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Detection of plutonium with the microwave plasma continuous emissions monitor

Description: The first successful detection of plutonium with a continuous microwave plasma emissions monitor has been demonstrated. Seven plutonium emission peaks in the 362 - 366 nm and 449 - 454 nm ranges were clearly observed. The strongest peak was at 453.62 nm. This peak and five of the other plutonium peaks were easily distinguishable from possible interference from iron emission peaks with a spectrometer resolution of 0.1 nm. 2 refs., 3 figs.
Date: September 1, 1995
Creator: Rhee, D.Y.; Woskov, P.P.; Gervais, K. & Surma, J.E.
Partner: UNT Libraries Government Documents Department

International Conference on Fundamental Aspects of Weak Interactions: Held at Brookhavan National Laboratory, September 9-11, 1963

Description: Report issued by the Brookhaven National Laboratory discussing papers presented at the International Conference on Fundamental Aspects of Weak Interactions. Each paper that was presented at the conference is included. This report includes tables, illustrations, and photographs.
Date: April 1964
Creator: Brookhaven National Laboratory
Partner: UNT Libraries Government Documents Department

Magnetic confinement experiment -- 1: Tokamaks

Description: This report reviews presentations made at the 15th IAEA Conference on Plasma Physics and Controlled Nuclear Fusion on experimental tokamak physics, particularly on advances in core plasma physics, divertor and edge physics, heating and current drive, and tokamak concept optimization.
Date: December 31, 1994
Creator: Goldston, R.J.
Partner: UNT Libraries Government Documents Department

Experimental Test of the Sweet-Parker Model of Magnetic Reconnection

Description: We report a quantitative experimental test of the Sweet-Parker model of magnetic reconnection in a controlled laboratory plasma. It is found that the observed reconnection rate cannot be explained by the Sweet-Parker model unless the model is generalized to incorporate compressibility, downstream pressure, and the effective resistivity. The latter is significantly enhanced over its classical values in the collisionless limit.
Date: September 1, 1997
Creator: Hsu, Scott; Ji, Hantao; Kulsrud, Russell & Yamada, Masaaki
Partner: UNT Libraries Government Documents Department

Synthesis of Ozone at Atmospheric Pressure by a Quenched Induction-Coupled Plasma Torch

Description: The technical feasibility of using an induction-coupled plasma (ICP) torch to synthesize ozone at atmospheric pressure is explored. Ozone concentrations up to ~250 ppm were produced using a thermal plasma reactor system based on an ICP torch operating at 2.5 MHz and ~11 kVA with an argon/oxygen mixture as the plasma-forming gas. A gaseous oxygen quench formed ozone by rapid mixing of molecular oxygen with atomic oxygen produced by the torch. The ozone concentration in the reaction chamber was measured by Fourier Transform infrared (FTIR) spectroscopy over a wide range of experimental configurations. The geometry of the quench gas flow, the quench flow velocity, and the quench flow rate played important roles in determining the ozone concentration. The ozone concentration was sensitive to the torch RF power, but was insensitive to the torch gas flow rates. These observations are interpreted within the framework of a simple model of ozone synthesis.
Date: January 1, 1998
Creator: Blutke, A.; Stratton, B.C.; Mikkelsen, D.R.; Vavruska, J. & Knight, R.
Partner: UNT Libraries Government Documents Department

Location and correction of 60 hz in the CEBAF injector

Description: CEBAF produces a continuous electron beam with an emittance of 2-3 nm-rad. Transverse low frequency magnetic oscillations act to dilute this emittance. These fields are typically associated with AC line conductors. The CEBAF injector is approximately 40 m long. To locate the source(s) of the beam motion, measured offsets were back propagated along the beamline using the DIMAD model. Field measurements were then made at the calculated field source positions and correlated with the measured effects. Corrections and final beam measurements were made to verify the corrections. 2 refs., 4 tabs.
Date: August 1, 1996
Creator: Legg, R.; Douglas, D.; Krafft, G.A. & Saulter, Q.
Partner: UNT Libraries Government Documents Department

