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PETILLI, MARCO ALESSANDRO. "Proactive Top-Down Processes in Visual Search." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2018. http://hdl.handle.net/10281/199069.
Texte intégralRésumé :
La letteratura ha indagato il ruolo dei processi top-down e bottom-up nel guidare la ricerca visiva. Recenti studi hanno suggerito un ruolo modulatorio dei processi top-down sulla cattura attentiva. Tuttavia, i risultati sono contraddittori, e il ruolo dei processi top-down non è stato ancora chiaramente stabilito.
In questo lavoro, abbiamo studiato se il controllo top-down fosse reclutato proattivamente quando c’è un’aspettativa di distrattori e abbiamo adottato il paradigma di Distraction Context Manipulation (DCM) per caratterizzare il loro reclutamento nella ricerca visiva. Pertanto, abbiamo combinato un compito di feature search e uno di conjunction search con il DCM (Esp 1-4). In linea con il DCM, i blocchi erano di tre tipi: un blocco Puro senza trial con distrattori, e due blocchi contenenti frequenti trial con distrattori (Mixed Feature e Conjunction). Il compito era individuare il target in ogni trial. Il confronto tra trial senza distrattori nei blocchi misti e nel blocco puro ha permesso di rilevare il reclutamento di processi top-down per l'aspettativa di distrattori.
Inizialmente abbiamo indagato se i processi top-down fossero reclutati nei contesti distraenti e se il loro potenziale reclutamento fosse modulato dal tipo di ricerca (Exp 1). I risultati hanno mostrato un reclutamento proattivo dei processi top-down in caso di aspettativa di distrattori sia nel feature che nel conjunction search. Tale reclutamento è emerso come costo in termini di tempo di risposta nonché come beneficio della sensibilità di detezione del target quando i distrattori erano attesi ma non presentati. Risultati sovrapponibili sono emersi nelle varianti di ricerca visiva covert (Esp 1,3) e overt (Esp 2,4).
Poiché le precedenti esperienze distraenti hanno mostrato di modellare l'aspettativa di distrattori nei trial successivi, abbiamo anche cercato di differenziare il ruolo delle aspettative da quello dell'esperienza nell'attivare i processi top-down. I risultati (Esp 1, 2 e 4) hanno indicato che il costo dovuto all’aspettativa di distrattori si verificava a prescindere che i distrattori fossero o meno presenti nel trial precedente. Tuttavia, l'entità di questo costo era maggiore dopo i trial con distrattori, suggerendo che questi processi non siano basati solo sull'aspettativa, ma siano anche rinforzati dopo un'esperienza distraente. L'esperimento 3 ha cercato di caratterizzare la natura implicita vs esplicita dei processi top-down innescati da esperienze distraenti. I risultati hanno mostrato che i costi e i benefici sui tempi di risposta non cambiano quando l'evento distraente è imprevedibile da quando è predicibile. I processi top-down innescati dalla esperienza distraente non sembrano essere soggetti al controllo esplicito. L'esperimento 4 ha ulteriormente tentato di elucidare i contributi relativi dell'esperienza e delle aspettative. Qui, anche un altro tipo di aspettativa top-down è stata manipolata: la certezza temporale che un evento potenzialmente distraente fosse in arrivo. I risultati hanno indicato un ruolo preponderante delle aspettative top-down mostrando che il costo sui tempi di risposta asseconda il decorso dell'aspettativa temporale di eventi potenzialmente distraenti mentre la prossimità temporale da una precedente esperienza distraente riveste un peso minore. Infine, l’esperimento 4 ha dimostrato che l'aspettativa dei distrattori modula i processi attenzionali. Le analisi EEG hanno indicato che l'aspettativa di distrattori aumenta l'ampiezza della componente occipitale P1 che viene elicitata sia da stimoli di ricerca che neutri, ma questo avviene solo quando viene indotta un'aspettativa temporale di un evento potenzialmente distraente.
Nel complesso, i risultati suggeriscono che sia nel feature che nel conjunction search l’attenzione è modulata in maniera proattiva per meglio affrontare le aspettative rispetto alle richieste del compito formate sulle precedenti esperienze.<br>Literature has long investigated the contributions of top-down and bottom-up processes in guiding search behavior. Recent findings suggest a modulatory role of top-down processes on attentional capture. However, results are contradictory, and whether and how top-down processes intervene has not been clearly established yet.
Here, we approached the issue from the perspective of proactive top-down processes of distractor expectation and leveraged the Distractor Context Manipulation (DCM) paradigm to help characterizing their recruitment in visual search. Thus, we combined a feature search (i.e., search for a high-contrast target among no-contrast distractors) and a conjunction search (i.e., search for a high-contrast target among high-contrast distractors) with the DCM paradigm (Exp 1-4). Accordingly, blocks of trials were of three types: a Pure block containing no distractor-present trials, and two blocks containing frequent distractor-present trials (i.e., Mixed Feature and Mixed Conjunction). Subjects were instructed to look for the target on each trial. The comparison of distractor-absent trials of Mixed vs Pure blocks allowed detecting proactive top-down processes of distractor expectation. First, we investigated whether proactive top-down processes were recruited in distracting contexts of visual search and whether their potential recruitment was modulated by the type of search (Exp 1). Results attested for a proactive recruitment of top-down processes of distractor expectation in both feature and conjunction search. Such recruitment entailed a response time (RT) cost as well as a beneficial enhancement of the detection sensitivity (d’) to the target when distractors were expected, yet not presented. Overlapping results emerged in covert (Exp 1, 3) and overt (Exp 2, 4) variants of visual search. Since previous distracting experience shaped distractor expectation, we, also, sought to disentangle the role of expectation and experience in the activation of top-down processes. Results (Exp 2, 4) showed that the distractor expectation cost occurred regardless of whether or not distractors occurred in the immediately preceding trial. However, the magnitude of the cost was larger after distracting trials suggesting that these processes do not rely only on tonic expectation-based mechanisms but they are also contingently reinstated after a distracting experience occurred. Experiment 3 tried to characterize the implicit vs explicit nature of top-down mechanisms triggered by distracting experience. Results showed that RT-costs and d'-benefits did not change when distraction occurrence was unpredictable and when it was predictable. Therefore, top-down control setting triggered by recent distracting experience seems to be not subjected to explicit control. Experiment 4 further investigated the role of experience and expectations in order to disentangle their relative contributions. Here, also another type of top-down expectation was manipulated: the temporal certainty of incoming potentially distracting event. Results indicated a preponderant role of top-down expectations by showing that RT-costs followed the time course of temporal expectation of incoming potentially distracting events while temporal recency from a previous distracting experience had a smaller weight. Finally, Experiment 4 explored the EEG correlates of distractor expectation. An enhancement of the occipital P1 amplitude was elicited by both search and neutral stimuli but only when a temporal expectation of a potentially distracting event was induced indicating that distractor expectation modulates visual attentional processes in lower sensory areas.
