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Abilene Philharmonic Playbill: February 20-March 13, 1999
Program for an Abilene Philharmonic concert that ran from February 20th to March 13th during the 49th season. It includes information about the pieces performed, artists and musicians, and advertising from local companies.
Date:
February 1999
Creator:
Abilene Philharmonic
Object Type:
Pamphlet
System:
The Portal to Texas History
Abilene Philharmonic Playbill: April 10-May 1, 1999
Program for an Abilene Philharmonic concert that ran from April 10th to May 1st (Classical IV and Classical V) during the 49th season. It includes information about the pieces performed, artists and musicians, and advertising from local companies.
Date:
April 1999
Creator:
Abilene Philharmonic
Object Type:
Pamphlet
System:
The Portal to Texas History
Abilene Philharmonic Playbill: September 25-October 30, 1999
Program for an Abilene Philharmonic concert that ran from September 25th to October 30th during the 50th season. It includes information about the pieces performed, artists and musicians, and advertising from local companies.
Date:
September 1999
Creator:
Abilene Philharmonic
Object Type:
Pamphlet
System:
The Portal to Texas History
AmBe Waste Minimization Activities Annual Report
The CST-11 objective for the Radioactive Source Recovery Project is to evaluate a nitric acid-based flowsheet and alternatives for dissolution, separation, and recovery of americium from AmBe neutron source materials returned from private and governmental institutions. Specific tasks performed during FY97 and FY98 included the experimental investigation of material dissolution rate and efficiency as a function of time and temperature for nitric acid as compared to hydrochloric acid. Alkaline dissolution reaction conditions using sodium hydroxide and ammonium bifluoride were also investigated. In both the acidic and alkaline dissolution conditions, the objective was to effect an initial separation of the americium from the beryllium or vice versa. The process solution and remaining solids should also be amenable to further processing and purification schemes. This work was performed on actual AmBe neutron source material in order to demonstrate the feasibility of {sup 241}Am purification from dismantled neutron sources.
Date:
May 1, 1999
Creator:
Abney, Kent D.; Svitra, Zita V. & Cisneros, Michael R.
Object Type:
Report
System:
The UNT Digital Library
Computational Analysis of Heat Flow Calorimeters
None
Date:
November 28, 1999
Creator:
Aboagye, Steve A. & Ball, Kenneth S.
Object Type:
Article
System:
The UNT Digital Library
Calorimeter Preamplifier Hybrid Circuit Test Jig
There are two ways in which the testing may be initiated, remotely or locally. If the remote operation is desired, an external TTL level signal must be provided to the test jig with the remotellocal switch on the side of the test jig switched to remote. A logic high will initiate the test. A logic low will terminate the test. In the event that an external signal is connected to the test jig while local operation occurs, the local control takes precedence over remote control. Once a DVT has been locked in the ZIF socket and the DIP switches are selected, the Push-to-Test button may be depressed. Momentarily depressing the button will initiate a test with a minimum 400 ms duration. At the same time a PBCLOCK and PBLATCH pulses will be initiated and the power rails +12V, +8V, and -6V will be ramped to full voltage. The time at which the power rails reach the full voltage is about 13 ms and it is synchronized with bypass capacitors placed on COMP input of U20 and U22 and on the output of U23 voltage regulators. The voltage rails are supplied to a {+-}10% window comparator. A red LED indicates the …
Date:
April 19, 1999
Creator:
Abraham, Benjamin M.
Object Type:
Report
System:
The UNT Digital Library
Corrosion behavior of stainless steel-zirconium alloy waste forms.
