This aircraft industry is concerned with the increase of drag on planes due to the sticking of insects on critical airfoil areas. The objectives of the present study were to investigate the effects of surface energy and elasticity on the number of insects sticking onto the polymer coatings on a modified aircraft wing and to determine the mechanism by which insects stick onto surfaces during a high-Velocity impact. Analyses including scanning electron microscopy (SEM), electron spectroscopy for chemical analysis (ESCA) and contact angle measurements of uncoated and polymer-coated aluminum surfaces have been performed. An air-gun was designed to accelerate insects to high speeds and impact them onto modified wing surfaces in a laboratory environment. A direct relation between the number of insects sticking on a sample and its surface energy was obtained. Since the sticky liquid from a burst-open insect will not spread on the low energy surface, it will ball up providing poor adhesion between the insect debris and the surface. The incoming air How can easily blow oH' the insect debris thus reducing the number of insects that remain stuck on the surface. Also a direct relation between the number of insect sticking onto sample surfaces and their moduli of elasticity was obtained. The deceleration of an insect impacting onto an elastomer reduces in proportional to the modulus of elasticity of the material. As a consequence, the rate of change of momentum is lower and the force and pressure exerted on the body of the insect is reduced if it impacts onto a material with a low modulus of elasticity. This lessens the chance of bursting the i insect exoskeleton. / Master of Science

Using a general, unsteady, nonlinear vortex lattice method, the aerodynamic loads have been found on a 75° delta wing with and without leading edge vortex flaps. The flap had an area approximately 26 percent of the wing area with a constant chord of 6.7 percent of the wing mean aerodynamic chord and was deflected at 30°. Results for lift, drag, axial force, and pitching moment coefficients are compared with experimental data and show very good agreement. Individual pressure difference coefficients along the wing and flap are also presented and compared with experimental data. Overall, the method shows the leading edge vortex flap to be very effective in reducing drag while maintaining lift comparable to that of the plain wing. / Master of Science

Engineering design is hierarchical in nature, and if no attempt is made to benefit from this hierarchical nature, design optimization can be very expensive. There are two alternatives to taking advantage of the hierarchical nature of structural design problems. Multi-level optimization techniques incorporate the hierarchy at the formulation stage, and result in the coordinated optimization of a hierarchy of subsystems. The use of multi-level optimization techniques often necessitates the use of equality constraints. These constraints can sometimes cause numerical difficulties during optimization. Single-level decomposition techniques take advantage of the hierarchical nature to reduce the optimization cost. In this research the decomposition approach has been followed to reduce the computational effort in a single-level design space. A decoupling technique has been developed that retains the advantages of a partitioned system of smaller independent subsystems without an increase in the total number of design variables. A penalty function formulation using Newton's method for the solution of a sequence of unconstrained minimizations was employed. The optimization of the decoupled system is cheaper due to (i) cheaper evaluation of the hessian matrix by taking advantage of its sparsity, (ii) fewer global analyses for constraint derivative calculations, and (iii) utilizing the decoupled nature of the hessian matrix in the solution process. Further, the memory requirements of the decoupled system are much less than that of the original coupled system. These benefits increase substantially for design problems with larger and larger number of detailed design variables. Orthotropic material properties as stiffness global variables have been shown to be effective as global variables for panels in a hierarchical wing design formulation. The proposed decoupling technique was implemented to minimize the volume of a portal frame and a wing box. Computational savings of up to 50 percent have been obtained for medium sized problems. The savings increase as the size of the problem and the amount of decoupling is increased. The procedure is simple to implement. For truly large systems this decoupling technique provides the necessary reduction of computational effort to make the optimization process viable. / Ph. D.

The objective of this research is to verify the three degree of freedom capabilities of a bio-inspired quad flapping-wing micro aerial vehicle in simulation and in hardware. The simulation employs a nonlinear plant model and input-output feedback linearization controller to verify the three degree of freedom capabilities of the vehicle. The hardware is a carbon fiber test bench with four flapping wings and an embedded avionics system which is controlled via a PD linear controller. Verification of the three degree of freedom capabilities of the quad flapping-wing concept is achieved by analyzing the response of both the simulation and test bench to pitch, roll, and yaw attitude commands.

