Resource Type

Clay mineralogy and depositional history of the Frio Formation in two geopressured wells, Brazoria County, Texas (open access)

Clay mineralogy and depositional history of the Frio Formation in two geopressured wells, Brazoria County, Texas

Twenty-three shale samples ranging in depth from 5194 ft to 13,246 ft from Gulf Oil Corporation No. 2 Texas State Lease 53034 well and 33 shale samples ranging in depth from 2185 ft to 15,592 ft from General Crude Oil Company/Department of Energy No. 1 Pleasant Bayou well were examined by x-ray techniques to determine the mineralogy of the geopressured zone in the Brazoria Fairway. Both wells have similar weight-percent trends with depth for a portion of the mineralogy. Calcite decreases, and plagioclase, quartz and total clay increase slightly. Within the clays, illite in mixed-layer illite/smectite (I/S) increases and smectite in mixed-layer I/S decreases. Four minerals have distinctly different trends with depth for each well. In the No. 2 Texas State Lease 53034 well, potassium feldspar and mixed-layer I/S decrease, kaolinite increases, and discrete illite is constant. In the No. 1 Pleasant Bayou well, potassium feldspar and kaolinite are constant, mixed-layer I/S increases, and discrete illite decreases.
Date: January 1, 1982
Creator: Freed, R.L.
System: The UNT Digital Library
The comet Giacobini-Zinner magnetotail: Axial stresses and inferred near-nucleus properties (open access)

The comet Giacobini-Zinner magnetotail: Axial stresses and inferred near-nucleus properties

Utilizing the electron and magnetic field data from the ICE tail traversal of Comet Giacobini-Zinner along with the MHD equations, we have developed a steady state, stress balance model of the cometary magnetotail. With it we infer many important but unmeasured ion properties within the G-Z magnetotail both at ICE and upstream at the average point along each streamline where cometary ions are picked-up. The derived tailward ion flow speed at ICE is quite constant at approx.-20 to -30 km/sec across the entire tail. The flow velocity, ion temperature, density, and ion source rates upstream from the lobes (current sheet) at the average pickup locations are approx.-75 km/sec (approx.-12), approx.4 x 10/sup 6/ K (approx.1 x 10/sup 5/), approx.20 /cm/sup 3/ (approx.400), and approx..15 /cm/sup 3//sec (approx.3.6). Gradients in the plasma properties between these two regions are quire strong. Implications of our inferred plasma properties for the near-nucleus region and for cometary magnetotail formation are examined. 9 refs., 1 fig.
Date: October 1, 1986
Creator: McComas, D. J.; Gosling, J. T.; Bame, S. J.; Slavin, J. A.; Smith, E. J. & Steinberg, J. L.
System: The UNT Digital Library
Comparison of the Response of a Nai Scintillation Crystal With a Pressurized Ionization Chamber as a Function of Altitude, Radiation Level and RA-226 Concentration (open access)

Comparison of the Response of a Nai Scintillation Crystal With a Pressurized Ionization Chamber as a Function of Altitude, Radiation Level and RA-226 Concentration

The Grand Junction Uranium Mill Tailings Remedial Action-Radiological Survey Activities Group (UMTRA-RASA) program employs a screening method in which external exposure rates are used to determine if a property contaminated with uranium mill tailings is eligible for remedial action. Portable NaI detectors are used by survey technicians to locate contaminated areas and determine exposure rates. The exposure rate is calculated using a regression equation derived from paired measurements made with a pressurized ionization chamber (PIC) and a NaI detector. During July of 1985 extensive measurements were taken using a PIC and a NaI scintillator with both analogue and digital readout for a wide range of exposure rates and at a variety of elevations. The surface soil was sampled at most of these locations and analyzed for /sup 226/Ra. The response of the NaI detectors was shown to be highly correlated to radiation level but not to /sup 226/Ra concentration or elevation.
Date: January 1, 1986
Creator: Provencher, R.; Smith, G.; Borak, T.B. & Kearney, P.
System: The UNT Digital Library
Dual arm master controller concept (open access)

