Search Results

Advanced search parameters have been applied.
open access

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
open access

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
open access

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
open access

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
open access

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
open access

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
open access

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
open access

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
open access

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
open access

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
open access

Test report on the Abacus 30 kW bimode{reg_sign} inverter and maximum power tracker (MPT)

Description: Sandia National Laboratories conducts the photovoltaic balance of systems (BOS) program, which is sponsored by the US Department of Energy`s Office of Energy Management. Under this program, SNL lets commercialization contracts and conducts a laboratory program designed to advance BOS technology, improve BOS component reliability, and reduce the BOS life-cycle-cost. This report details the testing of the first large US manufactured hybrid inverter and its associated maximum power tracker.
Date: June 1, 1995
Creator: Bonn, R.; Ginn, J. & Zirzow, J.
Partner: UNT Libraries Government Documents Department
open access

Ultrahigh carbon steels, Damascus steels, and superplasticity

Description: The processing properties of ultrahigh carbon steels (UHCSs) have been studied at Stanford University over the past twenty years. These studies have shown that such steels (1 to 2.1% C) can be made superplastic at elevated temperature and can have remarkable mechanical properties at room temperature. It was the investigation of these UHCSs that eventually brought us to study the myths, magic, and metallurgy of ancient Damascus steels, which in fact, were also ultrahigh carbon steels. These steels were made in India as castings, known as wootz, possibly as far back as the time of Alexander the Great. The best swords are believed to have been forged in Persia from Indian wootz. This paper centers on recent work on superplastic UHCSs and on their relation to Damascus steels. 32 refs., 6 figs.
Date: April 1, 1997
Creator: Sherby, O. D. & Wadsworth, J.
Partner: UNT Libraries Government Documents Department
open access

An Investigation of Positrons Interacting With Solid Argon, Krypton and Xenon

Description: With this article we intend to shed some light on all the important characteristics of the up-to-date most efficient positron moderators, the rare gas solids. We stress on the importance of the impurities in the performance of the solid rare gas moderators. The impurity factor is linked with the crystalline changes to explain the effect of annealing, and demonstrate the role of impurities in the endurance. Significant increase in the low energy positron yield is observed after repeated anneals. The positron energy distributions from Ar, Kr, and Xe moderators are measured to be about 2 eV (FWHM).
Date: October 1, 1996
Creator: Petkov, M. P.; Roellig, L. O.; Troev, T. D. & Lynn, K. G.
Partner: UNT Libraries Government Documents Department
open access

Improvent of hydrogen solubility and entrainment in hydrocracker feedstocks. Quarterly report, April 1 - June 30, 1996

Description: The objective of this project is to determine the conditions for the hydrogen-heavy oil feed preparation so as to optimize the yield of hydrocracking reactions. Proper contacting of hydrogen with heavy oil on the catalytic bed is necessary to improve the yields of the hydrocracking reactions. It is most desirable to have the necessary amount of hydrogen available either in the dissolved or in entrained state, so that hydrogen diffusion to the reaction site does not provide rate controlling resistance to the overall rates of hydrocracking reactions. This project proposes to measure solubility and entrainment data for hydrogen in heavy oils at conditions such as in hydrocrackers, and investigate the improvement of these properties by usage of appropriate additives. Specifically, measurements will be carried out at temperatures up to 300{degrees} C and pressures up to 120 atmospheres. Correlations for solubility and entrainment kinetics will be developed from the measured data, and a method for estimating yield of hydrocracking reactions using these correlations will be suggested. Exxon Research and Engineering Company will serve as private sector collaborator providing A&T with test samples and some technical expertise that will assure successful completion of the project. The final experimental measurements for hydrogen solubility in hydrocarbons are in progress. The novel experimental apparatus has been successfully operated for these measurements. The calibration procedures and some of the initial data measurements are summarized.
Date: December 31, 1996
Creator: Kabadi, V. N.
Partner: UNT Libraries Government Documents Department
open access

Supporting document for the historical tank content estimate for AW-tank farm

Description: This Supporting Document provides historical in-depth characterization information on AW-Tank Farm, such as historical waste transfer and level data, tank physical information, temperature plots, liquid observation well plots, chemical analyte and radionuclide inventories for the Historical Tank Content Estimate Report for the Southeast Quadrant of the Hanford 200 Areas.
Date: March 6, 1997
Creator: Brevick, C.H., Stroup, J.L. & Funk, J.W., Fluor Daniel Hanford
Partner: UNT Libraries Government Documents Department
open access

Production of Gas-Solid Structures in Aluminum and Nickel Alloys by Gasar Processing