Overall, results suggested that in both feature and conjunction search preparatory top-down processes are proactively enrolled to face with expected task demands based on previous distracting experiences. These results help characterizing how top-down mechanisms intervene in different types of visual search.
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Silva, Tainá Gouvêa Galvão. "Integração das estratégias de sustentabilidade: \"top-down\" e \"bottomup\" como ferramentas de aprendizagem para a alfabetização ecológica no Ensino Médio." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/97/97138/tde-04122018-145828/.
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O desenvolvimento sustentável no final do século XX surgiu para expressar preocupações com graves problemas que causam riscos a vida no planeta. O uso do planeta de forma sustentável exigirá diferentes estratégias de sustentabilidade. Neste sentido têm-se as estratégias que abordam o nível mais elevado do ecossistema referidas como Top-down e as estratégias que abordam componentes locais ou regionais referidas como bottom-up. A escola traz essa compreensão nos conceitos e fenômenos ecológicos. No entanto, a compreensão dessas abordagens com apoio interdisciplinar faz com que o aluno entenda os fenômenos ecológicos de forma mais crítica. Assim, para um aprendizado motivador, o professor pode utilizar como recurso didático além dos espaços formais de educação também espaços não formais de educação, ou seja, aulas de campo em ambientes naturais. Com o intuito de promover no ensino de ecologia a alfabetização ecológica dos alunos no Ensino Médio, este trabalho elaborou uma proposta didática com apoio interdisciplinar (Biologia, Língua Portuguesa e Geografia) e com ênfase nas estratégias Top-down e bottom-up abordadas tanto em espaços formais quanto não formais de educação. O método de ensino em espaço formal de educação apesar de estar estruturado didaticamente para abranger a ecologia não se apresentou motivadora ao aluno e muitos dos conceitos e fenômenos ecológicos não foram assimilados por eles. Em contrapartida, a integração interdisciplinar em associação com as estratégias de Top-down e bottom-up em espaços não formais de educação foi motivadora para o aluno melhorando o seu desempenho com relação à assimilação dos conceitos e fenômenos biológicos promovendo a alfabetização ecológica dos alunos. Espera-se com esse trabalho ter contribuído para o ensino e aprendizagem do tema sustentabilidade através da promoção da alfabetização ecológica dos alunos de Biologia no Ensino Médio em escolas públicas com a formação de cidadãos mais conscientes e críticos em assuntos ambientais.<br>Sustainable development in the late 20th century has emerged to express concerns about serious life-threatening problems on the planet. The use of the planet in a sustainable way will require different sustainability strategies. In this sense we have the strategies that approach the highest level of the ecosystem referred to as \"top-down\" and the strategies that approach local or regional components referred to as \"bottom-up\". The school brings this understanding into concepts and ecological phenomena. However, understanding these approaches with interdisciplinary support makes the student understand ecological phenomena more critically. Thus, for a motivating learning, the teacher can use as a didactic resource beyond the formal spaces of education also non-formal spaces of education, that is, field lessons in natural environments. In order to promote ecological literacy among students in high school, this work elaborated a didactic proposal with interdisciplinary support (Biology, Portuguese Language and Geography) and with emphasis on top-down and bottom-up strategies addressed in both formal and non-formal education settings. The method of teaching in formal educational space despite being structured to cover ecology did not present itself as motivating to the student and many concepts and ecological phenomena were not assimilated by them. In contrast, interdisciplinary integration in association with top-down and bottom-up strategies in non-formal education spaces was motivating for the student to improve his performance in relation to the assimilation of concepts and biological phenomena by promoting literacy of the students. It is hoped that this work contributed to the teaching and learning of the sustainability theme through the promotion of the ecological literacy of Biology students in High School in public schools with the formation of citizens more conscious and critical in environmental issues.
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Wood, James David Gordon. "How are systems of bottom-up consent manufactured in financialised capitalism? : British and Danish residential capitalisms compared." Thesis, King's College London (University of London), 2017. https://kclpure.kcl.ac.uk/portal/en/theses/how-are-systems-of-bottomup-consent-manufactured-in-financialised-capitalism(a0e68227-7e06-496e-9db7-055ebf428508).html.
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This research project examines why systems of mortgage finance in Britain and Denmark have largely been immune to substantive reform, despite the failures and costs manifested by the 2008 global financial crisis. Neo-Weberian scholars currently dominate this research area, and suggest deregulated mortgage markets are maintained to facilitate access to the social norm and material gains of private housing to foster bottom-up consent to political party rule. However, whether private housing is an independent social norm is highly questionable, and the financial gains from homeownership are highly stratified. Additionally, the emphasis on the home as a financial asset fails to account for the decline in wages as a share of GDP, which is negatively affected by the process of financialisation. This thesis deploys a quantitative analysis to assess whether there is any meaningful relationship between the falling wage share and the vast expansion of mortgage credit, and a qualitative examination of whether there is a deliberate social purpose encoded in public policy formulation to meet such ends. The results from the time-series regression analysis demonstrated that the increased distribution of mortgage credit does have a negative effect on the wage share in Britain between 1979 and 2012, but not in Denmark. The qualitative analysis of the British case demonstrated that mortgage credit was deregulated to establish a mortgage-led financialised accumulation regime that increased the capital share of GDP at the expense of wages. Additionally, the disciplinary mechanisms of mortgage credit were used to integrate deviant trade union members into a functioning social formation. Alternatively, the qualitative analysis of the Danish case revealed how mortgage finance has been restricted and liberalised to regulate the performance of the macro-economy. The Danish government uses mortgage credit to intervene in the economy as the country’s integration into the European and global economy have marginalised their ability to use traditional fiscal and monetary policy interventions. A comparative analysis of British and Danish mortgage systems connected them to the wider political economy of each state, specifically welfare state structures and industrial relations, which explains the necessity of maintaining liberalised mortgage finance markets in Britain and Denmark.
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Jachim, Stephen. "Investigating the balance of bottom-up and top-down processing in autistic perception." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/investigating-the-balance-of-bottomup-and-topdown-processing-in-autistic-perception(e6b4935d-2599-40b1-b0e1-003f7d636500).html.
