Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains xi, 107 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 98-101).

On s’intéresse au phénomène d’explosion en temps fini dans les équations aux dérivées partielles paraboliques non linéaires, particulièrement au profil à l’explosion, des points de vue numérique et théorique. Dans la partie théorique, on s’intéresse au phénomène d’explosion en temps fini pour une classe d’équations semi linéaires de la chaleur perturbées fortement avec l’exposant sous-critique de Sobolev. Travaillant dans le cadre des variables auto-similaires, on obtient d’abord l’existence d’une fonctionnelle de Lyapunov, ce qui constitue une étape cruciale pour établir le taux d’explosion de la solution. Dans une seconde étape, on s’intéresse à la structure de la solution au voisinage du temps et du point d’explosion. On classifie tous les comportements asymptotiques possibles pour la solution quand elle s’approche de la singularité. Ensuite, on décrit les profils à l’explosion correspondant à ces comportements asymptotiques. Dans une troisième étape, on construit pour cette équation une solution qui explose en temps fini en un seul point avec un profil d’explosion prescrit. Cette construction s’appuie sur la réduction en dimension finie du problème et sur l’utilisation du théorème de l’indice pour conclure. Dans la partie numérique, on se propose de développer des méthodes afin de donner des réponses numériques à la question du profil à l’explosion pour certaines équations paraboliques, y compris le modèle de Ginzburg-Landau. Nous proposons deux méthodes. La première est l’algorithme de remise à l’échelle (rescaling) proposé par Bergeret Kohn en 1988, appliqué à des équations paraboliques satisfaisant une propriété d’invariance d’échelle. Cette propriété nous permet de faire un zoom de la solution quand elle est proche de la singularité, tout en gardant la même équation. Le principal avantage de cette méthode est sa capacité à donner une très bonne approximation numérique qui nous permet d’atteindre numériquement le profil à l’explosion. Le profil à l’explosion que l’on obtient numériquement est en bon accord avec le profil théorique. De plus, en considérant une équation de la chaleur non linéaire critique avec un terme de gradient non linéaire, avec peu de résultats théoriques, nous énonçons une conjecture sur le profil à l’explosion, grâce à nos simulations numériques. La deuxième méthode numérique s’appuie aussi sur un raffinement de maillage, dans l’esprit de l’algorithme de remise à l’échelle de Berger et Kohn. Cette méthode est applicable à une plus grande classe d’équations dont les solutions explosent en temps fini sans la propriété d’invariance d’échelle. / We are interested in finite-time blow-up phenomena arising in the study of Nonlinear Parabolic Partial Differential Equations, in particular in the blow-up profile, under the theoretical and numerical aspects. In the theoretical direction, we are interested in particular in finite-time blow-up phenomena for some class of strongly perturbed semilinear heat equations with Sobolev subcritical power nonlinearity. Working in the frameworkof similarity variables, we first derive a Lyapunov functional in similarity variables which is a crucial step to derive the blow-up rate of the solution. In a second step, we are interested in the structure of the solution near blow-uptime and point. We classify all possible asymptotic behaviors of the solution when it approaches to the singularity.Then we describe blow-up profiles corresponding to these asymptotic behaviors. In a third step, we construct for this equation a solution which blows up in finite time at only one blow-up point with a prescribed blow-up profile. The construction relies on the reduction of the problem to a finite dimensional one and the use of index theory to conclude. In the numerical direction, we intend to develop methods in order to give numerical answers to the question of the blow-up profile for some parabolic equations including the Ginzburg-Landau model. We propose two methods.The first one is the rescaling algorithm proposed by Berger and Kohn in 1988 applied to parabolic equations which are invariant under a scaling transformation. This scaling property allows us to make a zoom of the solution when it is close to the singularity, still keeping the same equation. The main advantage of this method is its ability to give a very good numerical approximation allowing to attain the numerical blow-up profile. The blow-up profile we obtain numerically is in good accordance with the theoretical one. Moreover, by applying the method to a critical nonlinear heat equation with a nonlinear gradient term, where almost nothing is known, we give a conjecture for its blow-up profile thanks to our numerical simulations. The second one is a new mesh-refinement method inspired by the rescaling algorithm of Berger and Kohn, which is applicable to more general equations, in particular those with no scaling invariance.

