U N T Established 1890 U N T
University Libraries

Digital Collections

Access

Resource Type

Partner

Collection

Serial/Series Title

Degree Department

Degree Discipline

Degree Level

Country

States

Counties

Decade

Year

Month

Day

Language

270,565 Matching Results

Start Over Access Open Access Day 1st Language English

Results open in a new window/tab.

prev Results: 49 - 72 of 270,565 next
Best Match Title Creator Date Created (Newest) Date Created (Oldest) Date Added (Newest) Date Added (Oldest)
Boron reclamation (open access)

Boron reclamation

A process to recover high purity /sup 10/B enriched crystalline boron powder from a polymeric matrix was developed on a laboratory basis and ultimately scaled up to production capacity. The process is based on controlled pyrolysis of boron-filled scrap followed by an acid leach and dry sieving operation to return the powder to the required purity and particle size specifications. Typically, the recovery rate of the crystalline powder is in excess of 98.5 percent, and some of the remaining boron is recovered in the form of boric acid. The minimum purity requirement of the recovered product is 98.6 percent total boron.
Date: July 1, 1980
Creator: Smith, R. M.
Object Type: Report
System: The UNT Digital Library
Proceedings of the LAMPF workshop on physics with polarized nuclear targets (open access)

Proceedings of the LAMPF workshop on physics with polarized nuclear targets

Topics of discussion included static and dynamic methods for polarizing nuclei, proton and pion nucleus scattering experiments, and possible future experiments at LAMPF. Separate abstracts were prepared for 11 papers in this report. (DWL)
Date: August 1, 1986
Creator: Burleson, G.; Gibbs, W.; Hoffmann, G.; Jarmer, J. J. & Tanaka, N. (eds.)
Object Type: Article
System: The UNT Digital Library
ETRANS: an energy transport system optimization code for distributed networks of solar collectors (open access)

ETRANS: an energy transport system optimization code for distributed networks of solar collectors

The optimization code ETRANS was developed at the Pacific Northwest Laboratory to design and estimate the costs associated with energy transport systems for distributed fields of solar collectors. The code uses frequently cited layouts for dish and trough collectors and optimizes them on a section-by-section basis. The optimal section design is that combination of pipe diameter and insulation thickness that yields the minimum annualized system-resultant cost. Among the quantities included in the costing algorithm are (1) labor and materials costs associated with initial plant construction, (2) operating expenses due to daytime and nighttime heat losses, and (3) operating expenses due to pumping power requirements. Two preliminary series of simulations were conducted to exercise the code. The results indicate that transport system costs for both dish and trough collector fields increase with field size and receiver exit temperature. Furthermore, dish collector transport systems were found to be much more expensive to build and operate than trough transport systems. ETRANS itself is stable and fast-running and shows promise of being a highly effective tool for the analysis of distributed solar thermal systems.
Date: September 1, 1980
Creator: Barnhart, J.S.
Object Type: Report
System: The UNT Digital Library
Stress analysis of MFTF-B getter system bellows. Final report (open access)

Stress analysis of MFTF-B getter system bellows. Final report

The MFTF-B design includes a retractable getter system. Eight getter assemblies are planned (4 in each end plug). Electrically heated Ti wires are mounted on a telescoping insertion mechanism and, between machine shots (pulses), are extended into the chamber in the vicinity of inward-facing water-cooled magnet liners. During the shots, the sublimators must be withdrawn because they will intrude into plasma and diagnostic space. Each of the getter assemblies will be mounted on the exterior of the vacuum vessel. Bellows are used to keep essentially all of the mechanism isolated from the vessel vacuum. The bellows come in two sizes (8.25'' O.D. and 14'' O.D.). The smaller of the two bellows has been qualified by testing up to 94,000 cycles by empirically adjusting details of the bellow design (geometry and thickness). The process required 12 different test samples and took over a one-year period to accomplish. The bellows consistently failed in the inside diameter weld heat-affected zone. Results from stress analysis studies are presented.
Date: April 1, 1982
Creator: Tokarz, F. J.; Johnson, J. J.; Mukherjee, A. N. & Dalder, E. N.
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
850/sup 0/C VHTR plant technical description (open access)

