Dissertations / Theses: 'Winglets'

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Duong, Thang. "Analys av potentialen för rörliga winglets på framtidens kortdistansflygplan." Thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-35742.

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Flygindustrin fortsätter kontinuerligt att växa, med nyare och effektivare flygplan skapar flygbolagen en konkurrenskraft flygbolag emellan samtidigt som de säkrar deras egna framtid med vinster och besparingar i respektives ekonomi. Syftet med denna rapport är att bedöma potentialen för rörliga winglets på framtidens kortdistansflygplan. Kan detta koncept skära ner på flygbolagens ekonomi? Med oljeprisets historiska utveckling går det att fastställa att olika händelser runtom i världen kan påverka utveckling antingen negativt eller positivt. Genom konceptet rörliga winglets kan flygbolag förebygga de negativa konsekvenserna av oljeprisutvecklingen och i bästa fall öka de positiva konsekvenserna. För att bedöma potentialen fokuseras arbetet på följande två frågeställningar: Kan anpassningsbara winglets leda till en förbättring? Hur ser de mekaniska- och aerodynamiska krafterna ut på wingletsen vid förbättring? Angreppsättet av frågeställningarna har gått till på sådant vis att krafterna som verkar på wingletsen har gjorts om till vektorer. Genom att vektorer användes för att undersöka frågeställningarna blev det lättare att illustrera samt matematiskt beräkna effekterna vid olika kantvinklar och anfallsvinklar. Resultatet visade att det finns en förbättringsmöjlighet på dagens winglets. Dock finns det mycket kvar att göra gällande andra aspekter som också berör potentialen.

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Kauertz, Sebastian. "Beeinflussung des Wirbelnachlaufs eines Tragflügels mit aktiven winglets /." Aachen : Shaker, 2006. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=016032698&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.

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Muñoz, Hernán Darío Cerón. "Análise experimental das características aerodinâmicas de multi-winglets adaptativas." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/18/18135/tde-28102015-155234/.

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O objetivo desta pesquisa é o estudo do uso potencial de multi-winglets adaptativas para obter reduções no arrasto induzido através da variação do diedro das winglets. Os vórtices gerados nas pontas das asas são um produto inevitável da presença da sustentação, ou seja, é um custo a pagar pela força que mantém as aeronaves no ar. Diferentes estudos têm demonstrado que o escoamento presente nas pontas das asas pode ser redirecionado usando pequenas superfícies aerodinâmicas reduzindo assim o arrasto induzido. O modelo testado era constituído por uma asa retangular construída a partir de um perfil NACA 653 - 018 dotado de três winglets tipo \"tip-sails\", que são pequenas asas sem enflechamento ao 25% da corda. Os testes realizados foram para um regime de Número de Reynolds de 357.000. Os resultados foram analisados através da análise da sustentação, arrasto e mapeamento da esteira através da técnica de anemometria de fio quente.
The aim of this research is the study of the potential use of adaptive multi-winglets to reduce induced drag through variations of winglet cant angles. The vortices generated at the wing tips are an inevitable product of the presence of lift, that is, they represent the price paid for the presence for the force that keeps the aircraft in the air. Different studies have shown that the flow over the wing-tip can be redirected using small aerodynamics surfaces, thereby reducing the induced drag. The model tested is composed of a rectangular wing using a NACA 653 - 018 profile with three winglets called \"tip-sails\", which are small wings without sweep at 25% chord. The tests were made at a Reynolds number of 350,000. The results are analyzed in terms of lift and drag and mapping of the wake using hot wire anemometry techniques.

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Rosescu, Justin J. "A Study of the Design of Adaptive Camber Winglets." DigitalCommons@CalPoly, 2020. https://digitalcommons.calpoly.edu/theses/2177.

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A numerical study was conducted to determine the effect of changing the camber of a winglet on the efficiency of a wing in two distinct flight conditions. Camber was altered via a simple plain flap deflection in the winglet, which produced a constant camber change over the winglet span. Hinge points were located at 20%, 50% and 80% of the chord and the trailing edge was deflected between -5° and +5°. Analysis was performed using a combination of three-dimensional vortex lattice method and two-dimensional panel method to obtain aerodynamic forces for the entire wing, based on different winglet camber configurations. This method was validated against high-fidelity steady Reynolds Averaged Navier-Stokes simulations to determine the accuracy of these methods. It was determined that any winglet flap deflections increased induced drag and parasitic drag, thus decreasing efficiency for steady level flight conditions. Positive winglet flap deflection at higher lift conditions may increase efficiency, but the validity of the vortex lattice method results for these conditions are dubious. A high-fidelity method should be used for the high lift condition to obtain accurate efficiency data.

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Broomfield, Susannah Elizabeth. "Large deflection, nonlinear loads analysis, with application to large winglets." Thesis, University of Bristol, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492476.

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The inclusion of static aeroelastic effects is essential to the accurate calculation of the aerodynamic properties of a wing, the resulting wing loads, and ultimately the mass of the wing. Within an industrial aircraft design cycle, the computational time required for structurally coupled nonlinear flow solvers is impractical for the many different solutions required, even with the current development in computing power. The process currently used by most civilian aircraft manufacturers therefore makes use of time efficient linear panel methods for calculating the aerodynamics and modal data for calculating structural movements.University of Bristol.

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Kauertz, Sebastian [Verfasser]. "Beeinflussung des Wirbelnachlaufs eines Tragflügels mit aktiven Winglets / Sebastian Kauertz." Aachen : Shaker, 2006. http://d-nb.info/1166514803/34.

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Junior, Sergio Luiz Lousada. "Análise comparativa de winglets em uma aeronave regional de última geração." Instituto Tecnológico de Aeronáutica, 2011. http://www.bd.bibl.ita.br/tde_busca/arquivo.php?codArquivo=3023.

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O presente trabalho visa determinar, via análises de dados de túnel de vento, o impacto aerodinâmico em arrasto da instalação de dispositivos de ponta de asa em uma aeronave transônica de transporte moderna, para averiguar o ganho atingido com os atuais métodos de projeto de winglets. São comparados 3 dispositivos de ponta de asa, em uma campanha de ensaios em túnel. Os ensaios foram realizados à pressão total constante, fazendo o uso dos mesmos suportes, e realizando as mesmas variações no escoamento. Os dados colhidos em diversas rodadas de túnel foram então analisados procurando estabelecer qual a influência de cada dispositivo sob o arrasto da aeronave, em regimes subsônicos e transônicos. As comparações puderam estabelecer que o atual estado da arte oferece reduções significativas de arrasto em cruzeiro, proporcionando melhorias no alcance e outras características de desempenho da aeronave, vindo a comprovar a teoria e os dados históricos de desempenho destes dispositivos.

