Dissertations / Theses on the topic 'Flippers'
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Yavar, Alexander, and Victor Öfverberg. "Flippers on the real estate market." Thesis, KTH, Fastigheter och byggande, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-189265.
Full textA flippers role in the market refers to individuals who purchase real estate, either in the new market or on the after market in order to serve the housing and thus never move into them. Their investment is called speculator investments and has become more common the last five years. A flippers effect on housing and real estate market is that they create and affect market pricing. This study has used an inductive research method that combines literature and an empirical approach representing interviews. There have been three interviews with real estate companies: BoKlok, Abacus and Järntorget Bostad combined with interviews with FMF and theorist Hans Lind. In Sweden, Flippers are investing most in central Stockholm, according to hints from the FMF but are current in both markets. Generally there are no negative view of flipping, but concerns about how business is done and to what extent it can affect other hand the buyers and what would happen if the market turns - and the consequences of flipping folds of the developers. The result shows that flipping can have negative consequences in the buying process of new construction when it is it brings the greatest risk of market swings, and of second-hand buyers who might have problems after admission if flipping was done under false pretenses.
Fernando, Waduge Pradeep Lasantha. "Lack of Molecular Chaos and Role of Stochasticity in KAC's Ring Model." University of Akron / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=akron1259607415.
Full textFlippin, Stefanie Lee. "Synthesis of phospholipid analogs /." Electronic version (PDF), 2003. http://dl.uncw.edu/etd/2003/flippins/stefanieflippin.pdf.
Full textJantos, Anne, Matthias Heinz, Eric Schoop, and Ralph Sonntag. "Migration to the Flipped Classroom – Applying a Scalable Flipped Classroom Arrangement." TUDpress, 2016. https://tud.qucosa.de/id/qucosa%3A33955.
Full textNorgren, Marcus. "Flipped Classroom på högstadiet." Thesis, Högskolan i Gävle, Avdelningen för elektronik, matematik och naturvetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-17014.
Full textEriksson, David. "Flipped Classroom i gymnasieskolan." Thesis, Luleå tekniska universitet, Pedagogik, språk och Ämnesdidaktik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-64073.
Full textBergman, Jennifer. "Flipped eller bara flippat? En fenomenografisk studie av elevers upplevelse av Flipped Classroom." Thesis, Högskolan Dalarna, Akademin Utbildning, hälsa och samhälle, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:du-15424.
Full textMazouchova, Nicole. "Principles of fin and flipper locomotion on granular media." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/47645.
Full textKaiser, Andre, Anja Lorenz, Barbara Dinter, Tom Hänel, and Carsten Felden. "Flipped Classroom in der Wirtschaftsinformatik." Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-183503.
Full textLarsson, Jonas. "Bättre undervisning med Flipped Classroom?" Thesis, Malmö högskola, Fakulteten för lärande och samhälle (LS), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-33637.
Full textNordenbris, A. Victor V., and Jens D. E. Höglund. "Inlärning i ett flipped classroom." Thesis, Malmö högskola, Fakulteten för lärande och samhälle (LS), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-29770.
Full textKitts, Mallory. "Practicality of the Flipped Classroom." Ohio Dominican University Honors Theses / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=oduhonors1398457608.
Full textSalfen, Kevin McGregor. "Paintings and Palaces, or the Lament of the Burger Flipper." Thesis, University of North Texas, 1999. https://digital.library.unt.edu/ark:/67531/metadc2186/.
Full textJohnson, Graham Brent. "Student perceptions of the Flipped Classroom." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44070.
Full textAbel, S. A. "The phenomenology of flipped SU(5)." Thesis, University of Bristol, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.279687.
Full textDafoe, Kendra. "Caring in a Flipped Mathematics Classroom." University of Toledo / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1479068152120649.
Full textHalgasch, Jana, and Tanja Sonntag. "Additive Vermittlung von Schlüsselkompetenzen mit der Flipped Classroom-Methode am Career Service der HTW Dresden – Flipped Consulting." TU Bergakademie Freiberg, 2018. https://tubaf.qucosa.de/id/qucosa%3A31208.
Full textLorenz, Anja, Annett Einert, and Barbara Dinter. "FC WInf: Flipped Classroom in der Wirtschaftsinformatik." Universitätsbibliothek Chemnitz, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-96870.
