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京都大学 / 新制・課程博士 / 博士(工学) / 甲第23895号 / 工博第4982号 / 新制||工||1778(附属図書館) / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 奥田 浩司, 教授 安田 秀幸, 教授 辻 伸泰 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Aim: The aim is to evaluate the fracture strength and fracture type of long-term water-stored monolithic 3-unit multilayered zirconia fixed dental prostheses (FDPs) depending on connector dimension and placement in disc. Material and method: Thirty-two 3-unit FDPs (212223) of KATANATM Zirconia Yttria Multilayered (YML) were divided into four groups (n=8/group). The EB-groups were placed in Enamel layer/Body layer 1 in the disc, with connector dimensions of 12 mm2 (EB12), or 7 mm2 (EB7). The BB-groups were placed in Body layer 2/Body layer 3, with connector dimensions 12 mm2 or 7 mm2 (BB12 and BB7). All FDPs were long-term water-stored (37° C, one year). They were cemented on die models, cyclic mechanical preloaded (10,000 cycles), followed by fracture strength test. The results were analyzed with one-way ANOVA, Tukey's test, significance level α = 0.05. Fracture type analysis was performed visually and presented descriptively. Result: Group BB12 showed significantly higher strength (2660 N) compared to EB7 with the lowest mean value (1044 N) (p < 0.05). There was no significant difference between the remaining groups. Conclusion: Design and placement of monolithic 3-unit FDPs in multilayered zirconia affects the fracture strength and fracture type.With increased connector dimension the location can be in the upper layer of the disc, and with reduced connector dimension, the location can be in the lower layer. The fractures occur in the connectors of the pontic. With an increased connector dimension and the FDP located in the lower layer, a total fracture will occur / Syfte: Syftet med föreliggande studie är att utvärdera brotthållfastheten och frakturtyp på långtidsvattenförvarade monolitiska 3-leds-broar som framställts i flerskiktad zirkonia med olika konnektordimensioner och placering i disk. Material och metod: Trettiotvå 3-leds-broar med två preparerade tänder, 212223 delades in i fyragrupper (n=8/grupp) beroende på dimensionering av konnektorn och placering i KATANATM Zirconia Yttria Multilayered (YML)-disk. Grupperna EB var placerade i Enamel layer/Body layer 1 i disken,med konnektordimension på antingen 12 mm2 för grupp EB12, eller 7 mm2 för grupp EB7. Grupperna BB var placerade i Body layer 2/Body layer 3 i disken, med konnektordimensionerna 12 mm2 för grupp BB12 respektive 7 mm2 förBB7. Samtliga broar förvarades i vatten, 37° C under ett år. Broarnacementerades på stansmodeller. Efter 24 h genomfördes cyklisk mekanisk förbelastning, 10 000 cykler, följt av ett brotthållfasthetstest. Resultaten analyserades med one-way ANOVA, Tukey’s test,signifikansnivå α = 0,05. Frakturtypsanalys genomfördes visuellt och resultaten presenterades deskriptivt. Resultat: Grupp BB12 hade signifikant högre brotthållfasthet (2660 N) jämfört med EB7 som hade lägst medelvärde (1044 N) (p ≤ 0,05). Mellan övriga grupper fanns det ingen signifikant skillnad.Majoriteten av frakturerna skedde i det hängande ledet. Även totalfrakturer förekom. Slutsats: Utformning och placering av monolitiska 3-leds-broar i ett flerskiktat zirkoniamaterial påverkar brotthållfastheten och frakturtyp. Vid ökad konnektordimension kan placeringen vara i det övre skiktet i disken. Vid minskad konnektordimension kan placering vara i nedre skikt. Frakturerna sker vid det hängande ledet, och vid ökad konnektordimensionering och placering i nedre skikt sker totalfraktur

Wireless systems are rapidly developing to provide high speed voice, text and multimedia messaging services which were traditionally offered by wire line networks. To support these services, channels with large capacities are required. Information theoretic investigations have shown that Multiple Input Multiple Output (MIMO) channels can achieve very high capacities. Space-Time Block Coding (STBC) and Bell Labs Layered Space-Time Architecture (BLAST) are two potential schemes which utilize the diversity offered by MIMO channels to provide reliable high date rate wireless communication. This work studies the sensitivity of these two schemes to spatial correlation in MIMO channels. The first part of the thesis studies the effect of spatial correlation on the performance of STBC by using Geometrically Based Single Bounce MIMO (GBSB-MIMO) channel models. Performance is analyzed for two scenarios: one without scatterers in the vicinity of the transmitter and other with scatterers. In the second part of the thesis, the sensitivity of BLAST to spatial correlation is analyzed. Later, schemes which use the principles of Multilayered Space-Time Coded Modulation to combine the benefits of BLAST and STBC are introduced and their performance is investigated in correlated and uncorrelated Rayleigh fading. Results indicate that schemes using orthogonal design space-time block codes are reasonably robust to spatial correlation while schemes like BLAST are very sensitive as they depend on array processing to separate signals from various transmit antennas. / Master of Science