850/sup 0/C VHTR plant technical description

This report describes the conceptual design of an 842-MW(t) process heat very high temperature reactor (VHTR) plant having a core outlet temperature of 850/sup 0/C (1562/sup 0/F). The reactor is a variation of the high-temperature gas-cooled reactor (HTGR) power plant concept. The report includes a description of the nuclear heat source (NHS) and of the balance of reactor plant (BORP) requirements. The design of the associated chemical process plant is not covered in this report. The reactor design is similar to a previously reported VHTR design having a 950/sup 0/C (1742/sup 0/F) core outlet temperature.
Date: June 1, 1980
Creator: unknown
Object Type: Report
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
BURNUP DETERMINATION OF NUCLEAR FUELS. Project Report for the Quarter, April 1--June 30, 1968 and Final Report (open access)

BURNUP DETERMINATION OF NUCLEAR FUELS. Project Report for the Quarter, April 1--June 30, 1968 and Final Report

None
Date: March 1, 1969
Creator: Lisman, F. L.; Maeck, W. J.; Rein, J. E.; Foster, Jr., R. E.; Abernathey, R. M.; Delmore, Jr., J. E. et al.
Object Type: Report
System: The UNT Digital Library
Preparation of Charge Materials for Ornl Electromagnetic Isotope Separators (open access)

Preparation of Charge Materials for Ornl Electromagnetic Isotope Separators

SEPARATORS. C. W. Sheridan, H. R. Gwinn, and L. O. Descriptions are given of procedures, techniques, and equipment used to prepare charge materials for electromagnetic isotope separators at ORNL. Data on ion outputs during processing, charge consumption rates, and process efficiencies are given for 54 elements. (auth)
Date: August 1, 1962
Creator: Sheridan, C W; Gwinn, H R & Love, L O
Object Type: Report
System: The UNT Digital Library
Non-linear instability of DIII-D to error fields (open access)

Non-linear instability of DIII-D to error fields

Otherwise stable DIII-D discharges can become nonlinearly unstable to locked modes and disrupt when subjected to resonant m = 2, n = 1 error field caused by irregular poloidal field coils, i.e. intrinsic field errors. Instability is observed in DIII-D when the magnitude of the radial component of the m = 2, n = 1 error field with respect to the toroidal field is B{sub r21}/B{sub T} of about 1.7 {times} 10{sup {minus}4}. The locked modes triggered by an external error field are aligned with the static error field and the plasma fluid rotation ceases as a result of the growth of the mode. The triggered locked modes are the precursors of the subsequent plasma disruption. The use of an n = 1 coil'' to partially cancel intrinsic errors, or to increase them, results in a significantly expanded, or reduced, stable operating parameter space. Precise error field measurements have allowed the design of an improved correction coil for DIII-D, the C-coil'', which could further cancel error fields and help to avoid disruptive locked modes. 6 refs., 4 figs.
Date: October 1, 1991
Creator: La Haye, R. J. & Scoville, J. T.
Object Type: Article
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
Physical simulations of cavity closure in a creeping material (open access)

Physical simulations of cavity closure in a creeping material

The finite element method has been used extensively to predict the creep closure of underground petroleum storage cavities in rock salt. Even though the numerical modeling requires many simplifying assumptions, the predictions have generally correlated with field data from instrumented wellheads, however, the field data are rather limited. To gain an insight into the behavior of three-dimensional arrays of cavities and to obtain a larger data base for the verification of analytical simulations of creep closure, a series of six centrifuge simulation experiments were performed using a cylindrical block of modeling clay, a creeping material. Three of the simulations were conducted with single, centerline cavities, and three were conducted with a symmetric array of three cavities surrounding a central cavity. The models were subjected to body force loading using a centrifuge. For the single cavity experiments, the models were tested at accelerations of 100, 125 and 150 g's for 2 hours. For the multi-cavity experiments, the simulations were conducted at 100 g's for 3.25 hours. The results are analyzed using dimensional analyses. The analyses illustrate that the centrifuge simulations yield self-consistent simulations of the creep closure of fluid-filled cavities and that the interaction of three-dimensional cavity layouts can be investigated …
Date: September 1, 1985
Creator: Sutherland, H.J. & Preece, D.S.
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
Fifth high-energy heavy-ion study (open access)

