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19,325 Matching Results
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A High-Temperature, Fluidized-Bed Process for Converting Uranium Dioxide to Uranium Monocarbide.
None
Date:
November 1968
Creator:
Holmes, John T.; Pavlik, John R.; Nelson, Paul A. & Graae, Johan E. A.
Object Type:
Report
System:
The UNT Digital Library
Anaerobic fermentation of simulated in-situ oil shale retort water
The feasibility of removing soluble organics from oil shale retort water by anaerobic digestion with methane production was experimentally investigated. The following conclusions were made. The retort water studied had to be pretreated to remove toxic and add deficient constituents before it could be successfully treated with the anaerobic fermentation process. Pretreatment included pH adjustment to 7, ammonia reduction, and nutrient addition. A digested sludge from a conventional municipal sewage treatment plant was successfully acclimated to the retort water studied. A major fraction of the organics in the retort water studied was stabilized by conversion to CH/sub 4/ and CO/sub 2/ using the anaerobic fermentation process. BOD/sub 5/ and COD removal efficiences were 76 to 80 percent. The effluent from anaerobic fermentation of the retort water studied (BOD/sub 5/ : 530 to 580 mg/l) may be suitable for treatment by conventional aerobic processes. The growth of the methane formers, which stabilize the organics, is nutrient limited in the retort water studied. The pretreatment of the retort water studied removed 49 percent of the BOD/sub 5/. This was probably due to the reduction in solubility of high molecular weight fatty acids at neutral pHs. A major component removed from the retort …
Date:
November 1, 1977
Creator:
Ossio, E. A.; Fox, J. P.; Thomas, J. F. & Poulson, R. E.
Object Type:
Article
System:
The UNT Digital Library
Nuclear chemistry research of high-energy nuclear reactions at Carnegie-Mellon University, 1961--1977. Summary report. [Summaries of research activities at Carnegie-Mellon University]
The activities and the results of research in the study of high energy nuclear reactions carried out at Carnegie Institute of Technology from 1957 to 1967 and at Carnegie-Mellon University from 1967 to 1977 are summarized. A complete list of all publications, doctoral dissertations, and reports resulting from the research of this project is also included. A major part of the report is a review of the research activities and results. The objective of the research of this project was the study of reactions initiated by projectiles of energy above about 100 MeV. The main effort was the investigation of simple nuclear reactions with the objective to deduce reaction mechanisms. These reactions were also used as probes to determine the nuclear structure of the target. In addition, a number of studies of spallation reactions were undertaken which included the determination of excitation functions and recoil properties. Recent research activities which have involved the study of pion induced reactions as well as reactions initiated by heavy ions is also discussed.
Date:
November 1, 1977
Creator:
Caretto, A. A., Jr.
Object Type:
Report
System:
The UNT Digital Library
Polysaccharides and bacterial plugging
Before any successful application of Microbial Enhanced Oil Recovery process can be realized, an understanding of the cells' transport and retentive mechanisms in porous media is needed. Cell transport differs from particle transport in their ability to produce polysaccharides, which are used by cells to adhere to surfaces. Cell injection experiments have been conducted using Leuconostoc cells to illustrate the importance of cellular polysaccharide production as a transport mechanism that hinders cell movement and plugs porous media. Kinetic studies of the Leuconostoc cells, carried out to further understand the plugging rates of porous media, have shown that the cells' growth rates are approximately equal when provided with monosaccharide (glucose and fructose) or sucrose. The only difference in cell metabolism is the production of dextran when sucrose is supplied as a carbon source. Experimentally it has also been shown that the cells' growth rate is weakly dependent upon the sucrose concentration in the media, and strongly dependent upon the concentration of yeast extract. The synthesis of cellular dextran has been found to lag behind cell generation, thus indicating that the cells need to reach maturity before they are capable of expressing the detransucrase enzyme and synthesizing insoluble dextran. Dextran yields were …
Date:
November 1, 1991
Creator:
Fogler, H. S.
Object Type:
Report
System:
The UNT Digital Library
Time-Dependent Two-Dimensional Radiation Hydrodynamics of Accreting Matter Onto Highly Magnetized Neutron Stars
We present for the first time, the self-consistent solution of the two-dimensional, time-dependent equations of radiation-hydrodynamics governing the accretion of matter onto the highly magnetized polar caps of luminous x-ray pulsars. The calculations show a structure in the accretion column very different from previous one-zone uniform models. We have included all the relevant magnetic field corrections to both the hydrodynamics and the radiative transport. We include a new theory for the diffusion and advection of both radiation energy density and photon number density. For initially uniformly accreting models with super-Eddington flows, we have uncovered evidence of strong radiation-driven outflowing optically thin radiation filled regions of the accretion column embedded in optically-thick inflowing plasma. The development of these photon bubbles'' have growth times on the order of a millisecond and show fluctuations on sub-millisecond timescales. The photon bubbles are likely to be a consequence of convective over-stability and may result in observable fluctuations in the emitted luminosity leading to luminosity dependent changes in the pulse profile. This may provide important new diagnostics for conditions in accreting x-ray pulsars. 13 refs., 18 figs.
