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Thermal Conductivity of Solids At Room Temperature and Below: A Review and Compilation of the Literature

Description: From Abstract: "An extensive compilation is given of the measured values of thermal conductivity for nearly all solid materials from room temperature down to 0.02 kelvin. Experimental methods and physical phenomena are discussed in the text and coded in the tables for references for which curves are shown."
Date: September 1973
Creator: Childs, Gregg E.; Ericks, Lewis J. & Powell, Robert L.
Partner: UNT Libraries Government Documents Department

Thermal Conductivity of 14 Metals and Alloys Up to 1100 Degrees Fahrenheit

Description: Memorandum presenting a determination of the thermal conductivity of 14 metals and alloys in temperatures ranges with a maximum of 1100 degrees Fahrenheit. Some of the metals included steels, high-temperature alloys, molybdenum disilicide, aluminum alloys, brass, and silver. A comparison method was used to obtain the results in which the thermal conductivity of the test sample was compared with the conductivity of high-purity lead.
Date: March 2, 1951
Creator: Evans, Jerry E., Jr.
Partner: UNT Libraries Government Documents Department

Experimental Thermal Conductivities of the N2D4 Is in Equilibrium to 2NO2 System

Description: Report presenting an investigation of direct measurements of the thermal conductivity of reacting gas systems. The hot-wire measurement technique was used at a range of temperatures and pressures. A comparison of the theoretical and experimental results are provided.
Date: February 1958
Creator: Coffin, Kenneth P. & O'Neal, Cleveland, Jr.
Partner: UNT Libraries Government Documents Department

Calculated thermal conductivities of pure gases and gaseous mixtures at elevated temperatures

Description: From summary: "A method of calculating thermal conductivities of gases and mixtures of gases at elevated temperatures is presented. Results for carbon dioxide, helium, neon, nitrogen, and their binary mixtures are given for the temperature range of 273 degrees Kelvin to 800 degrees Kelvin. The calculated results for the pure gases are in agreement with the known experimental data."
Date: 1951
Creator: Wright, J. M.
Partner: UNT Libraries Government Documents Department

Thermal Conductivity of UO2

Description: Report discussing the thermal conductivity of uranium dioxide. The first part of the report includes the thermal effects on the substance's physical form, while the second part describes the experimental details.
Date: September 1962
Creator: Daniel, J. L.; Matolich, J., Jr. & Deem, H. W.
Partner: UNT Libraries Government Documents Department

Thermal conductivity of thermal-battery insulations

Description: The thermal conductivities of a variety of insulating materials used in thermal batteries were measured in atmospheres of argon and helium using several techniques. (Helium was used to simulate the hydrogen atmosphere that results when a Li(Si)/FeS{sub 2} thermal battery ages.) The guarded-hot-plate method was used with the Min-K insulation because of its extremely low thermal conductivity. For comparison purposes, the thermal conductivity of the Min-K insulating board was also measured using the hot-probe method. The thermal-comparator method was used for the rigid Fiberfrax board and Fiberfrax paper. The thermal conductivity of the paper was measured under several levels of compression to simulate the conditions of the insulating wrap used on the stack in a thermal battery. The results of preliminary thermal-characterization tests with several silica aerogel materials are also presented.
Date: August 1, 1995
Creator: Guidotti, R.A. & Moss, M.
Partner: UNT Libraries Government Documents Department

High-Precision Micropipette Thermal Sensor for Measurement of Thermal Conductivity of Carbon Nanotubes Thin Film

Description: The thesis describes novel glass micropipette thermal sensor fabricated in cost-effective manner and thermal conductivity measurement of carbon nanotubes (CNT) thin film using the developed sensor. Various micrometer-sized sensors, which range from 2 µm to 30 µm, were produced and tested. The capability of the sensor in measuring thermal fluctuation at micro level with an estimated resolution of ±0.002oC is demonstrated. The sensitivity of sensors was recorded from 3.34 to 8.86 µV/oC, which is independent of tip size and dependent on the coating of Nickel. The detailed experimental setup for thermal conductivity measurement of CNT film is discussed and 73.418 W/moC was determined as the thermal conductivity of the CNT film at room temperature.
Date: August 2011
Creator: Shrestha, Ramesh
Partner: UNT Libraries

Properties of some expanded plastics and other low-density materials

Description: Report presenting an investigation of various mechanical and physical properties of several expanded plastics and other low-density materials of interest for aircraft applications, such as heat insulation or the core of a sandwich material. The materials in the investigation included cellulose acetate plastic, polystyrene, a urea-formaldehyde resin, a zein product, hard rubber, balsa wood, and cellular glass.
Date: September 1945
Creator: Axilrod, Benjamin M. & Koenig, Evelyn
Partner: UNT Libraries Government Documents Department