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Rajendran, Saravanan. "Design of Parametric Winglets and Wing tip devices : A Conceptual Design Approach." Thesis, Linköpings universitet, Fluida och mekatroniska system, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-80721.

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Winglets being a small structure play an important role in reducing the induced drag in aircraft. Many types of winglets have been designed and their significance in reducing the drag is published. One of the main objectives of this master thesis work is to study about the winglet design and about their contribution in reducing induced drag. A brief overview of wing tip devices and their performance from the manufacturers as well as from airliner’s point of view are discussed. Moreover, the role of winglet in reducing the drag of commercial civil jet aircraft is studied and the percentage of drag reduction is calculated by a conceptual approach. A320 specifications are taken to perform induced drag reduction calculation with and without winglets. Indeed, the total drag count reduced with the help of winglets accounts for additional payload which will be an advantage for the aircraft operator. Reducing the process time in design is one of the important criteria for any field and hence automation with help of CAD tools is very significant in reducing time. This study also aims at developing an automated model for different types of winglets and wing tip devices with the help of CAD technology focused on reducing design time during the initial design process. Knowledge based approach is used in this work and all the models are parameterized so each model could be varied with associated parameters. The generic model created would take different shapes and switches between different types of wing tip devices as per the user’s requirement with the help of available parameters. Knowledge Pattern (KP) approach is used to develop the automation process. User Defined Features (UDFs) are created for each type of winglet and tip devices. CATIA V5 R18 software is used to develop the models of winglets and tip devices.

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Lawson, Michael James. "Practical Applications of Delta Winglets in Compact Heat Exchangers with Louvered Fins." Thesis, Virginia Tech, 2006. http://hdl.handle.net/10919/34141.

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Compact heat exchangers are widely used by the automotive industry in systems that cool engine components. Louvered fin heat exchangers are used over their continuous fin counterparts because of the significant advantages they provide in heat transfer efficiency, while only causing small increases in overall pressure losses. With the recent emphasis that has been placed on reducing fuel consumption, decreasing the size of the compact heat exchanger has become an important concern. With reduction in size comes not only weight savings, but also a decrease in frontal area in a vehicle that must be dedicated to the heat exchanger, allowing for more aerodynamic vehicle designs.

Air-side resistance on the tube wall and louvered fin surfaces comprises over 85% of total resistance to heat transfer in louvered fin heat exchangers. The tube wall surface is considered the primary surface for heat transfer, where the temperature between the working fluid and convecting air is at a maximum. Recent studies have shown that implementing delta winglets on louvered fins along the tube wall is an effective method of augmenting tube wall heat transfer. In this thesis, the effect of delta winglets is investigated in both two- and three-dimensional louvered fin arrays. For both geometries, winglets are simulated in a manufacturable configuration, where piercings in the louvered fins that would result from the winglet manufacturing process are modeled.

Using the two-dimensional geometry to model tube wall heat transfer was shown not to accurately predict heat transfer coefficients. In a two-dimensional geometry, winglets were found not to be an effective means for augmenting tube wall heat transfer and caused only 8% augmentation. Using the three-dimensional geometry, winglets with simulated piercings were observed to cause up to 24% tube wall heat transfer augmentation, with a corresponding increase in pressure losses of only 10%.

Master of Science

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Farhan, Ali M. "Numerical study of the effect of winglets on a horizontal axis wind turbine performance." Thesis, University of Leeds, 2018. http://etheses.whiterose.ac.uk/22493/.

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With increasing demand for producing clean and pollution free energy, special attention has been paid to wind turbines and improving their performance. Reducing the effect of wingtip vortices on the wind turbine performance can be achieved by using winglets which work to weaken the impact of wingtip vortices by diffusing them away from the blade tips. The general trend of the literature has considered winglets as diffusers of the wingtip vortices. However, extending the span of the turbine rotor by attaching winglet could improve the potential of a rotor to capture more kinetic energy from moving air. Accordingly, the winglet planform and airfoil play vital roles in wind turbines performance. The present work reports on the study of the effect of winglet planform and winglet airfoil on the wind turbine performance using Computational Fluid Dynamics (CFD) tools. The National Renewable Energy Laboratory (NREL) phase VI rotor is used as a baseline rotor and the CFD results are validated with the experimental data in terms of torque, pressure and normal force coefficients for different wind speeds. In this study, two turbulence models are used, which are the SST k-ω and the Spalart-Allmaras models, which can be used to predict the properties of the fluid flow in the computational domain. Both of the models show a good match of the numerical results when compared to the experimental data, at a range of low wind speeds from 5m/s to 8m/s, due to the absence of stalled flow. At higher wind speeds of 10m/s, the SST k-ω model shows a better match between the calculated torque and the experimental measurements. Consequentially, the SST k-ω model is implemented to predict the behaviour of fluid flow in all the CFD calculations in the present study. The aerodynamic behaviour of two winglet planforms is investigated. These are rectangular and elliptical winglets to increase the NREL phase VI rotor performance. The performances of four winglet configurations are assessed when compared to the baseline power, at the range of wind speeds from 5m/s to 25m/s. The configurations are obtained by changing the winglet planforms and airfoils using the S809 and PSU 94-097 airfoils. In this regard, the elliptical planform causes a minimizing of the wingtip vortices, more than the rectangular planform, due to the reduction of the elliptical tip by 75% when compared to the rectangular tip. A rectangular planform shows a better performance than the elliptical planform in percentages of power increase. The highest percentage in the power increase is achieved by attaching the rectangular planform that tilted by a cant angle of 45o and extended by 15cm. This improvement is slightly more than 9%, at the range of low wind speeds from 5m/s to 10m/s, since the flow is almost attached. Considering the effect of winglet airfoil, the study reports that, choosing a suitable winglet airfoil is mainly dependent on the aerodynamic coefficients of the selected airfoil, such as lift coefficient (Cl), drag coefficient (Cd) and moment coefficient (Cm). For this purpose, a preliminary analysis is conducted using the Xfoil code to predict the aerodynamic coefficients of selected airfoils (S801, S803, S805A and S806A airfoils). The S806A and S805A airfoils are chosen to create two different configurations. The 3D calculations show more increase in the NREL phase VI power is achieved by attaching the configuration that created using the S806A airfoil since this airfoil has less drag coefficient.