Full textPerselli, Viktor. "Flipped Classroom im Fremdsprachenunterricht - Möglichkeiten und Herausforderungen." Thesis, Linköpings universitet, Institutionen för kultur och kommunikation, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-136534.
Full textÖström, Mathias. "Flipped Classroom – hur ser kemielever på metoden?" Thesis, Malmö universitet, Fakulteten för lärande och samhälle (LS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-35637.
Full textHampton, Shannon. "A preliminary investigation into effects of flipper banding on African penguins spheniscus demersus." Master's thesis, University of Cape Town, 2007. http://hdl.handle.net/11427/6265.
Full textIncludes bibliographical references.
Much of what is known about penguin movements and life history traits, including their population dynamics, and particularly the rehabilitation success after oil spills results from information derived from marking birds with flipper bands. However, flipper bands may negatively impact the welfare of penguins. While studies on the impact of banding have been undertaken for several penguin species, no such study has investigated the exclusive effect of banding on African Penguins Spheniscus demersus. I do so by comparing the difference in yearly return rates as well as foraging trip durations of 100 individuals injected with a subcutaneous transponder only, and 100 that have both transponders and a stainless steel flipper band.
Fuchs, Kevin. "Merits of the Flipped Classroom : Distance-students’ perception of usefulness and challenges regarding the flipped classroom concept in higher education." Thesis, Linnéuniversitetet, Institutionen för informatik (IK), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-97167.
Full textStåhl, Mikael, and Henrik Wiberg. "Flippad kompetensutveckling : Flipped Classroom, en framtid för arbetsplatslärande." Thesis, KTH, Skolan för teknikvetenskaplig kommunikation och lärande (ECE), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-188912.
Full textEric Mazur, professor at Harvard University, began in 1990 using what would later become flipped classroom. He wanted to try a new method in teaching. He let the students read from the textbook in advance of a lecture so that when they came to class they were all prepared. The students would then work with practical exercises in the classroom where they got to apply the beforehand studied material. This report seeks to investigate how companies work with increasing the internal competence through education. The main purpose of the report is to evaluate the potential of flipped classroom as a method for competence development in company environments. The theoretical framework upon which this thesis is build consist mainly of Jack Mezirow and his work about adult learning and how to successfully educate adults, and Knud Illeris’s work on how knowledge is acquired by the individual. Competence as a concept can be traced back to Aristoteles fronesis, which translates approximately to practical knowledge. Today there is no universal definition of competence and different institutions ascribe different meaning to the word. The data was collected by using participating observations on courses given by the evaluated company along with questionnaires that were handed out at the observed courses. This along with interviews and interaction pattern observations at the given courses constituted the result of this thesis. The result of this indicates that the course participants experience a need for more discussions and exercises. The participants experience that time could be used more efficiently to cover the intended material. The result also indicates that there is a desire for more exchange of experience among the participants and the course subject needs to be better anchored and related to each participant’s work and life situation. This study shows that flipped classroom is a method which could be used to make course participant more activated and through that facilitate a better and more effective learning. This would benefit the economy of the company more. It has surfaced during this study that a future area in which there is a need for research is in how company work with validating the acquired knowledge during a course.
Gross, Anna Lynn. "The Flipped Classroom: Shakespeare in the English Classroom." Thesis, North Dakota State University, 2014. https://hdl.handle.net/10365/27512.
Full textSkarenstedt, Jeff. "Students´ perception about flipped classroom in learning mathematics." Thesis, Malmö universitet, Fakulteten för lärande och samhälle (LS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-29564.
Full textRomaker, Dana Elizabeth. "Benefits of Flipped Learning for Developmental Math Students." University of Findlay / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=findlay1595596549929419.
Full textArner, Tracy. "Investigating the Flipped Classroom in Undergraduate Educational Psychology." Kent State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=kent1604926621821785.
Full textLerche, Jenny. "Flipped Classroom in der Hochschullehre der TU Dresden – Ein Work in Progress-Bericht." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-181469.
Full textStrohmyer, Daniel. "Student Perceptions of Flipped Learning in a High School Math Classroom." ScholarWorks, 2016. https://scholarworks.waldenu.edu/dissertations/2178.
