The mean quadratic elongation, < A >, is used to measure the distortions of close packed arrays of anions in crystals. It is also used to trace how such distortions vary with temperature (T) and pressure (P). A calculation of < ..\ > for arrays of anions in materials that adopt the rutile and olivine structure-types shows that the arrays exhibit increased distortions with increasing P whereas those in materials that adopt the dolomite structure-type exhibit a decrease in distortion. On the other hand, the close packed arrays in the dolomite and calcite structure-types become more distorted with increasing T. The array of oxide anions in rutile show an increased distortion while those in stishovite show a decreased distortion with increasing T. An analysis of apparent bulk moduli and linear thermal expansion coefficients calculated for the constituent polyhedra shows that the distortion of a material with a close packed structure is governed by its unoccupied as well as its occupied polyhedra. It also indicates that the rearrangement of the anions in such materials induced by an increase in P is governed by the apparent bulk moduli of its constituent polyhedra rather than by a tendency of the anions to adopt a more perfect close packed array. / Master of Science

Recent developments in mixed integer programming have highlighted the need for multi-row cuts. To this day, the performance of such cuts has typically fallen short of the single-row Gomory mixed integer cut. This disparity between the theoretical need and the practical shortcomings of multi-row cuts motivates the study of both the mixed integer cut and multi-row cuts. In this thesis, we build on the theoretical foundations of the mixed integer cut and develop techniques to derive multi-row cuts. The first chapter introduces the mixed integer programming problem. In this chapter, we review the terminology and cover some basic results that find application throughout this thesis. Furthermore, we describe the practical solution of mixed integer programs, and in particular, we discuss the role of cutting planes and our contributions to this theory. In Chapter 2, we investigate the Gomory mixed integer cut from the perspective of group polyhedra. In this setting, the mixed integer cut appears as a facet of the master cyclic group polyhedron. Our chief contribution is a characterization of the adjacent facets and the extreme points of the mixed integer cut. This provides insight into the families of cuts that may work well in conjunction with the mixed integer cut. We further provide extensions of these results under mappings between group polyhedra. For the remainder of this thesis we explore a framework for deriving multi-row cuts. For this purpose, we favor the method of superadditive lifting. This technique is largely driven by our ability to construct superadditive under-approximations of a special value function known as the lifting function. We devote our effort to precisely this task. Chapter 3 reviews the theory behind superadditive lifting and returns to the classical problem of lifted flow cover inequalities. For this specific example, the lifting function we wish to approximate is quite complicated. We overcome this difficulty by adopting an indirect method for proving the validity of a superadditive approximation. Finally, we adapt the idea to high-dimensional lifting problems, where evaluating the exact lifting function often poses an immense challenge. Thus we open entirely unexplored problems to the powerful technique of lifting. Next, in Chapter 4, we consider the computational aspects of constructing strong superadditive approximations. Our primary contribution is a finite algorithm that constructs non-dominated superadditive approximations. This can be used to build superadditive approximations on-the-fly to strengthen cuts derived during computation. Alternately, it can be used offline to guide the search for strong superadditive approximations through numerical examples. We follow up in Chapter 5 by applying the ideas of Chapters 3 and 4 to high-dimensional lifting problems. By working out explicit examples, we are able to identify non-dominated superadditive approximations for high-dimensional lifting functions. These approximations strengthen existing families of cuts obtained from single-row relaxations. Lastly, we show via the stable set problem how the derivation of the lifting function and its superadditive approximation can be entirely embedded in the computation of cuts. Finally, we conclude by identifying future avenues of research that arise as natural extensions of the work in this thesis.

