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A thermo-mechanical finite element model is developed to determine the temperature history and residual stresses in a Cu-H13 thin-walled plate deposited by the Laser Engineered Net Shaping (LENSTM) process. The same model is also applied to a H13-H13 sample to compare the results. The input laser power is adjusted to maintain a steady molten pool size and depth. For a constant scanning speed the laser power decreases with the addition of more layers, and with the increase of scanning speed the laser power needs to be increased. The Z-component of residual stresses is greater than the other components, and is compressive near the center of the wall and tensile at the free edges. The residual stress levels near the free edges are higher in the H13-H13 sample than in the Cu-H13 sample. In these regions, the use of unidirectional scanning results in a higher stress accumulation than the alternating scanning.

Thesis advisor: Joshua E. Greene / We develop and implement obstructions to realizing a 3-manifold all of whose prime summands are lens spaces as Dehn surgery on a knot K in the Poincaré homology sphere, and in the process, we determine the knot Floer homology groups of a knot with such a surgery. We show that such a surgery never results in a 3-manifold with more than three non-trivial summands, and that if the result of surgery has exactly three non-trivial summands, then K is isotopic to a regular Seifert fiber. We furthermore identify the only two knots with half-integer lens space surgeries, and thus complete the classification of knots in the Poincaré homology sphere with non-integer lens space surgeries. We lastly show that a lens space L(p, q) that is realized as integer surgery on a knot K is realized as integer surgery on a Tange knot when p ≥ 2g(K). In order to do so, we build on Greene’s work on changemaker lattices and develop the theory of E8-changemaker lattices. / Thesis (PhD) — Boston College, 2023. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Mathematics.

水晶体のようにレンズを動かすことなく，その焦点距離の制御を行うため、本論文では複屈折性をもつ液晶材料を利用した小型かつ薄型で耐環境性の高い可変焦点レンズ（液晶レンズ）の開発を目指している．特に、従来のように液晶の分子配向制御に電界を用いず、超音波振動により分子配向を静的に制御する手法とそのメカニズムの解明を目的とする。 / Variable-focus ultrasound liqui dcrystal lenses combining ultrasonic waves and liquid crystal materials were developed and investigated, focusing on the multifunctional properties that were not possible with conventional optical lenses. In particular, control of the effective lens aperture, control of the focal point in the radial direction for image stabilizationt, and expansion of the focal length variation range, which had been considered a problem from a practical standpoint, were investigated. / 博士(工学) / Doctor of Philosophy in Engineering / 同志社大学 / Doshisha University

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Wavefront sensing is a fundamental problem in applied optics. Wavefront sensors that work in a deterministic manner are of particular interest. Initialized with a unified theory for classical wavefront sensors, this dissertation discusses relevant properties of wavefront sensor designs. Based on which, a new wavefront sensor, termed Coded Wavefront Sensor, is proposed to leverage the advantages of the analysis, especially the lateral wavefront resolution. A prototype was built to demonstrate this new wavefront sensor. Given that, two specific applications are demonstrated: megapixel adaptive optics and simultaneous intensity and phase imaging. Combined with a spatial light modulator, a hardware deconvolution approach is demonstrated for computational cameras via a high resolution adaptive optics system. By simply switching the normal image sensor with the proposed one, as well as slight change of illumination, a bright field microscope can be configured to a simultaneous intensity and phase microscope. These show the broad application range of the proposed computational wavefront sensing approach. Lastly, this dissertation proposes the idea of differentiable optics for wavefront engineering and lens metrology. By making use of automatic differentiation, a physically-correct differentiable ray tracing engine is built, with its potentials being illustrated via several challenging applications in optical design and metrology.

