Dissertations / Theses on the topic 'Partial thickness'

Rotator cuff disorders encompass a range of impairments from tendinopathy to partialor full-thickness rotator cuff tears, and represent the largest subgroup of shoulder pain. Rotator cuff tears, most of which are atraumatic, are common in adults with shoulder pain and are strongly associated with increasing age. Conservative treatment including physiotherapy is the first-line treatment, but some patients do not respond, and ultimately require surgery. Early predictions of response could allow individuals’ care pathways to be optimised, preventing unnecessary delays and suffering and benefiting patients and healthcare providers alike. My primary aim was to develop a prognostic model for the outcome of physiotherapy in adults with painful atraumatic partial-thickness tears (PTTs) of the rotator cuff. This was addressed by a prospective prognostic model study. The study was underpinned by a systematic review of prognostic models in adults undergoing physiotherapy for painful rotator cuff disorders and was further informed and complemented by the following work: the development and validation of the physiotherapy protocol for the prognostic study; the identification, selection and definition of the candidate prognostic factors for the prognostic study; the estimation of the Minimal Important Difference (MID) of the study’s primary outcome measure (the Western Ontario Rotator Cuff Index, WORC); and an exploratory responder analysis of the WORC outcome scores. The prognostic systematic review, prognostic study, MID analysis and responder analysis are original contributions to knowledge. The prognostic systematic review revealed important methodological deficiencies in the five included studies, and no clinically usable model. No study addressed a distinct PTT population. The process of identifying factors for my own prognostic model study revealed a lack of knowledge about the prognostic relevance of factors. All of the candidate models I explored in my prognostic study (n sample = 65, n analysed = 61) had low performance and precision. The estimated MID of the WORC was -300. The responder analysis resulted in different proportions of responders to treatment depending on the responder definition. My results highlight the difficulties involved in predicting outcomes in the field of shoulder pain and rotator cuff disorders, and the need for methodologically sound prognosis research.

The effect of near work on the biometric properties of the eye, including the eye’s length and the thickness of the posterior vascular layer were investigated. Short-sighted eyes had greater increases in length and greater thinning of the vascular layer when focused on close objects than did normally-sighted eyes. These changes occurred across the horizontal meridian of the eye and were greatest at the posterior pole. These ocular effects of focusing may partly explain the influence of close work on development of short-sightedness.

Wound healing is a complex process, in which a sequence of interrelated events at both the cell and tissue levels interact and contribute to the reduction in wound size. For diabetic patients, many of these processes are compromised, so that wound healing slows down and in some cases halts. In this thesis we develop a series of increasingly detailed mathematical models to describe and investigate healing of full thickness skin wounds. We begin by developing a time-dependent ordinary differential equation model. This phenomenological model focusses on the main processes contributing to closure of a full thickness wound: proliferation in the epidermis and growth and contraction in the dermis. Model simulations suggest that the relative contributions of growth and contraction to healing of the dermis are altered in diabetic wounds. We investigate further the balance between growth and contraction by developing a more detailed, spatially-resolved model using continuum mechanics. Due to the initial large retraction of the wound edge upon injury, we adopt a non-linear elastic framework. Morphoelasticity theory is applied, with the total deformation of the material decomposed into an addition of mass and an elastic response. We use the model to investigate how interactions between growth and stress influence dermal wound healing. The model reveals that contraction alone generates unrealistically high tension in the dermal tissue and, hence, volumetric growth must contribute to healing. We show that, in the simplified case of homogeneous growth, the tissue must grow anisotropically in order to reduce the size of the wound and we postulate mechanosensitive growth laws consistent with this result. After closure the surrounding tissue remodels, returning to its residually stressed state. We identify the steady state growth profile associated with this remodelled state. The model is used to predict the outcome of rewounding experiments as a method of quantifying the amount of stress in the tissue and the application of pressure treatments to control tissue synthesis. The thesis concludes with an extension to the spatially-resolved mechanical model to account for the effects of the biochemical environment. Partial differential equations describing the dynamics of fibroblasts and a regulating growth factor are coupled to equations for the tissue mechanics, described in the morphoelastic framework. By accounting for biomechanical and biochemical stimuli the model allows us to formulate mechanistic laws for growth and contraction. We explore how disruption of mechanical and chemical feedback can lead to abnormal wound healing and use the model to identify specific treatments for normalising healing in these cases.

Friction stir welding (FSW) of steel is often performed with an insert made of polycrystalline cubic boron nitride (PCBN). Specifically, MS80 is a grade of PCBN made by Smith MegaDiamond that has been optimized for the FSW process. The PCBN insert is attached to a tungsten carbide (WC) shank by a compression fitting. However, FSW tools manufactured by this method inevitably fail by fracture in the PCBN. Permanently bonding PCBN to WC would likely solve the fracturing problem and increase the life of PCBN FSW tools to be economically viable. Partial transient liquid phase (PTLP) bonding, a process used to join ceramics with thin metallic interlayers, was proposed as a method to permanently bond PCBN to WC. PTLP bonding is often performed using three layers of pure elements. On heating, the two thin outer interlayers melt and bond to the ceramics. Concurrently, these liquid layers diffuse into the thicker refractory core until solidification has occurred isothermally. A procedure was developed to reduce the number of possible three-layer PTLP bonding setups to a small set of ideal setups using logical filters. Steps in this filtering method include a database of all existing binary systems, sessile drop testing of 20 elements, and a routine that calculates maximum interlayer thicknesses. Results of sessile drop testing showed that the PCBN grade required for this research could only be bonded with an alloy of Ti, Cu, Mg, and Sb. Two PTLP bond setups were tested using this special coating on the PCBN, but a successful bond could not be achieved. However, a PTLP bond of WC to WC was successful and proved the usefulness of the filtering procedure for determining PTLP bond setups. This filtering procedure is then set forth in generalized terms that can be used to PTLP bond any material. Also, recommendations for future research to bond this grade of PCBN, or some other grade, to WC are presented.