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Dezan, Daniel Jonas. "Intensificação da transferência de calor e otimização de trocadores de calor compactos tipo venezianas com geradores de vórtices tipo delta-winglets." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/3/3150/tde-17062016-143657/.

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Esta pesquisa visa a análise da contribuição de cinco variáveis de entrada e a otimização do desempenho termo-hidráulico de trocadores de calor com venezianas combinados com geradores de vórtices delta-winglets. O desempenho termohidráulico de duas geometrias distintas, aqui nomeadas por GEO1 e GEO2, foram avaliadas. Smoothing Spline ANOVA foi usado para avaliar a contribuição dos parâmetros de entrada na transferência de calor e perda de carga. Considerando aplicação automotiva, foram investigados números de Reynolds iguais a 120 e 240, baseados no diâmetro hidráulico. Os resultados indicaram que o ângulo de venezianas é o maior contribuidor para o aumento do fator de atrito para GEO1 e GEO2, para ambos os números de Reynolds. Para o número de Reynolds menor, o parâmetro mais importante em termos de transferência de calor foi o ângulo das venezianas para ambas as geometrias. Para o número de Reynolds maior, o ângulo de ataque dos geradores de vórtices posicionados na primeira fileira é o maior contribuidor para a tranfesferência de calor, no caso da geometria GEO1, enquanto que o ângulo de ataque dos geradores de vórtices na primeira fileira foi tão importante quanto os ângulos das venezianas para a geometria GEO2. Embora as geometrias analisadas possam ser consideradas como técnicas compostas de intensificação da transferência de calor, não foram observadas interações relevantes entre ângulo de venezianas e parâmetros dos geradores de vórtices. O processo de otimização usa NSGA-II (Non-Dominated Sorting Genetic Algorithm) combinado com redes neurais artificiais. Os resultados mostraram que a adição dos geradores de vórtices em GEO1 aumentaram a transferência de calor em 21% e 23% com aumentos na perda de carga iguais a 24,66% e 36,67% para o menor e maior números de Reynolds, respectivamente. Para GEO2, a transferência de calor aumentou 13% e 15% com aumento na perda de carga de 20,33% e 23,70%, para o menor e maior número de Reynolds, respectivamente. As soluções otimizadas para o fator de Colburn mostraram que a transferência de calor atrás da primeira e da segunda fileiras de geradores de vórtices tem a mesma ordem de magnitude para ambos os números de Reynolds. Os padrões de escoamento e as características de transferência de calor das soluções otimizadas apresentaram comportamentos vi particulares, diferentemente daqueles encontrados quando as duas técnicas de intensificação de transferência de calor são aplicadas separadamente.
This doctoral thesis focuses on screening analysis of five input parameters and heat transfer and pressure drop optimization of flat-tube multi-louvered fin heat exchangers combined with delta-winglet vortex generators. The thermal-hydraulic performance of two distinct geometries, GEO1 and GEO2, were evaluated. Smoothing Spline ANOVA was used to evaluate the contribution of the input parameters such as louver angle, angle of attack of the delta-winglet and streamwise position of the delta-winglet on heat transfer and pressure drop. Taking the automotive application into account, Reynolds numbers of 120 and 240, based on hydraulic diameter, were investigated. The results indicated that the louver angle is the main contributor to increase the Friction factor for GEO1 and GEO2 for both Reynolds numbers. For the lower Reynolds number, the most important heat transfer parameter was the louver angle for both geometries, while at the higher Reynolds number, the angles of attack of the first row of delta-winglets mostly contributed to GEO1, and the angle of attack of the first row of delta-winglets was as important as the louver angle for GEO2. Although those specific geometries can be considered a kind of compound enhancement technique, relevant interactions were not verified between louvers and delta-winglet vortex generators parameters. The surrogatebased optimization procedure uses NSGA-II method (Non-Dominated Sorting Genetic Algorithm) combined with artificial neural networks. The results showed that the addition of DWLs on GEO1 increased the heat transfer of 21.27% and 23.52% with associated pressure loss increasing of 24.66% and 36.67% for the lower and the higher Reynolds numbers, respectively. For GEO2, the heat transfer was increased 13.48% and 15.67% with an increase of the pressure drop of 20.33% and 23.70%, for the lower and the higher Reynolds numbers, respectively. The optimized solutions for the Colburn factor showed that heat transfer behind the second row of deltawinglets has the same order of magnitude of that behind the first row, for both Reynolds numbers. The flow patterns and heat transfer characteristics from optimized solutions presented some particular behavior, differently from the findings when those two heat transfer enhancement techniques are applied separately.

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Berglund, Tobias. "Evaluation of Fuel Saving for an Airline." Thesis, Mälardalen University, Department of Mathematics and Physics, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-586.

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A study of which methods and measures that can be used to reduce fuel consumption and harmful discharges in an airline.

The study begins with an investigation containing calculations of the differences between estimated fuel consumption calculated by a computer program called Skytrack and actual fuel consumption. Results from this study allows synchronization between actual consumption with calculated consumption. In addition to this methods and configurations to reduce weight and thus weight onboard aircrafts e.g. carpet exchange, lightweight trolleys and water reduction has been created and analysed.

To bring the thesis to an end, the author has investigated other methods and configurations which TUIfly Nordic is implementing for fuel conservation.

The thesis results in several conceivable areas for fuel conservation with calculated savings of 830 000 EUR which for the moment is implemented in TUIFly Nordic.

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GongZhang, Hanlin, and Eric Axtelius. "Aircraft Winglet Design." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-276586.

