ABSTRACT SIMULATION OF SURFACE WAVES GENERATED BY A RAPID RISE OF A BLOCK AT THE SEA BOTTOM SENOL, Nalan M.Sc., Department of Civil Engineering, Supervisor: Assoc. Prof. Dr. ismail AYDIN July 2005, 74 Pages A mathematical model is developed for investigating time dependent surface deformations of a hydrostatic water volume, when it is subjected to a sudden partial rise of the sea bottom. In the model, 2-dimensional, compressible, and viscous Navier-Stokes equations are solved by Marker and Cell (MAC) method. Variable mesh size in both horizontal and vertical directions with a staggered grid arrangement is used. Limited compressibility model is utilized for pressure. Various computational tests are done for the selection of computational parameters of the model. It is found that the amplitude of surface waves generated by vertical displacements of the sea bottom depends on size and speed of bottom displacements.

For a bridge engineer, it is very important to estimate the maximum scour depth around the piers as accurately as possible, in order to design the footing safely. Many experimental studies have been performed by several investigators until now, in order to obtain information about scouring mechanism. The aim of this experimental study is to examine the effect of inclination of the dual bridge piers on scour depth. The experiments have been conducted with dual pier models under clear-water conditions, for various uniform flow depths. Scour depths had been measured at four different points around the piers / namely upstream and downstream faces of both piers. Dimensional and non-dimensional scour curves have been developed and presented to show the temporal variation of scour depth. The depths of local scour around inclined piers have been observed to be smaller than the scour depths around vertical piers.

Laplace transform step-response functions are presented for one dimensional transient flow in fractured semi-infinite &amp / finite aquifers. Unsteady flow in the aquifer resulting from a constant discharge pumped from the stream is considered. Flow is one-dimensional, perpendicular to the stream in the confined aquifers. The stream is assumed to penetrate the full thickness of the aquifer. The aquifers may be semi-infinite or finite in width. The Laplace domain solutions are numerically inverted to the real-time domain with the Stehfest (1970) algorithm. During the course of the thesis a simple computer code is written to handle the algorithm and the code is verified by applying it to the one-dimensional transient flow in a semi-infinite homogeneous aquifer problem which can be solved analytically to crosscheck with the numerical results.

Water distribution networks are being designed by traditional methods based on rules-of-thumb and personal experience of the designer. However, since there is no unique solution to any network design, namely there are various combinations of pipes, pumps, tanks all of which satisfy the same pressure and velocity restrictions, it is most probable that the design performed by traditional techniques is not the optimum one. This study deals how an optimization technique can be a useful tool for a designer during the design to find a solution. The method used within the study is the partial enumeration technique developed by Gessler. The technique is applied by a commercially available software, i.e. WADISO SA. The study is focused on discrepancies between a network designed by traditional techniques and the same network designed by partial enumeration method. Attention is given to steps of enumeration, which are basically grouping of pipes, candidate pipe size and price function assignments, to demonstrate that the designers can control all the phases of optimization process. In this respect, special attention is given to price functions to show the effect of them on the result. The study also revealed that the cost of fitting materials cannot be included in the price function although it may have significant effect in a system composed of closely located junctions. The results obtained from this study are useful to show that although optimization methods do not provide a definite solution / partial enumeration method can assist designers to select the optimum system combination.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 6 uppsatser.

Diss. (sammanfattning) Umeå : Univ., 2006. / Härtill 5 uppsatser.

Thesis (Ph. D.)--Miami University, Dept. of Geology, 2007. / Title from second page of PDF document. Includes bibliographical references.

Wave-structure interactions play an important role on the design and maintenance of coastal and offshore constructions. Computational Fluid Dynamics (CFD) is a convenient tool for analyzing wave-structure interactions in costal and offshore engineering. The potential model and the viscous model are traditional mathematical models for wave-structure interactions, which have disadvantages in computational robustness, when they are applied individually. Therefore, recently, more and more multi-model methods are used for coupling the viscous model and the potential model together. So far, in the existing multi-model methods, the surface-piercing structure only exists in the viscous domain so that the viscous domain should be large enough. In order to improve the computational efficiency, some multi-model methods are developed, where the structure is considered in both viscous domain and Euler domain. Firstly, by function-decomposition method, an Euler-viscous hybrid model is proposed. Comparing with the other function-decomposition hybrid models, a surface-piercing structure exists in both a large Euler domain and a small viscous domain. By this, the reflection, diffraction, and radiation waves from the structure can be considered in both two computational domains. Therefore, the computational efficiency can be enhanced remarkably. To couple the Euler model and the viscous model, complementary RANS equations are deduced, with complementary turbulence models. Corresponding boundary conditions are also developed for coupling. A relaxed scheme is proposed for damping the viscous effects and keeping free surface consistent. For wave interactions with moving structures, the transition of total forces acting on the structure from the viscous domain to the Euler domain is used to guarantee the same motion of structures in two domains. Secondly, the function-decomposition Euler-viscous hybrid model is extended by domain-decomposition method. Then, function-decomposition method and domain-decomposition method are coupled together. The wave generation and propagation is solved in a potential domain. By this, the computational efficiency for wave-structure interactions in a large real wave tank can be improved. Computational robustness of Euler-viscous hybrid model for surface-piercing wave-structure interactions are studied by some cases. It is found that the size of the viscous domain, the length of transition zone, and mesh resolution can affect computational precision. Computational efficiency is mainly affected by the size of the viscous domain. For extended Euler-viscous hybrid model, the distance before reaching the inlet boundary of the Euler domain plays a crucial role on computational accuracy and efficiency. Validations are done by comparing numerical results based on hybrid models, conventional RANS model and experimental results. It is shown that hybrid models own the same computational accuracy as the conventional RANS model. Furthermore, the computational accuracy can be improved remarkably. In some cases, more than 85% CPU time can be saved. The hybrid models are applied to simulate wave interactions with a structure subjected to seabed effects. By comparing with numerical simulations based on the conventional RANS model, it is indicated that hybrid models can be also used on complex computational domain. Some properties of wave interactions with a floating structure subjected to a submerged structure are found by numerical simulations.

