Dissertations / Theses: 'Structural geometry'

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El, Ghawalby Heyayda. "Spectral geometry for structural pattern recognition." Thesis, University of York, 2011. http://etheses.whiterose.ac.uk/1525/.

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Graphs are used pervasively in computer science as representations of data with a network or relational structure, where the graph structure provides a flexible representation such that there is no fixed dimensionality for objects. However, the analysis of data in this form has proved an elusive problem; for instance, it suffers from the robustness to structural noise. One way to circumvent this problem is to embed the nodes of a graph in a vector space and to study the properties of the point distribution that results from the embedding. This is a problem that arises in a number of areas including manifold learning theory and graph-drawing. In this thesis, our first contribution is to investigate the heat kernel embedding as a route to computing geometric characterisations of graphs. The reason for turning to the heat kernel is that it encapsulates information concerning the distribution of path lengths and hence node affinities on the graph. The heat kernel of the graph is found by exponentiating the Laplacian eigensystem over time. The matrix of embedding co-ordinates for the nodes of the graph is obtained by performing a Young-Householder decomposition on the heat kernel. Once the embedding of its nodes is to hand we proceed to characterise a graph in a geometric manner. With the embeddings to hand, we establish a graph characterization based on differential geometry by computing sets of curvatures associated with the graph nodes, edges and triangular faces. The second contribution comes from the need to solve the problem that arise in the processing of a noisy data over a graph. The Principal difficulty of this task, is how to preserve the geometrical structures existing in the initial data. Bringing together several, distinct concepts that have received some independent recent attention in machine learning; we propose a framework to regularize real-valued or vector-valued functions on weighted graphs of arbitrary topology. The first of these is deduced from the concepts of the spectral graph theory that have been applied to a wide range of clustering and classification tasks over the last decades taking in consideration the properties of the graph \(p\)-Laplacian as a nonlinear extension of the usual graph Laplacian. The second one is the geometric point of view comes from the heat kernel embedding of the graph into a manifold. In these techniques we use the geometry of the manifold by assuming that it has the geometric structure of a Riemannian manifold. The third important conceptual framework comes from the manifold regularization which extends the classical framework of regularization in the sense of reproducing Hilbert Spaces to exploit the geometry of the embedded set of points. The proposed framework, based on the \(p\)-Laplacian operators considering minimizing a weighted sum of two energy terms: a regularization one and an additional approximation term which helps to avoid the shrinkage effects obtained during the regularization process. The data are structured by functions depending on data features, the curvature attributes associated with the geometric embedding of the graph. The third contribution is inspired by the concepts and techniques of the graph calculus of partial differential functions. We propose a new approach for embedding graphs on pseudo-Riemannian manifolds based on the wave kernel which is the solution of the wave equation on the edges of a graph. The eigensystem of the wave-kernel is determined by the eigenvalues and the eigenfunctions of the normalized adjacency matrix and can be used to solve the edge-based wave equation. By factorising the Gram-matrix for the wave-kernel, we determine the embedding co-ordinates for nodes under the wave-kernel. The techniques proposed through this thesis are investigated as a means of gauging the similarity of graphs. We experiment on sets of graphs representing the proximity of image features in different views of different objects in three different datasets namely, the York model house, the COIL-20 and the TOY databases.

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Davis, Robert Tucker. "Geometric Build-up Solutions for Protein Determination via Distance Geometry." TopSCHOLAR®, 2009. http://digitalcommons.wku.edu/theses/102.

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Proteins carry out an almost innumerable amount of biological processes that are absolutely necessary to life and as a result proteins and their structures are very often the objects of study in research. As such, this thesis will begin with a description of protein function and structure, followed by brief discussions of the two major experimental structure determination methods. Another problem that often arises in molecular modeling is referred to as the Molecular Distance Geometry Problem (MDGP). This problem seeks to find coordinates for the atoms of a protein or molecule when given only a set of pair-wise distances between atoms. To introduce the complexities of the MDGP we begin at its origins in distance geometry and progress to the specific sub-problems and some of the solutions that have been developed. This is all in preparation for a discussion of what is known as the Geometric Build-up (GBU) Solution. This solution has lead to the development of several algorithms and continues to be modified to account for more and different complexities. The culmination of this thesis, then, is a new algorithm, the Revised Updated Geometric Build-up, that is faster than previous GBU’s while maintaining the accuracy of the resulting structure.

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Bousfield, R. A. "Applications of differential geometry to structural mechanics." Thesis, University of Hertfordshire, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372544.

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Gabbrielli, Ruggero. "Foam geometry and structural design of porous material." Thesis, University of Bath, 2009. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.507759.

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Chiao, Ling-Yun. "Membrane deformation rate and geometry of subducting slabs /." Thesis, Connect to this title online; UW restricted, 1991. http://hdl.handle.net/1773/6814.

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Lyytik�inen, Katja Johanna. "Control of complex structural geometry in optical fibre drawing." University of Sydney. School of Physics and the Optical Fibre Technology Centre, 2004. http://hdl.handle.net/2123/597.

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Drawing of standard telecommunication-type optical fibres has been optimised in terms of optical and physical properties. Specialty fibres, however, typically have more complex dopant profiles. Designs with high dopant concentrations and multidoping are common, making control of the fabrication process particularly important. In photonic crystal fibres (PCF) the inclusion of air-structures imposes a new challenge for the drawing process. The aim of this study is to gain profound insight into the behaviour of complex optical fibre structures during the final fabrication step, fibre drawing. Two types of optical fibre, namely conventional silica fibres and PCFs, were studied. Germanium and fluorine diffusion during drawing was studied experimentally and a numerical analysis was performed of the effects of drawing parameters on diffusion. An experimental study of geometry control of PCFs during drawing was conducted with emphasis given to the control of hole size. The effects of the various drawing parameters and their suitability for controlling the air-structure was studied. The effect of air-structures on heat transfer in PCFs was studied using computational fluid dynamics techniques. Both germanium and fluorine were found to diffuse at high temperature and low draw speed. A diffusion coefficent for germanium was determined and simulations showed that most diffusion occurred in the neck-down region. Draw temperature and preform feed rate had a comparable effect on diffusion. The hole size in PCFs was shown to depend on the draw temperature, preform feed rate and the preform internal pressure. Pressure was shown to be the most promising parameter for on-line control of the hole size. Heat transfer simulations showed that the air-structure had a significant effect on the temperature profile of the structure. It was also shown that the preform heating time was either increased or reduced compared to a solid structure and depended on the air-fraction.

