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Annular flow is an important flow regime in many industrial applications. The need for a better understanding of this flow regime is driven by the desire to improve the design of many terrestrial and space-based systems. Annular two-phase flow is frequently present in the drilling, production and transportation of oil and natural gas, boilers and condensers, and in heating and refrigeration systems. The flow regime is also important for the refueling of space vehicles, and heating and refrigeration systems for space use. Past studies on annular flow have dealt with varying the gas or liquid Reynolds numbers and studying the effect of such changes on the flow regimes and pressure drops. The effect of two other relevant dimensionless groups, namely the gas-to-liquid density ratio and the gas-to-liquid viscosity ratio, on the film characteristics are noticeably absent. As well, with the increased interest in the space environment, studies on the effect of the gravitational acceleration on two-phase flow would be beneficial. The effect of the gas density and the gravitational acceleration on the annular flow average film thickness and frictional pressure drop are examined. The film thickness was measured using two-wire conductance probes. Experimental data were collected in microgravity and hypergravity aboard the Novespace Zero-G Airbus microgravity simulator and normal gravity data were collected at the University of Saskatchewan. Data were collected for a range of annular flow set points by changing the liquid and gas mass flow rates. The liquid-to-gas density ratio was examined by collecting annular flow data using helium-water and air-water. The gravitational effect on the film thickness characteristics was examined by collecting the data during the microgravity and pull-up (hypergravity) portions of each parabolic flight. A direct comparison is possible between the normal gravity data and the microgravity data, due to the matching of the liquid and gas mass flow rates and the flow regime. The reduction in gravity causes the average film thickness to increase between two and four times from the normal gravity values. The microgravity average frictional pressure drop is within approximately 20% of the normal gravity pressure drop for the same flow conditions. For all gravity levels, the air-water and the helium-water flows give similar results, for both average film thickness and frictional pressure drop, when based on the specific energy of the gas. The hypergravity average film thickness results are larger than at normal gravity for the same flow conditions. However, no flow regime map exists for the hypergravity condition, so the similarity of the flow regime cannot be confirmed. The hypergravity flow appears more chaotic, and may be in the transition from a churn type flow. The average frictional pressure drop is increased by approximately 20% due to the increase in the gravitational acceleration. New non-dimensional equations, which include the effect of the gas density, are presented for each gravity level to predict the average film thickness and the average frictional pressure drop.

This thesis describes a fundamental study of the miscibility and the nature of the interface between components of core-shell polymer blends using the technique of Fluorescence Resonance Energy Transfer (FRET) coupled with data analysis that involves Monte-Carlo simulations. Our aim in this study was to develop a fundamental methodology to quantitatively determine the width of the interface between the two components in binary polymer blends. At the current state of the art, data analysis of FRET experiments requires translational symmetry. In the system under study, uniform core-shell structures satisfy this criterion. Thus, in this work our focus was directed toward the study of a blend system with a core-shell structure. For this FRET study, I have identified a number of potential donor and acceptor dye pairs that fluoresce in the visible range of the spectrum and can be chemically attached to polymers. Among them, I selected, as the donor and the acceptor, a pair of naphthalimide dyes that have not previously been used for FRET experiments. Model experiments showed that while the fluorescence decay profile of the donor chromophore was exponential in solution, it was not exponential in polystyrene (PS) or poly(methyl methacrylate) (PMMA) films. Thus, I carried out refinements to existing FRET theory to interpret the data generated by using these dyes. Also, I derived a new model to predict the fluorescence intensity of non-exponential decaying donor dyes in core-shell systems. I selected a model system composed of a PS core surrounded by a PMMA shell. The PS core particles were prepared by miniemulsion polymerization to obtain cross-linked PS particles with a narrow size distribution. Seeded emulsion polymerization under starved-fed condition was employed to synthesize monodisperse dye-labeled core-shell particles. The extent of miscibility and the nature of interface between the core and the shell polymers were retrieved from a combined study by Monte-Carlo simulations and analysis of the donor fluorescence intensity decays. Agreement between the retrieved interface thickness and the literature data on PS-PMMA validates the methodology developed here for the use of such donor dyes in FRET studies on polymer blends.