There is an urgent need to develop ammonia removal treatment systems for municipal and industrial wastewater treatment due to the increasingly stringent ammonia effluent discharge regulations implemented by Canada, the United States, and the European Union. The objective of this dissertation is to develop new understanding and advance the current design and operation of total ammonia nitrogen (TAN) removal via the moving bed biofilm reactor technology (MBBR) for municipal and industrial wastewaters. The first specific objective is to develop a passive, low operationally intensive, efficient and robust design strategy for municipal wastewater treatment to achieve partial nitritation (PN) as a pre-treatment to anammox treatment without using control strategies such as operating at low dissolved oxygen, or the use of inhibitors. This first objective includes developing new knowledge of the biofilm, biomass and microbiome of attached growth PN systems. The second specific objective is to investigate the impact of defining a maximum biofilm thickness, via bio-carrier design, to enhance the effects of free nitrous acid inhibition for PN of municipal wastewaters. The third objective is to investigate the effect of influent copper concentration on nitrifying MBBR systems over long-term operations, to demonstrate the feasibility of the nitrifying MBBR as a solution for TAN removal from gold mining wastewaters. The results pertaining to the first objective, achieved via a study investigating the operation of a nitrifying moving bed biofilm reactor at elevated TAN surface area loading rates (SALRs) of 3, 4, 5, and 6.5 g TAN/m²∙d with the aim of achieving passive PN, demonstrates that operating at a TAN SALR value of 6.5 g TAN/m²∙d can achieve PN without restricting dissolved oxygen or using inhibitors. Operating at a TAN SALR value of 6.5 g TAN/m²∙d achieves a TAN surface area removal rate (SARR) of 3.5 g TAN/m²∙d, and a nitrite accumulation of 99.8% of the oxidized TAN, demonstrating the suppression of nitrite oxidizing bacteria (NOB) activity, while achieving elevated TAN SARR values. At the molecular-scale, there is a statistically significant change in the ammonia oxidizing bacteria (AOB) to NOB ratio from 1:2.6 to 8.7:1 as the TAN SALR increases from 3 to 6.5 g TAN/m²∙d; however, even at a TAN SALR value of 6.5 g TAN/m²∙d there is an NOB abundance of approximately 2%; thus demonstrating that NOB remain present in the biofilm, while their activity is suppressed by operation at elevated TAN SALR values. Furthermore, this system was shown to achieve stable PN consistently for over a period of 10 months of operation, demonstrating a robust, passive, low operational strategy for attached growth PN. The second objective of this dissertation is addressed through a study that compared the carrier design of defined maximal biofilm thickness (z-prototype carrier) to undefined maximal biofilm thickness (chip-prototype carrier) for PN via free nitrous acid inhibition of tertiary, low carbon, municipal wastewaters. The study demonstrates that defined maximal biofilm thickness is a preferred design choice to achieve attached growth PN. The chip-prototype carrier shows biofilm thicknesses and biofilm mass values that are ten-fold higher than the z-prototype carrier, which is shown to contribute to the impact of free nitrous acid on AOB and NOB activities. The z-prototype carrier shows PN is achieved after 3 hours of exposure to free nitrous acid while the chip-prototype carrier does not achieve PN within this same time of exposure. Therefore, the defined maximal biofilm thickness carrier is identified in this research as the preferred design option to achieve attached growth PN for municipal, low carbon, tertiary wastewater treatment. The results of the third objective, achieved via a study investigating the effects of influent copper concentrations on nitrifying MBBR during long term operations to gold mining wastewaters, demonstrates that there is no AOB inhibition in attached growth systems exposed to 0.1, 0.3, 0.45, and 0.6 mg Cu/L for long exposure times. A trend of increasing nitrite accumulation with increasing influent copper concentrations is shown, indicating that NOB inhibition occurs at influent copper concentrations of 0.3 mg Cu/L and greater, with the greatest NOB inhibition observed with an influent copper concentration of 0.6 mg/L. There is no statistically significant difference in biofilm characteristics at the copper concentrations tested; however, there is a trend of increasing biofilm thickness and biofilm roughness with increasing copper concentrations. This study demonstrates the resilience of the nitrifying biofilm to copper inhibition and demonstrates that the nitrifying MBBR is a promising system for removing TAN in mining wastewater in the presence of copper.

