京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21359号 / 工博第4518号 / 新制||工||1703(附属図書館) / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 岸田 潔, 教授 三村 衛, 教授 木村 亮 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

No description available.

Fractures and fracture networks govern the mechanical and fluid flow behavior of rock masses. Tunneling and other rock mechanics applications therefore require the characterization of rock fractures based on geological data. Field investigations produce only a limited amount of data from boreholes, outcrops, cut slopes, and geophysical surveys. In tunneling, the process of excavation creates a priceless opportunity to gather more data during construction. Typically, however, these data are not utilized due to the impedance of sampling and analysis on the flow of construction, and safety concerns with sampling within unlined tunnel sections. However, the use of this additional data would increase the overall safety, quality, and cost savings of tunneling. This study deals with several aspects of the above, with the goal of creating methods and tools to allow engineers and geologists to gather and analysis fracture data in tunnels without interrupting the excavation and without compromising safety. Distribution-independent trace density and mean trace length estimators are developed using principles of stereology. An optimization technique is developed utilizing Differential Evolution to infer fracture size and shape from trace data obtained on two or more nonparallel sampling planes. A method of producing nearly bias free empirical trace length CDF's is also introduced. These new methods and tools were validated using Monte Carlo simulations. A field study was conducted in an existing tunnel allowing the above methods and tools to be further validated and tested. A relational database was developed to aid in storage, retrieval, and analysis of field data. Fracture models were built and updated using fracture data from within the tunnel. Utilization of state of the art imaging techniques allowed for remote sampling and analysis, which were enhanced by the use of 3d visualization techniques. / Ph. D.

Two instruments mounted in a piggyback arrangement were developed for time-resolved measurements of dynamic flow quality in a transonic cryogenic wind tunnel. The first one is a dual hot-wire aspirating probe for measurement of stagnation pressure and temperature. The second is a miniature high-frequency response angle probe consisting of surface mounted pressure sensors. The aspirating probe was tested in the 0.3-m Transonic Cryogenic Tunnel (TCT) at NASA-Langley Research Center. Stagnation pressure and temperature measurements were taken in the free-stream of the settling chamber and test section. Data were also obtained in the unsteady wake shed from an airfoil oscillating at 5 Hz. The investigation revealed the presence of large stagnation pressure and temperature fluctuations in the settling chamber occurring at the blade passing frequency of the tunnel driving fan. The fluctuations in the test section are of a much more random nature and have amplitudes much lower than those in the test section. The overall results are consistent with previous tunnel disturbance measurements in the 0.3-m TCT. In the unsteady wake shed from the oscillating airfoil, stagnation temperature fluctuations as high as 42 K rms were observed. The high-frequency angle probe is a four sensor, pyramid type probe capable of simultaneously measuring time resolved stagnation and static pressures and two orthogonal flow angles. Using measurements from both probes, all flow parameters of interest can be deduced. Aerodynamic behavior of a full size model of the probe was established in an open air jet of known conditions. / M.S.

Most vehicular tunnels, due to their restrictive and confined environment require continuous traffic surveillance and control. This is achieved by a variety of systems like closed circuit TV monitoring, personnel stationed in the tunnel, overheight & speed detectors and others. Traffic flow data were obtained from the Interstate 64(I -64) Hampton Roads Bridge-Tunnel. The data were analyzed and conclusions were drawn about traffic flow behavior at the different tunnel sections. During the operation of a tunnel, capacity reductions are often experienced due to temporary lane closures. These could result from incidences occurring in the tunnel area or due to regular maintenance activities. This work concentrates on the former case. A microcomputer model called Queue and User Cost Evaluation of Work Zones(QUEWZ) was employed in studying lane closure scenarios for the Virginia Tidewater Area Tunnels. In case of significant capacity reductions or complete blockages of directions of travel, it is desired to know beforehand the impact expected on the surrounding network. Traffic management actions like rerouting policies could be implemented and thus alleviate the problem. MASSVAC2, a computer simulation model for mass evacuation under emergency conditions was employed for analyzing different traffic management scenarios. / M.S.

