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Geotomography applied at the Stripa Mine in Sweden
LLNL made ultrahigh-frequency (450-MHz) electromagnetic borehole-to-borehole transmissions in the Stripa Mine near Guldsmedshyttan, Sweden, in April 1979. Transmission loss measurements were made between four sets of 76-mm boreholes 30 m long, located at the end of a drift. Distances between the boreholes varied from 2 to 22 m. More than 25,000 data points were taken. A geotomograph was constructed to show the variation of attenuation between boreholes. The observed spatial variation of electromagnetic attenuation may be related to the expected stress relief created by the mine. Transmission loss measurements were also made between two converging boreholes drilled from the surface to points near the mine. Data taken at 21 MHz show a nearly uniform attenuation within this sampled region. These experiments demonstrate that geotomographic data collection/interpretation provides high-resolution images of the underground environment and can provide useful input to those charged with providing the detailed site characterizations needed for both short- and long-term monitoring of underground nuclear waste repositories.
Date:
April 7, 1980
Creator:
Okada, J.T.; Laine, E.F.; Lytle, R.J. & Daily,W.D.
Object Type:
Report
System:
The UNT Digital Library
Spatial averaging algorithms for ultrasonic inspection of austenitic stainless steel welds
Interpretation of ultrasonic inspection data from stainless steel welds is difficult because the signal-to-noise ratio is very low. The three main reasons for this are the granular structure of the weld, the high attenuation of stainless steel, and electronic noise. Averaging in time at the same position in space reduces electronic noise, but does not reduce ultrasonic noise from grain boundary scattering. Averaging wave-forms from different spatial positions helps reduce grain noise, but desired signals can destructively interfere if they shift in time. If the defect geometry is known, the ultrasonic waveforms can be shifted before averaging, ensuring signal reinforcement. The simplest geometry results in a linear time shift. An averaging algorithm has been developed which finds the optimum shift. This algorithm computes the averaged, or composite waveform as a function of the time shift. The optimum occurs when signals from a reflector become aligned in time, producing a large amplitude composite waveform. This algorithm works very well, but requires significant computer time and storage. This paper discusses this linear shift averaging algorithm, and considers an implementation using frequency domain techniques. Also, data from several weld defects are presented and analyzed.
Date:
April 7, 1980
Creator:
Horn, J. E.; Cooper, C.S. & Michaels, T.E.
Object Type:
Article
System:
The UNT Digital Library
Application of the Argonne Advanced Acceleration Test Facility to development for conventional accelerators
The Argonne Advanced Acceleration Test Facility is designed as a powerful tool to test ideas for very high gradient acceleration schemes based on direct beam excitation of plasmas, metal structures, dielectrics, etc. The characteristic size in these systems is )approximately) 1 cm, corresponding to frequencies )approximately) 10 GHz. The question addressed here is whether the special features of this facility have application as well to the development of components for the more conventional, lower frequency, accelerators now operating or under development. It is suggested that the usefulness of the facility for the development of conventional systems could be enhanced by a provision for longer time delay between driver and witness beam pulses. 9 refs., 2 figs.
Date:
April 7, 1988
Creator:
MacLachlan, J.A.
Object Type:
Report
System:
The UNT Digital Library
Suppression of transverse beam breakup modes in an induction accelerator by gas focusing
The effect of beam-generated positive ions on the beam-breakup instability in linear electron accelerators is calculated using simple models. The strongly nonlinear dependence of the ion focusing force on radius makes a complete suppression of the mode growth possible, in contrast to solenoidal focusing. The predicted gas pressures for significant stabilization of the mode growth in a machine configuration like ATA is relatively low (10/sup -5/ to 10/sup -4/ torr), even for high-Q modes.
Date:
April 7, 1980
Creator:
Briggs, R. J.
