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265,543 Matching Results

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Results: 1 - 24 of 265,543 next
Best Match Title Creator Date Created (Newest) Date Created (Oldest) Date Added (Newest) Date Added (Oldest)
Biliary Excretion of /Sup 99m/Tc Albumin Microaggregate Degradation Products (a Method for Measuring Kupffer Cell Digestive Function.). (open access)

Biliary Excretion of /Sup 99m/Tc Albumin Microaggregate Degradation Products (a Method for Measuring Kupffer Cell Digestive Function.).

The rapid metabolism of radioactive albumin colloids used for liver-spleen-bone marrow scanning radiation exposure to these organs and permits one to study the proteolytic digestive capacity of the reticuloendothial system (RES)
Date: October 31, 1971
Creator: Kitani, K. & Taplin, G. V.
Object Type: Report
System: The UNT Digital Library
A unified theory of resonant excitation of kinetic ballooning modes by energetic ions/alpha particles in tokamaks (open access)

A unified theory of resonant excitation of kinetic ballooning modes by energetic ions/alpha particles in tokamaks

A complete theory of wave-particle interactions is presented whereby both circulating and trapped energetic ions can destabilize kinetic ballooning modes in tokamaks. Four qualitatively different types of resonances, involving wave-precessional drift, wave-transit, wave-bounce, and precessional drift-bounce interactions, are identified, and the destabilization potential of each is assessed. For a characteristic slowing-down distribution function, the dominant interaction is that which taps those resonant ions with the highest energy. Implications of the theory for present and future generation fusion experiments are discussed. 16 refs.
Date: October 1, 1991
Creator: Biglari, H. & Chen, L.
Object Type: Report
System: The UNT Digital Library
Non-linear instability of DIII-D to error fields (open access)

Non-linear instability of DIII-D to error fields

Otherwise stable DIII-D discharges can become nonlinearly unstable to locked modes and disrupt when subjected to resonant m = 2, n = 1 error field caused by irregular poloidal field coils, i.e. intrinsic field errors. Instability is observed in DIII-D when the magnitude of the radial component of the m = 2, n = 1 error field with respect to the toroidal field is B{sub r21}/B{sub T} of about 1.7 {times} 10{sup {minus}4}. The locked modes triggered by an external error field are aligned with the static error field and the plasma fluid rotation ceases as a result of the growth of the mode. The triggered locked modes are the precursors of the subsequent plasma disruption. The use of an n = 1 coil'' to partially cancel intrinsic errors, or to increase them, results in a significantly expanded, or reduced, stable operating parameter space. Precise error field measurements have allowed the design of an improved correction coil for DIII-D, the C-coil'', which could further cancel error fields and help to avoid disruptive locked modes. 6 refs., 4 figs.
Date: October 1, 1991
Creator: La Haye, R. J. & Scoville, J. T.
Object Type: Article
System: The UNT Digital Library
Fifth high-energy heavy-ion study (open access)

Fifth high-energy heavy-ion study

This was the fifth of a continuing series of summer studies held at LBL to discuss high energy heavy ion collisions. Recently, a similar meeting has been held on alternate years at GSI (Darmstadt); and, in 1979, we held a meeting at LBL exclusively devoted to ultra-relativistic nuclear collisions. Two new features distinguish this study from earlier meetings in the series. First, the energy range for discussion was broadened by including collisions from about 20 MeV/nucleon to the highest available in the cosmic radiation. The lower range, particularly below 100 MeV/nucleon, will be under intense study in the near future with machines such as the upgraded Bevalac, Michigan State University Superconducting Cyclotron, GANIL in France, and the SC at CERN. Recently, the high energy collision regime has been expanded by the successful operation of the CERN ISR with alpha particles. Second, in addition to an extensive program of invited talks, we decided for the first time to actively solicit contributions. Forty-seven individual items from the conference were prepared separately for the data base. (GHT)
Date: October 1, 1981
Creator: unknown
Object Type: Article
System: The UNT Digital Library
Radon alpha-track survey of a potential geothermal resource area. [Buffalo Valley, Nevada] (open access)

