Dissertations / Theses on the topic 'Autogiro'

Mestrado em Engenharia Mecânica
O trabalho apresentado teve como principal objetivo a caracterização dos problemas aerodinâmicos e estruturais a serem observados no projeto de um Autogiro. Numa primeira etapa do trabalho, alguns conceitos básicos dos princípios da aerodinâmica que gera forças durante o voo destas aeronaves são delineadas. Numa segunda parte os componentes integrantes de um autogiro são modelados, onde alguns serão examinados por elementos finitos. Seguidamente foi realizado um cálculo á sustentação da asa, de modo a que o autogiro consiga levantar voo. Posteriormente, realizaram-se cálculos em algumas ligações aparafusadas, que se consideraram ser mais importantes para a intensidade das forças. Este cálculo teve como o objetivo, determinar se as ligações aparafusadas respeitam o critério de segurança. Finalmente, executou-se uma análise em elementos finitos na estrutura e no rotor, de maneira a avaliar o comportamento em termos da distribuição de tensões. Nesta etapa final também foi realizada uma análise às vibrações do autogiro, determinando as frequências naturais na estrutura e asa do rotor.
The work presented had as main goal the characterization of the problems of the aerodynamics and structural parameterization to be observed in the design of Autogyrus or Gyroplanes flight vehicles. In a first step, some basic concepts of the principles of aerodynamics that generates forces during the flight of these machines are outlined. In a second step, the integrating parts of the autogyrus are modeled, where some will be examined by finite element analysis. Then a calculation on the wing lift was performed, so that the autogiro can take the flight. After, calculations were performed in some bolted connections, considered to be most important for the forces intensity. This calculation had as objective to determine whether the bolted connections accomplished safety criteria. Finally, it was performed a finite element analysis in the structure and rotor, in order to evaluate the performance in terms of stress distribution. In this final stage it was also conducted an analysis of vibrations, determining the natural frequencies in the structure and rotor wing during its rotation.

Airborne remote sensing is so far one of the most important application in the general field of remote sensing. Since from the first aircrafts, different film cameras were used to acquire images lately treated by a photogrammetric approach. The airborne remote sensing potentials are generally opposed to the high cost normally associated to this activity and to the need of high specialized operators for fieldwork and laboratory processing. In the last years, several factors have allowed an increase in the number of users of airborne remote sensing data; among these, it is important to mention the development of processing techniques based on Computer Vision (CV) and the Structure from Motion (SfM) algorithms, the increase of simplicity and power of the remote sensing software, the exponential growth of computing power, and the relative low price of modern workstations. Main goals of this PhD research project are: 1) the development and optimization of a manned prototypal aircraft agile, economical and functional for multi-parametric scientific survey; 2) the acquisition, processing, presentation and accuracy validation of different datasets acquired thanks to the developed aircraft. The device is, technically, an autogyro called “RadGyro” for its initial use in natural radioactivity survey. The autogyro is extremely agile, quite inexpensive, and with a high load capacity (actual maximum payload reaches about 100 kg). In the first phase, during the construction and optimization of the RadGyro, the scientific instrumentation, used in the second phase of the project, was implemented. The second phase was carried out by testing potentials and limits of the system through the experience derived from the most significant case studies. The focus was on the photogrammetric sub-system, but lateral activity has concerned the use of a thermo-camera and of a hyperspectral visible/near infrared pushbroom scanner. The photogrammetric sub-system was assessed trough different case studies in order to check the quality of the processed products; by the creation of Digital Elevation Models (DEM), Digital Terrain Models (DTM) and ortophotos, it was possible to update the existing maps also minimizing the operator interpretation of landforms thanks to a high resolute and spatially continuous acquisition. The RadGyro and the SfM techniques allowed reducing to few days fieldwork activities necessary for traditional topographic survey by GNSS (Global Navigation Satellite System) and Total Station. It is impossible, for the traditional topographic survey to reach a 3D point clouds density as high as the one reachable by the application of image matching techniques, except using terrestrial or airborne LIDAR (Light Detection and Ranging). However, to obtain high positional accuracy, the survey with geodetic instrument of well distributed GCPs (Ground Control Points) still remains indispensable. The class of the Inertial Measurement Unit (IMU) and GPS (Global Positioning System) receivers affects the quality of the acquired data: this accuracy can be considered sufficient in navigation, surveying and pre-processing phases, but when centimetric accuracy is requested (quite typical for an photogrammetric flight), at least a post-processing correction or a field topographic acquisition of GCPs are needed. Aerial photogrammetry by means of RadGyro and SfM gave worthy results also in multi-temporal monitoring, with the big plus that the survey of many sites of interest has been possible only by a single low-altitude flight. The actual configuration of the RadGyro can be used, with good results, in areas where surface ranges between some square kilometres to many dozens of square kilometres. This is especially true when the costs and acquisition times required of a UAV (Unmanned Aerial Vehicle) flight are too high or when the accessibility of the site is complicated for traditional terrestrial surveys. Beside the validation of the photogrammetric sub-system, also sensors operating in the thermal and visible-near infrared range are now operative in the RadGyro thanks to parallel activities that allowed to develop ad hoc software, to make test flights and to complete the implementation of a workflow relative to data processing. At the end of the PhD research project, all these sensors are integrated and operational on board.

