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京都大学 / 新制・課程博士 / 博士(工学) / 甲第23927号 / 工博第5014号 / 新制||工||1783(附属図書館) / 京都大学大学院工学研究科合成・生物化学専攻 / (主査)教授 松田 建児, 教授 杉野目 道紀, 教授 生越 友樹 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

京都大学 / 新制・課程博士 / 博士(工学) / 甲第24640号 / 工博第5146号 / 新制||工||1983(附属図書館) / 京都大学大学院工学研究科合成・生物化学専攻 / (主査)教授 杉野目 道紀, 教授 生越 友樹, 教授 松田 建児 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

Full 360 degree 3D finite element models are the most complete representation of Oil Country Tubular Goods (OCTG) premium threaded connections. Full 3D models can represent helical threads and boundary conditions required to simulate make-up and service loading. A methodology is developed to create a 360 degree full 3D parametric finite element model with helical threads as an effective design and analysis tool. The approach is demonstrated with the creation of a metal-to-metal seal integral joint full 3D model with manufacturer supplied geometry. The premium connection is decomposed into smaller parts to generate parametric geometric features. A controlled parametric meshing scheme is developed to manage mesh density in contact regions to effectively represent the mechanics in regions of interest while minimizing total element count. The scripted parametric approach allows for efficient geometric and mesh updates. Several methods to reduce and manage model runtimes are presented. An elastic-plastic material model is created with material coupon tensile tests results. Digital Image Correlation (DIC) is used to measure full-field displacement and strain data on the surface of the box. Experimental set up and data processing procedures are discussed. Error metrics are developed to correlate the finite element model results with the DIC experimental data. The DIC make-up experimental results are used to reconcile the finite element model to develop a minimum error make-up model relative to the pin rotation. The friction coefficient is estimated and the make-up torque-turn behavior is verified. The calibrated 3D finite element model is validated with ISO_13769 load series B axial and internal pressure loading experimental DIC data. Metal-to-metal seal metrics of contact pressure and seal length are evaluated. / Master of Science

Yes / Condensation of a pyridyl-2-carbaldehyde derivative with 2-(bromoethyl)amine hydrobromide gave tetracyclic pyrido[1,2-a]pyrido[1’,2’:3,4]imidazo-[2,1-c]-6,7-dihydropyrazinium dications in excellent yields. Crystal structures and NOE data demonstrated the helical character of the dications, the dihedral angles between the two pyrido groups ranging from 28–458. An intermediate in the synthesis was also characterized. A much brighter emission compared to literature helicenes has been found, with quantum yields as high as 60% in the range of l=460– 600 nm. Preliminary cytotoxicity studies against HT-29 cancer cells demonstrated moderate-to-good activity, with IC50 values 12–30x that of cisplatin.

Helices are broadband antennas that provide moderate gain, largely real input impedance and circular polarization when operating in the axial mode regime. A modified form of the helix, the spherical helix, has been shown to yield similar polarization and gain characteristics over a narrow bandwidth but a much larger beamwidth. This investigation examines multifilar hemispherical helices and produces two specific designs with some desirable radiation characteristics. The side-fed quadrifilar helix and the top-fed bifilar helix are the new hemispherical designs which are studied in detail both numerically and experimentally. The Numerical Electromagnetics Code 4 is used to analyze the radiation characteristics of the proposed multifilar hemispherical helices. Directivity, E- and H-plane radiation patterns, axial ratio and input impedance of a few example designs are calculated. Measurements, taken in the anechoic chamber at the Virginia Tech antenna range, generally confirmed the simulation results. It is shown that the bifilar hemispherical helix provides a flat gain curve over the measured bandwidth (~14%) and generally elliptical polarization with near circular polarization in limited case. / Master of Science