Aerodynamic analysis is an important area of survivability studies. There is a desire to be able to predict the aerodynamic effects of a given damage scenario on an aircraft wing with minimal wind tunnel testing or computational simulations. Due to the limited nature of previous studies, this has not generally been possible. The original contribution of this thesis is a predictive technique developed to estimate the aerodynamic effects of a simulated battle damage hole on an aircraft wing, resulting from a range of attack directions. This technique was successfully validated against experimental data. Testing under two-dimensional conditions was undertaken on a NASA LS(1)-0417MOD aerofoil at a Reynolds number of 500,000. This project simulates the effect of attack direction by varying the offset between upper and lower surface damage holes in both chordwise and spanwise directions. Damage was modelled using circular holes. Lift, drag and pitching moment coefficients were measured and supplemented with surface flow visualisation and surface pressure measurements. Coefficient increments, defined as the difference between the damage cases and a datum undamaged case were used to quantify the effects of the damage, with the performance qualified in terms of weak and strong jets. Weak jets were found to have little effect on the flow and aerodynamic properties, while strong jets caused significant disruption. The effects increased in magnitude with hole size, incidence and proximity of the upper surface hole to the pressure peak. Spanwise offset on the holes had little effect on the jet strength but introduced asymmetry into the surface flow. This effect was found to be due to the behaviour of the flow within the cavity. Three-dimensional testing was undertaken at a Reynolds number of 1,000,000 on a half wing model in order to investigate any changes in the aerodynamic characteristics of the damage when applied to a more representative aircraft wing. The higher Reynolds number exploited the larger wind tunnel working section and provided a value more representative of typical unmanned aerial vehicles. As the damage was moved towards the tip its effects were lessened and the transition from weak jet to strong jet delayed. Spanwise pressure variation from the tip also introduced asymmetry into the jet s surface flow features. Plotting coefficient increments for all attack directions against the pressure coefficient difference between upper and lower surfaces from an undamaged wing, across the equivalent damage hole region highlighted significant trends, which were used as the basis of a predictive technique for a range of hole sizes and attack directions. The validity of the technique was assessed by predicting a previously untested damage case and comparing it against subsequent wind tunnel tests. The results from this validation proved encouraging.

Aeroelastic behavior prediction is often confined to analytical or highly computational methods, so I developed a low degree of freedom computational method using structural finite elements and unsteady loading to cover a gap in the literature. Finite elements are readily suitable for determination of the free vibration characteristics of eccentric, elastic structures, and the free vibration characteristics fundamentally determine the aeroelastic behavior. I used Theodorsen’s unsteady strip loading formulation to model the aerodynamic loading on linear elastic structures assuming harmonic motion. I applied Hassig’s ‘p-k’ method to predict the flutter boundary of nonsymmetric, aeroelastic systems. I investigated the application of a quintic interpolation assumed displacement shape to accurately predict higher order characteristic effects compared to linear analytical results. I show that quintic interpolation is especially accurate over cubic interpolation when multi-modal interactions are considered in low degree of freedom flutter behavior for high aspect ratio HALE aircraft wings.

