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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Heating rate measurements of selected laser-irradiated metals and non-metals using infrared radiometric techniques

Howard, Phil T. January 1979 (has links)
The heating curves for a number of different materials, including metals and non-metals, were observed while being irradiated with a beam from a C02 gas laser. The radiant energy spectrum emitted by the materials was measured and recorded, and from this data the heating and cooling rates of the materials were determined. Infrared measurements in the 3 to 5 micron and 8 to 14 micron regions were performed using two Barnes Spectral-Master Radiometers. Data was recorded with both stationary and moving target materials to determine the effect of airflow on the heating and cooling characteristics of the materials. The observed initial heating curve for the solid materials up to the melting point are compared with a theoretical model. The procedure for calibration of the equipment and for data collection is also contained in this thesis.These measurements are important because the experimental conditions closely approximate realistic environmental conditions for materials which are used in different types of aircraft during flight.
12

Structural and high pressure studies of some low and negative thermal expansion materials

Çetinkol, Mehmet. January 2008 (has links)
Thesis (Ph. D.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2009. / Committee Chair: Wilkinson, Angus; Committee Member: Barefield, E. Kent; Committee Member: Snyder, Robert; Committee Member: Soper, Jake; Committee Member: Zhang, Z. John. Part of the SMARTech Electronic Thesis and Dissertation Collection.
13

A comparative study of the comfort related properties of commercial apparel fabrics containing natural and man-made fibres / Comfort related properties of commercial apparel fabrics containing natural and man-made fibres

Stoffberg, Marguerite Ester January 2013 (has links)
The relationship between the fabric parameters, as independent variables, and the comfort related properties, as dependent variables, of commercial suiting fabrics, containing both natural and man-made fibres, have been studied. The fabric parameters measured in the study were mass, thickness, density, and air permeability. The comfort related properties, tested on a Permetest instrument, included water vapour permeability, water vapour resistance, and thermal resistance, with the moisture permeability index being derived. A total of 26 commercial suiting fabrics, covering a wide range of mass, as well as different fibre types and blends and fabric structures, was tested. The fibres covered, included wool, polyester, viscose, and cotton, while the fabric structures covered were 1x1 plain weave, 2x1 twill and 2x2 twill weave. The objectives of this study were to determine the empirical relationships between the measured fabric properties and the measured comfort related properties, and to determine the role, if any, of fibre type and fabric structure, since many claims are made in practice concerning the relative advantages, in terms of comfort, of a specific fibre type or blend, or fabric structure, over others, some of which being supported by research results. Since the fabrics covered, were commercial and were not engineered so that the different fabric parameters (independent variables) and fibre type and blend, as well as fabric structure could be varied independently of each other, the effects of the various fabric parameters on the fabric comfort related properties were determined and quantified by multiple regression analyses (multi-linear and multi-quadratic), and the best fit regression equations, and contribution of each parameter to the overall fit established. It was found that fabric thickness and fabric mass had the largest effect on the comfort related properties as measured here, fabric mass determining, to a large extent, water vapour permeability, and fabric thickness, thermal resistance. The rest of the fabric parameters included in the study had only a relatively small effect on the measured comfort related properties. The influence of fabric parameters, with particular reference to mass and thickness, on the measured comfort related properties, were much greater than that of fibre type or blend, or fabric structure. It was, therefore, concluded from this study, that the fabric parameters, as opposed to the intrinsic characteristics of a particular fibre, whether natural or man-made, largely determined those fabric comfort related properties measured here.
14

Thermophysical properties of biofuel components derived from biomass

Nduli, Mbalenhle B. January 2016 (has links)
Submitted in fulfillment of the academic requirements of the degree of Master of Technology, Durban University of Technology, Durban, South Africa, 2016. / The thermophysical properties of the binary mixtures containing biofuel components derived from biomass were determined. Experimental densities, speed of sound, and refractive indices for the binary mixtures (methanol or 1-ethyl-3-methylimidazolium acetate [EMIM][OAc] + furfural or furfuryl alcohol ) were measured at T = (298.15, 303.15, 308.15, 313.15 and 318.15) K. From the experimental data, excess molar volume, E m V , isentropic compressibility, s  , molar refractions, R, and deviation in refractive index, Δn, were calculated. The excess molar volumes were found to be negative for all systems studied. The isentropic compressibility were found to be both positive for the whole composition and temperature range and increases slightly with increasing temperature. The deviation in refractive index was positive over the whole composition range. The obtained values of excess molar volumes and changes of refractive index on mixing were satisfactorily correlated by the Redlich–Kister equation. The Lorentz–Lorenz equation was applied to predict the density and calculate the excess molar volume of the binary mixtures. / M
15

