Impulsive ion acceleration in earth's outer magnetosphere (open access)

Impulsive ion acceleration in earth's outer magnetosphere

Considerable observational evidence is found that ions are accelerated to high energies in the outer magnetosphere during geomagnetic disturbances. The acceleration often appears to be quite impulsive causing temporally brief (10's of seconds), very intense bursts of ions in the distant plasma sheet as well as in the near-tail region. These ion bursts extend in energy from 10's of keV to over 1 MeV and are closely associated with substorm expansive phase onsets. Although the very energetic ions are not of dominant importance for magnetotail plasma dynamics, they serve as an important tracer population. Their absolute intensity and brief temporal appearance bespeaks a strong and rapid acceleration process in the near-tail, very probably involving large induced electric fields substantially greater than those associated with cross-tail potential drops. Subsequent to their impulsive acceleration, these ions are injected into the outer trapping regions forming ion ''drift echo'' events, as well as streaming tailward away from their acceleration site in the near-earth plasma sheet. Most auroral ion acceleration processes occur (or are greatly enhanced) during the time that these global magnetospheric events are occurring in the magnetotail. A qualitative model relating energetic ion populations to near-tail magnetic reconnection at substorm onset followed by …
Date: January 1, 1985
Creator: Baker, D.N. & Belian, R.D.
Object Type: Article
System: The UNT Digital Library
The limited streamer tubes system for the SLD warm iron calorimeter (open access)

The limited streamer tubes system for the SLD warm iron calorimeter

The SLD detector at the Stanford Linear Accelerator Center is a general purpose device for studying e{sup +}{epsilon}{sup {minus}} interaction at the Z{sup 0}. The SLD calorimeter system consists of two parts: a lead Liquid Argon Calorimeter (LAC) with both electromagnetic (22 radiation lengths) and hadronic sections (2.8 absorption lengths) housed inside the coil, and the Warm Ion limited streamer tubes Calorimeter (WIC) outside the coil which uses as radiator the iron of the flux return for the magnetic field. The WIC completes the measurement of the hadronic shower energy ({approximately}85% on average is contained in the LAC) and it provides identification and tracking for muons over 99% of the solid angle. In this note we report on the construction, test and commissioning of such a large system.
Date: January 1, 1992
Creator: Benvenuti, A. C.; Camanzi, B.; Piemontese, L.; Zucchelli, P.; Calcaterra, A.; De Sangro, R. et al.
Object Type: Article
System: The UNT Digital Library
Quantitative analysis of the hydrothermal system in Lassen Volcanic National Park and Lassen Known Geothermal Resource Area (open access)

Quantitative analysis of the hydrothermal system in Lassen Volcanic National Park and Lassen Known Geothermal Resource Area

The Lassen hydrothermal system is in the southern Cascade Range, approximately 70 kilometers east-southeast of Redding, California. The conceptual model of the Lassen system is termed a liquid-dominated hydrothermal system with a parasitic vapor-dominated zone. The essential feature of this model is that steam and steam-heated discharge at relatively high elevations in Lassen Volcanic National Park (LVNP) and liquid discharge with high chloride concentrations at relatively low elevations outside LVNP in the Lassen Known Geothermal Resource Area (KGRA) are both fed by an upflow of high-enthalpy, two-phase fluid within the Park. Liquid flows laterally away from the upflow area towards the areas of high-chloride discharge, and steam rises through a vapor-dominated zone to feed the steam and steam-heated features. The geometric model corresponds to an areally restricted flow regime that connects the Bumpass Hell area in LVNP with regions of chloride hot springs in the Mill Creek canyon in the KGRA south of LVNP. Simulations of thermal fluid withdrawal in the Mill Creek Canyon were carried out in order to determine the effects of such withdrawal on portions of the hydrothermal system within the Park. 19 refs., 17 figs., 4 tabs.
Date: January 1, 1984
Creator: Sorey, M.L. & Ingebritsen, S.E.
Object Type: Report
System: The UNT Digital Library
Relativistic effects in the atomic and nuclear few-body problems (open access)

Relativistic effects in the atomic and nuclear few-body problems

Relativistic effects in the atomic and nuclear few-body systems are classified and discussed with the emphasis on electromagnetic transitions. The size of relativistic corrections, calculational techniques and ambiguities, and comparison of theory and experiment are considered. 8 figures.
Date: January 1, 1980
Creator: Friar, J.L.
Object Type: Article
System: The UNT Digital Library
Western Gas Sands Project. Status report, 1 May-31 May, 1980 (open access)