Sunflower (Helianthus annuus) consists of high levels of polyunsaturated fatty acids, making its oil susceptible to oxidation. Tocopherols can retard or prevented oxidation. The aim of this study is to determine the phenotypic tocopherol (vitamin E) composition and genetic diversity of the biosynthetic pathway genes. Seeds were characterized for fatty acid and tocopherol content. A positive correlation was found between oleic acid, γ (r =0.17) and δ (r =0.23) tocopherol but none between linoleic acid and all four tocopherol derivatives. Vitamin E gene homologues were identified and a concomitant pathway constructed, with genes of interest sequenced to determine their genetic variation. A sunflower gene database was developed for these genes and used to obtain 489 SNPs and 145 indels from the accessions evaluated. Only 139 of these SNPs were located in the exon regions of the gene candidates. These exon-based SNPs may influence tocopherol flow through possible enzyme structural modifications / School of Agriculture and Life Sciences / M. Sc. (Life Sciences)

A reabilitação dos pacientes com fissura de lábio e palato teve significativa evolução nas últimas décadas, sendo o desenvolvimento do enxerto ósseo alveolar muito importante para este avanço. É um procedimento que requer atenção rigorosa aos detalhes, por esta razão os exames de imagem são de grande auxílio. As Tomografias Computadorizadas enriqueceram os métodos de diagnóstico, despertando o interesse nos estudos desta modalidade de exame dentro da abordagem terapêutica da fissura labiopalatina. Este trabalho tem por objetivo desenvolver uma metodologia para avaliar o volume da fenda alvelar, por meio de Tomografia Computadorizada por Feixe Cônico. Utilizou-se o Software Open Source OsiriXTM DICOM Viewer Apple Inc, Versão 3.7.1 32 bits, um software de domínio público e que pode ser baixado gratuitamente na internet. Este software permite a visualização e manipulação de arquivos de tomografia computadorizada, desde de que os mesmos sejam salvos no formato DICOM, oferecendo possibilidade de mensuração tanto de medidas lineares, como de cálculo de área e de volume, sempre em proporções reais (1:1). A amostra foi constituída pelas imagens tomográficas de 30 pacientes, sendo 24 portadores de fissuras unilaterais e 6 de bilaterais, com idade média de 09 anos e 09 meses, sendo 19 do gênero masculino e 11 do feminino. Após a importação dos arquivos, foram utilizadas ferramentas do software OsiriXTM por 2 examinadores, em tempos distintos, para se proceder à mensuração do volume da fenda alveolar nos cortes axiais, a qual foi delimitada por meio da demarcação de pontos e limites pré-determinados. Foi realizada a análise pelo Teste da Estatística Alfa de Cronbach, que comprovou o elevado grau de reprodutibilidade e confiabilidade do método proposto (p<0,001). O volume médio encontrado foi de 0,92 ± 0,31 cm3, sendo que em relação aos tipos de fenda observou-se que as fissuras unilaterais apresentaram maior volume do que as bilaterais (p=0,019). Não houve diferenças quanto ao gênero, faixa etária e lado da fissura. Concluiu-se que o software OsiriXTM é eficiente em mensurar o volume da fenda alveolar; o método proposto pode ser reproduzido e o volume médio da fenda alveolar das fissuras unilaterais é maior que o das bilaterais. / Rehabilitation of patients with cleft lip and palate has evolved significantly in recent decades, due to development of the alveolar bone graft procedures. It is a procedure that requires strict attention to detail, and for this reason imaging exams are of great help. Computerized Tomography has enriched the diagnostic methods, arousing interest in studies of this method of examination in the therapeutic treatment of cleft lip and palate. This study aims to develop a methodology to assess the volume of the alveolar cleft, using Cone Beam Computerized Tomography. The 32-bit OsiriX® DICOM Viewer (Apple, Inc., version 3.7.1) open source softtware, a public domain program which can be downloaded for free from the Internet, was used. This software enables the visualization and manipulation of Computerized Tomography files as long as they are saved in the DICOM format, offering possibilities both for making linear measurements and also for calculating area and volume, always in real proportions (1:1). The sample was composed of tomographic images of 30 patients: 24 with unilateral and 6 with bilateral cleft , with average age of 9 years and 9 months, 19 male and 11 female. After importing the files, 2 examiners used tools from the OsiriXTM software, at different times, to measure the volume of the alveolar cleft lip and palate along the axial cuts, which was delimited using demarcation points and predetermined limits. Statistical analysis was performed using Cronbachs Alpha test, which demonstrated the high degree of reproducibility and reliability of the proposed method (p<0,001). The mean volume found was 0.92 ± 0.31 cm3 and, in relation to the type of cleft observed, the unilateral clefts presented larger volume than the bilaterals (p=0,019). There were no differences regarding gender, age range, and side of the cleft. It was concluded that the OsiriXTM software is efficient for measuring the volume of alveolar cleft; that the proposed method can be reproduced; and, that the mean volume of the alveolar unilateral cleft is greater than bilateral clefts.