Stainless steel-zirconium (SS-Zr) alloys are being considered as waste forms for the disposal of metallic waste generated during the electrometallurgical treatment of spent nuclear fuel. The baseline waste form for spent fuels from the EBR-II reactor is a stainless steel-15 wt.% zirconium (SS-15Zr) alloy. This article briefly reviews the microstructure of various SS-Zr waste form alloys and presents results of immersion corrosion and electrochemical corrosion tests performed on these alloys. The electrochemical tests show that the corrosion behavior of SS-Zr alloys is comparable to those of other alloys being considered for the Yucca Mountain geologic repository. The immersion tests demonstrate that the SS-Zr alloys are resistant to selective leaching of fission product elements and, hence, suitable as candidates for high-level nuclear waste forms.
Date:
January 13, 1999
Creator:
Abraham, D. P.
Object Type:
Article
System:
The UNT Digital Library
Phase stability of laves intermetallics in stainless steel-zirconium alloys.
Phase transformations occurring in a stainless steel-15 wt% zirconium (SS-15Zr) alloy were studied by in situ neutron diffraction. Neutron diffraction patterns as a function of time were obtained on alloys that were held at various elevated temperatures (1084-1275 C). As-cast SS-15Zr alloys contain ferrite, austenite, ZrFe{sub 2}-type Laves polytypes C36 and C15, and small amounts of a Fe{sub 23}Zr{sub 6}-type intermetallic. Annealing at high temperatures resulted in an increase of the Fe{sub 23}Zr{sub 6}, intermetallic content. The C15 Laves polytype is the equilibrium phase for T {le} 1230 C; C36 is the stable polytype at higher temperatures ({approximately}1275 C). Phase changes were slow for temperatures <1100 C.These findings have important implications for use of the SS-15Zr alloy as a nuclear waste form.
Date:
April 8, 1999
Creator:
Abraham, D. P.
Object Type:
Article
System:
The UNT Digital Library
Electrochemical corrosion testing of metal waste forms
Electrochemical corrosion tests have been conducted on simulated stainless steel-zirconium (SS-Zr) metal waste form (MWF) samples. The uniform aqueous corrosion behavior of the samples in various test solutions was measured by the polarization resistance technique. The data show that the MWF corrosion rates are very low in groundwaters representative of the proposed Yucca Mountain repository. Galvanic corrosion measurements were also conducted on MWF samples that were coupled to an alloy that has been proposed for the inner lining of the high-level nuclear waste container. The experiments show that the steady-state galvanic corrosion currents are small. Galvanic corrosion will, hence, not be an important mechanism of radionuclide release from the MWF alloys.
Date:
December 14, 1999
Creator:
Abraham, D. P.; Peterson, J. J.; Katyal, H. K.; Keiser, D. D. & Hilton, B. A.
Object Type:
Article
System:
The UNT Digital Library
The Solvation Properties of the Aliphatic Alcohols
Article on the solvation properties of the aliphatic alcohols.
Date:
1999
Creator:
Abraham, M. H. (Michael H.); Le, Joelle & Acree, William E. (William Eugene)
Object Type:
Article
System:
The UNT Digital Library
Natural Analogues of Nuclear Waste Glass Corrosion.
This report reviews and summarizes studies performed to characterize the products and processes involved in the corrosion of natural glasses. Studies are also reviewed and evaluated on how well the corrosion of natural glasses in natural environments serves as an analogue for the corrosion of high-level radioactive waste glasses in an engineered geologic disposal system. A wide range of natural and experimental corrosion studies has been performed on three major groups of natural glasses: tektite, obsidian, and basalt. Studies of the corrosion of natural glass attempt to characterize both the nature of alteration products and the reaction kinetics. Information available on natural glass was then compared to corresponding information on the corrosion of nuclear waste glasses, specifically to resolve two key questions: (1) whether one or more natural glasses behave similarly to nuclear waste glasses in laboratory tests, and (2) how these similarities can be used to support projections of the long-term corrosion of nuclear waste glasses. The corrosion behavior of basaltic glasses was most similar to that of nuclear waste glasses, but the corrosion of tektite and obsidian glasses involves certain processes that also occur during the corrosion of nuclear waste glasses. The reactions and processes that control basalt …
Date:
January 6, 1999
Creator:
Abrajano, T. A., Jr.; Ebert, W. L. & Luo, J. S.
