abstract: Microchannel heat sinks can possess heat transfer characteristics unavailable in conventional heat exchangers; such sinks offer compact solutions to otherwise intractable thermal management problems, notably in small-scale electronics cooling. Flow boiling in microchannels allows a very high heat transfer rate, but is bounded by the critical heat flux (CHF). This thesis presents a theoretical-numerical study of a method to improve the heat rejection capability of a microchannel heat sink via expansion of the channel cross-section along the flow direction. The thermodynamic quality of the refrigerant increases during flow boiling, decreasing the density of the bulk coolant as it flows. This may effect pressure fluctuations in the channels, leading to nonuniform heat transfer and local dryout in regions exceeding CHF. This undesirable phenomenon is counteracted by permitting the cross-section of the microchannel to increase along the direction of flow, allowing more volume for the vapor. Governing equations are derived from a control-volume analysis of a single heated rectangular microchannel; the cross-section is allowed to expand in width and height. The resulting differential equations are solved numerically for a variety of channel expansion profiles and numbers of channels. The refrigerant is R-134a and channel parameters are based on a physical test bed in a related experiment. Significant improvement in CHF is possible with moderate area expansion. Minimal additional manufacturing costs could yield major gains in the utility of microchannel heat sinks. An optimum expansion rate occurred in certain cases, and alterations in the channel width are, in general, more effective at improving CHF than alterations in the channel height. Modest expansion in height enables small width expansions to be very effective. / Dissertation/Thesis / M.S. Mechanical Engineering 2011

O principal objetivo deste trabalho é prever a evolução de margens divergentes desde o início da extensão litosférica, levando-se em consideração a interação entre processos superficiais e tectônicos. Para isto, foi desenvolvido um modelo numérico que acopla isostasia flexural, efeitos térmicos, estiramento litosférico e processos superficiais. A isostasia flexural é simulada através de uma placa elástica fina sobre um fluido invíscido, representando o comportamento flexural da litosfera flutuando sobre a astenosfera. Durante a simulação, a estrutura térmica da litosfera evolui como um resultado da advecção e difusão do calor no interior da Terra. Considera-se que o estiramento da litosfera é acomodado por falhas planas na crosta superior e deformação dúctil na crosta inferior e manto. O modelo de processos superficiais descreve como a paisagem é erodida e como os sedimentos são transportados e depositados nas bacias sedimentares. Através desse modelo numérico, é mostrado que o estiramento litosférico tem uma profunda influência na evolução da migração de escarpas em margens divergentes. Os resultados sugerem que escarpas limitadas por falhas criadas em flancos de rifts por descarregamento mecânico e resposta flexural têm pouca chance de \"sobreviver\" através de recuo erosivo se a crosta inferior sob o flanco do rift foi substancialmente estirada. Nessa configuração, o divisor de drenagem que persiste através do tempo é criado em direção ao continente em uma posição que depende da rigidez flexural da crosta superior. Esse cenário ocorre quando a topografia pré-rift mergulha para o continente, caso contrário a evolução da escarpa é guiada pelo divisor de águas interior pré-existente. Esses conceitos são aplicados no estudo das margens do sudeste da Australia e do sudeste do Brasil, onde o cenário de retração de escarpas através de recuo erosivo mostrou-se improvável. O mesmo modelo numérico foi utilizado para estudar como a passagem de uma anomalia térmica sob a litosfera pode afetar a evolução pós-rift de bacias sedimentares em margens divergentes. Os resultados numéricos mostram que a velocidade da litosfera em relação à anomalia térmica e a rigidez flexural da litosfera oceânica e continental afetam a evolução de bacias sedimentares devido ao soerguimento da superfície relacionado com a expansão térmica da litosfera. Como exemplo, é estudada a possível influência de uma anomalia térmica (Pluma de Trindade?) na evolução das bacias de Campos e Espírito Santo, na margem sudeste brasileira. / The purpose of this work is to predict the evolution of divergent margins since the onset of lithospheric extension, taking into account the interaction between surface and tectonic processes. For this, a numerical model was developed to study the coupling of flexural isostasy, thermal effects, stretching of the lithosphere and surface processes. The flexural isostasy is simulated through a thin elastic plate overlying an inviscid fluid, representing the flexural behavior of the lithosphere floating on the asthenosphere. During the simulation, the thermal structure of the lithosphere evolves as a result of advection and diffusion of heat in the Earths interior. The stretching of the lithosphere is assumed to be accommodated by planar faults in the upper crust and ductile flow in the lower crust and mantle. The surface processes model describes how the landscape is eroded and how the sediments are transported and deposited in the sedimentary basins. The results from this numerical model show that the amount of lithospheric stretching has a profound influence on the evolution of escarpment migration in divergent margins. These results suggest that fault-bounded escarpments created at rift flanks by mechanical unloading and flexural rebound have little potential to survive as retreating escarpments if the lower crust under the rift flank is substantially stretched. In this configuration, a drainage divide that persists through time is created landward in a position that depends on the flexural rigidity of the upper crust. This scenario occurs when the pre-rift topography dips landward, otherwise the evolution of the escarpment is guided by the pre-existing inland drainage divide. These concepts are applied to study the margins of Southeastern Australia and Southeastern Brazil, where the retreating escarpment scenario showed to be unlikely. The same numerical model is used to study how the passage of a thermal anomaly under the lithosphere can affect the post-rift evolution of sedimentary basins in divergent margins. The numerical results show that the velocity of the lithosphere relative to the thermal anomaly and the flexural rigidity of the continental and oceanic lithospheres affect the evolution of sedimentary basins due to surface uplift related to thermal expansion of the lithosphere. As an example, the model is applied to assess the possible influence of a thermal anomaly (Trindade Plume?) on the evolution of the Campos and Esp rito Santo Basins, in Southeastern Brazilian margin.