Made available in DSpace on 2017-07-10T14:17:03Z (GMT). No. of bitstreams: 1 sostenez.pdf: 5444547 bytes, checksum: 0e57c73e9d81ba62bd8cce82698d43f6 (MD5) Previous issue date: 2013-10-17 / Bombyx mori nucleopolyhedrovirus (BmNPV) is an entomopathogenic and poliorganotrophic virus that infects Bombyx mori. BmNPV consists of a double strand DNA with two distinct phenotypes: the derived polyhedral virus (PDV), responsible for the primary infection in the insect s midgut; and the budded virus (BV), which disperses the infection in the hemocele, causing secondary or systemic infection. It is extremely virulent and when it infects silkworms, causes serious damages to the insect, usually leading to its death or harming the silk production, affecting all the productive chain, leading to economic losses. For a good silk production, a determinant factor is the functioning of the food duct, which is divided in foregut, midgut and hindgut, being the hindgut the place for water and mineral salts absorption and for the end of the digestive process. Several tissues have been established as virus targets, however, others have shown to be resilient to BmNPV. Given the importance of the hindgut, the present paper aimed to verify the susceptibility of its components, ileum, colon and rectum to an geographic isolated of BmNPV in Paraná, Brasil, the BmMNPV. In different post-inoculation days (dpi), the hindgut segment of 5th instar silkworms was dissected and processed for analysis in light microscopy, using conventional dyes and cytochemistry for viral detection and electronic scanning microscopy for the morphological details. The results revealed that the ileum, colon and rectum of the B. mori are constituted by simple epithelium, with alterations in cell morphology, covered by an intima in its luminal side, and that its organization is similar to that of other described insects. The cytological analysis of the ileum, colon and fore rectum revealed that its epithelial cells are not susceptible to BmMNPV in neither of the times analyzed. However, the posterior hindgut or anal duct showed itself to be susceptible to the virus after the 5º dpi, developing all the classic signs described for the infection with AlphaBV, as the presence of viroplasm, nuclear hypertrophy, polyhedra in formation and mature ones. At the end of the infectious cycle, occurs cell lysis with the liberation of viral polyhedra in the intestinal lumen and, consequently, to the external medium, coinciding with the death of the insect. Even with no infection in the other regions of the hindgut, the surrounding tissues have shown infected, affecting the normal functioning of this intestinal region, verified through changes in fecal pellet, which was less compact and changed format. These results will contribute in the establishment of the BmMNPV infectious cycle. Furthermore, the basic knowledge of viral behavior is important for the development of infection control, prevention and previous identification methods of this disease in the field, once it also makes possible the removal of infected silkworms, diminishing the horizontal transmission of the virus in the creation rooms, in a way to reduce the loss of cocoons to be used in the confection of silk yarn / Bombyx mori nucleopolyhedrovirus multiple (BmMNPV) é um vírus entomopatogênico e poliorganotrófico, constituído por DNA fita dupla e apresenta dois fenótipos distintos: o vírus poliédrico derivado, responsável pela infecção primária no intestino médio do inseto; e o vírus broto, que se dispersa na hemocele causando a infecção secundária ou sistêmica. É extremamente virulento e quando infecta lagartas do bicho-da-seda, causa sérios danos ao inseto, geralmente levando-o à morte ou prejudicando a produção da seda, comprometendo toda a sua cadeia produtiva e gerando prejuízos econômicos. Para uma boa produção de seda, um fator determinante é o funcionamento do canal alimentar, que nos insetos é dividido em anterior, médio e posterior, sendo o posterior, local de absorção de água e sais minerais e da finalização do processo digestório. Vários tecidos já foram estabelecidos como alvos do BmMNPV, entretanto outros se mostraram resistentes. Dada a importância do intestino posterior, o presente trabalho objetivou verificar a susceptibilidade de seus componentes, íleo, cólon e reto de lagartas de B. mori do 5° instar ao BmMNPV isolado geográfico do Paraná. Em diferentes dias pós-inoculação (dpi), o intestino posterior foi dissecado e processado para análise em microscopia de luz, utilizando colorações convencionais e citoquímica para detecção viral, e microscopia eletrônica de varredura, para os detalhes morfológicos. Os resultados revelaram que o íleo, cólon e reto de B. mori apresentou morfologia semelhante a de outros lepidópteros. A análise citopatológica do íleo, cólon e o reto anterior revelou que suas células epiteliais não são susceptíveis ao BmMNPV, em nenhum dos tempos analisados. Já o reto posterior ou canal anal, mostrou-se susceptível ao vírus a partir do 5º dpi, desenvolvendo todos os sinais clássicos descritos para a infecção com o AlphaBV, como presença de viroplasma, hipertrofia nuclear, poliedros em formação e maduros. No final do ciclo infeccioso, ocorre a lise celular com a liberação dos poliedros virais para luz intestinal e, consequentemente, para o meio externo, coincidindo com a morte do inseto. Mesmo não havendo infecção nas demais regiões do intestino posterior, os tecidos circunvizinhos se mostraram infectados, o que possivelmente afetou o funcionamento normal desta região, sendo visíveis as modificações na formação do pellet fecal, que se mostrou menos compacto e com alterações no formato. Os resultados obtidos irão contribuir no estabelecimento do ciclo infeccioso deste patógeno. Além disso, o conhecimento básico do comportamento viral é importante para o desenvolvimento de métodos de controle da infecção, prevenção e identificação prévia desta doença no campo, pois, possibilita ainda, a retirada de lagartas infectadas, diminuindo a transmissão horizontal do vírus nos barracões de criação, de forma a reduzir a perda de casulos, a serem utilizados na confecção dos fios de seda