Object Type:
Report
System:
The UNT Digital Library
Stable isotope investigations of chlorinated aliphatic hydrocarbons.
Stable isotope ratio measurements for carbon (C) and chlorine (Cl) can be used to elucidate the processes affecting transformation and transportation of chlorinated aliphatic hydrocarbons (CAHs) in the environment. Methods recently developed in our laboratory for isotopic analysis of CAHs have been applied to laboratory measurements of the kinetic isotope effects associated with aerobic degradation of dichloromethane (DCM) and with both anaerobic and aerobic cometabolic degradation of trichlomethene (TCE) in batch and column microbial cultures. These experimental determinations of fractionation factors are crucial for understanding the behavior of CAHs in complex natural systems, where the extent of biotransformation can be masked by dispersion and volatilization. We have also performed laboratory investigations of kinetic isotope effects accompanying evaporation of CAHs, as well as field investigations of natural attenuation and in situ remediation of CAHs in a number of contaminated shallow aquifers at sites operated by the federal government and the private sector.
Date:
June 1, 1999
Creator:
Abrajano, T.; Heraty, L. J.; Holt, B. D.; Huang, L. & Sturchio, N. C.
Object Type:
Article
System:
The UNT Digital Library
Low Speed Carbon Deposition Process for Hermetic Optical Fibers
For optical fibers used in adverse environments, a carbon coating is frequently deposited on the fiber surface to prevent water and hydrogen ingression that lead respectively to strength degradation through fatigue and hydrogen-induced attenuation. The deposition of a hermetic carbon coating onto an optical fiber during the draw process holds a particular challenge when thermally-cured specialty coatings are subsequently applied because of the slower drawing rate. In this paper, we report on our efforts to improve the low-speed carbon deposition process by altering the composition and concentration of hydrocarbon precursor gases. The resulting carbon layers have been analyzed for electrical resistance, Raman spectra, coating thickness, and surface roughness, then compared to strength data and dynamic fatigue behavior.
Date:
September 29, 1999
Creator:
Abramczyk, Jaroslaw; Arthur, Sara E.; Tallant, David R.; Hikansson, Adam S.; Lindholm, Eric A. & Lo, Jie
Object Type:
Article
System:
The UNT Digital Library
Focused Ion Beam Induced Effects on MOS Transistor Parameters
We report on recent studies of the effects of 50 keV focused ion beam (FIB) exposure on MOS transistors. We demonstrate that the changes in value of transistor parameters (such as threshold voltage, V{sub t}) are essentially the same for exposure to a Ga+ ion beam at 30 and 50 keV under the same exposure conditions. We characterize the effects of FIB exposure on test transistors fabricated in both 0.5 {micro}m and 0.225 {micro}m technologies from two different vendors. We report on the effectiveness of overlying metal layers in screening MOS transistors from FIB-induced damage and examine the importance of ion dose rate and the physical dimensions of the exposed area.
Date:
July 28, 1999
Creator:
Abramo, Marsha T.; Antoniou, Nicholas; Campbell, Ann N.; Fleetwood, Daniel M.; Hembree, Charles E.; Jessing, Jeffrey R. et al.
Object Type:
Article
System:
The UNT Digital Library
Field emission from carbon films deposited by VHF CVD on difference substrates
As previously demonstrated, non-diamond carbon (NDC) films deposited at low temperatures 200-300 C on silicon tips reduced the threshold of field emission. In this paper we will present the results of the study of field emission from flat NDC films prepared by VHF CVD. Emission measurements were performed in a diode configuration at approximately 10{sup {minus}10} Torr. NDC films were deposited on ceramic and on c-Si substrates sputter coated with layers of Ti, Cu, Ni and Pt. The back contact material influences the emission characteristics but not as a direct correlation to work function. A model of field emission from metal-NDC film structures will be discussed.
