Degree Discipline

Degree Level

Removal of trichloroethylene contamination from the subsurface: A comparative evaluation of different remediation strategies by means of numerical simulation (open access)

Removal of trichloroethylene contamination from the subsurface: A comparative evaluation of different remediation strategies by means of numerical simulation

Volatile organic compounds such as petroleum hydrocarbons and halogenated hydrocarbon solvents are common contaminants of the subsurface environment. Although immiscible with water, many of these organics have large enough aqueous phase solubilities to significantly degrade the quality of groundwater with which they come in contact. In addition, many of these substances exhibit high vapor pressures, causing them to partition strongly into the gas phase in their surroundings. Because of these properties, a volatile organic compound (VOC), once introduced into the subsurface may be transported as a solute, a vapor, or as a constituent in a non- aqueous phase liquid (NAPL). This implies that at some sits, an adequate description of the migration of these contaminants in the subsurface would necessarily involve three phases, -- gas, aqueous and NAPL. For example, to design an effective aquifer remediation scheme for a site where NAPL is present, it would be wrong to focus solely on the aqueous phase while ignoring either the gas phase or the NAPL phase. In the present work, we use a simulator developed by Falta et al. (1990a), known as STMVOC,'' which models true three-phase flow in which NAPL, gas and aqueous phases can move in response to pressure, …
Date: December 1, 1990
Creator: Adenekan, A.E.; Pruess, K. & Falta, R.W.
Object Type: Report
System: The UNT Digital Library
Linear magnetic fusion: summary of Seattle workshop (open access)

Linear magnetic fusion: summary of Seattle workshop

The linear-geometry magnetic confinement concept is among the oldest used in the study of high-temperature plasmas. However, it has generally been discounted as a suitable approach for demonstrating controlled thermonuclear fusion because rapid losses from the plasma column ends necessitate very long devices. Further, the losses and how to overcome them have not yet received parametric experimental study, nor do facilities exist with which such definitive experiments could be performed. Nonetheless, the important positive attribute, simplicity, together with the appearance of several ideas for reducing end losses have provided motivation for continued research on linear magnetic fusion (LMF). These motivations led to the LMF workshop, held in Seattle, March 9--11, 1977, which explored the potential of LMF as an alternate approach to fusion. A broad range of LMF aspects were addressed, including radial and axial losses, stability and equilibrium, heating, technology, and reactor considerations. The conclusions drawn at the workshop are summarized.
Date: December 1, 1977
Creator: unknown
Object Type: Article
System: The UNT Digital Library
REMOTELY CONTROLLED SHEARING OF PIPE AND STRUCTURAL MEMBERS (open access)

REMOTELY CONTROLLED SHEARING OF PIPE AND STRUCTURAL MEMBERS

A shearing tool was developed for remotely controlled severing of pipes or structural members. The shear is rotated about its axis in a wrist motion by the pumped hydraulic fluid that also powers the shear blade. It can be used in a stationary mounting or suspended from a crane. A C-shaped support for the shear was designed to pass through a small top opening of a shielded cell. The controls for manipulating the shear pass through or along the Cframe. The shear jaw opens to 5 in. in height and 7 in. in width, and the total weight of the tool is only 575 lb. It was used to cut metal sections 4 3/4 in. thick and 4-in. sched.-40 stainless steel pipe. (auth)
Date: December 28, 1961
Creator: Abbatiello, A. A.
Object Type: Report
System: The UNT Digital Library
Chemicals identified in human biological media: a data base. Third annual report, October 1981 (open access)

Chemicals identified in human biological media: a data base. Third annual report, October 1981

Data from almost 1600 of the 3800 body-burden documents collected to date have been entered in the data base as of October 1981. The emphasis on including recent literature and significant research documents has resulted in a chronological mix of articles from 1974 to the present. When body-burden articles are identified, data are extracted and entered in the data base by chemical and tissue/body fluid. Each data entry comprises a single record (or line entry) and is assigned a record number. If a particular document deals with more than one chemical and/or tissue, there will be multiple records for that document. For example, a study of 5 chemicals in each of 3 tissues has 15 different records (or 15 line entries) in the data base with 15 record numbers. Record numbers are assigned consecutively throughout the entire data base and appear in the upper left corner of the first column for each record.
Date: December 1, 1981
Creator: Cone, M.V.; Baldauf, M.F. & Martin, F.M. (comps.)
Object Type: Report
System: The UNT Digital Library
Results of the radiological survey at 15 John Street, Lodi, New Jersey (LJ087) (open access)