Full textÖlmefors, Oscar. "Student Attitudes towards Flipped Classroom : A Focus Group Study on Attitude Change in Swedish Upper Secondary School, within Mathematics towards Flipped Classroom." Thesis, KTH, Skolan för teknikvetenskaplig kommunikation och lärande (ECE), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-189170.
Full textEmanuelsson, Tobias. "Matematikundervisning i det virtuella klassrummet : Flipped Classroom i praktiken." Thesis, Högskolan i Halmstad, Sektionen för lärarutbildning (LUT), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-26107.
Full textSarli, Mustafa Alper. "Perceptions of International Students in Poland Regarding Flipped Classrooms." ScholarWorks, 2019. https://scholarworks.waldenu.edu/dissertations/7075.
Full textSpeller, Sandra. "Mathematics Teacher’s Experience with Flipped Learning: A Phenomenographic Approach." University of Toledo / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1449855833.
Full textAndersson, Hanna. "Den flippade läxan : En systematisk litteraturstudie av läxor i det flippade matematikklassrummet." Thesis, Linköpings universitet, Matematik och tillämpad matematik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-153116.
Full textThe purpose of this study is to investigate homework given in the flipped mathematics classroom. One of the characteristics of the “flipped classroom” is that traditional lectures are not placed in class time. Direct instruction is instead given as homework, “flipped homework”, often in the form of video lectures. The literature review is based on nine articles and focuses on the design of flipped mathematics homework, pupil’s views of the method, and the possible advantages and disadvantages of flipped homework in relation to traditional homework. There is still a lack of research done on “flipped homework”, which makes it difficult to draw any general conclusions. However, the results indicate that the teaching method may have some advantages, including that video lectures gives the students a greater responsibility for their own learning, and that the fixed time of the video have the potential to reduce the difference in time spent by different students on the same homework.
Tong, Tracy. "Exploring the flipped classroom in a Hong Kong secondary school." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/209689.
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Master of Education
Bernard, Jean S. "Nurse Educators' Transition to Flipped Classroom: An Interpretive Description Study." Digital Commons @ East Tennessee State University, 2015. https://dc.etsu.edu/etd/2603.
Full textCosta, Natália Marisa Senra da. "Flipped classroom em aulas práticas experimentais de biologia e geologia." Master's thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/14985.
Full textO presente trabalho teve por finalidade analisar de que modo a abordagem Flipped Classroom pode contribuir para a aprendizagem significativa dos alunos em aulas práticas experimentais de Biologia e Geologia. O Flipped Classroom é uma abordagem de ensino na qual os alunos visualizam os vídeos Flipped Classroom fora da sala de aula, como trabalho de casa, permitindo que, no tempo de aula, se realizem exercícios e atividades práticas, com base no que aprenderam através dos vídeos Flipped Classroom visualizados. Desenvolveu-se um estudo de caso com o objetivo de compreender a opinião dos alunos face ao uso da abordagem Flipped Classroom em aulas práticas experimentais e de fazer um levantamento das potencialidades e limitações desta, numa turma do 11ª ano numa escola secundária do distrito de Aveiro. O estudo permitiu verificar a aplicabilidade da abordagem Flipped Classroom nas aulas práticas experimentais de Biologia e Geologia. Apesar de alguma resistência inicial à abordagem , são significativas as conclusões e bastante positivos os resultados: - Os vídeos Flipped Classroom foram vistos como uma mais-valia na aprendizagem, pois verificou-se um incremento do sentido de responsabilidade e autonomia nos alunos ao longo do processo. - A gestão de tempo em sala de aula alterou-se, registando-se mais oportunidades para a concretização de atividades colaborativas, permitindo, ao mesmo tempo, o cumprimento do programa. - O papel do professor mudou, tornando-se mais coordenador e facilitador da aprendizagem, na medida em que tem mais tempo para desenvolver atividades com os alunos, o que implica uma reestruturação do tempo de aula e consequente preparação de estratégias diversificadas.