Developing the synthetic control required for the intentional 3-D arrangement of atoms remains a holy grail in crystal engineering and materials chemistry. The explosive development of metal-organic materials in recent decades has shed light on the above problem. Their properties can be tuned by varying the organic and/or inorganic building units. In addition, their crystallinity makes it possible to determine their structures via the X-ray diffraction method. This dissertation will focus on the chemistry and applications of two kinds of metal-organic materials, namely, metal-organic frameworks (MOFs) and metal-organic polyhedra (MOP). MOFs are coordination polymers. Their permanent porosity makes them a good “gas sponge”. In the first section, an isoreticular series of MOFs with dendritic hexacarboxylate ligands has been synthesized and characterized structurally. One of the MOFs in this series, PCN-68, has a Langmuir surface area as high as 6033 m2 g-1. The MOFs also possess excellent gas (H2, CH4, and CO2) adsorption capacity. In the second section, a NbO-type MOF, PCN-46, was constructed based on a polyyne-coupled di-isophthalate linker formed in situ. Its lasting porosity was confirmed by N2 adsorption isotherm, and its H2, CH4 and CO2 adsorption capacity was examined at 77 K and 298 K over a wide pressure range (0-110 bar). Unlike MOFs, MOP are discrete porous coordination nanocages. In the third section, a MOP covered with bulky triisopropylsilyl group was synthesized, which exhibits a thermosensitive gate opening property. This material demonstrates a molecular sieving effect at a certain temperature range, which could be used for gas separation purpose. In the last section, a MOP covered with alkyne group was synthesized through kinetic control. The postsynthetic modification via click reaction with azide-terminated polyethylene glycol turned them into metallomicelles, which showed controlled release of an anticancer drug 5-fluorouracil. In summary, two kinds of metal-organic materials have been discussed in this dissertation, with the applications in gas storage, gas separation, and drug delivery. These findings greatly enrich the chemistry and applications of metal-organic materials.

We present a formal description of `Face Fundamental Transversals' on the faces of the Complexes of polyhedra (meaning threedimensional polytopes). A Complex of a polyhedron is the collection of the vertex points of the polyhedron, line segment edges and polygonal faces of the polyhedron. We will prove that for the faces of any 3-dimensional complex of a polyhedron under face adjacency relations, that a `Face Fundamental Transversal' exists, and it is a union of the connected orbits of faces that are intersected exactly once. While exploring the problem of finding a face fundamental transversal, we have found a partial result for edges that are incident to faces in a face fundamental transversal. Therefore we will present this partial result, as The Edge Transversal Proposition 1. We will also discuss a few conjectures that arose out this proposition. In order to reach our approaches we will first discuss some history of polyhedra, group theory, and incorporate a little crystallography, as this will appeal to various audiences.