Thesis (M.A.)--University of North Carolina at Chapel Hill, 2007.
Title from electronic title page (viewed Dec. 18, 2007). "... in partial fulfillment of the requirements for the degree of Masters in the Department of Geography (Climatology)." Discipline: Geography; Department/School: Geography.

Les travaux réalisés dans cette thèse se situent à l'interface des domaines de l'acquisition en imagerie par résonance magnétique (IRM) et du traitement d'image pour l'analyse automatique des structures cérébrales. La mesure de modifications structurelles telles que l'atrophie corticale nécessite l'application d'algorithmes de traitement d'image. Ceux-ci doivent compenser les artefacts en IRM tels que l'inhomogénéité du signal ou les effets de volume partiel (VP) pour permettre la segmentation des tissus cérébraux puis l'estimation d'épaisseur corticale. Nous proposons une nouvelle modélisation de VP proche de la physique de l'acquisition baptisée modèle bi-exponentiel qui vient concurrencer le traditionnel modèle linéaire. Il nécessite l'utilisation de deux images de contrastes différents parfaitement recalées. Ce modèle a été validé sur des simulations et des fantômes physique et numérique dans un premier temps. Parallèlement, la récente séquence MP2RAGE permet d'acquérir deux images co-recalées par acquisition et leur combinaison aboutit à l'obtention d'une image insensible aux inhomogénéités du signal et d'une carte de T1 des tissus imagés. Nous avons testé notre modèle sur des données in vivo MP2RAGE et avons montré que l'application du modèle linéaire de VP conduit à une sous-estimation systématique de la substance grise à l'échelle du voxel. Ces erreurs se propagent à l'estimation d'épaisseur corticale, biomarqueur très sensible aux effets de VP. Nos résultats plaident en faveur de l'hypothèse suivante : la modélisation de VP pour les images MP2RAGE doit être différente de celle employée pour des images obtenues avec des séquences plus classiques. Le modèle bi-exponentiel est une solution adaptée à cette séquence particulière
The work developed in this thesis is within the scope of magnetic resonance imaging (MRI) acquisition and image processing for the automated analysis of brain structures. The measurement of structural modifications with time such as cortical atrophy requires the application of image processing algorithms. They must compensate for MRI artifacts such as intensity inhomogeneities or partial volume (PV) effects to allow for brain tissues segmentation then cortical thickness estimation. We suggest a new PV model relying on the physics of acquisition named bi-exponential model that differs from the commonly used linear model by modelling brain tissues and image acquisition. It requires the use of two differently contrasted and perfectly coregistered images. This model has been validated with simulations and physical and digital phantoms in a first place. In parallel, the recent MP2RAGE sequence provides two coregistered images and their combination results in a bias-field corrected image as well as a T1 map of the scanned tissues. We tested our model with in vivo MP2RAGE data and demonstrated that using the linear PV model leads to a systematic gray matter proportion underestimation in PV voxels. These errors result in cortical thickness underestimation. Our results favor the following assumption: PV modelling with MP2RAGE images must differ from the usual linear PV model applied for images obtained from more classic sequences. The bi-exponential model is an adapted solution to this particular sequence

Thesis (Ph.D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008.
Committee Chair: Allen R. Tannenbaum; Committee Member: Anthony J. Yezzi; Committee Member: Gregory Turk; Committee Member: Joel R. Jackson; Committee Member: Patricio A. Vela