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Lyyttkäinen, Katja Johanna. "Control of complex structural geometry in optical fibre drawing /." Connect to full text, 2004. http://setis.library.usyd.edu.au/adt/public_html/adt-NU/public/adt-NU20041011.120247.

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Lyytikäinen, Katja Johanna. "Control of complex structural geometry in optical fibre drawing." Connect to full text, 2004. http://hdl.handle.net/2123/597.

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Thesis (Ph. D.)--University of Sydney, 2004.
Title from title screen (viewed 14 May 2008). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the School of Physics, Faculty of Science. Includes bibliographical references. Also available in print form.

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Dunne, Barry John. "Structural deformations in phosphorus and nitrogen complexes." Thesis, University of Bristol, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.346442.

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Medema, Guy Frederick. "Juan de Fuca subducting plate geometry and intraslab seismicity /." Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/6828.

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Aydin, Utkun. "A Structural Equation Modeling Study: The Metacognition-knowledge Model For Geometry." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608523/index.pdf.

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The purpose of this study is twofold: (1) to examine the effects of knowledge on cognition and regulation of cognition on declarative knowledge, conditional knowledge, and procedural knowledge in geometry and (2) to examine the interrelationships among declarative knowledge, conditional knowledge, and procedural knowledge in geometry. The reciprocal relationships between metacognitive and knowledge factors were modeled by using data from tenth grade secondary school students. Structural equation modeling was used to test the hypothesized relationships of two metacognitive factors (knowledge of cognition, regulation of cognition) and three knowledge factors (declarative knowledge, conditional knowledge, procedural knowledge). The observed variables representing the latent variables were determined by carrying out exploratory factor analysis and confirmatory factor analysis for the metacognitive awareness inventory and geometry knowledge test separately. Major findings revealed: (1) Declarative knowledge significantly and positively influences conditional and procedural knowledge
(2) Procedural knowledge has a signitificant and positive direct effect on conditional knowledge
(3) Declarative knowledge has a positive indirect effect on conditional knowledge
(4) Knowledge of cognition significantly and positively influences procedural knowledge
(5) Regulation of cognition has a significant but negative direct effect on procedural knowledge
(6) Knowledge of cognition has positive indirect effects on conditional and procedural knowledge
(7) Regulation of cognition has negative indirect effects on conditional and procedural knowledge
(8) Knowledge of cognition and regulation of cognition have non-significant direct effect on declarative and conditional knowledge. The results showed that knowledge of cognition has the strongest direct effect on procedural knowledge and the direct effect of declarative knowledge on conditional knowledge is stronger than on procedural knowledge. In view of the findings considerable suggestions is provided for teachers, instructional designers, and mathematics education researchers.

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Folster, Kaylee. "Influence of geometry on the dynamic behaviour of steel tubular towers for onshore wind turbines." Master's thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/25282.

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South Africa has recently experienced challenges regarding electricity consumption and availability. As part of the country's Integrated Resource Plan, these challenges are to be addressed. This involves a 20 year plan which aims to increase electricity supply capacity as well as reduce the reliance on coal power as part of the global trend to become more environmentally friendly. Wind power, specifically, is to account for a large portion of the renewable energy that is expected to become available by 2030. This results in the need for the understanding of wind turbine design by South African engineers. The dynamic analysis of wind turbine structures, is of particular interest to Civil Engineers. Wind turbine towers are recently of the monopole or tubular type tower, predominantly constructed of either concrete or steel or a combination of both. Steel tubular towers above a height of 80m are generally not recommended for wind turbines owing to cost concerns as well as difficulties in meeting dynamic behaviour requirements. Concrete towers and steel-concrete hybrid towers are recommended for this height regime. The aim of this study was to assess the prospective use of steel tubular towers of varying geometric shape for wind turbines with tower heights of 80m or greater. The study focussed on the analysis of natural frequency and assessing the applicability of steel tubular towers of geometric shapes that have not been previously explored or reported. The turbine of choice for this study was the Vestas V112 3MW type as this is one of the most commonly used and more efficient turbines for towers of this height regime. The results of this study showed that steel monopole towers of heights of 80m and more are still viable options for wind turbine towers. Various geometric tower cases of heights varying from 80m to 120m, produced acceptable fundamental natural frequencies within the allowable frequency range for a Vestas V112 3MW turbine.

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Cöllen, Liana. "Standardized Geometry Formats for AircraftConceptual Design and Physics-basedAerodynamics and Structural Analyses." Thesis, KTH, Aerodynamik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-121309.

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Cervera, Eva. "Evolutionary structural optimisation based on boundary element representation of B-spline geometry." Thesis, Durham University, 2003. http://etheses.dur.ac.uk/2004/.

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Evolutionary Structural Optimisation (ESO) has become a well-established technique for determining the optimum shape and topology of a structure given a set of loads and constraints. The basic ESO concept that the optimum topology design evolves by slow removal and addition of material has matured over the last ten years. Nevertheless, the development of the method has almost exclusively considered finite elements (FE) as the approach for providing stress solutions. This thesis presents an ESO approach based on the boundary element method. Non-uniform rational B-splines (NURBS) are used to define the geometry of the component and, since the shape of these splines is governed by a set of control points, use can be made of the locations of these control points as design variables. The developed algorithm creates internal cavities to accomplish topology changes. Cavities are also described by NURBS and so they have similar behaviour to the outside boundary. Therefore, both outside and inside are optimised at the same time. The optimum topologies evolve allowing cavities to merge between each other and to their closest outer boundary. Two-dimensional structural optimisation is investigated in detail exploring multi-load case and multi-criteria optimisation. The algorithm is also extended to three-dimensional optimisation, in which promising preliminary results are obtained. It is shown that this approach overcomes some of the drawbacks inherent in traditional FE-based approaches, and naturally provides accurate stress solutions on smooth boundary representations at each iteration.

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Lawson, K. D. "Thrust geometry and folding in the Alpine structural evolution of Haute Provence." Thesis, Swansea University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.637860.