Thermal properties of nanostructured Pd₈₂Si₁₈ alloy. / 納米鈀硅合金的熱性質 / Thermal properties of nanostructured Pd₈₂Si₁₈ alloy. / Na mi ba gui he jin de re xing zhi

January 2000 (has links)
Chan Chun Wai = 納米鈀硅合金的熱性質 / 陳進偉. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 18-20). / Text in English; abstracts in English and Chinese. / Chan Chun Wai = Na mi ba gui he jin de re xing zhi / Chen Jinwei. / Acknowledgements --- p.III / Abstract --- p.IV / 摘要 --- p.V / Chapter Chapter One ´ؤ --- Introduction / Chapter 1.1 --- Novel materials in the 21st century --- p.1 / Chapter 1.2 --- What are Nanocrystalline Materials? --- p.1 / Chapter 1.3 --- The superior properties of Nanocrystalline Materials --- p.2 / Chapter 1.4 --- Fabrication of Nanocrystalline Materials --- p.3 / Chapter 1.5 --- Flaws of the as-produced Nanophase Materials --- p.4 / Chapter 1.6 --- Theory of Phase Separation --- p.4 / Chapter 1.7 --- Nucleation and Growth --- p.6 / Chapter 1.7.1 --- Homogeneous nucleation / Chapter 1.7.2 --- Heterogeneous nucleation / Chapter 1.8 --- Spinodal Decomposition / Chapter 1.8.1 --- How SD differs from the classical diffusion process? / Chapter 1.8.2 --- Dynamics of SD / Chapter 1.8.3 --- How can we distinguish SD from Nucleation and Growth? / Chapter 1.8.4 --- Pore-free nanophase materials produced by Liquid Phase SD / Chapter 1.9 --- Thermal properties of the pore-free nanostructured Pd82Si18 Alloy --- p.12 / Chapter 1.9.1 --- A review of grain growth in nanophase materials / Chapter 1.9.2 --- Grain growth study on LSD Pd82Si18 alloy 一 aim and prospect / References --- p.18 / Figures --- p.21 / Chapter Chapter Two 一 --- Experimental / Chapter 2.1 --- Introduction --- p.28 / Chapter 2.2 --- From preparation of samples to microstructure analysis --- p.28 / Chapter 2.2.1 --- Alloying / Chapter 2.2.2 --- Fluxing / Chapter 2.2.3 --- Rapid Solification / Chapter 2.2.4 --- Annealing / Chapter 2.2.5 --- Microstructure analysis / Figures --- p.31 / Chapter Chapter Three ´ؤ --- Results and discussions / Thermal stability of bulk nanostructured alloys prepared by liquid phase spinodal decomposition --- p.34 / References --- p.40 / Table --- p.43 / Figures --- p.44 / Chapter Chapter Four ´ؤ --- Conclusions --- p.61
16

The specific heat of composite material at low temperatures.

January 1979 (has links)
by Chan Man-ng. / Thesis (M.Ph.)--Chinese University of Hong Kong. / Bibliography: l. 108.
17

The magnetic properties, crystal and magnetic structures of Nd5SixGe4-x /

Wang, Huabin, 1969- January 2007 (has links)
No description available.
18

The thermal conductivity properties of masonry materials native to Southern Arizona

Jones, Charles Earl, 1934- January 1956 (has links)
No description available.
19

Laboratory measurements of the thermal conductivity and thermal diffusivity of methane hydrate at simulated in situ conditions

deMartin, Brian J. 05 1900 (has links)
No description available.
20

Reduction of radiated thermal conductivity in thin-wall hollow ceramic spheres using scattering phases

Furlong, Scott Davis 12 1900 (has links)
No description available.

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