Resource Type

2,307 Matching Results

Results open in a new window/tab.

Kriging for interpolation of sparse and irregularly distributed geologic data (open access)

Kriging for interpolation of sparse and irregularly distributed geologic data

For many geologic problems, subsurface observations are available only from a small number of irregularly distributed locations, for example from a handful of drill holes in the region of interest. These observations will be interpolated one way or another, for example by hand-drawn stratigraphic cross-sections, by trend-fitting techniques, or by simple averaging which ignores spatial correlation. In this paper we consider an interpolation technique for such situations which provides, in addition to point estimates, the error estimates which are lacking from other ad hoc methods. The proposed estimator is like a kriging estimator in form, but because direct estimation of the spatial covariance function is not possible the parameters of the estimator are selected by cross-validation. Its use in estimating subsurface stratigraphy at a candidate site for geologic waste repository provides an example.
Date: December 31, 1986
Creator: Campbell, K.
System: The UNT Digital Library
Occurrence of fracture-lining manganese minerals in silicic tuffs, Yucca Mountain, Nevada, USA (open access)

Occurrence of fracture-lining manganese minerals in silicic tuffs, Yucca Mountain, Nevada, USA

Yucca Mountain, in southern Nevada, is being studied by the Nevada Nuclear Waste Storage Investigations (NNWSI) Project as a potential site for an underground high-level nuclear waste repository. The site is within Miocene volcanic rocks that are 1.5 to 4 km thick and range in age from 12.5 to 14 MY. Several holes have been drilled in Yucca Mountain for geologic and hydrologic studies. Drill hole USW G-4, the most recently cored hole within the potential repository block, was chosen for detailed study of fracture-filling minerals because it is closest to the planned NNWSI exploratory shaft. Drill hole USW G-4 was drilled to 914.7 m (3001 ft) and continuously cored from 6.7 m (22 ft) to total depth (TD). The drilling history, lithology of the core, and geophysical logs of the well were published earlier. Because manganese oxides in fractures may act as a natural barrier to radionuclide migration, it is important to determine exactly which manganese minerals are present, in what intervals they occur, and how extensive these fracture coatings are.
Date: December 31, 1986
Creator: Carlos, Barbara Arney
System: The UNT Digital Library
Zeolitic alteration and fracture fillings in silicic tuffs at a potential nuclear waste repository, Yucca Mountain, Nevada, USA (open access)

Zeolitic alteration and fracture fillings in silicic tuffs at a potential nuclear waste repository, Yucca Mountain, Nevada, USA

This paper describes the distribution and chemistry of zeolites in tuffs and in fractures at Yucca Mountain. Samples used in this study were collected from continuously-cored exploratory drill holes. A variety of analytical techniques, including optical petrography, x-ray powder diffraction, electron microanalysis, and x-ray fluorescence, were used to characterize the distribution and chemistry of zeolites in these samples.
Date: December 31, 1986
Creator: Broxton, David E. & Carlos, Barbara Arney
System: The UNT Digital Library
A self-similar approach to the explosion of droplets by a high energy laser beam (open access)

A self-similar approach to the explosion of droplets by a high energy laser beam

A model has been constructed in which a small droplet is exploded by the absorption of energy from a high energy laser beam. The beam flux is so high that it is assumed that a plasma is formed. A single-fluid model of a plasma droplet interacting with laser radiation is used. Selfsimilarity is invoked to reduce the spherically symmetric problem involving hydrodynamics and Maxwell's equations to quadrature. It is shown analytically that the model reproduces in qualitative manner certain features observed experimentally.
Date: December 30, 1986
Creator: Chitanvis, S.M.
System: The UNT Digital Library
Shock wave interaction with turbulence: Pseudospectral simulations (open access)