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Autism spectrum disorder (ASD) is a neurodevelopmental disorder emerging in the first few years of life. Currently, three characteristics are required for a diagnosis of ASD, impaired social interactions, impaired verbal communication and restricted and repetitive patterns of behaviour or interests. This last category can optionally include hyper- or hypo-reactivity to sensory input. Individuals with autism can also display superior performance on visual tasks where it may help to ignore global detail, behaviour sometimes described as ‘not seeing the forest for the trees’. At present, the exact mechanisms underlying the perceptual differences between autistic and neurotypical groups remain unknown, but they may reflect an imbalance in the contributions that bottom-up and top-down processing make in perceptual processing. Visual perception is thought to rely on interactions between the ‘bottom-up’ flow of ambiguous information from the retina and the ‘top-down’ flow of disambiguating information from higher cortical areas, via cortical circuits that have been shaped by a lifetime’s experience. These interactions lead to the activation of internal representations (of objects) which are necessary for the successful navigation of our environment. In order to investigate these perceptual differences, we employed three well-known experimental paradigms with a group of thirteen autistic participants and their matched controls. We investigated visual integration (involving bottom-up and top-down interactions) across low and intermediate stage neural mechanisms. A dim line (target) is easier to detect when flanked by two brighter collinear lines (flankers), an effect known as collinear facilitation, and we used two variations of this task to investigate low-level visual integration. In the first, we varied the orientation of the collinear flankers and found reduced integration for an autistic compared to a neurotypical group, a finding that conflicts with previous research. In a second collinear facilitation experiment with neurotypical participants, in which the target could be presented before, during or after flanker presentation, we were able to isolate facilitation that we believe was due to feedforward and feedback processing. However, in a subsequent study in which we compared autistic and neurotypical performance on this task, we found no significant difference. Moving onto intermediate level visual integration, we used a contour integration task consisting of open (lines) and closed (square) contours and found reduced integration for the autistic compared to the neurotypical groups when integrating closed contours. In our final study, we looked at global motion integration, and made use of a translating diamond. This is a bistable stimulus in which four lines can be perceived as independent line fragments moving vertically, or as a single integrated shape - a diamond moving horizontally. In this experiment, the autistic group showed an unexpected bias to perceiving the stimuli in its integrated form as a diamond. Perceptual processing of shapes based on squares or diamonds reflects visual integration at a global level, and so the differences we have found in shape processing between our experimental groups (reduced integration for the square and increased integration for the diamond in autism) are more likely to be the result of differences in top-down processing.
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Donchatz, Joanna Marie. "Kettle Bottom." Kent State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=kent1334950609.
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Watson, Graham Redpath. "Flow patterns in flat-bottomed silos." Thesis, University of Edinburgh, 1993. http://hdl.handle.net/1842/14649.
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The work in this thesis is directed towards the measurement and prediction of the shape of the flow channel in granular solids as they discharge from flat-bottomed silos. It is widely believed that the flow pattern affects the pressure distribution against the walls and so also the stresses in the silo structure. Thus, a reliable means of predicting the shape of the flow channel has important design implications. Kinematic analysis is used as the basis for the theoretical work. The governing partial differential equation contains one unknown empirical parameter: the kinematic parameter. Finite element formulations are developed and implemented to solve for the steady-state vertical velocity field in flowing granular solids for a range of conjectured kinematic parameters. The formulations are applied to the analysis of flow from flat-bottomed silos with planar or axisymmetric geometries. Criteria are proposed to define the boundary between flowing and near-stationary solid. The flexibility of the finite element method allows many original kinematic analyses to be carried out <i>e.g</i> the analysis of silos with more than one outlet; the analysis of planar silos with eccentrically-positioned orifices; the analysis of the effect of a spatially-varying kinematic parameter and the modelling of the top surface displacement are all claimed to be original. Experiments are carried out in a half-cylindrical flat-bottomed silo. A rigid transparent sheet is used to form the front wall. The bisection of the flow in this way allows direct observation of flow mechanics to be made and the shape of the flow channel boundary can also be traced. Two solids are tested: a rough, frictional solid (sand) and a smooth, free-flowing solid (polypropylene pellets).
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Kruse, Megan Nicole. "Far Toward the Bottom." The University of Montana, 2010. http://etd.lib.umt.edu/theses/available/etd-05302010-152650/.
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Dougherty, Martin Eugene. "Ocean bottom seismic scattering." Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/52938.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, and Woods Hole Oceanographic Institution, 1990.<br>GRSN 589503<br>Includes bibliographical references (p. 299-301).<br>by Martin Eugene Dougherty.<br>Ph.D.
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Kootz, Andreas. "B-Identifikation im Level-2-Trigger des ATLAS-Experiments." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=97677724X.
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Killingsworth, Matthew. "Happiness from the Bottom Up." Thesis, Harvard University, 2012. http://dissertations.umi.com/gsas.harvard:10473.
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This dissertation presents three papers organized around a central theme: understanding happiness from the bottom up, in the context of everyday life. The first paper asks whether, in the course of daily activities, people need to choose between two different facets of happiness: momentary happiness and life satisfaction. Results reveal a high degree of convergence: activities associated with momentary happiness are to a large extent also associated with life satisfaction (and related constructs such as feeling that one’s life is meaningful, worthwhile, and fulfilling). Activities that one might expect to be associated mainly with a satisfying life are also associated with greater momentary happiness, and activities that one might expect to be associated mainly with greater momentary happiness are also associated with greater life satisfaction. The second paper quantifies happiness in absolute terms, revealing the percentage of life that is actually “worth living.” Existing research on happiness relies on measures of happiness that have only relative meanings. In this paper, we measure happiness by leveraging a dimension of experience that does have absolute meaning: time. We collect data on the details of people’s everyday experiences, and employ a novel method to categorize episodes of time as absolutely positive or negative. We find that roughly 40% of people’s time is experienced as negative. When we offset the positive and negative utility of these episodes we find that life is a net positive, but only moderately so. The third paper examines the relationship between happiness and a particular domain of everyday experience: mind-wandering. Participants report mind wandering (i.e., engaging in task-unrelated thought) nearly half the time, but are less happy when doing so. Moreover, timelag analyses find that unhappiness tends to follow rather than precede mind-wandering, suggesting that mind-wandering causes unhappiness rather than the other way around. Interestingly, the variance in happiness explained by mind-wandering is largely non-overlapping with variance explained by people’s activities. This suggests that what people do (their activities) and think (whether and where their minds wander) may be two independent determinants of happiness.<br>Psychology
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Chapman, Genesis. "Bottom Creek, Bent Mountain, VA." VCU Scholars Compass, 2010. http://scholarscompass.vcu.edu/etd/2163.
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The title of this thesis Bottom Creek, Bent Mountain, VA is the subject of my large ink drawings. Starting with the spring outside my window, this book describes the creeks as it flows across the mountain that I grew up on. My drawings document the experience of walking along the banks of Bottom Creek as it flows past farms fields and along the roadside. Described as a seemingly insignificant place, the creek is in fact it is one of the most basic, and important parts of this mountain’s landscape, because the creek’s natural process it is responsible for producing the landscape as we see it. Through drawing the water from direct observation, I find a deeper connection to the land and respect for its ever changing processes.
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Kingdon, Lorraine B. "The Bottom Line is Pride." College of Agriculture, University of Arizona (Tucson, AZ), 1987. http://hdl.handle.net/10150/295554.
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McCoy, Jan. "The Bottom Line on Trees." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/295664.
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Savory, P. G. "Interpretation of sub-bottom signals." Thesis, University of Bath, 1986. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370997.
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Howell, Henry R. G. "Inferring bottom acoustic properties from AN /." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2000. http://handle.dtic.mil/100.2/ADA384490.