Cette thèse développe de nouvelles séquences réactionnelles divergentes vers les lactones sesquiterpéniques, ainsi que leurs analogues. La réactivité multiple d’un substrat linéaire face à divers catalyseurs a tout d’abord permis d’obtenir différentes structures polycyliques dont la fonctionnalisation a permis d’isoler plusieurs produits naturels et des analogues. De nouvelles méthodologies ont été étudiées pour accéder aux gamma-butyrolactones, une fonctionnalité prépondérante dans les lactones sesquiterpéniques, ainsi qu’au noyau hydroazulène contenu dans les guaianes. Enfin, une synthèse divergente courte et performante a été mise au point pour accéder à divers analogues de la déoxyéléphantopine, un sesquiterpène aux propriétés anti-cancéreuses, afin de moduler et étudier son activité biologique. En parallèle de ces travaux sur les sesquiterpènes, une autre chimie a été explorée visant à réaliser la glycosylation de cystéines avec des carbohydrates non protégés. / The main thread throughout this thesis is to develop reaction sequences that could provide facile access to the sesquiterpene lactones, or analogs thereof, using strategies that would be compatible with divergent reaction pathways. A first project harnessed the multiple reactivity mode of a linea rsubstrate to obtain different polycyclic frameworks found in sesquiterpenes whose functionalisation led to several natural products and their analogs. New methodologies were studied to access gamma-butyrolactones, a preponderant functionality in sesquiterpene lactones, and hydroazulene core, the bicyclic framework of guaianes. Finally, a short divergent pathway was designed to access diverse analogs of deoxyelephantopin, a sesquiterpene showing anti-cancer effects, so as to modulate and study its biological activity. In parallel to this work on sesquiterpenes, a different chemistry was explored aiming at performing glycosylation of cysteines with unprotected carbohydrates.

The thesis is mainly concerned with popular dystopian book series Hunger Games and Divergent. The aim of the present diploma thesis is to summarize representative characteristics of a young adult dystopian novels featuring rebellious female heroes and to closely examine the social context of the aforementioned novels. The first part of the thesis is based on the analysis of young adult dystopian novels and the attitude of young female readers to the representation of strong female protagonists in literature. The second part od this thesis presents a qualitative research realized by interviews with young female readers and it attempts to answer the research questions about the attitude of readers to examined dystopian novels and the contemporary social role of women. Keywords: dystopian novel, Hunger Games, Divergent, female protagonists, gender

In this thesis the author presents a history of non-convergent series which, in the past, played an important role in mathematics. Euler's formula, Stirling's series and Poincare's theory are examined to show the development of asymptotic series, a subdivision of divergent series.