Calcific aortic valve disease (CAVD) is associated with significant cardiovascular morbidity. While late-stage valve disease is well-described, there remains an unmet scientific need to elucidate early pathobiological processes. In CAVD, pathological differentiation of valvular interstitial cells (VICs) and lesion formation occur focally in the fibrosa layer. This VIC pathological differentiation has been shown to be influenced by matrix stiffness in vitro. However, little is known about the focal layer specific mechanical properties of the aortic valve in health and disease and how these changes in matrix moduli may influence VIC pathological differentiation in vivo. In this thesis, micropipette aspiration (MA) was shown to be capable of measuring the mechanical properties of a single layer in multilayered biomaterial or tissue such as the aortic valve, if the pipette inner diameter was less than the top layer thickness. With MA, the fibrosa of normal porcine aortic valves was significantly stiffer than the ventricularis; stiffer locations found only within the fibrosa were comparable to stiffnesses shown in vitro to be permissive to VIC pathological differentiation. Early CAVD was induced in a porcine model, which developed human-like early CAVD lesion onlays. Extracellular matrix remodeling occurred in the absence of lipid deposition, macrophages, osteoblasts, or myofibroblasts, but with significant proteoglycan-rich onlays and chondrogenic cell presence. These early onlays were softer than the collagen-rich normal fibrosa, and their proteoglycan content was positively correlated with Sox9 chondrogenic expression, suggesting that soft proteoglycan-rich matrix may be permissive to chondrogenic VIC differentiation. The findings from this thesis shed new light on early disease pathogenesis and improve the fundamental understanding of aortic valve mechanics in health and disease.

Ce travail de thèse concerne l’étude de différents revêtements type « Diamond-Like Carbon » élaborés par un procédé CVD assisté par un plasma basse fréquence (40 kHz). Deux revêtements de référence sont d’abord étudiés : des couches de carbone amorphe hydrogéné (a-C:H) et des couches de carbure de silicium amorphe hydrogéné (a-SiC:H). L’évolution de leurs propriétés mécaniques (dureté, module d’Young) et tribologiques (frottement, usure) est décrite en fonction des paramètres du procédé et corrélée à leur microstructure. Les résultats obtenus pour ces deux couches de référence sont ensuite exploités pour proposer deux systèmes complémentaires : des revêtements a-C:H dopées et des systèmes multicouche a-C:H/a-SiC:H. Ces deux solutions présentent des contraintes résiduelles réduites par rapport à un revêtement a-C:H monocouche ce qui permet d’envisager une augmentation importante des épaisseurs de dépôt tout en conservant des propriétés mécaniques et tribologiques intéressantes. Enfin, en vue d’une application industrielle de ces revêtements sur des pièces de moteur par exemple, l’optimisation de leur adhérence par insertion de sous-couches adaptées ainsi que de leurs performances tribologiques en conditions lubrifiées par l’intermédiaire de texturation de surface est alors envisagée / Hydrogenated amorphous carbon films (a-C:H) and hydrogenated silicon carbide films (a-SiC:H) are deposited by low frequency (40 kHz) plasma enhanced chemical vapour deposition (LF PECVD). Structural, mechanical and tribological properties of those single layers have been first studied in relation with process parameters. Then those results have been used to study two other systems. The first one corresponds to silicon doped a-C:H thin films and the second one to multilayered coatings consisting in a stack of a-C:H and a-SiC:H layers. Those coatings offer potential advantages such as lower residual stress level comparing to that of a-C:H stress level which gives the opportunity to deposit thicker films, and also attractive mechanical and tribological properties. Moreover, in case of applications like car engine parts for example, adhesion and tribological properties under lubrication have to be improved. Solutions as incorporating underlayer or texturing surface are thus also investigated in this study