The aim of this study is to analyse how the Flipped Classroom approach can contribute to meaningful learning practices of students in Biology and Geology’s experimental classes . The Flipped Classroom is a teaching approach in which students visualise Flipped Classroom videos outside the classroom, working from home, in order to save time in classes to do practical exercises and activities, based on what they have learnt through the visualised Flipped Classroom videos. A case study was developed in a 11th grade class in a secondary school of Aveiro, whose aim was to know the students’ opinion on the use of the Flipped Classroom approach in experimental practical lessons as well as assess its potential and limitations. The study allowed us to check the applicability of the Flipped Classroom approach in experimental practical lessons in Biology and Geology. In spite of some resistence to this approach in the beginning, the results were very positive: - The Flipped Classroom videos proved to be of significant value in the students’ learning, giving them responsibility and autonomy during the process; - There was a change in the classroom time management as there were more opportunities to do other collaborative activities and at the same time the programm was accomplished; - The teacher's role has changed, he is now a coordinator and a facilitator of the students’ learning, having more time to develop different activities and new strategies with them.
Moreira, Ana Catarina Carvalho. "Flipped classroom : aplicação em aulas teóricas de biologia e geologia." Master's thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/14667.
Full textAtualmente o maior objetivo na educação é formar alunos socialmente ativos, sendo da maior importância melhorar o processo de ensino e de aprendizagem. Para tal é necessário repensar as abordagens de ensino correntes em sala de aula, para que as mesmas possam atender às várias necessidades inerentes ao processo de ensino e de aprendizagem. Este trabalho apresenta a abordagem de ensino Flipped Classroom, como promotora da modificação do ensino tal como hoje se apresenta. Descreve uma experiência de aplicação desta abordagem, as implicações da mesma, e as opiniões dos alunos participantes do 10º e 11º ano do ensino secundário. Esta investigação tem como finalidade conhecer os contributos da abordagem Flipped Classroom para o desempenho dos alunos na resolução de exercícios, descobrir as perceções que estes têm sobre a abordagem em causa, e por fim, perceber se existe alguma relação entre os hábitos dos alunos durante a resolução de exercícios e o seu desempenho. Neste estudo utilizou-se informações provenientes de diversas técnicas e instrumentos de recolha de dados, nomeadamente, observação, análise documental e questionários. Concluiu-se desta investigação que o Flipped Classroom faz com que os alunos se sintam confiantes na aula, mais especificamente na resolução de exercícios, pois estes conseguem fazer uma melhor utilização dos conteúdos temáticos que foram abordados nos vídeos fornecidos. Quanto às suas perceções os alunos afirmam que o Flipped Classroom é uma mais-valia para o processo de aprendizagem, apesar de considerarem negativo o facto de este exigir elevada disponibilidade, trabalho e empenho da sua parte.
Currently the biggest goal in education is to train students socially active and improve the process of teaching and learning. This requires rethinking of current approaches on classroom teaching, in order to meet the various needs inherent on the teaching and learning process. This paper presents the Flipped Classroom teaching approach, as teaching modifying promoter, as it stands today. It describes an experience of this approach applications and consequences, including the student participations considerations of the 10th and 11th classroom grades of high school. This research aims to know the contributions of the Flipped Classroom approach to a better students performance, their perceptions on Flipped Classroom approach, and, finally, evaluate if there is any connection between student habits and exercise solving performance. In this study is used information from several techniques and tools of data collection, as observation, document analysis and questionnaires. It was concluded on this research that Flipped Classroom makes students feel confident on classroom, specifically on problem solving, and best use of thematic contents covered on videos. Regarding student perceptions, they assume that Flipped Classroom is positive on their learning process, although the approuch requires high student availability, commitment and work.
Maynard, Julie Ann. "Transformational Teaching & Learning Modeled in a Flipped Classroom Environment." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555355104583446.
Full textCheung, Ho-yin. "The flipped classroom from the perspective of higher education students." Thesis, University of Bristol, 2017. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.723486.
Full textTeixeira, Gisel Pinto. "Flipped Classroom: Um contributo para a aprendizagem da lírica camoniana." Master's thesis, Faculdade de Ciências Sociais e Humanas, Universidade Nova de Lisboa, 2013. http://hdl.handle.net/10362/11379.