Radon alpha-track survey of a potential geothermal resource area. [Buffalo Valley, Nevada]

None
Date: October 1, 1974
Creator: Wollenberg, H.A.
Object Type: Report
System: The UNT Digital Library
Accidental Radiogold (198Au) Liver Scan Overdose With Fatal Outcome (open access)

Accidental Radiogold (198Au) Liver Scan Overdose With Fatal Outcome

This report addresses the use of radioisotopes for scanning, which has added significantly to the clinician's ability to detect and interpret disease manifestations.
Date: October 31, 1969
Creator: Baron, J.M.; Yachnin, S.; Polcyn, R.; Fitch, F.W. & Sturner, W.G.
Object Type: Report
System: The UNT Digital Library
Sol-Gel Processes for Isotopic Heat Sources. (open access)

Sol-Gel Processes for Isotopic Heat Sources.

None
Date: October 31, 1969
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Recording Equipment for Internal Friction Measurements (open access)

Recording Equipment for Internal Friction Measurements

An apparatus was developed for recording internal friction data in such a manner as to circumvent many of the laborious and time-consuming observations and calculations usually associated with these measurements. An optical lever is used and the passage of the beam across the scale is detected by photoconductive cells. The cells are strategically located so that, when their signals are fed through a multichannel switching circuit to the pens of an operation recorder, a plot of the logarithm of the vibrational amplitude versus the number of cycles is recorded on the chart. From the definitmon of the logarithmic decrement, ( delta ), it can be shown that the slope of this curve is - delta . The apparatus is inexpensive and requires a minimum of maintenance. It has been used for accurate determinations of values of delta from below 0.0001 up to 0.3. (auth)
Date: October 31, 1961
Creator: Stephenson, R. L. & McCoy, H. E. Jr.
Object Type: Report
System: The UNT Digital Library
(Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio) (open access)

(Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio)

This report presents information concerning field procedures employed during the monitoring, well construction, well purging, sampling, and well logging at the Wright-Patterson Air Force Base. Activities were conducted in an effort to evaluate ground water contamination.
Date: October 1, 1991
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Sodium Chemistry, Fission Product Contamination. (open access)

Sodium Chemistry, Fission Product Contamination.

None
Date: October 31, 1969
Creator: Silberberg, M.; Guon, J. & Zwetzig, G.
Object Type: Report
System: The UNT Digital Library
Intermediate-depth geothermal temperature study. Gradient holes: 11-33 and 63-33, Soda Lake, NV (open access)

Intermediate-depth geothermal temperature study. Gradient holes: 11-33 and 63-33, Soda Lake, NV

During 1979, Chevron Resources Company drilled two 2000 ft holes near Soda Lake in the Nevada Carson Sink area to obtain subsurface data for inclusion in the US Department of Energy's Northern Basin and Range geothermal reservoir assessment program. Drilling information together with detailed lithologic, geophysical and temperature log data were compiled for each hole and is summarized in this report. Maximum stabilized temperatures of 297/sup 0/F and 367/sup 0/F were encountered at total depth in each of the holes, respectively.
Date: October 1, 1979
Creator: Hill, D.G.
Object Type: Report
System: The UNT Digital Library
Establishment of viscometer capability for geopressured fluids. Project 61024 final report, November 19, 1978-December 31, 1979 (open access)

Establishment of viscometer capability for geopressured fluids. Project 61024 final report, November 19, 1978-December 31, 1979

The feasibility of modifying the IGT capillary viscometer for the measurement of methane-saturated brines at 10,000 psi and 200/sup 0/C was evaluated. The viscometer was cleaned, modified, reassembled and pressure treated. The density cells were calibrated to a precision of approximately 7%. The viscosity of pure value was measured and the best value obtained was 6% below values reported in the literature. The operation of the viscometer was time-consuming and required meticulous cleaning between experiments. Some corrosion at the mercury surface interfered with the efficient operation of the timing device. Other problems were encountered due to gas bubbles trapped in the capillary flow path. Consequently, data on methane-saturated brine could not be obtained within the funding limitations of this program. It is concluded that further work on the existing viscometer would not be cost-effective.
Date: October 1, 1980
Creator: Rockar, E. & Randolph, P.
Object Type: Report
System: The UNT Digital Library
ORR Operations for Period April 1961 to April 1962 (open access)