L’ensemble des mines – et particulièrement celles exploitant un gisement filonien ou de faible puissance – sont très sensibles à la problématique de la dilution minière (i.e ., bris hors-profil de l’éponte supérieure). En effet, puisque cette dilution est généralement de faible teneur, le matériel qui se retrouve dans les chantiers miniers peut ne pas permettre de compenser les coûts associés au minage et par conséquent, la rentabilité de l’opération peut en être affectée. Ceci est particulièrement vrai lorsque la teneur de la dilution se situe sous le seuil de rentabilité (i.e., teneur de coupure). Par ailleurs, lorsque des effondrements (dilution) surviennent pendant les activités de soutirage, ceci représente un risque important pour les équipements mobiles (e.g., chargeuse-navette). Nombreux sont les chercheurs qui ont travaillé à développer et à améliorer les abaques de stabilité et critères de conception de chantiers, mais leur efficacité à prédire le bris hors-profil est souvent faible. Néanmoins, ces outils demeurent très utiles pour les projets sur sites vierges (« greenfield projects »), mais dès lors que les conditions géomécaniques d’un site deviennent mieux comprises, il importe de corriger et d’optimiser ces critères de conception afin de mieux représenter la réalité de l’opération minière. Ce mémoire expose donc la méthodologie employée afin de quantifier le bris hors-profil provenant des différentes surfaces des chantiers (i.e., épontes, toit, murs) exploités par la méthode de chambre vide. Une comparaison entre les performances réelles et celles prédites par les modèles couramment utilisés dans l’industrie a été effectuée. À l’aide de méthodes statistiques univariées et bivariées, les paramètres affectant le bris hors-profil peuvent être déterminés objectivement. L’élaboration de nouveaux modèles statistiques permet également d’accroître la fiabilité des prédictions (i.e., le bris hors-profil) et fournit des outils permettant d’assister les ingénieurs dans la conception et le dimensionnement des chantiers miniers. La mine Éléonore de Goldcorp a servi de cas d’étude afin de démontrer la validité d’une telle démarche.