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Thesis (M.S. in Physical Oceanography) Naval Postgraduate School, Sept. 2000.<br>"September 2000." Thesis advisor(s): Bourke, Robert H.; Wilson, James H. Includes bibliographical references (p. 89-92). Also available online.
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Allet, Marion. "Microfinance and the environmental bottom line." Doctoral thesis, Universite Libre de Bruxelles, 2013. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209516.
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Microfinance has strongly developed over the past decades on the promise of reaching a double bottom line of financial viability and social impact. Recently, some actors have started to advocate that microfinance, to be truly responsible, should include a third environmental objective as well. However, little scientific knowledge exists today on environmental management within microfinance institutions (MFIs). The objective of this PhD thesis is to shed light on how MFIs manage their environmental bottom line. More specifically, we identify the strategies adopted by MFIs to improve their environmental bottom line, we propose a new framework to assess the environmental performance of MFIs, and we analyze their motives for going green, the characteristics of MFIs involved in environmental management, and the challenges that they face when implementing environmental programs./La microfinance s’est fortement développée ces dernières années sur la base d’une double promesse :celle d’atteindre une viabilité financière tout en ayant un impact social. Récemment, certains acteurs ont commencé à déclarer que la microfinance, afin d’être véritablement responsable, devrait inclure un troisième objectif, environnemental. Aujourd’hui, les connaissances scientifiques liées à la gestion environnementale au sein des institutions de microfinance (IMF) sont toutefois limitées. Cette thèse s’intéresse donc à la manière dont les IMF gèrent leur impact environnemental. Plus particulièrement, elle identifie les stratégies adoptées par les IMF pour améliorer leur performance environnementale, propose un outil de mesure de la performance environnementale des IMF, et analyse leurs motivations pour devenir vertes, les caractéristiques des IMF engagées dans la gestion environnementale, et les défis auxquels elles sont confrontées lors de la mise en œuvre de programmes environnementaux.<br>Doctorat en Sciences économiques et de gestion<br>info:eu-repo/semantics/nonPublished
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Mellor, D. J. "A measurement of bottom hadron lifetimes." Thesis, University of Oxford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376930.
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Jones, Trevor N. "Ocean bottom modeling for ray acoustics." Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/26660.
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Robertson, Candace Joanne. "Ocean bottom simulation using fractal geometry." Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/26661.
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LaCasce, Joseph H. 1964. "Baroclinic vortices over a sloping bottom." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/54422.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1996.<br>Includes bibliographical references (p. 212-220).<br>by Joseph H. LaCasce, Jr.<br>Ph.D.
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Frank, Donya P. "Wave-Current Bottom Boundary Layer Interactions." The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1229087949.
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Munoz, Genevieve Ann. "Emotional branding Obama's bottom-up campaign /." Click here to view, 2009. http://digitalcommons.calpoly.edu/comssp/6/.
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Thesis (B.A.)--California Polytechnic State University, 2009.<br>Project advisor: Bernard Duffy. Title from PDF title page; viewed on Mar. 11, 2010. Includes bibliographical references. Also available on microfiche.
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Ba, Ndeye Baty. "Phyllis Bottome : essai d'interprétation d'un univers romanesque adlérien." Caen, 1985. http://www.theses.fr/1985CAEN1014.
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Plymell, Kendra K. "The commercialization of microfinance in Latin America and the Caribbean bottom of the pyramid or bottom line?" View electronic thesis, 2008. http://dl.uncw.edu/etd/2008-3/rp/plymellk/kendraplymell.pdf.
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Gontz, Allen M. "Evolution of Seabed Pockmarks in Penobscot Bay, Maine." Fogler Library, University of Maine, 2002. http://www.library.umaine.edu/theses/pdf/GontzAM2002.pdf.
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Vititoe, David Lee 1970. "Measurement of the inclusive bottom quark production cross section and bottom anti-bottom azimuthal angle correlations in proton anti-proton collisions at center-of-mass energy = 1.8 TeV." Diss., The University of Arizona, 1997. http://hdl.handle.net/10150/282323.
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Using dimuon events produced in proton-antiproton collisions at √s = 1.8 TeV at the D⊘ detector, the integrated inclusive b-quark production cross section has been extracted. The inclusive b-quark production cross section for Pᵇ(T) > 9 GeV/c is 2.61 ± 0.07(Stat) ± 1.13(Syst) nb. The cross section, dσ/dΔφ(μμ) , where Δφ(μμ), is the azimuthal angle difference between the dimuons, has also been measured. Both measurements are in good agreement with next-to-leading order QCD predictions.
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Liu, Yu. "Bottom-up Engineering of Chalcogenide Thermoelectric Nanomaterials." Doctoral thesis, Universitat de Barcelona, 2018. http://hdl.handle.net/10803/663274.
Texte intégralRésumé :
In this thesis, it is detailed the bottom-up production and characterization of thermoelectric (TE) nanomaterials with significant enhanced performance by using colloidal nanocrystals (NCs) as building blocks. The production of TE nanomaterials with significant improved figure of merit (ZT), has to do, not only with the precise control of the NCs properties, but also with the further fine control over the crystallographic alignment of nanograins of highly anisotropic materials.
The first part of the thesis correspond to the study of synthetic routes to produce high quality chalcogenide NCs that are doped during the NC synthesis, in order to control the charge carrier concentration. The system studied was I−V−VI chalcogenide semiconductor, specifically it was produced the materials: AgSbSe2 and Cu3SbSe4. A low-cost, high-yield and scalable synthesis route to produce monodisperse of AgSbSe2 and Cu3SbSe4 NCs was obtained. After ligand displacement, the NCs were used as building blocks to produce TE nanomaterials. Additionally, by means of substitutional doping, a large increment in the power factor and relatively lower thermal conductivities were observed. The optimization of the doping concentration resulted in ZT values of 1.10 at 640 K for AgSb0.98Bi0.02Se2, and of 1.26 at 673 K for Cu3Sb0.88Sn0.10Bi0.02Se4, which represents a significant increase beyond the state of the art in Te-free multinary Ag/Cu-based chalcogenide materials.
In the second part of the thesis, the work about PbS-metal (Cu and Sn) nanocomposites produced by blending procedure is presented. The low work function metal is able to inject electrons to the intrinsic PbS matrix, which is another strategy to control the charge carrier concentration. The power factor is dramatically enhanced due to the increase of the electrical conductivity in the nanocomposites. Consequently, the ZTmax was remarkably enhanced by two times as compared with the pristine PbS. Furthermore, we also compared the TE performance of microcrystalline composites with the same composition as in nanocrystalline composites; commercial PbS host with Cu particles. The results revealed that with the same metal addition, higher electrical conductivities were obtained in the nanocomposite, but higher Seebeck coefficients were maintained in the microcomposite. Moreover, higher thermal conductivities were also obtained in the microcomposite. Finally, the figure of merit ZT were higher for the microcomposite system in the low temperature range, but much lower in the higher temperature range compared with the nanocomposites system.