Results of the radiological survey at 15 John Street, Lodi, New Jersey (LJ087)

Maywood Chemical Works (MCW) of Maywood, New Jersey, generated process wastes and residues associated with the production and refining of thorium and thorium compounds from monazite ores from 1916 to 1956. MCW supplied rare earth metals and thorium compounds to the Atomic Energy Commission and various other government agencies from the late 1940s to the mid-1950s. Area residents used the sandlike waste from this thorium extraction process mixed with tea and cocoa leaves as mulch in their yards. Some of these contaminated wastes were also eroded from the site into Lodi Brook. At the request of the US Department of Energy (DOE), a group from Oak Ridge National Laboratory conducts investigative radiological surveys of properties in the vicinity of MCW to determine whether a property is contaminated with radioactive residues, principally {sup 232}Th, derived from the MCW site. The survey typically includes direct measurement of gamma radiation levels and soil sampling for radionuclide analyses. The survey of this site, 15 John Street, Lodi, New Jersey (LJ087), was conducted during 1988. 5 refs., 3 figs., 3 tabs.
Date: December 1, 1989
Creator: Foley, R.D. & Floyd, L.M.
Object Type: Report
System: The UNT Digital Library
WEATHER MODIFICATION (open access)

WEATHER MODIFICATION

It is suggested that applying heat directly to a rain cloud, or to a ndoist air mass with rain potential, may alter the natural precipitation in a given geographical region. The immediate effect of the heat is to increase the buoyancy of the cloud or air parcel. The result, which depends on a number of interrelated factors may be either to cause precipitation where it would not naturally occur, or to suppress precipitation where it would naturally occur. Several possible applications are suggested. Since the heat supplied is supplemented by the latent heat resulting from condensation in the moist air mass, the results may more than justify the cost. However, substantial amounts of heat are involved. The heat can be supplied from fossil fuels, nuclear reactions, or a combination of both; but the logistics favor the use of large nuclear reactors wherever safety criteria can be met. Not only the efficiency and economics of the process, but also its feasibility, can be finally decided only on the basis of information that is not now available. (auth)
Date: December 1, 1961
Creator: Rodin, M.B. & Hess, D.C.
Object Type: Report
System: The UNT Digital Library
Silicon halide-alkali metal flames as a source of solar grade silicon. Second quarterly report, September 1--November 30, 1977 (open access)

Silicon halide-alkali metal flames as a source of solar grade silicon. Second quarterly report, September 1--November 30, 1977

The experimental effort on this program has concentrated thus far on Na/SiCl/sub 4/ and K/SiCl/sub 4/ opposed jet diffusion flames in an evacuated reaction vessel; both reactants are supplied as vapors. The flames are self-igniting, fast burning and intensely chemiluminescent. Solid reaction products have been collected, separated by simple washing, and some preliminary analyses performed which indicate that the concentrations of most impurities in the reagents are reduced during the course of the Si formation process. The chemiluminescence is being characterized spectroscopically. The products of reaction are all solids and appear as a mixture of brown (amorphous Si) and white (KCl) powders. Microscopic examination of the unwashed products reveals what seem to be agglomerates of Si particles with less than 1 ..mu..m diam. Washing with slightly acidic water easily removes the KCl. A tubular reactor for the preparation of larger quantities of products and possibly their separation via differential deposition is now being built. Provision is also being made for the addition of hot H/sub 2//Ar diluents and variable flow rates and pressures in this reactor.
Date: December 1, 1977
Creator: Miller, W.J.
Object Type: Report
System: The UNT Digital Library
Cosmology and the weak interaction (open access)