Survey and analysis of line-frequency interference in the CEBAF accelerator

Description: Feedthrough of interference from the AC power line into accelerator components is a problem which in pulsed accelerators can be reduced by operation synchronous with the AC line. This means of avoiding line-frequency effects is ineffective for continuous wave machines such as the CEBAF accelerator. We have measured line-frequency perturbations at CEBAF both in beam position and energy by using the beam position monitor system as a multiple-channel sampling oscilloscope. Comparing these data against the measured static optics (taken synchronously with the AC line) we have been able to identify point sources of interference, and resolve line-synchronous variations in the beam energy at a level near 0.001%. 3 refs., 2 figs., 1 tab.
Date: December 31, 1995
Creator: Tiefenback, M.G. & Li, Rui
Partner: UNT Libraries Government Documents Department

Electrodeposition research progress report, March 1--31, 1948

Description: Plating of Postum out of Nitric Acid and Hydrofluoric Acid Solutions -- W. Abel and W. Raiff. Postum was plated out of 1.5 normal nitric acid and 1.0 normal hydrofluoric acid under similar conditions. The hydrofluoric acid plate was better appearing, and had a much higher curie density. However, neutron counts in these runs were quite similar. Neutron Counts -- W. Abel and W. Raiff. A study of the change of neutron counts over a period of time was started. Conversion of Active Hydrofluoric Acid Solutions to Hydrochloric Acid Solutions -- W. Raiff. A 99.99+ per cent conversion was effected. Conversion of Production Solutions to 1.0 Normal Hydrofluoric Add Solutions -- R. Bell. Good conversion has been achieved; however, further work needs to be done on complete change of postum from the production solution to 1.0 normal hydrofluoric acid solutions.
Date: December 31, 1948
Creator: Orban, E.
Partner: UNT Libraries Government Documents Department

Monsanto Chemical Company, Unit 3 progress report, January 16--31, 1948

Description: Solubilities -- Orban: The solubility of postum in various concentrations of nitric acid was determined at 25.4{degrees}C. Hydrofluoric and Trifluoroacetic Acids -- Abel and Raiff: Details of this work will be reported in the next Progress Report. Conversion of Nitric Acid Solutions to Hydrofluoric Acid Solutions -- Bell: Conversion of production solutions to hydrofluoric acid solutions was tried by precipitation with ammonium oxalate, aluminum hydroxide, ammonium hydroxide, and sodium carbonate. Silver and Teflon discs were used.
Date: December 31, 1948
Partner: UNT Libraries Government Documents Department

A Planar Quantum Transistor Based on 2D-2D Tunneling in Double Quantum Well Heterostructures

Description: We report on our work on the double electron layer tunneling transistor (DELTT), based on the gate-control of two-dimensional -- two-dimensional (2D-2D) tunneling in a double quantum well heterostructure. While previous quantum transistors have typically required tiny laterally-defined features, by contrast the DELTT is entirely planar and can be reliably fabricated in large numbers. We use a novel epoxy-bond-and-stop-etch (EBASE) flip-chip process, whereby submicron gating on opposite sides of semiconductor epitaxial layers as thin as 0.24 microns can be achieved. Because both electron layers in the DELTT are 2D, the resonant tunneling features are unusually sharp, and can be easily modulated with one or more surface gates. We demonstrate DELTTs with peak-to-valley ratios in the source-drain I-V curve of order 20:1 below 1 K. Both the height and position of the resonant current peak can be controlled by gate voltage over a wide range. DELTTs with larger subband energy offsets ({approximately} 21 meV) exhibit characteristics that are nearly as good at 77 K, in good agreement with our theoretical calculations. Using these devices, we also demonstrate bistable memories operating at 77 K. Finally, we briefly discuss the prospects for room temperature operation, increases in gain, and high-speed.
Date: December 14, 1998
Creator: Baca, W.E.; Blount, M.A.; Hafich, M.J.; Lyo, S.K.; Moon, J.S.; Reno, J.L. et al.
Partner: UNT Libraries Government Documents Department

Transmission electron microscopy study in-situ of radiation-induced defects in copper at elevated temperatures

Description: Neutrons and high-energy ions incident upon a solid can initiate a displacement collision cascade of lattice atoms resulting in localized regions within the solid containing a high concentration of interstitial and vacancy point defects. These point defects can collapse into various types of dislocation loops and stacking fault tetrahedra (SFT) large enough that their lattice strain fields are visible under diffraction-contrast imaging using a Transmission Electron Microscope (TEM). The basic mechanisms driving the collapse of point defects produced in collision cascades is investigated in situ with TEM for fcc-Cu irradiated with heavy (100 keV Kr) ions at elevated temperature. The isothermal stability of these clusters is also examined in situ. Areal defect yields were observed to decrease abruptly for temperatures greater than 300 C. This decrease in defect yield is attributed to a proportional decrease in the probability of collapse of point defects into clusters. The evolution of the defect density under isothermal conditions appears to be influenced by three different rate processes active in the decline of the total defect density. These rate constants can be attributed to differences in the stability of various types of defect clusters and to different loss mechanisms. Based upon observed stabilities, estimations for the average binding enthalpies of vacancies to SFT are calculated for copper.
Date: December 1, 1996
Creator: Daulton, T.L.; Kirk, M.A. & Rehn, L.E.
Partner: UNT Libraries Government Documents Department