Full textO método de ensino-aprendizagem flipped classroom com recurso ao vídeo e ao vodcast em modalidade de b-learning tem recebido muito atenção por parte dos media e blogs educacionais nos EUA. Neste método de ensino-aprendizagem, os alunos assistem à exposição oral de conteúdos através de vídeos ou vodcasts fora da sala de aula (como trabalho de casa), preparando-se, desta forma, para as atividades a desenvolver em espaço de sala de aula, isto é, colocando em prática o que aprenderam através da resolução de exercícios e desenvolvimento de projetos, privilegiando-se a estratégia de trabalho colaborativo. Este trabalho de projeto procura confirmar ou infirmar a aplicabilidade deste método de ensino-aprendizagem ao estudo de uma unidade literária como a lírica camoniana. Assim, desenvolveu-se um estudo de caso com o objetivo de não só compreender as perceções de alunos e professores face ao uso de vodcasts e de flipped classroom como fazer um levantamento das vantagens e desvantagens do método no ensino-aprendizagem do texto poético camoniano, numa turma do 10º ano de escolaridade, numa escola internacional em Portugal. A amostra intencional e de conveniência era composta por uma turma 19 alunos e por um grupo de 5 docentes com experiência no ensino da sequência de aprendizagem. Recorreu-se a instrumentos metodológicos qualitativos, como entrevistas semiestruturadas, diário de bordo, observação direta e participante e inquérito por questão aberta bem como a instrumentos quantitativos como inquérito por questão fechada com escala de tipo Likert, para melhor compreender o caso em estudo. O estudo permitiu concluir que: (i) o método flipped classroom é uma estratégia eficaz na consecução de objetivos de aprendizagem de uma unidade literária como a lírica camoniana; (ii) os alunos viveram uma fase inicial de habituação a um método diverso do tradicional, tendo-se incrementado o sentido de responsabilidade pela auto-aprendizagem; (iii) verificou-se alguma frustração inicial, pois os alunos não viam as suas dúvidas esclarecidas no imediato aquando do visionamento dos vodcasts; (iv) a observação dos recursos exigiu mais concentração e o desenvolvimento de estratégias de estudo como o registo de apontamentos e das dúvidas suscitadas; (v) o recurso ao vodcast foi visto como uma mais-valia na revisão de conteúdos e no estímulo de uma aprendizagem ao ritmo próprio do aluno, pelas suas funcionalidades de pausa e repetição bem como disponibilidade ubíqua online; (vi) a gestão de tempo em aula alterou-se, havendo mais oportunidade para concretização de atividades colaborativas sem prejuízo do cumprimento do programa; (vii) verificou-se o incremento da interação aluno-aluno e professor-aluno, promovendo-se uma abordagem socioconstrutivista; (viii) o papel do professor alterou-se, já que se investiu mais tempo de aula como tutor e gestor de saberes, o que implicou a reconceptualização da estrutura do tempo letivo.
Fassmann, Wesley N. "An Experimental Study of Bio-Inspired Force Generation by Unsteady Flow Features." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/5316.
Full textPavarani, Alice. "Flipped classroom. Illustrazione del modello di insegnamento e resoconto di un'esperienza didattica." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/7066/.
Full textSjöquist, Sebastian, and Petter Karkea. "Lärares attityder till e-föreläsningar : En intervjustudie av lärares attityder till e-föreläsningar." Thesis, Umeå universitet, Institutionen för informatik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-124772.
Full textFjällborg, Anna. "Digital undervisning i textilslöjden : -en undersökning av digitala hjälpmedel och nätbaserad kommunikation." Thesis, Umeå universitet, Institutionen för estetiska ämnen i lärarutbildningen, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-90614.
Full textMaddison, Tasha, Donna Beneteau, and Brandy Sokoloski. "Breaking Ground: Improving Undergraduate Engineering Projects through Flipped Teaching of Literature Search Techniques." Issues in Science and Technology Librarianship, 2014. http://hdl.handle.net/10388/6508.
Full textZachrisson, Daniel. "Flipped classroom : En undersökning om vad eleverna tycker om olika typer av videoföreläsningar i matematiken." Thesis, Högskolan i Gävle, Avdelningen för elektroteknik, matematik och naturvetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-34706.