Als Basis der Positronenquelle zur Erzeugung polarisierter Positronen bei einem zukuunftigen internationalen Linearkollider ist ein helikaler Undulator vorgesehen. Das E-166 Experiment testete diese Methode unter Benutzung eines ein Meter langen, kurzperiodischen, gepulsten helikalen Undulators im Final Focus Test Beam (FFTB) am SLAC. Ein 46.6 GeV Elektronenstrahl mit geringer Emittanz wurde durch diesen Undulator gefuehrt und erzeugte zirkular polarisierte Photonen mit einer Energie bis zu ungefaehr 8 MeV. Diese wiederum konvertierten in einem relativ duennen Target zu longitudinal polarisierten Positronen. Die Polarisation der Positronen wurde bei 5 verschieden Positronenergien gemessen. Zusaetzlich ist die Polarisation von Elektronen fuer einen Energiepunkt gemessen worden. Um die gemessenen Asymmetrien mit den Erwartungen vergleichen zu koennen, waren detaillierte Simulationen noetig. Dies erforderte die Erweiterung von von GEANT4 um die wichtigsten polarisationsabhaengigen Wechselwirkungen von Elektronen, Positronen und Photonen mit Materie. Die gemessene Positronpolarisation stimmt mit den Erwartungen ueberein und betraegt fuer den Energiepunkt mit der hoechsten Polarisation von 6 MeV mehr als 80 prozent. / A helical undulator based polarized positron source is forseen at a future International Linear Collider. The E-166 experiment has tested this scheme using a one meter long, short-period, pulsed helical undulator installed in the Final Focus Test Beam (FFTB) at SLAC. A low-emittance 46.6 GeV electron beam passing through this undulator generated circularly polarized photons with energies up to about 8 MeV. The generated photons of several MeV with circular polarization are then converted in a relatively thin target to generate longitudinally polarized positrons. Measurements of the positron polarization have been performed at 5 different energies of the positrons. In addition electron polarization has been determined for one energy point. For a comparison of the measured asymmetries with the expectations detailed simulations were necessary. This required upgrading GEANT4 to include the dominant polarization dependent interactions of electrons, positrons and photons in matter. The measured polarization of the positrons agrees with the expectations and is for the energy point with the highest polarization at 6 MeV about 80 percent.

This thesis entitled “Design and Synthesis of Peptidomimics Constrained in Helical and Sheet Conformations Using a Novel Covalent Surrogate for the Peptide Main Chain Hydrogen Bond” is divided into six chapters. Chapter 1: Introduction to Ordered Conformations of Peptides and Strategies for Constraining Short Peptides in Ordered Conformations. The first chapter describes the different types of protein secondary structures and introduces the various prominent strategies developed thus far to constrain short peptides in ordered secondary structure-like conformations, with specific emphasis on helical and parallel β-sheet folds. Chapter 2: Design of Structure and General Methodology for the synthesis of Novel H-Bond Surrogate Constrained Cyclic α-Helical Mimics Here we develop the first design of the propyl linker as a covalent surrogate for the peptide H-bond. The first synthetic methodology is described for the synthesis of constraining shortest peptide sequences (tripeptides) in α-helix-like conformations. The Macrolactamization strategy proved to work best as the final step for cyclization. All residues of the turn are completely retained in the constrained sequence, unlike any other earlier method. More importantly, there are no metal involved as catalysts in any of the synthetic transformations, hence removing the problem of metal-bound cyclic structures – which have otherwise rendered these structures non-usable as drug leads in the earlier models. Gly-rich peptides have been constrained as extreme cases of highest chain entropy and least helix propensity. Both secondary and tertiary amide containing peptides have been synthesized using this protocol. Note that the macrolactamization was found to be better than the Fukuyama-Mitsunobu N-alkylation protocol for the final cyclization step. Chapter 3: Synthesis of C-terminal Extended HBS-Constrained Helical Turn Mimics – Validation of the Versatility of Current synthetic protocol The developed cyclization protocol is extended towards the synthesis of C-terminal extended α-helical turn mimics using a solution phase peptide synthesis procedure. Peptides which extend belong the helical turn by a high entropy Gly-residue at the C-terminal are synthesized. The versatility of the synthetic methodology to accommodate sterically constrained amino acid residues – in the form of phenylalanine residue – at any of the positions i+1, i+2 or i+3 of the constrained helical turn is demonstrated. The synthesized are easily isolated without need for column chromatography, in high purity and good yields – this is due to the presence of the N-terminal amino group, salts of which are easily triturated to remove all other organic impurities. Chapter 4: Synthesis and CD conformational analyses of HBS constrained α-Helical turn mimics containing residues with improved helical propensities Alanine residue has the highest helix propensity among all other natural α-amino acid residues. Its enthalpic contribution to the helical conformation is 1 kcal/mol more than that for the Gly residue, which has the least propensity. Incorporation of Ala residue in the Gly-rich cyclic sequences in either the middle of constrained tripeptide or as the C-terminal extended residue has been accomplished. Comparison of the CD spectra of the synthesized cyclic α-helical turn peptides reveals that a tertiary amide linkage is essential for the propyl linker at the C-terminal amino appendage, for helicity to be observed. Helicity improves upon introduction of the first extended residue. The constrained and C-terminal extended α-helical turn mimics show consistently high helicity irrespective of the helix propensities of the component residues showing that the covalent propyl linker surrogate for the H-bond overwhelms the natural propensities of individual amino acid residues towards enabling stabilization of the helical turn and offer far better structural organization to this cause. Chapter 5: Synthesis of shortest HBS-constrained 310 and - helical peptide analogues The unique versatility of the novel covalent propyl linker surrogate for the peptide H-bond is exhibited by its ability to constrain dipeptides in 310-helix like structures. This is the first and the only HBS model that can achieve this synthetic target as the synthetic protocol allows the conservation of both the residues as is in the constrained helical turn. Similarly, the trapping of a pentapeptide in a C-terminal extended rare and unstable -helix like cyclic structure using the current HBS linker is achieved. Considering the high entropic cost for cyclizing such a long 16-membered chain into a constrained structure, this again exhibits the versatility of the currently developed HBS design and the currently developed synthetic methodology. Chapter 6: First design and synthesis of novel H-bond surrogate constrained parallel β-sheet mimics H-bonding interactions stabilize another prevalently observed secondary structure, other than helical structures, namely the -sheets. The parallel -sheets that almost qualify for super secondary structures due to the high contact orders in them are thought to mimic in models, unlike the easier antiparallel -sheets. Here we replace the inter-strand peptide H-bond between parallel -strands to create excised templates as parallel -sheet nucleators. The propyl linker acts as a dynamic linker in these models and the two amino groups are protected with bulky sulphonamides, in order to provide Thorpe-Ingold effect to the peptide chain. The protocol for synthesizing these models has been described and the different analogues that are synthesized thus have been described. This is the first instance of synthesis of parallel -sheet mimics using the covalent surrogates for the peptide H-bond.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19012号 / 工博第4054号 / 新制||工||1624(附属図書館) / 31963 / 京都大学大学院工学研究科高分子化学専攻 / (主査)教授 赤木 和夫, 教授 辻井 敬亘, 教授 古賀 毅 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

