京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21005号 / 医博第4351号 / 新制||医||1028(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 小西 靖彦, 教授 福原 俊一, 教授 小池 薫 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DGAM

Hybrid organic-inorganic materials represent a new class of materials having scientific and technological potential. In this thesis, Polyhedral Oligomeric Silsesquioxanes (POSS) are used as an inorganic building block which has been tethered to an organic polymer. POSS are silica precusors, having a well defined silsesquioxane cental core surrounded by an organic periphery which makes them compatible with monomers and possibly polymers. The objectives of this study are to (1) study the basic structures of POSS homopolymers, (2) to incorporate POSS building blocks by a bottomup approach into polymer chains and study the resulting morphologies, and (3) to study the thin film behavior of POSS block copolymers. PMA and styryl POSS homopolymers of different peripheries were synthesized by ATRP and mass spectrometry studies were carried out by MALDI-TOF and ESI. PMA POSS chains undergo a number of fragmentations while styrly POSS chains have a relatively robust backbone. Poly(ethylene-butylene-b-MAPOSS), AB type copolymers and poly(MAPOSS-b-styrene-b-MAPOSS), ABA type copolymers were synthesized by a combination of anionic and ATRP polymerization. Spheres, inverse cylinders, lamellar and crystalline lamellar morphologies were observed for the poly(ethylene-butylene-b- MAPOSS) copolymers. In the poly(MAPOSS-b-styrene-b-MAPOSS) copolymers, cylindrical, lamellar and perforated lamellar morphologies were obtained. Beyond the interaction parameter (χ), total degree of polymerization (N) and volume fraction (f), the conformational asymmetry (ε) also plays an important role in determining the morphology of these block copolymer. Crystallization of the POSS phase and better thermal properties were observed in the both block copolymers. Thin film studies of poly(MAPOSS-b-styrene-b-MAPOSS) copolymers showed that the microdomains can be oriented either parallel or perpendicular to the substrate depending upon the film thickness, morphology and relative volume fractions of the connecting blocks. By removal of the organic phase, ordered mesoporous low dielectric constant silica films were obtained. These hybrid block copolymers are a potential candidate for nanopatterning applications.

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Steel plate shear walls (SPSWs) are popular lateral force resisting systems whose practical applications range from high seismic regions to medium and low seismic areas and wind load applications. The factors which make SPSW attractive include its energy dissipation capacity, excellent ductility, constructability, speed of construction compared to concrete shear walls, reduced architectural footprint compared to concrete shear walls, and increased inelastic deformation capacity as compared to braced frames. The principle behind current SPSW design is that the post-buckling tension field capacity of the thin web plate is proportioned to resist the full lateral load. The resulting web plate is typically quite thin, buckles at low loads, possesses low stiffness, and does not provide resistance when the lateral loads are reversed until the tension field engages in the opposite direction. To compensate for these shortcomings, moment connections are required at the beam to column connections to improve energy dissipation, increase stiffness, and provide lateral resistance during load reversal. The resulting SPSW designs with very thin web plates, moment connections, and beams and columns significantly larger than comparable braced frames, can result in inefficient structural systems. The objective of this work is to develop steel plate shear wall systems that are more economic and efficient. In order to achieve this, approaches like shear connections between beams and columns, allowing some yielding in columns and increasing plate thicknesses were attempted. But these approaches were not effective in that there was no reduction in the amount of steel required since stiffness controlled the designs. This necessitated the creation of tunable steel plate shear wall systems in which strength and stiffness could be decoupled. Preliminary analyses of seven steel plate shear wall systems which allow tunability were conducted and two configurations namely circular holes and butterfly shaped links around the perimeter, that showed promising results were chosen. The solid plate in the middle of the panel contributes significant pre-yield stiffness to the system while the geometry of the perimeter perforations controls strength and ductility. An example panel was designed using the two approaches and compared to panels designed using current SPSW design methods. The proposed configurations resulted in improved overall performance of the system in terms of energy dissipation, stable hysteresis, required less steel and no moment connections between beams and columns. This was also observed from the parametric study that was performed by varying the thickness of the web plate and the geometry of the configurations. Thus it was concluded that the two proposed configurations of cutouts were promising concepts that allow separate tuning of the system strength, stiffness and ductility and could be adopted in any seismic zone for improved seismic resistance. / Master of Science

Today’s telecommunication cabinets use Electro Magnetic Compliance (EMC) screens in order to reduce electromagnetic noise that can cause some miss functions in electronic equipment. Many radio base stations (RBSs) use a 90-degree building architecture: the flow inlet is perpendicular to the EMC screen, which creates a complex flow, with a 90-degree air turn, expansions, compressions, perforated plates and PCBs. It is of great interest to study how the EMC screen interacts with the rest of components and analyze the total pressure drop and how much the flow pattern changes due to the placement of the screen. Velocity, pressure and temperature measurements as well as flow pattern visualizations have been carried out to gain good insight into the flow and heat transfer characteristics in a subrack model of an RBS. Furthermore, these measurements have been very useful for validating detailed CFD models and evaluating several turbulence models. Nowadays, industrial competition has caused a substantial decrease in the time-to-market of products. This fact makes the use of compact models in the first stages of the design process of vital importance. Accurate and fast compact models can to a great extent decrease the time for design, and thus for production. Hence, to determine the correlations between the pressure drop and flow pattern on the PCBs as a function of the geometry and the Reynolds number, based on a detailed CFD parametric study, was one objective. Furthermore, the development of a compact model using a porous media approach (using two directional-loss coefficients) has been accomplished. Two correlations of these directional loss coefficients were found as a function of the geometry and Reynolds number. / QC 20100630