Dual arm master controller concept

The Advanced Servomanipulator (ASM) slave was designed with an anthropomorphic stance, gear/torque tube power drives, and modular construction. These features resulted in increased inertia, friction, and backlash relative to tape-driven manipulators. Studies were performed which addressed the human factors design and performance trade-offs associated with the corresponding master controller best suited for the ASM. The results of these studies, as well as the conceptual design of the dual arm master controller, are presented. 6 references, 3 figures.
Date: January 1, 1984
Creator: Kuban, D.P. & Perkins, G.S.
System: The UNT Digital Library
Dual arm master controller development (open access)

Dual arm master controller development

The advanced servomanipulator (ASM) slave was designed with an anthropomorphic stance, gear/torque tube power drives, and modular construction. These features resulted in increased inertia, friction, and backlash relative to tape-driven manipulators. Studies were performed which addressed the human factors design and performance trade-offs associated with the corresponding master controller best suited for the ASM. The results of these studies, as well as the conceptual design of the dual arm master controller, are presented. This work was performed as part of the Consolidated Fuel Reprocessing Program at the Oak Ridge National Laboratory. 5 refs., 7 figs., 1 tab.
Date: January 1, 1985
Creator: Kuban, D. P. & Perkins, G. S.
System: The UNT Digital Library
Elements of high constructive deltaic sedimentation, lower Frio Formation, Brazoria County, Texas (open access)

Elements of high constructive deltaic sedimentation, lower Frio Formation, Brazoria County, Texas

The lower Frio Formation in eastern Brazoria County, upper Texas Gulf Coast, was deposited in a high constructive deltaic environment in the Houston delta system. Constructive elements of the stacked, elongate to lobate deltas that were intersected in core are storm induced delta front splays, delta front slump deposits, and distributary mouth bar, distributary channel and delta plain assemblages. Reworked and winnowed abandonment facies that are volumetrically insignificant relative to constructive elements are subdivided into a crossbedded shoreface-foreshore subfacies and a fine grained cyclic sequence of storm deposits on the lower shoreface that represent a distal abandonment subfacies. Micropaleontological evidence indicates that deposition of constructive and abandonment facies took place in water depths of less than 120 feet.
Date: January 1, 1982
Creator: Tyler, N. & Han, J. H.
System: The UNT Digital Library
External flow radiators for reduced space powerplant temperatures. Technical information report (open access)

External flow radiators for reduced space powerplant temperatures. Technical information report

Nuclear space powerplants can operate at temperatures below 900 K and use stainless steel construction without a weight penalty if new radiator concepts can achieve radiator weights of 1-3 kg/m{sup 2}. Conventional tube-and-fin radiators weight about 10 kg/m{sup 2} because of heavy tube walls to prevent meteroid puncture. Radiator designs that do not require meteroid protection are possible; they operate with fluids of low vapor pressure that can be exposed directly to space in external-flow radiators. An example is the {open_quotes}rotating disk radiator{close_quotes} in which centrifugal force drives a liquid film radially outward across a thin rotating metal disk; meteroid punctures cause no loss of fluid other than from evaporation, which can be small. An even lighter concept is the liquid drop radiator in which heat is radiated directly from moving liquid drops. Such radiator concepts look practical, and they may be much easier to develop than the high-temperature, refractory-metal power systems necessitated by conventional radiators.
Date: January 1, 1984
Creator: Elliott, D. G.
System: The UNT Digital Library
Generation of a strong core-centering force in a submillimeter compound droplet system (open access)

Generation of a strong core-centering force in a submillimeter compound droplet system

By amplitude-modulating the driving voltage of an acoustic levitating apparatus, a strong core-centering force can be generated in a submillimeter compound droplet system suspended by the radiation pressure in a gaseous medium. Depending on the acoustic characteristics of the droplet system, it has been found that the technique can be utilized advantageously in the multiple-layer coating of an inertial-confinement-fusion pellet.
Date: January 1, 1981
Creator: Lee, M. C.; Feng, I.; Elleman, D. D.; Wang, T. G. & Young, A. T.
System: The UNT Digital Library
GEOLGY, RESISTIVITY, AND HYDROGEOCHEMISTRY OF THE OJO CALIENTE HOT SPRINGS AREA, NORTHERN NEW MEXICO (open access)

