Master of Science / Department of Mechanical and Nuclear Engineering / B. Terry Beck / The objective of this project was to first evaluate the feasibility of developing a viscous damping device that used a Non-Newtonian Shear Thickening Fluid (STF) and incorporating it as a door latch into an existing commercial dryer unit. The device would keep the door closed during sudden large magnitude impact loads while still allowing the door to open normally when force is applied gradually at the door handle. The first phase of the project involved performing background research on the subject and performing preliminary analysis in order to determine if the concept was feasible enough to be worth constructing a physical prototype. This preliminary analysis consisted of a literature review of existing damping mechanisms and shear thickening fluids, rheometer testing of shear thickening suspensions to obtain viscosity data, and performing numerical simulations to determine if a damper that fit the size requirements could produce enough resistance force. The focus for the second phase of the project was to demonstrate a proof of concept in the form of a working model prototype. This prototype did not need be of identical shape and proportions as the finalized design, but would be developed to facilitate experimental testing and evaluation of performance under the desired operating conditions. It was also necessary to design and construct the test setup for the dynamic testing of the dryer door opening so that the opening displacement as well as the force applied to the door could be recorded as a function of time. The final phase of the project consisted of improving upon the original prototype in order to prove the validity of a viscous latch beyond the proof of concept phase in a form closer to what is desired for the commercial product. This required reducing the physical size of the new prototype latch so as to fit within the space available in a particular dryer, incorporate a one-way ratcheting device into the latch to allow unrestricted closing of the door, and increase the operational temperature range of the damper.

京都大学 / 0048 / 新制・論文博士 / 博士(理学) / 乙第13300号 / 論理博第1563号 / 新制||理||1653(附属図書館) / (主査)准教授 王 功輝, 教授 釜井 俊孝, 教授 福田 洋一 / 学位規則第4条第2項該当 / Doctor of Science / Kyoto University / DGAM

L'élongation cellulaire de cellules cultivant bout comme hyphae fongueux, inculquez hairs, des tubes de pollen et des neurones, est limité au bout de la cellule, qui permet à ces cellules d'envahir l'encerclement substrate et atteindre une cible. Les cellules cultivant bout d'équipement sont entourées par le mur polysaccharide rigide qui régule la croissance et l'élongation de ces cellules, un mécanisme qui est radicalement différent des cellules non-walled. La compréhension du règlement du mur de cellule les propriétés mécaniques dans le contrôle de la croissance et du fonctionnement cellulaire du tube de pollen, une cellule rapidement grandissante d'équipement, est le but de ce projet. Le tube de pollen porte des spermatozoïdes du grain de pollen à l'ovule pour la fertilisation et sur sa voie du stigmate vers l'ovaire le tube de pollen envahit physiquement le stylar le tissu émettant de la fleur. Pour atteindre sa cible il doit aussi changer sa direction de croissance les temps multiples. Pour évaluer la conduite de tubes de pollen grandissants, un dans le système expérimental vitro basé sur la technologie de laboratoire-sur-fragment (LOC) et MEMS (les systèmes micro-électromécaniques) ont été conçus. En utilisant ces artifices nous avons mesuré une variété de propriétés physiques caractérisant le tube de pollen de Camélia, comme la croissance la croissance accélérée, envahissante et dilatant la force. Dans une des organisations expérimentales les tubes ont été exposés aux ouvertures en forme de fente faites de l'élastique PDMS (polydimethylsiloxane) la matière nous permettant de mesurer la force qu'un tube de pollen exerce pour dilater la croissance substrate. Cette capacité d'invasion est essentielle pour les tubes de pollen de leur permettre d'entrer dans les espaces intercellulaires étroits dans les tissus pistillar. Dans d'autres essais nous avons utilisé l'organisation microfluidic pour évaluer si les tubes de pollen peuvent s'allonger dans l'air et s'ils ont une mémoire directionnelle. Une des applications auxquelles le laboratoire s'intéresse est l'enquête de processus intracellulaires comme le mouvement d'organelles fluorescemment étiqueté ou les macromolécules pendant que les tubes de pollen grandissent dans les artifices LOC. Pour prouver que les artifices sont compatibles avec la microscopie optique à haute résolution et la microscopie de fluorescence, j'ai utilisé le colorant de styryl FM1-43 pour étiqueter le système endomembrane de tubes de pollen de cognassier du Japon de Camélia. L'observation du cône de vésicule, une agrégation d'endocytic et les vésicules exocytic dans le cytoplasme apical du bout de tube de pollen, n'a pas posé de problèmes des tubes de pollen trouvés dans le LOC. Pourtant, le colorant particulier en question a adhéré au sidewalls du LOC microfluidic le réseau, en faisant l'observation de tubes de pollen près du difficile sidewalls à cause du signal extrêmement fluorescent du mur. Cette propriété du colorant pourrait être utile de refléter la géométrie de réseau en faisant marcher dans le mode de fluorescence. / Cellular elongation of tip-growing cells such as fungal hyphae, root hairs, pollen tubes and neurons, is limited to the tip of the cell, which enables these cells to invade the surrounding substrate and to reach a target. Tip-growing plant cells are surrounded by the stiff polysaccharidic wall that regulates the growth and elongation of these cells, a mechanism that is very different from non-walled cells. Understanding the regulation of the cell wall mechanical properties in controlling growth and cellular functioning of the pollen tube, a rapidly growing plant cell, is the goal of this project. The pollen tube carries sperm cells from the pollen grain to the ovule for fertilization and on its way from the stigma towards ovary the pollen tube physically invades the stylar transmitting tissue of the flower. To reach its target it also has to change its growth direction multiple times. To assess the behavior of growing pollen tubes, an in vitro experimental system based on lab-on-chip (LOC) technology and MEMS (microelectro-mechanical systems) was designed. Using these devices we measured a variety of physical properties characterizing the pollen tube of Camellia, such as growth velocity, invasive growth and dilating force. In one of the experimental set-ups the tubes were exposed to slit-shaped openings made of elastic PDMS (polydimethylsiloxane) material allowing us to measure the force a pollen tube exerts to dilate the growth substrate. This invasion capacity is crucial for pollen tubes to allow them to enter narrow intercellular spaces within the pistillar tissues. In other assays we used the microfluidic set-up to test whether pollen tubes can elongate in air and whether they have a directional memory. One of the applications that the lab is interested in is the investigation of intracellular processes such as the motion of fluorescently labelled organelles or macromolecules while the pollen tubes grow within the LOC devices. To prove that the devices are compatible with high-resolution optical microscopy and fluorescence microscopy, I used the styryl dye FM1-43 to label the endomembrane system of Camellia japonica pollen tubes. Observation of the vesicle cone, an aggregation of endocytic and exocytic vesicles in the apical cytoplasm of the pollen tube tip, did not pose any problems in pollen tubes located within the LOC. However, the particular dye in question adhered to the sidewalls of the LOC microfluidic network, making viewing of pollen tubes close to the sidewalls difficult because of the highly fluorescent signal of the wall. This property of the dye might be useful to image the network geometry when operating in fluorescence mode.

