Bulk laser-induced breakdown and self-focusing in single samples of fused quartz and NaCl were examined using picosecond optical pulses at 1.0 ym and 0.5 ym. The results of three separate but related experiments are reported. First the nonlinear index of refraction, n2, of each of the test materials is measured near the respective damage thresholds of the samples. The values of 1*2 were determined by detecting beam distortions in the far field, transmitted laser beam profile caused by the irradiance dependent index of refraction. The experimental traces were compared to theoretical beam profiles generated by a nonlinear propagation code and n2 was extracted from the resulting fits.

3D printable materials for RF devices need improvement in order to satisfy the demand for higher frequency and lower loss performance. Characterization of materials that have shown improvements of conductor conductivity have been performed. By using a laser machining technique the loss of a 3D printed 2.45 GHz microstrip Square Open Loop Resonator (SOLR) bandpass filter has been shown to improve by 2.1dB, along with an increase in bandwidth from 10% to 12.7% when compared to a SOLR filter that has not been laser machined. Both laser machined and microwaved silver inks have been mapped for conductivity using a Near Field Microwave Microscope (NFMM) and have shown improvement of conductivity compared to inks that have been cured using standard methods.

Abstract The reduction of product development cycle time is a major concern in industries to remain competitive in the marketplace. Among various manufacturing technologies, 3D printing technology or also known as additive manufacturing (AM), has shown excellent potential to reduce both the cycle time and cost of the product due to its lower consumption of energy and material usage compared to conventional manufacturing. Fused deposition modeling (FDM) is one of the most popular additive manufacturing technologies for various engineering applications which has the ability to build functional parts having complex geometrical shapes in reasonable build time and can use less expensive equipment and cheaper material. However, the quality of parts produced by FDM has some challenges such as poor surface quality.   The focus of this study is improving the surface quality produced by Fused Deposition Modeling. The investigations include 3D printing study samples with optimum parameter settings and post-processing the sample’s surfaces by laser ablation. Taguchi’s design of the experiment is employed to identify the optimum settings of laser ablation the FDM surfaces. Laser power, laser speed and pulse per inch (PPI) are the laser settings considered in the study. Characterization of the samples are done using Dino-lite USB camera images and GFM Mikro-CAD fringe projection microscope is used to measure the surface roughness of the samples. Areal surface parameters are used to characterize and compare the surfaces of as printed and laser ablated. It is observed that the effect of laser ablation varies with respect to surfaces printed at different angles and laser-ablated with different settings. The surface roughness of laser-ablated surfaces is found to be lower than as-printed FDM surfaces.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第22272号 / 理博第4586号 / 新制||理||1658(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)教授 大須賀 篤弘, 教授 依光 英樹, 教授 時任 宣博 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

京都大学 / 新制・課程博士 / 博士(情報学) / 甲第23323号 / 情博第759号 / 新制||情||129(附属図書館) / 京都大学大学院情報学研究科数理工学専攻 / (主査)教授 中村 佳正, 教授 矢ヶ崎 一幸, 准教授 辻本 諭 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM

The topic of diploma thesis are surface heat treatments after 3D print by method Fused Deposition Modeling. In the introduction is located recherche of the given issue. Further, we describe the construction and process of the 3D printer construction, on which will be printed samples for experiments in the next part of the thesis. The aim is to determine the behavior and changes of surface structures of heat-affected samples from different materials. Furthermore, the suitability of the used methods and the possibility of their use in practice.

The diploma thesis deals with the production process of optical part of headlamp module produced by additive technology. The thesis contains the characteristics of headlamp, current manufacturing technology and description of additive manufacturng methods. The practical part is focused on the production of a reflector using 3D printing. The conclusion of the thesis is dedicated to the measuring of light output and its evaluation.