En el presente trabajo, estudiamos sobre la reducción de singularidades de un campo vectorial analítico en C2. Presentaremos un resultado de J. Mattei and R. Moussu, esté resultado prueba que después de un número finito de blow-ups las singularidades son simples. PALABRAS CLAVES: Campos vectoriales analíticos, Singularidades, Blow-up. / --- In this work, we study about reduction of singularities of analytic vector fields on C2 . We will present a result of J. Mattei and R. Moussu [7], that result showed that after a finite number of blow-ups the singularities are simple. KEYWORDS: Analytic vector fields, Singularities, Blow-up. / Tesis

Indiana University-Purdue University Indianapolis (IUPUI) / Population genetic structure is difficult to assess in blow flies (Diptera: Calliphoridae) due to high connectivity and genetic diversity of subpopulations. Previous studies revealed high relatedness among individuals within wild samples of blow fly populations, however broad geographic structure was absent. The aim of this research was to determine if blow fly genetic structure exists at a fine spatiotemporal resolution and, if so, to elucidate the influence of environmental factors and resource availability on fly genetics. Specifically, blow fly population genetic patterns were tested against a null hypothesis that flies adhere to a patchy population model with high genetic diversity (i.e. no structure) and high resource availability. Samples of the black blow fly, Phormia regina Meigen (Diptera: Calliphoridae), were collected at six urban parks in Indiana, USA (=urban) in 2016 and 2017 (N = 14 and 16 timepoints, respectively). Additional sampling in different ecoregions was performed to determine if trends observed at a high-resolution scale were also present at a broad geographic scale. Therefore, P. regina were also collected at four sites within two national parks (the Great Smoky Mountains and Yellowstone National Parks) over a three-day period. Randomly selected females (N = 10) from each sample underwent the following analyses: 1) gut DNA extraction, 2) molecular analysis at 6 microsatellite loci, 3) vertebrate-specific 12S and 16S rRNA sequencing, and, 4) vertebrate fecal metabolite screening. Flies from the national parks and a comparable subset of urban data also underwent stable isotope analysis (SIA) to determine larval food source. Overall, strong seasonal population genetic structure was observed over both years in the urban environment (2016 F’ST = 0.47, 2017 F’ST 0.34), however spatial structure was lacking, as seen in previous studies (2016 F’ST = 0.04, 2017 F’ST 0.03). Weather conditions prior to and on the day of blow fly collections, interspecific competition, and resource availability greatly impacted the genetic diversity and kinship of P. regina. A total of 17 and 19 vertebrate species were detected by flies in 2016 and 2017, respectively, and many flies tested positive for vertebrate feces, suggesting that many varied resources are important for maintaining high gene flow among geographic locations. Genetic diversity was non-existent in flies collected from the Smokies (F’ST = 0.00), while very slight spatial structure existed in the Yellowstone populations (F’ST = 0.07). Environmental factors such as temperature, humidity, and wind speed were all statistically relevant in maximizing fly collections with vertebrate resources. In 720 min of total sampling time in the national parks and a subset of urban data, 28 vertebrate species were identified, and fecal resources appeared to be the most abundant in Yellowstone. Stable isotope analysis revealed a majority of larval resources in the national parks were herbivores, with a more even distribution of carnivore and herbivore carcasses present in the urban environment, which likely explains the high genetic diversity of adult flies in these regions. Overall, the null hypothesis that P. regina adheres to a patchy population model could not be rejected for the Smokies populations. However, the urban and Yellowstone populations appear to adhere to a Levins metapopulation model in which variable availability in resources leads to random bottleneck events in the local populations. Overall, environmental conditions, competition, and resource availability are all important factors influencing P. regina population genetic structure in different environments.