Full textMarlowe, Cara A. "The effect of the flipped classroom on student achievement and stress." Montana State University, 2012. http://etd.lib.montana.edu/etd/2012/marlowe/MarloweC0812.pdf.
Full textFinkenberg, Frank [Verfasser], Thomas [Gutachter] Trefzger, and Roger [Gutachter] Erb. "Flipped Classroom im Physikunterricht / Frank Finkenberg ; Gutachter: Thomas Trefzger, Roger Erb." Würzburg : Universität Würzburg, 2018. http://d-nb.info/1163201820/34.
Full textWeber, Paul William. "Probabilistic Modeling of Decompression Sickness, Comparative Hydrodynamics of Cetacean Flippers, Optimization of CT/MRI Protocols and Evaluation of Modified Angiocatheters: Engineering Methods Applied to a Diverse Assemblage of Projects." Diss., 2010. http://hdl.handle.net/10161/3017.
Full textThe intent of the work discussed in this dissertation is to apply the engineering methods of theory/modeling, numerics/computation, and experimentation to a diverse assemblage of projects. Several projects are discussed: probabilistic modeling of decompression sickness, comparative hydrodynamics of cetacean flippers, optimization of CT/MRI protocols, evaluation of modified catheters, rudder cavitation, and modeling of mass transfer in amphibian cone outer segments.
The first project discussed is the probabilistic modeling of decompression sickness (DCS). This project involved developing a system for evaluating the success of decompression models in predicting DCS probability from empirical data. Model parameters were estimated using maximum likelihood techniques, and exact integrals of risk functions and tissue kinetics transition times were derived. Agreement with previously published results was excellent including maximum likelihood values within one log-likelihood unit of previous results and improvements by re-optimization, mean predicted DCS incidents within 1.4% of observed DCS, and time of DCS occurrence prediction. Alternative optimization and homogeneous parallel processing techniques yielded faster model optimization times. The next portion of this project involved investigating the nature and utility of marginal decompression sickness (DCS) events in fitting probabilistic decompression models to experimental dive trial data. Three null models were developed and compared to a known decompression model that was optimized on dive trial data containing only marginal DCS and no-DCS events. It was found that although marginal DCS events are related to exposure to decompression, empirical dive data containing marginal and full DCS outcomes are not combinable under a single DCS model; therefore, marginal DCS should be counted as no-DCS events when optimizing probabilistic DCS models with binomial likelihood functions. The final portion of this project involved the exploration of a multinomial DCS model. Two separate models based on the exponential-exponential/linear-exponential framework were developed: a trinomial model, which is able to predict the probabilities of mild, serious and no-DCS simultaneously, and a tetranomial model, which is able to predict the probabilities of mild, serious, marginal and no-DCS simultaneously. The trinomial DCS model was found to be qualitatively better than the tetranomial model, for reasons found earlier concerning the utility of marginal DCS events in DCS modeling.
The next project discussed is comparative hydrodynamics of cetacean flippers. Cetacean flippers may be viewed as being analogous to modern engineered hydrofoils, which have hydrodynamic properties such as lift coefficient, drag coefficient and associated efficiency. The hydrodynamics of cetacean flippers have not previously been rigorously examined and thus their performance properties are unknown. By conducting water tunnel testing using scale models of cetacean flippers derived via computed tomography (CT) scans, as well as computational fluid dynamic (CFD) simulations, a baseline work is presented to describe the hydrodynamic properties of several cetacean flippers. It was found that flippers of similar planform shape had similar hydrodynamic performance properties. Furthermore, one group of flippers of planform shape similar to modern swept wings was found to have lift coefficients that increased with angle of attack nonlinearly, which was caused by the onset of vortex-dominated lift. Drag coefficient versus angle of attack curves were found to be less dependent on planform shape. Larger cetacean flippers were found to have degraded performance at a Re of 250,000 compared to flippers of smaller odontocetes, while performance of larger and smaller cetacean flippers was similar at a swim speed of 2 m/s. Idealization of the planforms of cetacean flippers was found to capture the relevant hydrodynamic effects of the real flippers, although unintended consequences such as the lift curve slope changing from linear to nonlinear were sometimes observed. A numerical study of an idealized model of the humpback whale flipper showed that the leading-edge tubercles delay stall compared to a baseline (no tubercle) flipper because larger portions of the flow remaining attached at higher angles of attack.