在亨利‧詹姆士（Henry James）的小說《鴿之翼》（The Wings of the Dove, 1902）中，金錢在人際關係中的流動以及其所產生的交換方式往往為批評家們所忽略。許多批評家將小說中的角色視為兩種極端：以凱特為代表的倫敦人是剝削者；美國女孩米莉則是天真無邪的犧牲者。而注意到小說中交換議題的批評家，也多半以市場交易的模式來看待小說中的交換行為。有別於以往的研究，本論文嘗試以「禮物」的理論，為小說中的交換提供一種新的觀點。 / 法國人類學家牟斯（Marcel Mauss）的理論顯示，禮物贈與牽涉到社會關係的建立與經濟層面的交流。然而牟斯的理論亦顯示出禮物的矛盾：禮物並非單向的贈與，而是送／收禮物的主體之間的互惠交換行為。同樣的，《鴿之翼》中的金錢交換也是以此種送／收禮物的方式來達成。小說中的禮物交換與角色對金錢的追求呼應，形成一個禮物交換的體系。本論文首先討論小說中的交換者進行交換的方式，突顯其用以掩飾禮物矛盾的包裝策略。其次，本論文討論禮物交換的時間結構如何對送禮者與收禮者產生不同的影響，使米莉的回禮得以藉由時間的運用，產生諧擬（parody）的效果，進而展示了凱特所代表的倫敦人所遵從的交換原則有何限制。 / 在《鴿之翼》中，禮物不斷游移於慷慨與私利的兩端，而此種介於經濟與非經濟之間的交換方式，正是禮物有別於商品，並能夠暗渡實質利益的原因。 / In The Wings of the Dove (1902), Henry James presents a flow of money in interpersonal relations from which a distinctive mode of exchange is derived. However, the issue of exchange does not arouse much discussion among the critics on James. Some critics tend to read the two heroines as representatives of moral oppositions—Kate and other Londoners as exploiters, the young American Milly as a victim. Although there are other critics who notice the exchanges in this novel, most of them choose to approach the issue with the mode of exchange in the market. Differing from these critical perspectives, in which the characters’ exchanges are taken as transforming or reflecting transactions of commodities, this thesis analyzes The Wings of the Dove in terms of gift giving and gift returning. / As the work of the French anthropologist Marcel Mauss shows, gift giving is not only a way to construct social relations but also a part of an economic circulation. But a paradox of the gift can also be observed from Mauss’s theory of the gift—the paradox that gift giving appears as a liberal offer but initiates an exchange of gifts by obligating the gift receiver to return. / What this thesis aims to explore with the theories of the gift is whether it is effective for the characters in The Wings of the Dove to exchange money for social resources, and vice versa. The exchanges in this novel, working alongside the Londoners’ quest for money, constitute a system of gift exchange that brings about Kate’s scheme to reap money from Milly. To look into the problems created from this mode of exchange, the thesis will further be committed to the discussions on the characters’ strategies which help them conceal the paradox of the gift, as well as their actions and limitations in the temporal structure of the gift exchange. Ultimately, this thesis attempts to show the capriciousness of the gift revealed in the exchanges in The Wings of the Dove. In constant fluctuations, the gift never ceases to oscillate between the dichotomies of the economic and the noneconomic, which not only shows its elasticity but also offers a space for discussions of its logic from various critical angles.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-07-30T15:07:27Z No. of bitstreams: 1 OLYMPIO CIPRIANO DA SILVA FILHO - DISSERTAÇÃO PPGEE 2007..pdf: 1354330 bytes, checksum: 4271b1c8fe8556d562518fb586e85376 (MD5) / Made available in DSpace on 2018-07-30T15:07:27Z (GMT). No. of bitstreams: 1 OLYMPIO CIPRIANO DA SILVA FILHO - DISSERTAÇÃO PPGEE 2007..pdf: 1354330 bytes, checksum: 4271b1c8fe8556d562518fb586e85376 (MD5) Previous issue date: 2007-12-14 / Com o desenvolvimento tecnológico a computação está cada vez mais integrada ao cotidiano das pessoas. Esta integração faz parte de um novo paradigma da computação: o da Computação Pervasiva. Neste paradigma, a computação está sempre a disposição do usuário, em qualquer lugar, a qualquer momento, através de ambientes repletos de dispositivos computacionais embutidos em uma grande variedade de objetos do dia-a-dia das pessoas como, automóveis, telefones, etc. Nestes ambientes, os dispositivos interagem entre si através de serviços devendo ser capazes lidar com a grande variedade de protocolos de descoberta de serviços disponíveis. Ainda,essas interações entre os dispositivos podem ocorrer em ambientes sem infra-estrutura de redes de computadores e entre dispositivos que podem agir desonestamente. Neste trabalho, é desenvolvido um modelo para avaliar a confiança nos serviços nos ambientes pervasivos a partir de experiências e recomendações. Este modelo é implementado por um Gerenciador de Informação de Confiança o qual disponibiliza um mecanismo de tomada de decisão para realizar a seleção de clientes e provedores de serviço. Ainda, o Gerenciador de Informação de Confiança é integrado a um middleware para computação pervasiva, o Wings, possibilitando a descoberta de serviços confiáveis. Foram utilizadas simulações e uma aplicação de teste para avaliar o Gerenciador de Informação de Confiança e sua integração ao middleware Wings. A partir dos resultados obtidos observou-se que a solução apresentada se mostrou satisfatória para a utilização em ambientes pervasivos. / The development of technology is integrating computing to people every day life. This integration belongs to a new computing paradigm: the pervasive computing. In this paradigm, the computation is always available, in every place at any time, through environments crowd of computing devices embedded in a great variety of objects like cars,cell phones, etc. In these environments, devices interact through services and should be able to deal with different service announcement solutions available. These interactions can occur without computing network infrastructure andamong malicious devices. In this work, it is developed a model to evaluate service trust in pervasive environments from experiences and recommendations. This model is implemented by a Trust Information Manager that provides a mechanism to make trust based decision. This Trust Information Manager is integrated to a pervasive computing middle ware,called Wings, enabling trusted service discover. Simulations and a test application were used to evaluate theTrust Information Manager and its integration with the Wings middleware. From the results it could be seen that the presented solution is efficient and can be widely used in pervasive computing environments.