Shock wave interaction with turbulence: Pseudospectral simulations

Shock waves amplify pre-existing turbulence. Shock tube and shock wave boundary layer interaction experiments provide qualitative confirmation. However, shock pressure, temperature, and rapid transit complicate direct measurement. Computational simulations supplement the experimental data base and help isolate the mechanisms responsible. Simulations and experiments, particularly under reflected shock wave conditions, significantly influence material mixing. In these pseudospectral Navier-Stokes simulations the shock wave is treated as either a moving (tracked or fitted) domain boundary. The simulations assist development of code mix models. Shock Mach number and pre-existing turbulence intensity initially emerge as key parameters. 20 refs., 8 figs.
Date: December 30, 1986
Creator: Buckingham, A.C.
System: The UNT Digital Library
Cost Optimization of Induction Linac Drivers for Linear Colliders (open access)

Cost Optimization of Induction Linac Drivers for Linear Colliders

Recent developments in high reliability components for linear induction accelerators (LIA) make possible the use of these devices as economical power drives for very high gradient linear colliders. A particularly attractive realization of this ''two-beam accelerator'' approach is to configure the LIA as a monolithic relativistic klystron operating at 10 to 12 GHz with induction cells providing periodic reacceleration of the high current beam. Based upon a recent engineering design of a state-of-the-art, 10- to 20-MeV LIA at Lawrence Livermore National Laboratory, this paper presents an algorithm for scaling the cost of the relativistic klystron to the parameter regime of interest for the next generation high energy physics machines. The algorithm allows optimization of the collider luminosity with respect to cost by varying the characteristics (pulse length, drive current, repetition rate, etc.) of the klystron. It also allows us to explore cost sensitivities as a guide to research strategies for developing advanced accelerator technologies.
Date: December 29, 1986
Creator: Barletta, W. A.
System: The UNT Digital Library
The Edwards Family and Black Entrepreneurial Success (open access)

The Edwards Family and Black Entrepreneurial Success

Article relates the success story of Walter James and Frances Giliam Edwards, black entrepreneurs in Oklahoma in the early 1900s. Paul Lehman discusses how their housing development business and their contribution to the founding of Edwards Memorial Hospital were landmarks in working towards racial equality.
Date: Winter 1986
Creator: Lehman, Paul
System: The Gateway to Oklahoma History
For the Record, Winter 1986-87 (open access)

For the Record, Winter 1986-87

For the Record section including the minutes of the quarterly board meeting of the Board of Directors of the Oklahoma Historical Society that was held on July 22, 1986.
Date: Winter 1986
Creator: Oklahoma Historical Society
System: The Gateway to Oklahoma History
Notes and Documents, Winter 1986-87 (open access)

Notes and Documents, Winter 1986-87

Notes and Documents column including a letter from Cyrus Byington to his daughter Lucy and her husband, George Dana II. An introduction by Louis Coleman illustrates its connection to Coleman's article in this issue, "Twenty-five Days to the Choctaw Nation."
Date: Winter 1986
Creator: Coleman, Louis & Byington, Cyrus
System: The Gateway to Oklahoma History
Plight of the Tonkawas 1875 to 1898 (open access)

Plight of the Tonkawas 1875 to 1898

Article describes the plight of the Tonkawa people, who had assisted the U.S. Army but were ill-treated and shuffled around to numerous locations in search of a home. Thomas F. Schilz describes the process of their movement from Fort Griffin in Texas to Indian Territory, and how government officials handled the situation.
Date: Winter 1986
Creator: Schilz, Thomas F.
System: The Gateway to Oklahoma History
The Political Career of Patrick S. Nagle "Champion of the Underdog" (open access)

The Political Career of Patrick S. Nagle "Champion of the Underdog"

Article describes the life and career of Patrick S. Nagle, a candidate for U.S. Senator who switched party affiliations and transformed from a Democrat to an active Socialist. R. O. Joe Cassity, Jr. explores the impact of Nagle's efforts as well as the ideology that drove Nagle.
Date: Winter 1986
Creator: Cassity, R. O. Joe, Jr.
System: The Gateway to Oklahoma History
Twenty-five Days to the Choctaw Nation (open access)

