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Dissertations / Theses on the topic 'Lasar'

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Published: 4 June 2021

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Rezende, Olga Scartezini de. "Diálogos culturais: Heitor dos Prazeres e Lasar Segall." Universidade Presbiteriana Mackenzie, 2018. http://tede.mackenzie.br/jspui/handle/tede/3475.

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Submitted by Eliana Barboza (eliana.silva1@mackenzie.br) on 2018-03-08T14:41:34Z No. of bitstreams: 2 Olga Scartezini de Rezende.pdf: 13569514 bytes, checksum: 76c88e28bb20c2a8a59bc84412c8b6c1 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Approved for entry into archive by Paola Damato (repositorio@mackenzie.br) on 2018-03-20T15:07:25Z (GMT) No. of bitstreams: 2 Olga Scartezini de Rezende.pdf: 13569514 bytes, checksum: 76c88e28bb20c2a8a59bc84412c8b6c1 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Made available in DSpace on 2018-03-20T15:07:25Z (GMT). No. of bitstreams: 2 Olga Scartezini de Rezende.pdf: 13569514 bytes, checksum: 76c88e28bb20c2a8a59bc84412c8b6c1 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-02-06 From a wide immersion in processes of cultural mediation coordinated by the educational area of the museums: Afro-Brazil, Lasar Segall and Museum of Contemporary Art of the University of São Paulo, the research investigated the cultural dialogues present in the works of Heitor dos Prazeres and Lasar Segall and the respective syntheses of their artistic productions against the asymmetric cultural exchanges of the society in which they interacted and left their legacy. By deeply intertwining the artistic productions of both with the social contexts involved, interdisciplinary bridges were established between the disciplines of Education, Art and History of Culture, as well as the use of various artistic languages for the development of the narrative, such as photography, painting, poetry, personal testimonies of the artists, reports of the time, and extensive literature, which, taken as a whole, were treated as relevant historical documents Based on the common culture thinking of Raymond Williams who understands culture as a process that engenders a whole way of life of a society as a socio-cultural experience with forms of sociability and also of resistance existing in residual and counter-hegemonic alternatives, the analysis of research has therefore distanced itself from any elitist and intellectual pattern that separates the idea of culture from other spheres that involve the set of human practices that are lived and related to society as a whole. Within this theoretical context, the research selected certain cuts in the artistic production of Heitor dos Prazeres and Lasar Segall due to their contributions in the reiterated debate between socio-cultural legacy and creative production in favor of a society that considers human diversity and the incorporation of otherness in its own dynamics of construction and reconstruction. A partir de uma ampla imersão em processos de mediação cultural coordenados pela área educativa dos museus: Afro-Brasil, Lasar Segall e Museu de Arte Contemporânea da Universidade de São Paulo, a pesquisa investigou diálogos culturais presentes nas obras de Heitor dos Prazeres e Lasar Segall e as respectivas sínteses de suas produções artísticas diante das trocas culturais assimétricas da sociedade na qual interagiram e deixaram seu legado. Ao entrelaçar de modo profundo as produções artísticas de ambos com os contextos sociais envolvidos, estabeleceu-se pontes interdisciplinares entre as disciplinas de Educação, Arte e História da Cultura, como também, lançou-se mão de diversas linguagens artísticas para o desenvolvimento da narrativa, como: a fotografia, a pintura, a poesia, depoimentos pessoais dos artistas, reportagens da época, além de extensa literatura, que, em seu conjunto, foram tratados como relevantes documentos históricos. Com base no pensamento de cultura comum de Raymond Willians que compreende a cultura como um processo que engendra todo um modo de vida de uma sociedade enquanto uma experiência sociocultural com formas de sociabilidade e também de resistência existente em alternativas residuais e contra hegemônicas, a análise da pesquisa se distanciou de qualquer padrão elitista e intelectual que separe a ideia de cultura de outras esferas que envolvem o conjunto de práticas humanas que são vividas e relacionadas com a sociedade como um todo. Dentro desse contexto teórico, a investigação elegeu certos recortes da produção artística de Heitor dos Prazeres e Lasar Segall devido às suas contribuições no reiterado debate existente entre legado sociocultural e produção criativa em prol de uma sociedade que considere a diversidade humana e a incorporação da alteridade em sua própria dinâmica de construção e reconstrução.

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Cardoso, Juliana Vilar Rodrigues. "Uma criatura dócil, de Dostoiévski: a leitura de Lasar Segall." Universidade Presbiteriana Mackenzie, 2012. http://tede.mackenzie.br/jspui/handle/tede/2161.

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Made available in DSpace on 2016-03-15T19:45:41Z (GMT). No. of bitstreams: 1 Juliana Vilar Rodrigues Cardoso.pdf: 3687764 bytes, checksum: bc551d05b01bc005918918610d65d400 (MD5) Previous issue date: 2012-08-15 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior The relationship between literature and the visual arts is very old and can be found in recreations such as the images made by Delacroix for Goethe s Faust and by Flaxman for Dante s The Divine Comedy. Lasar Segall s lithographs inspired by the short story A gentle creature, by Fyodor Dostoevsky, show that this relationship is still relevant in the twentieth century. The objective of this research is to analyse Dostoevsky s short story and Segall s lithographs and observe the language that each of these artists used to create characters who express their own inner world. Based on the concept of self-awareness developed by Mikhail Bakhtin, we will observe the construction of the short story s main character, which is a man who is distant from reality but finally realizes the truth about himself. We will also discuss the way in which Lasar Segall, who at the time was part of the German Expressionist movement, uses Dostoevsky s text to produce his lithographs, or more specifically, we will analyze the graphic elements used by him to convey the inner world of the characters and the tragic aspect found in the short story. A relação entre a literatura e as artes visuais é muito antiga e pode ser observada em recriações como as imagens feitas por Delacroix para Fausto, de Goethe, e por Flaxman para A divina comédia, de Dante. As litografias de Lasar Segall, inspiradas na novela Uma criatura dócil, de Fiódor Dostoiévski, demonstram que essa relação continua de forma marcante no século XX. O objetivo desta pesquisa é, a partir da análise dialógica entre a referida novela de Dostoiévski e as litografias de Segall, observar a linguagem que cada um desses artistas utilizou para criar personagens que expressassem seu próprio mundo interior. Nesse processo investigativo, será examinado como ocorre a passagem de uma linguagem para outra, tendo, como fundamentação teórica, os estudos da Intermidialidade. Partindo do conceito de autoconsciência elaborado por Mikhail Bakhtin, observaremos a construção da personagem principal da novela, que é um homem que se encontra no limiar, bem como sua trajetória, que passa pela confissão e pelo arrependimento, para, finalmente, chegar à verdade sobre si mesmo. Discutiremos, ainda, a maneira como Lasar Segall, que nesta época fazia parte do movimento Expressionista alemão, utiliza o texto-fonte de Dostoiévski para produzir suas litografias, ou mais especificamente, iremos analisar os elementos gráficos por ele utilizados para transmitir, imageticamente, o mundo interior das personagens e o caráter trágico encontrados na novela.

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Agostinho, Júlia Marino. "Navio de emigrantes de Lasar Segall: uma visão da arte dentro da diáspora." Pontifícia Universidade Católica de São Paulo, 2011. https://tede2.pucsp.br/handle/handle/12656.

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Made available in DSpace on 2016-04-27T19:30:14Z (GMT). No. of bitstreams: 1 Julia Marino Agostinho.pdf: 7472623 bytes, checksum: db6532dcc303850a67815584fd1bce39 (MD5) Previous issue date: 2011-05-06 The objective of this essay is to understand the social-historical aspect of the work of art Navio de Emigrantes [Ship of Emigrants] by Lasar Segall, an artist born in Vilnius, Lithuania, naturalized Brazilian citizen. The work of art, besides showing its power, as it is impossible to determine an artistic line due to its being always contemporaneous, allow us a visual and material contact with our own selves. Thus, as we cannot be detached from it, this dissertation presents and discusses the intrinsic relationship between art and society, based on a frame constructed through a contemporaneous fact: the Diaspora Este trabalho objetiva a compreensão histórico-social da obra de arte intitulada Navio de Emigrantes, do artista Lasar Segall, nascido em Vilna e naturalizado brasileiro. A referida obra de arte, por ser contemporânea, mostra seu poder ao não permitir que se lhe atribua uma determinada linha artística. Também deve ser considerada a impossibilidade de um distanciamento entre a obra e seus espectadores visto que ela estabelece com eles um contato visual e material. Por esse motivo, nesta dissertação é apresentada e discutida a relação intrínseca entre arte e sociedade com base em um quadro construído através de um fato contemporâneo: a diáspora

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Lasar, Christian [Verfasser], Thorsten [Akademischer Betreuer] Klüner, and Martin [Akademischer Betreuer] Holthaus. "Explicitly correlated orbital optimized contracted pair correlation methods / Christian Lasar ; Thorsten Klüner, Martin Holthaus." Oldenburg : BIS der Universität Oldenburg, 2018. http://d-nb.info/1161845631/34.

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Bethge, Mareike Katja [Verfasser], Martin [Gutachter] Brüne, and Michael [Gutachter] Lasar. "Soziale Kognition bei Zwangsstörungen / Mareike Katja Bethge ; Gutachter: Martin Brüne, Michael Lasar ; Medizinische Fakultät." Bochum : Ruhr-Universität Bochum, 2018. http://d-nb.info/1167505093/34.