Determining the Emissivity of Roofing Samples: Asphalt, Ceramic and Coated Cedar

Description: The goal is to perform heat measurements examine of selected roofing material samples. Those roofing materials are asphalt shingles, ceramics, and cedar. It’s important to understand the concept of heat transfer, which consists of conduction, convection, and radiation. Research work was reviewed on different infrared devices to see which one would be suitable for conducting my experiment. In this experiment, the main focus was on a specific property of radiation. That property is the emissivity, which is the amount of heat a material is able to radiate compared to a blackbody. An infrared measuring device, such as the infrared camera was used to determine the emissivity of each sample by using a measurement formula consisting of certain equations. These equations account for the emissivity, transmittance of heat through the atmosphere and temperatures of the samples, atmosphere and background. The experiment verifies how reasonable the data is compared to values in the emissivity table. A blackbody method such as electrical black tape was applied to help generate the correct data. With this data obtained, the emissivity was examined to understand what factors and parameters affect this property of the materials. This experiment was conducted using a suitable heat source to heat up the material samples to high temperature. The measurements were taken during the experiment and displayed by the IR camera. The IR images show the behavior of surface temperatures being distributed throughout the different materials. The main challenge was to determine the most accurate emissivity values for all material samples. The results obtained by the IR camera were displayed in figures and tables at different distances, which was between the heap lamp and materials. The materials exhibited different behaviors in temperature and emissivity at certain distances. The emissivity of each material varied with different temperatures. The results led to suggestions ...
Date: December 2015
Creator: Adesanya, Oludamilola
Partner: UNT Libraries

Holey Silicon as an Efficient Thermoelectric Material

Description: This work investigated the thermoelectric properties of thin silicon membranes that have been decorated with high density of nanoscopic holes. These ?holey silicon? (HS) structures were fabricated by either nanosphere or block-copolymer lithography, both of which are scalable for practical device application. By reducing the pitch of the hexagonal holey pattern down to 55 nm with 35percent porosity, the thermal conductivity of HS is consistently reduced by 2 orders of magnitude and approaches the amorphous limit. With a ZT value of 0.4 at room temperature, the thermoelectric performance of HS is comparable with the best value recorded in silicon nanowire system.
Date: September 30, 2010
Creator: Tang, Jinyao; Wang, Hung-Ta; Hyun Lee, Dong; Fardy, Melissa; Huo, Ziyang; Russell, Thomas P. et al.
Partner: UNT Libraries Government Documents Department

Estimation of composite thermal conductivity of a heterogeneousmethane hydrate sample using iTOUGH2

Description: We determined the composite thermal conductivity (ktheta) ofa porous methanehydrate sample (composedof hydrate, water, and methan egas) as a function of density using iTOUGH2. X-ray computed tomography(CT) was used to visualize and quantify the density changes that occurredduring hydrate formation from granular ice. The composite thermalconductivity was estimated and validated by minimizing the differencesbetween the observed and the predicted thermal response using historymatching. The estimated density-dependent composite thermal conductivityranged between 0.25 and 0.58 W/m/K.
Date: May 15, 2006
Creator: Gupta, Arvind; Kneafsey, Timothy J.; Moridis, George J.; Seol,Yongkoo; Kowalsky, Michael B. & Sloan Jr., E.D.
Partner: UNT Libraries Government Documents Department

Effect of in-pile degradation of the meat thermal conductivity on the maximum temperature of the plate-type U-Mo dispersion fuels

Description: Effect of in-pile degradation of thermal conductivity on the maximum temperature of the plate-type research reactor fuels has been assessed using the steady-state heat conduction equation and assuming convection cooling. It was found that due to very low meat thickness, characteristic for this type of fuel, the effect of thermal conductivity degradation on the maximum fuel temperature is minor. For example, the fuel plate featuring 0.635 mm thick meat operating at heat flux of 600 W/cm2 would experience only a 20oC temperature rise if the meat thermal conductivity degrades from 0.8 W/cm-s to 0.3 W/cm-s. While degradation of meat thermal conductivity in dispersion-type U-Mo fuel can be very substantial due to formation of interaction layer between the particles and the matrix, and development of fission gas filled porosity, this simple analysis demonstrates that this phenomenon is unlikely to significantly affect the temperature-based safety margin of the fuel during normal operation.
Date: November 1, 2009
Creator: Medvedev, Pavel G.
Partner: UNT Libraries Government Documents Department

Conductivities and Seebeck Coefficients of Boron Carbides: ''Softening-Bipolaron'' Hopping

Description: The most conspicuous feature of boron carbides' electronic transport properties is their having both high carrier densities and large Seebeck coefficients. The magnitudes and temperature dependencies of the Seebeck coefficients are consistent with large contributions from softening bipolarons: singlet bipolarons whose stabilization is significantly affected by their softening of local vibrations. Boron carbides' high carrier densities, small activation energies for hopping ({approx} 0.16 eV), and anomalously large Seebeck coefficients combine with their low, glass-like thermal conductivities to make them unexpectedly efficient high-temperature thermoelectrics.
Date: July 20, 2000
Partner: UNT Libraries Government Documents Department