Twenty-five Days to the Choctaw Nation

Article provides historical context for the journal entries of George Dana II, which relay the course of his difficult journey from Ohio to the Choctaw Nation to reunite with his bride-to-be, Lucy Byington.
Date: Winter 1986
Creator: Coleman, Louis
System: The Gateway to Oklahoma History
Wagoner, I.T. "Queen City of the Prairies" (open access)

Wagoner, I.T. "Queen City of the Prairies"

Article describes the founding and growth of the City of Wagoner in the wake of its upcoming centennial. Brad Agnew discusses the conflict that occurred as one of the towns in Indian Territory attempted to achieve self-determination in a diverse area, the education system that evolved there, and the crime that threatened Wagoner's railroads.
Date: Winter 1986
Creator: Agnew, Brad
System: The Gateway to Oklahoma History
An overview of the Lawrence Livermore National Laboratory Free Electron Laser Program (open access)

An overview of the Lawrence Livermore National Laboratory Free Electron Laser Program

This paper reviews the status of the LLNL Free Electron Laser Program. Rather than using the output of an rf linac, the electron pulse from an induction linac enters the wiggler magnet without being bunched into small packets. The laser beam makes a single pass through the FEL amplifier. Wavelengths from several millimeters to less than 10/sup -6/m can be amplified. (JDH)
Date: December 18, 1986
Creator: Shay, H.D.
System: The UNT Digital Library
Laboratory performance testing of an extruded bitumen containing a surrogate, sodium nitrate-based, low-level aqueous waste (open access)

Laboratory performance testing of an extruded bitumen containing a surrogate, sodium nitrate-based, low-level aqueous waste

Laboratory results of a comprehensive, regulatory performance test program, utilizing an extruded bitumen and a surrogate, sodium nitrate-based waste, have been compiled at the Oak Ridge National Laboratory (ORNL). Using a 53 millimeter, Werner and Pfleiderer extruder, operated by personnel of WasteChem Corporation of Paramus, New Jersey, laboratory-scale, molded samples of type three, air blown bitumen were prepared for laboratory performance testing. A surrogate, low-level, mixed liquid waste, formulated to represent an actual on-site waste at ORNL, containing about 30 wt % sodium nitrate, in addition to eight heavy metals, cold cesium and strontium was utilized. Samples tested contained three levels of waste loading: that is, forty, fifty and sixty wt % salt. Performance test results include the ninety day ANS 16.1 leach test, with leach indices reported for all cations and anions, in addition to the EP Toxicity test, at all levels of waste loading. Additionally, test results presented also include the unconfined compressive strength and surface morphology utilizing scanning electron microscopy. Data presented include correlations between waste form loading and test results, in addition to their relationship to regulatory performance requirements.
Date: December 15, 1986
Creator: Mattus, A. J. & Kaczmarsky, M. M.
System: The UNT Digital Library
Bottom Quark Production At The SSC (Superconducting Super Collider) (open access)

Bottom Quark Production At The SSC (Superconducting Super Collider)

We present predictions for the rapidity and transverse momentum distributions for inclusive production of bottom quarks at SSC energies, pp ..-->.. bX. Our computations are based on the simplest, lowest-order QCD mechanisms. To estimate uncertainties, we use three different choices for structure functions, G(x,Q), as well as different choices for the evolution scale Q.
Date: December 8, 1986
Creator: Berger, Edmond L.; Collins, John C. & Soper, Davison E.
System: The UNT Digital Library
Radiation associated with an inertial confinement fusion laser system (open access)