Traditionally, the mechanical testing of ankle-foot orthoses (AFOs) has been performed with simple limb surrogates, typically with a single axis ankle joint and rigid foot and shank components. Since many current AFO designs allow 3D motion, a surrogate lower limb (SLL) that provides anatomically similar motion in all planes is needed to enable realistic load testing and cyclic testing in a controlled manner. The aim of this thesis was to design, fabricate and test a novel SLL that provides anatomically realistic 3D foot motion, based on a consensus of the passive lower limb range of motion (RoM) found in the literature. The SLL design was inspired by the Rizzoli model, sectioning the lower limb into five segments (shank, hindfoot, midfoot, forefoot, toes). Ball and socket joints were used for the shank-hindfoot, hindfoot-midfoot, and midfoot-forefoot. Forefoot-toes used a hinge-type joint. 3D printed flexible thermoplastic polyurethane (TPU) snap-fit connectors connected the 3D printed nylon foot blocks. A threaded ball stud connected the shank shaft and hindfoot. This shank shaft was surrounded by a 3D printed polylactic acid (PLA) shank cover. The foot was cast in silicone rubber to emulate soft tissue, with a PLA custom mould based on a Össur prosthetic foot cover model. The SLL was successfully designed for easy fabrication using readily available techniques, materials, and components. Only the metal shaft required additional machining. 3D printed components used an affordable 3D printer (Artillery Sidewinder X1), and readily available nylon, PLA, and TPU. Using motion capture testing, SLL foot rotation angles were found to be within standard deviation of mean foot passive rotation angle ranges found in the literature, showing that most joints were within 5° of target maximum rotation angles. With load testing, the SLL was shown to survive static loads representing 1.5 times body weight for a 100 kg individuals and cyclic loads representing normal gait loading for 500,000 cycles.

Hedgehog (Hh) est un morphogène secrété qui contrôle la croissance et la différentiation cellulaire chez les métazoaires. La dérégulation de son activité entraine des maladies développementales et de nombreux cancers chez l’adulte. Chez la drosophile, la transduction du signal Hh est initiée par la fixation de Hh sur son récepteur Patched (Ptc), conduisant à la stabilisation de la protéine membranaire Smoothened (Smo) et à l’activation du complexe de transduction composé de 5 protéines : les kinases Fused (Fu), PKA, GprK2, la kinésine Costal 2 (Cos2), et le facteur de transcription Cubitus Interruptus (Ci). Ma thèse a porté sur l’étude de la régulation et des interactions moléculaires entre les composants du complexe de transduction. Par des approches complémentaires, j’ai montré qu’en absence d’Hh, les protéines PKA et Fu interagissent du côté C-terminal de Ci, alors que la présence d’Hh induit leur relocalisation vers le domaine N-terminal de Ci. J’ai pu prouver que l’élément déclencheur de ce remaniement protéique est Smo. En présence d’Hh, Smo s’incorpore dans le complexe de transduction, conduisant à l’activation et au déplacement de Fu vers la région N-terminale de Ci. Ce remaniement entraine la phosphorylation et l’activation de Ci. Ma thèse révèle l’importance des changements de conformation au sein du complexe de transduction de la voie Hh. Le mécanisme de transduction étant conservé entre invertébrés et invertébrés, mon doctorat apporte des éléments de recherche pour mieux comprendre le fonctionnement normal et pathologique des cellules. / Hedgehog (Hh) is a secreted morphogen that controls growth and differentiation in both vertebrates and invertebrates. The dysregulation of its activity leads to severe developmental defects, and the onset of cancer in adults. In Drosophila, the Hh signal transduction is initiated by the binding of Hh to its receptor Patched (Ptc). This induces the stabilization of the transmembrane protein Smoothened (Smo) and the subsenquent activation of a transduction complex consisting of 5 proteins: the kinases Fused (Fu), PKA and Gprk2, the kinesin Costal2 (Cos2), and the transcription factor of the pathway Cubitus Interruptus (Ci). The aim of my thesis was to study the regulation and molecular interactions between the different components of the transduction complex. Thanks to complementary techniques, I have shown that in absence of Hh the proteins Fu and PKA interact in C-terminal part of Ci, whereas on the presence of Hh induces their relocalization toward the N-terminal domain of Ci. I have proved that the trigger element of this moving is Smo. In presence of Hh, Smo goes into transduction complex, allowing the activation and the moving of Fu toward N-terminal domain of Ci. This relocalization is responsible of Ci phosphorylation and activation. My thesis reveals the importance of conformational changes inside the transduction complex of Hh pathway. As the mechanism of transduction is conserved between species, my PhD provides research elements in order to better understand the normal and abnormal functioning of cells.