The separation of solids from biological wastewater treatment is an important step in the treatment process, as it has a significant impact on effluent water quality. The moving bed biofilm reactor (MBBR) technology is a proven upgrade or replacement wastewater treatment system for carbon and nitrogen removal. However, a challenge of this technology is the characteristics of the effluent solids that results in their poor settlement; with settling being the common method of solids removal. The main objective of this research is to understand and expand the current knowledge on the settling characteristics of MBBR produced solids and the parameters that influence them. In particular, in this dissertation, the impacts are studied of carrier types, biofilm thickness restraint design of carriers, and varying carbonaceous loading rates on MBBR performance, biofilm morphology, biofilm thickness, biofilm mass, biofilm density, biofilm detachment rate, solids production, particle size distribution (PSD) and particle settling velocity distribution (PSVD). With this aim, three MBBR reactors housing three different carrier types were operated with varying loading rates. In order to investigate the effect of carrier geometrical properties on the MBBR system, the conventional, cylindrically-shaped, flat AnoxK™ K5 carrier with protected voids was compared to two newly-designed, saddle-shaped Z-carriers with the fully exposed surface area. Moreover, the AnoxK™ Z-200 carrier was compared to the AnoxK™ Z-400 carrier to evaluate the biofilm thickness restraint design of these carriers, where the Z-200 carrier is designed for greater biofilm thickness-restraint. The Z-200 carrier is designed to limit the biofilm thickness to the level of 200 µm as opposed to 400 µm for the Z-400 carrier. Finally, to investigate the effects of varying carbonaceous loading rates on system removal performance, biofilm characteristics and solids characteristics, further analyses were performed at three different loading rates of 1.5 to 2.5 and 6.0 g-sBOD/m2·d in steady-state conditions. The PSD and the PSVD analyses were combined to relate these two properties. A settling velocity distribution analytical method, the ViCAs, was applied in combination with microscopy imaging and micro-flow imaging to investigate the relation of PSD and settling behaviour of MBBR produced particles. The obtained results have indicated that the carrier type significantly impacted the MBBR performance, biofilm, and particle characteristics. As such, the K5 carrier MBBR system demonstrated a statistically significantly higher carbonaceous removal rate and efficiency (3.8 ± 0.3 g-sBOD/m2·d and 59.9 ± 3.0% sBOD removal), higher biofilm thickness (281.1 ± 8.7 μm), higher biofilm mass per carrier (43.9 ± 1.0 mg), lower biofilm density (65.0 ± 1.5 kg/m3), lower biofilm detachment rate (1.7 ± 0.7 g-TSS/ m2·d) and hence lower solids production (0.7 ± 0.3 g-TSS/d) compared to the two Z-carriers. The Z-carriers' different shape exposes the biofilm to additional shear stress, which could explain why the Z-carriers have thinner and denser biofilm, resulting in higher solids production and lower system performance in comparison with K5. Moreover, the carrier type was also observed to impact the particle characteristics significantly. PSD analysis demonstrated a higher percentage of small particles in the Z-carrier system effluent and hence a significantly lower solids settling efficiency. Therefore, the solids produced in the K5 reactor have shown enhanced settling behaviour, consisting of larger particles with faster settling velocities compared to Z-carriers. This dissertation also investigated the effects of restraint biofilm thickness on MBBR performance by comparing the Z-200 biofilm thickness-restraint carrier to the Z-400 carrier. No significant difference was observed in removal efficiency, biofilm morphology, biofilm density, biofilm detachment rate, and solids production between the Z-200 to the Z-400 carriers. The PSD and the PSVD analyses did not illustrate any significant difference in the particles’ settling behaviour for these two biofilm thickness restraint carriers, indicating that the biofilm thickness-restraint carrier design was not a controlling factor in the settling potential of MBBR produced solids. Finally, this research studied the effect of varying loading rates and demonstrated a positive, strong linear correlation between the measured sBOD loading rate and the removal rate, indicating first-order BOD removal kinetics. The biofilm thickness, biofilm density and biofilm mass decreased when the surface area loading rate (SALR) was increased from 2.5 to 6.0 g-sBOD/m2·d. The solids retention time (SRT) was also shown to decrease by increasing the SALR, where the lowest SRT (1.7 ± 0.1 days) was observed at the highest SALR, with the highest cell viability (81.8 ± 1.7%). Significantly higher biofilm detachment rate and yield were observed at SALR 2.5, with the thickest biofilm and a higher percentage of dead cells. Consequently, a higher fraction of larger and rapidly settling particles was observed at SALR of 2.5 g-sBOD/m2·d, which leads to a significantly better settling behaviour of the MBBR effluent solids. This study expands the current knowledge of MBBR-produced particle characteristics and settling behaviour. A comprehensive understanding of the MBBR system performance and the potential influencing factors on the MBBR produced solids, particle characteristics, and their settleability will lead to optimized MBBR design for future pilot- and full-scale applications of the MBBR.

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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Concrete, the major construction material used in the civil industry worldwide, displays remarkable performance and economic benefits. Yet, it also presents a huge environmental impact producing about 7% of the global carbon dioxide (CO2). Given the rise of global warming concerns, studies have been focusing on alternatives to reduce the amount of Portland cement (PC), which is the least sustainable ingredient of the mixture, for example by adopting particle packing model (PPM) techniques. Although a promising alternative, there is currently a lack of studies regarding the efficiently use of PPMs to reduce PC without compromising the fresh and hardened properties of the material. This work appraises the influence of PPMs and advanced mix-design techniques on the fresh (rheological behaviour) and hardened (compressive strength, modulus of elasticity, porosity, and permeability) state behaviours of systems with reduced amount of PC, the so-called low cement content (LCC) concrete. Results show that is possible to produce eco-efficient concrete maintaining and/or enhancing fresh and hardened properties of the material. Nevertheless, further durability and long-term behaviour must be performed on LCC systems.

Concrete, the second most used material in the world, presents great performance and economic benefits. Yet, it is often characterized by a brittle behaviour, low tensile strength, and toughness. Fibers are usually added to concrete to counteract its brittle behaviour, increasing ductility and toughness, controlling crack propagation and delaying concrete failure. However, their addition significantly worsens the fresh state performance of the material. To improve fresh state of the so-called Fiber Reinforced Concrete (FRC), conventional mix-design methods recommend the use of high paste content, which results in a significant increase of Portland cement (PC) content and raises the carbon footprint of the material. The latter is responsible for 8% of the global annual carbon dioxide (CO2) anthropogenic emissions. Given the current worldwide concerns on global warming, the construction industry is in a need to lessen the demand, and thus production of PC. Recent studies have been focusing on the use of advanced mix-design techniques (i.e. particle packing models- PPMs) along with Inert Fillers (IF) as an alternative to reduce PC content in concrete. However, the latter was not applied to conventional FRC. In this work, advanced mix design techniques (i.e. PPMs) are used to overcome the aforementioned issues and mix-proportion eco-efficient FRC with low cement content (< 300 kg/m3). Fresh (i.e. VeBe time, slump, rheological behaviour) and hardened (i.e. compressive strength, and flexural behaviour) state tests were performed on the proposed mixtures and compared with control high PC content (375 kg/m3) FRC mixes. Results show that PPM designed mixes presented higher minimum torque (yield stress) but quite comparable apparent viscositiy when compared to conventionally designed mixtures. Moreover, the flowability (i.e. VeBe time, and slump) tends to decrease as fiber content, length, and/or as the amount of fillers increase in the mixtures. In addition, PPM mixes exhibited a shear thinning behaviour following the Herschel-Bulkley model, which enables the design of FRC PPM mix-proportioned mixtures for applications requiring high torque regimes such as vibrated and/or pumped concrete. Finally, results show that the use of PPMs to mix proportion eco-efficient low cement FRC mixtures produced improved hardened (i.e. compressive strength, and flexural performance) state behaviour with lower environmental impact than conventional ACI designed FRC mixtures.