Projektet behandlar utvecklingen av ett handledsskydd anpassat för snowboardåkare. Den primäramålsättningen är att med hjälp av optimerad design för komfort och användarvänlighet kunnaerbjuda ett högkvalitativt och funktionellt skydd. Det senare uppnås med hjälp av material som medhänsyn till skadebilden hos utövarna här anses vara den bästa lösningen. Val av material gjordes efteren ingående litteraturstudie över handledsskyddets funktion och mekanismerna bakomhandledsskador. Studien, i kombination med en rad andra metoder för informationsinhämtning, lågäven till grund för designprocessen och den slutgiltiga produkten.Lösningar på befintliga problem hos existerande handledsskydd har applicerats på slutprodukten.Användarvänlighet och passform har tillgodosetts genom att frångå det traditionella systemet medkardborrelås, till produktanpassning av ett etablerat snörsystem. En ökad bekvämlighet tillgodosesgenom hela skyddets form, men även med utvalda material, då dessa tillåter luftgenomströmninggenom skyddet.Inom ramen för projektet besvaras också frågeställningar rörande varför så få utövare använderhandledsskydd, och vad som kan göras för att locka till användning. Handledsskydd är idagimpopulära hos utövarna, trots att frakturer på handled är den vanligaste skadan förknippad medsnowboard. Genom utveckling av bättre skydd kan skadestatistiken kraftigt förbättras. / The project aims to develop customized wrist guards for snowboarders. By using optimized design for comfort and ease of use, the primary aim is to offer the customer a functional and high-quality protection. This is achieved by using materials that, considering the injury status of the practitioners, herein are considered to best meet the demands of such a protection. The choice of materials was made after a comprehensive literature-based study on wrist guard function and mechanisms responsible for wrist injuries. This study, along with other collected data, has formed the basis for the design process and the final product. Solutions to current problems with existing wrist guards have been applied to the final product. Requirements on ease of use and accuracy of fit have been met by abandoning the traditional closure-system of Velcro, in favor for an established lacing system that has been adapted to the current product. The entire shape of the wrist guard, combined with the selected materials breathable qualities, offers the user an increased comfort. The complementary aim of the project is to understand why so few practitioners wear wrist guards, and bring forth solutions that attracts to the usage of such. Wrist guards are currently unpopular amongst snowboarders, despite wrist fracture being the most common injury associated with the sport. Through the development of better wrist guards the injury statistics can be greatly improved.