Thesis (Ph.D)--Aerospace Engineering, Georgia Institute of Technology, 2009.
Committee Chair: J.V.R. Prasad; Committee Member: Daniel P. Schrage; Committee Member: David A. Peters; Committee Member: Dewey H. Hodges; Committee Member: Lakshmi N Sankar. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Aviation is a pastime enjoyed by many amateur pilots. Of the 21 000 aircraft registered in the UK [1], 96% are engaged in general aviation activities (non-commercial flying). The UK Civil Aviation Authority (UK CAA) classifies microlights, gliders and autogyros as recreational sports aircraft. Of the 21 000 UK-registered general aviation aircraft, only 306 are autogyros, compared to over 4300 microlights and almost 2600 gliders. Despite this fact, the autogyro has been seen to exhibit a fatal accident rate up to 100 times higher than those of the microlight or glider. In response to the identification of this high accident rate amongst autogyro type vehicles, the CAA commissioned a programme of research intended to understand the cause. This research, undertaken in the UK by the University of Glasgow, consisted of analytical, wind tunnel and flight test activities. These studies concluded that the autogyro displayed “conventional lateral and directional dynamic stability characteristics”, and that both the static and dynamic stability (in particular, a lightly damped phugoid mode) was highly sensitive to the vertical position of the centre of gravity (c.g.) relative to the propeller thrust line. The lack of provision within the autogyro community to collect meaningful data in relation to the airworthiness requirements was also highlighted. Outside of the work performed as part of the research programme that generated this report, there is still considered to be “little indication that rigorous scientific or engineering investigation of airworthiness has occurred”. Therefore, there remains significant scope for further research into just what makes autogyros so unsafe to fly and how to improve their airworthiness. Prior research into the autogyro and its aerodynamic characteristics can be broadly divided into two phases, the first being from its inception in 1923 to the beginning of World War II and the period between 1996 and the present day, when a resurgence of interest in the autogyro began to occur. Much of the early works concentrate on characterising the autogyro’s aerodynamic characteristics, relying heavily upon wind tunnel testing, flight testing and analytical investigation to establish an understanding of the fundamental flight dynamics of the autogyro. With the first flight of the first functional helicopter, the outbreak of World War II and the death of the inventor of the autogyro, research interest in this aircraft type was critically diminished. Only three papers on the subject of autogyros were published between 1939 and 1996. The Air Accident Investigation Branch (AAIB) review of the airworthiness of the grounded Air Command autogyro, conducted after the occurrence of 5 fatal accidents between 1989 and 1991, recommended the commissioning of a programme of research into both the airworthiness and aerodynamic characteristics of light autogyros. As a result of this recommendation, the autogyro experienced a resurgence in research interest, culminating in the publication of a CAA Paper which presented 4 recommendations intended to improve the airworthiness of the autogyro: 1. It is recommended that the vertical location of the centre of gravity (c.g.) should lie within a ± 2 inch envelope of the propeller thrust line. 2. Horizontal tailplanes are largely ineffective in improving the long term pitch dynamic stability (phugoid mode). 3. Extreme manoeuvring can lead to excessive rotor teeter angles during certain phases of flight, potentially resulting in the rotor blades striking the prop or empennage. 4. The chordwise centre of gravity of the rotor blades should always lie at or ahead of the 25% chord position to prevent rotor blade instability. One of the primary aims of this Thesis was to assess the validity and applicability of these recommendations; in order to do so, a simulation model of an autogyro was created. The model was based on the G-UNIV research autogyro owned by Glasgow University and validated against flight test data in order to ensure the required level of fidelity was achieved. Upon re-assessing the recommendations, in some cases, different conclusions were drawn. The first recommendation, while accepted as a sensible design aim, was found to be overly restrictive. BCAR Section T, the airworthiness specification for autogyros, specifies requirements on the period and time to half amplitude of any longitudinal oscillations present in the aircraft. Limiting the vertical position of the centre of gravity to within ±2 inches of the propeller thrustline resulted in forcing a design which is compliant with the requirements of BCAR Section T outside the specified range, to become non-compliant when the centre of gravity lies within the range. Recommendation 2 suggests that the removal of the tailplane of the aircraft has little impact on the longitudinal trim control positions and the characteristics of the phugoid mode. It was found that the results from the simulation model disagreed with this conclusion; the removal of the tailplane changed the characteristics of the phugoid model and the trimmed control positions significantly. The third recommendation highlighted the potential for a rotor blade to strike the propeller or the empennage under extreme manoeuvring. The simulation environment provided a safe environment in which to test this recommendation; it was found under the loading of an extreme manoeuvre it was possible for the main rotor to strike the tail, supporting the conclusion drawn in CAA Report 2009/02. It was not possible to assess the fourth and final recommendation, relating the positioning of the chord-wise position of the blade centre of gravity, due to the limitations of the simulation model developed. Another focus of the recent work surrounding the autogyro has been on quantifying and assessing the handling qualities of such vehicles. This presents many challenges, including the fact that no autogyro-specific handling qualities specifications currently exist. One of the main themes of this Thesis was to progress towards the creation of such a specification, either through development of a new methodology or development of existing specifications, such as ADS-33E-PRF. The first steps in this field have been taken by Glasgow University using ADS-33; the primary specification used in the assessment of military rotorcraft. Assessment of the autogyro was previously carried out in a real-world flight trial using existing Mission Task Elements (MTEs) taken from ADS-33, the Slalom and the Acceleration-Deceleration. The results from this trial were then used to derive proposed Level 1, 2 and 3 boundaries for quickness and pilot attack. This Thesis replicated this trial using real-time piloted simulation, and the method described in the work carried out by Glasgow University was also utilised to derive a set of predicted handling qualities Levels for both quickness and pilot attack. It was found that the predicted Level boundaries generated from the simulation trial did not agree well with those predicted in the original flight trial. There were several reasons for this; in the original flight trial the pilot used a non-standard technique to fly the Slalom manoeuvre, using sideslip to complete the test course. Additionally, both the original flight trial and the simulated flight trial used data from several different course geometries. This resulted in the ordering of the Level boundaries being reversed for the Levels predicted by the simulated flight trial, as those test points carried out on the more aggressive course geometries received lower handling qualities ratings, whilst using the most aggressive control inputs, compared to those on easier courses which used lower magnitude and aggression inputs, and thus a lower quickness, while receiving better handling qualities. Recommendations were made to address these issues in future iterations of this work.