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With the Haute Provence region of the external French Alps the internal zone Embrunais-Ubaye nappes rest with a shallow tectonic contact on the Dauphinois external zone. Beneath the Embrunais-Ubaye nappes, the external zone is deformed by south-west facing folds and by thrust faulting, the importance of which has only recently been recognised. The later emplacement of the Embrunais-Ubaye nappes towards the west into the area is generally thought to have been by gravity gliding. Detailed field studies within both the external zone and the Embrunais-Ubaye nappes has allowed the complex Alpine tectonic evolution of Haute Provence to be resolved. These studies have also shown the external zone deformation to be dominated by piggy-back thrust imbrication. A regional transport direction to the south-west and an overall external zone shortening of some 50% have been identified from the investigation of the three-dimensional geometry of thrust surfaces. The prominent south-west facing folds are found to have developed above a major decollement horizon and to have arcuate hinge lines concentric with the Castellane arc. Folds in general are in close association with thrust faults often developing passively as a response to thrust displacement. The Embrunais-Ubaya nappes consist of a number of thrust bounded structural units which have been emplaced into the region in an overstepping sequence. Detailed local mapping of the internal structure of these units has resulted in the identification of a major south-west directed shortening deformation of the Subbrianconnais zone dominated by thrust faulting. A restoration of Subbrianconnais structures gives an estimated north-east to south-west width for the Subbrianconnais zone of over 100km. Although the final emplacement of the Embrunais-Ubaye structural units may have been a superficial gravity gliding phenomenon, possibly as a result of tectonic uplift in the internal zones, the south-west directed thrust shortening of the external zone and probably the Subbrianconnais is the result of thrust displacements climbing from depth reflecting crustal shortening.

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Baker, Jonathan Mark. "Structural studies of water and ice in confined geometry by neutron diffraction." Thesis, University of Kent, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337073.

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Cobb, William Geoffrey Carnie. "Optimum holes in flat plates." Thesis, Imperial College London, 1987. http://hdl.handle.net/10044/1/38262.

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Irwin, Levi Jacob. "A new structural subclass of constrained geometry catalysts for the polymerization of olefins." Texas A&M University, 2005. http://hdl.handle.net/1969.1/3106.

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The sterically expanded octamethyloctahydrodibenzofluorene moiety, C29H38 (Oct), has been incorporated into ansa-metallocenes and constrained geometry catalysts (CGC's). Utilization of this sterically expanded version of fluorene has resulted in solidstate anomalies for both systems. The ansa-metallocenes Me2C(n5-C5H4) (n5-C29H36)MCl2, M = Zr, Hf and Me2C(n5-C5H4)(n5-C29H36)ZrBn2 demonstrate crystal motifs expected for ansametallocenes while Me2C(n5-C5H4)(n5-C29H36)MMe2, M=Zr, Hf exhibit diffuse diffraction, a phenomenon that is extremely unusual for organometallic complexes. This crystalline anomaly is the result of a disorder restricted to two dimensions caused by the rare pillared motif of the system. The best solution for this system consists of parallel and anti-parallel pillars present in a 60:40 ratio. The solid state anomaly observed for the Oct-CGC's occurs on a molecular level. The parent Oct-CGC, Me2Si(1-C29H36)(1-N-tBu)ZrCl2·OEt2, demonstrates an unprecedented n1 ligation to the fluorenyl-based ring. Systematic derivatization of this system via halide substitution, alkylation, and exchange of Zr for Hf has revealed that the n1 ligation persists for systems with small substituents on the metal center capable of retaining a coordinated ether. It is hypothesized that the unusual structure of this new Oct-CGC results in Me2Si(1-C29H36)(1-N-tBu)ZrCl2·OEt2/MAO (MAO = methylaluminoxane) being six times more active in the homopolymerization of 1-octene than ethylene. When compared to the prototypical Ti-CGC Me2Si(n5-C5Me4)(n1-N-tBu)TiCl2/MAO, the Oct-CGC is 85 times more reactive in the homopolymerization of 1-octene and 52 times more active in the copolymerization of 1-octene and 4-methyl-1-pentene. The high reactivity of the Oct-CGC towards alpha-olefins results in the observation of an unyielding comonomer effect in the copolymerization of these olefins with ethylene. In addition, the Oct-CGC is perhaps the most syndioselective catalyst known. With an enantiofacial selectivity of 99.7% and a remarkably high activity towards alpha-olefins, the Oct-CGC is capable of producing the highest melting syndiotactic polypropylene (Tm = 165oC, annealed = 174oC) reported thus far. The high activity and syndioselectivity of the Oct-CGC can be extended to the production of syndiotactic poly(4-methyl-1-pentene) with the highest melting point thus far reported (Tm = 215oC).

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Korla, Srikanth. "Inspection of Parts with Complex Geometry and Welds with Structural Health Monitoring Techniques." FIU Digital Commons, 2011. http://digitalcommons.fiu.edu/etd/460.

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Structural Health Monitoring (SHM) systems were developed to evaluate the integrity of a system during operation, and to quickly identify the maintenance problems. They will be used in future aerospace vehicles to improve safety, reduce cost and minimize the maintenance time of a system. Many SHM systems were already developed to evaluate the integrity of plates and used in marine structures. Their implementation in manufacturing processes is still expected. The application of SHM methods for complex geometries and welds are two important challenges in this area of research. This research work started by studying the characteristics of piezoelectric actuators, and a small energy harvester was designed. The output voltages at different frequencies of vibration were acquired to determine the nonlinear characteristics of the piezoelectric stripe actuators. The frequency response was evaluated experimentally. AA battery size energy harvesting devices were developed by using these actuators. When the round and square cross section devices were excited at 50 Hz frequency, they generated 16 V and 25 V respectively. The Surface Response to Excitation (SuRE) and Lamb wave methods were used to estimate the condition of parts with complex geometries. Cutting tools and welded plates were considered. Both approaches used piezoelectric elements that were attached to the surfaces of considered parts. The variation of the magnitude of the frequency response was evaluated when the SuRE method was used. The sum of the square of the differences was calculated. The envelope of the received signal was used for the analysis of wave propagation. Bi-orthogonal wavelet (Binlet) analysis was also used for the evaluation of the data obtained during Lamb wave technique. Both the Lamb wave and SuRE approaches along with the three methods for data analysis worked effectively to detect increasing tool wear. Similarly, they detected defects on the plate, on the weld, and on a separate plate without any sensor as long as it was welded to the test plate.

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Ayche, Nadim S. "The Effect of High Density Polyethylene (HDPE) Pipe Profile Geometry on its Structural Performance." Ohio University / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1127140719.