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Aerodynamic drag can be decreased with respect to a wing’s geometry, and wingtip devices, so called winglets, play a vital role in wing design. The focus has been laid on studying the lift and drag forces generated by merging various winglet designs with a constrained aircraft wing. By using computational fluid dynamic (CFD) simulations alongside wind tunnel testing of scaled down 3D-printed models, one can evaluate such forces and determine each respective winglet’s contribution to the total lift and drag forces of the wing. At last, the efficiency of the wing was furtherly determined by evaluating its lift-to-drag ratios with the obtained lift and drag forces. The result from this study showed that the overall efficiency of the wing varied depending on the winglet design, with some designs noticeable more efficient than others according to the CFD-simulations. The shark fin-alike winglet was overall the most efficient design, followed shortly by the famous blended design found in many mid-sized airliners. The worst performing designs were surprisingly the fenced and spiroid designs, which had efficiencies on par with the wing without winglet.
Det aerodynamiska luftmotståndet kan minskas genom justeringar i vingens geometri, och vingtipsenheter så kallade virveldämpare spelar en vital roll inom vingdesign och utveckling. Projektet hade fokuset på att undersöka de lyft -och motståndskrafterna som genererades av en förutbestämd vinge vid användandet av olika varianter av virveldämpare. Genom beräkningsströmningsdynamiska simuleringar (CFD) och vindtunneltester av nerskalade 3D-utskrivna modeller kan dessa krafter beräknas. Med hjälp av dessa kan respektive virveldämparens bidrag till de sammanlagda lyft -och motståndskrafterna på vingen vidare bestämmas. Genom att beräkna förhållandet mellan de erhållna lyft -och motståndskrafterna kan vingens glidtal sist bestämmas, som är ett dimensionslöst mått på vingens effektivitet. Resultatet från denna studie visade att vingens prestanda varierade efter på valet av virveldämpare, där vissa designer gav avsevärda förbättringar över andra enligt CFD-simuleringar. Den hajfensliknande varianten (så kallad sharklet på engelska) var den mest effektiva designen, tätt följt av den ordinära uppåtriktade typen (blended på engelska) som återfinns på många av dagens medelstora flygplan. De sämst presterande designerna var förvånande nog den triangel -och spiralformade (fenced och spiroid på engelska), vilka presterade på samma nivå som den virveldämparfria vingen.

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Gagliardi, M. "Endocytosis and wingless signalling." Thesis, University College London (University of London), 2012. http://discovery.ucl.ac.uk/1353109/.

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Wingless (Drosophila Wnt-1) is secreted glycoprotein that triggers an evolutionary conserved signal transduction pathway. The role of endocytosis in Wnt/Wingless signaling is not clearly understood and highly debated. In my thesis I explore the role that endocytosis/endocytic trafficking has on Wingless signalling activation and termination. In the canonical pathway Wingless binds to a member of the Frizzled family of seven-pass transmembrane receptor (Frizzled1 or Frizzled2) and to Arrow. Formation of this trimeric complex leads to the inactivation of the Armadillo degradation complex and translocation of Armadillo into the nucleus where it contributes to the activation of target genes. I show that internalization of the ligand-receptor complex is not required for signalling activation. I also show that Wingless has different effects on the trafficking route of its receptors: it induces the degradation of Frizzled2 and the recycling of Arrow. To identify post translational modifications that regulate Arrow trafficking I conducted an RNAi screen in Drosophila S2R+ cells for de-ubiquitylating enzymes (DUBs) and ubiquitin conjugating enzymes (E2) that modulate signalling. To carry out this screen, improvements on the current TOPFlash Wnt/Wingless signalling reporter were made. I also directly assessed the role of endocytic trafficking on signalling using a chemical inhibitor of endocytosis, Dynasore. I find that Dynasore inhibits signalling by causing a strong decrease in Armadillo levels. Future experiments will determine whether it is the stability or the rate of production of Armadillo that is affected.

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Owen, Louise Elaine. "A structure/function analysis of the wingless gene and the wingless protein of Drosophila melanogaster." Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361451.

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Marshall, Francis James. "Wingless degradation in Drosophila imaginal discs." Thesis, University College London (University of London), 2006. http://discovery.ucl.ac.uk/1444851/.

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Wingless is a secreted signalling molecule with multiple roles in patterning developing Drosophila. Previous work has shown that in the Drosophila embryonic epidermis, regulated degradation controls the distribution of Wingless protein, leading to an asymmetric range. The actual mechanism of Wingless degradation is not currently understood. I have used gain and loss of function experiments to examine the role of the signalling receptors, Dffizzled-2 and Arrow, in the control of Wingless degradation. Receptor mediated degradation can be subdivided into three steps: capture, endocytosis and targeting to lysosomes. Dfrizzled-2 is understood to play a key role in capture and indeed when Dfrizzled-2 is overexpressed, Wingless is stabilised at the cell surface. I have shown that Wingless and Dfrizzled-2 also colocalise in endocytic structures and by using mutants of Dfrizzled-2,1 have shown that Dfrizzled-2 is actively involved in the endocytosis of Wingless. Dfrizzled-2 therefore appears to function in the first two steps towards degradation, capture and endocytosis, however it is clearly not sufficient for degradation as when overexpressed, Dfrizzled-2 stabilises Wingless. This suggests that a limiting factor is absent that prevents Wingless captured by DFrizzled-2 from being degraded. I investigated the possibility that this limiting factor could be Arrow. I have shown that indeed, Arrow brings about the degradation of the Dfrizzled-2-Wingless complex. This activity is specific to Dfrizzled-2, since Arrow does not cause degradation of Wingless stabilised by Dally-like, another Wingless receptor. My results have led to a model where there is a division of labour between the two signalling receptors Dfrizzled-2 has functions in capture and endocytosis and Arrow, while also contributing somewhat to endocytosis, brings the signal that directs Wingless to lysosomes. Further investigations have been carried out to identify the specific motifs in Arrow that target Wingless to degradation.

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Koutník, Tomáš. "Návrh wingletu pro kluzák LS-3." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229455.

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This diploma thesis describes the design of winglets for LS-3 glider. The method for determination of main winglet parameters based on selected criterion is presented as well as comparation of performace of original wing and final modification. It also includes analysis of wing loading and resetting of speed and weight limits for flying with winglets.

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Yu, Xiang. "Wingless signal transduction during Drosophila embryonic development." Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.624339.

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Tang, Xiaofang. "Regulation of Wingless secretion, distribution and signaling." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1353100929.

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Hanson, K. K. "Regulation of Wingless signaling and mitosis in Drosophila." Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.603670.