An autogyro or Autogiro is a unique type of rotary-wing aircraft that was successfully flown in the 1920s, many years before the first helicopter came to service. As far as the rotorcraft technology is concerned, the technical issues addressed by autogyros were eventually rectified and paved the way for the success of helicopter development. When helicopter became more popular and accepted in the civil aviation industry in the 1940s, autogyros were nearly forgotten and the popularity slowly diminished. The re-emergence of autogyros in the last two decades in hobby and sports flight activities, however, coincides with bad safety records due to stability issues. At the time of this writing, there are no specific flying qualities standards to be em- ployed as guidelines to design a light autogyro with good stability attributes. The only requirements available are addressed in the BCAR Section T airworthiness standard for light autogyros which only prescribes some basic dynamic stability requirements for the vehicle. For existing conventional light autogyros which mostly of 'home-built' type, complying with the airworthiness standards would be an issue as most of them were built beforehand. From these concerns, this Thesis aims to improve the flying qualities performance of existing light autogyros through automatic flight control methods, as one of the ways to practically achieve the required performance. Consequently, specific flying qualities requirements for light autogyros must first be proposed as preliminary guidelines for design and flying qualities improvement. A generic mathematical model of light autogyros named ARDiS is developed based on the 'multiblade' simulation ap- proach which is computationally cost-effective. This model was successfully validated against real autogyro flight data and later implemented in the control enhancement of the vehicle. The control enhancement was developed using classical approaches with limitation in size and simplicity of the vehicle as a light aircraft. Proper actuation control hard- ware was separately modelled and deployed into the autogyro to demonstrate a higher dynamics in the control mechanism so that a more realistic attitude behaviour of the vehicle is presented. This control enhancement was successfully evaluated with both, linear and nonlinear simulations according to the proposed autogyro flying qualities attributes. All presented results signify a higher possibility of improving the flying qualities of currently used and future built light autogyros through control enhance- ment.

Thesis (Ph. D.)--Aerospace Engineering, Georgia Institute of Technology, 2008.
Committee Chair: Dimitri N. Mavris; Committee Co-Chair: Daniel P Schrage; Committee Member: David A. Peters; Committee Member: Dewey H. Hodges; Committee Member: J.V.R. Prasad.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2005.
Includes bibliographical references (p. 93-94).
Precision airdrop is a technology whose required capabilities have become more exacting as combat situations necessitate greater degrees of accuracy. Ballistic and parafoil type delivery vehicles do not have the capacity to consistently deliver a payload on, for example, a particular rooftop in an urban combat situation. A gliding autogyro delivery platform has been investigated as a means of achieving greater airdrop performance. The autogyro has similar gliding characteristics to the parafoil, but has improved wind resilience and control authority. An initial simulation, based on momentum and blade element helicopter theory, has been constructed. A classical controller using a multiple loop closure strategy has been developed that uses a new nonlinear guidance law to follow paths generated by an algorithm considering initial conditions. An extended Kalman filter is used for state estimation. Results from simulations show consistent accuracy of about 5 feet, with the final position error rarely exceeding 10 feet.
by Joshua F. Torgerson.
S.M.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2005.
"CSDL-T-1503, digital appendix"--CDROM label. Appendix B of thesis text contains an index to the CDROM.
Includes bibliographical references (p. 113-114).
Currently, Draper Laboratory is in the development stages of a gliding autogyro airdrop system. The goal of the project is to design a platform capable of placing small, high value items into urban terrain. Theoretically, autogyros can achieve descent rates and glide slopes similar to current parafoil based systems, but do so with greater precision. Over the past half-century most rotorcraft research has focused on helicopter design, only viewing autorotation as a means of achieving emergency landings. In contrast, this project utilized early rotor theory to develop algorithms which can predict unpowered rotor performance across the entire flight envelope. To validate these predictions, a vertical wind tunnel capable of testing rotors up to 4 feet in diameter at descent rates of up to 25 ft/s was constructed. Emphasis was also placed on developing deployment sequences that would allow the system to achieve stable autorotation autonomously. By varying parameters such as blade pitch angle and rotor solidity, it is shown that in the proper configuration, rotor based systems can match and even surpass parafoils in areas such as descent rate and glide slope. The autogyro also has the added capability of varying its lift-to-drag ratio in flight while maintaining reasonable descent speeds, allowing for more precise control to the target. Possible deployment sequences are displayed, proving that relatively simple configurations can be brought into stable autorotation. The algorithms developed and vertical wind tunnel constructed for this project can be used to gain further knowledge of autogyro performance.
by Michael Oliver.
S.M.

La société humaine demeure toujours, et probablement plus que jamais, à la recherche des principes fondamentaux qui impliqueraient la réalisation de la société humaine de demain, système juste, libéral et humaniste, performant sur le plan socio-économique (basé sur les principes de la décentralisation, mais aussi ceux de la complémentarité et de la réciprocité, donc inévitablement cohérent dans son ensemble, et dont l'intégrité, la stabilité et la régulation seraient assurées par un cadre institutionnel, étique et politique adapté, ce qui en ferait une vraie société humaine du progrès, pros- père et humaniste, mais dont objectif suprême ne serait plus l'État ni le culte de l'argent, mais l'être humain). Dans ce contexte, l'environnement en tout sens, en tant que logique fondamentale et essentielle à l'existence et à la pérennité de l'espèce humaine, devient besoin et valeur incontournable, et synonyme de l'avenir. Et comme la vision théorique de la société autogérée, semblait pouvoir se rapprocher de ces critères, (par ses principes théoriques de base), son analyse plus approfondie, en tant qu'expérience ré- elle, semblait légitime. Pour évaluer la place de l'environnement dans le développement autogéré, il s'agissait donc de faire un bilan (basé sur une documentation exhaustive), de la situation et gestion environnementale yougoslave, des politiques et législations mises place. Compte tenu la diversité des facteurs définissant le contexte général de l'autogestion, analyser les causes et les conséquences de la fracture grandissante séparant deux logiques en présence: celle de la gestion réelle des biens naturels et espaces du pays, et celle de l'ambition audacieuse et vision théorique autogestionnaire (issue de ses principes de base), inconséquence qui empêchera le système autogéré, brisé par des contradictions, de développer globalement ses potentiels du progrès, par la multiplication des choix plus judicieux.