Small and medium-sized enterprises (SMEs) account for approximately 50% of the world's gross domestic product. However, these economic agents suffer from inadequate access to liquid funds to finance their operations. The liquidity gap has led to early bankruptcy and liquidation, stagnant growth and development, and fewer employment opportunities. The problem under study was the effect of funding limitations on SMEs' business operations and growth. The purpose was to examine the impact of multilayered capital systems as alternative funding for SME growth. This study was informed by Gilbrat's law and the theory of financial exclusion. The research questions addressed the use of a multilayered capital market as a substitute for the conventional methods of funding for SMEs. A survey instrument was used to collect data using a stratified random sample of 54 small-scale business owners and finance professionals. These participants were identified from U.S. Census Bureau data between 2009 and 2014 across the information technology, service, and manufacturing sectors. Multiple regressions and correlation analyses were used to analyze the data. The results showed that age, credit score, average turnover, and total assets have significant impacts on obtaining funding, especially total assets. Moreover, results showed that growth rates correlated with funding from multilayered capital systems. This study contributes positively to social change by highlighting alternative means of funding SMEs, leading to reduced dependency on government, less crime through gainful employment, and improved corporate social responsibility due to better interactions among community members

<p>The work presented in this thesis describes the use of polystyrene nanoparticles as model surfaces for bioanalytical work. Nanoparticles constitute convenient platforms for the attachment of bioactive agents, and receptor coated particles offer high local concentration of binding sites for specific ligands with minimal steric hindrance. However, it is not only the amount of bound protein that matters, the proteins must also be immobilized at the surface in such ways that they fully retain their activity, while at the same time protecting the surface from unspecific uptake of undesired components. The present work relates to the controlled immobilization of multiple types of active biomolecules onto nanoparticle surfaces to make them multifunctional. The surface expansion offered by the nanoparticles, in combination with the closeness between the reactants co-immobilized on the same particle, enables coupled reactions to be carried at a higher rate than otherwise possible. Thus, particle-decorated surfaces of this kind are highly suitable for miniaturized bioanalytical systems. Sensitive microarray systems are under development, including lectin-coated nanoparticles for glycoprotein mapping and a diagnostic device for Point-of-Care testing with a nanoparticle-based detection system.</p><p>The full evaluation of protein attachment to nanoparticles requires precise analytical techniques for particle characterization, both in bare and coated form. The mass-sensitive SdFFF technique occupies a prominent position for particle characterization, as it offers both accurate determination of particle size and a quantification of adsorbed layers on small particles, whether of synthetic or biopolymeric nature. Here, this analytical technique is developed to precisely characterize nanoparticles that are sequentially coated with different layers, each rendering the particles a specific functionality. The thesis demonstrates how precise mass uptakes can be determined for each specific layer, and how control over the exact surface composition of the modified particles can be established for optimization of biological activity.</p>

The determination of the atmospheric aerosol size distribution is an inverse illposed problem. The shape and the material composition of the air-carried particles are two substantial model parameters. Present evaluation algorithms only used an approximation with spherical homogeneous particles. In this paper we propose a new numerically efficient recursive algorithm for inhomogeneous multilayered coated and absorbing particles. Numerical results of real existing particles show that the influence of the two parameters on the model is very important and therefore cannot be ignored.

The work presented in this thesis describes the use of polystyrene nanoparticles as model surfaces for bioanalytical work. Nanoparticles constitute convenient platforms for the attachment of bioactive agents, and receptor coated particles offer high local concentration of binding sites for specific ligands with minimal steric hindrance. However, it is not only the amount of bound protein that matters, the proteins must also be immobilized at the surface in such ways that they fully retain their activity, while at the same time protecting the surface from unspecific uptake of undesired components. The present work relates to the controlled immobilization of multiple types of active biomolecules onto nanoparticle surfaces to make them multifunctional. The surface expansion offered by the nanoparticles, in combination with the closeness between the reactants co-immobilized on the same particle, enables coupled reactions to be carried at a higher rate than otherwise possible. Thus, particle-decorated surfaces of this kind are highly suitable for miniaturized bioanalytical systems. Sensitive microarray systems are under development, including lectin-coated nanoparticles for glycoprotein mapping and a diagnostic device for Point-of-Care testing with a nanoparticle-based detection system. The full evaluation of protein attachment to nanoparticles requires precise analytical techniques for particle characterization, both in bare and coated form. The mass-sensitive SdFFF technique occupies a prominent position for particle characterization, as it offers both accurate determination of particle size and a quantification of adsorbed layers on small particles, whether of synthetic or biopolymeric nature. Here, this analytical technique is developed to precisely characterize nanoparticles that are sequentially coated with different layers, each rendering the particles a specific functionality. The thesis demonstrates how precise mass uptakes can be determined for each specific layer, and how control over the exact surface composition of the modified particles can be established for optimization of biological activity.