In the last block, the process of production of crystallographically textured materials is presented. We face here the challenge of bottom-up approaches to control the crystallographic alignment of nanograins. The production of nanostructured Bi2Te3-based alloys is presented. This can be done with controlled stoichiometry by solution-processing, and crystallographic texture by liquid-phase sintering using multiple pressure and release steps at 480 °C, above the tellurium melting point. Additionally, we explain the possible mechanism to produce the highly textured nanomaterials. This strategy results in record TE figures of merit: ZT=1.83 at 420 K for Bi0.5Sb2.5Te3 and ZT=1.31 for Bi2Te2.7Se0.3 at 440 K when averaged over 5 materials in the c direction, respectively. These high figures of merit extended over a wide temperature range, which results in energy conversion efficiencies a 50% higher than commercial ingots in the similar temperature range.
In summary, different strategies to improve the TE performance of bulk nanostructured materials produced by bottom-up engineering of NCs, have been studied and confirmed in this thesis. Additionally, it has been proven that the solution-processed synthesis approach is low-cost, compatible with the scale-up engineering, and also versatile in tuning the size, shape, composition, and microstructure, among others parameters of different nanomaterials to optimize their TE properties.<br>Los nanocristales (NCs) coloidales tienen excelentes propiedades para diferentes aplicaciones, como la conversión de energía, la catálisis, los dispositivos electrónicos y optoelectrónicos, entre otros. Así mismo, la síntesis coloidal de NCs tiene ventajas en el control del tamaño, forma y composición a nivel de la nanoescala; las bajas temperaturas de reacción; y la no necesidad de equipos especializados. Este proyecto se concentra en el diseño racional y la ingeniería de materiales termoeléctricos (TE) nanoestructurados de alta eficiencia, usando la estrategia del ensamblado ascendente (bottom-up) de NCs coloidales.
Primero, se diseñó una ruta de síntesis de bajo costo, alto rendimiento, con la cual, se obtuvieron NCs de AgSbSe2 y Cu3SbSe4. La optimización de la concentración de dopaje resultó en valores para la figura de mérito TE, ZT, de 1.10 a 640 K para AgSb0.98Bi0.02Se2, y de 1.26 at 673 K para Cu3Sb0.88Sn0.10Bi0.02Se4. El material con mejores propiedades se usó para la producción de un generador TE en forma de anillo, para acoplarlo a los tubos de escape de gases, obteniendo una potencia eléctrica de 1mW por elemento TE con una diferencia de temperatura de 160 °C.
En la segunda parte, se presenta el trabajo de la producción de nanocopuestos de PbS-metal (Cu y Sn) usando un procedimiento versátil de mezcla de NCs. La función de trabajo del metal es capaz de inyectar electrones a la matriz intrínseca de PbS. El factor de potencia TE, se ve dramáticamente incrementado debido al aumento en la conductividad eléctrica en los nanocompuestos TE. Consecuentemente, el valor máximo de ZT se vio excepcionalmente incrementado por el doble del valor comparado con el material original PbS.
Finalmente, se presenta el proceso de producción de materiales texturizados cristalográficamente, produciendo materiales tipo p BixSb2-xTe3 y tipo n Bi2Te3-xSex. Se controló la estequiometria durante el procesamiento en solución y la textura cristalográfica, por medio de la sinterización en fase líquida con un procedimiento de múltiples pasos de presión y relajación a una temperatura de 480°C. Los valores de la figura de mérito TE presentan el record de: ZT=1.83 a 420 K para Bi0.5Sb2.5Te3 y ZT=1.31 para Bi2Te2.7Se0.3 a 440 K.
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Kaya, Ayse Idil. "A Study On Blended Bottom Ash Cements." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612504/index.pdf.
Texte intégralRésumé :
Cement production which is one of the most energy intensive industries plays a
significant role in emitting the greenhouse gases. Blended cement production by
supplementary cementitious materials such as fly ash, ground granulated blast
furnace slag and natural pozzolan is one of the smart approaches to decrease energy
and ecology related concerns about the production.
Fly ash has been used as a substance to produce blended cements for years, but
bottom ash, its coarser counterpart, has not been utilized due to its lower pozzolanic
properties. This thesis study aims to evaluate the laboratory performance of blended
cements, which are produced both by fly ash and bottom ash.
Fly ash and bottom ash obtained from Seyitö<br>mer Power Plant were used to produce
blended cements in 10, 20, 30 and 40% by mass as clinker replacement materials.
One ordinary portland cement and eight blended cements were produced in the
laboratory. Portland cement was ground 120 min to have a Blaine value of 3500±<br>100
cm2/g. This duration was kept constant in the production of bottom ash cements. Fly
ash cements were produced by blending of laboratory produced portland cement and
fly ash. Then, 2, 7, 28 and 90 day compressive strengths, normal consistencies,
soundness and time of settings of cements were determined.
It was found that blended fly ash and bottom ash cements gave comparable strength
results at 28 day curing age for 10% and 20% replacement. Properties of blended
cements were observed to meet the requirements specified by Turkish and American
standards.
29
Wichers, Torben [Verfasser]. "Allgemeines Bottom-Up Parsing Modell / Torben Wichers." München : Verlag Dr. Hut, 2011. http://d-nb.info/1011441861/34.
Texte intégral
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Ishihara, Yoshihiro. "DNA-inspired materials for 'bottom-up' nanotechnology." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112640.
Texte intégralRésumé :
DNA is a remarkable material that is both an inspiration for polymer nanotechnology and a versatile building block for assembling well-defined nanostructures. To create polymeric materials that would be useful in nanotechnology, we synthesized block copolymers containing thymine and diamidopyridine side chains. These DNA-mimetic polymers self-assembled into spherical aggregates in solution, held together by hydrogen bonding interactions. We have reported the first example of a block copolymer micellar aggregate that is capable of selective recognition of small-molecule guests, with concomitant changes in its aggregation behavior.<br>In the field of DNA-mediated materials, the ordering of gold nanoparticle (AuNP) arrays can be hindered by the lability of AuNP-DNA linkages. In the search of an indefinitely stable AuNP-DNA linkage, three dendritic thiol-terminated DNA strands were synthesized, and were bound to AuNPs. A preliminary AuNP-DNA linkage lability study showed potential in forming nonlabile AuNP-DNA linkages through the use of dendritic thiol-modified DNA.
31
Velasco, Sevilla Liliana Esther. "Bottom up approach to fermion family symmetries." Thesis, University of Oxford, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288519.
Texte intégral
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Wilson, Jonathan Henry. "Bottom-Up Assembly of Aqueous Nano-Suspensions." Thesis, University of Manchester, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.503051.
Texte intégral
33
Wikramanayake, Palitha Nalin. "Turbulent wave-current bottom boundary layer flows." Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/14353.