Radiotoxicity of neptunium(V) and neptunium(V)-nitrilotriacetic acid (NTA) complexes towards Chelatobacter heintzii

Description: The objective of this work was to investigate the toxicity mechanisms of neptunium and the neptunium-NTA complex towards Chelatobacter heintzii. The results show that metal toxicity of aquo NpO{sub 2}{sup +} may significantly limit growth of Cl heintzii at free metal ion concentrations greater than {approx} 10{sup {minus}5} M. However, neptunium concentrations {ge} 10{sup {minus}4} M do not cause measurable radiotoxicity effects in C. heintzii when present in the form of a neptunium-NTA complex or colloidal/precipitated neptunium-phosphate. The neptunium-NTA complex, which is stable under aerobic conditions, is destabilized by microbial degradation of NTA. When phosphate was present, degradation of NTA led to the precipitation of a neptunium-phosphate phase.
Date: March 10, 1997
Creator: Banaszak, J.E.; Reed, D.T. & Rittmann, B.E.
Partner: UNT Libraries Government Documents Department

Effects of particle size on the desorption kinetics of water from Beulah-Zap lignite coal: Differential scanning calorimetry results

Description: The drying kinetics of water from three particle-sized Beulah-Zap lignite coal samples were probed using the differential scanning calorimetry technique at 295 < T < 480 K. The measurements undertaken under flowing N{sub 2} gas environment indicate that water is lost from this coal by two independent but simultaneously operative kinetic mechanisms. Our results suggest that the unimolecular decay kinetics are obeyed by those water molecules which are near the mouths of large pores and/or surround the coal particles. Most of the water, about 80% of the water lost in our experiments, was removed via a 2nd-order diffusion mechanism. As expected, the desorption activation energies of the 2nd-order diffusion kinetics were much larger than the decay mechanism`s activation energies. Our results also suggest, at least for particle sizes < 841 {mu}m, < 106 {mu}m, and < 37 {mu}m, that the coal particle size has little effect on the desorption activation barriers.
Date: March 1996
Creator: Dang, Yuhong; Malhotra, V. M. & Vorres, K. S.
Partner: UNT Libraries Government Documents Department

HRLEED study of the roughening transitions in Cu(110), Ni(110) and Ag(110) surfaces

Description: The authors present the results of High Resolution Low Energy Electron Diffraction (HRLEED) measurements of the thermal roughening transition on Cu(110), Ag(110) and Ni(110) surfaces. They performed careful spot profile intensity measurements as a function of temperature. They observed a proliferation of steps along the (110) and (001) directions. In addition a strong deviation from a Debye model was observed in the scattered intensity of the Bragg reflections. This deviation from the harmonic approximation occurs well below the roughening transition temperature. The behavior of the three metal surfaces is qualitatively similar except for the transition temperatures. Ni shows the highest transition temperature (1,300 K), Cu is intermediate (1,000 K) and Ag has the lowest temperature (730 K). Analyzing the behavior of the (00) reflection intensity, and the evolution of the line shape as a function of the temperature, they found clear evidence of a roughening transition at the (110) surface. A lineshape analysis of the (00) reflection shows the transition from a Lorentzian lineshape to a power law. They also proved, based on the experimental data and a recent theoretical model, that there is a tremendous increase in step density and a decrease in the average terrace size as the temperature increases. They used STM to corroborate the HRLEED results at room temperature. They found excellent agreement.
Date: December 1, 1996
Creator: Wang, K. & Montano, P.A.
Partner: UNT Libraries Government Documents Department