Orientador: João Gualberto de Cerqueira Luz
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
Made available in DSpace on 2018-07-25T02:23:48Z (GMT). No. of bitstreams: 1 Jorge_RogeriodaSilva_M.pdf: 6492918 bytes, checksum: 936a52dbed0525bd03dec5fc34ed1a15 (MD5) Previous issue date: 1999
Resumo: Esta pesquisa teve por objetivo a avaliação da reparação de enxerto ósseo do ilíaco em defeito de tamanho crítico na mandíbula de rato, histologicamente e por densitometria óptica de radiografias. Os animais deste estudo foram 25 ratos Wistar adultos. Sob anestesia geral foi realizado defeito ósseo bicortical no ramo direito da mandíbula, preenchido com enxerto da crista ilíaca. Os animais foram divididos em cinco grupos, com cinco ratos cada. Estes foram sacrificados após um, sete e 14 dias, um e três meses. As mandíbulas foram removidas, fixadas em formol e posteriormente radiografadas. As emi-mandíbulas direi tas foram descalcificadas e cortes foram obtidos e corados com hematoxilina e eosina. Inicialmente foi. notado processo inflamatório agudo ao redor do enxerto, o qual estava bem adaptado ao leito receptor. A maior parte do enxerto era formado por osso esponjoso, com amplo espaço medular ocupado por tecido hematopoêtico. Em seguida foi observada intensa neoformação óssea a partir da cortical mandibular e dentro do próprio enxerto. Os espaços medulares estavam ocupados por tecido de granulação e osteoblastos. Houve remodelamento do leito receptor, com diminuição do volume do enxerto e espaço medular, bem como substituição do osso esponjoso por osso compacto. Por fim, do enxerto, somente remanescentes corticais desvitalizados foram encontrados, estando o local do enxerto semelhante à mandíbula normal. A densitometria óptica das radiografias revelou diferenças estatisticamente significantes entre o lado experimental e controle. Este modelo experimental mostrou ser valioso no estudo da reparação óssea. Foi concluído que o enxerto do osso ilíaco promoveu a reparação do defeito crítico mandibular, com remodelamento ósseo completo
Abstract: The aim of this study was to eVa1uate the healing of critical SlZe defect in the rat mandible filled with iliac graft, histologically and by optical densitometry of radiographs. The study animals were 25 adult Wistar rats. Under general anesthesia a bicortical osseous defect was created in the right mandibular ramus, and filled with iliac crest graft. The animals were divided into five groups, with five rats in each. They were sacrificed after one, seven and fourteen days, one and three months. The mandibles were removed, fixed in formalin, andi later radiographed. The right hemi-mandibles were decalcified, and sections were cut and stained with hematoxilyn and eosin. Initially, acute inflammatory process was noted along the graft, which was tightly fitted to the defect. Subsequently, intense bone neoformation from external cortical's and in the inner spaces of the graft was observed. Medular spaces were occupied by granulation tissue and osteoblasts. There was remodelation of the receptor site,"with decrease in the graft volume and medulary space, as well as cancellous bone replaced by compact bone. Later, devitalized remnants of corticals of the graft were found, and receptor site was similar to the normal mandible. Optical densitometry of radiographs revealed statistically significant differences between experimental and control sites. This experimental model was valuable in the bone healing study. It was concluded that iliac graft promoted healing of the critical size defect of the mandible, with complete bony remodeling
Mestrado
Biologia e Patologia Buco-Dental
Mestre em Ciências

La pratique de l’autogestion en milieu scolaire et ses incidences tant pédagogiques que politiques font l’objet de cette monographie du Lycée Autogéré de Paris (LAP). Après une description des principes pédagogiques du LAP (libre fréquentation, gestion collective, évaluation collective associée au suivi personnalisé) et un examen des concepts d’institution et d’implication dans le cadre théorique de l’Analyse Institutionnelle, un schéma théorique est proposé pour décrire les relations didactiques. Le concept de Travail d’institutionnalisation (TDI) permet ensuite de décrire la spécificité de la pédagogie autogestionnaire, ses différences avec la Pédagogie Institutionnelle et sa conception particulière de la pratique de l’institution en tant qu’outil pédagogique. En tant que collectif autogéré, le LAP mène un TDI qui représente un double travail, à la fois sur les institutions internes et sur les institutions qui le traversent. Enfin, une monographie d’élève décrit les liens entre la participation des élèves au TDI et la conquête d’une autonomie de l’élève face à sa scolarité ainsi qu’à son travail scolaire. D’une part, l’élève qui désire participer à la gestion de son école se trouve confronté à la gestion de sa scolarité. D’autre part, les spécificités des relations didactiques et des procédés évaluatifs découlant de la gestion collective influent sur le rapport de l’élève à son travail dans les disciplines étudiées
The object of this monograph concerning the Autogestioned Lyceum of Paris (LAP) is the practice of autogestion in the school and its pedagogical and political implication. After a description of the pedagogical principals of LAP (free attendance, collective management, collective assessment associated with personalized tutoring) and a study of the institutions’ and implications’ theoretical concepts in the theoretical framework of Institutional Analysis, a theoretical scheme is proposed in order to describe teaching relations. The concept of institutionalisation work (IW) permits us to describe the particularity of pedagogical autogestion, its differences with Institutional pedagogy and its particular conception of practice on institution as a pedagogical tool. LAP, as a autogestioned collective, applies an institutionalisation work that represents a double task: on one hand concerning the internal institutions and on the other hand concerning the institutions that flow through it. Finally, the relations between the students’ participation in institutionalisation work and the acquisition of his autonomy facing his schooling and his school work is described in a students’ monograph. On one hand, the student that wants to participate in the schools’ management faces the self-management of his schooling. On the other hand, the particularities of teaching relations and the evaluative processes that emerge from collective management influence the students’ relation with his work in the subjects studied