Western Gas Sands Project. Status report, 1 May-31 May, 1980

This report summarizes the progress of the government-sponsored project directed towards increasing gas production from the low permeability gas sands of the western United States. The planning activities for the multi-well experiment continued in May. Bartlesville Energy Technology Center continued formation evaluation and reservoir simulation studies. Lawrence Livermore Laboratory continued calculations of fracturing near interfaces. Los Alamos Scientific Laboratory focused work on the permanent magnet system for NMR logging. Results of the 3-D Seismic Reflection Survey were presented by Sandia Laboratories. Production and injection experiments continued for the Colorado Interstate Gas Company Miller No. 1 and Sprague No. 1 wells. The DOE Well Test Facility was transported to Las Vegas for repairs and modifications. In situ testing continued at the Nevada Test Site for the Sandia Mineback program.
Date: January 1, 1980
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Microcrystalline silicon growth for heterojunction solar cells. Second quarterly report, 1 April 1983-30 June 1983 (open access)

Microcrystalline silicon growth for heterojunction solar cells. Second quarterly report, 1 April 1983-30 June 1983

In this reporting period, a single source of evaporation with B mixed with highly doped Si was used instead of the co-evaporation of separate Si and B sources. The purpose was to reduce possible carbon contamination. The results of both the heterojunction or heteroface structures, however, were similar to last quarter when evaporation was used. The best Voc of the heterojunction was about 460mV and no improvement in Voc in the heteroface structure, was observed; slight Voc degradation occurred. A study of the p m-Si/p c-Si structure showed a negative Voc in many cases. The highest /sup 0/C voltage was up to -150mV. This indicated that the interface properties between the two materials are such that instead of repelling minority carriers from the substrate carrier, collection actually occurred. This structure defeated the purpose, but it might also mean that n-type m-Si could be beneficial and should be included in future study. Another study of cells made in the part of substrates not covered by m-Si resulted in performance lower than the controls. This indicated possible substrate degradation in the process, the extent of which will be studied in the future.
Date: January 1, 1983
Creator: Iles, P. A.; Leung, D. C. & Fang, P. H.
Object Type: Report
System: The UNT Digital Library
Measurements of Non-Leptonic Weak Decays of Lambda Hypernuclei (open access)

Measurements of Non-Leptonic Weak Decays of Lambda Hypernuclei

Aspects of recent measurements of the mesonic and non-mesonic partial decay rates of {sub {Lambda}}{sup 5}He, and {sub {Lambda}}{sup 12}C are discussed. We comment on what the experiments tell us about the spin-isospin structure of {Delta}S=1 weak interaction in the nuclear environment. 14 refs., 1 fig.
Date: January 1, 1991
Creator: Schumacher, Reinhard A.
Object Type: Article
System: The UNT Digital Library
De-entrainment on vertical elements in air droplet cross flow. [PWR] (open access)

De-entrainment on vertical elements in air droplet cross flow. [PWR]

De-entrainment phenomena on vertical elements in air-water droplet cross flow are generated using a horizontal array of water spray nozzles and a draft-induced wind tunnel. These conditions are used to obtain experimental values of the de-entrainment efficiency of isolated elements (25.4-, 63.5-, and 101.6-mm-diam cylinders and a 76.2-mm-square tube), and of an array of 101.6-mm-diam cylinders. A flow model is developed that extrapolates the de-entrainment efficiency of isolated elements through the use of a correlation for the interference effect to predict the efficiency of large arrays of similar elements. This simple model is shown to provide a good prediction of the de-entrainment efficiency of arrays in terms of the efficiency of an isolated element.
Date: January 1, 1980
Creator: Dallman, J.C. & Kirchner, W.L.
Object Type: Article
System: The UNT Digital Library
Electrochemistry of Thiobacillus ferrooxidans reactions with pyrite (open access)

Electrochemistry of Thiobacillus ferrooxidans reactions with pyrite

The objective of this project is to provide the fundamental information on the mechanisms of bacterial leaching of pyrite. The knowledge of how bacterial leaching of pyrite functions is essential for design and development of a technology for coal cleaning with bacteria. The features of major electrochemical techniques will be examined to find out if any of them can provide a diagnostic information on the mechanisms of related reactions.
Date: January 1, 1992
Creator: Pesic, B.
Object Type: Report
System: The UNT Digital Library
RADIOACTIVE WASTE LOCATION VIA INFRARED SCANNING TECHNIQUES. (open access)

RADIOACTIVE WASTE LOCATION VIA INFRARED SCANNING TECHNIQUES.