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Lima, Paulo José Nascimento. "Plano museológico: questões e proposições a partir do estudo de caso do Museu Lasar Segall." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/103/103131/tde-09022015-111246/.

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O presente trabalho tem o intento de apresentar questões e proposições na construção de planos museológicos a partir das experiências do Museu Lasar Segall (MLS). No primeiro capítulo é apresentado o histórico do MLS, enfocando seu perfil museológico (escolhas conceituais) e suas práticas de gestão, assim como um paralelo de suas experiências com o pensamento museológico contemporâneo, e ainda um breve panorama com trabalhos acadêmicos que já foram realizados tendo o MLS como objeto. No segundo capítulo é descrito e apresentado o resultado do diagnóstico museológico que buscou mapear as funções e atividades do MLS hoje, sua cadeia operatória museológica, bem como sua relação com a sociedade. No terceiro capítulo, a partir dos anteriores, e permeando uma discussão sobre os processos de planejamento em museus, são apresentadas questões e propostas enfocando a construção de planos museológicos. This work aims to present issues and propositions for the museological plan elaboration from the Lasar Segall Museum (MLS)\'s experiences. In the first chapter is presented the MLS\'history, focusing its museological profile (conceptual choices) and their management practices, as well a parallel of their experiences with contemporary museological thinking, and even a brief overview with academic studies that had been conducted having MLS as a study object. The second chapter describes and presents the results of museological diagnosis that intent to map the MLS\' functions and activities nowadays, its museological operative chain as well its relationship with society. In the third chapter, from the previous ones, and permeating a discussion about the planning processes in museums, are presented issues and proposals focusing on museological plan elaboration.

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Sela, Svea Mareike [Verfasser], Boris [Gutachter] Schiffer, and Michael [Gutachter] Lasar. "Zwangsbehandlung bei schizophrenen Patienten im hessischen Maßregelvollzug / Svea Mareike Sela ; Gutachter: Boris Schiffer, Michael Lasar ; Medizinische Fakultät." Bochum : Ruhr-Universität Bochum, 2021. http://d-nb.info/123834657X/34.

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Lasar, David Verfasser], Angelika [Akademischer Betreuer] [Schnieke, and Martin [Akademischer Betreuer] Klingenspor. "The developmental role of brown adipose tissue and brown-like adipocytes (brite) in murine neonates / David Lasar. Gutachter: Angelika Schnieke ; Martin Klingenspor. Betreuer: Martin Klingenspor." München : Universitätsbibliothek der TU München, 2014. http://d-nb.info/105947722X/34.

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Reis, Magali dos. "A imagem e semelhança : um estudo sobre a imagem da criança nas pinturas de Eliseu Visconti, Vicente do Rego Monteiro, Tarsila do Amaral e Lasar Segall." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/252136.

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Orientador: Elisa Angotti Kossovitch Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Educação Made available in DSpace on 2018-08-09T10:41:24Z (GMT). No. of bitstreams: 1 Reis_Magalidos_D.pdf: 9259963 bytes, checksum: 96abba94516a8bc653f74a60cdc42898 (MD5) Previous issue date: 2007 Resumo: O estudo analisa a imagem da criança nas pinturas de Eliseu Visconti, Vicente do Rego Monteiro, Tarsila do Amaral e Lasar Segall. Compreende o período de 1890-1940 (aproximadamente), cujo eixo de problematização está na emergência de um movimento político, artístico e cultural. O período registra uma profunda mudança não só no papel social da criança, como também de sua representação nas artes plásticas, na literatura, na educação e no imaginário social. A arte sugere um ensaio de modulação da afeccionalidade social sobre a infância, o que permite trabalhar com aspectos ainda pouco explorados, no que diz respeito à imagem de crianças. Na pintura crianças tornam-se anjos, meninas enlaçam-se e enlaçam a composição da obra, corpos repousam sobre lençóis, meninos transfiguram a inquietude da puerícia. As paisagens são permeadas pelos enigmas da infância. As imagens da criança não são retratos de uma certa infância, o que faz a sua força é que elas são imagens políticas e inseparavelmente imagens de um inconsciente social, e sob esta ótica, são registros de corpos sempre falados, descritos e analisados por adultos, não tendo voz própria, sobre as formas como vêm sendo interpretados, expressos, percebidos. A orientação desta pesquisa caminhou no sentido de evitar proceder a uma simples e arbitrária ¿leitura¿ ou descrição das imagens, rejeitando procurar nelas uma possível intencionalidade do artista em representar uma idéia pré-estabelecida de infância, e mais ainda foi preciso refutar a idéia de que a imagem 'reflete¿ a vida do artista e suas experiências. A produção de uma pintura cujo tema seja a criança, não significa que se possa depreender dela uma visão de infância ¿possível¿ daquele momento histórico social. Daí a necessidade de recorrer a história da arte e, sobretudo, encontrar uma metodologia de estudos adequada à compreensão da infância que a arte torna visível Abstract: This study analyses the image of children in the paintings of Eliseu Visconti, Vicente do Rego Monteiro, Tarsila do Amaral, and Lasar Segall. It encompasses the period of approximately 1890 to 1940, whose central line of problematics is the emergence of a political, artistic, and cultural movement. That period registers a profound change, not only in the social role of children, but also of their representation in the plastic arts, in literature, in education, and in social imagery. Art insinuates a test of modulation of social affectionateness on infancy, which permits that lesser explored aspects may be treated in regard to the image of children. Children in paintings become angels, little girls entwine themselves and become part of the composition of the painting, bodies lie on sheets, little boys transfigure the turbulence of childhood. Landscapes are permeated with the enigmas of infancy. Children¿s images are not portrayed with a defined infancy. What gives them strength is that they are political images, and images that are inseparable from social unconsciousness. It is through this perspective that they are records of bodies that are always talked about, and described and analyzed by adults, without manifesting through their own voices in regard to the forms that are being interpreted, expressed, and perceived. The orientation of this research advanced in the direction of avoiding a simple and arbitrary reading or description of the images, thereby rejecting the possibility of looking for any intention by the artist of presenting a pre-established idea of infancy. Even more so, it was necessary to refute the idea that an image reflects the life of the artist and his experience. The production of a painting whose theme is a child does not signify that it may infer the vision of a possible infancy at that historical social moment. Therefore, there is a need to resort to the history of art, and above all, find an adequate methodology of study for the comprehension of infancy that is made visible through art Doutorado Educação, Sociedade, Politica e Cultura Doutor em Educação

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Hilaire, Pierre. "Improved laser vibration ladar." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1998. http://handle.dtic.mil/100.2/ADA359857.

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Thesis (M.S. in Applied Physics) Naval Postgraduate School, December 1998. "December 1998." Thesis advisor(s): Robert C. Harney, Donald L. Walters. Includes bibliographical references (p. 43). Also available online.

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Tekelu, Geberetsadike Tegenne. "Modelling reactive transport of acid mine drainage in groundwater : Effect of geochemical processes spatially variable flow source location and distribution." Thesis, KTH, Industriell ekologi, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-32579.

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Impacts from mining waste deposits on groundwater resources have been recognized invarious parts of the world; though varied in scale depending on the composition of mineralsbeing mined, the level of technology employed and environmental commitment of thedevelopers. Mining activities usually involve milling, concentrating, and processing of oreswhich will result in a huge amount of waste, called tailings, usually deposited inimpoundments as a slurry, composed of fine grained geological material (uneconomicalminerals), chemicals utilized in the processs, and water. Oxidation of these deposits, usuallycontaining sulphide minerals, may result in generation of an acidic, metal laden leachate,callled Acid Mine Drainage (AMD), which may have a devastating impact on thesurrounding groundwater resources. In this study, the stochastic LaSAR-PHREEQC reactive transport modeling approach is usedin order to evaluate the coupled effect of geochemical reactions and physical heterogeneity ofthe subsurface in the breakthrough of acidity and metal downstream of the source while theAMD transported in the water saturated zone of an impoundment. The tailings depositcalled Impoundment 1 at the Kristineberg mining site at the Skellefteå field, in northernSweden, is used as a case study to simulate pH buffering processes and attenuation of Zn.The objectives of the study are 1) to evaluate the relevance of different possible geochemicalprocesses in pH buffering and Zn attenuation; 2) to evaluate the effect of spatial variability ofthe physical processes of the groundwater system on the breakthrough of contaminants; and3) to evaluate the effect of the location and distribution of the source zone in terms of thedistance from the impoundment boundary. Simulation results of the presented model revealed that pH buffering from calcite andchlorite are important processes capable of counteracting the acidification from AMD.Dissolution of secondary Al(OH)3(s) is another important process capable of buffering pH.Precipitation of smithsonite, ZnCO3, is an important process for attenuation of Zn2+.Moreover, sorption of Zn2+ on ferric iron surfaces is found to be an important process forattenuation of the metal, depending on the available sorption surface sites. Flow variabilityhighly affects the breakthrough of the contaminants such that with increasing subsurfaceheterogeneity, earlier breakthrough of contaminants occurs. Moreover, increased variabilityresults in decreased peak loads, but longer duration of the load. www.ima.kth.se

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Dulgergil, Ebru. "Development Of A Pulsed Fiber Laser For Ladar System." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614635/index.pdf.