Cette thèse étudie, à travers un film et un manuscrit, le fonctionnement pédagogique du Lycée autogéré de Paris, un établissement d’enseignement secondaire public et désectorisé. A l’issue d’une immersion de vingt mois, l’auteur interroge la façon dont se déploient les rapports de force entre personnes au sein de cette structure éducative se réclamant d’un fonctionnement horizontal, ainsi que leurs répercussions sur les apprentissages et sur des trajectoires d’élèves dans et après le lycée. Ce travail recouvre également une démarche réflexive à travers laquelle l’auteur questionne les ressorts épistémologiques de l’usage de la caméra en anthropologie
Through a movie and a written work, this dissertation studies the pedagogical functioning of Le lycée Autogéré de Paris, a public but self-managed high school in France. Following a twenty-month immersion, the author studies both how power dynamics function in an educational institution that claims to adhere to a horizontal organizational structure, as well as the consequences of said dynamics on the learning process inside the school and after graduation. Through a reflexive method, the author also questions the use of film in anthropology

Nel seguente lavoro di tesi sono stati ricercati i parametri di processo per la realizzazione di un giunto saldato su lamiere di acciai alto-resistenziali (AHSS) martensitici, mediante una sorgente Laser in continuo ad alta potenza. In particolare, è stato realizzato un confronto tra un processo di saldatura Laser convenzionale, il quale sfrutta l’elevata densità di energia del fascio laser senza l’impiego di materiale d’apporto ed un processo che invece utilizza del materiale d’apporto. Nel primo caso, lo studio si è incentrato sulla definizione dei parametri di processo in grado di poter realizzare un giunto di profondità pari allo spessore della lamiera ed esente dai principali difetti di saldatura come ad esempio può essere la presenza di porosità. Nel secondo caso, il materiale è stato depositato sotto forma di polvere metallica utilizzando un’applicazione particolare della tecnologia laser, normalmente non associata alle operazioni di saldatura massive: il cladding (o riporto) e, più nello specifico, mediante quella che viene identificata come operazione a deposizione diretta di polvere, o Direct Laser Deposition (DLD). In questo lavoro di tesi, tale tecnologia è stata sperimentata per la realizzazione di giunti saldati, analogamente alle operazioni di saldatura con materiale d’apporto nelle tecnologie di saldatura tradizionali. In particolare, attraverso un leggero scostamento tra le lamiere o delle piccole cianfrinature a “V”, in aggiunta all’elevato apporto energetico del fascio laser, è stato possibile riempire il giunto con la polvere metallica e dunque realizzare la giunzione. Nel caso in esame la polvere metallica è in acciaio inox austenitico, AISI 316L, caratterizzato quindi da proprietà anticorrosive piuttosto che alto-resistenziali come quelle del materiale base. Dunque, pur avendo caratteristiche differenti dal materiale base, questo può essere trattato come un riporto affine poiché entrambi risultano essere degli acciai.

Cette thèse porte sur un manuscrit appartenant à la Bibliothèque Nationale de Berlin : D-Bds Mus. Ms. Autogr. J. V. Meder 1. Il s'agit d'une partition d'une Passion-oratorio selon St. Mathieu qui, bien que conservée depuis 1850 parmi les sources très précieuses, n'a encore été l'objet d'aucune recherche. Or, la page de titre étant perdue, le compositeur, le lieu et la date de composition de l'unique source conservée sont inconnus. La thèse expose comment, à partir de l'analyse de la source (papier, encres, écritures), les trois versions contenues dans le manuscrit ont été mises à jour. Compte tenu de la représentation de l'oeuvre à Riga tout au long du 18ème siècle, l'étude du contexte historique de la Passion dans cette ville, révélée comme lieu de composition par les filigranes, a permis de déterminer le sens des versions apocryphes par rapport à l'original. La mise en perspective des caractéristiques matérielles avec les sources de l'époque, ainsi que la datation des mélodies de chorals du manuscrit ont finalement permis l'identification définitive de l'Actus Musicus de Passione Jesu Christi, composé par Johann Valentin Meder en 1716. Cette recherche réhabilite une Passion faussement identifiée et éditée dans les publications actuelles ( MGG, New Grove ou l'édition Das Chorwerk ). Elle constitue de ce fait le prélude d'une édition critique
This doctoral thesis is dedicated to a manuscript belonging to the Berlin National Library : D-Bds Mus. Ms. Autogr. J. V. Meder 1. Although it is classified among highly valuable sources since 1850, this score of a St. Matthew Oratorio-Passion hasn't been the subject of any research yet. Though, the title page being lost, the composer as well as the composition place and date of the unique remaining source were unknown. Basing on the analysis of the source (paper, inks and handwritings), this thesis sets out how the three versions forming this manuscript have been updated. Considering that the Passion has been performed in Riga throughout the 18th century, the study of the historical context of the work in that city, revealed as the actual place of composition by the watermarks, allowed to determine the meaning of the apocryphal versions in comparison to the original one. Lastly, the analysis of the materials characteristics in the perspective of the sources of that time, as well as the dating of the chorals melodies in the manuscript, permitted the final identification of the Actus Musicus de Passione Jesu Christi, composed by Johann Valentin Meder in 1716. This research restores to favour a Passion that is wrongly identified and edited in current publications (MGG, New Grove or Das Chorwerk edition), making it therefore the prelude to a critical edition