Date:
November 24, 1989
Creator:
Klein, R.I. (California Univ., Los Angeles, CA (USA). Dept. of Astronomy Lawrence Livermore National Lab., CA (USA) California Univ., Los Angeles, CA (USA). Inst. of Geophysics and Planetary Physics) & Arons, J. (California Univ., Berkeley, CA (USA). Dept. of Astronomy California Univ., Los Angeles, CA (USA). Inst. of Geophysics and Planetary Physics CEA Centre d'Etudes Nucleaires de Saclay, 91 -
Object Type:
Article
System:
The UNT Digital Library
Zero Field Magnetic Properties of Gadolinium Terbium, and Samarium
The mutual inductance or apparent susceptibility due to the presence of the sample in a coaxial inductance coil was observed for Gd, Tb, and Sm in fields of a few gauss over the respective temperature ranges of 78 to 310 deg K, 78 to 235 deg K, and 4.2 to 150 deg K. A paramagnetic Curie point of 284.2 deg K was found for Gd. For Tb, a transition was found which occurred to within 1 deg of the predicted temperature of 220 deg K, and a second peak occurred at 229.4 deg K which is within 2 deg of the heat capacity peak. The 220 deg K peak exhibited hysteresis and time dependence. Extrapolation of Tb data to DELTA M = 0 yielded a Curie point of 235.6 deg K. No hysteresis was observed in the 14.8 deg K peak for Sm. (D.L.C.)
Date:
November 1, 1960
Creator:
Hill, E. D. & Spedding, F. H.
Object Type:
Report
System:
The UNT Digital Library
Advanced energy sources and conversion techniques. Volume 1. [35 papers]
This report addresses the advanced energy sources and conversion techniques.
Date:
November 1, 1958
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Eastern Gas Shales Program. Completion and stimulation of five New York State Energy Research and Development Authority Wells Allegany and Cattaraugus Counties, New York
In order to evaluate the potential of the Devonian Shales as a source of natural gas, DOE/METC in Morgantown, West Virginia, has undertaken the Eastern Gas Shale Program (EGSP); not only to characterize and identify the resource, but also to enhance and improve the productivity of wells completed in the shale. One of the methods used to achieve improved productivity is hydraulic fracturing and, more specifically, foam fracturing. The efforts by DOE/METC included completion and stimulation of five New York State Energy Research and Development Authority (NYSERDA) wells; located in western Allegany County and southwestern Cattaraugus County, New York. The five wells were drilled on high shcool and college properties during the months of June and July 1981. DOE/METC's contribution to the program funded the stimulation and completion of the wells. This work was done under the engineering and field supervision of Gruy Federal, Inc. as contractor to DOE. The completion work took place in the months of July and August 1981. This consisted of running a cement bond log in each well. All logs showed good bonding. This was followed by perforating the Marcellus Shale through the 4-1/2-inch casing. During the next phase, the formation was broken down with …
Date:
November 1, 1981
Creator:
Rdissi, A.
Object Type:
Report
System:
The UNT Digital Library
Mass and energy budgets of animals: Behavioral and ecological implications
The two major aims of our lab are as follows: First, to develop and field-test general mechanistic models that predict animal life history characteristics as influenced by climate and the physical, physiological behavioral characteristics of species. This involves: understanding how animal time and energy budgets are affected by climate and animal properties; predicting growth and reproductive potential from time and energy budgets; predicting mortality based on climate and time and energy budgets; and linking these individual based models to population dynamics. Second to conduct empirical studies of animal physiological ecology, particularly the effects of temperature on time and energy budgets. The physiological ecology of individual animals is the key link between the physical environment and population-level phenomena. We address the macroclimate to microclimate linkage on a broad spatial scale; address the links between individuals and population dynamics for lizard species; test the endotherm energetics and behavior model using beaver; address the spatial variation in climate and its effects on individual energetics, growth and reproduction; and address patchiness in the environment and constraints they may impose on individual energetics, growth and reproduction. These projects are described individually in the following section. 24 refs., 9 figs.
Date:
November 1, 1991
Creator:
Porter, W.P.
