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Computational Fluid Dynamics (CFD) Evaluation of Non-planar Stent Graft Configurations in Endovascular Aneurysm Repair (EVAR)Shek, Lok Ting 20 December 2011 (has links)
Crossing of stent graft limbs during endovascular aneurysm repair (EVAR) is often used to assist cannulation and prevent graft kinking when the aortic bifurcation is widely splayed. Little has been reported about the implications of cross-limb EVAR, especially in comparison to conventional EVAR. Using computational fluid dynamics, this work numerically examines the hemodynamic differences between these two out-of-plane stent graft configurations against a planar configuration commonly found in literature. Predicted values of displacement force, wall shear stress, and oscillatory shear index were similar between the out-of-plane configurations. The planar configuration predicted similar wall shear stress values, but significantly lower displacement forces than the out-of-plane configurations. These results suggest that the hemodynamic safety of cross-limb EVAR is comparable to conventional EVAR. However, a study of clinical outcomes may reveal reduced thrombosis incidence and long-term structural implications for the stent graft in cross-limb EVAR.
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Computational Fluid Dynamics (CFD) Evaluation of Non-planar Stent Graft Configurations in Endovascular Aneurysm Repair (EVAR)Shek, Lok Ting 20 December 2011 (has links)
Crossing of stent graft limbs during endovascular aneurysm repair (EVAR) is often used to assist cannulation and prevent graft kinking when the aortic bifurcation is widely splayed. Little has been reported about the implications of cross-limb EVAR, especially in comparison to conventional EVAR. Using computational fluid dynamics, this work numerically examines the hemodynamic differences between these two out-of-plane stent graft configurations against a planar configuration commonly found in literature. Predicted values of displacement force, wall shear stress, and oscillatory shear index were similar between the out-of-plane configurations. The planar configuration predicted similar wall shear stress values, but significantly lower displacement forces than the out-of-plane configurations. These results suggest that the hemodynamic safety of cross-limb EVAR is comparable to conventional EVAR. However, a study of clinical outcomes may reveal reduced thrombosis incidence and long-term structural implications for the stent graft in cross-limb EVAR.
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Study on Zero-Crossing-Based ADCs for Smart Dust ApplicationsKhan, Shehryar, Awan, Muhammad Asfandyar January 2011 (has links)
The smart dust concept is a fairly recent phenomenon to engineering. It assumes monitoring of a real natural environment in which motes or smart dust machines swarm in collective and coordinate information among themselves and/or to a backend control platform. In analog mixed signal field work on such devices is gaining momentum such that it is conceived to be one of the emerging fields in technology, and work was only possible once the technology for fabrication touched the nanoscale regions. Smart dust network involves remote devices connected in a hive sensing burst type datum signals from the environment and relaying information amongst themselves in an energy efficient manner to coordinate an appropriate response to a detected stimulus. The project presumed a RF based communication strategy for coordination amongst the devices through a wireless medium. That is less susceptible to stringent requirements of LOS and a base band processing system that comprised of an environment sensor, an AFE module, an ADC, a DSP and a DAC. Essentially a 10 bit, 2 Mega Hertz MHz pipelined ADC implemented in a STM 65nm technology. The ADC benefits the smart dust device in allowing it to process data in an energy efficient way and also focusing on reduced complexity as itsdesign feature. While it differs in the other ADC of the system by operating at a higher frequency and assuming a different design philosophy assuming a coherent system sensitive to a clock. The thesis work assumes that various features ofenergy harvesting, regulation and power management present in the smart dustmote would enable the system to contain such a diverse ADC. The ADCs output digital datum would be compatible to the rest of the design modules consisting mainly of DSP sections. The ADC novelty is based on the fact that it removes the necessity of employing a high power consuming OpAmp whose design parameters become more complex as technology scales to the nanoscale era and further down. A systematic, bottom up, test driven approach to design is utilized and various behaviours of the system are captured in Cadence design environment with verilogto layout models and MATLAB and Simulink models.
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An Evaluation of a Parent Implemented In- Situ Pedestrian Safety Skills Intervention for Individuals with AutismHarriage, Bethany Ann 01 January 2013 (has links)
This study evaluated a parent implemented in-situ pedestrian safety skills intervention for three individuals with autism. Specifically, this study examined the utility of using a behavioral skills training (BST) to help parents implement the most-to-least prompting procedures in training their children with autism pedestrian safety skills in community settings. A multiple baseline design across participants was used to assess parent implementation of in-situ pedestrian training as well as child participants' independently performed correct skills. Results indicated that parents implemented most-to-least prompting procedures with high levels of accuracy across streets during intervention and fading of BST. All child participants improved their safety skills significantly during intervention. For one child, the acquired skills maintained during follow- up. The percentages of their independent correct use of pedestrian safety skills were similar to those in baseline during generalization probes.