Orientador: José Mauro Granjeiro
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: O objetivo do trabalho foi avaliar comparativamente a neoformação óssea e o perfil de gelatinases 2 e 9 durante o reparo de defeito crítico em crânio de ratos tratados com osso autógeno ou xenoenxerto desmineralizado. Um defeito ósseo de tamanho crítico (8 mm) foi confeccionado no crânio de 90 ratos Wistar (90 dias de vida), e preenchido com osso autógeno (grupo controle) obtido durante a confecção do defeito ou com matriz óssea bovina desmineralizada (grupo teste). Após os períodos de 7, 14, 21, 30 e 90 dias, os animais foram eutanasiados e as peças coletadas para análises histomorfométrica (em hematoxilina e eosina) e zimográfica. A análise paramétrica foi realizada utilizando análise de variância (teste de Tukey se p<0,05). O completo fechamento do defeito no grupo controle foi observado aos 90 dias com a neoformação óssea ocorrendo das bordas do defeito para o centro e da dura-máter para epiderme. No grupo teste houve atraso no processo de reparo, ossificação incompleta e substituição das partículas do biomaterial por tecido conjuntivo fibroso, após 21 dias. Nos primeiros 14 dias após a cirurgia o infiltrado inflamatório predominante era composto de células mononucleares e poucas células gigantes multinucleadas. A análise zimográfica demonstrou que a atividade MMP-2 e -9 foram significativamente maiores no grupo teste que no grupo controle (p<0,05), sendo que a atividade MMP-2 manteve-se elevada até o período de 14 dias no grupo teste. A despeito da biocompatibilidade do xenoenxerto, o biomaterial não foi capaz de promover a neoformação óssea no defeito, possivelmente devido ao intenso estímulo da atividade gelatinolítica, em particular da MMP-2, que pode ter mediado a reabsorção prematura da matriz óssea bovina desmineralizada
Abstract: The purpose of this study was to evaluate comparatively new bone formation and the profile of the gelatinases 2 and 9 during the repair of critical size defects treated with autogenous bone or demineralized xenograft. A critical defect (8mm) was created in the skull of 90 Wistar rats (90-day-old) and treated with autogenous bone (control group) obtained during the confection of the defect or demineralized bovine bone (experimental group). After at 7, 14, 21, 30 and 90 days, the animals were killed and the calvaria removed for morphometric (stained by hematoxylin-eosin) and zymografic analysis. Parametric analysis was realized with analysis of variance (Tuckey¿s test if p<0.05). The control group showed complete closure of the defects at 90 days with new bone formation occurring from the sides towards the center of the defect and from the dura-mater outwards to the epidermis. In the experimental group, there was a delay in the process of repair, incomplete ossification and nearly complete substitution of material particles by fibrotic connective tissue after 21 days. At 14 days post-operatively, the inflammatory infiltrate consisted predominantly of mononuclear cells and few multinuclear giants cells. Zymografic analysis demonstrated that the activities of MMP-2 and -9 were significantly higher in the experimental group than in the control group (p<0.05), in addition the activity of MMP-2 was increased up to 14 days in control group . Despite the biocompatibity of the xenograft, the biomaterial was not capable to promote new bone formation in the defect. This might be possibly related to the intense stimulation of the gelanolitic activity, in particular of MMP-2, which in turn may have mediated the resorption of the demineralized bovine bone
Doutorado
Bioquimica
Doutor em Biologia Funcional e Molecular

Cette thèse s’intéresse aux capacités des citoyens, en France, à agir collectivement et à impulser des productions « alternatives » de leur cadre de vie et de leur cadre habité. Fondées largement sur une critique des modes de production conventionnels, ces démarches en proposent un dépassement dans une perspective de mutualisation et de solidarité. Si elles se réclament d’expériences étrangères, elles s’inscrivent en même temps dans la poursuite d’un débat tant idéologique qu’opérationnel qui a parcouru le XX° siècle sur la participation des habitants à la production de l’habitat. En portant notre regard sur une série d’initiatives qui ont émergé au début des années 2000, nous analysons leurs modalités de structuration, d’organisation collective et d’interpellation de l’action publique. Ces mobilisations qui sont portées par des acteurs associatifs, politiques et institutionnels construisent ainsi le Monde de « l’habitat participatif ». Pour mieux saisir ce mouvement contemporain, nous nous sommes penchée sur l’héritage des expériences françaises de l’habitat groupé autogéré de la fin des années 1970. L’approche diachronique de l’enquête questionne les niveaux de filiation entre les initiatives d’hier et celles des années 2000. Cette analyse montre comment s’organisent ces militants et les stratégies qu’ils adoptent pour faire entendre leur revendication. Elle met en évidence les mécanismes d’élaboration d’une question publique et son traitement par des acteurs institutionnels. Cette thèse contribue à l’analyse de la transformation de l’action publique et questionne les capacités de co-construire et de dialogue entre initiative militante et acteurs institutionnels
This thesis focuses on the capacity of citizens to collectively promote “alternatives” in terms of living and housing environments in France. Grounded in a broad critique of conventional modes of production, the study suggests ways of transcending these modes through social processes such as sharing and solidarity. Although many such experiments have occurred outside of France, they are linked to ongoing twentieth century ideological and operational debates about resident participation in the construction of their own housing. By closely examining a series of initiatives in the early 2000s, the present study analyzes how they were organized and structured and how they generated public action. Under the auspices of housing associations and political and institutional organizations, these mobilizations have collectively supported the construction of a World of “participative housing.” In order understand this contemporary movement in an historical perspective, the study has also investigated the legacy of self-managed housing projects in France in the late 1970s. This diachronic approach helps to critically appraise relationships between earlier initiatives and more recent examples in the early 2000s. The study demonstrates how activists organized themselves; it analyses the strategies they used to ensure their demands would be heard. It highlights the mechanisms through which this public issue was created and describes its reception by a range of institutional actors. This thesis contributes to an analysis of the transformation of public action. It questions the capacities to co-construct and to drive a dialogue between activist initiatives and institutional actors