Dans cette étude, les cratères partiellement enterrés dans la maria lunaire et dans les plaines lisses septentrionales de Mercure ont été identifiés à l'aide de données récemment acquises concernant l'optique, l'élévation et la composition, et les épaisseurs de coulées de lave proches des cratères partiellement enterrés ont été estimées par modélisation numérique de leur dégradation topographique. Au chapitre 1, je présente d'abord le contexte géologique des plaines volcaniques de la Lune et de Mercure. Ensuite, je vais résumer toutes les méthodes qui ont été utilisées pour estimer l’épaisseur des coulées de lave sur la Lune et Mercure, ainsi que les progrès de la recherche sur la dégradation topographique du cratère. Au chapitre 2, je présente les ensembles de données de télédétection utilisés dans cette étude. Ensuite, les critères utilisés pour identifier les cratères partiellement enterrés sont discutés. Une méthode d'estimation de l'épaisseur des coulées de lave est proposée ultérieurement, basée sur la dégradation topographique de cratères partiellement enterrés. L'épaisseur de coulée de lave la mieux adaptée a ensuite été déterminée en minimisant la différence entre le profil final modélisé et le profil observé. Au chapitre 3, afin de résoudre l'équation de diffusion topographique, le profil d'altitude d'un nouveau cratère d'impact est construit comme condition initiale. Pour les cratères d’impact frais lunaires, nous avons construit un ensemble de profils topographiques qui prennent en compte à la fois la taille des cratères et les types de cibles. Pour les nouveaux cratères d’impact sur Mercure, nous avons construit des profils topographiques qui incluent uniquement des cratères de transition et complexes. Comme décrit au chapitre 4, les épaisseurs de basalte ont été inversées en utilisant 41 cratères de maria dont les bords sont complètement exposés. Le résultat montre que les épaisseurs estimées en basalte mare varient de 33 à 455 m, avec une valeur médiane de 105 m. Nous avons ensuite calculé le volume total et le taux d'éruption des basaltes des maria lunaires et avons constaté que le taux estimé d'éruption des basaltes des maria atteignait un sommet de 3,4 Ga, puis diminuait avec le temps, indiquant un refroidissement progressif de l'intérieur de la lune. Nous avons également constaté que la diffusivité topographique des cratères lunaires augmente avec le diamètre et est presque invariante dans le temps. Au chapitre 5, je présente un résultat similaire pour Mercure. Les épaisseurs de coulées de lave ont été inversées pour 17 cratères dont les bords ont été exposés et enduits de plus de 50% de leur circonférence. Le résultat montre que les épaisseurs de coulées de lave varient de 7 à 419 m, avec une valeur médiane de 218 m. Nous avons ensuite calculé le volume total et le taux d’éruption des coulées de lave. En comparant la diffusivité topographique sur la Lune à celle sur Mercure, on peut constater que les deux valeurs sont similaires. Comme indiqué au chapitre 6, il reste quelques problèmes à résoudre à l'avenir. Tout d'abord, j'ai utilisé une géométrie axisymétrique simple lors de la résolution analytique de l'équation de diffusion topographique et n'ai pas envisagé un processus de dégradation topographique entièrement tridimensionnel. Deuxièmement, les diffusivités topographiques inversées présentent un large intervalle d’incertitude et ne sont pas bien contraintes. Troisièmement, les cratères complexes ont généralement un mécanisme de formation compliqué et un fond géologique et une morphologie de cratère variables, ce qui entraîne une variabilité et une incertitude considérables des relations morphométriques du cratère
In this study, partially buried craters on the lunar maria and the northern smooth plains of Mercury were identified using recently acquired optical, elevation, and composition data, and lava flow thicknesses near partially buried craters were estimated by numerically modeling their topographic degradation. In Chapter 1, I first introduce the geologic background of the volcanic plains on the Moon and Mercury. Next, I will summarize all the methods that have been used to estimate the lava flow thicknesses on the Moon and Mercury, as well as the research progress on the crater topographic degradation. In Chapter 2, I present the remote sensing datasets used in this study. Then, the criteria used to identify partially buried craters are discussed. A lava flow thickness estimation method is later proposed based on the topographic degradation of partially buried craters. The best fitting lava flow thickness was then determined by minimizing the difference between the modeled final profile and the observed profile. In Chapter 3, in order to solve the topographic diffusion equation, the elevation profile of a fresh impact crater is constructed as the initial condition. For lunar fresh impact craters, we constructed a set of topographic profiles that consider both crater sizes and target types. For fresh impact craters on Mercury, we constructed topographic profiles that only include transitional and complex craters. As described in Chapter 4, the basalt thicknesses were inverted using 41 mare craters whose rims are completely exposed. The result shows that the estimated mare basalt thicknesses vary from 33 to 455 m, with a median value of 105 m. We then calculated the total volume and eruption rate of lunar mare basalts, and found that the estimated eruption rate of mare basalts peaked at 3.4 Ga and then decreased with time, indicating a progressive cooling of the lunar interior. We also found that the topographic diffusivity of lunar craters increases with diameter and is almost invariant with time. In Chapter 5, I present a similar result for Mercury. The lava flow thicknesses were inverted for 17 craters whose rims were exposed and embayed for more than 50% of its circumference. The result shows that the lava flow thicknesses vary from 7 to 419 m, with a median value of 218 m. We then calculated the total volume and eruption rate of the lava flows. Comparing the topographic diffusivity on the Moon with that on Mercury, it can be found that both values are similar to each other. As shown in Chapter 6, there are some remaining issues that need to be solved in the future. First, I employed a simple axisymmetric geometry when analytically solving the topographic diffusion equation and did not consider a fully three-dimensional topographic degradation process. Second, the inverted topographic diffusivities have a large range of uncertainty and are not well constrained. Third, complex craters usually have complicated formation mechanism and a variable geologic background and crater morphology, resulting in considerable variability and uncertainty in the crater morphometric relations