Syftet med detta examensarbete är att få en förståelse för den didaktiska kopplingen mellan marknadsförda ”laborations-kit”/utbildningspaket, framtagna av Education Technology-företag, och det meningsskapande som dessa erbjuder. Med hjälp av syftesrelaterad textanalys, och begrepp från Lars Lindströms didaktiska läroprocesser och mer klassiska laborationsbegrepp, analyseras ”laborations-kit”/utbildningspaketens innehåll och inramning samt hur utbildningspaketen är gestaltade didaktiskt genom mål och medel. Resultatet av studien visar att den modifierade Lindström-fyrfältaren är ett användbart komplement till s.k. laborations-frihetsgrader. Tanken med ökade frihetsgrader är att succesivt ge eleven mer utmaningar. Denna tanke finns även med i Lindströms fyrfältare, men här tillkommer att ett läromål kan vara att behärska medie under kontrollerade former, dvs i teknik-världen olika instrument, apparatur, verktyg och specifika material. Med hjälp av fyrfältaren kan man som pedagog även välja att laborera ämnesfokuserat eller ämnesövergripande för att täcka andra läromål eller åstadkomma nya kreativa effekter, s.k. divergerande läromål. Det är det kreativa skapandet i kombination med behärskandet av hantverket som är det egentliga målet med laborationer och denna insikt väcks när man använder fyrfältaren. Som pedagog, vare sig man är inom skolvärlden eller på ett EdTech-företag, bör man få förståelse för vad som särskiljer de olika läroprocesserna och hur de sinsemellan kan samverka. Undersökningen har identifierat ett antal för svenskt vidkommande ”vita områden” inom teknisk-pedagogisk laborationsverksamhet, bl. a kreativa områden och ”soft skills”, alltså övningar och simulationsspel av teknikutveckling och koppling samhälle-teknik. Dessutom finns det skäl att följa utvecklingen närmaste åren inom 3D Hologram-tekniken.

京都大学 / 新制・課程博士 / 博士(理学) / 甲第22978号 / 理博第4655号 / 新制||理||1669(附属図書館) / 京都大学大学院理学研究科数学・数理解析専攻 / (主査)准教授 照井 一成, 教授 長谷川 真人, 准教授 河村 彰星 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

Studying dopamine-dependent functions such as memory and creativity can help us understand and improve quality of life in populations at risk for dopaminergic network dysfunction. I examined memory and creativity in a series of studies in different at-risk populations. The first study investigated marijuana initiation and learning in 119 inner-city youth, some with prenatal substance exposures, including to cocaine. I hypothesized that earlier-onset marijuana use would predict poorer developmental learning trajectories, and non-use the most positive. Results suggested that initiation’s effects on learning may reflect psychosocial factors rather than prenatal substance exposure status or time of marijuana initiation. The potential importance of the dopamine-related personality factor “openness to experience” motivated additional studies. One hypothesized and found different neurocognitive outcomes in young-adult substance users (n=41) based on maladaptive or adaptive substance use motives. The other studies examined Parkinson’s disease (PD), a disorder characterized by the degeneration of brain dopaminergic networks. Participants were individuals with PD without dementia (33-42 “PDs”/study), age-matched normal control adults (26-28 “NCs”/study), and younger control adults (37-41 “YCs”/study). The first PD study examined neuropsychological and personality correlates of learning and memory. I hypothesized that in each group, openness would explain a significant amount of the variance in learning, and higher openness would be associated with better learning and memory, particularly in PDs. Results supported this hypothesis in PDs only. The second PD study examined creativity—specifically, divergent thinking, which correlates with openness and shares dopaminergic neural substrates. Based on research demonstrating that brief walking improves divergent thinking in young adults, and that exercise changes dopamine transmission, I hypothesized that brief walking would improve divergent thinking in PDs, NCs, and YCs. In PDs, I expected higher disease severity (more compromised dopamine function) to correlate with less improvement after walking. None of the hypotheses were supported, potentially due to the low intensity of the intervention, but openness appeared protective of creativity in YCs and PDs. Taken together, the results of the studies demonstrate the importance of psychosocial factors in dopamine-dependent cognition. In at-risk populations, openness’s benefits may surpass effects of moderate substance use, and they may offer neuroprotection in PD.

Creativity is a complex construct that is conceptualized and measured in multiple ways. This study examined the relationship between creativity and personality taking this into account. It was hypothesized that applying different conceptions and measures would cause variation in the creativity-personality relationship. The participants (N = 224) were undergraduate students completed six creativity measures, a personality inventory, and a demographic questionnaire. Personality predicted more creative production (R2 = .277) than creative potential (R2 = .176) and more self-reported creativity (R2 = .348) than that which was externally-rated (R2 = .149). Personality predicted creativity beyond demographic and intellect variables, but the effects varied based on the creativity measure. Openness was most consistently and strongly related to creativity. Other personality factors demonstrated suppression effects in multiple models. Overall, the results suggest that despite relatively small effects of personality on creativity, it can help strengthen prediction in creativity models. Implications for educational settings and future research are discussed.

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