We examine the formation of sets homeomorphic to the ternary Cantor set by continued radicals. We determine properties of bridges and gaps and calculate the thickness of the Cantor set. From this we apply information from continued fractions to continued radicals to obtain new results. We also consider the measure of several Cantor sets.

At the age of multi-media, portable electronic devices such as mobile phones, personal digital assistant and handheld gaming systems have increased the demand for high performance displays with low cost production. Inkjet printing color optical filters (COF) for LCD applications seem to be an interesting alternative to decrease the production costs. The advantage of inkjet printing technology is to be fast, accurate, easy to run and cheaper than other technologies. In this master thesis work, we used various disciplines such as optical microscopy, rheology, inkjet printing, profilometering and colorimetry. The specific aim of the thesis was to investigate the feasibility of using company-A pigment formulation in inkjet production of COF for active matrix LCD applications. Ideal viscosity parameters were determined from 10 to 20mPa·s for easy inkjet printing at room temperature. The red pigments used are fully dispersed into the solvent and present an excellent homogenous repartition after printing. Thickness investigations revealed that the printed COF were equal or slightly thicker than typically manufactured ones. The colorimetry investigations demonstrated color coordinates very close to the NTSC red standard. LED backlighting seems to be a valuable solution to combine with the printed COF regarding to the spectrum and color analysis. The results on this thesis will increase the understanding of inkjet printing company-A pigments to produce COF for LCD applications.

Annular flow is an important flow regime in many industrial applications. The need for a better understanding of this flow regime is driven by the desire to improve the design of many terrestrial and space-based systems. Annular two-phase flow is frequently present in the drilling, production and transportation of oil and natural gas, boilers and condensers, and in heating and refrigeration systems. The flow regime is also important for the refueling of space vehicles, and heating and refrigeration systems for space use. Past studies on annular flow have dealt with varying the gas or liquid Reynolds numbers and studying the effect of such changes on the flow regimes and pressure drops. The effect of two other relevant dimensionless groups, namely the gas-to-liquid density ratio and the gas-to-liquid viscosity ratio, on the film characteristics are noticeably absent. As well, with the increased interest in the space environment, studies on the effect of the gravitational acceleration on two-phase flow would be beneficial. The effect of the gas density and the gravitational acceleration on the annular flow average film thickness and frictional pressure drop are examined. The film thickness was measured using two-wire conductance probes. Experimental data were collected in microgravity and hypergravity aboard the Novespace Zero-G Airbus microgravity simulator and normal gravity data were collected at the University of Saskatchewan. Data were collected for a range of annular flow set points by changing the liquid and gas mass flow rates. The liquid-to-gas density ratio was examined by collecting annular flow data using helium-water and air-water. The gravitational effect on the film thickness characteristics was examined by collecting the data during the microgravity and pull-up (hypergravity) portions of each parabolic flight. A direct comparison is possible between the normal gravity data and the microgravity data, due to the matching of the liquid and gas mass flow rates and the flow regime. The reduction in gravity causes the average film thickness to increase between two and four times from the normal gravity values. The microgravity average frictional pressure drop is within approximately 20% of the normal gravity pressure drop for the same flow conditions. For all gravity levels, the air-water and the helium-water flows give similar results, for both average film thickness and frictional pressure drop, when based on the specific energy of the gas. The hypergravity average film thickness results are larger than at normal gravity for the same flow conditions. However, no flow regime map exists for the hypergravity condition, so the similarity of the flow regime cannot be confirmed. The hypergravity flow appears more chaotic, and may be in the transition from a churn type flow. The average frictional pressure drop is increased by approximately 20% due to the increase in the gravitational acceleration. New non-dimensional equations, which include the effect of the gas density, are presented for each gravity level to predict the average film thickness and the average frictional pressure drop.

