617 Matching Results

Search Results

Advanced search parameters have been applied.

in subjects: "Thermal Expansion"

open access

High-temperature of thermodynamic properties of sodium

The set of high-temperature thermodynamic properties for sodium in the two-phase and subcooled-liquid regions which was previously recommended, has been modified to incorporate recent experimental data. In particular, replacement of the previously estimated critical constants with experimentally-determined values has resulted in substantial differences in the region of the critical point. The following thermodynamic properties were determined: pressure, density, enthalpy, entropy, internal ener… more

Date: January 1, 1977

Creator: Padilla, A. Jr.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Thermal strains in titanium aluminide and nickel aluminide composites

Neutron diffraction was used to measure residual thermal strains developed during postfabrication cooling in titanium aluminide and nickel aluminide intermetallic matrix composites. Silicon carbide /Ti 14Al-21Nb, tungsten and sapphire/NiAl, and sapphire and SiC-coated sapphire/NiAl{sub 25}Fe{sub 10} composites were investigated. The thermal expansion coefficient of the matrix is usually greater than that of the fibers. As such, during cooldown, compressive residual strains are generated in the … more

Date: January 1, 1992

Creator: Saigal, A. (Tufts Univ., Medford, MA (United States). Dept. of Mechanical Engineering) & Kupperman, D.S. (Argonne National Lab., IL (United States))

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

MHD power generation research, development and engineering. Quarterly progress report, October-December 1979

Progress is reported on the following tasks: characterization of coal for open-cycle MHD power generation systems; compressive creep and strength studies of MHD preheater materials; preparation of coals for utilization in direct coal-fired MHD generation; characterization of volatile matter in coal; MHD materials evaluation; operability of the Moderate Temperature Slag Flow Facility; slag-seed equilibria and separations related to the MHD system; thermionic emission of coal and electrode materi… more

Date: January 1, 1979

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Phenolic resin syntactic foams

Syntactic foams were prepared from blends of six phenolic resins and carbon microbubbles. The compressive strength of the phenolic resin foams is equivalent to the strength of foams made from a polyimide resin. Ammonia evolved during the cure diffuses rapidly and is not bound by the foam.

Date: June 1, 1980

Creator: McIlroy, H. M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Failure of sheathed thermocouples due to thermal cycling

Open circuit failures (up to 100%) in small-diameter thermocouples used in electrically heated nuclear fuel rod simulator prototypes during thermal cycling tests were investigated to determine the cause(s) of the failures. The experiments conducted to determine the relative effects of differential thermal expansion, wire size, grain size, and manufacturing technology are described. It was concluded that the large grain size and embrittlement which result from certain common manufacturing anneal… more

Date: March 1, 1982

Creator: Anderson, R.L. & Ludwig, R.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Survey of physical property data for several alloys. [Nitronic 33; copper C10400; copper C17510]

This report summarizes an examination of physical property data available in the literature for six alloys of potential interest to the Toroidal Fusion Core Experiment in the Fusion Energy Program. The properties of thermal expansion, density, specific heat, electrical resistivity, and thermal conductivity were compiled for six alloys: Nitronic 33, a low-nickel, high manganese stainless steel; nickel-base Inconnel Alloys 625, 718, and X-750; and copper alloys C10400 and C17510. The temperatures… more

Date: August 1, 1985

Creator: Pawel, R. E. & Williams, R. K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Analysis of fuel relocation for the NRC/PNL Halden assemblies IFA-431, IFA-432, and IFA-513

The effects of the thermally-induced cracking and subsequent relocation of UO/sub 2/ fuel pellets on the thermal and mechanical behavior of light-water reactor fuel rods during irradiation are quantified in this report. Data from the Nuclear Regulatory Commission/Pacific Northwest Laboratory Halden experiments on instrumented fuel assemblies (IFA) IFA-431, IFA-432, and IFA-513 are analyzed. Beginning-of-life in-reactor measurements of fuel center temperatures, linear heat ratings, and cladding … more

Date: April 1, 1980

Creator: Williford, R. E.; Mohr, C. L.; Lanning, D. D.; Cunningham, M. E.; Rausch, W. N. & Bradley, E. R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Instrument evaluation, calibration, and installation for the heater experiments at Stripa

Borehole instrumentation for the measurement of temperature, displacement, and stress was evaluated, modified, calibrated, and installed in an underground site at Stripa, Sweden where experiments are currently underway to investigate the suitability of granite as a storage medium for nuclear waste. Three arrays of borehole instrumentation measure the thermomechanical effects caused by electrical heaters which simulate the thermal output of canisters of radioactive waste. Because most rock mecha… more

Date: December 1, 1979

Creator: Schrauf, T.; Pratt, H.; Simonson, E.; Hustrulid, W.; Nelson, P.; DuBois, A. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Mossbauer effect and neutron diffraction study of the anomalous lattice behavior of U/sub 6/Fe