None
Date: January 1, 1968
Creator: Jensen, J D
Object Type: Report
System: The UNT Digital Library
Defects in metal crystals. Progress report, May 1, 1973--April 30, 1974 (open access)

Defects in metal crystals. Progress report, May 1, 1973--April 30, 1974

Progress was made in the following areas: FIM (field ion microscopy) studies of defects in W irradiated with W ions or electrons; FIM studies of Au irradiated with Au or Xe ions; FIM and electrical resistivity study of vacancy defects in quenched W; FIM studies of dilute Pt alloys; measurement of the range of focused replacement sequences in Au; investigation of grain boundary strtucture (using Au); FIM observation of dissociated screw dislocations in Mo; calculation of properties of point defects in metals; and atom probe FIM. (auth)
Date: January 1, 1974
Creator: Balluffi, R.W. & Seidman, D.N.
Object Type: Report
System: The UNT Digital Library
Observations on the Effect of Selected Organic Materials on the Usable Potential Ranges of the Glassy Carbon, Pyrolytic Graphite, and Platinum Electrodes. (open access)
Catalyst and process development for hydrogen preparation from future fuel cell feedstocks. Quarterly progress report, October 1, 1979-December 31, 1979. [Pt/Rh, Ni/Rh, Ni/Pt/Rh, Ni, Ni/Ru, Ni/Pt, Ni/Co] (open access)

Catalyst and process development for hydrogen preparation from future fuel cell feedstocks. Quarterly progress report, October 1, 1979-December 31, 1979. [Pt/Rh, Ni/Rh, Ni/Pt/Rh, Ni, Ni/Ru, Ni/Pt, Ni/Co]

Twelve steam reforming catalysts were evaluated using an autothermal reforming screening unit. Duplicate tests were run with two samples to determine test variability. The samples tested contained either base metals, precious metals, or combinations of base and precious metals. The test was capable of distinguishing among samples where gross variations in composition are the main factor; for example, catalysts containing 2% by weight precious metals are more active than catalysts containing 15% by weight nickel. The results show a decrease in hydrocarbon breakthrough as the weight of nickel charged to the constant volume reactor increases. A commercial nickel catalyst, G90C, appears slightly better than some Engelhard prepared samples of equal nickel concentrations due to the higher density of G90C. Visual observation of the used catalysts show that samples containing only precious metals (Pt/Rh) did not coke during the run. The samples containing only base metals (nickel, cobalt) were coked and were magnetic. Samples containing 14.5% nickel by weight with 0.5% precious metals by weight added were not coked, were not magnetic, and had a blue colored core as compared to the black core of the virgin samples. Some speculation about deactivation mechanisms based on these observations are made.
Date: January 1, 1980
Creator: Yarrington, R M; Feins, I R; Hwang, H S & Mayer, C P
Object Type: Report
System: The UNT Digital Library
Laser-plasma interaction experiments at laser wavelengths of 1. 064. mu. m, 0. 532. mu. m, and 0. 355. mu. m (open access)

Laser-plasma interaction experiments at laser wavelengths of 1. 064. mu. m, 0. 532. mu. m, and 0. 355. mu. m

The effect of laser wavelength on laser-plasma coupling is one of the critical issues facing the laser driven inertial confinement community. The advantages of using lasers with output wavelength less than 1 ..mu..m, such as enhanced absorption and hydrodynamic efficiency, reduction in parametric instabilities and corresponding suprathermal electron generation, have long been predicted theoretically.
Date: January 1, 1982
Creator: Campbell, E. M.; Mead, W. C. & Turner, R. E.
Object Type: Article
System: The UNT Digital Library
Coordination/management tasks for the IEA and CCMS solar heating and cooling programs (open access)

Coordination/management tasks for the IEA and CCMS solar heating and cooling programs

None
Date: January 1, 1980
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Large Radioisotope Heat Source Capsule (LRHSC). Sixth Quarterly Progress Report, October--December 1968. (open access)

Large Radioisotope Heat Source Capsule (LRHSC). Sixth Quarterly Progress Report, October--December 1968.