Cosmology and the weak interaction

The weak interaction plays a critical role in modern Big Bang cosmology. This review will emphasize two of its most publicized cosmological connections: Big Bang nucleosynthesis and Dark Matter. The first of these is connected to the cosmological prediction of Neutrino Flavours, N{sub {nu}} {approximately} 3 which is now being confirmed at SLC and LEP. The second is interrelated to the whole problem of galaxy and structure formation in the universe. This review will demonstrate the role of the weak interaction both for dark matter candidates and for the problem of generating seeds to form structure. 87 refs., 3 figs., 5 tabs.
Date: December 1, 1989
Creator: Schramm, D. N.
Object Type: Article
System: The UNT Digital Library
Unusual initial and final state effects in quantum chromodynamics (open access)

Unusual initial and final state effects in quantum chromodynamics

We have constructed a number of fundamental tests which can be used to probe discrete symmetries, and their possible violations, in the required new physics'' beyond the standard model. On-going experiments with unpolarized e{sup {minus}}e{sup +} collisions contain many events for the production-decay sequence e{sup {minus}}e{sup +} {yields} Z{degrees}, {gamma}* {yields} {tau}{sup {minus}}{tau}{sup +} {yields} (A{sup {minus}X}) (B{sup +}X). From the beam referenced spin-correlation function for this sequence, the photon and Z{degrees} boson couplings of the tau lepton can be completely measured. There are four distinct tests for CP/T violation in Z{degrees} {yields} {tau}{sup {minus}}{tau}{sup +}, and in {gamma}* {yields} {tau}{sup {minus}}{tau}{sup +}. The Lorentz structure of the associated helicity amplitudes is very simple. In other research programs, we are (1) continuing to investigate our proposal that partons be identified with nearly degenerate, coherent quark-gluon jet'' states, and are (2) investigating the novel consequences of q-analogue quantization of quantum fields, and of a completeness relation for the q-analogue coherent states.
Date: December 1, 1991
Creator: Nelson, C.A.
Object Type: Report
System: The UNT Digital Library
Continuous Czochralski growth. Silicon sheet growth development of the large area silicon sheet task of the Low Cost Silicon Solar Array Project. First quarterly progress report, October--December 1977 (open access)

Continuous Czochralski growth. Silicon sheet growth development of the large area silicon sheet task of the Low Cost Silicon Solar Array Project. First quarterly progress report, October--December 1977

The development of equipment and processes to produce single crystal solar silicon by a continuous Czochralski method was studied. ''Continuous'' is defined as the ability to produce 100 kilograms of crystal from only one melt container. The equipment to be used is a Hamco CG2000 Production Crystal Grower. Certain modifications will be made to the grower to enable periodic replenishment of silicon into the crucible and removal of grown crystals. The crystal grower was constructed and installed in a separate room designated and prepared for the project. It was adapted with a modified throat, a vacuum-tight isolation valve, an enlarged pull chamber to hold a supply of poly material, and a modified automatic diameter control (ADC) optical system. It was fully tested and made ready for trial runs. Designs are under way for other modifications to the equipment, including a recharge system, a polysilicon attachment device, and a modified bead-chain pull mechanism capable of pulling and simultaneously weighing a 30 to 40 Kg growing crystal. An economic model was developed for batch CZ as a base-line reference, and for two methods of continuous CZ. Preliminary analysis indicates a cost (value added by crystal growth) of approximately $13 to $17 per …
Date: December 31, 1977
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Hydrogenation of CO and CO/sub 2/ on clean rhodium and iron foils. Correlations of reactivities and surface compositions (open access)

Hydrogenation of CO and CO/sub 2/ on clean rhodium and iron foils. Correlations of reactivities and surface compositions