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In order to identify new regulators of the Wg signaling pathway, others in the Bienz laboratory carried out an EMS screen to find modifiers of the phenotype caused by expression of a stable Armadillo transgene in the Drosophila eye. I proceeded with the characterization of a number of mutants that resulted from this screen, and identified one enhancing complementation group as alleles of sine oculis (so). So is a homeodomain containing protein, chiefly characterized as a member of the retinal gene determination network, a group of transcription factors that direct eye development. I identified genetic interactions between so and the Wg pathway in several tissues, and identified a Wg target gene, senseless, which can be co-regulated by so. Furthermore, I discovered that So is capable of inducing morphogenesis in the wing disc, a finding which may have relevance to the role of so in physiological induction of the morphogenetic furrow in the eye disc. I also characterized another lethal hit present, in addition to the mutant so allele, on one of the modifying chromosomes isolated in the screen. I mapped and cloned this gene, and identified the Drosophila orthologue of borealin (borr), a recently discovered 4^th member of the Chromosomal Passenger Complex (CPC). The CPC regulates a number of events during mitosis by controlling the localization and activity of Aurora B kinase, a CPC member. I found that borr is an essential gene, and that loss of borr results in multiple mitotic defects indicative of a loss of CPC activity. I determined that Borealin colocalizes with other CPC proteins at mitotic spindles, and furthermore that borr is required for their localization.

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Pfeiffer, Sven. "Wingless transport in the embryonic epidermis of drosophila." Thesis, University College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248103.

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Baker, N. E. "Wingless : A gene required for segmentation in Drosophila." Thesis, University of Cambridge, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377244.

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Fang, Hsiao Yu. "Role of wingless signalling in Drosophila midgut homeostasis." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708814.

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Palmer, L. R. "The route taken by Wingless in secreting cells." Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1447572/.

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Wingless (Wg), the major Drosophila Wnt, contributes to patterning, growth and cell survival during development. Wg is produced in a stripe at the dorsal-ventral boundary of the wing imaginal disc, a pseudostratified epithelium. Whole mount staining of permeabilised discs reveal that the Wg protein is tightly localized in the apical region of secreting cells. By contrast, extracellular Wg is barely detectable at the apical surface. Instead, extracellular Wg is mostly found at the basolateral surface of secreting, as well as surrounding, cells. These observations suggest that, in secreting cells, apically produced Wg traffics to the basolateral surface for release and gradient formation. This possibility has not been formally investigated. Nevertheless, specific regulators of Wg secretion have been identified. For example, Wntless (Wls)/Evenness interrupted (Evi) binds Wg in the ER and transports it to the plasma membrane. Without Evi, Wg accumulates within the secretory pathway. To test the transcytosis model, I have designed means of tracking Evi and Wg in secreting cells, using classical secretory and endocytic markers as guideposts. I have constructed tagged versions of Wg and Evi, which rescue wg or evi mutants when expressed at an endogenous level. In one set of experiments, I have produced a step of Wg expression and fixed discs at subsequent time points. With this approach I have determined that Wg moves from its apical production site towards the basolateral surface. This was confirmed with experiments utilising a temperature-sensitive dynamin mutant (shibirets) to control endocytosis. With this genetic tool, I have obtained data suggesting that Evi too transits through the apical surface of expressing cells before progressing basally. Unlike Wg, Evi is not released at the basolateral surface. I suggest that instead, it is recycled to replenish the secretory pathway, where it can escort more Wg to the apical surface.

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Zemzami, Amin. "Analisi computazionale preliminare di una winglet non-convenzionale." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/19122/.

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L'obiettivo di questo studio è sviluppare e valutare dal punto di vista prettamente aerodinamico, mediante metodi computazionali, una winglet a doppia estremità (up & down). Per lo sviluppo e l'ottimizzazione sono stati presi come riferimento i risultati ottenuti tramite il software xflr5 (metodo Vortex Lattice), mentre lo studio finale, nel confronto con la stessa ala senza winglet, è stato effettuato utilizzando SolidWorks Flow Simulation (analisi CFD). Ciò che si vuole dimostrare è che una winglet costruita in questo modo può, in linea generale, avere effetti benefici sulle prestazioni aerodinamiche. Questo tenendo conto, anzitutto, che un eventuale studio degli effetti generati sulla struttura alare diminuirebbe l'entità di questi benefici, ma, d'altra parte, le semplificazioni effettuate portano a pensare che esistano margini di miglioramento rispetto alla configurazione valutata.

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Brennan, K. "The function of the notch protein in wingless signalling." Thesis, University of Cambridge, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.596884.

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The Notch gene of Drosophila melanogaster encodes a large, single span transmembrane protein. Work over the past years has shown that this functions as a receptor protein for the closely related signalling proteins, Delta and Serrate, and that this function has been conserved during evolution. However examination of the structure of Notch protein and its homologues has indicated that much more of the protein is conserved between species than the regions required for the Notch to function in the Delta and Serrate signalling pathways. Also physical mapping of mutations shows that altering the structure of the Notch protein outside the regions required for it to function in Delta and Serrate signalling can profoundly affect the function of the protein. One possible explanation for the conservation of the protein in these regions is that the Notch protein interacts with a number of other extracellular signalling proteins and is involved in other signalling pathways. This would also explain differences in the mutant phenotype of Drosophila embryos that lack the Notch protein and embryos in which Delta and Serrate signalling is disrupted. Genetic experiments have suggested that one of these other signalling molecules may be the Wingless protein, a member of WNT superfamily, because of a strong interaction between the Notch and wingless genes. It is this possibility that I have examined in this thesis. As a consequence of my experiments, I am presenting evidence in this thesis: that the Notch protein has a function that is distinct from its role in Delta and Serrate signalling; that this previously undiscovered function of the Notch protein is dependent upon the Shaggy protein; that the Wingless and Notch proteins interact both in vitro and in vivo; and finally that disruption Notch function can interfere with the ability of the Wingless protein to signal.

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Ng, Medard Hein Tsoeng. "Genetic and molecular analyses of nubbin, a gene involved in proximal-distal patterning of the Drosophila wing." Thesis, Open University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309862.

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Pinto, Fernando Antônio Fialho. "Estudo dos parâmetros aerodinâmicos do winglet em aeronaves comerciais." Instituto Tecnológico de Aeronáutica, 2004. http://www.bd.bibl.ita.br/tde_busca/arquivo.php?codArquivo=659.