Το ριβόσωμα παρέχει την πλατφόρμα πάνω στη οποία το mRNA αναγνωρίζεται και αποκωδικοποιείται από τα μεταφορικά RNAs. Δρα καταλυτικά ως ριβοένζυμο και συνθέτει την αντίστοιχη αλληλουχία αμινοξέων. Σημαντικά λειτουργικό κομμάτι του ριβοσώματος αποτελεί το τούνελ εξόδου, το οποίο βρίσκεται στη μεγάλη υπομονάδα του ριβοσώματος και αποτελεί το κανάλι, μέσω του οποίου οι νεοσυντιθέμενες πεπτιδικές αλυσίδες εξέρχονται στο κυτταροδιάλυμα. Νεότερες ερμηνείες προσδίδουν στο τούνελ εξόδου έναν πιο ενεργό ρόλο, καταδεικνύοντας τη σπουδαιότητά του όχι μόνο ως διάδρομος εξόδου της πεπτιδικής αλυσίδας, αλλά και ως λειτουργική περιοχή του ριβοσώματος με σημαντικό ρόλο στη ρύθμιση της πρωτεϊνικής σύνθεσης. Το δίκτυο επικοινωνίας μεταξύ τούνελ και πεπτιδυλοτρανσφεράσης δεν έχει ακόμα χαρτογραφηθεί και μελετηθεί πλήρως, υπάρχουν όμως μέχρι στιγμής πολυπληθείς αναφορές που επιβεβαιώνουν ότι μέρος του αποτελούν κυρίως βάσεις του 23S rRNA, συστατικά του τοιχώματος της εισόδου στο τούνελ, και βάσεις ευρισκόμενες στο κέντρο της πεπτιδυλοτρανσφεράσης, συντηρημένες εξελεικτικά, γνωστές από την αλληλεπιδρασή τους με αναστολείς της πεπτιδυλοτρανσφεράσης και κυρίως με αναστολείς της οικογένειας των μακρολιδίων. Στην παρούσα διατριβή μελετήσαμε την αλληλεπίδραση των χαρακτηριστικών αυτών βάσεων που συγκροτούν το δίκτυο επικοινωνίας μεταξύ του τούνελ εξόδου και της πεπτιδυλοτρανσφεράσης με τη βοήθεια νέων μακρολιδίων τρίτης γενιάς, των κετολιδίων, που φέρουν επί πλέον και άτομα φθορίου, παρέχοντας έτσι στο μόριο μεγαλύτερη συγγένεια για φορτισμένες ομάδες. Σύμφωνα με τα αποτελέσματά μας, αποτελούν εξαιρετικά υποσχόμενους αντιμικροβιακούς θεραπευτικούς παράγοντες, και αναστέλλουν ισχυρά την μετάφραση. Παράλληλα καταλαμβάνουν αμοιβαία αποκλειόμενες θέσεις στο ριβόσωμα, στην είσοδο του τούνελ, αλληλεπιδρώντας με τις βάσεις Α2058, Α2059, Α2062 και Α752. Επειδή όλες οι παραπάνω βάσεις αποτελούν μέρος του δικτύου επικοινωνίας τούνελ-πεπτιδυλοτρανσφεράσης, θα μπορούσαμε να συμπληρώσουμε τον ήδη υπάρχοντα μηχανισμό δράσης των μακρολιδίων (drop-off, λόγω αύξησης της koff) με την επικοινωνία του τούνελ με την πεπτιδυλοτρανσφεράση, ώστε να απενεργοποιηθεί η τελευταία με τελική κατάληξη τη διακοπή της πρωτεϊνικής σύνθεσης και την επαγωγή του drop-off. Για την περαιτέρω μελέτη της αλληλεπίδρασης του τούνελ με την νεοσυντιθέμενη πεπτιδική αλυσίδα, σχεδιάσθηκαν νέα πεπτιδυλο παράγωγα της χλωραμφανικόλης, τα οποία προσομοιάζουν πεπτιδυλο-tRNAs προσδεδεμένα στην Α-θέση του ριβοσώματος, με την ολιγοπεπτιδική αλληλουχία να εκτείνεται βαθύτερα στο τούνελ, υιοθετώντας μία ανοικτή διαμόρφωση. Όπως διαπιστώσαμε με συναγωνιστικές μελέτες με ραδιενεργό ερυθρομυκίνη, τα συγκεκριμένα ανάλογα καταλαμβάνουν την Α-θέση στο κέντρο της πεπτιδυλοτρανσφεράσης, ενώ η συγγένεια του κάθε αναλόγου ως αναστολέα της λειτουργίας του ριβοσώματος, είναι απόλυτα ιδιοσυγκρατική, καθώς εξαρτάται από την αλληλουχία των αμινοξέων που συγκροτούν το πεπτίδιο. Μελετώντας το αποτύπωμα των ενώσεων αυτών στο ριβόσωμα, διαπιστώσαμε ότι ενώ η βάση της χλωραμφαινικόλης διατηρεί τη θέση της στη περιοχή Α, το πεπτίδιο εισέρχεται βαθειά στην είσοδο του τούνελ, αλληλεπιδρώντας με την βάση Α752. Συνεπώς τα πεπτιδυλο ανάλογα της χλωραμφαινικόλης, τα οποία συμπεριφέρονται ως ισχυροί αναστολείς της μετάφρασης, αποτελούν κατάλληλα εργαλεία μελέτης της αλληλεπίδρασης μεταξύ της νεοσυντιθέμενης πεπτιδικής αλληλουχίας και στοιχείων του τούνελ εξόδου του ριβοσώματος. / Ribosomes translate the genetic code into proteins in all living cells with extremely high efficiency, owing to their inherent flexibility and to their spectacular architecture. These large ribonucleoprotein particles synthesize proteins in all cells, using messenger RNA as the template, confirming that the ribosome is indeed a ribozyme, and aminoacyl-transfer RNAs as substrates. As the nascent polypeptide chain is being synthesized, it passes through a tunnel within the large ribosomal subunit and emerges at the solvent side where protein folding occurs. New studies indicate that in some cases, the tunnel plays a more active role. Accumulated evidence had definitely concluded that ribosomal tunnel is not only a passive conduit for the nascent chains but a rather functionally important compartment, where specific peptide sequences establish direct interactions with the tunnel, talking back to the ribosome in order to regulate peptide synthesis, leading to translational stalling. In this study, we have investigated functional interactions between distinct locations of the ribosomal tunnel and specific residues of the peptidyltransferase, using new macrolides, known as ketolides, which carry also fluorine attached to the lactone ring either directly or indirectly. According to our results, the new antibiotics exhibited better antimicrobial activity, inhibiting strongly the translational apparatus and could be useful tools in the future for treatment of bacterial infections. Binding studies with radiolabeled erythromycin revealed that these drugs bound competitively with erythromycin at the large ribosomal subunit, with extremely low dissociation constants. In parallel, RNA footprinting indicated that the new ketolides occupy the main macrolide binding site in the ribosome, which is located at the entrance of the exit tunnel adjacent to the peptidyltransferase center. These drugs interact with A2058, A2059 and A2062, as well as their extended heteroaromatic alkyl-aryl side chain penetrates deeper in the tunnel protecting A752 of Helix 35, interacting with basepair A752-U2609. To explore further this interaction, we have synthesized new peptidyl conjugates of chloramphenicol, which resemble nascent peptidyl-tRNA chains bound to the A-site of the ribosome, with their peptide sequence located deeper within tunnel, adopting an extended configuration. According to our data, these compounds did indeed bind to the peptidyl transferase center, competing with radiolabelled- chloramphenicol for binding to the ribosome. The binding of each analog, as well as its inhibitory activity of ribosomal function, is absolutely idiosyncratic, depending on the sequence of amino acid of peptide moiety. Studying the footprinting pattern of these compounds on the ribosome, we confirmed that while the chloramphenicol base maintains its position on the A-site, the peptide moiety penetrates deeper in the entrance of the exit tunnel, interacting with nucleotide A752. Therefore, we believe that these chloramphenicol peptides could be useful tools for probing nascent polypeptide chain interaction with the ribosome.