An experimental arrangement consisting of an ultrahigh vacuum bell jar equipped with an internal sample isolation cell was used to investigate the hydrogenation of CO over Fe and Rh surfaces. This apparatus permitted both UHV surface characterization (Auger electron spectroscopy, low-energy electron diffraction) and high pressure (1-20 atm) catalytic reactions to be carried out. Small surface area (approximately 1 cm/sup 2/) metal samples, both single crystals and polycrystalline foils, were used to catalyze the H/sub 2//CO reaction at high pressures (1-6 atm). Reaction products were monitored with a gas chromatograph equipped with a flame ionization detector. The surface compositions of the metal samples were determined before and after the reaction and the results correlated with the observed product distributions and reaction rates. In addition, the influence of various surface additives (carbon, oxygen, potassium) was also investigated. Iron was the more reactive of the two metals studied and was found to produce C/sub 1/-C/sub 5/ straight chain hydrocarbons but it poisoned rapidly. The catalytically active surface of both metals was covered with a carbonaceous monolayer. The carbonaceous monolayer was stable on the rhodium surface and produced C/sub 1/-C/sub 4/ hydrocarbons at a steady rate even after several hours of reaction. The …
Date: December 16, 1977
Creator: Dwyer, D.; Yoshida, K. & Somorjai, G.A.
Object Type: Article
System: The UNT Digital Library
Economic impact of using nonmetallic materials in low to intermediate temperature geothermal well construction (open access)

Economic impact of using nonmetallic materials in low to intermediate temperature geothermal well construction

Four appendices are included. The first covers applications of low-temperature geothermal energy including industrial processes, agricultural and related processes, district heating and cooling, and miscellaneous. The second discusses hydrogeologic factors affecting the design and construction of low-temperature geothermal wells: water quality, withdrawal rate, water depth, water temperature, basic well designs, and hydrogeologic provinces. In the third appendix, properties of metallic and nonmetallic materials are described, including: specific gravity, mechanical strength properties, resistance to physical and biological attack, thermal properties of nonmetallics, fluid flow characteristics, corrosion resistance, scaling resistance, weathering resistance of nonmetallics, and hydrolysis resistance of nonmetallics. Finally, special considerations in the design and construction of low-temperature geothermal wells using nonmetallics materials are covered. These include; drilling methods, joining methods, methods of casing and screen installation, well cementing, and well development. (MHR)
Date: December 1, 1979
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Ecological Studies Related to Construction of the Defense Waste Processing Facility on the Savannah River Site (open access)

Ecological Studies Related to Construction of the Defense Waste Processing Facility on the Savannah River Site

The Savannah River Ecology Laboratory has completed 10 years of ecological studies related to the construction of the Defense Waste Processing Facility (DWPF) on the Savannah River Site. This progress report examines water quality studies on streams peripheral to the DWPF construction site and examines the effectiveness of refuge ponds'' in ameliorating the effects of construction on local amphibians. Individual papers on these topics are indexed separately. 93 refs., 15 figs., 15 tabs. (MHB)
Date: December 1, 1988
Creator: Scott, David E.; Pechmann, Joesph H. K.; Knox, John N.; Estes, Ruth A.; McGregor, JoAnne H. & Bailey, K. (ed.)
Object Type: Report
System: The UNT Digital Library
Mechanical deflection analysis of diamond-turned reflective optics (open access)

Mechanical deflection analysis of diamond-turned reflective optics

An analytical technique has been developed that predicts the amount of warpage that metal reflective mirrors sustain due to various support and load conditions. The laser fusion project being conducted at LASL requires that metal reflective optics be fabricated by diamond turning. The diamond-turning process imposes some unusual loading conditions which result in mirror warpage. The finite-element method is used to compute mirror surface displacements resulting from these support and load conditions. Surface warpage is then determined by a best-fit comparison of these data to the desired surface contour. The technique is not limited to diamond turning, but can be used to predict warpage from a variety of loading conditions placed on the mirrors.
Date: December 1, 1977
Creator: Stoneking, J. E. & Gerth, H. L.
Object Type: Report
System: The UNT Digital Library
TITANIUM PUMP LOOP FOR AQUEOUS SOLUTIONS AT HIGH TEMPERATURES (open access)

