This experimental study contains two points; part1 – turbine blade heat transfer under low Reynolds number flow conditions, and part 2 – trailing edge cooling and heat transfer. The effect of unsteady wake and free stream turbulence on heat transfer and pressure coefficients of a turbine blade was investigated in low Reynolds number flows. The experiments were performed on a five blade linear cascade in a low speed wind tunnel. A spoked wheel type wake generator and two different turbulence grids were employed to generate different levels of the Strouhal number and turbulence intensity, respectively. The cascade inlet Reynolds number based on blade chord length was varied from 15,700 to 105,000, and the Strouhal number was varied from 0 to 2.96 by changing the rotating wake passing frequency (rod speed) and cascade inlet velocity. A thin foil thermocouple instrumented blade was used to determine the surface heat transfer coefficient. A liquid crystal technique based on hue value detection was used to measure the heat transfer coefficient on a trailing edge film cooling model and internal model of a gas turbine blade. It was also used to determine the film effectiveness on the trailing edge. For the internal model, Reynolds numbers based on the hydraulic diameter of the exit slot and exit velocity were 5,000, 10,000, 20,000, and 30,000 and corresponding coolant – to – mainstream velocity ratios were 0.3, 0.6, 1.2, and 1.8 for the external models, respectively. The experiments were performed at two different designs and each design has several different models such as staggered / inline exit, straight / tapered entrance, and smooth / rib entrance. The compressed air was used in coolant air. A circular turbulence grid was employed to upstream in the wind tunnel and square ribs were employed in the inlet chamber to generate turbulence intensity externally and internally, respectively.

Soil suction is one of the most important physical variables affecting the soil engineering behavior, moisture content. Suction has a major controlling influence on soil shear strength. The moisture diffusivity properties of unsaturated properties of soils exert a critical influence on the depth to which seasonal variations of moisture and suction at the ground surface extend into the soil mass. Hence, a study of moisture diffusion coefficient is pivotal. In this research the drying test originally proposed by Mitchell (1979) has been validated by back calculating the moisture diffusion values using the empirical relation established by Lytton (2003). The non-linear flow through unsaturated soils has been simplified to a linear problem for simplicity in this study. Owing to this simplification, certain refinements have therefore been applied in the determination of diffusion coefficient. Thermocouple psychrometer was used to measure the soil suction along the length of the sample and at different times in the laboratory. Initial suction measurements were done using the filter paper test. Curve fitting procedure established by (Aubeny and Lytton, 2003), has been used for the determination of the diffusion coefficient. Analytical validation of the moisture diffusion coefficient, required coefficient of permeability, ??k??, slope of suction water characteristic curve ??S?? and air entry value ??ho?? as the major input parameters. Mitchell (1979) assumed the value of ??ho?? to be 100 cm. In this research air entry value, ??ho?? has been re-evaluated and it comes out to be higher than the pre estimated value. The value of slope of suction water characteristic curve, ??S?? obtained from pressure plate tests, compares well to the empirical equation of Lytton (2003). The results of moisture diffusion coefficient obtained from the empirical equation come out in the same range as obtained from the refined Mitchell??s (1979) drying test. The refinements includes introduction of constant temperature environment. Owing to the least variation in temperature, more reliable and reproducible data was obtained. The range of moisture diffusion coefficient, ??-values obtained from empirical equation, comes out to be coherent with the laboratory data. Hence, it can be concluded that the research was successful.

The presence of moisture in hot mix asphalt (HMA) causes loss of strength and durability of the mix, which is referred to as moisture damage. This study deals with the development of experimental methods for measuring total suction in HMA, which can be defined as the free energy state of water in HMA mixes. The total suction is related to the ability of moisture to get into the mix under unsaturated conditions; it is also related to the ability of the mix to retain moisture. Soil suction has been studied extensively. However, suction in HMA as a porous material and its relationship to moisture damage have not been studied. The development of a procedure to measure the total suction in HMA mixes is the first objective of this research. The second objective is to relate suction measurements to physical and chemical properties of the mixtures. The objectives were achieved in two phases. In the first phase, the total suction was measured in HMA specimens with different types of aggregates (limestone and granite), and with different air void distributions and aggregate gradations. The results of this phase showed that the drying test using a 60 oC temperature-controlled room is the proper setup for measuring the total suction in HMA using thermocouple psychrometers. The characteristics of suction-moisture content curves were found to be related to the air void distribution in HMA. In the second phase, total suction was measured in sand asphalt specimens. These specimens had different combinations of aggregates and binders with different bond energies and exhibited different field performance in terms of resistance to moisture damage. The suction measurements in sand asphalt specimens were used to calculate the moisture diffusion coefficient. The results revealed that water diffused into sand asphalt specimens that are known to have poor resistance to moisture damage faster than those that are known to have good resistance to moisture damage

