No description available.

Master of Science / Department of Mechanical and Nuclear Engineering / Jeremy Roberts / The reactivity method is an indirect nondestructive technique to estimate integral burnup in fuel elements. In this method, the assumption is made that reactivity worth of a fuel element is a known function of burnup, often a linear relationship. When a fuel element burns, reactivity is reduced due to depletion of fissile actinides and generation of neutron-absorbing fission products. Currently, there is a lack of experimental data to verify the current composition of the KSU TRIGA (Training Research Isotopes General Atomics) fuel. Moreover, the KSU TRIGA Mark II staff method of estimating burnup is admittedly inaccurate due to its simple approximations. This work presents the positive period technique as convenient method use only the excess reactivity of the KSU core to compute reactivity via the inhour equation. Period measurements are determined via extraction and manipulation of the time dependent power data in the measurements. MCNP and Serpent modeling codes are both used extract the neutron kinetics parameters necessary in the inhour equation. Seven axial discretization of the KSU fuel was modeled, which minimizes the reactivity biases as function of burnup. Moreover, two unit cell models of the KSU TRIGA fuel were investigated. Modeled reactivity worths were computed using the KCODE in MCNP for comparative analysis. The burnup steps using two power peaking factor methods were developed to account for the biases introduced initial burnup of fuel prior to installation at KSU. By using the error distribution given by the two method to generate 200 test cases of the burnup steps can yield to reactivity worths as a function of burnup with quantifiable uncertainties. Finally, the results suggest that validation from another nondestructive technique such as gamma spectroscopy is necessary to asses the reactivity biases observed for higher burnup fuel elements due to unknown radial orientations. This work ultimately supports the production of a high-fidelity model of the KSU reactor.

The purpose of this experiment has been to complete a challenging thesis production in the style and technique of Open Theatre, utilizing imaginative production effects. The purpose was also to provide a valuable experience for those actors and technicians involved, meeting the standards and requirements of educational theatre. The experiment evolved from adapting, designing, directing, and producing a twelve scene cutting from Megan Terry's Viet Rock and twelve episodes from Jean-Claude van Italliets The Serpent. The study was culminated with a one-evening performance of The serpent and Viet Rock on August 10, 1971. The style and technique of Open Theatre seemed to be well accepted and fulfilled the requirements which the script demanded. The reaction of the audience seemed to indicate that the response sought by the Comp any was accomplished. The conclusion may also be drawn that this experimental production was successful not only as art, but also as an evening of entertainment.

Nous considérons une fonction polynomiale de deux variables réelles qui s’annule à l’origine et qui a un minimum local strict en ce point. Nous nous plaçons dans un voisinage de l’origine dans lequel les lignes de niveau non nulles de cette fonction sont des courbes de Jordan lisses. Chaque fois que l’origine est un point critique de Morse, les niveaux suffisamment petits deviennent des bords de disques convexes. Si l’origine n’est pas de Morse, ces courbes de niveau peuvent ne pas être convexes, comme l’a montré Coste.Le but de cette thèse est double. Tout d'abord, nous nous intéressons à la construction d’exemples de minimums locaux stricts et non-Morse dont les lignes de niveau suffisamment petites sont loin d’être convexes. Et deuxièmement, nous étudions un objet combinatoire mesurant cette non-convexité : l’arbre de Poincaré-Reeb de la restriction de la première coordonnée à la région délimitée par une ligne de niveau donnée. Ces arbres planaires sont enracinés et leurs sommets correspondent en gros aux points de la courbe où les tangentes sont verticales.L’objectif principal de notre étude est de caractériser tous les types topologiques possibles d’arbres de Poincaré-Reeb. À cette fin, nous construisons une famille d’exemples réalisant une grande classe de tels arbres. Dans un premier temps, nous concentrons notre attention sur le cas des polynômes d’une variable, en utilisant un outil inspiré du travail de Ghys. L’un de nos résultats principaux donne une preuve nouvelle et constructive de l’existence de polynômes de Morse dont la permutation associée (appelée «le serpent d’Arnold») est séparable. / We consider a real bivariate polynomial function vanishing at the origin and exhibiting a strict local minimum at this point. We work in a neighbourhood of the origin in which the non-zero level curves of this function are smooth Jordan curves. Whenever the origin is a Morse critical point, the sufficiently small levels become boundaries of convex disks. Otherwise, these level curves may fail to be convex, as was shown by Coste.The aim of the present thesis is twofold. Firstly, to construct examples of non-Morse strict local minima whose sufficiently small level curves are far from being convex. And secondly, to study a combinatorial object measuring this non-convexity, namely the Poincaré-Reeb tree of the restriction of the first coordinate to the region bounded by a given level curve. These planar trees are rooted and their vertices roughly speaking correspond to points on the curve with vertical tangent lines.The main objective of our study is to characterise all possible topological types of Poincaré-Reeb trees. To this end, we construct a family of examples realising a large class of such trees. As a preliminary step, we restrict our attention to the univariate case, using a tool inspired by Ghys’ work. One of our main results gives a new and constructive proof of the existence of Morse polynomials whose associated permutation (the so-called “Arnold’s snake”) is separable.

Ce manuscrit porte sur l'étude d'une structure robotique originale dont le système de propulsion s'inspire du mode de locomotion par progression rectilinéaire des serpents. La structure proposée dérive d'un prototype développé par l'entreprise TDA et comprend plusieurs modules dotés de 4 mécanismes locomoteurs solidaires entrainés par un moteur. Une partie des travaux de thèse porte sur l'analyse et l'optimisation du mécanisme. L'analyse du déplacement d'un modèle du prototype existant par un simulateur robotique intégré, réalisé à l'aide de bibliothèques à code source ouvert, a montré la nécessité de le modifier. Ainsi, le nombre de mécanismes locomoteurs par module passe de 8 à 4 et les liaisons inter-modulaires du nouveau robot sont des rotules actives ou passives selon les directions. Un algorithme de suivi de trajectoire est proposé et des simulations ont permis de le valider.

This investigation into embodied female spirituality clearly required an approach which was able to holistically engage all human faculties - different aspects of mind, body, spirit, intuition and memory. Consequently it was essential to use my creative practice as an integrative aspect of the research. I have used my creative practice across health and healing, Sufi processes and light based media to investigate, develop and practice 'embodied female spirituality'. A shamanic-performance paradigm and feminism have been central, philosophically, to the study. In addition I have chosen to explicate the connections between these discourses of the body, the text and the imagery through my own story, my autobiography. The methodology involves two research strategies; the use of creative practice as research and the use of autobiography as a research tool. The creative practice can be seen as a continuum of modalities, extending from the private to the public. Three dimensions of the practice will be discussed. The following is a description of the dimension of a typical session in (1) a body-based natural therapy treatment I deliver (2) a group-body-based Sufi session I deliver and (3) a brief outline of the approach I have taken to the research within light based media and a list of the works.

This thesis compares the impact on disk performance in a GNU/Linux  environmentwith three encryption algorithms: AES,  Serpent and Twofish in three different implementations: DM-crypt, Loop-AES and Truecrypt. For all three algorithms a key length of 256 bits is used. The thesis shows that the least performance impact during data encryption, and thus file writing, is reached by using AES or Twofish encryption implemented in DM-crypt or TrueCrypt. The thesis shows that some data operations with a sufficiently low processor utilization barely affects disk performance at all if encrypted using the optimal implementation and algorithm. It is also discovered that the performance impact during data decryption, or file reading, can be minimized by using the most efficient implementation and algorithm. The best results are met with the AES or Twofish cipher, regardless of implementation. An important conclusion that  is  drawn is that it is hard to determine a superior encryption solution for all purposes. However, by reviewing and examining the collected data from all aspects of disk performance the AES implementation in TrueCrypt is, with small marginals, determined to be the most optimal. / Undersökningen jämför hur krypteringsalgoritmerna AES, Serpent och Twofish implementerade i DM-crypt, Loop-AES och TrueCrypt påverkar diskprestandan i en GNU/Linux-miljö. Samtliga krypteringsalgoritmer tillämpas med en nyckellängd på 256 bitar. Undersökningen visar att högst skrivhastighet och således krypteringshastighet uppnås med algoritmerna AES och Twofish i DM-crypt eller Truecrypt. Krypteringens påverkan på diskprestanda är beroende av vilka typer av operationer som utförs och hur hög processorsysselsättningsgraden är. Vid  simplare  I/O-operationer har  den mest optimala  krypteringslösningen knappt någon påverkan på diskprestandan överhuvudtaget. Undersökningen visar också att påverkan av prestanda vid dekryptering är minst vid tillämpning av AES eller Twofish oavsett implementering. En viktig slutsats som dras är att det inte finns en överlägsen krypteringslösning för samtliga användningsområden. Genom att sammanställa och granska insamlad data gällande samtliga aspekter beträffande diskprestanda fastställs TrueCrypts implementation av AES till att vara den mest optimala, trots små marginaler.

In this dissertation I examine the role played by the ancient Near Eastern serpent in apotropaic and prophylactic magic. Within this realm the serpent appears in roles in healing and protection where magic is often employed. The possibility of positive and negative roles is investigated. The study is confined to the Bronze Age in ancient Egypt, Mesopotamia and Syria-Palestine. The serpents, serpent deities and deities with ophidian aspects and associations are described. By examining these serpents and deities and their roles it is possible to incorporate a comparative element into his study on an intra- and inter-regional basis. In order to accumulate information for this study I have utilised textual and pictorial evidence, as well as artefacts (such as jewellery, pottery and other amulets) bearing serpent motifs. / Old Testament & Ancient Near Eastern Studies / M.A. (Ancient Near Eastern Studies)

This study has been prepared for the purpose of showing the development of the modern bass tuba through all stages, from its earliest ancestors to its present form. Also by the use of examples, it is hoped that the treatment of the instrument in selected orchestral works will show in some ways how it has and can be used.

As doenças neurodegenerativas (DN), incluindo doença de Alzheimer e doença de Parkinson, estão entre as principais causas de mortalidade e morbidade nos países ocidentais. Não há ainda um tratamento definitivo para estas neuropatias, mas os estudos têm apontado para mecanismos comuns de toxicidade, que incluem disfunção mitocondrial, estresse oxidativo e apoptose. Assim, as mitocôndrias constituem alvos importantes para futuras estratégias de neuroproteção visando tratar, prevenir ou retardar a neurodegeneração. A biodiversidade da fauna brasileira representa uma fonte promissora e ainda pouco explorada de novas moléculas com (i) atividade neuroprotetora e, portanto, potencial para originar novos fármacos para o tratamento destas doenças; ou ainda com (ii) atividade neurotóxica, podendo ser utilizadas como ferramentas de estudo de mecanismos de neurotoxicidade. O presente estudo teve por objetivo investigar o possível potencial neuroprotetor e/ou neurotóxico de peptídeos de baixo peso molecular, obtidos a partir do veneno de diferentes espécies de serpentes do gênero Bothrops por meio da investigação dos efeitos destes compostos na função mitocondrial de cérebro de rato. Duas das frações estudadas (obtidas a partir do veneno da B. atrox e da B. jararaca) apresentaram um interessante potencial protetor contra o intumescimento osmótico mitocondrial e a produção de espécies reativas de oxigênio (ERO), eventos associados à transição de permeabilidade mitocondrial e à morte celular. Por outro lado, outra fração, obtida a partir do veneno da B. pirajai, apresentou potencial neurotóxico. Estes achados podem ser úteis para estudos mecanísticos e também no estabelecimento de futuras estratégias de tratamento das doenças neurodegenerativas, tendo as mitocôndrias como alvos terapêuticos (terapia alvo). / The neurodegenerative diseases, including Alzheimer\'s and Parkinson\'s diseases, are among the main causes of morbidity and mortality in Western countries. A definitive treatment for these neuropathies has not yet been found, but studies have indicated common mechanisms of toxicity, including mitochondrial dysfunction, oxidative stress and apoptosis. Therefore, mitochondria represent important targets for the future neuroprotective strategies aimed to treat, prevent or delay the neurodegeneration. The Brazilian fauna biodiversity represents a promising and under explored source of new molecules with (i) neuroprotective activity and potential to originate new drugs for the treatment of these diseases; or yet, with (ii) neurotoxic activity, representing tools to study neurotoxicity mechanisms. The present study aimed to investigate the possible neuroprotective and/or neurotoxic potential of low-molecular-mass peptides extracted from the venom of different species of Bothrops genus snakes by investigating their effects on rat brain mitochondrial function. Two of the studied fractions (from B. atrox and B. jararaca venoms) presented an interesting protective potential against both the mitochondrial swelling and reactive oxygen species (ROS) production, events associated with mitochondrial permeability transition and cell death. On the other hand, other fraction (from B. pirajai venom) presented a neurotoxic potential. These findings might be useful for mechanistic studies and also for the establishment of future strategies of neurodegenerative diseases treatment, using mitochondria as therapeutic targets (targeted therapy).