Radiation associated with an inertial confinement fusion laser system

The primary objective the LLNL Laser Fusion Program is to understand and develop the science and technology of inertial confinement fusion. Nova, a 100-TW/100-kJ laser system, has demonstrated efficient compression, ignition, and burn of D-T fusion fuel. The LLNL fusion computer program (LASNEX) and experiments strongly support achieving high gain with the proposed multi-MJ laser system. In this paper, I examine the prompt and residual radiations associated with these laser systems. 3 refs., 6 figs., 4 tabs.
Date: December 3, 1986
Creator: Singh, M.S.
System: The UNT Digital Library
Annealing of cold worked hypostoichiometric Ni/sub 3/Al alloys using positron lifetime spectroscopy (open access)

Annealing of cold worked hypostoichiometric Ni/sub 3/Al alloys using positron lifetime spectroscopy

Hypostoichiometric Ni/sub 3/Al alloys of composition 76.2 Ni:23.8 Al containing impurity levels of boron and hafnium were either cold rolled or pressed. Rolled and pressed samples were deformed by 20% and 10% thickness reductions, respectively. Samples were annealed isochronally at approximately 50/sup 0/C intervals up to 1050/sup 0/C. Two major annealing stages were apparent in all three alloys studied. These could be attributed to vacancy migration to sinks and annealing of dislocations and(or) recrystallization. The onset of vacancy migration occurred at approximately 200/sup 0/C in all three alloys. Annealing of dislocations started at 650/sup 0/C to 700/sup 0/C and was complete at 1000/sup 0/C for alloys which contained boron and or hafnium impurities. In the pure alloy the onset of dislocation annealing occurred at 800/sup 0/C and was incomplete at the highest (1050/sup 0/C) annealing temperatures reached.
Date: December 1, 1986
Creator: Usmar, S.G. & Lynn, K.G.
System: The UNT Digital Library
Concluding talk-seminar on critical issues in development of new linear colliders (open access)

Concluding talk-seminar on critical issues in development of new linear colliders

The growth of particle colliders is summarized, with their collision energy in the frame of the elementary constituents given for numerous specific machines. The logic concerning the design of electron-positron colliders and definition of parameters are briefly discussed. Several issues are covered which are presently uncertain, including beamstrahlung and interaction among beams of transverse dimensions in the angstrom range. Alternate power sources and their economy are considered as well as superconducting structures. (LEW)
Date: December 1, 1986
Creator: Panofsky, W.K.H.
System: The UNT Digital Library
Contamination layers on EUV (extreme ultraviolet) reflectors (open access)

Contamination layers on EUV (extreme ultraviolet) reflectors

We have utilized a visible in situ ellipsometer to investigate the growth of oxide surface layers on aluminum and silicon films deposited in an ultra high vacuum (UHV) system. A single molecular layer of oxide forms on the aluminum film surface in 1 hour when exposed to a partial pressure of 2 x 10/sup -8/ Torr of either oxygen or water vapor. The single molecular oxide layer that forms in 4 hours on silicon when exposed to 2.5 x 10/sup -8/ Torr of oxygen is SiO/sub 2/ if the vacuum ion gauges are operating, but it appears to be SiO if these gauges are turned off during the layer formation. The time of formation of these layers is inversely proportional to pressure. The growth rate of the oxide surface layer drops dramatically after formation of this first monolayer on both aluminum and silicon. Other gases, such as methane and carbon monoxide, were found to be essentially unreactive with the aluminum film.
Date: December 1, 1986
Creator: Scott, M. L.; Arendt, P. N.; Cameron, B. J. & Newnam, B.
System: The UNT Digital Library
Copper corrosion in irradiated environments: The influence of H{sub 2}O{sub 2}on the electrochemistry of copper dissolution in HCl electrolyte (open access)

Copper corrosion in irradiated environments: The influence of H{sub 2}O{sub 2}on the electrochemistry of copper dissolution in HCl electrolyte