abstract: Broadband dielectric spectroscopy is a powerful technique for understanding the dynamics in supercooled liquids. It generates information about the timescale of the orientational motions of molecular dipoles within the liquid. However, dynamics of liquids measured in the non-linear response regime has recently become an area of significant interest, because additional information can be obtained compared with linear response measurements. The first part of this thesis describes nonlinear dielectric relaxation experiments performed on various molecular glass forming-liquids, with an emphasis on the response at high frequencies (excess wing). A significant nonlinear dielectric effect (NDE) was found to persist in these modes, and the magnitude of this NDE traces the temperature dependence of the activation energy. A time resolved measurement technique monitoring the dielectric loss revealed that for the steady state NDE to develop it would take a very large number of high amplitude alternating current (ac) field cycles. High frequency modes were found to be ‘slaved’ to the average structural relaxation time, contrary to the standard picture of heterogeneity. Nonlinear measurements were also performed on the Johari-Goldstein β-relaxation process. High ac fields were found to modify the amplitudes of these secondary modes. The nonlinear features of this secondary process are reminiscent of those found for the excess wing regime, suggesting that these two contributions to dynamics have common origins. The second part of this thesis describes the nonlinear effects observed from the application of high direct current (dc) bias fields superposed with a small amplitude sinusoidal ac field. For several molecular glass formers, the application of a dc field was found to slow down the system via reduction in configurational entropy (Adam-Gibbs relation). Time resolved measurements indicated that the rise of the non-linear effect is slower than its decay, as observed in the electro-optical Kerr effect. A model was discussed which quantitatively captures the observed magnitudes and time dependencies of the NDE. Asymmetry in these rise and decay times was demonstrated as a consequence of the quadratic field dependence of the entropy change. It was demonstrated that the high bias field modifies the polarization response to the field, even including the zero field limit. / Dissertation/Thesis / Doctoral Dissertation Chemistry 2016

Magister Artium - MA / The political participation of women in parliaments is not only important for sustainable development of every country, but it is also crucial for their voices to be heard, as they form at least half of the world’s population. Furthermore, women’s presence in significant decision-making positions represents an indicator of gender transformation and mainstreaming. However, women remain largely underrepresented in parliament and state institutions in Ghana with a current representation of 8.3% in parliament.Against this background, this study evaluates the role of women wings in enhancing women’s representation in parliament, by exploring the gendered social, political and ideological contexts in which they operate and assesses the constraints and challenges to their effective involvement in parliament. Using in-depth interviews and focus group discussions, the research analyses the activities of three main political parties’ women’s wings in the Greater Accra Region of Ghana by addressing the following key questions: (i) What are the demographic features of members of the women’s wings in Ghana? (ii) What structures and relationships influence women’s participation and advancement in Ghanaian politics? (iii) Do women’s wings attached to political parties have the capacity to advance the agendas of women and gender equality in Ghana or are they constrained by loyalties to male-dominated parties? (iv) To what extent do women’s wings address gendered political structures and ideology within Ghanaian society generally, and Ghanaian politics specifically? (v) Do women’s wings of different parties perform different roles, and reflect different strategies for enhancing women’s public participation? The findings indicated that women’s wings affiliated to political parties are constrained by their loyalty to their political parties resulting in a lack of a clear feminist consciousness.There was also lack of cooperation among the women’s wings which also affected their ability to enhance gender equality in the country. In addition cultural norms and discriminatory practices together with a lack of financial resources were found to be major obstacles to the effectiveness of the women’s wings in Ghana in achieving gender equality and social justice. The study therefore recommends a need for a stronger feminist consciousness and the building of women’s solidarity among and between women’s wings to enable them to address the strategic gender needs of the country and achieve gender equality in Ghana.