Purpose: To investigate whether retinal thickness varies with refractive error. Also secondary to see if there is any difference in retinal thickness between the right and left eye. Methods: The inclusion criteria for the study was subjects without any pathologies, age between 18-45 and refractive error of maximum +0.75 SER and the myopia had no limit, as well as no astigmatism higher then -1.00D. Subjects, which fitted the inclusion criteria for the study, was shown to the OCT room were retinal thickness measurements were acquired first on the right and then left eye. To get the same reading area, the same setup was used and the fixation point was always centered for each patient. After all subjects had undergone the same method the results were analyzed using t-test and regression analysis. Results: The analysis showed a difference between emmetropic eyes and myopic eyes in the peripheral retinal thickness, having the myopes being significantly thinner. The inter myopic analysis showed no difference in retinal thickness in any of the points. This could however be due to the smaller sample size. The comparison between right and left eye showed a good symmetry between the two eyes both in the emmetropic and the myopic group. Conclusions: From this study we can conclude that the myopic group has a thinner peripheral retinal thickness than the emmetropic group. Central retinal thickness is not significantly different but could be due to the smaller sample size. There is no difference in retinal thickness between right and left eye.

Ultrathin graphite films, with thickness from 1-30 atomic layers, are grown on the Si-terminated and C-terminated faces of 6H-SiC and 4H-SiC via thermal desorption of silicon in an ultrahigh vacuum (UHV) chamber or in a high-vacuum RF furnace. Graphite LEED patterns and atom-resolved STM images on graphite films prove that epitaxial growth is achieved on both faces of the SiC substrate. The thickness of graphite films is estimated with modeling the Si:C Auger peak intensities. Through LEED and STM investigations of monolayer graphite grown on the Si-face of SiC(0001) surface, we show the existence of a SiC 6R3*6R3 reconstructed layer between graphite films and the SiC substrate. The complicated LEED patterns can be interpreted partially by the kinematic scattering of the interfacial layer and the 6*6 surface corrugation. Further scanning tunneling spectroscopy (STS) measurements indicate that the graphite films remain continuous over the steps between domains. Carbon nanotubes and carbon nanocaps cover about 40% of the graphitized C-face of SiC. The remaining areas are flat graphite films. Graphite ribbons were made through E-beam lithography. After the lithography process, the graphitic features remain on flat region underneath HSQ residues.

The aim of this study was to explore the properties of thermal field in spray cooling via experiments. The nozzle diameter (dj) used herein was 200 £gm and the heating surface measured 45 mm ¡Ñ 45 mm. The study was divided into two parts for experiments and analyses. In the first part, with DI water and FC-72 (dielectric liquid) as the working media, the changes in the liquid film thickness on the heater surface under different values of heating power were observed; heat input (Q) and value of gauge pressure (£GP) were taken as the main parameters for discussing the influence of these two parameters on the liquid film thickness in spray cooling. The second part, with DI water as the working medium, adopted the £gLIF system (fluorescent dye: Rhodamine B; concentration: 1.5¡Ñ10-4 M) to measure the effect of different working medium temperatures (23 ¢XC, 30 ¢XC, and 40 ¢XC) on the global temperature distribution, liquid film temperature changes on the heater surface and the thermal field condition of spray cooling, with an aim of exploring the internal physical phenomena of the droplets during cooling.

The cerebral cortex is gray matter tissue which covers cerebral hemispheres. In recent years, many studies reported that abnormal cortical thickness was found in several diseases of central neural system, such as multiple sclerosis, Alzheimer's diseases, and schizophrenia. Therefore, the whole-brain measurement of cortical thickness using the non-invasive magnetic resonance imaging becomes important. However, not many algorithms were reported in the past due to the extremely complex folding structure of human cortex. In this thesis, a voxel-based cortical thickness method proposed by Hutton et al was implemented using MATLAB to achieve automated measurement. Several crucial factors, including the definition of boundary condition, interpolation method, the step size of developing each streamline, and spatial resolution of imaging space, in the implementation were discussed. In addition, the analysis of stability, or precision, of our self-developed program was evaluated . Sixteen experiments of reproducibility were performed in two months on the same 24-year-old healthy volunteer repeatedly to obtain whole-brain 3D T1WI. Cortical thickness map was calculated independently and normalized to the same coordination. Mean, standard deviation, and normalized standard deviation of 16 measurements were calculated on every cortical voxel, along with whole-brain mean cortical thickness. Various sizes of 3D smoothing kernel were applied, and the results showed stronger smoothing might help higher precision by the cost of spatial resolution.