TITANIUM PUMP LOOP FOR AQUEOUS SOLUTIONS AT HIGH TEMPERATURES

A titanium pump loop, designed to circulate aqueous solutions at temperatures and pressures up to 370 deg C and 3000 psia, was constructed. It is to be used to study the chemical stability of uranyl sulfate fuel solutions of interest to the Fluid Fuels Reactor Program. The total loop voluime was minimized so that about 2 liters uf solution was sufficient for loop operation. The equipment includes a sampling system to remove solution samples from the loop while operating at elevated temperature and pressure; a hydroclone to separate and remove any solids and/or heavyphase material formed; and provisions for installation of corrosion test specimens in the main loop stream. All equipment performed satisfactorily at design conditions in tests with water. (auth)
Date: December 13, 1961
Creator: Baker, J.M. & Bolt, S.E.
Object Type: Report
System: The UNT Digital Library
Microwave measurement test results of circular waveguide components for electron cyclotron resonant heating (ECRH) of the Tandem Mirror Experiment-Upgrade (TMX-U) (open access)

Microwave measurement test results of circular waveguide components for electron cyclotron resonant heating (ECRH) of the Tandem Mirror Experiment-Upgrade (TMX-U)

Development of high-power components for electron cyclotron resonant heating (ECRH) applications requires extensive testing. In this paper we describe the high-power testing of various circular waveguide components designed for application on the Tandem Mirror Experiment-Upgrade (TMX-U). These include a 2.5-in. vacuum valve, polarizing reflectors, directional couplers, mode converters, and flexible waveguides. All of these components were tested to 200 kW power level with 40-ms pulses. Cold tests were used to determine field distribution. The techniques used in these tests are illustrated. The new high-power test facility at Lawrence Livermore National Laboratory (LLNL) is described and test procedures are discussed. We discuss the following test results: efficiency at high power of mode converters, comparison of high power vs low power for waveguide components, and full power tests of the waveguide system. We also explain the reasons behind selection of these systems for use on TMX-U.
Date: December 1, 1983
Creator: Williams, C.W.; Rubert, R.R.; Coffield, F.E.; Felker, B.; Stallard, B.W. & Taska, J.
Object Type: Article
System: The UNT Digital Library
Sandia Laboratories technical capabilities: computation systems (open access)

Sandia Laboratories technical capabilities: computation systems

This report characterizes the computation systems capabilities at Sandia Laboratories. Selected applications of these capabilities are presented to illustrate the extent to which they can be applied in research and development programs. 9 figures.
Date: December 1, 1977
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Nuclear waste-form risk assessment for US Defense waste at Savannah River Plant. Annual report FY 1981 (open access)

Nuclear waste-form risk assessment for US Defense waste at Savannah River Plant. Annual report FY 1981

Savannah River Plant has been supporting the Lawrence Livermore National Laboratory in its present effort to perform risk assessments of alternative waste forms for defense waste. This effort relates to choosing a suitable combination of solid form and geologic medium on the basis of risk of exposure to future generations; therefore, the focus is on post-closure considerations of deep geologic repositories. The waste forms being investigated include borosilicate glass, SYNROC, and others. Geologic media under consideration are bedded salt, basalt, and tuff. The results of our work during FY 1981 are presented in this, our second annual report. The two complementary tasks that comprise our program, analysis of waste-form dissolution and risk assessment, are described.
Date: December 1, 1981
Creator: Cheung, H.; Edwards, L. L.; Harvey, T. F.; Jackson, D. D. & Revelli, M. A.
Object Type: Report
System: The UNT Digital Library
Preferred methods of analysis for chemical tracers in moderate- and high-temperature geothermal environments (open access)

Preferred methods of analysis for chemical tracers in moderate- and high-temperature geothermal environments

This report describes the sampling and analytical techniques used for tracer analysis in the Raft River and East Mesa field tests. The collection procedures and sample preservation techniques, analytical methods and possible sources of contamination or error are discussed in detail. 6 refs.
Date: December 1, 1984
Creator: Kroneman, R.L.; Yorgason, K.R. & Moore, J.N.
Object Type: Report
System: The UNT Digital Library
Design Data and Safety Features of Commercial Nuclear Power Plants. Vol. 2. Docket No. 50-296 Through 50-395 (open access)