Energy use index (EUI) is an important measure of energy use which normalizes energy use by dividing by building area. Energy use indices and associated coefficients of variation are computed for major industry categories for electricity and natural gas use in small and medium-sized plants in the U.S. The data is very scattered with the coefficients of variation (CoV) often exceeding the average EUI for an energy type. The combined CoV from all of the industries considered, which accounts for 8,200 plants from all areas of the continental U.S., is 290%. This paper discusses EUIs and their variations based on electricity and natural gas consumption. Data from milder climates appears more scattered than that from colder climates. For example, the ratio of the average of coefficient of variations for all industry types in warm versus cold regions of the U.S. varies from 1.1 to 1.7 depending on the energy sources considered. The large data scatter indicates that predictions of energy use obtained by multiplying standard EUI data by plant area may be inaccurate and are less accurate in warmer than colder climates (warmer and colder are determined by annual average temperature weather data). Data scatter may have several explanations, including climate, plant area accounting, the influence of low cost energy and low cost buildings used in the south of the U.S. This analysis uses electricity and natural gas energy consumption and area data of manufacturing plants available in the U.S. Department of Energy's national Industrial Assessment Center (IAC) database. The data there come from Industrial Assessment Centers which employ university engineering students, faculty and staff to perform energy assessments for small to medium-sized manufacturing plants. The nation-wide IAC program is sponsored by the U.S. Department of Energy. A collection of six general energy saving recommendations were also written with Texas manufacturing plants in mind. These are meant to provide an easily accessible starting point for facilities that wish to reduce costs and energy consumption, and are based on common recommendations from the Texas A&M University IAC program.

With gradually increasing interdependence of international political and economic environments, part of Asian countries' financial markets reform adopted progressive policies towards liberalization and internationalization. Therefore, the integration of international financial markets has attracted a bunch of scholars to investigate related topics of international stock market. Granger and (1993) documented that most of the economic variables have nonlinear characters. Chelley-Steeley (2004) uses smooth transition regression model to explore the financial market integration of regional and global markets among emerging and developed countries. Smooth transition regression model considered the possibility of nonlinear changes in regression parameters. This paper applies the smooth transition regression model to reinvestigate Chelley-Steeley¡¦s (2004) study of nonlinear relationship of stock markets among some East Asian countries and the United States, Japan and Germany. The main difference of our model and Chelley-Steeley¡¦ model is that we relax his constant market index correlation between two countries by allowing the autoregressive process on market index correlation. Empirical evidences of linear model, original non-linear model and our non-linear extension model show that our non-linear extension model outperformedthe other two models in terms of goodness of fit.

This paper starts from the single tube condensation theory of shell side inferred by Nusselt , and then analyzes the coefficient of heat transfer of the shell side and the overall heat transfer coefficient of the tube bundle. Referring to the overall heat coefficient of surface condensers and the calculation means of pressure decrease, the HEI, the most exploited one in the commerce is used by combining the basic theory of condenser heat transfer based on the Delphi function language to develop a set of assistant designing software. The software can be used to evaluate the performance of condensers, calculate the sizes of tube materials, and predict the pressure of condensers when the different tube materials are used. When the units are in using, this software also can calculate the cleanliness factor and determine the suitable time to clean the condenser tubes. There are four common used tube materials to compare their performance. They are Al- Brass tubes, 70-30 Cu-Ni tubes, Sea-Cure tubes and Ti tubes. This paper use the software to analyze the performance of the heat transfer of these four different kinds of tube materials and also to calculate the sizes of tubes .And use research papers to analyze the reason of anti-corrosion of these four. In addition, the HEI method can analyze the anti-vibration ability of these four. After comparing with all the performance of the tube materials, and then choosing the best tube material to provide an example for condenser design of new electricity plants or for old electricity plants to change the tube materials.

Diffusion behavior of spin cast polymer thin films was studied in detail as a function of film thickness. Diffusion coefficients of water molecules in poly(methyl methacrylate) (PMMA) were found to decrease from 10-8 cm2/s in thick films to 10-13 cm2/s in ultra-thin films. In order to probe if there is a characteristic length scale set by the polymer chain size, the effect of PMMA molecular weights on this behavior was tested and deviation of diffusion coefficient from bulk was observed in all molecular weights of PMMA investigated. Diffusion coefficients in these films was also studied as a function of aging time at 25°C and was not found to change significantly over a time period of approximately four months. The impact of residual casting solvent in thick and thin films was studied and found to have no influence in the diffusion behavior. Positron Annihilation Lifetime Spectroscopy (PALs) was used to probe the free volume (FV) pocket size and its distribution within the film as a function of film thickness in PMMA. Decrease in FV pocket size was found to be one of the general underlying causes for such thickness dependent diffusion behavior observed in thin polymer films. In addition, Protracted Colored Noise Dynamics (PCND) that enables efficient sampling of phase space and faster relaxation of the systems compared to Molecular Dynamics (MD) was investigated for its extensibility to three dimensional systems and was found to be sensitive to initial conformation.

Thèse de doctorat : Procédés biotechnologiques et alimentaires : INPL : 2007. / Titre provenant de l'écran-titre.

Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 80-86). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 80-86). Also available on the Internet.