ORR Operations for Period April 1961 to April 1962

A summary of the activities in the 4th operational year is presented for the ORR. On-stream time at 30 Mw was relatively steady with 75.4 and 83.7% representing the lowest and highest quarters. Modification of the ball-latch mechanism of the shim-rod-drives is in progress. The primary cooling system bypass control valve was modified and a d-c pony motor was added at the No. 3 primary pump. This addition was made to increase the reliability of adequate water flow for afterheat cooling. A study of coreboiling detection is being conducted. (J.R.D.)
Date: October 16, 1962
Creator: Binford, F.T.; Casto, W.R. & Colomb, A.L.
Object Type: Report
System: The UNT Digital Library
Two-photon physics (open access)

Two-photon physics

A new experimental frontier has recently been opened to the study of two photon processes. The first results of many aspects of these reactions are being presented at this conference. In contrast, the theoretical development of research ito two photon processes has a much longer history. This talk reviews the many different theoretical ideas which provide a detailed framework for our understanding of two photon processes.
Date: October 1, 1981
Creator: Bardeen, W.A.
Object Type: Article
System: The UNT Digital Library
Exploring novel silicon-containing polymers---From preceramic polymers to conducting polymers with nonlinear optical properties (open access)

Exploring novel silicon-containing polymers---From preceramic polymers to conducting polymers with nonlinear optical properties

Several new types of silicon-containing preceramic polymers, i.e., poly(diorganosilacetylene) and poly(diorganosilvinylene) have been synthesized with molecular weights from 10,000 to 120,000. These polymers could be thermally converted to SiC with a moderate to high char yields. Ready solubility and good processability made these types of polymers attractive in their applications to ceramics. The thermal polymerization of diethynyldiphenyl-silane, which was reported in 1968 to afford poly(diphenylsilyldiacetylene) via dehydrogenation, was reinvestigated. Spectroscopic studies showed that the polymer had a structure of polyacetylene type not diacetylene. Diphenyldiethynylgermane and a series of diorganodiethynylsilances were synthesized. These could be polymerized in the presence of MoCl{sub 5} or WCl{sub 6} to afford a soluble, violet material with Mw as high as 108,000. 100 refs., 56 figs., 16 tabs.
Date: October 7, 1991
Creator: Pang, Yi.
Object Type: Report
System: The UNT Digital Library
Final Report of Modeling of CWM Droplet Combustion (open access)

Final Report of Modeling of CWM Droplet Combustion

The objective of the present study was to develop a one-dimensional, unsteady state model for coal-water mixture droplet combustion, and to compare the characteristic times for the various processes, such as water vaporization, devolatilization and char oxidation with available experimental data. A water film surrounding a spherical coal particle is considered to undergo vaporization by heat transfer from the hot air. After the water vaporization is complete, devolatilization begins. This process is assumed to be kinetically controlled. Water vaporization and devolatilization processes are modeled by using a hybrid Eulerian-Lagrangian method to obtain the properties of the gas-phase and the condensed-phase. An explicit finite difference scheme is used to solve the Eulerian gas-phase equation where as a Runga-Kutta scheme is employed to solve the Lagrangian condensed-phase equations. The predicted characteristic times for water vaporization is in good agreement with values proposed in the literature. At the present time there is insufficient data to draw any conclusions on the model. Methods are proposed to refine the simple kinetic model which takes into account pore diffusion and mass transfer for devolatilization and char oxidation. 9 references, 12 figures.
Date: October 1, 1983
Creator: Pandalai, Krish; Aggarwal, Suresh & Sirignano, William
Object Type: Report
System: The UNT Digital Library
Joining of ceramics for high performance energy systems. Mid-term progress report, August 1, 1979-March 31, 1980 (open access)