The "Water-Blow" Pulsation generator has been used to produce pulsing fluid flow in an off-the-shelf industrial single pass heat exchanger containing 5/8 in. 0. D. tubes, 37 inches long. Experimental results showed that heat transfer from steam to flowing water could be enhanced by as much as 100%, although a more practical enhancement would likely be about 40%. From the experimental results it was estimated that pulsing air requirement (standard cu. ft. air per cu. ft. water) increased linearly from about 0 to 4.0 over a range of heat transfer enhancement from 0 to 40%. Two factors which influenced pulsing air requirement were the air surge volume sizes and the pressure fluctuations which occurred therein. / Thesis / Master of Engineering (ME)

Forensic entomology is a well-established science linking arthropod biology and ecology to legal investigations. Specifically, immature development on a decomposing corpse may give insight into the minimum time elapsed since death. Until recently, biological variation within a single species has been overlooked when estimating colonization events. Variation in the form of phenotypic plasticity, or the ability of a single genotype to produce multiple phenotypes under alternative stresses, has been documented in genetic and ecological literature and spans across all phyla. Taking this into account, different subpopulations of forensically pertinent insect species should also possess the ability to adapt to changing environments as geographic distribution increases. Thus, plastic responses of a species to alternative stresses may be measured in biological parameters, such as development time. In this research, three geographically distinct strains of the blow fly Cochliomyia macellaria Fabricius (Diptera Calliphoridae) were reared in two distinct environments in order to measure development time, as well as pupal and adult masses. Strains exhibited genetic variance when compared to each other, and each strain exhibited variable responses across environments (phenotypic plasticity). Plasticity in the form of genotype by environment (GxE) interactions was also exhibited by C. macellaria, although consistent adherence to any single rule explaining ontogenetic trends was not apparent. This research supports the existence of intraspecific variation in a common blow fly of forensic importance. Results of this study will impact the forensic entomology community by encouraging the generation of either strain;specific developmental datasets or statistical models to minimize variation caused by genetic, environment, or GxE effects in order to compare developmental data across strains.

Polyethylene Terephthalate (PET) has become the preferred material of choice for many packaging applications. A preference over glass due to its low weight, similar transparency to glass and cost consideration, including the availability of recycled PET feedstock via kerbside collection has provided newer opportunities for hot-fill applications. Ostensibly, this material is used for beverage markets requiring cold and hot filling (85 oC) of liquid foods. However due to the poor thermal stability of PET - due to its low glass transition temperature - an increase in elevated temperatures limits the number of market segments the material can be utilised. Current practices incorporate the heat-set process, aimed at improving the crystallisation kinetics within the amorphous and crystalline region. This body of work incorporates a single stage Injection Stretch Blow Moulding machine (ISBM). Modifications to conventional carbonated soft drink (CSD) beverage containers to include heat-set capabilities are incorporated. The current research study investigates the potential benefits of RPET blends for improving thermal stability at elevated temperatures. This study investigates changes in mechanical properties which include • Youngs modulus, • top load strength, • burst strength, • Thermal analysis specifically investigating changes in • Glass transition temperature, • enthalpy changes due to heat-set conditions • Percentage crystallinity changes as a function of heat-set conditions Rheological characteristics to all materials used were investigates. Furthermore, changes in the physical properties to each PET beverage container were investigated which include; • process shrinkage (S1), • hot-fill shrinkage (S2) • Density changes via optimised DoE parameters. A combination of cold (80 oC) and hot moulds (150 oC) as measured via Forward Looking Infrared (FLIR) at the exterior to the blow mould and their affect on percentage crystallinity was studied. Preform surface temperature (PST) and strain induced crystallinity, assisting in molecular relaxation is analysed. Upon completion to an exhaustive experimental ISBM trial, a DoE software package - in this case Echip - was used to analyse and predict optimised hot-fill shrinkage values of 2.5 percent with a maximum constrained RPET blend value totalling 40 percent. ISBM optimised conditions demonstrated advantages when combining an increased preform surface temperature, RPET blends and optimised ISBM process conditions as indicated via the DoE at low heat-set temperatures.