Texte intégral
34
Jenter, Harry Leonard. "Modelling bottom stress in depth-averaged flows." Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/58501.
Texte intégralRésumé :
Thesis (Ph. D.)--Joint Program in Oceanographic Engineering (Massachusetts Institute of Technology, Dept. of Civil Engineering; and the Woods Hole Oceanographic Institution), 1989.<br>Includes bibliographical references (leaves 140-145).<br>The relationship between depth-averaged velocity and bottom stress for wind-driven flow in unstratified coastal waters is examined here. The adequacy of traditional linear and quadratic drag laws is addressed by comparison with a 2 1/2-D model. A 2 1/2-D model is one in which a simplified 1-D depth-resolving model (DRM) is used to provide an estimate of the relationship between the flow and bottom stress at each grid point of a depth-averaged model (DAM). Bottom stress information is passed from the DRM to the DAM in the form of drag tensor with two components: one which scales the flow and one which rotates it. This eliminates the problem of traditional drag laws requiring the flow and bottom stress to be collinear. In addition, the drag tensor field is updated periodically so that the relationship between the velocity and bottom stress can be time-dependent. However, simplifications in the 2 1/2-D model that render it computationally efficient also impose restrictions on the time-scale of resolvable processes. Basically, they must be much longer than the vertical diffusion time scale. Four progressively more complicated scenarios are investigated. The important factors governing the importance of bottom friction in each are found to be 1) non-dimensional surface Ekman depth ... is the surface shear velocity, f is the Coriolis parameter and h is the water depth 2) the non-dimensional bottom roughness, zo/h where zo is the roughness length and 3) the angle between the wind stress and the shoreline. Each has significant influence on the drag law. The drag tensor magnitude, r, and the drag tensor angle, 0 are functions of all three, while a drag tensor which scales with the square of the depth-averaged velocity has a magnitude, Cd, that only depends on zo/h. The choice of drag law is found to significantly affect the response of a domain. Spin up times and phase relationships vary between models. In general, the 2 1/2-D model responds more quickly than either a constant r or constant Cd model. Steady-state responses are also affected. The two most significant results are that failure to account for 0 in the drag law sometimes leads to substantial errors in estimating the sea surface height and to extremely poor resolution of cross-shore bottom stress. The latter implies that cross-shore near-bottom transport is essentially neglected by traditional DAMs.<br>by Harry Leonard Jenter, II.<br>Ph.D.
35
Giacaglia, Giuliano Pezzolo. "Integrating bottom-up and top-down information." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/91813.
Texte intégralRésumé :
Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2014.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 69-70).<br>In this thesis I present a framework for integrating bottom-up and top-down computer vision algorithms. I developed this framework, which I call the Map-Dictionary Pixel framework, because my intuition is that there is a need for tools that make it easier to build computer vision systems that mimic the way human visual systems process information. In particular, we humans humans create models of objects around us, and we use these models, top-down, to interpret, analyze and discern objects in the information that comes bottom-up from the visual world. After introducing my Map-Dictionary Pixel framework, I demonstrate how it empowers computer vision algorithms. I implement two different systems that extract the pixels of the image that correspond to a human. Even though each system uses different sets of algorithms, both use Map-Dictionary Pixel framework as the connecting pipeline. The two implementations demonstrate the utility of the Map-Dictionary Pixel framework and provide an example of how it can be used.<br>by Giuliano Pezzolo Giacaglia.<br>M. Eng.
36
Axelius, Torun, Josefine Hellström, Jessie Torpner, Yvonne Trinh, and Greyerz Karin von. "Office Recycling : Analys utifrån Triple Bottom Line." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-295323.
Texte intégralRésumé :
Office Recycling Sverige AB efterfrågade en hållbarhetsrapport som kan användasinom företaget men även mot kunderna. I studien analyserades processer i företagetför att undersöka och kunna optimera verksamheten där resultatet sedan kan användassom underlag till en hållbarhetsrapport. Som metod valdes Triple Bottom Line därekonomiska, miljömässiga och sociala aspekter ingår. Alla undersökningar sompresenteras i rapporten utfördes enligt denna modell.I studien undersöktes hur utformningen av en hållbarhetsrapport utförs samt hurimplementering av Triple Bottom Line sker i företagets verksamhet. Undersökningarutfördes dessutom på företaget i helhet vilket innefattar företagets verksamhet,transporter inom företaget, produkten Miljörör och certifieringar. Studien har givitkunskap om företagets struktur och vilka områden som behöver optimeras ochförbättras i framtiden.Ett flödesschema över företagets processer skapades för att bättre förståkommunikationen inom Office Recycling men även hur det ser ut mot kunderna. Deresultat som har erhållits är att kommunikationen inom företaget är bristfällig enligtenkätundersökningen som skickades ut till servicepersonalen. Enkäten gav ävenresultat om arbetsmiljön där servicepersonalen anser att arbetet är stressigt och tungt.Office Recycling är märkta med Bra Miljöval för företagets val av biogas somdrivmedel i transporterna vid hämtning av verksamhetsavfall. Företaget är ävencertifierad med Fossilfritt Sverige och ISO-standarderna inom kvalité och miljö, ISO9001 respektive ISO 14001.Office Recycling har fått en utökning av kunder vilket bidrar till investeringen i tvånya servicebilar. Servicebilarna måste placeras på ett optimalt sätt för att underlättaarbetsbördan hos servicepersonalen, därför har tre förslag tagits fram som har utgåttfrån ekonomiska, sociala och miljömässiga aspekter. Resultatet är att förslag två ärdet mest optimala av de tre förslagen.
37
Gibson, Peter. "The bottom of things : essences for explanation." Thesis, Birkbeck (University of London), 2014. http://bbktheses.da.ulcc.ac.uk/102/.
Texte intégralRésumé :
Central to the philosophy of Aristotle is the belief that the aim of serious enquiry is knowledge of the constitutive essences of a given field. Modern scientific essentialism claims that this still holds good, and this thesis aims to support that approach by elucidating and applying the original concept of essence. Chapter one argues that Aristotle formulated his theory of essences entirely in the context of the theory of explanation expounded in Posterior Analytics. The components of that theory are explained, and the implications of Aristotle’s view for current debate are considered. Chapter two examines the reasons for the decline of Aristotelian essentialism during the scientific revolution, the metaphysical problems which resulted, and Leibniz’s reasons for defending the older view. Chapter three considers the nature of explanation in a modern context, starting with the preconditions for any grasp of reality that are needed to make explanations possible; it is then argued that only essentialist explanation can occupy the role which these preconditions entail. Chapter four surveys the components of that picture of reality that seem explicable, to see how essentialist explanations would actually be formulated. The theoretical discussion concludes with an account of what form essences should take, in order to occupy the explanatory role that has been assigned to them. The final chapter examines the cases of counting physical objects, explaining abstract axiomatic systems, and the discovery of the periodic table of elements, showing how attempts at explanation in these cases all converge on the sorts of essence which have been delineated in the thesis.