Object Type:
Report
System:
The UNT Digital Library
Role of human- and animal-sperm studies in the evaluation of male reproductive hazards
Human sperm tests provide a direct means of assessing chemically induced spermatogenic dysfunction in man. Available tests include sperm count, motility, morphology (seminal cytology), and Y-body analyses. Over 70 different human exposures have been monitored in various groups of exposed men. The majority of exposures studied showed a significant change from control in one or more sperm tests. When carefully controlled, the sperm morphology test is statistically the most sensitive of these human sperm tests. Several sperm tests have been developed in nonhuman mammals for the study of chemical spermatotoxins. The sperm morphology test in mice has been the most widely used. Results with this test seem to be related to germ-cell mutagenicity. In general, animal sperm tests should play an important role in the identification and assessment of potential human reproductive hazards. Exposure to spermatotoxins may lead to infertility, and more importantly, to heritable genetic damage. While there are considerable animal and human data suggesting that sperm tests may be used to detect agents causing infertility, the extent to which these tests detect heritable genetic damage remains unclear. (ERB)
Date:
April 7, 1982
Creator:
Wyrobek, A.J.; Gordon, L. & Watchmaker, G.
Object Type:
Article
System:
The UNT Digital Library
Cost effectiveness of long life incandescent lamps and energy buttons
Long-life replacement lamps for the incandescent lamp have been evaluated with regard to their cost effectiveness. The replacements include the use of energy buttons that extend lamp life as well as an adaptive fluorescent circline lamp that will fit into existing incandescent lamp sockets. The initial, operating, and replacement costs for one million lumen hours are determined for each lamp system. It is found that the most important component lighting cost is the operating cost. Using lamps that are less efficient or devices that cause lamps to operate less efficiently are not cost-effective. The adaptive fluorescent circline lamp, even at an initial unit cost of $20.00, is the most cost-effective source of illumination compared to the incandescent lamp and lamp systems examined.
Date:
April 7, 1980
Creator:
Verderber, R. & Morse, O.
Object Type:
Report
System:
The UNT Digital Library
The Tulia Herald (Tulia, Tex.), Vol. 80, No. 14, Ed. 1 Thursday, April 7, 1988
Weekly newspaper from Tulia, Texas that includes local, state and national news along with extensive advertising.
Date:
April 7, 1988
Creator:
Tooley, Wendell
Object Type:
Newspaper
System:
The Portal to Texas History
The Canadian Record (Canadian, Tex.), Vol. 98, No. 14, Ed. 1 Thursday, April 7, 1988
Weekly newspaper from Canadian, Texas that includes local, state and national news along with extensive advertising.
Date:
April 7, 1988
Creator:
Ezzell, Ben & Ezzell, Nancy
Object Type:
Newspaper
System:
The Portal to Texas History
Plasmas in particle accelerators: the warm-beam equilibria
For a complete set of equilibrium particle densities and temperature, the corresponding distribution functions including space charge effects are provided through solution of the inverse equilibrium problem. An accompanying orbit theory shows that the projected transverse rosette orbit can be analyzed into a circular rotation (drift) and a betatron-vortex gyration. In the presence of more general beam density profiles, the betatron vortex gyrations assume an elliptical rather than circular shape.
Date:
April 7, 1981
Creator:
Mark, J.W.K. & Smith, L.
Object Type:
Report
System:
The UNT Digital Library
[News Clip: Henry Fonda]
B-roll video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date:
April 7, 1980, 5:00 p.m.
Creator:
KXAS-TV (Television station : Fort Worth, Tex.)
Object Type:
Video
System:
The UNT Digital Library
[News Clip: NTSU Demonstrations]
B-roll video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date:
April 7, 1980, 5:00 p.m.
Creator:
KXAS-TV (Television station : Fort Worth, Tex.)
Object Type:
Video
System:
The UNT Digital Library
[News Clip: NTSU Demonstration]
Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date:
April 7, 1980, 6:00 p.m.
Creator:
KXAS-TV (Television station : Fort Worth, Tex.)
Object Type:
Video
System:
The UNT Digital Library
The Bogata News (Bogata, Tex.), Vol. 77, No. 26, Ed. 1 Thursday, April 7, 1988
Weekly newspaper from Bogata, Texas that includes local, state, and national news along with advertising.