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Chai, Gin Boay. "The effect of geometry and prescribed delaminations on the postbuckling behaviour of laminated carbon-fibre reinforced plastic panels." Thesis, University of Strathclyde, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303278.

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Matthews, Chris. "The structural geometry of the Onkaparinga Gorge region, southern Adelaide fold belt, South Australia /." Title page, contents and abstract only, 1993. http://web4.library.adelaide.edu.au/theses/09SB/09sbm438.pdf.

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Thesis (B. Sc.(Hons.))--University of Adelaide, Dept. of Geology and Geophysics, 1994.
Four coloured maps in pocket inside back cover. Three plates have overlays. National grid reference (SI 54) 6627(1: 50000). Includes bibliographical references.

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Rolon, Luisa F. "Structural geometry of the Jura-Cretaceous rift of the Middle Magdalena Valley basin--Colombia." Morgantown, W. Va. : [West Virginia University Libraries], 2004. https://etd.wvu.edu/etd/controller.jsp?moduleName=documentdata&jsp%5FetdId=23.

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Thesis (M.S.)--West Virginia University, 2004.
Title from document title page. Document formatted into pages; contains vi, 63 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 29-37).

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Preston, Leiph Alexander. "Simultaneous inversion of 3D velocity structure, hypocenter locations, and reflector geometry in Cascadia /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/6816.

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Mohapatra, Gopal Krishna 1968. "Faulting and basin geometry beneath the Great Salt Lake: implications for basin evolution and cenozoic extension." Diss., The University of Arizona, 1996. http://hdl.handle.net/10150/565551.

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Plumridge, Timothy H. "A geometry-based simulation of the hydration of ions and small molecules." Thesis, University of Strathclyde, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366785.

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Gokce, Semirhan. "A Structural Equation Modeling Study: Factors Related To Mathematics And Geometry Achievement Across Grade Levels." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/3/12606697/index.pdf.

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The factors related to mathematics and geometry achievement were modeled in this study. It was based on the data obtained from the Student Assessment Program carried out by Ministry of National Education. Mathematics achievement tests and student questionnaires of each grade were analyzed by using principal component analysis to obtain different dimensions that are expected to be related with student achievement. Before the principal component analysis, a content based evaluation of the content of the mathematics achievement tests was actualized and the items were grouped as mathematics and geometry. Regarding the student questionnaire socio-economic status, perception of success and interest toward mathematics and science, student-centered activities and teacher-centered activities in the classroom were identified as factors through the principal component analysis. Thereafter, three models were designed and tested by structural equation modeling technique (SEM) using LISREL 8.54. Path analysis with latent variables was used for testing the models. The following results were obtained in the study. In all of the models, socioeconomic status had a positive impact on the mathematics and geometry achievement of the students for all the grade levels examined. Teacher centered activities were found to be positively related with the students&rsquo
success of mathematics and geometry. On the other hand, student centered activities intended to have a negative relation with mathematics and geometry achievement. As the other variables were considered, an increase on the mathematics and geometry scores of the students&rsquo
was observed in all grade levels with the increase in the perception of success and interest toward mathematics and science.

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Dyck, Cynthia Lynn. "Fold geometry and structural history of the Puffy Lake area, Kisseynew gneiss belt, Manitoba, Canada." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq23794.pdf.

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Goshtasbi, Goharizi K. "Model studies of mine excavation stability with special reference to stress field and structural geometry." Thesis, University of Nottingham, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378762.

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Giannoukos, Konstantinos. "Micro-structural analysis of time-variant evolution in pore geometry of cement materials during carbonation." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/37149/.

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The purpose of this project was to gain a fundamental understanding of the carbonation-induced alterations in borehole grouts. This was approached by determining the relationship between the chemical denaturation of the minerals in the evolving pore network and its associated transport properties. These changes resulted from material processing under a range of simulated underground temperatures, pressures and pH. The pore network geometry and transport properties were examined as a function of the degree of structural and mineral alteration. These alterations were then macroscopically related to the depth evolution of the carbonation fronts under elevated temperature and pressure conditions. The microstructure, pore geometry and transport properties were studied experimentally for class G cementitious grout samples immersed in CO2 saturated brine at 60ºC and 120ºC (80 bar) for durations up to 5 months. The evolution of the carbonation depth was captured by means of X-ray computed tomography (XRCT), the compositional changes were detected using scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDXA) and X-ray diffraction (XRD) and finally the pore geometry was revealed using mercury intrusion porosimetry (MIP) and N2-physisorption. Temperature was the most sensitive variable to control the rate of alteration for both microstructure and pore network. Calcium leaching in the samples treated with N2-saturated brine was found to be a thermally dependent process; in fact the activation energy for Ca transport was found to be higher when increasing temperature from 60ºC to 120ºC. At temperatures higher than 60ºC full conversion of portlandite to other forms was justified on the grounds of activation energy and appeared to cause chemical instabilities within the grouts. Those instabilities where aggravated in the case of the carbonated brine. The examined carbonated samples showed two clearly defined areas (inner core and carbonated region) for any duration, that were separated by a clear demarcation line, namely the carbonation front. The time evolution of the carbonation depth was found to follow a power law equation that reflected the rate of diffusion for each temperature. At 60ºC the higher rate of diffusion led to faster local supersaturation conditions in the pores (with respect to Ca2+ and〖 HCO〗_3^-) justifying the growth of aragonite crystals. At 120ºC, the slower rate of diffusion was reflected by the growth of calcite. At 60ºC and 120ºC, both inner and carbonated parts exhibited a sealing stage (up to 1 month) and a dissolution stage (up to 5 and 3 months). The terms ‘sealing’ and ‘dissolution’ referred only for changes in the apparent porosity but in reality these changes were found to reflect the changes of the critical cavity to throat ratio due to different temperature and time. At 60ºC the permeability was proved to be controlled by the critical throats (big values of cavity/ throat ratio) and at 120ºC by the size of the critical cavity (small cavity/ throat ratio). The critical size of the pores and throats at 120ºC close to 12 nm, supported the unrestricted diffusion of calcium towards the outer and hence the faster buffering of the effluent bicarbonates. At 120ºC, the buffering was found to take place at the surface sites of the C-S-H particles and thus from structural Ca2+. At 60ºC the restricted transport of species due to the small critical throats (~4 nm) resulted in the big cavities which were the loci of aragonite crystallization from the free Ca2+. This distinction of ‘diffusion’ at 120ºC and ‘restricted transport’ at 60ºC, was the key point for the better fitting of the time evolution of the carbonation front to the x_C=A∙t^(1/2) at 120ºC. At the inner parts of the CO2 treated samples at 120ºC, in order the throats and cavities to resemble in size, the silicate matrix was suggested to experience simultaneously localized expansion (decreasing the cavity size) and shrinkage (throat enlargement). At 60ºC the preservation of the threshold diameter, the intensified ink-bottle phenomenon and same critical throats close to 3 nm, could have been caused due to: (1) the retarded pozzolanic reactions at 60ºC that would have caused the throats to be mechanically stable due to the microsilica particles and, (2) the small activation energy for the C-S-H particles to re-organize their structures and to align them leading to silicate condensation and polymerization. The plethora of existing oilwells sealed with ordinary Portland cements globally, dictates that the permeability of the entire well to CO2 fluids will rely on the diffusion among the pores of the C-S-H structures. The permeability values from this study (ranging from 70 μD to 0.1 μD) were found to allow for the efficient geological storage for CO2 across the entire range of temperatures studied but with different mechanisms of diffusion. The major significance of the present thesis was that it provided a better understanding of the relationship between the cement microstructure with its pore network parameters, a relationship that ultimately determined the permeability and extent of carbonation in the long term. In other words the aim of the thesis was fulfilled giving a more comprehensive image during carbonation of a class G oil well cement grout in a realistic scenario of geological storage of CO2, with temperature and time to be the only variables. The implications of the studied temperatures (60ºC and 120ºC) and durations (1, 3 and 5 months) in real CO2 injection wells, could provide better assessment of legacy injection wells (containing aged cement grouts) and more efficient design of new CO2 injection wells.