<div>From its advent in the 1980s until the 2000s, many of the advances in additive manufacturing (AM) technology were primarily focused on the development of various 3D printing techniques. During the 2000s, AM came to a juncture where these processes were well developed and could be used effectively for rapid prototyping purposes; however, the ability to produce functional components that could reliably perform in a given system had not been fully achieved. The primary focus of AM research since this juncture has been to transition AM from a rapid prototyping technique to a legitimate means of mass manufacturing end-use products. In order to make this happen, two significant areas of research needed to be advanced. The first area focused on advancing the limited selection and functionality of the materials being used for AM. The second area focused on the characterization of the end-use products comprised of these new materials.</div><div><br></div><div>The primary goals of the work described in this document are to substantially further the field of the additive manufacturing by developing new functional materials and subsequently characterizing the resultant printed components. The primary focus of the first two chapters (Chapters 2 and 3) is to further characterize an energetic material system comprising of aluminum (Al) particles embedded in a polyvinylidene fluoride (PVDF) binder, which has been shown to be compatible with AM. This material system has the ability to be implemented as a lightweight multifunctional energetic structural material (MESM); however, significant characterization of its structural energetic properties is needed to ensure reliable MESM performance. First, variations of a previously demonstrated Al/PVDF filament were investigated in order to determine the effect of material constituents on the structural energetic properties of the material. Seven different Al/PVDF formulations, with various particle loadings and particle sizes, were considered. The modulus of elasticity and ultimate strength for the seven formulations were obtained via quasi-static tensile testing of 3D printed dogbones. The energetic performance was quantified via burning rate measurements and differential scanning calorimetry (DSC) of 3D printed samples. Next, variations in the AM process were made and the effect of print direction on the same properties was determined. Once viable MESM performance was quantified, representative structural elements were printed in order to demonstrate the ability to create structural energetic elements. During quasi-static tensile testing, it was observed that aligning the load direction perpendicular to the print direction of the component resulted in inferior mechanical properties. This reduction in mechanical properties can be attributed to the lack of continuity at material interfaces, a well studied phenomena in AM.</div><div><br></div><div>This phenomena is the primary focus of the next two chapters (Chapters 4 and 5), which investigate the polymer healing process as it pertains to fusion-based material extrusion additive manufacturing, also known as fused filament fabrication (FFF). In the context of the FFF process, the extent of the polymer healing, or lack thereof, at the layer interface is known to be thermally driven. Chapter 4 quantifies the relationship between the reduction in mechanical properties and the temperature of the previously deposited layer at the time the subsequent layer is deposited. This relationship gives insight into which parameters should be closely monitored during the FFF process. The following chapter investigates incorporating plasma surface treatment as a means to improve the reduced mechanical properties seen in Chapter 3 and 4. As plasma surface modification can affect various stages of the polymer healing process, a variety of experiments were completed to determine which mechanisms of the plasma treatment were significantly affecting the mechanical properties of the FFF components. The thermal history was analyzed and it was hypothesized that enhanced diffusion at the layer interface was not a significant contributor to, but a rather a detractor from, the improved mechanical properties in this system. A variety of tests investigating how the plasma treatment was affecting the wettability of the surface were performed and all of the tests indicated that the wettability was increased during treatment and was likely the driving mechanism causing the improvement seen in the mechanical properties. These tests give some initial insight into how to successfully pair plasma treatment capabilities with FFF systems and give insights into how that plasma treatment can affect the polymer healing process in FFF applications.</div>