Fifth high-energy heavy-ion study

This was the fifth of a continuing series of summer studies held at LBL to discuss high energy heavy ion collisions. Recently, a similar meeting has been held on alternate years at GSI (Darmstadt); and, in 1979, we held a meeting at LBL exclusively devoted to ultra-relativistic nuclear collisions. Two new features distinguish this study from earlier meetings in the series. First, the energy range for discussion was broadened by including collisions from about 20 MeV/nucleon to the highest available in the cosmic radiation. The lower range, particularly below 100 MeV/nucleon, will be under intense study in the near future with machines such as the upgraded Bevalac, Michigan State University Superconducting Cyclotron, GANIL in France, and the SC at CERN. Recently, the high energy collision regime has been expanded by the successful operation of the CERN ISR with alpha particles. Second, in addition to an extensive program of invited talks, we decided for the first time to actively solicit contributions. Forty-seven individual items from the conference were prepared separately for the data base. (GHT)
Date: October 1, 1981
Creator: unknown
Object Type: Article
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
Strontium-90 Fueled Thermoelectric Generator Power Source for Five-Watt U.S. Coast Guard Light Buoy. Final Report (open access)

Strontium-90 Fueled Thermoelectric Generator Power Source for Five-Watt U.S. Coast Guard Light Buoy. Final Report

The objectives of the SNAP 7A program were to design, manufacture, test, and deliver a five-watt electric generation system for a U. S. Coast Guard 8 x 26E light buoy. The 10-watt Sr/sup 90/ thermoelectric generator, the d-c-to-d-c converter, batteries and the method of installation in the light buoy are describcd. The SNAP 7A generator was fueled with four capsules containing a total of 40,800 curies of Sr/sup 90/ titanate. After fueling and testing, the SNAP 7A electric generating system was installed in the Coast Guard light buoy at Baltimore, Maryland, on December 15, 1961. Operation of the buoy lamp is continuous. (auth)
Date: February 1, 1962
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Applications of induction linac technology to heavy ion fusion (open access)

Applications of induction linac technology to heavy ion fusion

Evaluation of the application of heavy ion accelerators to ignite d-t pellets in a thermonuclear reactor is discussed. Accelerator design requirements considered include transport-limited current, beam injection conditions, and pulse bunching and focusing characteristics. The desirability of resonant and non-resonant accelerating structures is comparatively examined. The required power system switch tubes are discussed. It is concluded that heavy ion accelerators could offer a promising solution to the pellet-igniter problem. The advantages pointed out for this approach include electric efficiency greater than 10 percent, the possibility of high repetition rates (1 to 10 Hz), and a mature technological base. (RME)
Date: July 1, 1977
Creator: Faltens, A. & Keefe, D.
Object Type: Article
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)

Observations on the Effect of Selected Organic Materials on the Usable Potential Ranges of the Glassy Carbon, Pyrolytic Graphite, and Platinum Electrodes.

None
Date: January 1, 1968
Creator: Plock, C. E.
Object Type: Report
System: The UNT Digital Library
Pacific Northwest Laboratory, annual report for 1983 to the DOE Office of Energy Research. Part 4. Physical sciences (open access)

Pacific Northwest Laboratory, annual report for 1983 to the DOE Office of Energy Research. Part 4. Physical sciences

Part 4 of the Pacific Northwest Laboratory Annual Report for 1983 to the Office of Energy Research, includes those programs funded under the title Physical and Technological Research. The Field Task Program Studies reports in this document are grouped under the subheadings and each section is introduced by a divider page that indicates the Field Task Agreement reported in that section. These reports only briefly indicate progress made during 1983. The reader should contact the principal investigators named or examine the publications cited for more details.
Date: February 1, 1984
Creator: unknown
Object Type: Report
System: The UNT Digital Library
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
Development of a High Velocity Solid Particle Launcher for Laboratory Erosion Studies. [Reentry Vehicle Heat Shields] (open access)

Development of a High Velocity Solid Particle Launcher for Laboratory Erosion Studies. [Reentry Vehicle Heat Shields]

A solid particle launcher for laboratory erosion studies has been developed and successfully demonstrated. Performance of the launcher is predicted by a two-dimensional, time-dependent theoretical analysis to within the experimental uncertainty. The present device accelerates 100 μm diameter glass spheres to velocities of 2.1+/- 0.6 km/sec. The system is safe, reliable, and has a test repetition of about 2 shots/hour.
Date: March 1, 1975
Creator: Aeschliman, D. P.; Mulac, A. J.; Guzman, J. A.; Eaton, R. R. & Fox, R. L.
Object Type: Report
System: The UNT Digital Library