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Fomentados pelas centenas de dólares gastos anualmente pelas linhas aéreas em combustíveis, diversos estudos foram e continuam sendo realizados visando reduzir o consumo das aeronaves. Desde as primeiras aeronaves a jato de transporte civil atée a atualidade estima-se que a redução de combustível alcançou o índice de 70%, dos quais 30% estão diretamente relacionados à evolução tecnológica no projeto dessas aeronaves e, os 40% restantes, à melhora da eficiência dos motores. Uma alternativa de projeto identificada para este fim consiste no uso de dispositivos de ponta de asa, tais como o Winglet para possibilitar às aeronaves voar mais alto, consumir menos combustível ou mesmo voar mais rápido, além de melhorar a sua performance de decolagem e subida, reduzindo, assim, o ruído externo emitido à população que vive na região próxima dos aeroportos. Contudo o preço pago por essa melhoria envolve aumentos nos custos de fabricação e manutenção, pesos vazios maiores, além de um aumento nos custos que envolvem o estudo da estabilidade e controle das aeronaves. Com o objetivo de fornecer ao leitor aspectos aerodinâmicos práticos e teóricos que envolvem o uso do winglet este trabalho foi dividido em quatro etapas, caracterízadas pelas seguintes ações: realizar uma extensa revisão bibliográfica; implementar e validar um programa de cálculo aerodinâmico de asas, baseado no método de Weissinger ou método da linha sustentadora estendido; desempenhar, com este programa, um estudo aerodinâmico dos parâmetros geométricos do winglet; e por fim, simular um estudo de caso, avaliando as vantagens obtidas com o uso dos winglets na performance de uma aeronave militar de patrulha. Nos estudos comprovou-se a competência do método para uso no estudo preliminar dos parâmetros geométricos do winglet

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Hutchinson, Lisa. "Biochemical analysis of components of the wingless/WNT signalling pathway." Thesis, Institute of Cancer Research (University Of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.395976.

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Ricardo, Sara Franco. "Release and transport of the secreted signal encoded by wingless." Thesis, University College London (University of London), 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.407058.

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Tan, Joo Lee Denise. "An analysis of protein localization dynamics during Wnt/Wingless signaling." Thesis, University of Cambridge, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.612188.

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32

Malinowski, Matěj. "Aerodynamická analýza měnitelné geometrie wingletu pro aplikaci na výkonném kluzáku." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-318705.

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Diplomová práce se zabývá aerodynamickou analýzou a optimalizací wingletu kluzáku. Winglet je uvažován s možností změny tvaru v průběhu letu a optimalizační proces je zaměřen na odhalení optimálních tvarů v odlišných letových režimech. První část práce popisuje současné snahy v oblasti návrhu a vývoje wingletů s měnitelnou geometrií. Druhá část je zaměřena na popis funkce wingletu, následována třetí částí, která popisuje optimalizační metody, které mohou být použity během optimalizace. Další částí práce je popis letadla vybaveného wingletem, který byl vybrán pro optimalizaci. Tato část je následována požadavky stavebního předpisu kategorie letadla, které bylo vybráno. Následuje model typického letu tohoto letadla. Zbytek práce je organizován dle procesu hledání optimálních tvarů wingletu. Popis tvorby CAD modelu je následován popisem tvorby CFD modelu a popisem přípravy CDF simulací. V předposlední kapitole jsou odhaleny detaily optimalizačního procesu. Závěrečná část práce obsahuje vyhodnocení výsledků optimalizačního procesu.

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Schumacher, Alexander, Erik Sjögren, and Tobias Persson. "Winglet Effect on Induced Drag for a Cessna 172 Wing." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-152908.

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The perfect wing is a dream that many airplane manufactures have been striving to achieve since the beginning of the airplane. The goals are usually the same for everyone; - Increase lift - Reduce drag - Minimize weight A combination of these goals lead to a decrease in fuel consumption, which in turn reduces pollution in our atmosphere with the added bonus of an increase in economic revenue. One way to improve performance is to modify the tip of the wing structure, which has become a common sight on today’s airplanes. With the help of computational programs, the effects on drag due to wingtip devices can be previewed.

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Gieseler, Katherin. "DWnt4 : un nouveau gène Wnt de drosophile au locus de Wingless." Aix-Marseille 2, 1997. http://www.theses.fr/1997AIX22024.

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Les proteines codees par les genes wnt sont des molecules signal, secretees, impliquees dans l'adressage cellulaire au cours de nombreux processus developpementaux. Elles sont conservees dans tout le regne animal, et toute perturbation de l'activite d'un gene wnt est un exemple de catastrophe developpementale. Aujourd'hui, un grand nombre de genes wnt sont clones dans differentes especes, de la drosophile a l'homme. Chez la drosophile, trois genes wnt ont ete identifies: wingless (wg), l'homologue du proto-oncogene wntl de la souris, dwnt2 et dwnt3, respectivement homologues des genes wnt7 et wnt5 de la souris. Lors de la recherche des genes cibles de la proteine homeotique ultrabithorax, nous avons isole le gene dwnt4 un nouveau membre de la famille wnt. Dwnt4, presente la particularite d'etre situe au meme locus cytogenetique que wg. Au cours de l'embryogenese et dans les disques imaginaux, les precurseurs des structures adultes, les patrons d'expression de wg et de dwnt4 sont partiellement chevauchants. Dans les cellules de l'ectoderme ventral et du mesoderme visceral, qui co-expriment les deux genes, leur transcription depend des memes mecanismes de regulation. Des experiences d'injection dans l'embryon d'arn complementaire a l'arn messager de dwnt4, ont montre que dwnt4 pouvait avoir une fonction dans la differenciation de l'ectoderme et que cette fonction est opposee, mais complementaire a celle de wg. Pour etudier plus avant la relation fonctionnelle entre wg et dwnt4, nous avons analyse l'effet de la surexpression de ce dernier dans l'embryon de xenopus laevis. Nos resultats indiquent que dans ces conditions, dwnt4 est capable d'antagoniser l'activite de wg. De meme, l'expression dirigee de dwnt4 dans l'embryon de drosophila melanogaster, bloque la fonction tardive de wg dans la differenciation de l'ectoderme. L'expression ectopique de dwnt4 suivant la frontiere compartimentale antero-posterieure des disques imaginaux provoque une duplication de structures adultes. Celle-ci resulte d'une reprogrammation genetique des cellules du disque imaginal induite par le signal ectopique dwnt4. Ce dernier n'exerce alors pas de fonction antagoniste a celle de wg ; au contraire, les phenotypes provoques dans un contexte deficient pour wg indiquent que dwnt4 peut complementer cette perte de fonction

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Intaratep, Nanyaporn. "The Investigation of an Inboard-Winglet Application to a Roadable Aircraft." Thesis, Virginia Tech, 2002. http://hdl.handle.net/10919/33519.