碩士
國立清華大學
工業工程與工程管理學系
104
In a highly competitive and capital-intensive industry, such as panel industry. To keep its competitive advantage, panel industry try to use the halftone mask into the process. Using halftone mask reduce the process flow into four. However, halftone mask easily lead to resist non-uniformity, these make panel industry need to control the resist uniformity to make sure that product quality is fine. Considering the cost of time and equipmetn, industry always use sampling to monitor the product quality, but sampling does not guarantee total quality management. In this study, we collect history data, using partial least squares to construct a virtual metrology framework to predict the halftone thickness. After the prediction model is built, not only reduce the frequency of measuring but help panel industry to inspect the whole production equipment, react deviant problem and reduce product cycle time then achieve high capacity goals. By cooperating with a well-known Taiwanese panel company to test the method validity and the MAPE of the validation data set was 3.96%, means a good representative of the prediction model.

碩士
國立交通大學
環境工程所
91
An analytical model for the constant-flux pumping test is developed for a partially penetrating well that has a finite thickness skin. The Laplace-domain solution is derived by using the Laplace transforms with respect to time and the finite Fourier cosine transforms with respect to the vertical coordinate. This solution is used to produce the curves of dimensionless drawdown versus dimensionless time to investigate the influence of finite thickness skin and partial penetration on the hydraulic head distributions. Under the uniform medium and partially penetrating well conditions, a new time-domain solution is developed by using the Laplace transforms and the Bromwich integral method. A numerical approach including a root search approach, the Gaussian quadrature, and the Shanks method is chosen for evaluating this solution. The Shanks transform served as an acceleration method that can effectively reduce the computing time when evaluating the infinite cosine series. The effect of partial penetration is apparent if the test well is partially penetrated. The aquifer thickness can be assumed to be infinite if it is about 100 times greater than the well-screen length.

A dissertation submitted to the Faculty of Health Sciences, University of the Witwatersrand, in fulfilment of the requirements for the degree of Doctorate of Philosophy.
Senecio serratuloides is widely used for wound healing in South Africa but minimal information regarding its efficacy is available. Furthermore toxic pyrrolizidine alkaloids may be present. The following investigation sought firstly to evaluate the efficacy and safety of Senecio serratuloides in a porcine wound model; secondly to assess for a potential mechanism and finally isolate and identify fractions in in-vitro assays. Assessment of Efficacy and Safety Materials and Methods: Deep partial thickness and full thickness wounds were created on 9 pigs. Treatment included an occlusive dressing (negative control), activated carbon, or the Senecio preparation. Wounds were monitored using photographic documentation, pH measurement and histological analysis (skin thickness and collagen content). Toxicity was monitored on blood and liver samples. Results and Discussion: Efficacy of Senecio serratuloides was established with a significantly thicker epidermis, maximal at day 7 post-operative, 2 days before the controls. Effects on collagen content was negligible with no toxicity detected. Mechanistic investigation Materials and Methods: Wound fluid was analysed for IL-10, IL-12, IL-1β, IL-6, IL-8, TNF-α using flow cytometry based assays. Tyrosine phosphorylation and cellular proliferation was assessed using dual immunofluorescence staining. Results and Discussion: IL-1β levels were significantly greater in the Senecio treatment. Tyrosine phosphorylation increased to day 9 post-operative where it stabilised in all groups. In the same period, cellular proliferation was sustained in the Senecio treated wounds but not in the controls. Keratinocyte proliferation was identified as the target for in-vitro assays. Extraction, Isolation and Partial Identification using In-vitro Proliferation Assays. Materials and Methods: The plant was fractionated using solid phase extraction cartridges. Keratinocytes were grown under standard conditions in 96-well plates. Cellular proliferation was assessed spectrophotometrically using a resazurin dye technique. Active fractions were analysed using gas chromatography and mass spectrometry. Results and Discussion: Identified fractions increased the rate of proliferation by 300- 400%. Potential lead compounds were identified. Importantly, pyrrolizidine alkaloids could not be detected. Conclusion Senecio serratuloides is efficacious in treating deep partial thickness wounds without inducing liver toxicity. Sustained keratinocyte proliferation linked to tyrosine phosphorylation may be an underlying mechanism. Although successful, in-vitro detection of active fractions requires further characterisation.

