes studies on the oxidative coupling of methane on metallo oxide catalysts. A previous report summarized the results on the partial oxidation of methane on Li promoted VPO{sub 4} catalysts and the role of the Li promotion on increasing formaldehyde selectivity. The results of such study have been summarized in a paper submitted for publication. Given the relatively low conversion of methane and the low formaldehyde selectivity, it was decided to continue studying the oxidative coupling of methane on metallo oxide catalysts, which was one of the objective of this project. Results are reported for a LaCoO{sub 3} and LaNiO{sub 3} both unpromoted and Li promoted.
Date: December 31, 1993
Creator: Wolf, E. E.
System: The UNT Digital Library
Structural analysis of amorphous phosphates using high performance liquid chromatography (open access)

Structural analysis of amorphous phosphates using high performance liquid chromatography

Determining the atomic-scale structure of amorphous solids has proven to be a formidable scientific and technological problem for the past 100 years. The technique of high-performance liquid chromatography (HPLC) provides unique detailed information regarding the structure of partially disordered or amorphous phosphate solids. Applications of the experimental technique of HPLC to phosphate solids are reviewed, and examples of the type of information that can be obtained with HPLC are presented. Inorganic phosphates encompass a large class of important materials whose applications include: catalysts, ion-exchange media, solid electrolytes for batteries, linear and nonlinear optical components, chelating agents, synthetic replacements for bone and teeth, phosphors, detergents, and fertilizers. Phosphate ions also represent a unique link between living systems and the inorganic world.
Date: December 31, 1993
Creator: Sales, B. C.; Boatner, L. A.; Chakoumakos, B. C.; McCallum, J. C.; Ramey, J. O. & Zuhr, R. A.
System: The UNT Digital Library
A 200 kV fast rise time, low jitter, trigger system with magnetic pulse sharpener (open access)

A 200 kV fast rise time, low jitter, trigger system with magnetic pulse sharpener

The DARHT Facility is being designed at Los Alamos National Laboratory to produce high resolution flash radiographs of hydrodynamic experiments. Two linear induction accelerators (LIA), each in the range of 16 to 20 MeV, will be used to produce intense bremsstrahlung X-ray pulses of short duration (60 ns flat top). Each LIA will produce a 3 kA, high brightness, electron beam using a 4 MeV injector and a series of 250 kV induction cells. Technology demonstration of key accelerator subsystems is under progress at the DARHT Integrated Test Stand (ITS). The eight inductions cells present in the ITS are driven by a Maxwell prototype Induction Cell Pulsed Power Supply (ICPPS) which provides 250 kV, 70ns pulses via four Blumleins. Each Blumlein drives two cells and is triggered using independently controlled trigger units. This turnkey DARHT Trigger System, consisting of four separate trigger units, provides 200 kV trigger pulses with low jitter and fast rise time to each of the four Blumlein coaxial spark gaps. Details of the trigger system design and results obtained during extensive testing at Maxwell are described.
Date: December 31, 1993
Creator: Jaitly, N. C.; Ramrus, A.; Coleman, M. D.; Earley, L. M.; Downing, J. N.; Reisch, H. H. et al.
System: The UNT Digital Library