UNT Libraries Government Documents Department - 202 Matching Results

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open access

Plasma production and flow in ion beams

Description: Space charge neutralization of ion beams results from plasma generated by the beam. The two dimensional flow of plasma to walls surrounding a beam is analyzed to provide spatial distributions. Negative ion beams receive particular attention; the results are applied to electron control in beams subject to post-acceleration.
Date: August 22, 1977
Creator: Hooper, Jr. E. B. & Willmann, P. A.
open access

Dissolution processes. [224 references]

Description: This review contains more than 100 observations and 224 references on the dissolution phenomenon. The dissolution processes are grouped into three categories: methods of aqueous attack, fusion methods, and miscellaneous observations on phenomena related to dissolution problems. (DLC)
Date: October 22, 1976
Creator: Silver, G. L.
open access

Separation of B/sub 4/C powder by air classification

Description: Large quantities of bulk powder can be separated according to particle size and density by air classifiers. Classifiers disperse the powder and usually achieve size differentiation by drag and centrifugal forces acting on individual particles in the gas stream. A Donaldson ''acucut'' Classifier for the separation of B/sub 4/C powder is evaluated. Experimental tests were conducted to determine the particle cut sizes and powder yields obtained by variation of operating parameters. To assess the c… more
Date: December 22, 1976
Creator: Farrell, C. L. & Biermann, A. H.
open access

Predicting subsidence over coal-gasification sites

Description: The extent to which earth subsidence may be caused by in situ coal gasification is studied using the method of finite elements. This study takes into account rock failure modes and nonlinearity of rock stiffness. Two models were studied for the site at Hoe Creek, where a coal seam is overlain and underlain by interbedded clays and sandstones. These two studies are expected to bracket any subsidence that may occur. Maximum subsidence was 0.06 in. using the stiff model and 3.5 in. using the soft … more
Date: November 22, 1976
Creator: Langland, R. & Fletcher, D.
open access

Program for calculating x-ray powder diffraction interplanar (d) spacings with a Tektronix-31 desk top programmable calculator

Description: A Tektronix-31 (Tektronix Inc. Beaverton, Oregon) desk top calculator program, which is used as a backup to the PDP-8/I computer program, is described. The program yields interplanar (d) spacings and (2theta) angle values from measurements made on an x-ray diffraction film of a powdered sample of a crystalline material. Use of the calculator provides accurate computations in a relatively rapid time interval when the PDP-8/I is not functioning because of downtime for repairs, maintenance, etc.
Date: February 22, 1977
Creator: Eckstein, R. R. & Ishida, Y. G.
open access

Systematics of neutron-induced fisson cross sections over the energy range 0. 1 MeV to 15 MeV and at 0. 0253 eV

Description: Previous studies by Behrens have provided evidence of systematic behavior in neutron-induced fission cross sections in the incident neutron energy range 3 to 5 MeV. Recently measured fission cross-section ratios revealed this behavior. In this report, these measurements and those of others are used to illustrate the behavior of fission cross sections over the neutron energy range 0.1 MeV to 15 MeV. Similar trends are seen at 0.0253 eV, as revealed by thermal cross-section measurements. 12 figur… more
Date: June 22, 1977
Creator: Behrens, J. W.
open access

Suitability of Tophet C-Alloy 52/Kovar components to hydrogen environments

Description: The suitability of Tophet C-Alloy 52/Kovar weldments to hydrogen embrittlement were investigated because of their potential as candidate materials in fabrication of minaturized initiators for pyrotechnics. Cathodic charged samples were statically loaded for extended periods of time resulting in no load failures and in ductile fracture surfaces indicating resistance to hydrogen embrittlement. 20 figures.
Date: June 22, 1976
Creator: Gebhart, J. M. & Kelly, M. D.
open access

Soil structure interaction calculations: a comparison of methods

Description: Two approaches for calculating soil structure interaction (SSI) are compared: finite element and lumped mass. Results indicate that the calculations with the lumped mass method are generally conservative compared to those obtained by the finite element method. They also suggest that a closer agreement between the two sets of calculations is possible, depending on the use of frequency-dependent soil springs and dashpots in the lumped mass calculations. There is a total lack of suitable guideline… more
Date: July 22, 1976
Creator: Wight, L. & Zaslawsky, M.
open access