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Effectiveness of Elevated Skid Trail Headwater Stream Crossings in the Cumberland PlateauReeves, Christopher D. 01 January 2012 (has links)
One of the primary concerns associated with timber harvesting is the production of sediments from stream crossings. While research has shown that using improved haul road crossings can mitigate sediment production in perennial streams compared to the use of unimproved crossings little research has been undertaken on temporary skidder crossings of headwater streams, a situation common to a significant percentage of ground skidding operations. This experiment consisted of a controlled replicated testing of the effectiveness of four types of temporary skidder stream crossings (unimproved ford, corrugated culvert, wood panel skidder bridge, and PVC pipe bundle) relative to bedload and suspended sediment production. Automated samplers were used to monitor sediment and bedload production during the construction, use, removal, and post-removal phases associated with the use of these temporary crossings. Results showed that elevated crossings mitigated total sediment production compared to unimproved fords. Further, wood panel bridges yielded lower amounts of sediment than culverts but PVC pipe bundles show no difference between bridges or culverts. Sediment production varied by crossing type and use phase. While no differences were found among crossings types during construction, there was a difference between improved crossings and fords during use. Further, bridges and PVC pipe bundle crossings produced significantly less sediments than culverts during both their removal and during post-removal sampling and fords produced the largest amount of sediments during these phases.
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Prediction Model to Estimate the Zero Crossing Point for Faulted WaveformsHossan, Md. Shakawat 01 January 2014 (has links)
In any power system, fault means abnormal flow of current. Insulation breakdown is the cause of fault generation. Different factors can cause the breakdown: Wires drifting together in the wind, Lightning ionizing air, wires with contacts of animals and plants, Salt spray or pollution on insulators. The common type of faults on a three phase system are single line-to-ground (SLG), Line-to-line faults (LL), double line-to-ground (DLG) faults, and balanced three phase faults. And these faults can be symmetrical (balanced) or Unsymmetrical (imbalanced).In this Study, a technique to predict the zero crossing point has been discussed and simulated. Zero crossing point prediction for reliable transmission and distribution plays a significant role. Electrical power control switching works in zero crossing point when a fault occurs. The precision of measuring zero crossing point for syncing power system control and instrumentation requires a thoughtful approach to minimize noise and external signals from the corrupted waveforms A faulted current waveform with estimated faulted phase/s, the technique is capable of identifying the time of zero crossing point. Proper Simulation has been organized on MATLAB R2012a.
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Langue, espace et (re)composition identitaire dans les oeuvres de Mehdi Charef, Tony Gatlif et Farid Boudjellal / Language, space and identity (re)construction in the works of Mehdi Charef, Tony Gatlif and Farid BoudjellalMielusel, Ramona 19 June 2014 (has links)
My dissertation critically assesses the evolution of Beur productions (1980s - 21st century) with reference to the socio-cultural and economic conditions of their development. I am interested in identity (re)construction in the work of three Algerian origin artists in France: Mehdi Charef, Tony Gatlif and Farid Boudjellal. I examine texts and films like Le thé au Harem d’Archi Ahmed (1983), Petit Polio (1999), Je suis né d’une cigogne (1999) and Exils (2004). My interest lies in analyzing the impact that these “minor” artists and their chosen art genres have on mainstream cultural productions.
Besides focusing on the second generation immigrants in France (the Beurs), the authors challenge also the canonical “Frenchness” or “Europeanness” beyond borders, thus promoting the concept of cultural hybridity. I argue that constant displacement, change of political, social and cultural contexts have significantly transformed the dynamics between the center and the periphery. Furthermore, I provide evidence that “French” identity has undergone a continuous transformation over time and has become a substantially diverse and lively construct. I stand for a new approach to the fixed French identities, one that includes a pluriethnic and multilingual francophone body, and for a redefinition of cultural boundaries reshaping the relationship between self and otherness.
My thesis has two major sections (language and space) divided respectively into four chapters. The first two chapters look at different ways in which the Franco-Maghrebi literature and cinema forge new ways of expression within French language and culture. The first chapter is mainly focused on the importance of mastering French by the Beur artists, while in the second chapter I insist on more elaborate stylistic dimensions such as postcolonial irony in the given texts. The last two chapters critically analyze how the artistic productions of Charef, Gatlif and Boudjellal situate themselves in the French socio-cultural context by trespassing borders of a cultural, literary, linguistic and geographical order. This multiple border crossing leads to a movement of these texts to different locations within the main culture. At the esthetic level, this movement between different borders promotes the innovation and the creativity that the Beur artists bring to France.
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Langue, espace et (re)composition identitaire dans les oeuvres de Mehdi Charef, Tony Gatlif et Farid Boudjellal / Language, space and identity (re)construction in the works of Mehdi Charef, Tony Gatlif and Farid BoudjellalMielusel, Ramona 19 June 2014 (has links)
My dissertation critically assesses the evolution of Beur productions (1980s - 21st century) with reference to the socio-cultural and economic conditions of their development. I am interested in identity (re)construction in the work of three Algerian origin artists in France: Mehdi Charef, Tony Gatlif and Farid Boudjellal. I examine texts and films like Le thé au Harem d’Archi Ahmed (1983), Petit Polio (1999), Je suis né d’une cigogne (1999) and Exils (2004). My interest lies in analyzing the impact that these “minor” artists and their chosen art genres have on mainstream cultural productions.