The third project discussed is optimization of CT/MRI protocols. In order to optimize contrast material administration protocols for Computed Tomography (CT) and Magnetic Resonance Imaging (MRI), a custom-built physiologic flow phantom was constructed to model flow in the human body. This flow phantom was used to evaluate the effect of varying volumes, rates, and types of contrast material, use of a saline chase, and cardiac output on aortic enhancement characteristics. For CT, reducing the volume of contrast material decreased duration peak enhancement and reduced the maximum value of peak enhancement. Increasing the rate of contrast media administration increased peak enhancement and decreased duration of peak enhancement. Use of a saline chase resulted in an increase in peak enhancement. Peak aortic enhancement increased when reduced cardiac output was simulated. For MRI, when the same volume of contrast material was injected at the same rate, the type of contrast material used has a significant effect on the greatest peak signal intensity and duration peak signal intensity. A higher injection rate of saline chaser is more advantageous than a larger volume of saline chaser to increase the peak aortic signal intensity using low contrast material doses. Furthermore, for higher volumes of contrast material, the effect of increasing the volume of saline chaser makes almost no difference while increasing the rate of injection makes a significant difference. When a saline chaser with a high injection rate is used, the dose of the contrast material may be reduced by 25-50% and more than 86% of the non-reduced dose peak aortic enhancement will be attained.
The next project discussed is evaluation of modified angiocatheters. In this study, a standard peripheral end hole angiocatheter was compared to those modified with side holes or side slits by using experimental techniques to qualitatively compare the contrast material exit jets, and by using numeric techniques to provide flow visualization and quantitative comparisons. A Schlieren imaging system was used to visualize the angiocatheter exit jet fluid dynamics at two different flow rates, and a commercial computational fluid dynamics (CFD) package was used to calculate numeric results for various catheter orientations and vessel diameters. Experimental images showed that modifying standard peripheral intravenous angiocatheters with side holes or side slits qualitatively changed the overall flow field and caused the exiting jet to become less well-defined. Numeric calculations showed that the addition of side holes or slits resulted in a 9-30% reduction of the velocity of contrast material exiting the end hole of the angiocatheter. With the catheter tip directed obliquely to the wall, the maximum wall shear stress was always highest for the unmodified catheter and always lowest for the 4 side slit catheter. Modified angiocatheters may have the potential to reduce extravasation events in patients by reducing vessel wall shear stress.
The next project discussed involves studying the effect of leading-edge tubercles on cavitation characteristics for marine rudders. Three different rudders were constructed and tested in a water tunnel: baseline, 3-tubercle leading edge, and 5-tubercle leading edge. In the linear (non-stall) regime, tubercled rudders performed equally to the smooth rudder. Hydrodynamic stall occurred at smaller angles of attack for the tubercled rudders than for the smooth rudder. When stall did occur, it was more gradual for the tubercled rudders, whereas the smooth rudder demonstrated a more dramatic loss of lift. At lower Re, the tubercled rudders also maintained a higher value of lift post-stall than the smooth rudder. Cavitation onset for the tubercled rudders occurred at lower angles of attack and higher values of cavitation number than for the smooth rudder, but cavities on the tubercled rudders were localized in the slots as opposed to the smooth rudder where the cavity spread across the entire leading edge.
In the final project discussed, modeling of mass transfer in amphibian cone outer segments, a detailed derivation of a simplified (continuum, one-dimensional) mathematical model for the radio-labeled opsin density profile in the amphibian cone outer segment is presented. This model relies on only one free parameter, which was the mass transfer coefficient between the plasmalemma and disc region. The descriptive equations were nondimensionalized, and scale analysis showed that advective effects could be neglected as a first approximation for early times so that a simplified system could be obtained. Through numeric computation the solution behavior was found to have three distinct stages. The first stage was marked by diffusion in the plasmalemma and no mass transfer in the disc region. The second stage first involved the plasmalemma reaching a metastable state whereas the disc region density increased, then involved both the plasmalemma and disc regions increasing in density with their distributions being qualitatively the same. The final stage involved a slow relaxation to the steady-state solution.
Dissertation