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Al, Marza Raad. "Effect of the interface geometry on the structural integrity of the ceramic crown-tooth complex." Thesis, University of Sheffield, 2015. http://etheses.whiterose.ac.uk/8718/.

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The effect of the interface lute on the structural integrity of the tooth adhesively restored with an all-ceramic crown remains is an unknown parameter especially in relation to the interface geometry (thickness and uniformity). Traditionally, the structural integrity of a restored tooth system (tooth-lute-crown) is tested by laboratory based mechanical testing. However, a more sophisticated FEA computer modelling seems to provide a non-destructive way of understanding the structural integrity of the system, which may complement mechanical testing.

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Edgar, Russell. "Effects of Strand Geometry on Selected Properties of Long-Stand Structural Composite Lumber Made from Northeastern Hardwoods." Fogler Library, University of Maine, 2003. http://www.library.umaine.edu/theses/pdf/EdgarRA2003.pdf.

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Bradway, Michael David. "Stratigraphy and structural geometry at the leading edge of the Montana Thrust Belt, east of Sun River Canyon, Lewis and Clark and Teton Counties, Montana." CONNECT TO THIS TITLE ONLINE, 2007. http://etd.lib.umt.edu/theses/available/etd-05072007-163806/.

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Song, Mingkui. "A structural skeleton based shape indexing approach for vector images." Diss., Online access via UMI:, 2009.

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Glasgo, Victor. "Some Structural Results for Convex Bodies: Gravitational Illumination Bodies and Stability of Floating Bodies." Case Western Reserve University School of Graduate Studies / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case1586291378035804.

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Fanelli, Andrea. "Two structural aspects in birational geometry : geography of Mori fibre spaces and Matsusaka's theorem for surfaces in positive characteristic." Thesis, Imperial College London, 2015. http://hdl.handle.net/10044/1/26285.

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The aim of this thesis is to investigate two questions which naturally arise in the context of the classification of algebraic varieties. The first project concerns the structure of Mori fibre spaces: these objects naturally appear in the birational classification of higher dimensional varieties and the minimal model program. We ask which Fano varieties can appear as a fibre of a Mori fibre space and introduce the notion of fibre-likeness to study this property. This turns out to be a rather restrictive condition: in order to detect this property, we obtain two criteria (one sufficient and one necessary), which turn into a characterisation in the rigid case. Many applications are discussed and the basis for the classification of fibre-like Fano varieties is presented. In the second part of the thesis, an effective version of Matsusaka's theorem for arbitrary smooth algebraic surfaces in positive characteristic is provided: this gives an effective bound on the multiple which makes an ample line bundle D very ample. A careful study of pathological surfaces is presented here in order to bypass the classical cohomological approach. As a consequence, we obtain a Kawamata-Viehweg-type vanishing theorem for arbitrary smooth algebraic surfaces in positive characteristic.

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Mesnil, Romain. "Explorations structurelles de domaines de formes constructibles pour l’architecture non-standard." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1151/document.