Cette thèse analyse l’histoire de l’autonomie des élèves comme idéal et comme pratique pédagogique au sein de l’enseignement public français de 1959 jusqu’à nos jours à partir de l’étude de deux établissements singuliers : l’École Vitruve et le Lycée Autogéré de Paris. Notion polysémique, aux multiples définitions et aux contours fluctuants, nous avons fait le choix d’analyser l’autonomie dans le domaine éducatif. À partir d’un plan chronologique, nous avons étudié l’autonomie comme une référence de l’Éducation nouvelle, une vision idéalisée de l’éducation, un levier de transformation sociale, une pratique de classe et une finalité éducative.Dans une démarche socio-historique, à partir des archives des établissements et d’entretiens, nous avons pu étudier les discours et les pratiques mises en œuvre depuis la création de ces établissements qui ont fait le choix de faire de l’autonomie la colonne vertébrale de leurs projets. Nous avons pu préciser le rôle de Robert Gloton dans cette dynamique. L’étude des liens entre ces deux expériences spécifiques et l’institution scolaire nous est apparue révélatrice de certaines mutations du système éducatif public français. Dans cette étude l’autonomie apparaît bien comme un idéal toujours présent dans l’éducation, mais aussi une question socialement vive avec une définition toujours sujette à controverses et débats. Néanmoins, l’autonomie comme finalité éducative, reste un enjeu primordial de compréhension des débats actuels et futurs
This thesis analyses the history of student’s autonomy as an ideal and pedagogical practice within French public education from 1959 to the present day, based on the study of two singular educational institutions: the Ecole Vituve and the Lycée Autogéré de Paris. A polysemous notion, with multiple definitions and fluctuating contours, we have chosen to analyse autonomy in the educational field. Based on a chronological plan, we studied autonomy as a reference for the New education, an idealized vision of education, a lever for social transformation, classroom practice and an educational finality. In a social-historical approach, based on the archives of the institutions and interviews, we were able to study the discourses and practices implemented since the creation of these institutions, which have chosen to make autonomy the backbone of their projects. We were able to clarify Robert Gloton's role in this dynamic. The study of the links between these two specific experiences and the school institution seemed to us to reveal certain changes in the French public education system. In this study, autonomy appears to be an ideal that is always present in education, but also controversial issue with a definition that is always subject to controversies and debates. Nevertheless, autonomy as an educational goal remains a main issue in understanding current and future debates

Orientador: Pedro Duarte Novaes
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
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Resumo: O objetivo deste trabalho foi analisar histologicamente e histometricamente a técnica de Regeneração Óssea Guiada (ROG) associada ou não ao enxerto ósseo autógeno e ao carbonato de cálcio natural pulverizado sobre o processo de reparo ósseo, nos defeitos bicorticais confeccionados, em calvária de ratas. Foram utilizadas 60 ratas adultas, em cada calota foram realizados 2 defeitos circulares de 4mm de diâmetro, sendo um do lado direito e outro do lado esquerdo da sutura sagital mediana. Os animais foram divididos aleatoriamente em seis grupos: grupo I controle; II enxerto ósseo autógeno; III carbonato de cálcio natural pulverizado; IV recebeu membrana de colágeno absorvível nas corticais ósseas interna e externa; V carbonato de cálcio entre as membranas de colágeno e VI enxerto ósseo autógeno entre as membranas. Os animais foram sacrificados nos períodos pós-operatórios de 14 e 28 dias. O material coletado foi analisado através de microscopia de luz e de luz polarizada. Os reultados histológicos sugeriram que no período de 14 dias o material que promoveu maior osteogênese foi o do grupo do osso autógeno e no período de 28 dias foi o grupo osso autógeno associado à membrana de colágeno. O carbonato de cálcio natural exibiu reação inflamatória de corpo estranho intensa e quando associado à membrana de colágeno houve formação de abcesso. Os resultados deste estudo demonstraram que o enxerto ósseo autógeno associado às membranas de colágeno exibiram reparo ósseo significantemente maior quando comparado aos outros grupos
Abstract: The purpose of this study was to analyse histogically and histometrically the Guided Bone Regeneration (GBR) associated or not with autogenous bone graft and natural granular calcium carbonate in the treatment of a bicortical osseous defects created in rats skull. Sixty adult female rats received bilateral 4 mm trephine defects in the parietal area. The animals were assigned to one of following: group 1- control procedure; II- autogenous bone graft; III- natural granular calcium carbonate; IV - collagen membrane placed ecto-endocranially; V - calcium carbonate between collagen membranes and VI- autograft between collagen membranes. The animal were killed 14 and 28 days after surgery. The results were assessed by light and polarization microscopy. The best results as for bone regeneration was observed at 14 days with autogenous bone graft without collagen membranes and at 28 days with autograft between membranes. Natural granular calcium carbonate showed severe foreign-body inflammatory reaction and when associated with collagen membranes abcess formation was observed. The results of this study demonstraded that autogenous bone graft associated with collagen membranes exhibited significantly better bone healing as compared to another groups
Mestrado
Mestre em Biologia e Patologia Buco-Dental

碩士
國立臺灣科技大學
電機工程系
101
This study puts forward a new application of energy conservation—using the theorem of regenerative braking of brushless DC motor (BLDC motor) for autogyro. The idea is because the rotor of an autogyro is auto-rotated in the flight stage, some energy of the rotation may be recovered for energy conservation. In our study, in order to emulate the flight situation of an autogyro to test the function of the main rotor, an emulated wind field is required. Thus, we have built such an emulation system. Besides, in our study, the energy about level flying and decline is also observed and the control system is built to test the performance of the regenerative braking system. As the result of the emulation, it is known that at some attitude, recover energy is feasibility. From the emulation, the feasibility of the opinion was confirmed. It is found that the energy is hard to recover when the autogyro flies level, but when it declines with level attitude, regenerative braking theorem can be used.

While wind energy has emerged as a popular source of renewable energy, the traditional wind turbine has an inherent limitation, namely that it only generates power in the presence of sufficiently high and consistent wind speeds. As a result, wind farms are typically built in areas with a high probability of the required wind speeds, which are geographically sparse. One way of overcoming this drawback is to tap into the energy available in winds at high altitudes which are not only consistent and of high magnitude, but also globally pervasive. An airborne wind energy device based upon the phenomenon of autorotation could potentially be used to exploit the abundance of wind of energy present at high altitudes. The work in this thesis first presents our study of a tethered-airfoil system as a candidate airborne wind energy (AWE) system. A mathematical model was used to show the feasibility of energy capture and the stability of the device in a wind field. Subsequently, the research identified the principle of autorotation to be better suited for high altitude energy harvesting. To this end, the thesis first presents a theoretical basis of the principle of autorotation, which is developed from existing models in literature. The model was adapted to predict aerodynamic conditions when used for harvesting energy. Encouraging simulation results prompted the main emphasis of this thesis, namely design of an experimental framework to corroborate the theory. Several experiments were devised to determine basic performance characteristics of an autogyro rotor and the data from each experiment is presented. A lab-scale experimental setup was developed as part of this thesis. The setup, consisting of a flapping-blade autogyro rotor and sensors, was used to acquire preliminary aerodynamic performance data. It is envisioned that refinements to this setup will ultimately provide a means of directly comparing analytical and experimental data. In this regard, we provide conclusions and make comments on improvements for future experiments.
M.S.M.E.
Masters
Mechanical and Aerospace Engineering
Engineering and Computer Science
Mechanical Engineering; Mechanical Systems Track