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In recent years laser technology has increasingly developed with the use of fiber lasers and this has provided the possibility to implement different techniques in the defense industry. LADAR is at the forefront of these techniques. Fiber lasers constitute a perfect source for LADAR systems due to their excellent robustness, compact size and high-power generation capability. In this study we will explore the development of a pulsed fiber laser source for a LADAR system that can obtain high resolution 3D images in eye-safe region. A high power, all fiber integrated erbium system with strictly single mode operation in eye-safe region based on MOPA (master oscillator power amplifier) configuration with seed source and amplifier part was developed. Both the use of an actively mode locked laser with erbium doped fiber and fiber coupled modulated distributed feedback diode laser were investigated as seed sources for the amplifier part. Both erbium doped single clad fiber and erbium-ytterbium doped double clad gain fiber were used in this amplifier system. After amplification of the actively mode locked laser, 12 W of average optical power was obtained through single mode fiber with 1ns pulse duration at 10 MHz which corresponds to 1.2 kW peak power. For the fiber coupled DFB diode laser, 9.5W average power was obtained with around 8 ns duration pulses at 100 kHz and about 9.2 W average power was also obtained with around 700 ps duration pulses at 1 MHz through strictly single mode fiber at the output of the same amplifier system as was used in the actively mode locked seed source. In both cases calculated peak power was around 10 kW v which is estimated as the highest peak power for an all fiber integrated system with single mode operation. The development of such a fiber system with high power capability, compact size and free of misalignment is expected to be useful for LADAR application as well as other areas such as eye surgery, 3D silicon processing or any other material processing applications.

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Dunmeyer, David Richard 1978. "Laser speckle modeling for three-dimensional metrology and LADAR." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/16763.

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Thesis (M.Eng. and S.B.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2001. Includes bibliographical references (leaves 103-111). This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. In this thesis, I developed three-dimensional laser-speckle models to help in the development process of three-dimensional optical-metrology imaging systems. These models were developed to aid in the proof of concept for various three-dimensional metrology techniques. These models were then compared to real-world imaging systems, developed by both the author and other staff at the MIT Lincoln Laboratory, to determine their ability to accurately model said imaging systems. I also looked at the laser speckle statistics associated with mid-field systems in an exo-atmospheric environment as they relate to LADAR. by David Richard Dunmeyer. M.Eng.and S.B.

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Blanquer, Eric. "LADAR Proximity Fuze - System Study -." Thesis, KTH, Reglerteknik, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-106247.

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LADAR (Laser Detection and Ranging) systems constitue a direct extension of the conventional radar techniques. Because they operate at much shorter wavelengths, LADARs have the unique capability to generate 3D images of objects. These laser systems have many applications in both the civilian and the defence fields concerning target detection and identification. The extraction of these features depends on the processing algorithms, target properties and 3D images quality. In order to support future LADAR hardware device developments and system engineering studies, it is necessary to understand the influences of the phenomena leading to the final image. Hence, the modelling of the laser pulse, propagations effects, reflection properties, detection technique and receiver signal processinghave to be taken into account. A complete simulator has been developed consisting of a graphical user interface and a simulation program. The computer simulation produces simulated 3D images for a direct detection pulse LADAR under a wide variety of conditions. Each stage from the laser source to the 3D image generation has been modelled. It yields an efficient simulation tool which will be of help in the design of the future LADAR systems and gauge their performances. This master’s thesis contains the theoretical background about laser used to build the simulation program. The latter is described schematically in order to provide an insight for the reader. The graphical interface is then presented as a short user’s manual. Finally, in order to illustrate the possibilities of the simulator, a collection of selected simulations concludes the report.

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García, Vizcaino David. "Sistema láser de medida de velocidad por efecto doppler de bajo coste para aplicaciones industriales e hidrodinámicas." Doctoral thesis, Universitat Politècnica de Catalunya, 2005. http://hdl.handle.net/10803/6892.

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La utilización práctica del efecto Doppler en la emisión láser fue propuesta desde los inicios del desarrollo de los láseres en los años sesenta. Sólo en los años ochenta la investigación realizada pudo salir del laboratorio y dar lugar a la fabricación de aparatos de medida de velocidad comerciales. A partir de los noventa estos aparatos se popularizaron rápidamente. Actualmente se utilizan medidores de velocidad láser por efecto Doppler en múltiples aplicaciones, entre las que sobresale la medida de velocidad de fluidos, para estudios aéreo e hidrodinámicos. Sus características únicas, como la precisión obtenida en la medida, su alta resolución espacial y el carácter no intrusivo, sólo han comenzado recientemente a tener rivales de consideración, como pueden ser la velocimetría de imagen de partículas (PIV). También la medida de velocidades de móviles sólidos comienza a resultar, con el abaratamiento general de los componentes opto-electrónicos, un objetivo para muchas empresas. Entre las aplicaciones de este tipo se contemplan el control de velocidad de los vehículos en carretera y el control de procesos industriales del ramo textil, papelero y de empresas fabricantes de cables, entre otros. Empresas europeas y americanas, como Dantec Electronik y TSI, por citar las más representativas, comercializan aparatos LDA de propósito general de altas prestaciones. Hasta la fecha estos sistemas sólo podían ser adquiridos por importantes centros de investigación o grandes empresas, debido a su elevado coste. El futuro comercial de la velocimetría láser Doppler exige la fabricación de aparatos más económicos y adaptados a las necesidades del cliente. Muchos de los sistemas actuales son voluminosos, difíciles de manejar y con potencias de trabajo elevadas. Se está llevando a cabo un importante trabajo para conseguir reducir el tamaño y coste de los equipos sin perder sus principales prestaciones. Asimismo la alta velocidad y capacidad de cálculo de los ordenadores personales actuales debe hacer innecesaria la inclusión de procesadores específicos para estos equipos. Presentamos el diseño y construcción de un sistema integral de medida de dos componentes de la velocidad, sistema 2D-LDA, para aplicaciones industriales e hidrodinámicas de baja potencia. Siguiendo la filosofía delineada arriba, el diseño de nuestro sistema LDA fue realizado utilizando únicamente una fuente laser y un módulo detector. Los sistemas LDA de medida de dos componentes de velocidad comercialmente disponibles, por el contrario, emplean dos longitudes de onda óptica y dos fotodetectores independientes. Las emisiones azul y verde típicas de los láseres de ion-Ar son las longitudes de onda a menudo elegidas en este tipo de medidas. Por otra parte, se ha empleado los dos canales de entrada de una tarjeta de adquisición de uso general para realizar el disparo multinivel. Esta configuración permite trabajar en cada momento con la parte de señal burst teóricamente más adecuada, con mayor valor de relación señal a ruido. Este trabajo ha sido financiado por la CICYT Proyecto PETRI 95-0249-OP: REALIZACIÓN DE SISTEMAS LÁSER PORTÁTILES DE MEDIDA DE VELOCIDAD POR EFECTO DOPPLER (LDA-LDV) DE BAJO COSTE PARA APLICACIONES INDUSTRIALES E HIDRODINÁMICAS. The practical use of the Doppler effect at optical wavelengths was proposed at the early beginning of the development of the laser, in the sixties. However, it was only in the eighties when the results of the experimental work could finally get out of the laboratories, and the first Laser Velocimeters were commercially available. In the nineties this kind of systems became rapidly popular. Nowadays the Laser Velocimeters based on the Doppler frequency shift find a lot of important applications, especially in some industrial processes and in hydrodynamic and aerodynamic research. The unique characteristics of the Laser Doppler Velocimetry (LDV) only recently have encountered a rival technique in the Particle Image Velocimetry (PIV), for applications on fluids. The main features of LDV systems are the accuracy and the speed of the measurements, the high spatial resolution and, of course, the non-intrusive character of the technique. Moreover this kind of systems present advantages not only in fluid applications: actually it can compete with the microwave radar in the estimation of the velocity of solid targets. This becomes possible due to the progressive reduction of prices of optoelectronic devices and the improvement of its performances. The monitoring of the traffic velocity and the control of machinery in the manufacture of paper, wires and cables or thread can be mentioned among these applications. European an American companies, as Dantek Electronic or TSI, to mention the two most representative, commercialize high performance general-purpose LDV systems. Up to the date these instruments are sizeable and expensive, and its use requires some special training. There is not doubt that the future market of the LDV systems goes through a substantial decrease of prices and, indeed, through the possibility of custom-built designs. The potential number of users would increase then in an important manner. Many efforts are now being devoted by researchers in that direction. Moreover, the important improvement of capabilities of the desktop computers makes unnecessary the special electronic processors that, up to now, have been provided by the manufacturers of LDV systems as a part of them. In this Thesis the design and realization of a complete Laser Doppler Anemometer is presented. The system can measure two components of a fluid velocity (2D-LDA) and originally it was conceived to be used in industrial and hydrodynamics applications. Following the philosophy outlined above, the design of our LDA system was performed with only one laser source and one detector module. The common commercially available LDAs, on the contrary, designed to measure two components of velocity, use two different optical wavelengths and two independent photodiodes. On the other hand, a general-purpose acquisition card with two input channels has been used to implement a multilevel trigger. The configuration performed here permits to work in each moment with the part of the burst having the best signal to noise ratio. This work has been supported by the Spanish Government, CICYT project PETRI 95-0249-OP.