The development of 5G and 6G entails new demandson antennas. This includes fast and reliable connections to a largenumber of devices. A wider area of coverage, and thus moreantennas are also expected, which is problematic for the expensiveantennas used today. To meet those demands, a geodesic lensantenna has been proposed. The antenna utilises several feedingports for beam forming. It is designed to operate at a frequencyof 8 to 12 GHz and is optimised to have an even coverage in thefar-field. The design is modulated with one fold to reduce theheight of the antenna. A prototype of the antenna is 3D printedwith PLA and coated with aluminium tape. The design has asimulated realised gain of 13.5 dBi and beam width of around30°. The 3D printed antenna could not be tested due to technicalproblems with the testing facilities, but is expected to have similarresults. / Med utvecklingen av 5G och 6G kommer stora krav på antenner. Flera enheter skall kunna vara uppkopplade och samtidigt krävs högre hastigheter med stabil uppkoppling. Utöver det ställs det även krav på en bred täckning vilket innebär att fler antenner behöver kopplas upp, vilka har höga kostnader idag. För att möta dessa krav har en design för en geodetisk linsantenn lagts fram. Antennen använder flera ingångar för att skapa en riktbar stråle. Den är designad för att operera inom frekvenserna 8 till 12 GHz och är optimerad för att få en jämn täckning i fjärrfältet. Designen nyttjar en vikning för att minska antennens höjd. En prototyp av antennen tillverkas med hjälp av 3D printad plast som beläggs med aluminiumtejp. Designen har en simulerad förstärking av 13.5 dBi och en strålbredd runt 30°. Den 3D printade antennen kunde inte testas på grund av tekniska problem med testutrustningen men förväntas ha liknande resultat som den simulerade. / Kandidatexjobb i elektroteknik 2022, KTH, Stockholm

The purpose of the study was to investigate pornography use in the context of leisure boredom. The sample consisted of N = 290 married couples (N = 580 individuals) from a large Northwestern city in the United States. When controlling for demographic variables, leisure boredom accounted for 2.2% of the variance within pornography use. Results suggest leisure boredom as a significant predictor of pornography use in married adults. A quadratic effect was also found, suggesting this relationship to be curvilinear. Findings are discussed around the use of leisure theory in pornography scholarship, in this case leisure boredom. Practical applications and suggestions for future research around sex and pornography addiction and therapeutic recreation are discussed.

Silicone Hydrogel (SiHy) contact lenses are highly successful compared to previous soft lenses; they were developed to provide superior oxygen permeability. However, the hydrophobic natures of the silicone segments enhance lipid sorption which may diminish the lens surface wettability, clarity and comfort. While lens and lens care product are designed to remove lipid deposition, there is lack of experimental evidence to evaluate the actual performances with respect to lipid removal. An in vitro model using an artificial tear fluid containing radiolabeled lipids was employed in this thesis research to evaluate the efficacy of different multi-purpose lens care solutions in removing lipids from SiHy contact lenses. Additional rubbing with the lens care solution is often encouraged by professionals. Part of this research evaluated the effect of additional rubbing process on lipid removal. Overall, a multi-purpose solution (MPS) for lens care, Opti-Free PureMoist®, removed the most lipid deposition from lenses (senofilcon A, comfilcon A, and balafilcon A and one conventional hydrogel lens polymacon). The overall removal percentages were approximately 55% of DPPC and 28% of cholesterol from a conventional hydrogel. However, the MPSs did not remove lipids effectively from SiHy lenses. The highest percentages of removal were 3.08% of DPPC and 0.76% of cholesterol from SiHy lotrafilcon B lenses with Opti-Free PureMoist. The rubbing process increased the amount of removal in some MPSs, but the effects were small. The lack of removal of lipid suggests that the surfactants in the MPSs are not hydrophobic enough to remove lipids from SiHy lenses. Apparently a majority of deposited lipids absorbed into the lens matrix as rubbing did not enhance removal significantly. Future study on determining the concentration profile of lipid sorption throughout the lens thickness is encouraged. Another topic in this research thesis is the use of hydrogel lenses to deliver comfort agents or lubricating molecules from lenses. A screening study was performed in this research to select possible agents to be loaded into several SiHy macromer formulations. Experiments showed that comfort agents PNVP and Kollidon were the best candidates for such a procedure.