Joining of ceramics for high performance energy systems. Mid-term progress report, August 1, 1979-March 31, 1980

The subject program is primarily an exploratory and demonstration study of the use of silicate glass-based adhesives for bonding silicon-base refractory ceramics (SiC, Si/sub 3/N/sub 4/). The projected application is 1250 to 2050/sup 0/F relaxing joint service in high-performance energy conversion systems. The five program tasks and their current status are as follows. Task 1 - Long-Term Joint Stability. Time-temperature-transformation studies of candidate glass adhesives, out to 2000 hours simulated service exposure, are half complete. Task 2 - Environmental and Service Effects on Joint Reliability. Start up delayed due to late delivery of candidate glass fillers and ceramic specimens. Task 3 - Viscoelastic Damping of Glass Bonded Ceramics. Promising results obtained over approximately the same range of glass viscosity required for joint relaxation function (10/sup 7.5/ to 10/sup 9.5/ poise). Work is 90% complete. Task 4 - Crack Arrest and Crack Diversion by Joints. No work started due to late arrival of materials. Task 5 - Improved Joining and Fabrication Methods. Significant work has been conducted in the area of refractory pre-glazing and the application and bonding of high-density candidate glass fillers (by both hand-artisan and slip-spray techniques). Work is half complete.
Date: October 6, 1980
Creator: Smeltzer, C E & Metcalfe, A G
Object Type: Report
System: The UNT Digital Library
Light Absorption and Scattering Mechanisms in Laser Fusion Plasmas (open access)

Light Absorption and Scattering Mechanisms in Laser Fusion Plasmas

The picture of laser light absorption and scattering which is emerging from theory and computer simulation studies of laser-plasma interactions is described. On the subject of absorption, we discuss theoretical and experimental evidence that resonance absorption in a steepened density profile is a dominant absorption mechanism. Recent work also indicates the presence of critical surface ripples, which we study using two and three dimensional computer simulations. Predictions of hot electron spectra due to resonance absorption are described, as are effects of plasma outflow. We then discuss two regimes where stimulated scattering may occur. Brillouin scattering is expected in the underdense target blow-off, for long laser pulses, and is limited by ion heating. Raman scattering in the background gas of a reactor target chamber is predicted to be at most a 10 percent effect for 1 ..mu..m lasers.
Date: October 4, 1977
Creator: Barnes, C.; Estabrook, K. G.; Kruer, W. L.; Langdon, A. B.; Lasinski, B. F.; Max, C. E. et al.
Object Type: Article
System: The UNT Digital Library
Potential for efficient frequency conversion at high average power using solid state nonlinear optical materials (open access)

Potential for efficient frequency conversion at high average power using solid state nonlinear optical materials

High-average-power frequency conversion using solid state nonlinear materials is discussed. Recent laboratory experience and new developments in design concepts show that current technology, a few tens of watts, may be extended by several orders of magnitude. For example, using KD*P, efficient doubling (>70%) of Nd:YAG at average powers approaching 100 KW is possible; and for doubling to the blue or ultraviolet regions, the average power may approach 1 MW. Configurations using segmented apertures permit essentially unlimited scaling of average power. High average power is achieved by configuring the nonlinear material as a set of thin plates with a large ratio of surface area to volume and by cooling the exposed surfaces with a flowing gas. The design and material fabrication of such a harmonic generator are well within current technology.
Date: October 28, 1985
Creator: Eimerl, D.
Object Type: Report
System: The UNT Digital Library
Discovery and History of $sup 252$Cf. (open access)

Discovery and History of $sup 252$Cf.