Program plan for the Brayton Isotope Power System. Phase I. Design, fabrication and test of the Brayton Isotope Power System

Description: Phase I of an overall program for the development of a 500 to 2000 W(e) (EOM), 7-y life, power system for space vehicles is discussed. The system uses a closed Brayton dynamic system to convert energy from an isotope heat source at a net efficiency greater than 25 percent. This first phase, a 35-month effort, is for the conceptual design of a 1300 W(e), 450 lb flight system and the design, fabrication, and test of a ground demonstration system. The flight system will use, for the baseline desig… more
Date: October 22, 1975
open access

Examination of temperature-induced shape memory of uranium--5. 3-to 6. 9 weight percent niobium alloys

Description: The uranium-niobium alloy system was examined in the range of 5.3-to-6.9 weight percent niobium with respect to shape memory, mechanical properties, metallography, Coefficients of linear thermal expansion, and differential thermal analysis. Shape memory increased with increasing niobium levels in the study range. There were no useful correlations found between shape memory and the other tests. Coefficients of linear thermal expansion tests of as-quenched 5.8 and 6.2 weight percent niobium speci… more
Date: September 22, 1976
Creator: Hemperly, V. C.
open access

LMFBR safety. 2. Review of current issues and bibliography of literature, 1970--1972

Description: This report discusses the current status of liquid-metal fast breeder reactor (LMFBR) development and one of the principal safety issues, a hypothetical core-disruptive accident (HCDA). Bibliographic information on worldwide LMFBRs relative to the development of the breeder reactor as a safe source of nuclear power is presented for the period 1970 through 1972. The bibliography consists of approximately 1620 abstracts covering early research and development and operating experiences leading up … more
Date: November 22, 1976
Creator: Buchanan, J. R. & Keilholtz, G. W.
open access

Advanced waste forms research and development. Comprehensive progress report

Description: Progress is reported in the following research areas: cesium fixation in aluminosilicates and supercalcine development; low sodium wastes and high sodium wastes. Phase relations in the appropriate (for supercalcine) portion of the Cs/sub 2/O-Al/sub 2/O/sub 3/-SiO/sub 2/ system are being investigated. Several compatibility lines (tie lines) have been established on the phase diagram. Methods of preparing pure single phases of CsAlSiO/sub 4/ and CsAlSi/sub 2/O/sub 6/ (pollucite) are being develop… more
Date: March 22, 1977
Creator: McCarthy, G. J.
open access

Decontamination of HEPA filters: April--June 1977

Description: Efforts this past quarter were directed toward the determination of dissolution parameters in various reagents of PuO/sub 2/, PuO/sub 2/-UO/sub 2/ solid solution, and AmO/sub 2/-PuO/sub 2/. The reagents used were various concentrations of HNO/sub 3/-HF-H/sub 2/SO/sub 4/, HNO/sub 3/-HF, HNO/sub 3/-(NH/sub 4/)/sub 2/Ce(NO/sub 3/)/sub 6/, and HNO/sub 3/-H/sub 2/SO/sub 4/. In one series of tests, simulated contaminated HEPA filter media were used. This material was prepared by mixing shredded filte… more
Date: September 22, 1977
Creator: Luthy, D. F. & Lewis, E. L.
open access

PWR blowdown heat transfer separate-effects program: Thermal-Hydraulic Test Facility experimental data report for test 100

Description: Reduced instrument responses are presented for Thermal-Hydraulic Test Facility (THTF) test 100, which is part of the ORNL Pressurized-Water-Reactor (PWR) Blowdown Heat Transfer Separate-Effects Program. The objective of the program is to investigate the thermal-hydraulic phenomenon governing the energy transfer and transport processes that occur during a loss-of-coolant accident in a PWR system. Test 100 was conducted to investigate the response of heater rod bundle 1 and instrumented spool pie… more
Date: June 22, 1977
Creator: White, M. D. & Hedrick, R. A.
open access