GEOLGY, RESISTIVITY, AND HYDROGEOCHEMISTRY OF THE OJO CALIENTE HOT SPRINGS AREA, NORTHERN NEW MEXICO

Geothermal fluids of the Ojo Caliente area discharge from a northeast trending normal fault that juxtaposes Precambrian metarhyolite and Tertiary sediments. An electrical resistivity survey shows that the fluids emerge from the fault and flow as a plume of thermal water into cold aquifers east of the fault. Geochemistry of fluids indicates a maximum reservoir temperature at depth of 80/sup 0/C with no suggestion of high temperature isotopic exchange between water and reservoir rocks. From this data, it is believed that the Ojo Caliente system is suitable only for small-scale direct use geothermal applications.
Date: October 1, 1982
Creator: Stix, J.; Pearson, C.; Vuataz, F.; Goff, F.; East, J. & Hoffers, B.
System: The UNT Digital Library
Influence of Geometry on Natural Convection in Buildings (open access)

Influence of Geometry on Natural Convection in Buildings

Strong free convection airflows occur within passive solar buildings resulting from elevated temperatures of surfaces irradiated by solar energy compared with the cooler surfaces not receiving radiation. The geometry of a building has a large influence on the directions and magnitudes of natural airflows, and thus heat transfer between zones. This investigation has utilized a variety of reduced-scale building configurations to study the effects of geometry on natural convection heat transfer. Similarity between the reduced-scale model and a full-scale passive solar building is achieved by having similar geometries and by replacing air with Freon-12 gas as the model's working fluid. Filling the model with Freon-12 gas results in similarity in Prandtl numbers and Rayleigh numbers based on temperature differences in the range from 10/sup 9/ to 10/sup 11/. Results from four geometries are described with an emphasis placed on the effects of heat loss on zone temperature stratification shifts.
Date: January 1, 1985
Creator: White, M. D.; Winn, C. B.; Jones, G. F. & Balcomb, J. D.
System: The UNT Digital Library
Interplanetary propulsion using inertial fusion (open access)

Interplanetary propulsion using inertial fusion

Inertial fusion can be used to power spacecraft within the solar system and beyond. Such spacecraft have the potential for short-duration manned-mission performance exceeding other technologies. We are conducting a study to assess the systems aspects of inertial fusion as applied to such missions, based on the conceptual engine design of Hyde (1983) we describe the required systems for an entirely new spacecraft design called VISTA that is based on the use of DT fuel. We give preliminary design details for the power conversion and power conditioning systems for manned missions to Mars of total duration of about 100 days. Specific mission performance results will be published elsewhere, after the study has been completed.
Date: January 1, 1987
Creator: Orth, C.D.; Hogan, W.J.; Hoffman, N.; Murray, K.; Klein, G. & Diaz, F.C.
System: The UNT Digital Library
Investigation of the Pathway of Contaminated Soil Transported to Plant Surfaces by Raindrop Splash (open access)

Investigation of the Pathway of Contaminated Soil Transported to Plant Surfaces by Raindrop Splash

The environmental transport pathway of soil-borne radioisotopes to vegetation surfaces via raindrop splash was studied. The data show that soil can significantly contribute to the contamination found on plants. Further detailed study is needed to calculate the rate constant for the raindrop splash and retention pathways. 8 references, 1 figure. (ACR)
Date: October 21, 1983
Creator: Dreicer, M.; Hakonson, T. E.; Whicker, F. W. & White, G. C.
System: The UNT Digital Library
Low Energy X-Ray Spectra Measured With a Mercuric Iodide Energy Dispersive Spectrometer in a Scanning Electron Microscope (open access)

Low Energy X-Ray Spectra Measured With a Mercuric Iodide Energy Dispersive Spectrometer in a Scanning Electron Microscope

A mercuric iodide energy dispersive x-ray spectrometer, with Peltier cooling provided for the detector and input field effect transistor, has been developed and tested in a scanning electron microscope. X-ray spectra were obtained with the 15 keV electron beam. An energy resolution of 225 eV (FWHM) for Mn-K/sub ..cap alpha../ at 5.9 keV and 195 eV (FWHM) for Mg-K line at 1.25 keV has been measured. Overall system noise level was 175 eV (FWHM). The detector system characterization with a carbon target demonstrated good energy sensitivity at low energies and lack of significant spectral artifacts at higher energies. 16 refs., 5 figs.
Date: January 1, 1985
Creator: Iwanczyk, J. S.; Dabrowski, A. J.; Huth, G. C.; Bradley, J. G.; Conley, J. M. & Albee, A. L.
System: The UNT Digital Library
Mathematical simulation of contaminant distribution in and around the uranium mill tailing piles, Riverton, Wyoming (open access)