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Fabre, Grégory. "Influence des propriétés optiques et de l'endommagement de barrières thermiques EB-PVD pour la mesure d'adhérence par choc laser LASAT-2D." Phd thesis, Ecole Nationale Supérieure des Mines de Paris, 2013. http://pastel.archives-ouvertes.fr/pastel-00963742.

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Les barrières thermiques avec zircone EB-PVD pour les turbines aéronautiques sont soumises à des conditions extrêmes qui conduisent à l'écaillage du dépôt. La prévention de leur endommagement est donc nécessaire pour assurer l'intégrité des pièces. Afin de comprendre et de reproduire leur évolution dans une turbine, les barrières thermiques actuelles sont soumises à des essais longs de cyclage thermique. L'essai LASAT est un essai d'adhérence rapide à mettre en oeuvre qui se place en complément du cyclage thermique. L'impulsion laser appliquée sur la face nue de l'AM1 génère une onde de choc de compression qui se propage jusqu'à la surface libre de la zircone. La réflexion forme une onde de traction qui effectue le trajet inverse et peut rompre les interfaces qu'elle traverse. Le décohésion génère une tache blanche dans la zircone directement visible à l'oeil. Ce phénomène optique est élucidé en relation avec la microstructure de la zircone et la présence d'une fissure à l'interface. Pour connaitre le potentiel de l'essai, une large gamme d'échantillons avec différentes orientations du superalliage, quatre préparations de sous-couche, cinq microstructures de zircone et deux vieillissements thermiques ont été utilisés.Leur caractérisation a permis de les classer et de comparer leurs évolutions et leurs endommagements par cyclage thermique ou par LASAT. Le dimensionnement des fissures interfaciales par des méthodes non destructives a été réalisé par piézospectroscopie en exploitant les cartographies associées au signal defluorescence, par profilométrie et à partir de la tache blanche. Une approche simple et innovante exploitant et optimisant le comportement optique de la zircone est mise en place. Les tailles des fissures relevées ont mis en évidence le rôle des ondes 2D et permis la réalisation de l'essai LASAT-2D. Ici, ce n'est plus l'apparition de la fissure qui est recherchée, mais sa taille qui peut directement informer de l'adhérence à partir d'un seul choc laser. La modélisation numérique a confirmé le rôle de ces ondes 2D et leur potentield'utilisation par des abaques LASAT-2D. Ces courbes permettent de distinguer différentes préparations de barrières thermiques brutes d'élaboration ou vieillies. Un protocole complet est ainsi fourni pour le contrôle, la mesure et le suivi de la tenue mécanique de barrières thermiques sur des éprouvettes usuelles industrielles. Dans des essais complémentaires, le LASAT-2D a été appliqué en "face avant", avec le choc coté zircone, sur des éprouvettes et des pièces industrielles. Les mêmes tendances que pour le LASAT-2D développé dans cette thèse sont observées. Ceci autorise la perspective de l'application de cet essai et de cette méthodologie sur des formes complexes et fermées, telles les aubes de turbine.

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Sagnard, Maxime. "Detection of Weak Bonds in Bond ed CFRP Assemblies using Symmetrical LAser Shock Adhesion Test (S-LASAT)." Thesis, Paris, ENSAM, 2019. http://www.theses.fr/2019ENAM0022.

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L’une des grandes problématiques actuelles des secteurs aéronautique et spatial est la réduction du taux d’émission de CO2. Une des solutions est l’allègement et l’optimisation des structures. Dans cette optique, certains avions comme l’a380 ou l’a350 XWB ont été fabriqués en grande partie à l’aide de matériaux composites. Plus résistants et plus légers, ils permettent un gain de poids important comparés aux matériaux métalliques. Cependant, ces pièces composites sont encore assemblées à l’aide de rivets ou de boulons. Ces procédés non adaptés aux matériaux composites limitent le gain de poids que pourrait engendrer leur utilisation. L’emploi de colles en revanche permettrait ce palier à ce problème, permettant ainsi de réduire de manière plus efficace le poids des structures. Cependant, ce procédé peut aussi être à l’origine de la création de joints faibles. Un joint est qualifié de faible quand sa tenue mécanique est inférieure à sa tenue nominale prévue. Actuellement, l’absence de Control Non Destructif (CND) permettant d’évaluer les propriétés mécaniques de ces pièces collées est l’un des principaux verrous à l’utilisation de ce procédé d’assemblage.Le Test d’Adhérence par Choc Laser (LASAT) a déjà prouvé sa capacité à évaluer la tenue mécanique de joints de colle dans des structure en Polymère Renforcé de Fibres de Carbone (PRFC). Cependant il ne peut s’appliquer qu’à quelques géométries d’assemblage spécifiques et a aussi démontré des limites en termes de détection de joint faible. Ce travail propose une étude expérimentale et numérique d’une des optimisations du LASAT : le Test d’Adhérence par Choc Laser Symétrique (S-LASAT). Le but est d’approfondir la compréhension de la physique mise en jeu afin de mieux appréhender les prérequis nécessaires à la technologie pour détecter les joints faibles. Cette étude conclura sur une étude unique de test d’adhérence réalisée sur de vraies pièce aéronautiques collées The limitation of carbon dioxide emissions is one of today’s greatest challenges for the aerospace industry. Weight reduction is seen as one of the most promising lead for that matter and a first step has already been made toward this goal through the use of composite materials. Lighter and more mechanically efficient than their metallic counterparts, their use helped optimising the weight of several aircrafts such as the A350 XWB or A380. Nevertheless, if the material has changed, the assembly process did not evolve along with it. Hence, techniques such as riveting or bolting previously used for metallic structure are still used for composite parts assembly, but they are not suitable anymore for this type of material (creation of local constraints, corrosion, …). Instead, bonding composite parts using adhesives would be a better solution and could help further reducing the overall weight of the aircraft. However, with this new assembly method also come new problems, such as weak bonding. A weak bond is characterised by a loss of mechanical adherence that cannot be spotted using conventional Non-Destructive Tests (NDTs) such as ultrasound scanning. Since the industry currently lacks these NDTs to assess the mechanical integrity of bonded structures, the use of adhesives for composite assembly is limited.The LAser Shock Adhesion Test (LASAT), has already demonstrated its capacity to evaluate bonded composite assembly but also proved to be limited in terms of assembly configuration and weak bond detection capability. This work focuses on one of its optimisations, the Symmetrical LASAT (S-LASAT). Both experimental and numerical studies are realised to better understand the prerequisites of the technique as well as the level of mastery required for the technology to best detect weak bonds within Carbon Fibre Reinforce Polymer (CFRP) structures. This manuscript concludes with a one of a kind experimental campaign realised on real bonded CFRP aircraft parts

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Cruz, Livia Lara da. "Magistério e cultura: a formação cultural dos professores e sua percepção das potencialidades educativas dos museus de arte." Pontifícia Universidade Católica de São Paulo, 2008. https://tede2.pucsp.br/handle/handle/10688.