Thesis (M.Arch.) - Carleton University, / Accompanying material: 1 CD-ROM located at the Circulation Desk. CD-ROM for the archival copy located at THS. Includes bibliographical references (p. 90-92). Also available in electronic format on the Internet.

Thesis (M.S.) -- Mississippi State University. Computational Engineering. / Title from title screen. Includes bibliographical references.

Le procédé de fabrication de mélanges (PM) consiste à déterminer les proportions optimales à mélanger d'un ensemble de composants de façon que le produit obtenu satisfasse un ensemble de spécifications sur leurs propriétés. Deux caractéristiques importantes du problème de mélange sont les bornes dures sur les propriétés du mélange et l'incertitude répandue dans le procédé. Dans ce travail, on propose une méthode pour la production de mélanges robustes en temps réel qui minimise le coût de la recette et la sur-qualité du mélange. La méthode est basée sur les techniques de l'Optimisation Robuste et sur l'hypothèse que les lois des mélange sont linéaires. On exploite les polytopes sous-jacents pour mesurer, visualiser et caractériser l'infaisabilité du PM et on analyse la modification des bornes sur les composants pour guider le procédé vers le ``meilleur`` mélange robuste. On propose un ensemble d'indicateurs et de visualisations en vue d'offrir une aide à la décision. / The oil blending process (BP) consists in determining the optimal proportions to blend from a set of available components such that the final product fulfills a set of specifications on their properties. Two important characteristics of the blending problem are the hard bounds on the blend's properties and the uncertainty pervading the process. In this work, a real-time optimization method is proposed for producing robust blends while minimizing the blend quality giveaway and the recipe's cost. The method is based on the Robust Optimization techniques and under the assumption that the components properties blend linearly. The blending intrinsic polytopes are exploited in order to measure, visualize and characterize the infeasibility of the BP. A fine analysis of the components bounds modifications is conducted to guide the process towards the ``best`` robust blend. A set of indices and visualizations provide a helpful support for the decision maker.

Made available in DSpace on 2015-03-26T14:00:07Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1123753 bytes, checksum: b46764bbd1d7d69bdb596dd568e0887d (MD5) Previous issue date: 2014-04-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work addresses the Euler s theorem for polyhedra. We present historical facts related to Euler s theorem, some proofs of the theorem and a notion of the Euler-Poincaré characteristic. We also present a material aimed for High School students, with a proof of Euler s theorem using only basic mathematics, discuss a version of the theorem for the plane and use Euler s theorem to show the existence of only five regular convex polyhedra. / Este trabalho aborda o Teorema de Euler para poliedros. Apresentamos fatos históricos relacionados ao Teorema de Euler, algumas demonstrações do teorema e uma noção da característica de Euler-Poincaré. Apresentamos também um material voltado para o Ensino Médio, com uma demonstração para o Teorema de Euler usando apenas Matemática básica, discutimos o caso plano do teorema e usamos o Teorema de Euler para mostrar a existência de apenas cinco poliedros convexos regulares.