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Les dernières décennies ont vu l’émergence de formes architecturales non standard. Les concepteurs se retrouvent généralement démunis face à la complexité géométrique de ces objets, dont la fabrication rime souvent avec complication. De plus, les outils utilisés dissocient forme et fonctionnement structurel,ce qui complexifie le processus de décision pour ingénieurs et architectes. Ce mémoire prend un point de vue fondé sur la notion d’invariance par transformation géométrique et étudie plusieurs strategies de génération de formes naturellement constructibles pour remédier à ces manques. Trois contraintes constructives ont été identifiées et correspondent à trois contributions indépendantes de cette thèse.La répétition des noeuds d’assemblage est étudiée via les transformations par maillages parallèles. Ces dernières sont utilisées pour créer une généralisation des surfaces de révolution. On retrouve par là un paramétrage particulier des surfaces moulures de Monge avec une grande répétition d’éléments, et notamment de noeuds d’assemblage.Les réseaux de cyclides sont ensuite utilisés pour dessiner des formes parametrées par leurs lignes de courbures. Cela permet la couverture par panneaux plans ainsi que l’offset des éléments structurels sans excentricité. L’apport de cette thèse est l’implémentation de plusieurs améliorations, notamment l’introduction de plis à double courbure, un algorithme permettant de généraliser les réseaux de cyclides à des topologies quelconques, et la génération de surfaces généralisant les surfaces canal à partir de deux courbes rail et une courbe profil.Finalement, une méthode innovante inspirée de la géométrie descriptive permettant la génération de formes courbes couvertes par des quadrilatères plans est proposée. La méthode, baptisée méthode marionnette, réduit ce problème à un système linéaire, ce qui permet une manipulation de ces forms constructibles en temps réel. Une étude comparative montre que cette technique peut être utilisée pour paramétrer des problèmes d’optimisation de forme de coques sans perte de performance par rapport aux paramétrages utilisés de façon classique. L’intégration des contraintes de fabrication dans le processus d’optimisation structurelle ouvre de nouvelles possibilités d’applications, comme des résilles gauches et des coques plissées. La pertinence de ces nouvelles solutions est démontrée par de multiples études de cas
The last decades have seen the emergence of non-standard architectural shapes. Designers find often themselves helpless with the geometrical complexity of these objects. Furthermore, the available tools dissociate shape and structural behaviour, which adds another complication. This dissertation takes the point of view based on invariance under geometrical transformations, and studies several strategies for fabrication-aware shape modelling. Three technological constraints have been identified and correspond to three independent contributions of this thesis.The repetition of nodes is studied via transformations by parallelism. They are used to generalise surfaces of revolution. A special parametrisation of moulding surfaces is found with this method. The resulting structure has a high node congruence.Cyclidic nets are then used to model shapes parametrised by their lines of curvature. This guarantees meshing by planar panels and torsion-free beam layout. The contribution of this dissertation is the implementation of several improvements, like doubly-curved creases, a hole-filling strategy that allows the extension of cyclidic nets to complex topologies, and the generation of a generalisation of canal surfaces from two rail curves and one profile curves.Finally, an innovative method inspired by descriptive geometry is proposed to generate doubly-curved shapes covered with planar facets. The method, called marionette technique, reduces the problem to a linear problem, which can be solved in real-time. A comparative study shows that this technique can be used to parametrise shape optimisation of shell structures without loss of performance compared to usual modelling technique. The handling of fabrication constraints in shape optimisation opens new possibilities for its practical application, like gridshells or plated shell structures. The relevance of those solutions is demonstrated through multiple case-studies

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Descamps, Benoît. "Optimal shaping of lightweight structures." Doctoral thesis, Universite Libre de Bruxelles, 2013. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209362.

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Designing structures for lightness is an intelligent and responsible way for engineers and architects to conceive structural systems. Lightweight structures are able to bridge wide spans with a least amount of material. However, the quest for lightness remains an utopia without the driving constraints that give sense to contemporary structural design.

Previously proposed computational methods for designing lightweight structures focused either on finding an equilibrium shape, or are restricted to fairly small design applications. In this work, we aim to develop a general, robust, and easy-to-use method that can handle many design parameters efficiently. These considerations have led to truss layout optimization, whose goal is to find the best material distribution within a given design domain discretized by a grid of nodal points and connected by tentative bars.

This general approach is well established for topology optimization where structural component sizes and system connectivity are simultaneously optimized. The range of applications covers limit analysis and identification of failure mechanisms in soils and masonries. However, to fully realize the potential of truss layout optimization for the design of lightweight structures, the consideration of geometrical variables is necessary.

The resulting truss geometry and topology optimization problem raises several fundamental and computational challenges. Our strategy to address the problem combines mathematical programming and structural mechanics: the structural properties of the optimal solution are used for devising the novel formulation. To avoid singularities arising in optimal configurations, the present approach disaggregates the equilibrium equations and fully integrates their basic elements within the optimization formulation. The resulting tool incorporates elastic and plastic design, stress and displacements constraints, as well as self-weight and multiple loading.

Besides, the inherent slenderness of lightweight structures requires the study of stability issues. As a remedy, we develop a conceptually simple but efficient method to include local and nodal stability constraints in the formulation. Several numerical examples illustrate the impact of stability considerations on the optimal design.

Finally, the investigation on realistic design problems confirms the practical applicability of the proposed method. It is shown how we can generate a range of optimal designs by varying design settings. In that regard, the computational design method mostly requires the designer a good knowledge of structural design to provide the initial guess.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished

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Osborne, Daniel L. "An analysis of developmental plasticity in structural geometry at the proximal femur in adolescent females living in the United States." [Bloomington] : Indiana University, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3264308.

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Thesis (Ph.D.)--Indiana University, Dept. of Anthropology, 2007.
Source: Dissertation Abstracts International, Volume: 68-05, Section: A, page: 2031. Advisers: Della Collins Cook; David Burr. Title from dissertation home page (viewed Jan. 9, 2008).

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Borenstein, Evan. "Additive stucture, rich lines, and exponential set-expansion." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29664.

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Thesis (Ph.D)--Mathematics, Georgia Institute of Technology, 2009.
Committee Chair: Croot, Ernie; Committee Member: Costello, Kevin; Committee Member: Lyall, Neil; Committee Member: Tetali, Prasad; Committee Member: Yu, XingXing. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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Khoo, Benjamin Cheng Choon. "Clinical and phantom-based studies of the validity and value of quantitative radiological hip structural analysis." University of Western Australia. School of Surgery and Pathology, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0189.

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[Truncated abstract] Areal bone mineral density (BMD) is measured routinely in the clinic by a quantitative radiological technique, dual-energy X-ray absorptiometry (DXA). BMD is used widely to assess non-invasively but indirectly the mechanical fragility of bone and consequently is able to predict fracture risk. While BMD correlates well with in vitro measurements of bone strength it does not directly measure a mechanical property; half of incident minimally traumatic fractures in women occur with BMD values above the World Health Organisation defined threshold for osteoporosis. This arises partly because the mechanical strength of bone is dependent on its structural geometry and material strength as well as bone mineral mass. Essentially, bones fracture when load stresses exceed the mechanical capacity of the material to withstand them. The structural geometry (i.e., the amount of bone tissue and its complex three-dimensional arrangement within the macroscopic bone envelope) defines the stresses produced by a given load, while the intrinsic load capacity of the material is defined by the composition and microstructure of the bone tissue itself. Hip structural analysis (HSA) is a technique that elucidates the structural geometric component of bone strength; essentially combining information available from conventional DXA images of the proximal femur with a biomechanical beam model based on the stresses arising in a combination of pure bending and axial compression. A version of HSA has recently been released commercially, and has obtained US Food and Drug Administration approval for its clinical application. ... Given the acknowledged limitations of the HSA method when applied to 2-D projection images, a 3-D approach to structural geometry, using imaging modalities such as pQCT and QCT or a recently introduced version of DXA that mimics QCT, is indicated for the future. With that in mind and the possibility of the anthropometric phantom being adopted for future accuracy and precision assessments, improvements in the design of this phantom are recommended. Studies to better understand and verify Contents v the relevance of the 'local buckling' phenomenon as a structural geometric factor in the genesis of macro-fractures are also recommended. In summary, it is essential that superior (compared to BMD) non-invasively determined clinical predictors of bone fragility leading to fracture be investigated. Structural geometric variables are potential candidates. This has led to consideration of; (i) the need to progress beyond BMD for a more sensitive and specific bone strength measurement; (ii) theoretical advantages of structural geometry over BMD; (iii) limitations of the current HSA technique based on DXA, including those introduced by its restrictive assumptions; (iv) the value of HSA in longitudinal studies, exemplified by the 'normal' but rapid skeletal changes seen in human lactation, with possible implications for an analogous study of the menopause; and (v) an investigation, using a custom-designed anthropometric phantom, of the adaptation of HSA to certain emerging imaging modalities and methods able to resolve bone structural geometry in three dimensions.