None
Date: October 31, 1969
Creator: Fields, P. R.
Object Type: Report
System: The UNT Digital Library
Diffusion of Slow Electrons in Gases (open access)

Diffusion of Slow Electrons in Gases

The properties of electrons in a gas and an external electric field, e.g., agitation velocity, free path, energy lost per collision, and collision cross sections, were determined for electrons of energy less than 2 ev in a large number of gases. The computations were made from previously measured values for Townsend's energy factor or the ratio of electron agitation energy to molecule thermal energy. Results are presented for hydrogen, nitrogen, carbon dioxide, methane, ethylene, cyclopropane, and argon. (D.L.C.)
Date: October 24, 1961
Creator: Forester, D. W. & Cochran, L. W.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Effect of fuel recycling on radioactivity and thermal power of high-level wastes (open access)

Effect of fuel recycling on radioactivity and thermal power of high-level wastes

The radioactivity and thermal power of high-level and plutonium-bearing wastes from the nuclear fuel cycle have been calculated for the years 1975 to 2005 using the rate of generation of such wastes projected for the Generic Environmental Statement on Mixed Oxide Fuel (NUREG-0002). Three modes of fuel recycle are considered: (1) no recycle, (2) uranium recycle, and (3) prompt uranium and plutonium recycle. These cases are compared with a respect to radioactivity and thermal power of the generated waste, the waste shipments, and the accumulated inventories at reactor sites, reprocessing facilities, and ultimate disposal sites.
Date: October 1, 1977
Creator: Wachter, J.W.
Object Type: Report
System: The UNT Digital Library
The interpretation of reflectometry measurements of plasma fluctuations (open access)

The interpretation of reflectometry measurements of plasma fluctuations

Wave reflections from density fluctuations with magnitudes and frequencies typical of drift waves have been investigated. Both drift waves and the reflected phase and amplitude depend on the density gradient scale length, and this common feature implies that both the angular deviation of a normally propagating wave and the phase change on reflection are of order unity. Thus the surface will always appear rough'' and amplitude variations will always be large. For smaller amplitude waves numerical solutions of the one dimensional full wave equation for the propagation near cutoff frequencies has been used to show how to interpret reflectometry measurements. For density perturbations with wavelengths near the density scale length, the external fluctuating phase can be simply interpreted in terms of a fluctuating density near the cutoff layer. However, the amplitude of the phase response falls substantially as the fluctuation wavelength, {Lambda}, approaches the free space wavelength of the reflected wave, {lambda}{sub o}, and the location of the maximum response moves out in front of the cutoff layer following the wave matching condition k{sub {Lambda}} = 2k {approx} 2{eta}(x)k{sub 0}. Similarly, correlation measurements of density fluctuations from probe waves of different wavelengths are shown to be limited to about four …
Date: October 1, 1991
Creator: Bretz, N.
Object Type: Report
System: The UNT Digital Library
Thermodynamic model for calorimetric and phase coexistence properties of coal derived fluids (open access)

Thermodynamic model for calorimetric and phase coexistence properties of coal derived fluids

On September 1, 1989 work was initiated on a project to extend the available vapor-liquid equilibrium (VLE) model for coal fluids to allow satisfactory predictions of excess enthalpies of coal liquids at high pressures. The available vapor liquid equilibrium model was developed with support from previous grant from DOE-PETC (Grant no. DE-FG22-89PC90541). The current project also involves measurement of some model compound VLE data and chromatographic characterization of coal liquids for distribution of heteroatoms. A computational thermodynamic model for VLE, excess enthalpies and heat capacities of coal derived liquids has been developed. The model uses the modified UNIFAC correlation for the liquid phase. Some unavailable UNIFAC interactions parameters have been regressed from experimental VLE and excess enthalpy data. The computations are carried out using the method of continuous thermodynamics. Mode is used to derive interesting conclusions on the effect of oxygen, nitrogen, and sulfur heteroatoms on the thermodynamic properties of coal liquids. When compared with limited experimental data available for coal liquids the model shows good agreement. Some progress has been made on binary VLE measurements and size exclusion chromatography of coal liquids.
Date: October 1, 1991
Creator: Kabadi, V. N.
Object Type: Report
System: The UNT Digital Library