A resina epóxi é uma das matrizes mais empregadas na produção de compósitos e revestimentos. Destaca-se no grupo dos materiais termorrígidos devido à facilidade de processamento, suas propriedades mecânicas e à estabilidade térmica. Propriedades como resistência à temperatura e flexibilidade têm sido sistematicamente modificadas pelo uso de diferentes materiais, como argilominerais e, mais recentemente, oligômeros poliédricos de silsesquioxano – POSS, aplicados em matrizes epóxi. Os oligômeros poliédricos de silsesquioxano (POSS) usados na preparação de nanocompósitos termorrígidos têm sido estudados na obtenção de materiais híbridos capazes de suportar temperaturas mais elevadas, promover aumento de propriedades mecânicas e melhorar propriedades de superfície como, por exemplo, a hidrofobicidade do polímero. Os grupos funcionais mais comuns utilizados na preparação de nanocompósitos com resina epóxi são aminas, álcoois e grupos epóxi. A funcionalidade da nanogaiola é importante, uma vez que um termorrígido formado por uma microestrutura reticulada apresente uma microestrutura tridimensional que pode interagir em qualquer direção formando ligações ou interagindo na interface das gaiolas inseridas. Nesse contexto, foi avaliado a influência da adição de três diferentes oligômeros poliédricos de silsesquioxano – POSS (Glicidilisobutil-POSS, Triglicidilisobutil-POSS e Glicidil-POSS), em duas diferentes concentrações 2,5% e 5% (m/m), em resina epoxídica, no comportamento morfológico, mecânico e eletroquímico quando aplicados em aço de baixa liga. Com adição de POSS à resina epóxi, observou-se um aumento na rugosidade e hidrofobicidade do revestimento, além de se obter uma maior resistência à termoxidação e um aumento nos valores de temperatura de transição vítrea do material em comparação com a amostra de resina epóxi. Dentre os sistemas estudados, a amostra contendo Glicidilisobutil-POSS (POSSmono) apresentou os melhores resultados em relação à resistência à corrosão, promovendo um aumento nos valores de ângulo de contato e na impedância eletroquímica. No quesito dispersão na matriz polimérica, o Glicidil-POSS (POSSocta) apresentou uma dispersão ineficiente com a formação de aglomerados, o que hipoteticamente influenciou no seu baixo desempenho no comportamento eletroquímico em relação aos demais sistemas. / Submitted by Ana Guimarães Pereira (agpereir@ucs.br) on 2016-07-05T14:13:46Z No. of bitstreams: 1 Dissertacao Marielen Longhi.pdf: 4767210 bytes, checksum: 8b9878a37cbc71de5a4cf9d89a1553a5 (MD5) / Made available in DSpace on 2016-07-05T14:13:46Z (GMT). No. of bitstreams: 1 Dissertacao Marielen Longhi.pdf: 4767210 bytes, checksum: 8b9878a37cbc71de5a4cf9d89a1553a5 (MD5) Previous issue date: 2016-07-05 / The epoxy resin is one of the matrices most used in manufacturing composites and coatings. It is highlighted in the group of thermosetting materials due to good processability, mechanic behavior and thermal stability. Properties as thermal resistance and flexibility have been systematically modified by the use of different materials, as clays and, more recently, polyhedral oligomeric silsesquioxanes – POSS, applied in epoxy matrices. The polyhedral oligomeric silsesquioxanes (POSS) in thermosetting nanocomposites have been studied in hybrid materials able to support higher temperatures, promoting increase of mechanic properties and improving surface properties such as, for example, the hydrophobicity of the polymer. The most common functional groups used to preparing nanocomposites with epoxy resin are amines, alcohols and epoxy groups. The nanocage functionality is important, once a thermosetting formed by a reticulated microstructure presents a three-dimensional microstructure that can interact in any direction, making bonds or interacting on the interface of the inserted cages. In this context, it was evaluated the influence of three different polyhedral oligomeric silsesquioxanes – POSS (Glycidylisobutyl-POSS, Triglycidylisobutyl-POSS and Glycidyl-POSS), at two different contents 2.5% and 5% (w/w), in epoxy resin, in the morphological, mechanic and electrochemical behavior when applied on low alloy steel. Adding POSS in the epoxy resin, it was observed an increase in roughness and hydrophobicity of the coating. Moreover, it was reached a higher thermal oxidation resistance and an increase in the values of glass transition temperature of the material, regarding the epoxy resin sample. Among the studied systems, the sample containing Glycidylisobutyl-POSS (POSSmono) showed the best results, regarding the corrosion resistance. The addition of POSSmono in the epoxy resin promoted an increase of contact angle and electrochemical impedance values. Regarding the dispersion in the polymeric matrix, the Glycidyl-POSS (POSSocta) presented an inefficient dispersion, with formation of agglomerates, which hypothetically influenced in its low performance in the electrochemical behavior, regarding the other systems.