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The inboard-winglet concept was examined for its flow characteristics by testing for pressure coefficients over the wing and winglet surface in the Virginia Tech Stability Wind Tunnel over a range of freestream velocity and angle of attack. The results were analytically applied to calculate aircraft performance of a roadable aircraft, Pegasus II, which used the inboard-winglet concept in its design. The results proved that this concept has the potential to increase a wing lift coefficient at the right combination of thrust setting and freestream velocity better than a conventional wing-propeller arrangement. The lift coefficient inside the winglet channel was approximated as 2D in behavior. It is also shown that the winglets produce thrust at a positive-lift wing configuration. In the Pegasus II, the vertical stabilizers act like inboard winglets and produce a thrust component from its resultant force, giving 5.2% improvement in its effective aspect ratio and resulting in an induced-drag decrease. With an application of the new wing concept, the Pegasus II performance is comparable to other general aviation aircraft.
Master of Science

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36

Lawrence, Nicola Jane. "A role for repression in the wingless signalling pathway in Drosophila melanogaster." Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621286.

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Izquierdo, David Orlando Diaz. "Análise experimental do efeito aerodinâmico de dispositivos de asa e ponta de asa em uma aeronave tipo \"Blended Wing Body\"." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/18/18148/tde-26072016-104731/.

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Este trabalho tem por objetivo analisar o comportamento aerodinâmico de dispositivos de ponta de asa e Fences acoplados em uma aeronave Blended Wing Body (BWB) através de testes em túnel de vento. A BWB é um projeto de aeronave alternativo que faz parte do conceito de aeronaves sustentáveis. O Laboratório de Aeronaves da Escola de Engenharia de São Carlos, Universidade de São Paulo, vem realizando uma série de pesquisas sobre este assunto. Em trabalhos anteriores com o modelo BWB foram observados a presença tanto de um escoamento transversal na parte externa quanto um forte vórtice no meio do modelo. A fim de melhorar o primeiro protótipo o Droop, bem como um arranjo de três Fences foram adicionados no modelo BWB. Além disso, os dispositivos Winglets e C-wing foram considerados neste estudo. Entre o desenvolvimento de aeronaves, vários dispositivos têm sido estudados e implementados em aeronaves convencionais. Estes tem várias vantagens, tais como a melhoria da eficiência aerodinâmica e a redução do arrasto induzido e efeitos positivos no rendimento do avião. Os dispositivos de ponta da asa criam uma força aerodinâmica em que um do seus componentes atua na direção do voo, esta também pode contribuir para a redução da intensidade dos vórtices nas pontas da asa, reduzindo o arrasto induzido. Pesquisas em aeronaves não convencionais mostraram que BWB poderia ter melhores características aerodinâmicas do que uma aeronave convencional. Aindústriaaeronáuticaestáprocurandoareduçãodoscustosoperacionais,bemcomo a adaptação das aeronaves para a restrição legislativa das emissões de gases e poluição sonora. Nas últimas décadas, esta redução não teve uma melhora significativa em termos de valores absolutos para configurações convencionais, isso fez com que novas e mais eficientes configurações têm sido estudadas. A interferência dos diferentes dispositivos no modelo BWB foram analisados em teste em túnel de vento. Os experimentos foram realizados no Laboratório de Aeronaves da Escola de Engenharia de São Carlos, Universidade de São Paulo. Foi utilizado um túnel de vento fechado com uma seção de teste de 1.7x1.3x3 [m]. O ângulo de ataque foi variado desde -4º a 20º e Re = 390.000. Os resultados mostram que os dispositivos nas pontas da asa melhoraram o desempenho da aeronave, bem como a eficiência aerodinâmica. Com relação aos Fence este comportamento não foi observado. Entre tanto, em ângulos elevados a eficiência foi aumentada. Através da técnica de visualização oil flow observou-se que o escoamento sobre a asa foi redirecionado diminuindo o coeficiente de arrasto em ângulos de ataque elevados.
This work aims to analyze the aerodynamic behavior of wingtip devices and Fences coupled on a Blended Wing Body aircraft (BWB) through wind tunnel tests. The BWB is an alternative of airship design which makes up part of the Green aircraft concept. The Aircraft Laboratory of the School of Engineering of São Carlos-University of São Paulo has been carrying out a lot of research into this subject. In previous works with a BWB model, the presence both of a cross flow on the external part and a stronger vortex in the middle of the model have been observed. In order to improve the first prototype a Droop as well as an arrangement of three Fences were added on the BWB model. Furthermore the Winglets, C-wing devices were considered in this study. Among the aircraft development, several devices have been studied and implemented in conventional aircraft. These ones had several advantages such as improving the aerodynamic efficiency and induced drag reduction and getting positive effects on aircraft performance. The wingtip devices create an aerodynamic force in which one of this components acts in the flight direction, also these can contribute to the reduction of the wingtip vortices strength, reducing the induced drag. Researches in non conventional aircraft has shown that BWB could have better aerodynamic characteristics than a conventional aircraft. The aeronautical industry is looking for the reduction of direct operational cost, as well as the adaptation of aircrafts to the demanding legislative restriction of gas emissions and noise pollution. In the last few decades this reductions has not had a significant improvement in terms of absolute values for conventional configurations, this has meant that new and more efficient configurations have been studied. The interference of the different devices on the BWB model were analyzed in wind tunnel test. The experiments were carried out in the Aircraft Laboratory of the School of Engineering of São Carlos-University of São Paulo. A closed wind tunel with a section work of 1.7x1.3x3 [m] was used. The angle of attack was varied from -4º to 20º and Re = 390.000. The results shows that the wing tip devices improved the aircraft performance as well as the aerodynamic efficiency. Regarding the Fences this behavior was not observed. However, at higher angles the efficiency was increased. Through oil flow visualization it was observed that the flow over the wing was redirected decreasing the drag coeficient at higher attack angles.

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Wenzl, Kristin [Verfasser]. "Charakterisierung des Wnt/Wingless Tumorsuppressorgens WTX im Medulloblastom und im Kleinhirn / Kristin Wenzl." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2016. http://d-nb.info/1102933309/34.

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Musisi, Hannah Kathleen Kabeyu Naggayi. "A genetic modifier screen to isolate novel components of the wingless signalling pathway." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620607.

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Sanders, Philip Gordon Thomas. "A biochemical analysis of regulatory interactions between the Notch and Wingless signalling pathways." Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.614348.

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Desbordes, Sabrina. "The role of the Drosophila glypicans in wingless and hedgehog signalling during embryogenesis." Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.615868.

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42

Hodovanic, Kelly. "Effects of retinoic acid on wingless (WNT) signaling in the hair follicles of mice." Connect to resource, 2010. http://hdl.handle.net/1811/45456.