no
PURPOSE: To estimate refractive indices used by the Lenstar biometer to translate measured optical path lengths into geometrical path lengths within the eye. METHODS: Axial lengths of model eyes were determined using the IOLMaster and Lenstar biometers; comparing those lengths gave an overall eye refractive index estimate for the Lenstar. Using the Lenstar Graphical User Interface, we noticed that boundaries between media could be manipulated and opposite changes in optical path lengths on either side of the boundary could be introduced. Those ratios were combined with the overall eye refractive index to estimate separate refractive indices. Furthermore, Haag-Streit provided us with a template to obtain 'air thicknesses' to compare with geometrical distances. RESULTS: The axial length estimates obtained using the IOLMaster and the Lenstar agreed to within 0.01 mm. Estimates of group refractive indices used in the Lenstar were 1.340, 1.341, 1.415, and 1.354 for cornea, aqueous, lens, and overall eye, respectively. Those refractive indices did not match those of schematic eyes, but were close in the cases of aqueous and lens. Linear equations relating air thicknesses to geometrical thicknesses were consistent with our findings. CONCLUSION: The Lenstar uses different refractive indices for different ocular media. Some of the refractive indices, such as that for the cornea, are not physiological; therefore, it is likely that the calibrations in the instrument correspond to instrument-specific corrections and are not the real optical path lengths.

碩士
國立臺灣大學
化學工程學研究所
106
An analytical study is presented for the diffusiophoretic motion of a charged colloidal sphere located at the center of a charged spherical cavity filled with an electrolyte solution at the quasisteady state for the case of arbitrary electric double layers. The electrokinetic equations governing the ionic concentration, electric potential, and velocity distributions in the fluid phase are linearized by assuming that the system is only slightly distorted from equilibrium. These linearized equations are solved by using a perturbation method with the zeta potentials of the particle and cavity as the small perturbation parameters. An explicit formula for the diffusiophoretic velocity of the particle as a combination of the electrophoretic and chemiphoretic contributions valid for arbitrary values of and is obtained from a balance between the electrostatic and hydrodynamic forces acting on it, where is the Debye screening parameter, is the radius of the particle, and is the radius of the cavity. The effect of the charged cavity wall on the diffusiophoresis of the particle is interesting and can be significant. The contributions from the diffusioosmotic (electroosmotic and chemiosmotic) flow occurring along the cavity wall and from the wall-corrected diffusiophoretic driving force to the particle velocity are equivalently important, and this diffusioosmotic flow can reverse the direction of the particle velocity, which in general increases with an increase in and decreases with an increase in , but exceptions exist.

Within this Ph.D. thesis, the optical thickness and particle effective radius of cirrus and deep convective clouds (DCCs) are retrieved using passive remote sensing techniques. For this purpose, airborne and satellite measurements of spectral solar radiation combined with extensive radiative transfer simulations have been conducted. Data analyzed in this study were collected during the ML-CIRRUS and the ACRIDICON-CHUVA campaigns, which aimed to study natural and contrail cirrus over Europe and DCCs over the Amazon rainforest using the German High Altitude and Long Range Research Aircraft (HALO), respectively. During the campaigns, HALO was equipped with a comprehensive set of remote sensing and in situ instruments. In particular flights, closely collocated measurements with the overpasses of the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard of the Aqua satellite were carried out. A cirrus located above liquid water clouds and a DCC topped by an anvil cirrus are investigated. In general, the research framework can be divided into four parts. In the first part, the spectral upward radiances measured by the Spectral Modular Airborne Radiation Measurement System (SMART)-Albedometer aboard of HALO are compared with those measured by the MODIS. In the second part, a radiance ratio retrieval assuming a vertically homogeneous cloud is applied to obtain the cloud optical thickness and particle effective radius based on the measurements of SMART-Albedometer and MODIS. Multiple near-infrared wavelengths with different absorption characteristics are utilized in the retrieval in order to study the vertical structure of cloud particle sizes. In the third part, the retrieved cloud properties are compared with those derived from the MODIS cloud products. For the cirrus case, the retrieved values of particle effective radius are further compared to in situ data measured by the Cloud Combination Probe (CCP). To allow this comparison, a vertical weighting method is applied. Although the comparison results in a good agreement, retrievals using this conventional technique only provide information on cloud particle sizes from the upper layers, even if spectral measurements have been employed. The retrieved particle effective radius represents a vertically weighted value, where the upper cloud layers are weighted at most. In the fourth part, an extended technique based on Bayesian optimal estimation has been developed to obtain the full vertical profile of particle effective radius. For this purpose, a parameterization assuming the shape of the vertical profile with respect to a vertical coordinate within the cloud is applied. The information content of SMART-Albedometer measurements is analyzed to identify wavelengths that bring the most information pertaining to each retrieval parameter. The new retrieval technique is applied to the cirrus case to infer the profile of particle effective radius as a function of optical thickness. The comparison between the retrieved and the in situ profiles shows a good agreement with a deviation of about 5 % at the cloud top and increases to values of up to 15 % at the cloud base. The new retrieval technique has shown excellent skill in improving the study of the vertical profile of cloud microphysical properties, which can be applied in the future generation of airborne and satellite retrievals based on the measurements of passive remote sensing.:1. Introduction 2. Definitions 3. Measurements 4. Comparison of upward radiance 5. Retrieval of cloud optical thickness and particle effective radius 6. Comparison of cloud optical thickness and particle effective radius 7. Retrieval of the vertical profile of particle effective radius 8. Summary and conclusion

