89 research outputs found
Analysis of composite wing structures with a morphing leading edge
No full textOne of the main challenges for the civil aviation industry is the reduction of its environmental impact. Over the past years, improvements in performance efficiency have been achieved by simplifying the design of the structural components and using composite materials to reduce the overall weight. These approaches however, are not sufficient to meet the current demanding requirements set for a „greener‟ aircraft.
Significant changes in drag reduction and fuel consumption can be obtained by using new technologies, such as smart morphing structures. These concepts will in fact help flow laminarisation, which will increase the lift to drag ratio. Furthermore, the capability to adapt the wing shape will enable to optimise the aerodynamic performance not only for a single flight condition but during the entire mission. This will significantly improve the aircraft efficiency.
The current research work has been carried out as part of the European Commission founded Seventh Framework Program called „Smart High Lift Device for the Next Generation Wing‟ (SADE), which main aim is to develop and study morphing high lift devices. The author‟s investigation focused on developing a design concept for the actuation mechanism of a morphing leading edge device. A detailed structural analysis has been carried out in order to demonstrate its feasibility.In the first phase of the research the attention was directed on the preliminary design and analysis of the composite wing box. The parameters of the key structural components, such as skin, spars, ribs and stringers were set to satisfy the static stress and buckling requirements. Moreover, numerical and experimental studies were conducted to analyse the static failure and buckling behaviour of two typical composite wing structural components: a spar section and a web and base joint assembly.
In the second stage of the research, a design for the morphing leading edge actuation mechanism was developed. The actuation system was designed in such a way that the target shape was reached with minimum actuation force demand. A geometrical nonlinear FE analysis was conducted to simulate the leading edge morphing deflection and ensure that structural strength requirements were satisfied. Furthermore, the behaviour of the skin integrated with the internal actuation mechanism was modelled under the aerodynamic pressure, at different flight conditions and gust loads, in order to prove that the proposed actuation system can compete with the conventional rigid rib.
This study demonstrated that a feasible morphing leading edge design for a next generation large aircraft wing can be achieved. Developing the readiness of this technology will have a significant impact on aircraft efficiency and considerable contribution towards a more environmental friendly aviation
Ryoko Sekiguchi: l’exil entre simultanéité et surimpression
No full textIn an interview, Ryoko Sekiguchi remarked about her experience of exile: "exiled people always live two seasons simultaneously" (2021). This means, for example, that in winter she can live with the sky of Tokyo, Beirut or Granada, while being in Paris. This imaginative ubiquity of presence is not only at the center of her condition as a foreigner in France, but also at the heart of her poetic work, involving space-times characterized by a principle of simultaneity and by the constant attempt to superimpose several texts or several voices on the same sensitive surface. In this study, we analyze the role played by simultaneity and superimposition as poetic and heuristic tools in the poet's work. Among the works that make up his vast corpus, we have chosen to focus on Heliotropes. This book seems particularly significant to us, since it bases the simultaneity of all its constituent elements on the superposition between the poetic world and the world of plants. After briefly presenting the text, we explore the superposition between textual forms and plant forms in order to identify the principles of spatialization that allow Sekiguchi to neutralize time: we first look at the isomorphy between metric block and botanical block, because the measure chosen by the author is based on a principle of crystallization that leaves no room for random proliferation and reminds us, on the one hand, the geometric principles governing the formation of the regular and symmetrical structures of plants, and on the other, the desire for order that allows nature to be landscaped as a garden. Then, we examine the analogy between the forms of textual grafting and the so-called plant grafts. We thus wish to reconstruct the movements and space-times of this writing of exile which is configured as the simultaneous listening of multiple sounds.Lors d’un entretien, Ryoko Sekiguchi a remarqué à propos de son expérience de l’exil: «les personnes exilées vivent toujours deux saisons simultanément» (2021). Ce qui fait, par exemple qu’en hiver elle puisse vivre avec le ciel de Tokyo, de Beyrouth ou de Grenade, tout en étant à Paris. Cette ubiquité imaginative de la présence se pose non seulement au centre de sa condition d’étrangère en France, mais aussi au cœur de son œuvre poétique, impliquant des espace-temps caractérisés par un principe de simultanéité et par la tentative constante de superposer plusieurs textes ou plusieurs voix sur une même surface sensible. Dans le cadre de cette étude, nous analysons le rôle joué par la simultanéité et la surimpression en tant qu’outils poétiques et heuristiques dans l’œuvre de la poétesse. Parmi les ouvrages composant son vaste corpus, nous avons choisi de nous concentrer notamment sur Héliotropes. Ce livre nous semble particulièrement significatif, puisqu’il fonde la simultanéité de tous ses éléments constitutifs sur la superposition entre monde poétique et monde des plantes. Après avoir brièvement présenté le texte, nous explorons la superposition entre formes textuelles et formes végétales afin de dégager les principes de spatialisation qui permettent à Sekiguchi de neutraliser le temps : nous nous penchons d’abord sur l’isomorphie entre bloc métrique et bloc botanique, car la mesure choisi par l’auteure repose sur un principe de cristallisation qui ne laisse aucune place à la prolifération aléatoire et rappelle, d’un côté, les principes géométriques gouvernant la formation des structures régulières et symétriques des plantes, de l’autre, la volonté d’ordre qui permet d’aménager la nature en jardin. Ensuite, nous examinons l’analogie entre les formes de greffe textuelle et les greffes dites végétales Nous souhaitons ainsi reconstruire les mouvements et les espace-temps de cette écriture de l’exil qui se configure comme l’écoute simultanée des sonorités multiples