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Made available in DSpace on 2016-04-27T16:33:42Z (GMT). No. of bitstreams: 1 Livia Lara da Cruz.pdf: 585126 bytes, checksum: 1a0f6d82841535c71b036f9100ceb7e0 (MD5) Previous issue date: 2008-09-09 Secretaria da Educação do Estado de São Paulo This report of research has the objective of presenting an analysis of the collected data for the realization of a study that pretends to analyze the existent relations between the cultural formation of the basic school and high school teachers, that work at the public education system of São Paulo, and their perceptions of the art museums education potentiality. Having as main theoretical reference the french sociologist Pierre Bourdie and his concept of cultural capital, i intended to apprehend in which way the cultural formation of the teachers can or not determinate a better relationship with the art museums. For that reason, between the months of september and november of 2007 questionnaires were applied to two groups of distinct teachers considering their social origin, scholar and professional formation, information about habits of leisure, culture and opinion about museums and art exhibitions. The group 1 included twenty teachers, that scheduled spontaneously more than one visit with their students during the year of 2007, having monitorship to the Museu Lasar Segall, seated at the district of Vila Marina ( south area of São Paulo city). The group 2 included another twenty teachers, that scheduled visits to the Museu Lasar Segall having monitorship because of their school s participation at a project financed by the Secretary of Education of the State of São Paulo, and did not come back until the end of 2007. The results permitted to perceive the approximation between the two groups, especially about their social origin, but differences between their relation with the formation institution, the relation kept with state cultural objects and more specifically with the art museum. The teachers of the group 1(spontaneous) declared to have more access, since childhood, to cultural objects such as books, cinema, library and museum. The majority came from public universities of the state of São Paulo, these teachers could tell with more precision the name of the last book that they read or some of theirs favorites plastic artists; and they are also those that access internet more often, have already traveled to other countries and make visits to museums more frequently. The teachers of the group 2(project), whose access to cultural objects since childhood showed to be smaller, were students of private universities (some out of the state of São Paulo), had more difficulties to tell the name of last books that they read or the name of their favorite artists, they do not have access to the internet very often, and never traveled to other countries, and for two of them, the visit to the Museu Lasar Segall was the first visit to a museum. So, the aspect to be observed is to consider which is the importance of the formation institution (the public universities, being more traditional in academic aspects and privates that normally do not receive the same amount of importance in this area) has at the constitution of an habit of frequency at cultural areas; but it is fundamental to consider the importance that family action and, consequently, the cultural habits during the childhood have, the possibilities of them to have access to cultural objects when they are older, and the way that it is made. Considering the interviews that were realized with two teachers of the first group, it was possible to apprehend some strategies developed by families that, even not having much of scholar capital and cultural capital, contributed to an appropriation of the cultural objects for their children, being it to give more importance to the progress in school and what school represents, or being a bridge between a legitimate culture and their children Essa pesquisa tem por objetivo analisar as relações existentes entre a formação cultural dos professores do ensino fundamental II e médio da rede estadual de São Paulo e suas percepções acerca das potencialidades educativas dos museus de arte. Tendo como principal referencial teórico o sociólogo francês Pierre Bourdieu e seu conceito de capital cultural, pretendeu-se apreender em que medida a formação cultural dos professores pode ou não determinar uma relação mais fértil com os museus de arte. Para tanto, entre os meses de setembro e novembro de 2007 foram aplicados questionários acerca da origem social, formação escolar e profissional, informações sobre hábitos de lazer e cultura e opinião sobre museus e exposições de arte a dois grupos distintos de professores. O grupo 1 incluiu vinte professores que, durante o ano de 2007, agendaram espontaneamente mais de uma visita monitorada para seus alunos no Museu Lasar Segall, localizado no bairro da Vila Mariana, zona sul da cidade de São Paulo. O grupo 2 incluiu outros vinte professores, que agendaram visitas monitoradas no Museu Lasar Segall devido à participação da escola em um projeto financiado pela Secretaria da Educação do Estado de São Paulo e que não voltaram ao Museu até o fim de 2007. A análise dos resultados obtidos permitiu a percepção de aproximações entre os dois grupos no que diz respeito à sua origem social, mas diferenças em relação à instituição de formação e a relação mantida com os bens culturais de uma maneira geral, e mais especificamente, com o museu de arte. Os professores do grupo 1 (espontâneo) declararam ter um maior acesso, desde a infância, a bens culturais tais como livros, cinema, biblioteca e museu. Advindos majoritariamente de universidades públicas do Estado de São Paulo, esses professores puderam citar com mais precisão o nome do último livro lido ou alguns de seus artistas plásticos favoritos; são eles que acessam a Internet mais freqüentemente, já viajaram para outro país e visitam museus com mais freqüência. Os professores do grupo 2 (projeto), cujo acesso aos bens culturais desde a infância mostrou-se menor, cursaram faculdades privadas (algumas fora da cidade de São Paulo), tiveram mais dificuldade em citar nome de livros lidos ou de artistas preferidos, dificilmente acessam a Internet, nunca viajaram para fora do Brasil e para dois deles, a visita ao Museu Lasar Segall foi a primeira visita a um museu. Assim, um aspecto a ser observado diz respeito a relevância que a instituição formadora (as públicas, com maior renome acadêmico e as privadas, geralmente com menor prestígio na área educacional) possui na constituição de um hábito de freqüência a espaços culturais; entretanto, é fundamental considerar a importância que a ação familiar e, conseqüentemente, os hábitos culturais na infância têm sobre a possibilidade dos indivíduos acessarem os bens culturais quando mais velhos, e o modo como isso será feito. Nas entrevistas realizadas com dois professores do primeiro grupo, foi possível apreender algumas estratégias desenvolvidas por famílias que, embora fracamente dotadas de capital escolar ou capital cultural, contribuem para apropriação dos objetos culturais por parte de seus filhos, seja valorizando a escolarização e o papel da escola, seja servindo como intermediário entre a cultura considerada legítima e as crianças

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Lazar, Mihai Bogdan Chante Jean-Pierre Raynaud Christophe. "Etude du dopage par implantation ionique d'aluminium dans le carbure de silicium pour la réalisation de composants de puissance." [S.l.] : [s.n.], 2002. http://csidoc.insa-lyon.fr/these/2001/lazar/index.html.

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Arrigoni, Michel. "ETUDE DE L'INFLUENCE DES RUGOSITES D'INTERFACE, DE POROSITES ET DE L'EPAISSEUR D'ECHANTILLON SUR LA PROPAGATION DES CHOCS LASER DANS DES SYSTEMES REVETUS. APPLICATION AU PROCEDE LASAT (LASER ADHÉRENCE TEST)." Phd thesis, Université de Poitiers, 2004. http://tel.archives-ouvertes.fr/tel-00376349.

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Arrigoni, Michel. "Étude de l'influence des rugosités d'interface, de porosités et de l'épaisseur d'échantillon sur la propagation des chocs laser dans des systèmes revêtus : application au procédé LASAT (LASer Adhérence Test)." Poitiers, 2004. http://www.theses.fr/2004POIT2328.

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Un nombre croissant d'applications font intervenir des systèmes revêtus. Ainsi, le développement des techniques de dépôt et des essais d'adhérence prennent de l'ampleur. Le projet LASAT (LASer Adhérence Test) propose un essai sans contact basé sur le choc laser, automatisable pouvant être intégré dans un environnement industriel. Cette technique repose sur la génération de traction à l'interface suite à la propagation d'un choc dans une cible substrat/dépôt. Afin d'intégrer la réalité industrielle de fabrication des échantillons, cette étude montre l'influence de la rugosité d'interface et de porosités sur la propagation des chocs au sein des échantillons et la mise en traction de l'interface. Le choc laser limitant le test à de faibles épaisseurs d'échantillons (<1mm), des solutions nouvelles sont étudiées pour étendre le test des systèmes plus épais. L'impact de feuilles accélérées par laser permet de réaliser le test sur des systèmes de quelques millimètres d’épaisseur An increasing number of applications are interested in using coated systems. Therefore, coatings deposition methods and adherence testing techniques are more and more required by the industry. The LASAT process (LAser Shock Adherence Test) consists in a no contact, automatic debonding test that can be implemented in an industrial background. This technique lies on shock wave propagation and consecutive traction at the interface of multi-layered targets. In order to account for realistic industrial systems, the effect of interface roughness and the porosity of the coating upon traction yielded at the interface is investigated. Laser shocks use reduces the application of the debonding test to systems within the millimetric range. New solutions to push up this limit have been studied. The ability of laser driven fliers impact to realize the debonding test for a few millimeters thickness systems has been evidenced

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Barradas, Sophie. "Etude, à l'aide du choc laser, des mécanismes d'adhérence aux interfaces cuivre/aluminium et cuivre/cuivre obtenues par projection thermique." Phd thesis, École Nationale Supérieure des Mines de Paris, 2004. http://tel.archives-ouvertes.fr/tel-00273506.

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La réalisation de revêtements projetés de haute qualité passe par une bonne cohésion du dépôt et une adhérence élevée des revêtements sur leur substrat. Du fait de leur mode d'élaboration, les microstructures des interfaces dépôt/substrat et particule/particule obtenues par projection thermique sont complexes et les propriétés en dépendant hétérogènes. Afin d'optimiser l'adhérence des revêtements, il est nécessaire d'établir des relations entre microstructure et résistance de ces interfaces. C'est l'objet de cette étude. Le système modèle cuivre projeté sur aluminium a été retenu non seulement pour son fort potentiel industriel mais également pour la grande réactivité métallurgique du couple (Al, Cu). Des interfaces présentant des propriétés métallurgiques variées ont ainsi pu être obtenues, en jouant sur les procédés et conditions de projection. Ces interfaces ont été analysées à des échelles fines. Des caractérisations quantitatives des propriétés métallurgiques et morphologiques de ces interfaces ont aussi été réalisées. Un essai d'adhérence original, utilisant le phénomène de choc laser, a été développé pour déterminer l'adhérence de revêtements épais (quelques centaines de microns) correspondant à ces interfaces. L'essai LASAT (pour LASer Adhérence Test) s'est avéré particulièrement sensible aux propriétés des interfaces et approprié à leur étude locale. L'association des analyses fines et quantitatives des interfaces avec l'évaluation de leur résistance par l'essai de choc laser a permis d'identifier les principaux mécanismes d'adhérence responsables de la bonne tenue des revêtements de Cu sur Al et/ou des particules de Cu sur celles déjà déposées, dans le cas de projections plasma, HVOF et cold spray. L'influence de la propreté et de la morphologie des interfaces sur l'adhérence des dépôts projetés a été, en particulier, étudiée. Enfin, des outils de simulation ont permis de reproduire les phénomènes intervenant aux interfaces obtenues par projection thermique et ainsi de préciser les modes de formation des liaisons interfaciales.

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Rogers, Kevin Shaun. "Laser desorption/laser ionization mass spectroscopy." Thesis, University of Salford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357037.

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Wu, Jianfeng. "Thulium Doped Microsphere Laser and Fiber Laser." Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1369%5F1%5Fm.pdf&type=application/pdf.

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Baudin, Lucie. "Structuration de surface par laser dans l’environnement des accélérateurs de particules : relation entre topographie superficielle, adhésion des particules et compatibilité aux applications ultravide." Thesis, Université Paris sciences et lettres, 2020. http://www.theses.fr/2020UPSLM052.