Mathematical simulation of contaminant distribution in and around the uranium mill tailing piles, Riverton, Wyoming

As part of the Research and Development phase of the Uranium Mill Tailings Remedial Action (UMTRA) program, the Lawrence Berkeley Laboratory (LBL) has set itself the goal of explaining the physico-chemical evolution of the Riverton site on the basis of the already collected field data at the site (Tokunaga and Narasimhan, 1982, Smith and Moed, 1982; White et al., 1984). The predictive aspects as well as addressing the question of critical quantity of field data have to be considered during the design phase of the project as a joint effort between the LBL team and the construction engineers. At the present time, LBL is in the process of completing the Research and Development phase of the work. As of this writing, the development of an appropriate set of mathematical models has been completed. The computations of the soil-water regime at the upper tailings surface, involving climatological factors is nearing completion. Computations of chemical transport are still in progress. This paper is devoted to a description of the key mathematical issues, the mathematical models that are needed to address these issues and a discussion of the model results pertaining to the soil water regime at the tailings-atmosphere interface. 11 references, 3 …
Date: February 1, 1983
Creator: Narasimhan, T. N.; Tokunaga, T.; White, A. F. & Smith, A. R.
System: The UNT Digital Library
MHD waves detected by ice at distances > 28 x 10/sup 6/ km from Comet Halley: Cometary or solar wind origin (open access)

MHD waves detected by ice at distances > 28 x 10/sup 6/ km from Comet Halley: Cometary or solar wind origin

Spectral analyses of the high resolution magnetic field data are employed to determine if there is evidence of cometary heavy ion pickup when ICE was closest to Halley, approx.28 x 10/sup 6/ km. No evidence is found for the presence of heavy ion cyclotron waves. However, from this search, two new wave modes are discovered in the solar wind: electromagnetic ion cyclotron waves and drift mirror mode waves. Both modes have scales of 10 to 60 s (1 to 6 T/sub p/) in the spacecraft frame. The possibility of wave generation by cometary hydrogen pickup is explored. Theoretical arguments and further experimental evidence indicates that cometary origin is improbable. The most likely source is plasma instabilities associated with solar wind stream-stream interactions. VLF electrostatic emissions are found to occur in field minima or at gradients of the drift mirror structures. Possible generation mechanisms of drift mirror mode waves, cyclotron waves and electrostatic waves are discussed.
Date: January 1, 1986
Creator: Tsurutani, B. T.; Brinca, A. L.; Smith, E. J.; Thorne, R. M.; Scarf, F. L.; Gosling, J. T. et al.
System: The UNT Digital Library
Neutral sheet crossings in the distant magnetotail (open access)

Neutral sheet crossings in the distant magnetotail

We have analyzed the magnetic field data from ISEE-3 in the distant magnetotail for 18 crossings of the cross-tail current sheet (or so-called natural sheet) to determine the direction of the normal component B/sub z/. The crossings occurred near the middle of the aberrated magnetotail (0 < y < 30 R/sub e, -10 < z < 5) in GSM coordinates, at a distance of about 220 R/sub e/, January 28 to February 12, 1983; in each case the plasma flow velocity was tailward. In 2 cases we found B/sub z/ negative (southward), as would be required with a magnetic neutral line (reconnection line) earthward of the spacecraft. In 12 cases B/sub z/ was clearly northward (B/sub z/ > 0.4 nT), consistent with closed field lines connected to the earth. In 3 cases B/sub z/ was very close to zero; in several instances there was structure in B/sub y/, suggesting localized currents with x or z directions. One may have been a magnetopause crossing. The strong preponderance of northward B/sub z/ favors a model of the magnetotail which is dominated by boundary layer plasma, flowing tailward on closed magnetic field lines, which requires the existence of an electric field in the …
Date: January 1, 1985
Creator: Heikkila, W. J.; Slavin, J. A.; Smith, E. J.; Baker, D. N. & Zwickl, R. D.
System: The UNT Digital Library
Numerical Calculation of the Three Dimensional Electrical Field in the Central Region of a Cyclotron (open access)