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Pinheiro, Douglas Garrido. "ESTUDO DO COMPORTAMENTO MECÂNICO DE BLOCOS CERÂMICOS COM DIFERENTES LARGURAS." Universidade Federal de Santa Maria, 2009. http://repositorio.ufsm.br/handle/1/7742.

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The main goal of this project is comparing the performance of structural ceramic blocks with 11,5 (Block A) e 14 (Block B) centimeters thickness, through tests with blocks, prisms and small walls using two types of mortar, ii and iii, determined by the British Norm (BS-5628) developed in laboratory. The experimental program includes simple axial units compression tests, prisms of three overlapping rows and wallettes of two blocks by four height rows. During the prisms and wallettes tests, their strains were measure, and subsequently the elasticity modulus was obtained. From the results, it was concluded that the 11,5 centimeters thickness block (Block A) presented the capacity to absorve the strain of equal value as the tradicional block, and may be used with safety. Analyzing the results of the tests it was possible to verify different values near to the compression strength value in the test specimens using the two types of blocks, establishing difference between prisms and wallettes, with the same type of mortar. It was carried out the statistical analysis to check the difference between the blocks, where it was observed the equality between the blocks with average compression strength and the prisms with two types of mortar, however in the wallettes tests it was observed difference between the average strength with the two types of blocks.
Este trabalho apresenta como objetivo principal avaliar o desempenho de blocos cerâmicos estruturais de 11,5 (Bloco A) e 14 (Bloco B) centímetros de largura, através de ensaios de blocos, prismas e pequenas paredes, utilizando dois traços de argamassa designados pela Norma Britânica, confeccionados em laboratório. O programa experimental compreendeu ensaios de compressão axial simples das unidades, prismas de três fiadas sobrepostas e pequenas paredes de dois blocos por quatro fiadas de altura. Durante os ensaios de prismas e pequenas paredes foram medidas suas deformações e, posteriormente, obtidos os módulos de elasticidade dos elementos. Com base na análise dos resultados, é possível concluir que o bloco com 11,5 centímetros de largura apresenta capacidade de absorver esforços equivalente ao bloco tradicional, podendo ser empregado com segurança. Foi possível verificar valores próximos de resistência à compressão para os corposde- prova ensaiados utilizando os dois tipos de blocos, estabelecendo comparações entre prismas e pequenas paredes com um mesmo traço de argamassa. Foi realizada a análise estatística do experimento, para verificar a comparação entre os dois blocos, onde foi observada a igualdade entre as resistências à compressão média para os ensaios de blocos e prismas com os dois tipos de argamassa, no entanto nos ensaios com pequenas paredes foi observada diferença entre as resistências médias obtidas com os dois tipos de blocos.

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Yang, Zhengxiong [Verfasser], Ernst [Akademischer Betreuer] Rank, Alexander [Akademischer Betreuer] Düster, and Jamshid [Akademischer Betreuer] Parvizian. "The Finite Cell Method for Geometry-Based Structural Simulation / Zhengxiong Yang. Gutachter: Ernst Rank ; Alexander Düster ; Jamshid Parvizian. Betreuer: Ernst Rank." München : Universitätsbibliothek der TU München, 2011. http://d-nb.info/1014330602/34.

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Abdelhamid, Hazen Fahmy. "Incorporation of sweep in a transonic fan design using a 3D blade-row geometry package intended for aero-structural-manufacturing optimization." Diss., Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1997. http://handle.dtic.mil/100.2/ADA341590.

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Dissertation (Ph.D. in Aeronautical Engineering) Naval Postgraduate School, September 1997.
"September 1997." Dissertation supervisor(s): Raymond P. Shreeve. Includes bibliographical references (p. 107-108). Also available online.

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Molinaro, Matteo. "Geometry and kinematics of the SE Zagros Mountains (Iran) : structural geology and geophysical modelling in a young collisional fold-thrust belt." Paris 11, 2004. http://www.theses.fr/2004PA112177.

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L'objectif de cette thèse est l'étude de la structure et la cinématique du Zagros oriental (Iran) et de la zone de transition avec le prisme du Makran appelée syntaxe de Bandar Abbas. Une étude structurale de terrain a permis de mettre en évidence le contrôle exercé par la stratigraphie mécanique - et donc les conditions paleogéographiques - sur le style structural d'un côté à l'autre de la syntaxe. La restauration de la première coupe équilibrée à travers le sud-est de la ceinture du Zagros permet de montrer que le Zagros plissé a subi deux phases téctoniques majeures, une première impliquant uniquement la couverture suivie par une deuxième impliquant le socle. Le raccourcissement accommodé dans la section depuis le Miocène moyen est d'au moins 45 km. La présence d'une puissante série évaporitique à la base de la couverture a favorisé le developpement de grands plis de décollement. L'analyse d'exemples de terrain dans la région d'étude ainsi que de profils sismiques dans le Zagros Central permet de discuter la cinématique de ces plis ainsi que les facteurs contrôlant leur style, notamment la mobilité du sel, l'existence de multiples décollements et le rôle tardif des failles de socle. Enfin, une modélisation géophysique de la structure lithosphérique du Zagros permet de discuter les facteurs fondamentaux qui ont guidé l'évolution récente de l'orogène. On met en évidence une amincissement lithosphérique qui pourrait être lié à un détachement récent du slab plongeant. Ce processus pourrait expliquer la transition récente d'une tectonique de couverture à une tectonique de socle
This thesis focuses on the structure and kinematics of the south-eastern Zagros Mountains (Iran) and the transitional structures with the adjacent Makran accretionary prism, known as the Bandar Abbas syntaxis. The structural style, as evidenced by a field-based structural study, is strongly controlled by changing mechanical stratigraphy and therefore paleogeographic conditions from one side to the other of the syntaxis. Restoration of the first complete balanced cross-section through the south-eastern Zagros fold-thrust belt shows that the external part of the orogen (a) underwent two main phases of deformation, i. E. A thin-skinned phase of deformation followed and partly overprinted by a thick-skinned phase, and (b) absorbed at least 45 km of shortening since middle Miocene times. The presence of an exceptionally thick layer of salt at the base of the cover allowed the development of huge detachment anticlines. Field examples from our study area and seismic profiles from Central Zagros allow us to discuss the still poorly understood kinematics of these folds as well as examine the various factors controlling the style of folding, essentially salt mobility, multiple decollement levels and late basement faulting. Finally, geophysical modelling of the deep lithospheric structure of Zagros brings new insight on the fundamental factors controlling the recent orogenic kinematics. In particular, a previously undocumented thinning of the lithosphere beneath Zagros could be attributed to recent slab break-off and is thought to have controlled the recent switch from thin-skinned to thick-skinned tectonics