Object Type:
Report
System:
The UNT Digital Library
Research and Development of Metal Hydrides. Summary Report for October 1, 1958-September 30, 1960
A detailed study of the fundamental relations in the zirconium -- hydrogen system was made in order to clarify the many points of dispute and to evolve a complete picture describing all phases of this system. An engineering evaluation was made of means for utillzing the various high cross-section metal hydrides in shielding or control applications. These materials would combine the processes of thermalization and absorption. Consequently, they are of considerable interest for use in shielding or controlling epithermal reactors. (auth)
Date:
November 1, 1960
Creator:
Beck, R. L.
Object Type:
Report
System:
The UNT Digital Library
Automatic lead frame plating. Final report
None
Date:
November 1, 1975
Creator:
Jarboe, D.M.
Object Type:
Report
System:
The UNT Digital Library
Neutronics of a mixed-flow gas-core reactor
The study was made to investigate the neutronic feasibility of a mixed-flow gas-core reactor. Three reactor concepts were studied: four- and seven-cell radial reactors and a seven-cell scallop reactor. The reactors were fueled with UF/sub 6/ (either U-233 or U-235) and various parameters were varied. A four-cell reactor is not practical nor is the U-235 fueled seven-cell radial reactor; however, the 7-cell U-233 radial and scallop reactors can satisfy all design criteria. The mixed flow gas core reactor is a very attractive reactor concept and warrants further investigation.
Date:
November 1, 1977
Creator:
Soran, P. D. & Hansen, G. E.
Object Type:
Report
System:
The UNT Digital Library
Evaluation of Hydrocarbon Diluents for the Purex Process
Forty-nine hydrocarbon products were evaluated in the laboratory in a search for a highly stable diluent for the organic extractant used in a radiochemical separations plant. The formation of zirconium ligands during chemical and radiolytic degradation increased with boiling point for isoparaffinic producte but was approximately constant for n-parafiins. Of those materials that met the local flash point specification, the n-parafiins were superior. (auth)
Date:
November 1, 1961
Creator:
Dennis, B. P. & West, D. L.
Object Type:
Report
System:
The UNT Digital Library
Theoretical modeling and experimental characterization of planar defects in Y sub 2 Ba sub 4 Cu sub 6+x O sub 14+x
Crystallographic defects and phase transformations in the system Y{sub 2}Ba{sub 4}Cu{sub 6 + x}O{sub 14 + x}(0{le}{times}{le}4) are investigated by high resolution transmission electron microscopy (TEM) and static lattice, three dimensional Monte Carlo computer simulations. High resolution images of partially transformed (x = 2 to x = 1) material reveal a prevalence of CuO planar defects (stacking faults) associated with the transformation and an absence of disturbance to the perovskite Ba-Y-Ba blocks. An atomic mechanism involving the intercalculation and removal of extra CuO planes by partial dislocation climb, and requiring only a-b plane diffusion, is developed for the formation of such planar defects during changes in the layered YBaCuO crystal structure. Monte Carlo simulations based on the proposed transformation mechanism accurately reproduce the observed defects and known equilibrium structures. 24 refs., 4 figs.
Date:
November 1, 1990
Creator:
Burmester, C. P.; Fendorf, M.; Gronsky, R. & Wille, L. T.
Object Type:
Article
System:
The UNT Digital Library
Framework for control system development
Control systems being developed for the present generation of accelerators will need to adapt to changing machine and operating state conditions. Such systems must also be capable of evolving over the life of the accelerator operation. In this paper we present a framework for the development of adaptive control systems.
Date:
November 1, 1991
Creator:
Cork, C. & Nishimura, Hiroshi.
Object Type:
Article
System:
The UNT Digital Library
AN ANALYSIS TO DETERMINE THE PERCENTAGE OF HELIUM BYPASSING THE CORE DUE TO THE REFLECTOR SEALING SYSTEM DURING NORMAL OPERATION OF THE HTGR
The percentage of helium which will bypass the core if the reflector system shown is used is predicted. It is estimated that nominally about 0.1 to 0.2% of the total flow will bypass the core, which is not considered excessive. The most difficult parameter to determine was Z, the gap between the sealing surfaces. The method used to predict Z is presented. The effect of bowing due to a temperature gradient across the seals is discussed. (auth)
Date:
November 15, 1961
Creator:
Nimtz, F.B.
Object Type:
Report
System:
The UNT Digital Library
Motion of a Loosely Fitting Piston in a Closed End Cylinder Containing a Perfect Gas
The equations of motion are derived for a piston in a closed end cylinder containing a compressible perfect gas. These equations include the possibility of an arbitrary motion imposed on the cylinder. In the analysis, it is assumed that there is a clearance between the piston and the cylinder which is sufficiently small so that the flow in the gap is controlled by viscous forces.
Date:
November 1, 1975
Creator:
Stone, G. W.; Reis, G. E. & Kaestner, P. C.