Numerical Calculation of the Three Dimensional Electrical Field in the Central Region of a Cyclotron

To provide detailed and accurate electric fields in the ion source-puller region and at the dee dummy-dee gap for a cyclotron, a relaxation method solution of Laplace's equation has been used. A conventional difference equation with variation in mesh size and relaxation factor as well as different schemes for boundary corrections have been developed to achieve roughly 1 percent accuracy for a thre-dimensional domain with 10/sup 6/ mesh points. Although the computation requires considerable computer time, it is much less expensive than electrolytic tank analogue methods for measuring field distributions around complex electrode configurations.
Date: January 1, 1981
Creator: Chen, M. & Lind, D. A.
System: The UNT Digital Library
Observations of heavy energetic ions for upstream from comet Halley (open access)

Observations of heavy energetic ions for upstream from comet Halley

On March 25, 1986, the ICE spacecraft came within 28 x 10/sup 6/ km of the nucleus of comet Halley. For several days around this time, bursts of heavy ions were observed by the ICE energetic ion experiment. These bursts were observed only during periods when the solar wind velocity was considerably higher than its nominal value. We examine the characteristics of these ions, in particular their anisotropies. Using the well known formulae for transformation of distributions from the solar wind frame of reference to the spacecraft frame, we examine the angular distributions expected from either protons, or heavy ions from the water group, and show that the measurements are consistent with heavy ions, and not with protons. We discuss other sources of heavy ions and conclude that the most likely source of these ions is comet Halley. 9 refs., 5 figs.
Date: January 1, 1986
Creator: Sanderson, T. R.; Wenzel, K. P.; Daly, P. W.; Cowley, S. W. H.; Hynds, R. J.; Richardson, I. G. et al.
System: The UNT Digital Library
The P/Giacobini-Zinner Magnetotail (open access)

The P/Giacobini-Zinner Magnetotail

On September 11, 1985 the International Cometary Explorer passed behind Comet Giacobini-Zinner with a closest approach distance of 7800 km. In agreement with Alfven's interplanetary magnetic field line draping model of cometary type I tails, a well defined 1 x 10/sup 4/ km diameter magnetotail was observed downstream of the inner coma. This study uses the ICE magnetic field, plasma electron, plasma wave, and energetic ion observations to investigate the structure and stability of the Giacobini-Zinner magnetic tail. Emphasis is placed on the identification of differences and similarities between cometary and planetary magnetotails. Finally, the ICE magnetotail observations are discussed in relation to the global solar wind interaction with P/Giacobini-Zinner. 33 refs., 8 figs.
Date: January 1, 1986
Creator: Slavin, J. A.; Smith, E. J.; Daly, P. W.; Flammer, K. R.; Gloeckler, G.; Goldberg, B. A. et al.
System: The UNT Digital Library
Papers Presented - Geothermal Resources Council 1980 Annual Meeting (open access)

Papers Presented - Geothermal Resources Council 1980 Annual Meeting

This report contains preprints of papers pertaining to geothermal energy development in the Eastern United States written by members of the Center for Metropolitan Planning and Research (Metro Center) and by the Applied Physics Laboratory (APL) both of The Johns Hopkins University.
Date: October 1, 1980
Creator: unknown
System: The UNT Digital Library
Pathway: A Simulation Model of Radionuclide-Transport Through Agricultural Food Chains (open access)

Pathway: A Simulation Model of Radionuclide-Transport Through Agricultural Food Chains

PATHWAY simulates the transport of radionuclides from fallout through an agricultural ecosystem. The agro-ecosystem is subdivided into several land management units, each of which is used either for grazing animals, for growing hay, or for growing food crops. The model simulates the transport of radionuclides by both discrete events and continuous, time-dependent processes. The discrete events include tillage of soil, harvest and storage of crops,and deposition of fallout. The continuous processes include the transport of radionuclides due to resuspension, weathering, rain splash, percolation, leaching, adsorption and desorption of radionuclides in the soil, root uptake, foliar absorption, growth and senescence of vegetation, and the ingestion assimilation, and excretion of radionuclides by animals. Preliminary validation studies indicate that the model dynamics and simulated values of radionuclide concentrations in several agricultural products agree well with measured values when the model is driven with site specific data on deposition from world-wide fallout.
Date: January 1, 1982
Creator: Kirchner, T. B.; Whicker, F. W. & Otis, M. D.
System: The UNT Digital Library
PEGASUS: a multi-megawatt nuclear electric propulsion system (open access)