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Spyrou, Evangelos. "The effect of shell geometry on the impact attenuating capabilities of ice hockey helmets relative to liner structural characteristics and impact conditions." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ29578.pdf.

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Mildon, Z. K. "The link between earthquakes and structural geology : the role of elapsed time, 3D geometry and stress transfer in the central Apennines, Italy." Thesis, University College London (University of London), 2017. http://discovery.ucl.ac.uk/10039494/.

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The role of fault geometry, Coulomb stress and elapsed time is investigated herein to determine whether earthquakes are clustered or not in the central Apennines, Italy. Two earthquake sequences are analysed to determine the relative importance of Coulomb stress transfer and elapsed time. The importance of fault geometry when modelling the Coulomb stress transfer is demonstrated. The earthquake sequences of interest can be partially explained by a combination of Coulomb stress transfer and elapsed time, thus demonstrating that earthquakes in the central Apennines are non-stochastic in nature. Considering the variations in fault geometry over short (hundreds of metres) length scale has been used to demonstrate that the surface bedrock fault scarps are active. Over longer scales (kilometres) the geometry of the faults is shown to affect the pattern of Coulomb stress transferred during earthquakes. A novel methodology outlined in this thesis is used to model Coulomb stress changes throughout the historical record onto faults with strike-variable geometry. It is shown that the Coulomb stress transfer is likely to have played a role in two earthquake se- quences of interest, the 1703 - 1706 A.D. and 2016 - 2017 A.D. sequences. However Coulomb stress transfer cannot fully explain these sequences. The elapsed time on faults of interest to these sequences is considered, and it is shown that faults with longer elapsed time rupture preferentially over faults with shorter elapsed time in both se- quences. When considered together, fault geometry, Coulomb stress and elapsed time considered together can explain the progression of the 2016 - 2017 A.D. earthquake sequence. The 1703 - 1706 A.D. sequence can be explained in a similar manner, how- ever the results are less conclusive due to a lack of elapsed time data. Elapsed time cannot be considered alone, without information about the mean recurrence intervals on faults of interest. The results presented herein have implications for estimations of seismic hazard.

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Yassaghi, Ali. "Geometry, kinematics, microstructure, strain analysis, and P-T conditions of the shear zones and associated ductile thrusts in the southern Mt. Lofty Ranges/Adelaide Hills area, South Australia /." Title page, contents and abstract only, 1998. http://web4.library.adelaide.edu.au/theses/09PH/09phy29.pdf.

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Angleby, Linda. "Structural and electronic properties of bare and organosilane-functionalized ZnO nanopaticles." Thesis, Linköping University, Linköping University, Linköping University, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-58691.

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A systematic study of trends in band gap and lattice energies for bare zinc oxide nanoparticles were performed by means of quantum chemical density functional theory (DFT) calculations and density of states (DOS) calculations. The geometry of the optimized structures and the appearance of their frontier orbitals were also studied. The particles studied varied in sizes from (ZnO)₆ up to (ZnO)₁₉₂.The functionalization of bare and hydroxylated ZnO surfaces with MPTMS was studied with emphasis on the adsorption energies for adsorption to different surfaces and the effects on the band gap for such adsorptions.

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Springer, Adam. "Constraining Basin Geometry and Fault Kinematics on the Santo Tomás Segment of the Agua Blanca Fault Through a Combined Geophysical and Structural Study." Scholar Commons, 2010. https://scholarcommons.usf.edu/etd/1779.

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The Agua Blanca fault is a major transverse structure of northern Baja California, extending more than 120km east from the Punta Banda ridge near the city of Ensenada to the San Matais Pass in central Baja. Through much of its eastern extent slip on this fault appears to be pure strike slip, however, at the Valle de Santo Tomás the fault makes a ~25°; change in orientation, which coincides with the formation of extensional basins on the fault. Recent evidence of the independent movement of the Baja Micro-plate relative to a stable Southern California Black leads to several possible hypotheses to explain this including: 1)That basins are localized structures, the result of a series of right steps or bends along the dextral Agua Blanca fault. 2)Basins are transtensional, possibly as a result of complexities associated with the northern boundary of the Baja Micro-plate . To test between these hypotheses it was necessary to constrain the fault kinematics on both basin bounding and in-basin faults, well as the basin geometry. This was accomplished through combined structural and geophysical surveys. Data collected suggest that the majority of dip-slip is confined to the Santo Tomás fault bounding the basin to the south, while the Agua Blanca fault bounding the basin to the north is primarily strike slip. This orientation typical in transtensional basins, suggesting that although Valle de Santo Tomás formed at a step over it is not a pull apart basin. Possible explanations for transtension in this area come from the orientation of the Agua Blanca fault in relation to the Baja Micro-plate. Where the fault is close to aligned with the relative motion of the plate there is little transtension, such as in Valle de Agua Blanca, however, where the fault makes a 25° change in orientation and becomes more oblique the motion of the Baja Micro-plate transtension is present.

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Dissertations / Theses on the topic 'Structural geometry'

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