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43

Nohynek, Dana. "Role of heparan sulfate proteoglycans in Wg activity and wingless signaling in Drosophila melanogaster." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0021/MQ54096.pdf.

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Butler, M. J. "Identification of region-specific targets of wingless signalling in Drosophila melanogaster using oligonucleotide microarrays." Thesis, University of Sussex, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.559237.

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Walters, Zoe Suzanne. "The role of the TFIIH subunit XPD in wingless signal transduction in 'Drosophila melanogaster'." Thesis, University of Sussex, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.432428.

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Cox, Virginia Taylor. "Signal transport, levels and integration : new lessons from wingless regulation of drosophila mesoderm development /." Access full-text from WCMC, 2004. http://proquest.umi.com/pqdweb?did=845726451&sid=15&Fmt=2&clientId=8424&RQT=309&VName=PQD.

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Thompson, Barry James. "The Drosophila gene pygopus encodes a new nuclear component of the wingless signalling pathway." Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.615979.

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Mehta, Abijeet S. "Novel Newt Proteins Regulate Evolutionarily Conserved Wingless Signaling Pathway to Rescue Drosophila Eye Mutants." University of Dayton / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1566599834813722.

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49

Enjolras, Camille. "Étude du gène chibby, acteur de la voie de signalisation Wnt chez les mammifères, qui est nécessaire à la maturation des centrioles en corps basaux chez Drosophila melanogaster." Thesis, Lyon 1, 2011. http://www.theses.fr/2011LYO10214.

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Les cils et flagelles sont des organites cellulaires retrouvés des protozoaires aux mammifères. Une dérégulation de l’assemblage (ciliogenèse) ou de la fonction des cils, entraîne diverses maladies chez l’homme. Parmi les acteurs de la ciliogenèse, se trouvent les facteurs de transcription RFX. La recherche de gènes cibles de RFX chez la drosophile a permis d’identifier le gène Chibby (Cby), précédemment décrit comme un antagoniste de la voie de signalisation Wnt/wingless. Contrairement aux vertébrés, chez les invertébrés aucun lien n’est encore établi entre cil et voie wg. L’identification de cby comme cible de dRFX chez la drosophile suggère une fonction ciliaire de cby et permettrait l’établissement du lien cil/voie wg. CBY se localise à la zone de transition des cils des neurones sensoriels du système nerveux périphérique et aux centrioles des spermatides. Les drosophiles invalidées pour cby présentent un phénotype de non coordination, mais aucun phénotype de type wg. Ces mutants ont des défauts des cils sensoriels, ainsi que des défauts d’organisation des spermatides. De plus, chez les embryons, les protéines actrices du transport intra-flagellaire, NompB et CG11356, sont mal distribuées lorsque CBY est absente. Enfin, chez les mutants, la localisation de la protéine UNC est affectée dans les cellules germinales en fin de spermatogenèse. En conclusion, chez la drosophile, CBY est impliquée dans le tri protéique organisé à la base du cil de neurones sensoriels, de concert avec les autres protéines localisées à la zone de transition. Dans le testicule, CBY est nécessaire à la maturation des spermatides. En revanche, CBY n‟intervient pas dans la régulation de la voie wg
Cilia and flagella are organelles found from protozoa to mammals. Deregulation of the assembly (ciliogenesis) or function of cilia, causes various diseases in humans. Among those involved in ciliogenesis are the RFX transcription factors. The search for RFX target genes in Drosophila identified the Chibby (CBY) gene, previously described as an antagonist of the Wnt / wingless pathway. Unlike in vertebrates, in invertebrates is still no link established between cilia and the wg pathway. The identification of CBY as a target of dRFX in Drosophila suggests a ciliary function of CBY and would allow the establishment of the link cilia / wg pathway. CBY is localized at the transition zone of cilia of sensory neurons of the peripheral nervous system and at centrioles in spermatids. Drosophila invalidated for CBY present a phenotype of uncoordination, but no wg phenotype. These mutants have defects in sensory cilia and defects in organization of spermatids. In addition, in embryos, the distribution of proteins involved in intra-flagellar transport, NompB and CG11356, is affected when CBY is absent. Finally, in the mutants, the localization of the UNC protein is affected in germ cells at the end of spermatogenesis. In conclusion, in Drosophila, CBY is involved in the protein sorting organized at the base of cilia of sensory neurons, with the other proteins located at the transition zone. In the testes, CBY is necessary for the maturation of spermatids. However, CBY is not involved in the regulation of the wg pathway

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Marinelli, Andrea T. "Biologically Inspired Wing Tip Geometry Optimization." Digital WPI, 2010. https://digitalcommons.wpi.edu/etd-theses/805.

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Wingtip vortices are an important problem in aerodynamic and hydrodynamic engineering because of their contribution to induced drag, tip cavitation, and wake turbulence. These effects decrease equipment efficiency and lifespan, which increases application costs. Biology provides an inspiring solution to this problem in avian flight through the spreading of primary feathers. Previous studies have shown increased lift to drag ratio and efficiency of wings and propeller blades through modified wingtip geometry. The goal of this project is to optimize the tip geometry (primary feather angle) of a test wing for minimal tip vortex strength using genetic algorithms to mimic natural design evolution. Ultrasonic transducers are used to measure the wing tip vortex circulation in wind tunnel tests for each candidate design. Although neither angle of attack series converged completely, there was partial convergence in each. Due to the fluctuations in the low angle of attack tests, the parent selection algorithm was altered for the high angle of attack series, which resulted in improved convergence trends. A genetic algorithm that used uniform crossover breeding, a 20% mutation rate, and roulette wheel parent selection methods was used to generate an improved tip geometry at a low angle of attack of 6° and a freestream velocity of 15.25 m/s over the course of 17 generations. This improved design consisted of three key features, a staggered leading edge, a drastic mid-section vertical separation, and an upswept trailing edge. A second algorithm, which employed uniform crossover, a 20% mutation rate, and an elitist selection roulette parent selection, provided an improved tip geometry for a 12° angle of attack at a freestream velocity of 11.5 m/s. This improved design consisted of three key features, a downswept leading edge, a drastic mid-section vertical separation, and an upturned trailing edge. Both results showed that the wing tip vortex strength can be reduced by approximately 20% by manipulating tip geometry and that the trailing edge traits produce the most prominent effects on vortex strength.

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Dissertations / Theses on the topic 'Winglets'

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