PEGASUS: a multi-megawatt nuclear electric propulsion system

With the Space Transportation System (STS), the advent of space station Columbus and the development of expertise at working in space that this will entail, the gateway is open to the final frontier. The exploration of this frontier is possible with state-of-the-art hydrogen/oxygen propulsion but would be greatly enhanced by the higher specific impulse of electric propulsion. This paper presents a concept that uses a multi-megawatt nuclear power plant to drive an electric propulsion system. The concept has been named PEGASUS, PowEr GenerAting System for Use in Space, and is intended as a ''work horse'' for general space transportation needs, both long- and short-haul missions. The recent efforts of the SP-100 program indicate that a power system capable of producing upwards of 1 megawatt of electric power should be available in the next decade. Additionally, efforts in other areas indicate that a power system with a constant power capability an order of magnitude greater could be available near the turn of the century. With the advances expected in megawatt-class space power systems, the high specific impulse propulsion systems must be reconsidered as potential propulsion systems. The power system is capable of meeting both the propulsion system and spacecraft power requirements.
Date: June 1, 1985
Creator: Coomes, Edmund P.; Cuta, Judith M.; Webb, Brent J. & King, David Q.
System: The UNT Digital Library
Phytoplankton Dynamics in Oceanic Waters Off Ke-Ahole Point, Hawaii (open access)

Phytoplankton Dynamics in Oceanic Waters Off Ke-Ahole Point, Hawaii

Phytoplankton activity in an oligotrophic environment was studied on six cruises over a 14-month period. Phytoplankton biomass and productivity displayed considerable temporal variability despite the relative constancy of the physical and chemical environment. No evidence of seasonality or diurnal variability in phytoplankton biomass was observed. Annual average (+ s.d.) depth-integrated values (0-260 m) for chlorophyll a, phaeopigment, ATP, and primary productivity were 24.55 + 10.31 mg {center_dot} m{sup -2}, 11.81 + 7.20 mg {center_dot} m{sup -2}, 3.00 + 1.78 mg {center_dot} m{sup -2}, and 8.79 + 7.82 mg C {center_dot} m{sup -2}, h{sup -1}, respectively; over the year these parameters were seen to vary over ranges of 3X, 6X, 10X, and 26X, respectively. The mean depths of the chlorophyll and phaeopigment maxima were 85 + 9 m and 95 + 11 m, respectively; the pheopigment maximum was always located at or below that of chlorophyll. Size fractionation studies showed that at this oceanic station about 80% of the phytoplankton biomass occurred in the &lt; 5 {micro}m fraction. Low ambient nutrient levels were typical at the depth of the chlorophyll maximum, indicating that nutrient assimilation was actively occurring in that layer. Elevated nutrient levels were typical at the deeper phaeopigment maximum …
Date: July 1, 1980
Creator: Bienfang, Paul K. & Szyper, James P.
System: The UNT Digital Library
Plasma properties of driver gas following interplanetary shocks observed by ISEE-3 (open access)

Plasma properties of driver gas following interplanetary shocks observed by ISEE-3

Plasma fluid parameters calculated from solar wind and magnetic field data obtained on ISEE 3 were studied to determine the characteristic properties of driver gas following interplanetary shocks. Of 54 shocks observed from August 1978 to February 1980, 9 contained a well defined driver gas that was clearly identifiable by a discontinuous decrease in the average proton temperature across a tangential discontinuity. While helium enhancements were present in all of 9 of these events, only about half of them contained simultaneous changes in the two quantities. Often the He/H ratio changed over a period of minutes. Simultaneous with the drop in proton temperature the helium and electron temperature decreased abruptly. In some cases the proton temperature depression was accompanied by a moderate increase in magnetic field magnitude with an unusually low variance and by an increase in the ratio of parallel to perpendicular temperature. The drive gas usually displayed a bi-directional flow of suprathermal solar wind electrons at higher energies (>137 eV).
Date: January 1, 1982
Creator: Zwickl, R. D.; Asbridge, J. R.; Bame, S. J.; Feldman, W. C.; Gosling, J. T. & Smith, E. J.
System: The UNT Digital Library