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La structuration laser des surfaces a été développée au CERN pour le traitement des parois internes de l’enceinte à vide où circulent les protons. Le balayage de la surface par le faisceau laser creuse des sillons en ablatant le cuivre dont une partie est redéposée sur la surface sous la forme d’agrégats de particules. Cette rugosité à deux échelles absorbe efficacement les électrons, mais l’impact sur les autres fonctionnalités de la machine doit être vérifié. Pendant son opération, la surface est soumise à des forces électromagnétiques et des variations de température qui pourraient l’endommager. Deux méthodes d’extraction de particules, chocs laser et centrifugation, ont été déployées pour tester l’adhésion des particules en laboratoire. Bien qu’il ait été constaté que la surface préserverait ses propriétés, le détachement de particules, suite aux sollicitations mécaniques ou au traitement in-situ, est une question ouverte qui devrait motiver le choix de paramètres de traitement alternatifs ou d’une stratégie de nettoyage Laser-assisted surface structuration was developed at CERN for the treatment of the inside wall of the vacuum system. Grooves were created by material ablation while the laser scanned the surface. A part of this material was redeposed as particle aggregates. This two-scale rugosity efficiently trap electrons. The effects on other surface functionalities had to be assessed. During its operation, the surface is submitted to electro-mechanical forces and cooling cycles which might deteriorate its performances. Two extraction techniques have been developed - laser-shocks and centrifugation - to assess particle adhesion. Although the surface properties are not detrimentally degraded, massive particle detachment during operation or during the treatment itself is an issue that should motivate the choice of alternative treatment parameters or of a cleaning strategy

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Löser, Markus. "Diode-Pumped High-Energy Laser Amplifiers for Ultrashort Laser Pulses The PENELOPE Laser System." Helmholtz-Zentrum Dresden - Rossendorf, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-232322.

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The ultrashort chirped pulse amplification (CPA) laser technology opens the path to high intensities of 10^21 W/cm² and above in the laser focus. Such intensities allow laser-matter interaction in the relativistic intensity regime. Direct diode-pumped ultrashort solid-state lasers combine high-energy, high-power and efficient amplification together, which are the main advantages compared to flashlamp-pumped high-energy laser systems based on titanium-doped sapphire. Development within recent years in the field of laser diodes makes them more and more attractive in terms of total costs, compactness and lifetime. This work is dedicated to the Petawatt, ENergy-Efficient Laser for Optical Plasma Experiments (PENELOPE) project, a fully and directly diode-pumped laser system under development at the Helmholtz–Zentrum Dresden – Rossendorf (HZDR), aiming at 150 fs long pulses with energies of up to 150 J at repetition rates of up to 1 Hz. The focus of this thesis lies on the spectral and width manipulation of the front-end amplifiers, trivalent ytterbium-doped calcium fluoride (Yb3+:CaF2) as gain material as well as the pump source for the final two main amplifiers of the PENELOPE laser system. Here, all crucial design parameters were investigated and a further successful scaling of the laser system to its target values was shown. Gain narrowing is the dominant process for spectral bandwidth reduction during the amplification at the high-gain front-end amplifiers. Active or passive spectral gain control filter can be used to counteract this effect. A pulse duration of 121 fs was achieved by using a passive spectral attenuation inside a regenerative amplifier, which corresponds to an improvement by a factor of almost 2 compared to the start of this work. A proof-of-concept experiment showed the capability of the pre-shaping approach. A spectral bandwidth of 20nm was transferred through the first multipass amplifier at a total gain of 300. Finally, the predicted output spectrum calculated by a numerical model of the final amplifier stages was in a good agreement with the experimental results. The spectroscopic properties of Yb3+:CaF2 matches the constraints for ultrashort laser pulse amplification and direct diode pumping. Pumping close to the zero phonon line at 976nm is preferable compared to 940nm as the pump intensity saturation is significantly lower. A broad gain cross section of up to 50nm is achievable for typical inversion levels. Furthermore, moderate cryogenic temperatures (above 200K) can be used to improve the amplification performance of Yb3+:CaF2. The optical quality of the doped crystals currently available on the market is sufficient to build amplifiers in the hundred joule range. The designed pump source for the last two amplifiers is based on two side pumping in a double pass configuration. However, this concept requires the necessity of brightness conservation for the installed laser diodes. Therefore, a fully relay imaging setup (4f optical system) along the optical path from the stacks to the gain material including the global beam homogenization was developed in a novel approach. Beside these major parts the amplifier architecture and relay imaging telescopes as well as temporal intensity contrast (TIC) was investigated. An all reflective concept for the relay imaging amplifiers and telescopes was selected, which results in several advantages especially an achromatic behavior and low B-Integral. The TIC of the front-end was improved, as the pre- and postpulses due to the plane-parallel active-mirror was eliminated by wedging the gain medium.

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Löser, Markus. "Diode-Pumped High-Energy Laser Amplifiers for Ultrashort Laser Pulses The PENELOPE Laser System." Doctoral thesis, Helmholtz-Zentrum Dresden - Rossendorf, 2017. https://tud.qucosa.de/id/qucosa%3A30755.

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Carns, Jennifer. "Semiconductor Optical Amplifier as a Phase Modulator for Short-Pulse Synthetic Aperture Ladar and Vibrometry." University of Dayton / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1335278035.

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Kiehn, G. P. "XUV laser amplication in recombining laser produced plasmas." Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379973.

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Romagnani, L. "Laser-plasma investigations employing laser-driven proton probes." Thesis, Queen's University Belfast, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426587.

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Qiu, Wenqian. "Modelling of laser-plasma in laser microspectral analysis." Thesis, University of Aberdeen, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386302.

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The behaviour of the laser-produced plasma plume plays an important part in understanding and controlling the laser material processing involved in laser microspectral analysis. A multi-dimensional time-dependent model has been developed to simulate the transient material behaviour after an intense laser pulse irradiating a target surface. In this model, the heating and phase transition of the target material have been studied using the heat transfer theory, and the formation and evolution of the plasma plume were modelled by the Euler equations of fluid dynamics, which include the conservation of mass, momentum and energy. The energy absorption in the plasma by inverse Bremsstrahlung was considered, and the interface between the plasma plume and surrounding air was tracked by a fractional volume method. Moreover, the temperature-dependent optical and thermal properties of the target material and the spatial and temporal characteristics of the laser irradiance have been taken into account. The equations in the model were solved numerically by means of a finite-volume based time marching algorithm. Finally, experiments were carried out to support this model. This model is capable of predicting the onset of melting and evaporation, the crater development, the transient temperature distribution in the target, spatial and temporal behaviour of the plasma flow and, finally, the formation and propagation of a shock wave in the surrounding air. The transient spatial distributions of the plasma parameters, i.e., the temperature, density, pressure and velocity are presented in two-dimensional colour contour diagrams as well as the transient temperature profiles in the target. All these outcomes enable the optimisation of the process of laser-material interaction and provide valuable information in interpretation of the recorded spectrum and the consequent quantitative analysis of target composition in laser microspectral analysis.

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Hamidi, Serajeddin. "Filamentation of laser light in laser-produced plasmas." Thesis, University of Essex, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.279422.

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Lee, Junho. "Semiconductor diode laser with saturable absorber (S-laser)." [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0004277.

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Komashko, Aleksey Mikhaylovich. "Laser-material interaction of powerful ultrashort laser pulses /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2003. http://uclibs.org/PID/11984.

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Chung, S. H. "Gunn laser." Thesis, University of Essex, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.421149.

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Vigil, Ricardo. "Laser accelerator." Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/44024.

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Approved for public release; distribution is unlimited In 1979,W. B. Colson and S. K. Ride proposed a new kind of electron accelerator using a uniform magnetic field in combination with a circularly-polarized laser field. A key concept is to couple the oscillating electric field to the electron’s motion so that acceleration is sustained. This dissertation investigates the performance of the proposed laser accelerator using modern high powered lasers and mag-netic fields that are significantly improved over the values in the original analysis. The relativistic equations of motion for the electron are solved analytically and for the first time numerically for more general results than previously reported. Realistic beam effects are investigated to determine the constraints on initial electron energy, injection angle, and phase to achieve optimal performance. This analysis indicates that the selection of an electron’s initial conditions are not as stringent as previously thought. Simulations indicate a university scale system can achieve electron energy gain of over one GeV in a meter.

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Lee, Soo-Keun. "Laser photocatalysts." Thesis, Robert Gordon University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.344019.

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Mendiola, David Mario. "Laser guitar." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/45322.

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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008. Includes bibliographical references (p. 24). Music is constantly evolving, both in the culture and musical theory that dictates its structure, and the technology used to create the actual sound. This thesis explores a direction for development of one of the most proven instruments in musical brainstorming as well as live performance; the guitar. The form and feel has stayed nearly the same since its conception and it is a solid foundation with which to integrate modern technology. The design is to replace the strings with beams of laser that run through a line of beam splitters at each fret, each of which sends a beam onto a photoresistor. By blocking the beam at different frets, the current through the resistors uniquely determines what fret is pressed. The motivation for this development is twofold; firstly, the aesthetic appeal of a brilliantly lit guitar could make this a popular instrument for live shows, and, secondly, the lasers would be more versatile than strings, allowing the player to program frets to be any note. By doing this, the writing process could be enhanced with more options to experiment with, and the performance of difficult compositions could be simplified. This paper begins the design of the instrument and proposes solutions for some possible complications in creating it. by David Mario Mendiola. S.B.