碩士
國立中山大學
材料與光電科學學系研究所
98
Polymer light emitting diodes (PLED) were using a heterocyclic aromatic rigid-rod polymer poly-p-phenylene-benzobisoxazole (PBO) as an opto-electronically active layer; and poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonic acid) (PEDOT:PSS) as a hole transporting layer. Aluminum (Al) and indium tin oxide (ITO) were served as device cathode and anode, respectively. [6,6]-phenyl C61-butyric acid methyl ester (PC61BM) or derivatized multi-wall carbon nano-tube (MWCNT-C18), with great electron transporting ability, was doped into PBO to enhance the performance of PLED devices as well as the thin-film electrical conductivity. The optical length was changed by using different spin coating speeds and durations. From the research, the λmax of electroluminescence (EL) was blue-shifted as PEDOT:PSS spin coating speed increased for a thinner layer. Once using a higher spin coating speed repeatedly to coat PEDOT:PSS, the λmax of electroluminescence was red-shifted. If the PEDOT:PSS film thicknesses were similar, the EL spectra were almost the same, independent of device processing scheme. The injection current and EL intensity were enhanced by doping PC61BM or MWCNT- C18. The electric conductivity parallel to film surface (σ∥) was increased as the doping concentration increased. Because of the extremely different aspect ratio, the MWCNT-C18 had a lower percolation threshold concentration. Therefore, at a low MWCNT-C18 doping concentration, the injection current and the EL intensity were enhanced compared with those of PC61BM.

>Magister Scientiae - MSc
To study nuclear reactions and nuclear structures, target materials are bombarded with high-energy particles. The target material can either be in a form of a metal film or gas. A target material designed to study certain nuclear reactions or to produce nuclei to study their structure should yield as minimum as possible of competing reactions under ion bombardment. This requires a chemically and isotopically pure target material prepared as a self supporting thin film, or as alternative, prepared on a thin career foil. Additional requirement for lifetime measurement experiments are homogeneity and precise thickness of the target material. Some of the data obtained from the stopping power experiment where targets of 114Cd were used for lifetime measurement are presented. Moreover, a nuclear target should influence the spectroscopic resolution as little as possible. Thus, film thickness must be adjusted to the respective reaction under study while observing the optimum thickness homogeneity.

Being able to extrapolate interaction values from a database of pullout resistance testing results may possibly help with narrowing down the most suitable reinforcement/fill material combinations for a Mechanically Stabilized Earth wall, thereby reducing the number of tests needed for a design and maximizing the efficiency of the system. The objectives of this thesis include the following: collect and organize a broad collection of data in a way that can assist in preliminary selection of interaction properties for uniaxial geogrids; analyze the collection of data for trends related to geogrid polymer type; analyze the collection of data for trends related to the presence of fines in the fill material; compare the collected data to previous studies on the effects of geogrid specimen length on pullout performance; and compare the collected data to previous studies on the effect of geogrid rib thickness to mean particle size ratio on normalized bearing stress and CI values. The data from 101 pullout tests are presented in tabular and graphic form so that the coefficient of interaction may be interpolated for many geogrid/fill material combinations. The effect of polymer type (PET vs HDPE) was shown to have little effect on how a geogrid performs in a fill material. In one case, the two polymer types exhibit differing trends within the same fill material. The presence of fines (>12% by weight) in the fill material results in a significant decrease in the coefficient of interaction when compared to clean granular fills. The effects of geogrid embedment length have significant effects on the results of geogrid pullout tests. Samples with shorter lengths were shown to carry a greater load per unit area than longer samples. Normalized bearing stress is shown to be heavily influenced by the geogrid transverse rib thickness to mean particle size ratio (B/D50). For a particular fill material, normalized bearing stress decreases linearly with increasing B/D50. For a particular geogrid, normalized bearing stress is shown to have a bi-linear behavior with increasing B/D50. Initially, normalized bearing stress increases with increasing B/D50. After reaching a peak, normalized bearing stress begins to decrease with increasing B/D50.
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