Object Type:
Report
System:
The UNT Digital Library
Outdoor sources of indoor air pollution
Conservation measures that seal a building, like storm window installation, can significantly reduce its energy requirements. These measures also protect its occupants from air pollutants having outdoor sources but amplify any harmful effects of those generated indoors. Using these Fourier series techniques and an approximation of outdoor pollution peaks by step functions, we obtained the following results: the average daily concentration indoors is the same as outdoors for any pollutant with no indoor sinks if inside and outside air are assumed uniform (that is, well mixed). However, lowering a building's air exchange rate 4-fold will still protect its occupants from outdoor pollution sources, but only if the outdoor peak or variation above its average is much greater than its average, and the peak is short-lived.
Date:
November 1, 1977
Creator:
Silberstein, S.
Object Type:
Report
System:
The UNT Digital Library
Physical-Chemical Treatment of Tar Sand Processing Wastewater: [Final Report, Tasks 3-5]
The dewatering properties of residuals generated by flotation/foam fractionation treatment of TS-1S wastewater were evaluated. The leachate potential was studied for both chemical coagulation and flotation/foam fractionation sludges. A preliminary economic analysis was made comparing selected sludge disposal options and summarizing previously reported economic analysis of the chemical treatment alternatives.
Date:
November 1983
Creator:
King, Paul H.
Object Type:
Report
System:
The UNT Digital Library
Arsenic Removal From Gaseous Streams
Uranium feed materials, depending on the production process, have been found to contain arsenic (As) as a contaminant. Analyses show the As to be present as As pentafluoride (AsF{sub 5}) and/or hexafluoroarsenic acid (HAsF{sub 6}) and enter the enrichment cycle through contaminated hydrogen fluoride (HF). Problems related to corrosion of cylinder valves and plugging of feed lines and valves have been attributed to the As. Techniques to separate AsF{sub 5} from uranium hexafluoride (UF{sub 6}) using sodium fluoride (NaF) as a trapping media were successful and will be discussed. Procedures to significantly reduce (up to 97%) the level of As in HF will also be reported. 5 figs., 9 tabs.
Date:
November 22, 1989
Creator:
Russell, R. G. & Otey, M. G.
Object Type:
Report
System:
The UNT Digital Library
Estimate of earth media shear strength at the Nevada Test Site
A method is presented of estimating the effective shear strength of the fractured rock that surrounds a nuclear detonation. To do this, we measure the cavity radii from previous detonations. We also use numerical computer codes to model the explosion phenomenology and develop the functional relationship between the normalized cavity displacement and the normalized shear strength of the rock. In this sense, the computer codes serve as replica models that are dimensionally analyzed to interpret the field experience. We separate the effects of gravity and overburden pressure from the effects of the material properties and give scaling laws for each. We have analyzed approximately 300 nuclear detonations at the Nevada Test Site (NTS) and have found that the most frequent shear strengths are between 0.020 and 0.060 kbars. They are also essentially independent of the depth-of-burial ranges considered. We obtained good agreement between predicted shear strengths and those measured from core samples for different areas at the Nevada Test Site.
Date:
November 3, 1977
Creator:
Terhune, R. W. & Glenn, H. D.
Object Type:
Report
System:
The UNT Digital Library
The geometry of the Virasoro group for physicists
Diff(S/sup 1/), the group of reparametrizations of the circle, is known as the Virasoro group in string theory. Reparametrizations keeping fixed a point of the circle form the quotient space Diff(S/sup 1/)S/sup 1/. The geometry of this space is relevant for string theory and string field theory. We describe this space as an infinite dimensional complex manifold with a Kaehler metric and compute ist Riemann tensor and its Ricci tensor. 7 refs
Date:
November 1, 1987
Creator:
Zumino, B.
Object Type:
Article
System:
The UNT Digital Library
AN INVESTIGATION OF THE HIGH-TEMPERATURE PROPERTIES OF THE AISI TYPE 502 STEEL
None
Date:
November 28, 1961
Creator:
Martin, W. R. & McCoy Jr., H. E.
Object Type:
Report
System:
The UNT Digital Library
A Summary of Shielding Constants for Concrete
The present knowledge of the shielding constants of concrete is summarized. The densities, elemental compositions, and mixes, where available, are given for a wide range of concretes. From these data, various constants useful for shielding calculations were computed. These constants include the removal cross sections, total cross sections, average thermal neutron absorption cross sections, thermal neutron diffusion coefficients, reciprocal thermal neutron diffusion lengths, total gamma-ray linear attenuation coefficients, gamma-ray energy absorption linear attenuation coefficients, the effective atomic numbers for the determination of buildup factors, and the capture gamma-ray spectra. Experimental results are included where available. (auth)
Date:
November 1, 1961
Creator:
Walker, R.L. & Grotenhuis, M.
Object Type:
Report
System:
The UNT Digital Library