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Monson, Paul J. E. "Laser hardfacing." Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/47187.

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Kashkol, Tania. "Hederns lagar." Thesis, Enskilda Högskolan Stockholm, Högskolan för mänskliga rättigheter och demokrati, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ths:diva-1320.

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In 2020, it has been confirmed that approximately 240,000 people in Sweden are exposed to some kind of honor-related violence that can, in the worst case, lead to another persons death. The report claims that the dark figure is much higher than what the existing figures show. In this essay there will be a couple of cases that will be presented. The cases has a huge part of the Swedish legal system and attitude change towards honor-related violence and honor killing. The reasoning around the cases will be presented in order for the reader to gain knowledge and concretization of the Swedish state's approach to these cases.

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Neto, Jonas Jakutis. "Lasers de Nd:YLF de baixo ganho operando na transição de quase-três níveis e em lasers Raman." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-29042013-100734/.

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Lasers operando nas regiões espectrais do azul e do amarelo-laranja foram recentemente requisitados pelo mercado de aplicações quer para melhorar as tecnologias já conhecidas ou para possibilitar a criação de novas. Isso é devido às propriedades destas regiões espectrais, com o azul trazendo características tais como fótons de alta energia e feixes limitados por difração menores, enquanto a faixa do amarelo-laranja é ainda uma região espectral difícil de se atingir e não foi totalmente acessada ou nem mesmo acessada por fontes de luz laser eficientes. Aplicações dos lasers azuis são encontradas em tecnologias de alta densidade de armazenamento, displays a laser, sistemas LIDAR, pinças ópticas e uma longa série de aplicações que exigem alta precisão. Os lasers amarelo-laranja também têm aplicações importantes, destacando-se aplicações em cirurgia oftalmológica a laser, em displays de cores reais e como estrela guia (excitando linhas de sódio na atmosfera). A investigação de lasers de quase três níveis e laser Raman de Nd:YLF foi realizada neste trabalho. A finalidade é de propor fontes laser de alta potência e eficientes emitindo no azul e no amarelo para suprir as aplicações. Eficiência e potências de saída da ordem de Watt foram demonstradas para um laser de Nd:YLF emitindo em 908 nm assim como no segundo harmônico em 454 nm. Além disso, lasers Raman de Nd:YLF/BaWO4 e Nd:YLF/KGW foram demonstrados atingindo alguns Watts de potência de saída em regime quasi-CW e CW, com boas qualidades de feixe (M2 2) e em oito comprimentos de onda diferentes: 1147 nm, 1163 nm, 1167 nm , 549 nm, 552 nm, 573 nm, 581 nm e nm 583. Por fim, uma luminescência azul originada em alguns cristais Raman, durante a oscilação Stokes, teve sua origem e seus efeitos colaterais para lasers (perdas e calor adicionais) minuciosamente caracterizados. Lasers operating in the blue and yellow-orange spectral regions are sought after by the applications market either to improve well known technologies or to enable new ones. Blue lasers bring features such as high energy photons and smaller diffraction limited beams, while the yellow-orange range is a hard to reach spectral region where there is a considerable shortage of efficient laser light sources. Applications of the blue lasers are found in high density storage technologies, laser displays, LIDAR systems, optical tweezers and a long range of high precision demanding applications. The yellow-orange lasers also have important applications, with highlights in ophthalmologic laser surgery (photocoagulation), in true color displays and as a guide star (exciting sodium lines in the atmosphere). The investigation of Nd:YLF quasi-three level lasers and Nd:YLF Raman lasers was further studied in this work in order to provide high power and efficient blue and yellow lasers sources. Demonstrations of efficient and multi-Watt operation of a 908 nm laser and its respective second harmonic laser at 454 nm are described. Also, Nd:YLF/BaWO4 and Nd:YLF/KGW Raman lasers were demonstrated reaching Watt levels in quasi-CW and CW regime with very good beam qualities (M2 2) at eight different wavelengths: 1147 nm, 1163 nm, 1167 nm, 549 nm, 552 nm, 573 nm, 581 nm and 583 nm. Finally, a blue luminescence originating in some Raman crystals, during Stokes oscillation, has been studied in considerable detail. Its origin and consequences for laser operation (extra loss and heat load) have been identified.

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You, Yan. "Pulsed Laser Injected Enhancement Cavity for Laser-electron Interaction." Phd thesis, Université Paris Sud - Paris XI, 2014. http://tel.archives-ouvertes.fr/tel-01011958.

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X-ray diﬀraction and scattering, X-ray spectroscopy, and X-ray crystallography are widely used in the life sciences, material science, and medical diagnosis. High-quality and high-brightness X-rays are a strong requirement to improve applications. Inverse Compton scattering (ICS) X-ray source has attracted great interests worldwide lately. To significantly enhance the average X-ray photon flux, a compact electron storage-ring combined with a high finesse optical enhancement cavity (OEC) can be utilized. In such a system, the collision rate between the electron beam and the laser pulse is greatly increased to the MHz range, enabling a photon flux up to 10¹³ph/s.In the first chapter, I describe the motivation behind the development of OEC based on ICS X-ray source. The characteristics of this kind of X-ray source are summarized, compared to those of the conventional low-repetition-rate Terawatt laser system based on ICS X-ray source. The latest progress and research status of OEC based on ICS X-ray source are presented. Pulsed-laser injected high-finesse OEC stacking theory and properties are discussed in Chapter 2. Not only does the OEC based on ICS X-ray source require the laser pulse repetition rate to be matched to the free spectral range (FSR) of the cavity, where both also have to match the electron storage-ring circulation frequency. In addition, we have to match the phase shift of the laser repetition rate to the phase offset introduced by the dispersion of the cavity mirrors, since our cavity finesse design value is quite high. The stacking theory is analyzed in the frequency domain. Cavity properties, including cavity mirror dispersion, finesse, and FSR, are discussed in detail. A laser frequency comb and OEC coupling is analyzed also. The laser source development is presented in Chapter 3. We constructed a mode-locked fiber laser based on nonlinear polarization rotation. The locking model, locking techniques, and the theory, simulations and experimental tests of tilt locking (TL) in the pulsed laser injected high-finesse OEC are discussed in Chapter 4. We succeeded in locking a pulsed laser to a high-finesse cavity with the TL technique. The experimental results show that the TL and the Pound-Drever-Hall techniques have the same performance: stable locking, high sensitivity, and the same power coupling rate for picosecond laser pulse case, while the test results for full spectrum TL locking show that it is uneasy to align the split-photodiode to the beam waist.Based on the above experimental study and tests, we design the OEC system for Tsinghua University X-ray project in Chapter 5. The expected X-ray flux is 10¹º to 10¹³ ph/s. We detail every subsystem requirement.

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Clipston, Nigel L. "Laser desorption/laser ionization Time-of-Flight Mass Spectrometry." Thesis, University of Salford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360476.

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Purcell, S. M. "Laser induced molecular motion in strong nonresonant laser fields." Thesis, University College London (University of London), 2010. http://discovery.ucl.ac.uk/19225/.

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The optical dipole force from a singe focussed laser beam was used to study the role of laser-induced molecular alignment on the centre-of-mass motion of carbon disulphide molecules in a molecular beam. The translational, rotational and vibrational temperatures of the carbon disulphide molecules were measured to be 3.4\pm0.2 K, 35\pm10 K and 250\pm14 K respectively. The velocity of the beam was measured to be 542\pm22 m s ^{-1}. Time-of-flight mass spectroscopy was used to measure the acceleration and deceleration of the molecules. Maximum velocity changes of 7.5 m s ^{-1} and 10 m s ^{-1} were recorded for linearly and circularly polarised light respectively. These results showed that the dipole force, \digamma \alpha \bigtriangledown [\alpha_e_f_f(I)I(r)], where \alpha_e_f_f is the effective polarisability and determined through laser-induced alignment, can be modified by changing the laser polarisation. For linearly and circularly polarised light, a 12% difference in effective polarisability was measured to produce a 20% difference in dipole force. The dipole force from a single focussed laser beam produces a molecular optical lens and the downstream density of the molecular focus was probed by measuring the ion signal for both laser polarisations. The focal lengths for linearly and circularly polarised light were found to be separated by \approx 100 \mu m. By altering the laser polarisation from linearly through elliptically to circularly polarised light, the focal length of the molecular optical lens could be smoothly altered over the \approx 100 \mu m focal range. The role of the effective polarisability of each rotational state was also studied numerically. Separate rotational states were found to significantly alter the focal properties of a molecular optical lens. In carbon disulphide, higher rotational states (J > 10), exhibit less molecular alignment and when occupied, the focal length of the molecular optical lens for these states was increased by 60 % compared to the ground state.

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Dale, Michael John. "Laser desorption laser photoionisation time-of-flight mass spectrometry." Thesis, University of Edinburgh, 1994. http://hdl.handle.net/1842/13547.