Highly loaded single stage gas turbines are being developed to minimize the turbine size and weight. Such highly loaded turbines often result in transonic flows, which imply a reduction in the efficiency due to the shock losses. The efficiency of a turbine is defined as the ratio between the real work extracted by the turbine rotor from the fluid and the maximum available enthalpy for a given pressure ratio. The relationship between turbine performance and design parameters is not yet fully comprehended due to the complexity of the flow field and unsteady flow field interactions. Hence, experimental and numerical studies remain necessary to understand the flow behavior at different conditions to advance the state of the art of the prediction tools. The purpose of the current research is to develop a methodology to determine the efficiency with an accuracy better than 1 % in a cooled and uncooled high pressure (HP) turbine tested in a short duration facility with a running time of about 0.4s. Such low level of uncertainty requires the accurate evaluation of a large number of quantities simultaneously, namely the mass flow of the mainstream, the coolant, and leakage flows properties, the inlet total pressure and total temperature, the stage exit total pressure, the shaft power, the mechanical losses and the heat transfer. The experimental work is carried out in a compression tube facility that allows testing the turbine at the temperature ratios, Re and Mach numbers encountered in real engines. The stage mass flow is controlled by a variable sonic throat located downstream of the stage exit. Due to the absence of any brake, the turbine power is converted into rotor acceleration. The accurate measurement of this acceleration as well as those of the inertia and the rotational speed provides the shaft power. The inertia of the whole rotating assembly was accurately determined by accelerating and decelerating the shaft with a known energy. The mass-flow is derived from the measured turbine inlet total pressure and the vane sonic throat. The turbine sonic throat was evaluated based on a zero-dimensional model of the turbine. The efficiencies of two transonic turbines are measured at design and off-design conditions. The turbine design efficiency is obtained as 91.8 %. The repeatability of the measurements for 95% confidence level varies between 0.3 % and 1.1 % of the efficiency depending on the test case. The theoretical uncertainty level of 1.2 % is mainly affected by the uncertainty of exit total pressure measurements. Additionally, the effect of vane trailing edge shock formations and their interactions with the rotor blade are analyzed based on the experimental data, the numerical tools and the loss correlations. The changes of blade and vane performances are measured at mid-span for three different pressure ratios which influence the vane and rotor shock mechanisms. Moreover, the unsteady forces on the rotor blades and the rotor disk were calculated by integration of the unsteady static pressure field on the rotor surface.

Approved for public release, distribution is unlimited / For over half a century the NPS Aerolabʼ Low Speed Wind Tunnel located in Halligan Hall of the Naval Postgraduate school has served to provide students and faculty with meaningful aerodynamic data for research and problem analysis. New data acquisition hardware was installed three years ago but never fully verified, and contained no integrated software program to collect data from the strain-gauge balance pedestal. Existing National Instruments based hardware for the NPS low-speed wind tunnel was reconfigured to obtain data from the strain-gauge pedestal. Additionally, a data acquisition software program was written in LabVIEW⠭ to accommodate the hardware. The Virtual Instruments (VI) program collects and plots accurate data from all four strain gauges in real-time, producing non-dimensional force and moment coefficients. A research study on the performance of an OH-6A helicopter fuselage was conducted. NPS Aerolabʼ wind tunnel tests consisted of drag, lift, and pitching moment measurements of the OH-6A along yaw and angle-of-attack sweeps. The results of the NPS wind tunnel data were compared against testing conducted on a full-scale OH-6A helicopter in NASA Ames' 40 ft. x 80ft. wind tunnel, along with the U.S. Army's Light Observation Helicopter (LOH) wind tunnel tests. Results of current testing substantiate the LabVIEW⠭ code. / Ensign, United States Navy