Catalytic pyrolysis of automobile shredder residue

Description: In the United States, approximately 10 million automobiles are scrapped and shredded each year. The mixture of plastics and other materials remaining after recovery of the metals is known as Automobile Shredder Residue (ASR). In 1994, about 3.5 million tons of ASR was produced and disposed of in landfills. However, environmental, legislative, and economic considerations are forcing the industry to search for recycling or other alternatives to disposal. Numerous studies have been done relating the ASR disposal problem to possible recycling treatments such as pyrolysis, gasification, co-liquefaction of ASR with coal, chemical recovery of plastics from ASR, catalytic pyrolysis, reclamation in molten salts, and vacuum pyrolysis. These and other possibilities have been studied intensively, and entire symposia have been devoted to the problem. Product mix, yields, toxicology issues, and projected economics of conceptual plant designs based on experimental results are among the key elements of past studies. Because the kinds of recycling methods that may be developed, along with their ultimate economic value, depend on a very large number of variables, these studies have been open-ended. It is hoped that it may be useful to explore some of these previously studied areas from fresh perspectives. One such approach, currently under development at Argonne National Laboratory, is the catalytic pyrolysis of ASR.
Date: July 1, 1995
Creator: Arzoumanidis, G.G.; McIntosh, M.J. & Steffensen, E.J.
Partner: UNT Libraries Government Documents Department

Designer carbons as potential anodes for lithium secondary batteries

Description: Carbons are the material of choice for lithium secondary battery anodes. Our objective is to use designed synthesis to produce a carbon with a predictable structure. The approach is to pyrolyze aromatic hydrocarbons within a pillared clay. Results from laser desorption mass spectrometry, scanning tunneling microscopy, X-ray diffraction, and small angle neutron scattering suggest that we have prepared disordered, porous sheets of carbon, free of heteroatoms. One of the first demonstrations of template-directed carbon formation was reported by Tomita and co-workers, where polyacrylonitrile was carbonized at 700{degrees}C yielding thin films with relatively low surface areas. More recently, Schwarz has prepared composites using polyfurfuryl alcohol and pillared clays. In the study reported here, aromatic hydrocarbons and polymers which do not contain heteroatoms are being investigated. The alumina pillars in the clay should act as acid sites to promote condensation similar to the Scholl reaction. In addition, these precursors should readily undergo thermal polymerization, such as is observed in the carbonization of polycyclic aromatic hydrocarbons.
Date: July 1, 1995
Creator: Winans, R.E.; Carrado, K.A. & Thiyagarajan, P.
Partner: UNT Libraries Government Documents Department

Engineering development of advanced physical fine coal cleaning technologies: Froth flotation. Quarterly technical progress report No. 26, January 1, 1995--March 31, 1995

Description: A study conducted by Pittsburgh Energy Technology Center of sulfur emissions from about 1,300 United States coal-fired utility boilers indicated that half of the emissions were the result of burning coals having greater than 1.2 pounds of SO{sub 2} per million BTU. This was mainly attributed to the high pyritic sulfur content of the boiler fuel. A significant reduction in SO{sub 2} emissions could be accomplished by removing the pyrite from the coals by advanced physical fine coal cleaning. An engineering development project was prepared to build upon the basic research effort conducted under a solicitation for research into Fine Coal Surface Control. The engineering development project is intended to use general plant design knowledge and conceptualize a plant to utilize advanced froth flotation technology to process coal and produce a product having maximum practical pyritic sulfur reduction consistent with maximum practical BTU recovery. The overall project scope of the engineering development project is to conceptually develop a commercial flowsheet to maximize pyritic sulfur reduction at practical energy recovery values. This is being accomplished by utilizing the basic research data on the surface properties of coal, mineral matter and pyrite obtained from the Coal Surface Control for Advanced Fine Coal Flotation Project, to develop this conceptual flowsheet. This progress report provides a summary of the technical work undertaken during this period, highlighting the major results. A brief description of the work done prior to this quarter is provided in this report under the task headings.
Date: July 1, 1995
Partner: UNT Libraries Government Documents Department

Dense inclined flows: Theory and experiments. Quarterly technical progress report, January 1, 1995--March 31, 1995