Date:
April 1, 1999
Creator:
Abramov, A A; Andronov, A N; Felter, T E; Ioffe, A F; Kosarev, A I; Shotov, M V et al.
Object Type:
Article
System:
The UNT Digital Library
U.S./Russian cooperative efforts to enhance nuclear MPC&A at VNIITF, (Chelyabinsk-70)
The work described here is part of an effort called the Nuclear Materials Protection, Control, and Accounting (MPC&A) Program, a cooperative program between the US Department of Eenrgy (DOE) and Russia's Ministry of Atomic Energy (MinAtom). The objective of the program is to reduce the risk of nuclear proliferation by strengthening MPC&A systems at Russian nuclear Facilities. This paper describes that portion of the MPC&A program that is directed specifically to the needs of the All Russian Scientific Research Institute of Technical Physics (VNIITF), also called Chelyabinsk-70. A major MPC&A milestone was met at VNIITF when the MPC&A improvements were commissioned at the Pulse Research Reactor Facility in May of this year.
Date:
April 20, 1999
Creator:
Abramson, B.; Apt, K.; Blasy, J.; Bukin, D.; Churikov, Y.; Curtis, D. et al.
Object Type:
Article
System:
The UNT Digital Library
Oxidation of K-West Basin Spent Nuclear Fuel in Moist Helium Atmosphere
None
Date:
June 15, 1999
Creator:
Abrefah, J. & Sell, R. L.
Object Type:
Report
System:
The UNT Digital Library
Analysis of Ignition Testing on K-West Basin Fuel
Approximately 2100 metric tons of spent nuclear fuel (SNF) discharged from the N-Reactor have been stored underwater at the K-Basins in the 100 Area of the Hanford Site. The spent fuel has been stored in the K-East Basin since 1975 and in the K-West Basin since 1981. Some of the SNF elements in these basins have corroded because of various breaches in the Zircaloy cladding that occurred during fuel discharge operations and/or subsequent handling and storage in the basins. Consequently, radioactive material in the fuel has been released into the basin water, and water has leaked from the K-East Basin into the soil below. To protect the Columbia River, which is only 380 m from the basins, the SNF is scheduled to be removed and transported for interim dry storage in the 200 East Area, in the central portion of the Site. However, before being shipped, the corroded fuel elements will be loaded into Multi-Canister OverPacks and conditioned. The conditioning process will be selected based on the Integrated Process Strategy (IPS) (WHC 1995), which was prepared on the basis of the dry storage concept developed by the Independent Technical Assessment (ITA) team (ITA 1994).
Date:
August 10, 1999
Creator:
Abrefah, J.; Huang, F.H.; Gerry, W.M.; Gray, W.J.; Marschman, S.C. & Thornton, T.A.
Object Type:
Report
System:
The UNT Digital Library
Analysis of Ignition Testing on K-West Basin Fuel
Ignition tests and analyses of damage/corroded N-Reactor spent nuclear fuel (SNF) were performed by Pacific Northwest National Laboratory as part of a series of studies on the deteriorating spent fuel in the Hanford K-Basins. The ignition temperature tests were conducted to assess tie pyrophoric properties of selected spent fuel elements from K-West Basin. The objective of these tests was to determine pyrophoric characteristics of samples cut from both damaged and undamaged regions of fhel elements. Furnace ignition tests were also petiormed on samples subjected to the conditioning process proposed by the Independent Technical Assessment and the Integrated Process Strategy to establish any significant effect on the SNF pyrophoric pefiormance parameters. Part of the analysis of the ignition data in this report was petiormed by FIuor Daniel Northwest. One of the safety issues being evaluated is the possibility of a fiel ignition during processing, handling, and transportation to the interim storage facility.
Date:
August 10, 1999
Creator:
Abrefah, John; Huang, Fan-Hsiung F.; Gerry, William M.; Gray, Walter J.; Marschman, Steven C. & Thornton, Thomas A.