Design Data and Safety Features of Commercial Nuclear Power Plants. Vol. 2. Docket No. 50-296 Through 50-395

None
Date: December 31, 1972
Creator: Heddleson, F. A.
Object Type: Report
System: The UNT Digital Library
ELECTROLYTIC DISSOLUTION OF NUCLEAR FUELS. PART I. ZIRCONIUM IN HCl- METHANOL (open access)

ELECTROLYTIC DISSOLUTION OF NUCLEAR FUELS. PART I. ZIRCONIUM IN HCl- METHANOL

The electrolytic dissolution of zirconium in HCl-methanol was studied as a function of potential, solution composition, and temperature. The dissolution is characterized by two regions. At high potentials the zirconium is electropolished and complete dissolution is achieved. At low potentials the current is an exponential function of the potential (Tafel behavior). In this region a small amount of finely divided alpha -zirconium which is insoluble in HCl-methanol separates from the bulk metal. The energy of activation for the corrosion reaction (0.0 volt) is 16.5 kcal/mole; in the electropolishing region (1.0 volt) the activation energy is 7.7 kcal/mole. A broad solvent capability for metallic reactor fuels is offered by the HCl-methanol medium since, in addition to zirconium, stainless steel is also dissolved electrolytically while uranium and aluminum dissolve chemically. Other process implications are discussed. (auth)
Date: December 29, 1961
Creator: Aylward, J. R.; Whitener, E. M. & Hahn, H. T.
Object Type: Report
System: The UNT Digital Library
Water chemistry and phytoplankton field and laboratory procedures (open access)

Water chemistry and phytoplankton field and laboratory procedures

The purpose of this manual is to serve as a guide for persons using these techniques in water quality studies and as a written record of the methods used in this laboratory at this time. It is anticipated that the manual will be updated frequently as new methods are added and the present ones are further refined. The present methods are all used routinely and have been in regular use for a year or longer. This manual is specifically written as a guide for the collection and analysis of lake water samples from the Laurentian Great Lakes. However, all of the analytical methods are easily adapted for laboratory culture or small lake studies. The descriptions contained in this manual are designed primarily as users guides oriented to the equipment available at the Great Lakes Research Division, and as most of the methods are taken from the literature, the reader is referred to the original articles for a more detailed discussion of the methods.
Date: December 1, 1979
Creator: Davis, C.O. & Simmons, M.S. (eds.)
Object Type: Report
System: The UNT Digital Library
Characterizing source regions with signal subspace methods: Theory and computational methods (open access)

Characterizing source regions with signal subspace methods: Theory and computational methods

A mathematical approach is developed for empirically characterizing a given source region using waveforms from a collection of calibration events. A region is considered to be adequately characterized if the waveforms from any event in the source region can be represented as a linear combination of calibration event waveforms. The purpose of such characterizations is to build waveform recognizers'' for specific regions for precision location applications, and to provide a means of separating superimposed waveforms from multiple events in different source regions. The particular form of characterization used is insensitive to variations in the source time function and to anything but changes from the normal range of source mechanisms encountered in the source region. The standard waveform correlation coefficient used to estimate event clustering is generalized to estimate separation between single events and event clusters, and between two clusters of events. The generalized correlation coefficient is insensitive to variations in source time function and, to some extent, mechanism. The statistics of waveform correlation coefficients are developed, and show that conventional estimates made from single station data are often developed for network or array data removes the ambiguity. 23 refs., 4 figs.
Date: December 1, 1989
Creator: Harris, D. B.
Object Type: Report
System: The UNT Digital Library
RADIATION CREEP (open access)

RADIATION CREEP

Several theories of metal creep and radiation damage are studied, in order to determine whether creep rates under various conditions of irradiation can be predicted theoretically. It is found that if the creep is of the recovery type, and if the diffusion coefficient for radiationinduced vacancies is large enough, creep rates may be increased within a limited temperature range. Otherwise, radiation has no effect on creep rates. (T.F.H.)
Date: December 1, 1957
Creator: Gregory, D.P.
Object Type: Report
System: The UNT Digital Library