38
Wilson, R. "Nanostructured bottom electrodes for ferroelectric thin films." Thesis, Cranfield University, 2001. http://dspace.lib.cranfield.ac.uk/handle/1826/10690.
Texte intégralRésumé :
Lead zirconate titanate
(PZT) is a oxide, which posseses a perovskite type structure.
The material is ferroelectric
making it technically useful for a diverse range of
applications from thermal imaging to non-volatile integrated memory devices. Thin
films of PZT are
commonly deposited onto platinised-silicon (Pt(111)/Ti/SíOX/Si)
bottom electrodes
by chemical solution deposition (CSD). Depending on the
conditions used a transient intermetallic
phase Pt3Pb can form in-situ with a (111)
preferred orientation during processing, which reduces the lattice mismatch between
the desired
perovskite phase and bottom electrode. Thereby, making it easier for the
perovskite phase to both nucleate and take on a preferred (111) orientation.
In the work
presented experiments were conducted on modifying the surface of
platinised-silicon to achieve a better lattice-match to Pb(Zr0_3Ti0_7)O3 (PZT30/70)
through coating, alloying or reacting the platinum with silver (Ag), gold (Au) or lead
(Pb). Single layer and multi-layer PZT thin fihns were deposited by a CSD method
onto these modified bottom electrodes and
plain platinised-silicon. Two precursor
sols were used one that had 10% excess Pb added
(PZT30/70) and one that had no
excess Pb added
(StoichPZT30/70). In general, two drying regimes prior to
crystallisation were employed for the precursor fihns.
i. Dried at 200°C for 3min
ii. Dried at 300°C for 5min
Crystallisation of the dried films was conducted i general at 480°C.
The
primary result of the work, showed that the presence of a lattice-matched
surface is
highly beneficial for nucleation of perovskite PZT and the subsequent
transformation from
amorphous precursor into perovskite PZT at low crystallisation
temperatures <500°C. All the modified bottom electrodes performed well when used
i
conjunction with fihns dried at 300°C for 5min, which otherwise would not
transform on plain platinised-silicon.
It was found that the Au and
Ag modified platinised-silicon behaved i a similar
manner to
plain platinised-silicon with respect to in-situ Pt3Pb, except that the Ag
modified
platinised-silicon appeared to impede its formation and promote its
oxidation. I
general the perovskite phase was detected by x-ray diffraction earlier
on
Ag modified platinised-silicon than on either Au modified or plain platinisedsilicon.
The
PZT30/70 thin films dried at 200°C for 3min on Au and
Ag modified
Abstract
bottom electrodes
appeared to have a higher crystallinity than similar than similar
films
deposited onto plain platinised-silicon. This was not observed for the
StoichPZT30/70 sol as the crystallinity of these films, dried at 200°C for 3mjn were
similar i value with all being greater than comparable PZT30/70 sol thin films.
It was also
proposed that the transformation rate from pyrochlore to perovskite
could be affected
by precursor sol Pb content and its distribution within the film
during crystallisation. This was illustrated when bottom electrodes containing Pt3Pb
before the film
deposition (ex-situ) were used. PZT30/70 films dried at 200°C for
3min, provide conditions for forming in-situ Pt3Pb and this produced poor quality
perovskite PZT thin films on ex-situ Pt3Pb. Implying that i the concentration of Pb is
too
high at the film/electrode, not only is the preferred orientation of the perovskite
thin film
compromised but also the degree of transformation from an amorphous to
the
perovskite phase will be compromised. However, StoichPZT30/70 films dried at
300°C for 5min do not form in-situ Pt3Pb on
crystallisation but When crystallised on
ex-situ Pt3Pb
they appear to transform rapidly into the perovskite phase with a
preferred (111) orientation.
39
João, Luís Mendes. "Millennium BCP: the bottom of the cycle." Master's thesis, NSBE - UNL, 2010. http://hdl.handle.net/10362/10282.
Texte intégral
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Gang, Andreas. "Towards bottom-up silicon nanowire-based biosensing:." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-235724.
Texte intégralRésumé :
The term "Lab-on-a-Chip" (LoC) describes highly miniaturized systems in which the functionalities of entire laboratories are scaled down to the size of transportable microchips. Particularly in the field of chemical and bio-analysis, such platforms are desired for a fast and highly sensitive sample analysis at the point of care. This work focuses on silicon nanowire (SiNW) based sensors. Innovative device fabrication concepts are developed from various directions, for a facile and reliable assembly of LoC analysis systems. Firstly, a multifunctional microfluidic set-up is developed which allows for a facile reversible sealing of channel structures on virtually any kind of substrate while maintaining the possibility of a rapid prototyping of versatile channel designs and the applicability of high working pressures of up to 600 kPa. Secondly, a 3-(triethoxysilyl)propylsuccinic anhydride (TESPSA) based surface modification strategy for the attachment of specific receptor molecules without additional binding site passivation is explored. Thirdly, bottom-up grown SiNWs are utilized for producing parallel arrays of Schottky barrier field-effect transistors (FETs) via contact printing. Using the initially developed microfluidic set-up, the concept of the TESPSA-based receptor immobilization is proved via fluorescence microscopy and by applying the SiNW FETs as biosensors. Using a receptor-analyte system based on a set of antibodies and a peptide from human influenza hemagglutinin, it is shown that antibodies immobilized with the developed method maintain the specificity for their antigens. The fourth major research field in this work is the microfluidics-based alignment of one-dimensional nanostructures and their deposition at predetermined trapping sites for reliably fabricating single NW-based FETs. Such devices are expected to provide superior sensitivity over sensors based on parallel arrays of FETs. Consequently, within this work, innovative LoC devices fabrication approaches over a broad range of length scales, from micrometer scale down to the molecular level, are investigated. The presented methods are considered a highly versatile and beneficial tool set not only for SiNW-based biosensors, but also for any other LoC application<br>Unter dem Begriff „Lab-on-a-Chip“ (LoC) fasst man stark miniaturisierte Systeme zusammen, die die Fähigkeiten eines ganzen Labors auf einen transportablem Mikrochip übertragen. Insbesondere im Bereich der Analyse chemischer und biologischer Proben werden solche Plattformen bevorzugt eingesetzt, da sie direkt am Ort der Probenentnahme schnelle, hoch sensible Messungen ermöglichen. Im Mittelpunkt dieser Doktorarbeit stehen Sensoren auf Basis von Siliziumnanodrähten (SiNWs). Auf verschiedenen Gebieten werden innovative Konzepte zur einfachen und zuverlässigen Herstellung von LoC Systemen entwickelt. Zu Beginn wird ein multifunktionaler Mikrofluidik-Aufbau vorgestellt, der ein einfaches reversibles Verschließen von Mikrofluidik-Kanälen auf nahezu allen möglichen Substraten erlaubt. Der Aufbau ermöglicht das schnelle Anfertigen und Testen verschiedener Kanalstrukturen sowie das Betreiben von Fluidik-Experimenten mit hohen Arbeitsdrücken von bis zu 600 kPa. Der zweite Schwerpunkt der Arbeit ist die Entwicklung einer Methode zur