Date:
April 7, 1988
Creator:
Nichols, Nanalee & Nichols, Thomas
Object Type:
Newspaper
System:
The Portal to Texas History
Materials at extreme conditions: ICF targets
Currently two simple theories are heavily used in laser-fusion research: the Thomas-Fermi-Dirac statistical model, and an atomic ionization model based on screened hydrogen like energy levels. Recent improvements in these theories are summarized. We show representation calculations of thermodynamic properties, ionization, x-ray emission rates and fast-ion stopping powers, and give a brief sketch of the major unresolved scientific questions.
Date:
April 7, 1980
Creator:
More, R.M.
Object Type:
Article
System:
The UNT Digital Library
Computer automation for chemistry instruments. Final report, February 1, 1980-January 31, 1981
The work performed consisted of the following: (1) development of computer aided design software for polynomial filters and Butterworth-Chebychev filter design; (2) development of algorithms for resolving peaks in spectroscopic data; and (3) interaction with LLL personnel to develop a structure for automation of surface chemistry spectroscopy. Each work phase is discussed in detail.
Date:
April 7, 1981
Creator:
Brubaker, T.A.
Object Type:
Report
System:
The UNT Digital Library
Fluid dynamics of double diffusive systems
A study of mixing processes in doubly diffusive systems is being conducted. Continuous gradients of two diffusing components (heat and salinity in our case) are being used as initial conditions, and forcing is introduced by lateral heating and surface shear. The goals of the proposed work include: (1) quantification of the effects of finite amplitude disturbances on stable, double diffusive systems, particularly with respect to lateral heating, (2) development of an improved understanding of the physical phenomena present in wind-driven shear flows in double diffusive stratified environments, (3) increasing our knowledge-base on turbulent flow in stratified environments and how to represent it, and (4) formulation of a numerical code for such flows. The work is being carried out in an experimental facility which is located in the Stanford Environmental Fluid Mechanics Laboratory, and on laboratory minicomputers and CRAY computers. In particular we are focusing on the following key issues: (1) the formation and propagation of double diffusive intrusions away from a heated wall and the effects of lateral heating on the double diffusive system; (2) the interaction between the double diffusively influenced fluxes and the turbulence induced fluxes; (3) the measurement of heat and mass fluxes; and (4) the influence …
Date:
April 7, 1989
Creator:
Koseff, J. R.
Object Type:
Report
System:
The UNT Digital Library
Isotropy of ultra-high-energy cosmic rays and multiple supernova I galactic source
Ultra-high-energy cosmic rays are usually associated with an extragalactic origin. Active galactic nuclei are an unlikely source because of photon drag. Here the possibility of supernova events are considered. The time spread of arrival of 10/sup 20/ eV protons is 100 to 400 years at 10 to 20 kpc and the angular spread is +-15 to +-30/sup 0/ depending upon the Galactic field configuration. The time spread is sufficient to include several to a dozen type I SN. This is enough events and angular spread to include the observed data. The concentration of the observed events at the galactic poles is contradictory. The flux is reasonable if the observed flux and slope at 10/sup 12/ to 10/sup 15/ eV is characteristic of the source(s) and confined at this energy for roughly 100 traversals of the Galaxy, or 3 x 10/sup 6/ years.
Date:
April 7, 1983
Creator:
Colgate, S. A.
Object Type:
Article
System:
The UNT Digital Library
Environmental and biological behaviour of plutonium and some other transuranium elements
The objectives are to summarize our knowledge of the way in which plutonium and some other transuranium elements migrate through ecosystems; to consider how the physiochemical state of these elements and the biological systems through which they pass may influence this movement; and to put into perspective the risks of serious illness in man resulting from his exposure to these elements in the environment.
Date:
April 7, 1983
Creator:
Richmond, C.R.