Description: Experimental data on directional and bulk solidification of hydrogen-charged samples of aluminum alloy A356 and nickel alloy Inconel 718 are discussed. The solidification structure of the porous zone is shown to be dependent on many process variables. Of these variables, hydrogen content in the melt prior to solidification, and furnace atmospheric pressure during solidification play the decisive role. Also important are the furnace atmosphere composition, the solidification velocity, and the temperature distribution of the liquid metal inside the mold.
Date: January 6, 1999
Creator: Apprill, J.M.; Baldwin, M.D.; Maguire, M.C.; Miszkiel, M.E. & Shapovalov, V.I.
Partner: UNT Libraries Government Documents Department
open access

Experimental tracking of the evolution of foam in porous media

Description: The authors discuss the experiments that have been done to track the effects of diffusion of gas in foams trapped in porous media. They describe several types of experiments and discuss the difficulties that prevent quantitative results from being obtained in most cases. However, the experiments do help them understand the physics and diffusion-driven coarsening of foams trapped in porous media. This understanding is necessary to simulate the behavior of these foams and predict the mobilization characteristics of foam in porous media. At the end of this paper, they compare the trends and predictions resulting from the experimental work to the predictions of the models which are presented elsewhere.
Date: July 1, 1996
Creator: Cohen, D; Patzek, T.W. & Radke, C.J.
Partner: UNT Libraries Government Documents Department
open access

The Top...is it There? A Survey of the CDF and D0 Experiments

Description: This paper describes: (1) features that the top quark must have if it exists, and how those features are inferred from various experiments; (2) how top quarks may be produced; (3) what must be accomplished to directly establish that the top quark has been produced in an experiment. Relevant features of the CDF and D0 detectors are described, as are methods useful in a top-quark search for identifying and detecting various kinds of particles. The author reviews data found by both CDF and D0, and discusses differences between the detectors and the data found with each. 57 figures.
Date: December 1, 1994
Creator: Tollestrup, A.V.
Partner: UNT Libraries Government Documents Department
open access

Neutron Activation Cool-down of the Tokamak Fusion Test Reactor

Description: Tokamak Fusion Test Reactor (TFTR) final operations and post-shutdown neutron activation measurements were made. Ionization chambers were used to follow TFTR activation during operations and after shutdown. Gamma-ray energy spectroscopy measurements were performed to characterize TFTR activation at accessible vessel-bays and on sample hardware removed from structures at various distances from the vessel. The results demonstrate long-lived activations from common, commercially available materials used in the fabrication and field engineering of TFTR. The measurements allow characterization of residual TFTR neutron activation, the projection of residual activation decay, and benchmarking of low activation issues simulations.
Date: June 10, 1998
Creator: Ascione, G.; Kugel, H.W.; Kumar, A. & Tilson, Jr, C.
Partner: UNT Libraries Government Documents Department
open access

Decomposition Studies of Triphenylboron, Diphenylborinic Acid and Phenylboric Acid in Aqueous Alkaline Solutions Containing Copper

Description: This report documents the copper-catalyzed chemical kinetics of triphenylboron, diphenylborinic acid and phenylboric acid (3PB, 2PB and PBA) in aqueous alkaline solution contained in carbon-steel vessels between 40 and 70 degrees C.
Date: February 11, 1997
Creator: Crawford, C.L. & Peterson, R. A.
Partner: UNT Libraries Government Documents Department
open access

Two-photon ionization and three-photon above-threshold ionization of argon

Description: Studies of nonlinear laser-matter interaction have been so far limited to wavelengths from the near ultraviolet to infrared, because of the low brightness of currently available sources outside this range. However nonlinear processes in the VUV/Soft X-ray domain would initiate multiphoton innershell spectroscopy, XUV nonlinear optics and applications of such processes to metrology. The probability of multiphoton transitions decreases rapidly with the number of photons involved. A typical two-photon bound-free transition has a rate of the order of .1 ps{sup {minus}1} at 10{sup 12} W.cm{sup {minus}2} and scales as the square of the intensity. Such an intensity is therefore required to saturate a two-photon transition with a 100 fs pulse. This is difficult to achieve with the present state-of-the-art techniques for producing intense XUV pulses. To the authors knowledge, only two cases of such transitions have been reported so far. The first one is a two-photon ionization of argon by the third harmonic of a KrF laser. Since the photon energy (15 eV) is just below the ionization energy (15.75 eV) for argon, the transition is quasi-resonant. The second case is a two-photon ionization of helium by the 9th harmonic of a Ti:S laser. In the latter case an autocorrelation measurement of the harmonic pulse has been reported. In the present work, the authors report on two-photon ionization of argon at 133 nm (9.3 eV) from the third harmonic of a frequency doubled Ti:S laser, and a three-photon above-threshold ionization involving two 9.3 eV photons and one 3.1 eV photon.
Date: March 1, 1998
Creator: Bouhal, A.; Hamoniaux, G.; Mysyrowicz, A.; Antonetti, A.; Breger, P.; Agostini, P. et al.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen