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Ο περιορισμός αλυσιδωτών μακρομορίων σε νανο-πόρους με διαστάσεις συγκρίσιμες με τις χαρακτηριστικές διαστάσεις της μοριακής αλυσίδας όπως και η δυνατότητα αποδέσμευσης (απελευθέρωσης) της αλυσίδας από το νανο-πόρο παίζουν σημαντικό ρόλο σε πολλές βιολογικές διαδικασίες και βιοτεχνολογικές εφαρμογές. Η διαδικασία της αποδέσμευσης μιας αρχικά εγκλωβισμένης πολυμερικής αλυσίδας εξαρτάται από μια σειρά παράγοντες όπως: το μοριακό βάρος της αλυσίδας, το μέγεθος του νανο-δοχείου σε σχέση με το μήκος της αλυσίδας, το σχήμα του νανο-δοχείου, το μέγεθος του πόρου διαφυγής/εισόδου της αλυσίδας στο νανοδοχείο, η ποιότητα του διαλύτη εντός και εκτός του νανοδοχείου κ.α. Το φαινόμενο και ο ρόλος των παραμέτρων που το επηρεάζουν θα μελετηθούν με αναλυτικές μεθόδους περιγράφοντας το μακρομόριο με μοντέλα ιδανικών αλυσίδων και το νανοδοχείο ως ένα αδιαπέραστο περιορισμό (σφαιρικού σχήματος) με ένα πόρο διαφυγής για την αλυσίδα. Η μελέτη αυτή αποτελεί το πρώτο βήμα για την εφαρμογή ρεαλιστικών μοντέλων για την περιγραφή των διαδικασιών δέσμευσης/αποδέσμευσης γραμμικών πολυμερών σε σφαιρικές κοιλότητες νανοσκοπικών μεγεθών. / The confinement of the macromolecules into nanopores with dimensions translocation of the chain through the nanopore has a key role in many biological processes and biotechnological applications. The process of packing/releasing of the polymer chain depends on many factors like molecular weight of the chain, the size of the nano-container in comparison with the length of the chain, the shape of the nano-container, the size of the nanopore, the quality of the solvent into and out of the nano-container etc. In the present work we will study the translocation of an ideal chain, confined initially into an impenetrable spherical cavity, through a tiny pore on the surface of the spherical cavity. Using analytical tools and Monte Carlo simulations we examine the effects of the molecular weight and the size of the spherical cavity in the translocation process. This study is a first step towards more realistic descriptions of the confinement/translocation problem of linear polymers from nanopores.

The steady flow model is applied to ablatively accelerated spherical targets for inertial confinement fusion. A parameter study is conducted which identifies regions of good hydrodynamic efficiency. In the limit of very large acceleration the model is seen to become planar and can be used to treat some large aspect ratio shells. A model of charged particle beam driven ablation is presented. The ablation resulting from this form of energy deposition can resemble laser driven albation in some cases, but qualitatively different behavior occurs in certain regimes of the beam power and range. Laser energy deposition by inverse bremsstrahlung is also included. A procedure for descaling the dimensionless results of the steady flow model is presented. This allows for comparison of the model with experiments and numerical simulations.

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Conventional fiber reinforced polymers (FRPs) require polymers such as epoxies that are not biodegradable, which have a significant impact on the environment. The first phase of the thesis aims at replacing conventional polymers with sustainable bio-polymers. The tensile mechanical properties of glass-FRP (GFRP) laminates using two types of organic furfuryl alcohol bio-resins extracted from renewable resources, such as corncobs, were investigated. Results are compared to control specimens fabricated using conventional epoxy resin. It was shown that by careful selection of viscosity of bio-resin, and type and dosage of catalyst, similar mechanical properties to epoxy-GFRP can be achieved. The second and third phases consisted of durability testing of the bio-resin GFRP. A total of 160 tension coupons and 81 unconfined and confined concrete cylinders wrapped with bio-resin-GFRP were studied. Conditioning was achieved by immersion of the specimens in saline solutions with 3% salt concentration, at 23, 40 and 55 degrees Celcius, for up to 300 days. Specimens were compared to epoxy-GFRP specimens aged in the same environment. Deterioration was quantified by tensile testing of the coupons and compression testing of the cylinders at various stages of exposure. The bio-resin-GFRP showed 33% less tensile strength retention than the epoxy-GFRP. The epoxy-GFRP and bio-resin-GFRP wrapped cylinders had the same un-aged confined axial compressive strength (fcc’), essentially a strengthening ratio (fcc’/fc’) of 2.24. After 300 days, the (fcc’/fc’) ratio retentions for the bio-resin-GFRP was 73% at all temperatures. Using the Arrhenius model, it was predicted that 61% retention in tensile strength of the bio-resin-GFRP and 65% retention of the compressive strength of wrapped cylinders would occur after 100 years in an environment with a mean annual temperatures of 10 degrees Celcius. / Thesis (Master, Civil Engineering) -- Queen's University, 2013-08-24 00:02:25.683

FRANCAIS: L'observation d'une intense luminescence dans les super-réseaux de Si/SiO2 a ouvert de nouvelles avenues en recherche théorique des matériaux à base de silicium, pour des applications éventuelles en optoélectronique. Le silicium dans sa phase cristalline possède un gap indirect, le rendant ainsi moins intéressant vis-à-vis d'autres matériaux luminescents. Concevoir des matériaux luminescents à base de silicium ouvrira donc la voie sur de multiples applications. Ce travail fait état de trois contributions au domaine. Premièrement, différents modèles de super-réseaux de Si/SiO2 ont été conçus et étudiés à l'aide de calculs ab initio afin d'en évaluer les propriétés structurales, électroniques et optiques. Les deux premiers modèles dérivés des structures cristallines du silicium et du dioxyde de silicium ont permis de démontrer l'importance du rôle de l'interface Si/SiO2 sur les propriétés optiques. De nouveaux modèles structurellement relaxés ont alors été construits afin de mieux caractériser les interfaces et ainsi mieux évaluer la portée du confinement sur les propriétés optiques. Deuxièmement, un gap direct dans les modèles structurellement relaxés a été obtenu. Le calcul de l'absorption (par l'application de la règle d'or de Fermi) a permis de confirmer que les propriétés d'absorption (et d'émission) du silicium cristallin sont améliorées lorsque celui-ci est confiné par le SiO2. Un décalage vers le bleu avec accroissement du confinement a aussi été observé. Une étude détaillée du rôle des atomes sous-oxydés aux interfaces a de plus été menée. Ces atomes ont le double effet d'accroître légèrement le gap d'énergie et d'aplanir la structure électronique près du niveau de Fermi. Troisièmement, une application directe de la théorique des transitions de Slater, une approche issue de la théorie de la fonctionnelle de la densité pour des ensembles, a été déterminée pour le silicium cristallin puis comparée aux mesures d'absorption par rayons X. Une très bonne correspondance entre cette théorie et l'expérience est observée. Ces calculs ont été appliqués aux super-réseaux afin d'estimer et caractériser leurs propriétés électroniques dans la zone de confinement, dans les bandes de conduction. / ENGLISH: The observation of intense luminescence in Si/SiO2 superlattices has opened up new vistas in theoretical research, with a view to fabricate Si-based devices suitable for optoelectronic applications. Crystalline silicon has an indirect energy gap that makes this material less competitive compared to other luminescent materials. The fabrication of silicon-based luminescent materials would thus provide multiple applications in the future. Three achievements are presented in this work. (a) Several Si/SiO2 superlattice models have been constructed and studied within a first-principles framework in order to evaluate their structural, electronic and optical properties. The first two models are derived from crystalline phases of silicon and silicon dioxide. From these models, the interfaces are shown to play a significant role on their optical properties. New structurally-relaxed models have thus been constructed in order to satisfy more closely the interface topology and evaluate accurately the confinement effects on their optical properties. (b) Direct bandgaps are obtained in the structurally-relaxed models. Their absorption coefficient has been calculated (by applying the Fermi Golden rule) and compared to that of bulk Si, giving a clear demonstration of the enhanced absorption (and emission) properties of Si confined systems, compared to bulk Si. A blueshift with increased confinement has been confirmed. Furthermore, the precise role of suboxide Si atoms at the interfaces has been investigated. These suboxides are shown to have two main effects: (i) increase slightly the energy gap; (ii) reduce the dispersion in the band structure near the Fermi level. (c) A direct application of the Slater transition state theory applied to crystalline silicon has been performed and compared to X-Ray near-edge absorption spectroscopy measurements. The Slater transition state theory constitutes a subset of the density functional theory for ensembles. Very good agreement between this theory and the experiment is obtained. This type of calculations has been applied to the Si/SiO2 superlattices in order to estimate and characterize the electronic properties of the confined region in the conduction bands.

Mesoscopic devices, such as nano-wires, are of interest for the next step in creating spintronic devices. With the ability to manipulate electrons and their spin, spintronic devices may be realised. To that end the different effects found in low-dimensional devices must be studied and understood. In this thesis  the influence that lateral spin-orbit coupling (LSOC) has on a nanowire, with asymmetrical confinement potential, is studied. The nanowire is studied through a numerical approach, using the Hartree-Fock method with Dirac interactions to solve the eigenvalue problem of an idealised infinite nanowire. The nanowire has a split-gate that generates the electrostatic asymmetrical confinement potential. It is found that the lateral spin-orbit coupling has little to no effect without any longitudinal effects in the wire, such as source-drain bias. The electrons will spontaneously create spin-rows in the device due to spin polarization. The spin polarization is triggered by using LSOC, numerical noise or from a weak magnetic field. / Mesoskopiska anordningar, som nano-trådar, tros vara ett viktigt steg för att skapa spinnelektronik. För att kunna skapa spinnelektronik behövs kunskap om hur elektroner kan manipuleras. Generellt måste därför existerande fenomen i nanoelektronik studeras. I denna avhandling studeras hur ''lateral spin-orbit koppling'' (LSOC) influerar en nanotråd som har en asymmetrisk potentialbarriär. Hartree-Fock metoden, med Dirac potential för elektron-elektron interaktioner, användes för att beräkna energinivåerna för en idealisk, oändligt lång nanotråd. Nanotråden har en split-gate som alstrar den elektrostatiska, asymmetriska potentialbarriären. "Lateral spin-orbit koppling" visar sig ha minimal effekt då longitudinella effekter, exempelvis spänning, saknas. Elektronerna placerar sig spontant i spinn-rader i tråden vid spontan spinn polarisation. Spinn polarisationen sätts igång av LSOC, numeriska störningar eller från svagt pålagt magnetfält.

Background: Segregation, within the context of this study, is the removal of a prisoner from the wider prison to an environment that is regimented and controlling, and functions through enforced solitude. There is very little research that explores this environment from the perspective of the prisoners who experience it. By using the voices of the prisoners this study provides rich description of the conceptual understanding of how they and resolved their segregation experiences. Research Aim: The aim of this research was to develop a grounded theory of how prisoners gave meaning to their segregated environment experience. Methodology: This study was guided by a constructivist epistemology and the principles and process of grounded theory (Constructivist Grounded Theory) as described by Glaser, Strauss, and Charmaz. Data was gathered from a participant group of prisoners who were experiencing, or had experienced within the previous two months, time in segregation, from one specific Category A prison, as well as comparable case studies. Data was collected through semi structured interviews, and case study documentary analysis, and analysed using the concurrent processes of constant comparative analysis, data collection, and theoretical sampling. Results: The participants expressed that the main concern of their time in segregation was a desire to survive this experience. They expressed this desire, and the actions and behaviours necessary to achieve it, through a process conceptualised as reframing contextual power. This has three 'subcategories‘ 'Power Posturing', 'Power Positioning', and 'Power Playing', each comprising of further subdivisions of the conceptualisation of the participants main concern. These consisted of 'Knowing Fixed Rules', 'Reading Emergent Rules', 'Relating', 'Resistance', 'Being Bad', 'Being Mad', and 'Being Cool'. Power was the major interlinking concept and this was fundamental to the strategies and actions necessary for the participants to achieve their main concern. While presented as three distinct 'subcategories‘ they are neither independent nor hierarchical, rather they are interconnected and interlinked. The participants were active in the utilisation and enactment of power actions and not passive recipients of power. A theoretical exploration of the power inherent in reframing contextual power demonstrated that no one theory or approach can sufficiently explain power within this context. It is proposed that, drawing from a number of theorists, an integrated approach to viewing and understanding such power is required to allow for a more sophisticated understanding of how the participants reframe contextual power. Conclusions: The findings of this study provide a method of understanding how the participants engaged with, and utilised complex strategies to survive the segregated environment experience. The findings also contribute to how we understand the processes of power within this current (and similar) context(s). I consider that the uniqueness of this thesis is important as it contributes to the extant body of knowledge in this field and thus offers a salient message relating to the (potential) future of segregation and the solitary confinement of prisoners.

Ce mémoire en recherche-création explore l’enfermement volontaire et les différents types de tensions qu’il provoque. Court roman prenant la forme du journal intime, La Parenthèse met en scène un jeune homme qui décide de s’enfermer chez lui une semaine durant et s’interdit tout contact avec l’extérieur – autant pour prendre un congé temporaire de la vie qu’il mène que pour examiner les raisons de sa détresse quotidienne. Le monologue intérieur se transforme rapidement en dialogue, dès lors qu’un double vindicatif, interrompant la voix principale par des « répliques » entre parenthèses, fait son apparition. Une relation houleuse – sous tension – se tisse entre ces deux facettes du personnage tout au long des sept jours de la réclusion, les passages de dispute alternant avec des récits de souvenirs. En somme, le roman tente de dramatiser la question de l’emprisonnement de soi-même et de la limitation de l’écriture, cette limitation pouvant être à la fois malsaine et libératrice. Quant à l’essai, Tensions et enfermement dans les Cent Vingt Journées de Sodome du marquis de Sade, il part du thème de l’enfermement (en l’occurrence, celui des quatre amis qui exécutent le projet de passer quatre mois dans un château isolé) pour postuler une « architecture du désir » dans Les Cent Vingt Journées de Sodome. L’essai mobilise les ressources de la narratologie en prenant en compte les effets du texte sur le lecteur ; sont ainsi mises en évidence les tensions – sexuelle pour les protagonistes, narrative pour le lecteur – élaborées par cette écriture de l’enfermement et de la contrainte, dans laquelle le désir est toujours maintenu mais rarement satisfait. / This M.A. thesis combining research and creative writing globally focuses on self-confinement and the various tensions that it creates. La Parenthèse, a novel in the form of a diary, depicts a young man who decides to confine himself in his apartment for a week without any contact with the outside world, taking a break of his life in order to question himself about his daily angst. The inner monologue changes quickly into a dialogue, as soon as a vindictive alter ego begins to interrupt the main voice with “repartees” in parenthesis. A stormy – tense – relationship builds itself between these two sides of the character throughout the seven days he stays locked indoors, passages of arguments alternating with recollections of memories. In short, the novel proposes a reflection about self-confinement and constrained writing, which is both unwholesome and liberatory. As for the essay, Tensions et enfermement dans Les Cent Vingt Journées de Sodome du marquis de Sade, it takes us from self-confinement (namely, the four friends deciding to confine themselves for four months in a distant castle) to an “architecture of desire” in Les Cent Vingt Journées de Sodome. The essay is based on narratology without neglecting the effects the text has on its reader to bring out the tensions – sexual ones regarding the protagonists, narrative ones regarding the reader – elaborated by Sade’s confinement writing, which unfolds a desire much celebrated but seldom fulfilled.