Na prática de fundações por estacas helicoidais submetidas a esforços de tração (também conhecidas como ancoragens helicoidais) frequentemente são observadas discrepâncias entre valores de capacidade de carga previstos por métodos teóricos e medidos em provas de carga. Entre outros fatores, estas diferenças ocorrem pelo fato de nenhum dos métodos teóricos existentes considerarem adequadamente o efeito da instalação no comportamento deste tipo de ancoragem. Durante a penetração por rotação das hélices da estaca/ancoragem no terreno, os parâmetros de resistência e de rigidez do solo penetrado, e as tensões radiais em torno da estaca são modificados. O nível de degradação do solo que suportará as cargas aplicadas na ancoragem é dependente do tipo e características do solo, e do número e geometria das hélices. Diante deste cenário de incertezas provenientes do efeito da instalação, duas distintas abordagens probabilísticas são apresentadas nesta dissertação. A primeira abordagem tem o intuito de verificar o efeito da variabilidade de distintas variáveis influentes no comportamento de ancoragens helicoidais. Para este fim, foi utilizado o método de expansão em Polinômio de Caos, baseado na modelagem numérica de ancoragens helicoidais em areia, calibrada com os resultados medidos em modelos testados em centrifuga. Foi verificado nesta parte o nível de influência de cada parâmetro de entrada do solo no comportamento carga x deslocamento da ancoragem. No segundo enfoque, foi proposto e avaliado um modelo probabilístico para simular a curva carga x deslocamento, obtida em provas de carga. Nesta parte, foi realizada uma análise de confiabilidade para verificação do estado limite de serviço de ancoragens helicoidais baseada em resultados de provas de carga executadas no Brasil. São também apresentadas nesta análise as incertezas provenientes da variabilidade do fator de torque utilizado na verificação da capacidade de carga durante a instalação da ancoragem. / Discrepancies between predicted and measured results of uplift capacity of helical piles (or helical anchors) have been commonly observed in the practical experience. Among other factors, these differences occur because the existing theoretical methods do not consider adequately the installation effect on the behavior of this type of anchor. During the anchor installation, the penetration by rotation of the helical plates into the ground modifies the soil strength and stiffness parameters, and the radial stresses around the pile. The degradation degree of the soil penetrated is dependent on the type and characteristics of the soil, and also on the number and geometry of helices. Against this background of uncertainty due to the installation effect, two different probabilistic approaches are presented in this dissertation. The first approach is used to verify the effect of the variability of different influential variables on the behavior of helical anchors. For this purpose, the probabilistic method named Sparse Polynomial Chaos Expansion was used, based on the numerical modeling of helical anchors in sand, calibrated with measured results obtained from reduced models tested in centrifuge. As a result, the level of influence of each soil input parameter on the anchor load-displacement behavior is presented. In the second approach, a probabilistic model to simulate the load-displacement curve obtained in load tests was proposed and evaluated. For this part, a reliability analysis was performed to check the serviceability limit state of helical anchors, based on the results of field load tests performed in Brazil. In addition, the uncertainties arising from the variability of the torque factor were evaluated. The torque factor is frequently used to verify the uplift capacity of helical anchors during installation.