Object Type:
Article
System:
The UNT Digital Library
Photon damping in cosmic-ray acceleration in active galactic nuclei
The usual assumption of the acceleration of ultra high energy cosmic rays, greater than or equal to 10/sup 18/ eV in quasars, Seyfert galaxies and other active galactic nuclei is challenged on the basis of the photon interactions with the accelerated nucleons. This is similar to the effect of the black body radiation on particles > 10/sup 20/ eV for times of the age of the universe except that the photon spectrum is harder and the energy density greater by approx. = 10/sup 15/. Hence, a single traversal, radial or circumferential, of radiation whose energy density is no greater than the emitted flux will damp an ultra high energy. Hence, it is unlikely that any reasonable configuration of acceleration can void disastrous photon energy loss. A different site for ultra high energy cosmic ray acceleration must be found.
Date:
April 7, 1983
Creator:
Colgate, S. A.
Object Type:
Article
System:
The UNT Digital Library
Effects of end cell ion cyclotron fluctuations on central-cell ion confinement in the tandem mirror experiment (TMX)
The tandem mirror device (TMX) exhibits gross stability to both MHD and microinstability modes. The end-cell plasmas provide the tandem with average minimum-B stability, while the efflux of plasma from the central cell maintains the end cells (plugs) at marginal stability to loss cone modes. For some operating conditions, a residual level of plug ion cyclotron fluctuations is detected. These oscillations dominate the fluctuation frequency spectra in both the plugs and the central cell. The presence of plug ion cyclotron fluctuations in the central cell leads to resonance heating of some of the central cell ions. This heating degrades the confinement of the central cell ions; thereby increasing the amount of warm plasma stream flowing through the plugs.
Date:
April 7, 1980
Creator:
Grubb, D. P.; Casper, T. A. & Clauser, J. F.
Object Type:
Article
System:
The UNT Digital Library
High voltage, high power operation of the plasma erosion opening switch
A Plasma Erosion Opening Switch (PEOS) is used as the opening switch for a vacuum inductive storage system driven by a 1.8-MV, 1.6-TW pulsed power generator. A 135-nH vacuum inductor is current charged to approx.750 kA in 50 ns through the closed PEOS which then opens in <10 ns into an inverse ion diode load. Electrical diagnostics and nuclear activations from ions accelerated in the diode yield a peak load voltage (4.25 MV) and peak load power (2.8 TW) that are 2.4 and 1.8 times greater than ideal matched load values for the same generator pulse.
Date:
April 7, 1987
Creator:
Neri, J. M.; Boller, J. R.; Ottinger, P. F.; Weber, B. V. & Young, F. C.
Object Type:
Report
System:
The UNT Digital Library
[Letter from Jan K. Muhlert to D. Jack Davis and R. William McCarter, April 7, 1988]
A letter from Jan K. Muhlert, director of the Amon Carter Museum, to D. Jack Davis and R. William McCarter, co-directors of the project. The letter addresses the continued support of the Amon Carter towards the North Texas Regional Institute for Educators on the Visual Arts.
Date:
April 7, 1988
Creator:
Muhlert, Jan K.
Object Type:
Letter
System:
The UNT Digital Library
[Letter from Edmund P. Pillsbury to D. Jack Davis and R. William McCarter, April 7, 1988]
A letter from Edmund P. Pillsbury, Director of the Kimbell Art Museum, to D. Jack Davis and R. William McCarter, co-directors of the project. The letter references a previous exchange between the group and addresses the continued support of the North Texas Regional Institute for Educators on the Visual Arts project.
Date:
April 7, 1988
Creator:
Pillsbury, Edmund P.
Object Type:
Letter
System:
The UNT Digital Library
[Letter from Dr. Anne R. Bromberg to D. Jack Davis and R. William McCarter, April 7, 1988]
A letter from Dr. Anne R. Bromberg, Director of Education at the DMA, to Drs. D. Jack Davis and R. William McCarter, co-directors of the project. The letter addresses the continued support to the proposal of a North Texas Regional Institute for Educators in the Visual Arts and its DBAE concept.
Date:
April 7, 1988
Creator:
Bromberg, Dr. Anne R.
Object Type:
Letter
System:
The UNT Digital Library