The anodic dissolution of copper was examined in deaerated, 0.1 M HCl aqueous solution in the presence of H{sub 2}O{sub 2}. Concentrations of H{sub 2}O{sub 2} up to 0.2 M were studied at a rotating copper disk-platinum ring electrode. The open circuit potential (OCP) of copper was found to depend on both peroxide concentration and rotation rate. The OCP shifts towards more positive values with increasing H{sub 2}O{sub 2} concentration (C) and decreasing rotation rate. The current-voltage curves for anodic dissolution of copper were also influenced by the presence of peroxide. The curves recorded with the potential scanned in the positive direction showed the expected 60 mV slope, but the reverse scans showed significant departures. At a given potential scan rate, hysteresis was observed which was larger for higher H{sub 2}O{sub 2} concentrations, lower rotation rates, and more positive anodic potential limits. Monitoring the cuprous ions at the outer Pt ring revealed that there was a complex set of events taking place at the copper surface, including film formation and the appearance of cupric ions. 13 refs., 7 figs.
Date: December 1, 1986
Creator: Smyrl, W. H.; Bell, B. T.; Atanasoski, R. T. & Glass, R. S.
System: The UNT Digital Library
A core hole in the southwestern moat of the Long Valley caldera: Early results (open access)

A core hole in the southwestern moat of the Long Valley caldera: Early results

A continuously cored hole penetrated 715m into the southwestern moat of the Long Valley caldera. Temperatures in the post-caldera deposits increase rapidly with depth over the upper 335m to 202/sup 0/C, then remain nearly isothermal into the Bishop Tuff to the bottom of the hole. The depth to the Bishop is the shallowest, and the temperatures observed are among the highest in holes drilled in the caldera. The hole identifies a potential geothermal resource for the community of Mammoth Lakes, constrains the position of the principal heat source for the caldera's hydrothermal system, and serves as access for monitoring changes in water level, temperatures, and fluid chemistry.
Date: December 1, 1986
Creator: Wollenberg, H. A.; Sorey, M. L.; Farrar, C. D.; White, A. F.; Flexser, S. & Bartel, L. C.
System: The UNT Digital Library
Coupled processes in single fractures, double fractures and fractured porous media (open access)

Coupled processes in single fractures, double fractures and fractured porous media

The emplacement of a nuclear waste repository in a fractured porous medium provides a heat source of large dimensions over an extended period of time. It also creates a large cavity in the rock mass, changing significantly the stress field. Such major changes induce various coupled thermohydraulic, hydromechanic and hydrochemical transport processes in the environment around a nuclear waste repository. The present paper gives, first, a general overview of the coupled processes involving thermal, mechanical, hydrological and chemical effects. Then investigations of a number of specific coupled processes are described in the context of fluid flow and transport in a single fracture, two intersecting fractures and a fractured porous medium near a nuclear waste repository. The results are presented and discussed.
Date: December 1, 1986
Creator: Tsang, C. F.
System: The UNT Digital Library
The development of a cavitation free sodium pump for the breeder reactor (open access)

The development of a cavitation free sodium pump for the breeder reactor

The sodium pumps for a liquid metal fast breeder reactor must be designed for exceptionally high reliability and long life. The principal adverse factor which tends to limit the primary pump life is cavitation which becomes potentially severe under off-design flow conditions caused by the requirement of two loop operations which resulted in a large operating flow range. This problem prompted an extensive study which included experimental investigations of scaled down and full size pumps. The investigations involved visual observations, acoustic signature recordings, and physical characteristic measurements of the model and full size impellers. The blade configuration of the model was modified several times. After each modification intensive testing was conducted with feedback to established design criteria. The results obtained from the final configuration showed excellent cavitation performance. This configuration was then machined on the full scale impeller and tested. The results confirmed acceptable performance in the entire range of operating conditions. This paper describes the test facilities erected for this study, discusses the experimental techniques employed, and presents the experimental techniques employed, and presents a sample of the experimental results.
Date: December 1, 1986
Creator: Baladi, J. Y. & Nyilas, C. P.
System: The UNT Digital Library