In 2002, Feldman, Ilmanen, and Knopf constructed the first example of a non-trivial (i.e. non-constant curvature) complete non-compact shrinking soliton, and conjectured that it models a Ricci flow singularity forming on a closed four-manifold. In this thesis, we confirm their conjecture and, as a consequence, show that limits of blow-ups of Ricci flow singularities on closed four-dimensional manifolds do not necessarily have non-negative Ricci curvature. / text

Orientador: Rafael Zadorosny / Resumo: As propriedades diferenciadas de materiais nanoestruturados, provenientes do efeito de escala, tem chamado muita atenção nos últimos anos. Tais características, fazem desses materiais propícios para o emprego em nanoeletrônica, nanofiltração, engenharia tecidual e outros. Isso, aliado a miniaturização dos dispositivos, tem gerado uma grande demanda por materiais com características aprimoradas, desenvolvimento de novas técnicas de produção e aprimoramento das já existentes, tudo isso associado a um menor custo de produção e uma maior produtividade. Neste trabalho é apresentado um estudo sobre o emprego da técnica de “Solution Blow-spinning” (SBS) na produção de nano e microfios supercondutores dos sistemas cerâmicos (TR)BCO e BSCCO. Esta recente técnica tem se destacado por apresentar maior taxa de produção, baixo custo e fácil implementação quando comparado com técnicas já consolidadas. Primeiramente foram produzidas fibras de PVP puro onde foi possível extrair informações referentes às variáveis de produção tais como: taxa de injeção, pressão do ar, distância de trabalho e escolha do diâmetro da agulha interna. Em seguida, a produção dos nano/microfios de YBa2Cu3O7- δ (YBCO) obtidos por SBS revelaram detalhes referente à produtividade, reprodutibilidade e das características morfológicas dos fios cerâmicos obtidos com o emprego da referida técnica. Posteriormente, as melhores condições de síntese observadas na produção do YBCO foram utilizadas na obtenção dos nano/microfios... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The single properties presented by nanostructured materials is due to a scale effect and have been attracted much attention in recent years. Such characteristics make these materials suitable for applications in nanoelectronics, nanofiltration, tissue engineering and so on. These issues coupled with the miniaturization of the devices, have generated a great demand for materials with improved characteristics, development of new production techniques and improvement of the existing ones. All such things are associated with lower production costs and higher productivity. In this work is presented a study focused on the use of the "Solution Blow-spinning" technique (SBS) in the production of superconducting nano and microwires of the ceramic systems (TR)BCO and BSCCO. This new technique has payed attention due to its higher production rate, low cost and easy implementation when compared to other consolidated techniques. First, pure PVP fibers were produced to obtain information related to the production variables such as: injection rate, air pressure, working distance and choice of the internal needle diameter. Then, the production of nano/microwires of YBa2Cu3O7- δ (YBCO), obtained by SBS, revealed details regarding the productivity, reproducibility and morphological characteristics of the ceramic wires. Consequently, the best synthesis conditions were used to obtain the GdBa2Cu3O7- δ (GdBCO) and Bi2Sr2CaCu2O8+x (BSCCO) superconducting nanowires. Finally, SEM analysis confirmed ... (Complete abstract click electronic access below) / Doutor

abstract: Following the Restoration of the English monarchy in 1660, musical culture gradually began to thrive under the support of royal patronage and the emerging middle class. The newly crowned Charles II brought with him a love of French music acquired during his time in exile at the court of his cousin, the young Louis XIV. Organ builders, most notably Bernard Smith and Renatus Harris, brought new life to the instrument, drawing from their experience on the Continent to build larger instruments with colorful solo stops, offering more possibilities for performers and composers. Although relatively few notated organ works survive from the Restoration period, composers generated a niche body of organ repertoire exploring compositional genres inspired by late 17th-century English instruments. The primary organ composers of the Restoration period are Matthew Locke, John Blow, and Henry Purcell; these three musicians began to take advantage of new possibilities in organ composition, particularly the use of two-manuals with a solo register, and their writing displays the strong influence of French and Italian compositional styles. Each adapts Continental forms and techniques for the English organ, drawing from such forms as the French overture and récit pour le basse et dessus, and the Italian toccata and canzona. English organ composers from the Restoration period borrow form, stylistic techniques, ornamentation, and even direct musical quotations, to create a body of repertoire synthesizing both French and Italian styles. / Dissertation/Thesis / Doctoral Dissertation Music 2014