Tyrolean type water-intake structures are commonly used on mountain rivers to supply water to hydropower stations. The amount of water to be diverted from the main channel is the major concern in these kind of structures and should not be less than the design discharge. In this study a physical model of a Tyrolean type water-intake structure was built at the laboratory and the diverted flow from the main channel through the intake structure having steel racks and perforated plates of different types were measured. The experiments were conducted in two stages. In the first stage the tests were carried out with only steel racks having three different bar openings and slopes, and in the second stage, perforated screens of three different circular openings and screen slopes were used. Applying dimensional analysis to the related parameters of the system the dimensionless terms were defined for the water capture efficiency and discharge coefficient of the system, and their variations with the relevant parameters were plotted. Using these diagrams one can determine the amount of water to be diverted by a Tyrolean weir of known geometry and main channel discharge.

Made available in DSpace on 2014-06-11T19:29:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-08-19Bitstream added on 2014-06-13T19:18:07Z : No. of bitstreams: 1 gomes_dr_me_ilha.pdf: 2162915 bytes, checksum: b782fc156e610a80fbe70a64be42472e (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A cultura da acerola é de grande importância econômica para o município de Junqueirópolis, localizado na Região da Nova Alta Paulista, Estado de São Paulo. A partir do ano de 2000 vêm sendo realizados trabalhos relacionados com a irrigação da cultura, a fim de melhorar a produção e a qualidade dos frutos. Foi comparado o cultivo de sequeiro com três sistemas de irrigação (gotejamento, gotejamento em subsuperfície e mangueira perfurada a laser). Com isso, o presente trabalho avaliou os seguintes parâmetros: armazenamento de água no solo, sistema radicular, movimento de nutrientes no perfil do solo, produção da cultura, exportação de nutrientes, desempenho dos sistemas de irrigação e bulbo de umedecimento. Observou-se que a profundidade efetiva do sistema radicular da acerola encontra-se em média a 0,70 m, a água de irrigação condiciona sensíveis melhorias nas condições químicas do solo, o sistema de gotejamento promove distribuição de água a maiores profundidades, o sistema de mangueira perfurada a laser apresentou maior desgaste ao longo do tempo com CUC de 21,7%, o sistema de sequeiro foi o que apresentou maior exportação de nutrientes, bem como maior produtividade média com 48 kg.planta-1.ano-1. / The culture of Barbados cherry (Malpighia glabra Mill sp) is of great economical importance for the district of Junqueirópolis, located in the Nova Alta Paulista, region county-SP. Starting from the year of 2000 works related with the irrigation of the culture have been accomplished, in order to improve the production and the quality of the fruits. The nonirrigated cultivation was compared with three overhead irrigations (trickling, subsurface trickling and micro sprinkling and laser perforated pipes). With that, the present work evaluated the following parameters: storage of water in the soil, root system, move of nutrients in the soil profile, production of the culture, export of nutrients, discharge of system of irrigation and wetted volume. It was observed that the depth executes of the root system of the Barbados cherry meets on average to 0,70 m, the irrigation water conditions sensitive improvements in the chemical conditions of the soil, the trickling system promotes distribution of water to largest depths, the micro sprinkling and laser perforated pipes presented larger wear and tear along the time with CUC of 21,7%, the non-irrigated system was what presented larger export of nutrients, as well as larger medium productivity with 48 kg per plant per year.

abstract: High Impedance Surfaces (HISs), which have been investigated extensively, have proven to be very efficient ground planes for low profile antenna applications due to their unique reflection phase characteristics. Another emerging research field among the microwave and antenna technologies is the design of flexible antennas and microwave circuits to be utilized in conformal applications. The combination of those two research topics gives birth to a third one, namely the design of Conformal or Flexible HISs (FHISs), which is the main subject of this dissertation. The problems associated with the FHISs are twofold: characterization and physical realization. The characterization involves the analysis of scattering properties of FHISs in the presence of plane wave and localized sources. For this purpose, an approximate analytical method is developed to characterize the reflection properties of a cylindrically curved FHIS. The effects of curvature on the reflection phase of the curved FHISs are examined. Furthermore, the effects of different types of currents, specifically the ones inherent to finite sized periodic structures, on the reflection phase characteristics are observed. After the reflection phase characterization of curved HISs, the performance of dipole antennas located in close proximity to a curved HIS are investigated, and the results are compared with the flat case. Different types of resonances that may occur for such a low-profile antenna application are discussed. The effects of curvature on the radiation performance of antennas are examined. Commercially available flexible materials are relatively thin which degrades the bandwidth of HISs. Another practical aspect, which is related to the substrate thickness, is the compactness of the surface. Because of the design limitations of conventional HISs, it is not possible to miniaturize the HIS and increase the bandwidth, simultaneously. To overcome this drawback, a novel HIS is proposed with a periodically perforated ground plane. Copper plated through holes are extremely vulnerable to bending and should be avoided at the bending parts of flexible circuits. Fortunately, if designed properly, the perforations on the ground plane may result in suppression of surface waves. Hence, metallic posts can be eliminated without hindering the surface wave suppression properties of HISs. / Dissertation/Thesis / Ph.D. Electrical Engineering 2013