Description: Rapid, gravity-driven flows of granular materials down inclines pose a challenge to our understanding. Even in situations in which the flow is steady and two-dimensional, the details of how momentum and energy are balanced within the flow and at the bottom boundary are not well understood. Thus we have undertaken a research program integrating theory, computer simulation, and experiment that will focus on dense entry flows down inclines. The effort involves the development of theory informed by the results of simultaneous computer simulations and the construction, instrumentation, and use of an experimental facility in which the variables necessary to assess the success or failure of the theory can be measured. In the present reporting period, we have continued a series of measurements in the chute facility with a flat, frictional boundary. At several inclinations between 15.5{degrees} and 20{degrees}, and at several gate openings for each angle, we have measured mass flow rate and mass holdup, as well as granular temperature and collision frequency at the bottom wall of the chute. By recording simultaneously the collisional normal stress at the bottom wall and the mass holdup above it, the experiments reveal the fraction of the weight of particles that is supported by direct impact.
Date: August 1, 1995
Creator: Jenkins, J.T. & Louge, M.Y.
Partner: UNT Libraries Government Documents Department

Energy and environmental (JSR) research emphasizing low-rank coal

Description: The products of plastic thermal depolymerization can be used for the manufacture of new plastics or various other hydrocarbon-based products. One thermal depolymerization development effort is ongoing at the Energy & Environmental Research Center (EERC) of the University of North Dakota, under joint sponsorship of the American Plastics Council, the 3M corporation, and the Department of Energy. Thermal depolymerization process development began at the EERC with a benchscale program that ran from 9/92 to 6/93 (1). Testing was conducted in a 1-4-lb/hr continuous fluid-bed reactor (CFBR) unit using individual virgin resins and resin blends and was intended to determine rough operating parameters and product yields and to identify product stream components. Process variables examined included temperature and bed material, with a lesser emphasis on gas fluidization velocity and feed material mix. The following work was performed: (1) a short program to determine the suitability of using CaO in a postreactor, fixed bed for chlorine remediation, (2) thermal depolymerization of postconsumer plastics, and (3) testing of industrial (3M) products and wastes to determine their suitability as feed to a thermal depolymerization process. The involvement of DOE in the development of the plastics thermal depolymerization process has helped to facilitate the transfer of coal conversion technology to a new and growing technology area -- waste conversion. These two technology areas are complementary. The application of known coal conversion technology has accelerated the development of plastics conversion technology, and findings from the plastics depolymerization process development, such as the development of chlorine remediation techniques and procedures for measurement of organically associated chlorine, can be applied to new generations of coal conversion processes.
Date: December 1, 1994
Creator: Sharp, L.L.
Partner: UNT Libraries Government Documents Department

Biochemical basis of drought tolerance in hybrid Populus grown under field production conditions. CRADA final report

Description: The purpose of this cooperative effort was to assess the use of osmotically active compounds as molecular selection criteria for drought tolerance in Populus in a large-scale field trial. It is known that some plant species, and individuals within a plant species, can tolerate increasing stress associated with reduced moisture availability by accumulating solutes. The biochemical matrix of such metabolites varies among species and among individuals. The ability of Populus clones to tolerate drought has equal value to other fiber producers, i.e., the wood products industry, where irrigation is used in combination with other cultural treatments to obtain high dry weight yields. The research initially involved an assessment of drought stress under field conditions and characterization of changes in osmotic constitution among the seven clones across the six moisture levels. The near-term goal was to provide a mechanistic basis for clonal differences in productivity under various irrigation treatments over time.
Date: April 1, 1997
Creator: Tschaplinski, T.J.; Tuskan, G.A. & Wierman, C.
Partner: UNT Libraries Government Documents Department

A comparison study on the densification behavior and mechanical properties of gelcast vs conventionally formed B{sub 4}C sintered conventionally and by microwaves

Description: The utilization of microwave energy for reaching high temperatures necessary to densify B{sub 4}C powder is compared with conventional means of sintering by evaluating the mechanical properties after densification. Microwave energy has been shown to be an effective means for achieving high sintered densities, even though temperatures of {approximately} 2,250 C are required. In this study, green preforms of B{sub 4}C specimens were sintered by both conventional and microwave heating. This study also utilized an advanced forming method called ``Gelcasting`` developed at ORNL. Gelcasting is a fluid forming process whereby high solids suspensions of powders containing dissolved monomers are cast into a mold, then polymerized or ``gelled`` in situ. This investigation compares microstructures and mechanical properties of both Gelcast B{sub 4}C and ``conventionally`` die-pressed B{sub 4}C. The microstructures and final mechanical properties of B{sub 4}C specimens are discussed.
Date: June 1, 1996
Creator: Menchhofer, P.A.; Kiggans, J.O.; Morrow, M.S. & Schechter, D.E.
Partner: UNT Libraries Government Documents Department