Object Type:
Report
System:
The UNT Digital Library
Theory of high-T{sub c} cuprates based on experimental evidence.
A model of superconductivity in layered high-temperature superconducting cuprates is proposed, based on the extended saddle point singularities in the electron spectrum, weak screening of the Coulomb interaction and phonon-mediated interaction between electrons plus a small short-range repulsion of Hund's, or spin-fluctuation, origin. This permits to explain the large values of T{sub c}, features of the isotope effect on oxygen and copper, the existence of two types of the order parameter, the peak in the inelastic neutron scattering, the positive curvature of the upper critical field, as function of temperature etc.
Date:
August 17, 1999
Creator:
Abrikosov, A. A.
Object Type:
Article
System:
The UNT Digital Library
Theory of high-{Tc} superconducting cuprates based on experimental evidence
A model of superconductivity in layered high-temperature superconducting cuprates is proposed, based on the extended saddle point singularities in the electron spectrum, weak screening of the Coulomb interaction and phonon-mediated interaction between electrons plus a small short-range repulsion of Hund's, or spin-fluctuation, origin. This permits to explain the large values of {Tc}, features of the isotope effect on oxygen and copper, the existence of two types of the order parameter, the peak in the inelastic neutron scattering, the positive curvature of the upper critical field, as function of temperature etc.
Date:
December 10, 1999
Creator:
Abrikosov, A. A.
Object Type:
Article
System:
The UNT Digital Library
The Migration and Entrapment of DNAPLs in Physically and Chemically Heterogeneous Porous Media
Dense nonaqueous phase liquids (DNAPLs) are common subsurface contaminants at many Department of Energy (DOE) hazardous waste sites. The migration and entrapment of DNAPLs at these sites is greatly influenced by subsurface heterogeneity, both physical and chemical. Unfortunately, the physics of DNAPL flow in chemically heterogeneous systems is poorly understood and, hence, multiphase flow simulators typically assume that subsurface soils are completely water-wet (chemically homogeneous). The primary objective of this research is to improve our understanding of and ability to simulate the influence of subsurface chemical heterogeneities on DNAPL flow and entrapment in the saturated zone. Laboratory and numerical investigations are being conducted for a matrix of organic contaminants and porous media encompassing a range of wettability characteristics. Specific project objectives include: (1) quantification of system wettability and interfacial tensions; (2) determination of hydraulic property relations; (3) investigation of DNAPL infiltration behavior in two-dimensional systems; (4) modification of a continuum based multiphase flow simulator to account for coupled physical and chemical heterogeneity; and (5) exploration of the migration of DNAPLs and the development of innovative remediation schemes under heterogeneous conditions using this model.
Date:
June 1, 1999
Creator:
Abriola, Linda M.; Demond, Avery H. & Glass, Robert
Object Type:
Report
System:
The UNT Digital Library
Changes in Gas Bubble Disease Signs for Migrating Juvenile Salmonids Experimentally Exposed to Supersaturated Gasses, 1996-1997 Progress Report.
This study was designed to answer the question of whether gas bubble disease (GBD) signs change as a result of the hydrostatic conditions juvenile salmonids encounter when they enter the turbine intake of hydroelectric projects during their downstream migration.
Date:
March 1, 1999
Creator:
Absolon, Randall F.
Object Type:
Report
System:
The UNT Digital Library
Angular quadratures for improved transport computations
This paper introduces new octant-range, composite-type Gauss and mid-point rule angular quadrature formulas for neutron and photon transport computations. A generalization to octant-range quadratures is also introduced in order to allow for discontinuities at material interfaces for two- and three-dimensional transport problems which can be modeled with 60-degree triangular or hexagonal mesh subdivisions in the x-y plane.
Date:
July 22, 1999
Creator:
Abu-Shumays, I.K.
Object Type:
Article
System:
The UNT Digital Library