O método dos elementos de contorno (MEC) surgiu como uma poderosa alternativa ao método dos elementos finitos (MEF) principalmente em casos como problemas de concentração de tensões ou onde o domínio se estende para o infinito. Em virtude das potencialidades já identificadas do MEC para a solução de problemas da geotecnia, em especial para problemas de túneis, este trabalho tem como objetivo desenvolver um programa que seja capaz de analisar as variáveis envolvidas na construção de túneis profundos através de um modelo numérico bidimensional baseado no MEC, implementando técnicas numéricas tais como: subelementação, técnica da sub-região e modelagem de inclusão e enrijecedores. O modelo numérico bidimensional foi calibrado para considerar o efeito tridimensional do problema de túneis no que se refere ao avanço da frente de escavação, para dois casos a saber: i) túneis sem suporte e ii) túneis com suporte. Os resultados mostraram grande precisão quando comparados com os resultados analíticos mesmo utilizando um número pequeno de elementos, provocando uma redução significativa no tempo de processamento se comparado com outros métodos. A técnica da subelementação produziu uma suavização nos resultados dos pontos internos localizados muito próximos do contorno. A técnica da sub-região, bem como a modelagem de inclusão e enrijecedores apresentaram resultados consistentes dando ao programa uma versatilidade maior. Na calibração dos parâmetros para a consideração do efeito tridimensional na escavação de túneis sem suporte, foi proposto o método da redução do carregamento com a construção do perfil de deformação longitudinal do túnel - LDP (Longitudinal Deformation Profile). Para a escavação de túneis com suporte foram propostos quatro métodos de análise: i) método da redução do carregamento sobre o túnel, ii) método da redução de rigidez do suporte, iii) método do acréscimo do carregamento sobre o túnel e iv) método do alívio de carga sobre o suporte. Todos esses métodos foram desenvolvidos a partir do modelo Kappa (\'kapa\'), elaborado neste trabalho a partir dos resultados encontrados na simulação numérica tridimensional realizado nos programas BEFE e BEFE++, e comparado com o modelo de Schwartz e Einstein. Por fim, o método para a construção do gráfico de deslocamento radial para túneis circulares suportados, considerando o atraso na instalação do suporte, utilizando um método numérico ou resultado analítico do estado plano de deformação se mostra como uma alternativa simples para análise do efeito tridimensional contido no problema de túneis. / The boundary element method (BEM) has appeared as a powerful alternative to the finite element method (FEM) mainly in the cases where a good accuracy is required, as for problems with strain or stress concentration and problems with domain extending to infinite. The objective of this work is to develop a formulation and the corresponding computational code to analyse the variables in a design of deep tunnels, using a improved BEM two-dimensional numerical model, in which the following techniques were implemented: sub-elementation, sub-region technique, reinforcements introduced by modifying locally the domain rigidity. The two-dimensional model was calibrated to take into account the three-dimensional effects appearing around the tunnel face advance for two cases: i) tunnel without support and ii) tunnel with support. The results showed good accuracy when compared with analytical results even when obtained by using coarse discretizations and therefore requiring less computer time in comparison with other numerical procedures. The sub-elementation technique has smoothed the results for internal points near the boundary. The sub-region technique and the reinforcement inclusions lead to accurate making the computer code reliable. For the parameter calibration to take into account the three-dimensional effects applied to non lined tunnels the method of loading reductions was proposed obtaining a tunnel longitudinal deformation profile - LDP. For the excavation of lined tunnels four methods of analysis were proposed: i) load reduction model, ii) reduction support stiffness model, iii) additional load model, and iv) decrease of lining load model. All these methods were developed from the kappa (\'kapa\') model, developed in this work using three-dimensional results obtained by using the computational systems BEFE and BEFE++ and compared with the Schwartz-Einstein method. Finally the method used to build the radial displacement graphic for lined circular tunnels, taking into account the support insertion delay, using either a numerical method or plane strain analytical solutions, was developed.