Neutron diffraction and /sup 57/Fe Moessbauer effect measurements have been made on the exchange-enhanced superconductor U/sub 6/Fe. The neutron diffraction results indicate a pronounced anisotropy in the thermal expansion of the unit cell and an anomalous temperature dependence for the c-axis component of the total Debye-Waller factor of Fe below 100K. The Moessbauer effect measurements show non-Debye behavior in the mean-squared displacement of Fe, with phonon hardening occurring below 100K. … more

Date: June 1, 1985

Creator: Vaishnava, P. P.; Dwight, A. E.; Kimball, C. W.; Jorgensen, J. D. & Fradin, F. Y.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

A simple model for radial expansion reactivity in LMRs (liquid metal reactors)

Presented in this report is a simple analytical model developed for evaluating the radial expansion reactivity in small modular liquid metal reactors (LMRs). The present model is based on a non-leakage representation of the effective neutron multiplication factor. The resultant analytical expression for the radial expansion reactivity is simple and can be used directly in a system code for safety analyses. Applications of the present model to PRISM and SAFR resulted in a good agreement with the… more

Date: January 1, 1988

Creator: Cheng, H.S. & Van Tuyle, G.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Fuel cells: applied research fuel cell materials and electrocatalysis. Annual report, January 1976--December 1976

Research is described on electrocatalysis of fuel cell reactions including the topics (1) mixed oxides as oxygen electrodes, (2) electrolyte effects on the oxygen reduction reaction, (3) anion effects on the oxygen reduction reaction, and (4) selection and evaluation of electrocatalysts for oxygen reduction in KHCO/sub 3//K/sub 2/CO/sub 3/ buffered electrolytes. Phosphoric acid fuel cell studies include inhibition of sintering of fuel cell catalyst particles: electrochemical methods for surface… more

Date: September 1, 1977

Creator: Srinivasan, S. & Isaacs, H. S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Thermoelectric materials evaluation program. Technical summary report

Research progress on the thermoelectric materials evaluation program is reported covering the period January 1, 1976 to September 30, 1978. Topical reports are presented on (1) hot and cold end ..delta..T's, (2) hardware mobility, (3) p-leg sublimation suppression, (4) thermodynamic stability of p-legs, (5) n-leg material process improvements to reduce extraneous resistance, (6) n-leg cracking, (7) dynamic evaluation of converter, and (8) data base and degradation modes. Twenty attachments are … more

Date: April 1979

Creator: Hinderman, J.D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Physical properties of kraft black liquor. Final report. Phase I

Methods were selected, equipment installed, and procedures developed for determining rheological properties; for determining thermal properties (stability, density, thermal expansion, and heat capacity); for purification and characterization of lignin (glass transition, stability, weight average molecular weight, and number average molecular weight); and for performing chemical analyses (negative inorganic ions, positive inorganic ions, acid organic salts, lignin, and total solids). A strategy … more

Date: December 1, 1983

Creator: Fricke, A.L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Cross-hole investigation of a rock mass subjected to heating

A cross-hole high-frequency acoustic investigation of a granitic rock mass subjected to sustained heating is reported. Compressional and shear-wave velocity measurements along four different paths between four vertical boreholes made prior to turning on the heater, during 398 days of heating and after the heater was turned off correlated well with the presence of fracture zones, in which the fractures were closed by thermal expansion of the rock upon heating. When the rock mass cooled, the velo… more

Date: April 1, 1980

Creator: Paulsson, B.N.P. & King, M.S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Thermal properties measurements on rocksalt samples from the site of the proposed Waste Isolation Pilot Plant

Thermal conductivity, thermal expansion, and specific heat measurements have been made on a number of specimens. The specific heat measurements were made by differential scanning calorimetry and the results showed that the specific heats of both clean rocksalt samples and of dirty samples with less than or equal to 7% insoluble impurities were essentially identical to the published specific heat for pure NaCl. In the thermal expansion measurements, two distinct groups of samples were identified… more

Date: May 13, 1980

Creator: Sweet, J. N. & McCreight, J. E.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Silicon-on ceramic process. Silicon sheet growth and device developmentt for the Large-Area Silicon Sheet Task of the Low-Cost Solar Array Project. Quarterly report No. 13, October 1-December 31, 1979

Research on the technical and economic feasibility of producing solar-cell-quality sheet silicon by coating inexpensive ceramic substrates with a thin layer of polycrystalline silicon is reported. The coating methods to be developed are directed toward a minimum-cost process for producing solar cells with a terrestrial conversion efficiency of 11 percent or greater. By applying a graphite coating to one face of a ceramic substrate, molten silicon can be caused to wet only that graphite-coated f… more