Analysis of composite wing structures with a morphing leading edge
No full textOne of the main challenges for the civil aviation industry is the reduction of its environmental impact. Over the past years, improvements in performance efficiency have been achieved by simplifying the design of the structural components and using composite materials to reduce the overall weight. These approaches however, are not sufficient to meet the current demanding requirements set for a „greener‟ aircraft. Significant changes in drag reduction and fuel consumption can be obtained by using new technologies, such as smart morphing structures. These concepts will in fact help flow laminarisation, which will increase the lift to drag ratio. Furthermore, the capability to adapt the wing shape will enable to optimise the aerodynamic performance not only for a single flight condition but during the entire mission. This will significantly improve the aircraft efficiency. The current research work has been carried out as part of the European Commission founded Seventh Framework Program called „Smart High Lift Device for the Next Generation Wing‟ (SADE), which main aim is to develop and study morphing high lift devices. The author‟s investigation focused on developing a design concept for the actuation mechanism of a morphing leading edge device. A detailed structural analysis has been carried out in order to demonstrate its feasibility.In the first phase of the research the attention was directed on the preliminary design and analysis of the composite wing box. The parameters of the key structural components, such as skin, spars, ribs and stringers were set to satisfy the static stress and buckling requirements. Moreover, numerical and experimental studies were conducted to analyse the static failure and buckling behaviour of two typical composite wing structural components: a spar section and a web and base joint assembly. In the second stage of the research, a design for the morphing leading edge actuation mechanism was developed. The actuation system was designed in such a way that the target shape was reached with minimum actuation force demand. A geometrical nonlinear FE analysis was conducted to simulate the leading edge morphing deflection and ensure that structural strength requirements were satisfied. Furthermore, the behaviour of the skin integrated with the internal actuation mechanism was modelled under the aerodynamic pressure, at different flight conditions and gust loads, in order to prove that the proposed actuation system can compete with the conventional rigid rib. This study demonstrated that a feasible morphing leading edge design for a next generation large aircraft wing can be achieved. Developing the readiness of this technology will have a significant impact on aircraft efficiency and considerable contribution towards a more environmental friendly aviation.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Do anabolic steroids impact cognition? An evaluation of Androstenedione's impact on spatial cognitive performance in the young male rodent
No full textabstract: Following natural menopause, androstenedione becomes the main hormone secreted by the follicle-depleted ovaries. We have previously evaluated high physiological doses of androstenedione in the female rodent, and found relations between higher androstenedione levels and spatial memory impairment; this relationship was shown when androstenedione levels were of endogenous, or exogenous, origin (Acosta et al., 2009, Camp et al., 2012). This androstenedione-induced memory impairment in females led us to question whether this androgen also impairs memory in males; no study has yet evaluated androstenedione's impact on cognition in the male rodent model. This is a clinically relevant question, as androstenedione is a steroid of abuse. In the current study, four-month old male rats were given either a daily injection of androstenedione, androstenedione with anastrozole or vehicle (polyethylene glycol). Subjects completed a battery of cognitive tasks evaluating spatial working, reference, and recent memory including the water radial arm maze (WRAM), Morris water maze (MM), and delayed match-to-sample maze (DMTS). We found that androstenedione administration impaired spatial cognitive performance in MM on early overnight forgetting and DMTS early recent memory trials across all days of testing. In addition, we found that androstenedione with anastrozole administration impaired spatial cognitive performance in the learning phases and early overnight forgetting in the MM but had no impact in DMTS testing. There were no significant differences in the WRAM maze for either group. Our findings suggest that androstenedione can impair spatial reference and early recent memory, and that anastrozole reverses this impairment for early recent memory, but not reference memory. Interpreted in the context of hormone conversion, androstenedione's effects on spatial learning and memory may be due, in part, to its conversion to estrone
Exploring Emptiness: An Investigation of MA and MU in My Sonic Composition Practice
No full textThe commentary investigates Japanese aesthetics of space, silence and emptiness - ma and mu - that informed my compositional practice during the research period 2012 - 2015. The portfolio comprises text compositions and sound installations in which forms of micro events and sustained events are employed. Throughout, the emphasis is on my personal engagement with, and manifestation of emptiness that concerns a particular model of listening and perception.