Funktionalisierung von Sensor-Oberflächen mittels 3-(Triethoxysilyl) Propyl Bernsteinsäure Anhydrid (TESPSA) für die Immobilisierung spezifischer Rezeptormoleküle. Bei dieser Methode entfällt die Notwendigkeit einer zusätzlichen Passivierung ungenutzter Anbindungsstellen. Des Weiteren erfolgt die Herstellung von Parallelschaltungen von Schottky-Barrieren-Feld-Effekt-Transistoren (SB-FETs) aus „bottom-up“ gewachsenen SiNWs durch mechanisches Abreiben der SiNWs vom Wachstumssubstrat auf ein Empfängersubstrat. Unter Verwendung des eingangs entwickelten Mikrofluidik-Aufbaus wird die prinzipielle Anwendbarkeit der TESPSA-basierten Rezeptor-Immobilisierung nachgewiesen, sowohl anhand von Fluoreszenzmikroskopie-Untersuchungen als auch mit Hilfe der SiNW FETs als Biosensoren. Mittels eines Rezeptor-Analyt-Systems, bestehend aus verschiedenen Antikörpern und einem Peptid des Influenzavirus A, wird gezeigt, dass Antikörper, die über TESPSA an Oberflächen gebunden werden, ihre Spezifizität für ihre Antigene beibehalten. Der vierte große Forschungsabschnitt dieser Arbeit widmet sich der mikrofluidischen Ausrichtung eindimensionaler Nanomaterialien und deren Ablage an vorgegebenen Fangstellen, wodurch eine zuverlässige Herstellung von FETs aus Einzelnanodrähten erreicht wird. Es wird davon ausgegangen, dass Einzelnanodraht-FETs gegenüber Parallelschaltungen von Nanodraht-FETs verbesserte Sensoreigenschaften aufweisen. Folglich beinhaltet diese Arbeit viele zukunftsweisende Ansätze für die Herstellung von LoC Systemen. Untersuchungen über eine Bandbreite von Längenskalen, von Mikrometer großen Strukturen bis hinab zur molekularen Ebene, werden präsentiert. Es wird davon ausgegangen, dass die vorgestellten Methoden als eine vielfältige Sammlung von Werkzeugen nicht nur bei der Herstellung von Biosensoren auf SiNW-Basis Einsatz finden, sondern ganz allgemein den Aufbau verschiedenster LoC Systeme vorantreiben
41
Bokun, I. A. "Bottom-Up Diversity of Foreign Language Courses." Thesis, Українська академія банківської справи Національного банку України, 2010. http://essuir.sumdu.edu.ua/handle/123456789/62705.
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Fan, Jiufeng. "Bottom-Up Design of Synthetic Photoactive Metalloproteins." Bowling Green State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1256410648.
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Blaser, Kristeena K. "The Triple Bottom Line of Sustainable Fashion." Ohio University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1493839389457047.
Texte intégral
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Dutkiewicz, Marek Karol. "Synthetic aperture sonar for sub bottom imaging." Master's thesis, University of Cape Town, 1986. http://hdl.handle.net/11427/21962.
Texte intégralRésumé :
The major problems associated with implementing synthetic apertures in sonar may be overcome by applying the technique to sub-bottom imaging. The use of a low frequency aids both penetration of the sediment and the attainment of long coherent apertures. The implementation of synthetic apertures realises a narrow fan beam. By directing this beam out sideways, a more rapid survey rate is possible than that achieved by the normal echo-sounding mode used in sub-bottom profiling. The synthetic aperture technique appears to offer significant advantages over that of parametric arrays, for high resolution sub-bottom imaging. Synthetic apertures have been implemented in a laboratory tank, under controlled conditions at a fresh water reservoir, and under realistic operational conditions at sea. Encouraging results have been obtained.
45
Lee, Boon Chuan. "Environmental influence on shallow water bottom reverberation." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://sirsi.nps.navy.mil/uhtbin/hyperion-image/02Mar%5FLeeBC.pdf.
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de-la-Ossa-Carretero, Jose Antonio. "Assessing sewage disposals in soft-bottom habitats." Doctoral thesis, Universidad de Alicante, 2011. http://hdl.handle.net/10045/24056.
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47
Kjelldorff, Maria. "Water Current Measurements using Oceanographic Bottom LanderLoTUS?" Thesis, KTH, Marina system, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-261697.
Texte intégralRésumé :
oTUS is a Long Term Underwater Sensing, bottom landing, node for observations of ocean water temperatures. LoTUS measures temperature (moored to the seafloor) according to a spec-ified time schedule until, at the end of the mission, it surfaces to transmit the collected data to on shore recipients using an Iridium link. The paper presents an extension of the sensing capability to include water current velocity (speed and direction) using a robust, reliable and inexpensive Eulerian method. The method is based on the "tilting stick" principle where a combination of inertia measurement data and magnetic sensor data is used. The paper discusses the principal technique, the modeling of the system, practical considerations, and optimization of the setup for specific flow conditions along with verifying experimental data.
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Erlingsson, Ulf. "Geomorphological development of the bottoms off Österlen, southernmost Sweden." Uppsala, Sweden : Uppsala University, Dept. of Physical Geography, 1990. http://catalog.hathitrust.org/api/volumes/oclc/22874540.html.
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Riou, Mathilde, and Diniz Elisa Carvalho. "Bottom up urbanism : Exploring the potential of bottom up initiatives as to encourage pro-environmental behaviour change and action." Thesis, KTH, Urbana och regionala studier, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-209218.
Texte intégralRésumé :
It has been widely acknowledged that environmental damage and changes in the global climate can be attributed to human activities. In their attempt to deal with these issues, current top down approaches to mitigate climate change not only have limited efficacy, but also fail at changing people’s behaviour. In this thesis, we argue that bottom up initiatives can be more successful at engaging people in pro-environmental behaviour change and action than the current top down strategies. The potential of bottom up actions to encourage such change and action is first assessed in literature. A more specific perspective of bottom up initiatives is looked at in which pro-environmental behaviour is encouraged and observed through the lens of urbanism. A practical event on sustainability, co-organized by the authors of this paper at KTH Campus, is then taken as a case study to test and verify if bottom up actions can bring about change in behaviours and generate public engagement in public spaces. The results show that bottom up actions have great potential to reach the community and engage people into sustainable practices. As it was positive and solution-oriented, but also accessible, participative and fun, the event easily attracted people’s attention and interest. The stimulating environment then facilitates the process of sharing and learning information and consequently, it also increases the chances of influencing behaviour change and action.
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Davies, Paul. "Sub-fossil mollusca from Holocene overbank alluvium and other wet-ground contexts in Wessex." Thesis, Cardiff University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.281700.
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