Date: February 15, 1980

Creator: Chapman, P W; Zook, J D; Grung, B L; McHenry, K & Schuldt, S B

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Silicon on ceramic process. Silicon sheet growth development for the Large-Area Silicon Sheet Task of the Low-Cost Silicon Solar Array Project. Annual report No. 2, September 17, 1976--September 19, 1977

The objective of this research program is to investigate the technical and economic feasibility of producing solar-cell-quality sheet silicon by coating one surface of carbonized ceramic substrates with a thin layer of large-grain polycrystalline silicon from the melt. In the past year significant progress was made in all areas of the program. The physical and chemical properties of the standard mullite refractory used for the majority of the coating runs (McDanel MV20 and Coors S1SI) have been… more

Date: September 30, 1977

Creator: Zook, J.D.; Heaps, J.D.; Maciolek, R.B.; Koepke, B.; Butter, C.D. & Schuldt, S.B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Rock Properties and Their Effect on Thermally-Induced Displacements and Stresses

A discussion is given of the importance of material properties in the finite-element calculations for thermally induced displacements and stresses resulting from a heating experiment in an in-situ granitic rock, at Stripa, Sweden. Comparisons are made between field measurements and finite element method calculations using (1) temperature independent, (2) temperature dependent thermal and thermomechanical properties and (3) in-situ and laboratory measurements for Young's modulus. The calculation… more

Date: February 1, 1980

Creator: Chan, T.; Hood, M. & Board, M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Coefficient of thermal expansion of fluorinert as a function of volume percent absorbed air

The relationship between the coefficient of volumetric thermal expansion of liquid Fluorinert FC-86 and the volume percent of absorbed air was examined experimentally. A special test apparatus was built for this purpose. A floating liquid seal was used to isolate the Fluorinert sample from the atmosphere. This prevented gas absorption during thermal cycling yet allowed the sample to expand and contract freely during testing. It was found that the coefficient of thermal expansion is not influenc… more

Date: June 1, 1982

Creator: Reilly, J.M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Status of the lanthanides and actinides in the periodic table

In extended discussions and correspondence with Ekkehard Fluck, the author was made aware of a problem with the Periodic Table, i.e., which element should be shown in the main table as the representative of the lanthanide series and the actinide series. In earlier discussion, he came to the conclusion that lanthanum and actinium are not the elements which should appear, but rather lutetium and lawrencium are more appropriate for inclusion in their place. This paper will attempt to justify the r… more

Date: January 1, 1985

Creator: Holden, Norman E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The effect of expansion-ratio limitations on positive-displacement, total-flow geothermal power systems

Combined steam-turbine/positive-displacement engine (PDE) geothermal power systems are analyzed thermodynamically and compared with optimized reference flash-steam plants. Three different configurations of combined systems are considered. Treated separately are the cases of self-flowing and pumped wells. Two strategies are investigated that help overcome the inherent expansion-ratio limitation of PDE's: pre-flashing and pre-mixing. Parametrically-obtained results show the required minimum PDE e… more

Date: February 1, 1982

Creator: DiPippo, R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Advanced materials for space nuclear power systems

Research on monolithic refractory metal alloys and on metal matrix composites is being conducted at the NASA Lewis Research Center, Cleveland, Ohio, in support of advanced space power systems. The overall philosophy of the research is to develop and characterize new high-temperature power conversion and radiator materials and to provide spacecraft designers with material selection options and design information. Research on three candidate materials (carbide strengthened niobium alloy PWC-11 fo… more

Date: January 1, 1991

Creator: Titran, R. H.; Grobstein, T. L. & Ellis, D. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Stress relaxation and hillock growth in thin films

The relaxation of thermal stress in a thin film adhering to a substrate of differing expansion coefficient is discussed. Good agreement is found between literature data on relaxation during isothermal anneals of Pb films at up to 350/sup 0/K and model calculations based on a state variable description of plastic flow. The stress system during relaxation is explored, and the absence of diffusional creep is explained. The plasticity-dominated relaxation process suggested by this analysis is shown… more

Date: January 1, 1978

Creator: Jackson, M. S. & Li, C. Y.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Thermal Cycling on Fatigue Failure of the Plutonium Vitrification Melter

One method for disposition of excess plutonium is vitrification into cylindrical wasteforms. Due to the hazards of working with plutonium, the vitrification process must be carried out remotely in a shielded environment. Thus, the equipment must be easily maintained. With their simple design, induction melters satisfy this criterion, making them ideal candidates for plutonium vitrification. However, due to repeated heating and cooling cycles and differences in coefficients of thermal expansion … more

Date: February 11, 2009

Creator: Jordan, Jeffrey & Gorczyca, Jennifer

Item Type: Article

Partner: UNT Libraries Government Documents Department