Wind turbines have been used for decades to harvest wind energy. They are suitable only to work on close to ground, and have several drawbacks that are related to the availability of the wind and the amount of extracted power compared with the cost of construction. On the other hand, there is an abundant wind power that is available at high altitudes. The wind jet streams at high elevations 8 - 12 kms are pervasive and persistent, and can potentially produce immense wind energy. Even at moderate elevations of 4 - 5 kms, wind power densities are much higher than on ground and more consistent. Consequently, in this thesis research, we investigate the topic of harvesting energy from high altitudes. First, we provide a comprehensive review of two existing theoretical methods that are proposed for airborne wind energy harvesting, the tethered airfoil, and the static autogyro. The latter approach has inherent advantages that warrant further investigation. Autorotation is a well-known phenomenon where a rotor sustains its angular velocity and maintains significant lift in the presence of strong aerodynamic forces and torques generated by interaction with a strong wind field. Autorotation has been researched in the context of free descent of helicopters but has not been considered for energy harvesting. Existing models have mainly focused on statics analysis. In this research, we propose a simple dynamic model of the Autogyro, with the goal of ultimately realizing an Autorotation Energy System (AES). The focus of our work is to provide a preliminary dynamic analysis of autorotation, which is largely absent in current literature, to explore the possibility of using autorotation for designing a multipurpose system that can simultaneously fly at high altitudes and generate energy from the wind. The proposed preliminary dynamic model is used to generate a simulation platform, which is used to explore the autogyros rudimentary maneuvers. Extensive simulation results are provided to evaluate the dynamic performance of AES. Energy harvesting analyses and results are also presented. It is expected that the results will guide the choice of actuations and control that will be necessary for generating combined autorotation and powered flights that would be net energy generating or energy efficient. The research will be relevant for both tethered and untethered AES and could also be incorporated into multi-rotor based UAVs such as quadrotors.
M.S.M.E.
Masters
Mechanical and Aerospace Engineering
Engineering and Computer Science
Mechanical Engineering; Mechanical Systems Track

abstract: An airborne, tethered, multi-rotor wind turbine, effectively a rotorcraft kite, provides one platform for accessing the energy in high altitude winds. The craft is maintained at altitude by its rotors operating in autorotation, and its equilibrium attitude and dynamic performance are affected by the aerodynamic rotor forces, which in turn are affected by the orientation and motion of the craft. The aerodynamic performance of such rotors can vary significantly depending on orientation, influencing the efficiency of the system. This thesis analyzes the aerodynamic performance of an autorotating rotor through a range of angles of attack covering those experienced by a typical autogyro through that of a horizontal-axis wind turbine. To study the behavior of such rotors, an analytical model using the blade element theory coupled with momentum theory was developed. The model uses a rigid-rotor assumption and is nominally limited to cases of small induced inflow angle and constant induced velocity. The model allows for linear twist. In order to validate the model, several rotors -- off-the-shelf model-aircraft propellers -- were tested in a low speed wind tunnel. Custom built mounts allowed rotor angles of attack from 0 to 90 degrees in the test section, providing data for lift, drag, thrust, horizontal force, and angular velocity. Experimental results showed increasing thrust and angular velocity with rising pitch angles, whereas the in-plane horizontal force peaked and dropped after a certain value. The analytical results revealed a disagreement with the experimental trends, especially at high pitch angles. The discrepancy was attributed to the rotor operating in turbulent wake and vortex ring states at high pitch angles, where momentum theory has proven to be invalid. Also, aerodynamic design constants, which are not precisely known for the test propellers, have an underlying effect on the analytical model. The developments of the thesis suggest that a different analytical model may be needed for high rotor angles of attack. However, adding a term for resisting torque to the model gives analytical results that are similar to the experimental values.
Dissertation/Thesis
Masters Thesis Mechanical Engineering 2019

Réalisé au sein de l'IRCAM, en cotutelle avec Philippe Leroux. La version intégrale de cette thèse est disponible uniquement pour consultation individuelle à la Bibliothèque de musique de l’Université de Montréal.
« Vers une musique autogérée », est un regard sur mes œuvres des trois dernières années : un quatuor à cordes, un quatuor pour flûte basse, saxophone baryton, percussion et piano, une pièce pour voix de femme et douze musiciens et une pièce pour silent piano et dispositif électronique, qui sera le chapitre le plus exhaustif. Tout au long de cette étude, on examinera les notions qui m’inspirent, les points de départ de chaque pièce ainsi que les moyens employés pour arriver au bout de chaque idée. On parlera du tandem « intuition – processus » et comment il s’exprime chaque fois de façon différente, des réseaux qui se créent dans la musique, on abordera le concept omniprésent de l’incompatibilité et les relations que cela autorise, et on suivra l’évolution progressive de l’écriture vers une musique qui se veut « autogérée », en examinant comment ce terme se manifeste, selon les différents contextes.
« Towards an autoregulated music » is a look on my works of the past three years: a string quartet, a quartet for bass flute, baritone saxophone, percussion and piano, a work for female voice and twelve musicians and a piece for silent piano and real time electronics, the most thorough chapter. Throughout this study, we’ll examine the notions that inspire me, every piece’s starting points and the means applied to take every idea to its full potential. We’ll talk about the tandem « intuition – process » and how it’s expressed every time in a different way, the networks that exist in the music, we’ll approach the ever-present concept of incompatibility and the relations it allows, and we’ll follow the gradual evolution of the writing towards a music that calls itself « autoregulated », considering how this term is expressed, in different contexts.