Chapter 1 discusses six primary research areas: ma and mu, material, text, form, listening and perception. Firstly, I introduce ma and mu by examining noh culture and Zeami's teaching of senu hima (where there is no-action) in the context of my personal approaches to music. The following subjects are then used to contextualise my PhD practice by means of examples from various composers and visual artists. Here, these particular and enigmatic concepts are explored through Japanese art as well as Western contemporary works by Alvin Lucier, Eliane Radigue and those of the Wandelweiser collective.
Part 2 provides contextual commentaries on selected compositions from the portfolio that mostly articulate my aesthetics in relation to the topics covered in Chapter 1. koso koso addresses my methodologies to investigate the essence of senu hima, followed by treow that discusses my approach to materials and the importance of space. I move on to grade two and grade two extended in order to examine text scores, and then, look into Espèces d'espaces 03 and 04 as examples of musical forms that I employ.
Finally, listening and perception are investigated through the compositions gnome and con.de.structuring. Throughout, I describe how my works explore emptiness as a result of my particular emphasis on listening over composing
Helmee Imaging Oy : How to make negotiation smooth between Japanese and foreign companies
No full textThis thesis’s commissionaire was Helmee Imaging Oy. The company develops software for glossy surface inspection. They are also manufacturing inspection devices with their software and selling them. They want to expand their business to Japan, however they do not have experiences working with Japanese companies.
The author has studied about intercultural communication’s various kinds of aspects and Japanese culture from online sources and books. In addition to it, the author has conducted qualitative interview research to find current existing cultural barriers between Japanese and foreign companies. Two groups of people were interviewed. One was Japanese people who have experienced business to business negotiation with foreign companies. The other group was composed of non-Japanese people who have experiences dealing with Japanese companies.
From research based on existing theories, the author found various kinds of cultural aspects containing possibility to be obstacles for smooth negotiations. The questions for the interviews are structured based on those potential barrier factors. As a result, the author was able to determine those which affect communication.
Communication strategy plan for the Helmee Imaging Oy is based on the interview research. First step is to look for Japanese companies who connect the commissionaire and potential Japanese customers. Having connections is vital in Japan as it gives trust easily. Another way of getting trust efficiently is meeting with Japanese people in person. In addition to it, understanding Japanese culture and adaptation will give positive impression to them. To minimize the miscommunication, English should be adjusted to their level and maintaining long term relationships with same people should be encouraged. This will eventually make them feel more at ease and communication smoother. The results of the study will be useful for the commissionaire in the future when deciding the path to enter Japanese market
Slow postseismic recovery of geoid depression formed by the 2004 Sumatra-Andaman Earthquake by mantle water diffusion
No full textEarthquakes are accompanied with mass redistributions and cause changes in gravity field and shape of geoid, an equipotential surface coincident with the mean sea surface. Such coseismic changes were detected by satellite gravimetry after the 2004 Sumatra-Andaman Earthquake [Han et al., 2006], but little has been known on what happens on geoid after the earthquake. Here we report slow postseismic recovery of coseismic geoid depression from satellite measurements. This cannot be explained with simple afterslip or viscous relaxation of Maxwellian upper mantle. It suggests the relaxation of coseismic dilatation and compression by the diffusion of supercritical H2O abundant in the upper mantle. Such a self-healing system of coseismic geoid undulations, a brand-new role of water in mantle, would significantly reduce the amount of permanent shifts of the Earth’s rotation axis by earthquakes
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