Besides focusing on the second generation immigrants in France (the Beurs), the authors challenge also the canonical “Frenchness” or “Europeanness” beyond borders, thus promoting the concept of cultural hybridity. I argue that constant displacement, change of political, social and cultural contexts have significantly transformed the dynamics between the center and the periphery. Furthermore, I provide evidence that “French” identity has undergone a continuous transformation over time and has become a substantially diverse and lively construct. I stand for a new approach to the fixed French identities, one that includes a pluriethnic and multilingual francophone body, and for a redefinition of cultural boundaries reshaping the relationship between self and otherness.
My thesis has two major sections (language and space) divided respectively into four chapters. The first two chapters look at different ways in which the Franco-Maghrebi literature and cinema forge new ways of expression within French language and culture. The first chapter is mainly focused on the importance of mastering French by the Beur artists, while in the second chapter I insist on more elaborate stylistic dimensions such as postcolonial irony in the given texts. The last two chapters critically analyze how the artistic productions of Charef, Gatlif and Boudjellal situate themselves in the French socio-cultural context by trespassing borders of a cultural, literary, linguistic and geographical order. This multiple border crossing leads to a movement of these texts to different locations within the main culture. At the esthetic level, this movement between different borders promotes the innovation and the creativity that the Beur artists bring to France.
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Bouquet formation, rapid prophase movements and homologous pairing during meiotic prophase in Saccharomyces cerevisiaeLee, Chih-ying. January 2009 (has links) (PDF)
Thesis (Ph. D.)--University of Oklahoma. / Bibliography: leaves 139-152.
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L’art à Chypre de 1974 à 2014 : de l’espace fractionné au lieu symbolique / Art in Cyprus from 1974 to 2014 : from a divided space to a symbolic placeAsimenou, Monika 05 February 2015 (has links)
En 1974, l’île de Chypre s’est vue contrainte à la partition suite à une intervention militaire turque. Plus d’un tiers du territoire chypriote est encore occupé – en 2014 – par l’armée turque tandis qu’une ligne de démarcation, dite zone morte, protégée par les Casques bleus des Nations Unies, sépare les habitants de l’île entre d’un côté – au sud – les chypriotes grecs et de l’autre – au nord – les chypriotes turcs et les colons turcs.Le lieu symbolique que crée l’art à Chypre – ce territoire balafré – reproduit-il la dualité territoriale et les conséquences de la partition de l’île ? Objets de cette recherche sont les notions d’espace, de mémoire et d’histoire telles qu’elles apparaissent à travers le prisme artistique. Dans la perspective de l’histoire de l’art, cette thèse propose ainsi une analyse d’œuvres d’artistes chypriotes à travers les relations que ceux-ci entretiennent avec l’espace fractionné – le sud, le nord et la zone morte – et telles que ces relations sont révélées par les œuvres.Les créations artistiques évoquées traitent de la particularité de cet espace qui ici constitue très souvent le point de départ de la création de l’œuvre : des souvenirs du lieu perdu situé de l’autre côté de la ligne, de l’expérience de l’espace présent et de l’appropriation – concrète et métaphorique – de la zone morte. Elles mettent également en évidence la nostalgie tout en engendrant de nouvelles cartographies et en ouvrant – en vue d’une réconciliation – le champ des possibles. Chaque œuvre transgresse à sa manière – artistique, poétique et esthétique – la frontière. C’est ainsi que cet espace fractionné est susceptible de devenir « habitable ». / In 1974 the island of Cyprus was forcibly divided by a Turkish military intervention. Over a third of Cyprus' territory is still, in 2014, under occupation by the Turkish army. A demarcation line, known as the dead zone, manned by United Nations peacekeepers, separates the inhabitants of the island between on one side, the Greek Cypriots in the South, and on the other side, the Turkish Cypriots together with settlers from Turkey, in the North.Does this symbolic place that art creates, this scarred territory, reproduce the territorial duality and the consequences of the division of Cyprus? The object of this research is the notions of space, memory and history as they appear through the artistic view. From the perspective of the history of art, this thesis presents an analysis of the works of Cypriot artists through the relationships they maintain with the fragmented space – the South, the North and the dead zone – as these are revealed through the works of art.The artistic creations in question deal with the particularity of this fragmented space that often constitutes the starting point of the creation of the work of art : the memories of the lost place situated on the other side of the line, the experience of the present space and the appropriation, real and metaphorical, of the dead zone. They demonstrate the nostalgia by creating new cartographies and by opening, with a view to reconciliation, the field of possibilities. Each work of art transcends in its way –artistic, poetic and aesthetic – the border. It is in this way that this fragmented space is likely to become “habitable”.
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