Formation and evaluation of convex-curved crystals of lithium fluoride for use in analyzing x-ray spectra

Description: Lithium fluoride as received from the vendor in boule form is 38 x 38 x 13 mm thick. This block is cleaved to wafers of the desired thickness, x-ray-evaluated for ''d'' spacing and greatest intensity, bent to the required radius, and then acid-etched to remove foreign material. The diffraction and dispersion characteristics of a wafer are analyzed using well-collimated tungsten x rays that strike the crystal and are diffracted onto no-screen x-ray film. If the crystal is satisfactory, it is mou… more
Date: July 22, 1976
Creator: Sellick, Barton O.
open access

Web-dendritic ribbon growth. USC solar report No. Q-3

Description: The web growth investigation portion of this program was spent in growing a backlog of primitive dendrites and developing a number of dendritic seed crystals having a variety of twin plane spacings. These seeds are to be used in the determination of the optimum twin spacing for dendritic-web growth. Having determined the optimum twin spacing for the seed dendrites, the optimized seeds will be used in the experimental part of the investigation to determine the limitation on the growth width and … more
Date: June 22, 1976
Creator: Hilborn, R. B. Jr. & Faust, J. W. Jr.
open access

Channeling and coherent bremsstrahlung effects for relativistic positrons and electrons. [16 to 28 MeV, orientation]

Description: Channeling of positrons in single crystals of silicon was observed in transmission and scattering measurements for incident energies from 16 to 28 MeV. In addition, the spectral dependence upon crystal orientation of the forward coherent bremsstrahlung produced by beams of 28-MeV positrons and electrons incident upon a 5 ..mu..m thick single crystal of silicon was measured with a NaI photon spectrometer. Effects of channeling and perhaps of the nonvalidity of the first Born approximation were o… more
Date: March 22, 1976
Creator: Walker, R. L.
open access

Report on process design studies of a tritium recovery process using dual temperature exchange with metal hydrides

Description: Studies were made of the process characteristics of a plant to decontaminate tritiated water using dual temperature exchange with VH/sub 2/. Feed to the plant consists of 300 kg/day on water containing 1 Ci/kg of tritium. A reference design was developed based on a decontamination factor of 10/sup 2/ and 10 kg/day of enriched product. This design requires a total of 48 ideal separation stages, 22 stages in the enriching section and 26 stages in the stripping section. Only low grade heat is requ… more
Date: January 22, 1976
Creator: Benenati, R. F.
open access

Observations on the operation of the SEMPEX code

Description: Observations on the use of the SEMPEX computer code are given. The issues of proper sampling rate and total sampling interval are addressed. The effect that noise in the data has on the results and the ability of autocorrelation, truncation filtering, and the sliding-window technique to reduce these effects are also discussed. 35 figures, 24 tables.
Date: September 22, 1977
Creator: Hudson, H. G. & Lager, D. L.
open access

Error field across the aperture of the ISABELLE dipole

Description: Error field multipoles due to systematic errors in the current distribution are computed and compared with the error field multipoles due to random errors in the current distribution. The systematic field error multipoles are found to vary rapidly across the aperture, and in some cases may be the dominant error multipoles.
Date: July 22, 1976
Creator: Parzen, G.
open access

Leaching of radioactive nuclides from cement grouts. [Method for measuring rate of leaching of Cs-137 from cement grouts]

Description: A method for measuring the rate of leaching of /sup 137/Cs from cement grouts was investigated as an alternate to the International Atomic Energy Agency (IAEA) method which requires long experimental times. The effects of curing time (10, 20, and 30 days) and the type of leachant (tap and saline water) on the amount of /sup 137/Cs leached were studied. Mathematical models for mass transport phenomena for both finite cylindrical geometry and a semi-infinite medium were developed to analyze the d… more
Date: May 22, 1974
Creator: Doerr, W. W.; Filiba, R. & Wang, M.
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