None
Date: January 1, 1969
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Growth regulation by macrophages (open access)

Growth regulation by macrophages

The evidence reviewed here indicates that macrophages, either acting alone or in concert with other cells, influence the proliferation of multiple types of cells. Most of the data indicate that these effects are mediated by soluble macrophage-elaborated products (probably proteins) although the role of direct cell-to-cell contacts cannot be ruled out in all cases. A degree of success has been achieved on the biochemical characterization of these factors, due mainly to their low specific activity in conditioned medium and the lack of rapid, specific assays. Understanding the growth-regulating potential of macrophages is an important and needed area of research.
Date: January 1, 1982
Creator: Wharton, W.; Walker, E. & Stewart, C.C.
Object Type: Article
System: The UNT Digital Library
Removal of $sup 137$Cs From Alkaline Condensate Wastes (open access)

Removal of $sup 137$Cs From Alkaline Condensate Wastes

None
Date: January 1, 1968
Creator: Mercer, B. W.; Ames, L. L. & Parkhurst, R. G.
Object Type: Report
System: The UNT Digital Library
Diskless LSI-11 systems (open access)

Diskless LSI-11 systems

Programs for dedicated LSI-11 based systems can easily be stored in ROM instead of floppy disks, yet execute the same as disk-stored programs. Two sample systems are described.
Date: January 1, 1982
Creator: Ford, W. & Shirk, D. G.
Object Type: Article
System: The UNT Digital Library
AEC FUELS AND MATERIALS DEVELOPMENT PROGRAM. Seventh Annual Report. (open access)

AEC FUELS AND MATERIALS DEVELOPMENT PROGRAM. Seventh Annual Report.

This report is the seventh annual report of the unclassified portion of the Fuels and Materials Development Programs being conducted by the General Electric Company's Nuclear Materials and Propulsion Operation under Contract AT(40-1)-2847, issued by the Fuels and Materials Branch, Division of Reactor Development and Technology, of the Atomic Energy Commission. This report covers the period from January 31, 1967 to January 31, 1968, and thus also serves as the quarterly progress report for the final quarter of the year.
Date: January 1, 1968
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Sintering of polycrystalline ionic conductors:. beta. ''-Al/sub 2/O/sub 3/ and NASICON (open access)

Sintering of polycrystalline ionic conductors:. beta. ''-Al/sub 2/O/sub 3/ and NASICON

The densification kinetics for both ..beta..''-alumina and NASICON are dramatically different. ..beta..''-Alumina sinters by a reactive liquid process whereas NASICON densifies by a solid state method. More importantly, a qualitative examination of particle and agglomerate distributions, phase composition, linear shrinkage analysis, and heating rate effects can result in a concise determination of sintering processes without recourse to more quantitative techniques. Such a simple procedural method should be a basis for any beginning investigative study into the densification mechanism of new multicomponent ceramic materials.
Date: January 1, 1979
Creator: McEntire, B. J.; Miller, G. R. & Gordon, R. S.
Object Type: Article
System: The UNT Digital Library
SURVEY OF REACTOR FACILITIES FOR PRESSURE TUBE IRRADIATION. (open access)

SURVEY OF REACTOR FACILITIES FOR PRESSURE TUBE IRRADIATION.

None
Date: January 1, 1968
Creator: Ard, P. A.; Heck, E. N. & McJilton, C. H.
Object Type: Report
System: The UNT Digital Library
Severe accident core heatup transients in modular high temperature gas-cooled reactors without operating Reactor Cavity Cooling Systems (open access)

Severe accident core heatup transients in modular high temperature gas-cooled reactors without operating Reactor Cavity Cooling Systems

The ultimate decay heat removal system for the current Modular High Temperature Gas-Cooled reactors is a completely passive natural convection air cooling loop. This paper considers an extremely remote accident scenario, where even this passive system fails, and heat rejection is only via a layer of thermal insulation to the reactor silo structure and the surrounding soil. The results show that even in this case the peak fuel temperatures remain well within safe limits. However, vessel and concrete temperatures can - under extreme circumstances and after several weeks - reach temperature levels at which structural failure becomes possible.
Date: January 1, 1988
Creator: Kroeger, P. G.
Object Type: Article
System: The UNT Digital Library
The microscopic world: A demonstration of electron microscopy for younger students (open access)

The microscopic world: A demonstration of electron microscopy for younger students

None
Date: January 1, 1991
Creator: Horton, L. L.
Object Type: Article
System: The UNT Digital Library