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The work described in this thesis is concerned with the development and application of laser desorption laser photoionisation time-of-flight mass spectrometry (L2TOFMS). This technique has been used to enable photoionisation mass spectra of a very wide variety of involatile and thermally labile molecules to be recorded. The instrument used for this work is described along with an overview of the fundamental principles behind this methodology. A number of specific classes of molecules have been studied using the L2TOFMS. These include polyaromatic hydrocarbons, porphyrins, dyestuffs and a variety of analytically important staining agents. The advantages of this approach for analysing complex mixtures, which yield relatively simple mass spectra, have been demonstrated for both environmental systems and commercially important mixtures. It has also been shown that L2TOFMS can be used for the direct interrogation of target systems adsorbed onto organic substrates. L2TOFMS has been used to probe the photophysics of both porphyrin molecules and a series of azo dyes. Ionising wavelength dependent fragmentation was observed for a number of metallotetraphenylprophyrins and metallo- octaethylporphyrins. Using 193 nm laser photoionisation, molecular dissociation, involving loss of the macrocycle side groups, was shown to be similar to that obtained by electron impact ionisation. Whereas, at 266 nm, fragmentation via a neutral intermediate state, resulting in the loss of the metal from the macrocycle, competes with further photon absorption. Characteristic azo-bond photoreductive cleavage has been observed for azo molecules when using 266 nm laser photoionisation. This behaviour is linked to the cis-trans photoiosomerisation of the azo bond.

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Ghneim, Said Nimr 1953. "Laser pulse amplification through a laser-cooled active plasma." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276868.

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Recent advances in experimental laser cooling have shown the possibility of stopping an atomic beam using the light pressure force of a counter-propagating laser wave. As an application to laser cooling, it is proposed to build a single frequency cesium laser that has a narrow linewidth. Laser cooling techniques are used to cool an atomic beam of cesium to an average velocity of 5 m/s, corresponding to a temperature of 0.2°K. Expressions of the basic forces that a laser wave exerts on atoms are derived according to a semi-classical approach. The experimental problems and methods of avoiding these problems are treated in detail. A computer Monte-Carlo simulation is used to discuss the feasibility of building the proposed laser. This simulation was done for an ensemble of 10,000 atoms of cesium, and it included the effects of the gravitational force and the related experimental variables. The possibility of building single frequency lasers that use a cooled medium of noble gases, and many other applications of laser cooling are briefly discussed at the end of this work.

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Chauzat, Corinne. "Études expérimentales de lasers microchips à émission continue mono-fréquence à 553 nm et à 561 nm, de puissance supérieure à 200 mW." Thesis, Rennes 1, 2014. http://www.theses.fr/2014REN1S007.

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Le remplacement des lasers à colorant émettant dans la gamme 550-570 nm, à l'aide de lasers solides, représente un véritable enjeu industriel. Les applications sont multiples tant dans le domaine de la recherche biomédicale que dans celui de la métrologie. Quelques solutions ont été développées à 561 nm et à 553 nm. Néanmoins, elles ne permettent pas de fournir des lasers intégrables parfaitement mono-fréquences émettant en continu un faisceau gaussien, d'une puissance supérieure ou égale à 200 mW. Dans ces travaux, nous proposons une étude théorique et expérimentale de cavités lasers solides monolithiques à base de Nd:YAG pompé par diode, doublé en fréquence en intra-cavité, à l'aide d'un cristal non-linéaire de KTP. Ces cavités, constituées de plusieurs cristaux, sont contactées par adhérence moléculaire. Elles ne contiennent aucune optique de mise en forme des faisceaux et présentent la particularité de comporter un double filtre de Lyot. Nous présentons les résultats obtenus avec des cavités émettant à 561 nm pour des puissances supérieures ou égales à 300 mW. Puis, après une étude statistique et une analyse des résultats de test de ces cavités à long terme (> 6000 heures), nous discutons des problèmes éventuels de fiabilité et nous suggérons des axes d'amélioration. Ayant réussi à faire osciller, pour la première fois, la raie à 1106 nm du Nd:YAG, nous montrons ensuite la faisabilité d'un laser compact mono-fréquence continu à 553 nm, émettant une puissance de 200 mW à 500 mW avec un rendement de conversion pompe/laser visible de l'ordre de 19 %. Pour conclure, nous montrons qu'il est possible, dans des cavités de ce type, de faire osciller des raies Raman issues des raies fondamentales et de les doubler en fréquence en intra-cavité. Nous ouvrons ainsi la porte à toute une famille de lasers solides émettant dans la gamme 540-600 nm Replacement of dye lasers emitting in the range 550-570 nm, using solid state lasers, is a real industrial issue. There are many applications both in the field of biomedical research than in metrology. Some solutions have been developed for 561 nm and 553 nm. However, they do not provide fully integrated lasers emitting single-frequency continuous Gaussian beam with a power equal or up to 200 mW. In this work, we propose a theoretical and experimental study of solid monolithic cavity lasers based on Nd:YAG diode-pumped, frequency-doubled intra-cavity, using a non-linear crystal of KTP. These cavities, consisting of several crystals, are contacted by molecular adhesion. They contain no optical layout of the beams and they have the particularity of including a double Lyot filter. We present the results obtained with those cavities emitting at 561 nm for powers greater than 300 mW. Then, after a statistical study and analysis of test results of these cavities in the long term (> 6000 hours), we discuss about the potential problems of reliability and we suggest areas for improvement. For the first time, we show that the line at 1106 nm of the Nd: YAG can oscillate in this type of cavity. Then we demonstrate the feasibility of a compact single-frequency laser at 553 nm continuously, emitting a power of 200 mW to 500 mW with a conversion efficiency of pump / visible laser of about 19%. Finally, we show that it is possible, in cavities of this type, to oscillate the Raman lines from the lines of the fundamental and doubled frequency in intra-cavity. We open the door to a whole family of solid state lasers emitting in the range of 540-600 nm

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Bégué, Geoffrey. "Etude de l'adhérence de barrière thermique EB-PVD par choc laser (LASAT) pour le développement d'un contrôle non-destructif sur aube de turbine aéronautique." Thesis, Paris, ENMP, 2015. http://www.theses.fr/2015ENMP0093.

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L'évaluation de la résistance interfaciale des systèmes barrière thermique EB-PVD est primordiale afin de pouvoir contrôler la production d'aubes de turbine revêtues et d'améliorer la compréhension des phénomènes d'écaillage de la céramique qui se produisent en fonctionnement. L'essai d'adhésion par choc laser LASAT qui s'appuie sur la propagation bidimensionnelle des ondes de choc (le phénomène LASAT-2D) consiste à mesurer le diamètre de fissure interfaciale pour différents tirs effectués à densité de puissance laser croissante. L'application de l'essai LASAT sur une pièce industrielle nécessite d'effectuer le choc du côté revêtu de céramique. Un adhésif vinylique protecteur ainsi qu'un milieu de confinement par adhésif transparent sont utilisés afin de générer un choc en surface de la céramique. La propagation de l'onde de choc est étudiée à travers des expériences spécifiques ainsi qu'une simulation numérique. La fissuration de l'interface est révélée par la présence d'une tache qui est mesurée par observation optique du dessus de la céramique. La reproductibilité de l'essai LASAT appliqué côté céramique est établie. Dans l'optique de valider un protocole de contrôle non destructif, le cyclage thermique est utilisé pour évaluer la nocivité d'une zone choquée présentant ou non des fissures. La présence de fissures à l'interface entre l'alumine et la zircone ne diminue pas la durée de vie à écaillage d'aubes de turbines lors du cyclage thermique. La tenue mécanique initiale de la céramique est comparée de manière qualitative et quantitative pour différents échantillons et qualitativement pour plusieurs aubes de turbine. L'évolution de la résistance interfaciale en fonction du cyclage thermique est étudiée. On démontre également sur plusieurs échantillons une corrélation entre l'adhérence initiale mesurée par LASAT et la durée de vie à écaillage par cyclage thermique The assessment of the interface strength of EB-PVD thermal barrier coating (TBC) is a key issue to control the production and better understand the ceramic spallation that will occur during life duration of coated turbine blades. The Laser Shock Adhesion Test (LASAT) involving bi-dimensional shock wave propagation, namely the LASAT-2D, consists in measuring the interfacial crack diameter when implementing a set of laser shocks with increased laser power densities. Applying the LASAT onto an industrial blade requires implementing the laser shock onto the ceramic side. A protective vinylic adhesive tape and a confinement by transparent adhesive tape are used to generate the shock on the ceramic. Shock wave propagation is studied through specific experiments and a numerical simulation. The interfacial crack is revealed by the presence of a spot that could be measured on a top-view optical image of the ceramic. Reproductibility of the LASAT applied on the coated side of the TBC is thereby established. Harmfulness of a loaded area with and without cracks is investigated thanks to thermal cycling in order to validate a non-destructive protocol. The presence of cracks at the interface between alumina and zirconia does not reduce the life duration of coated turbine blades in thermal cycling. Initial adhesion strength is compared both qualitatively and quantitatively for different samples and qualitatively for some turbine blades. Evolution of the interface strength with thermal cycling is presented. A correlation between initial adhesion and time of spallation of the ceramic is demonstrated on different samples

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Choi, Ji Yeon. "Ecriture par Laser de fonctionnalités optiques : éléments diffractifs et ONL." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2010. http://tel.archives-ouvertes.fr/tel-00583861.

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A la suite de la première démonstration de l'écriture de guide d'onde au sein de verres en 1996 par laser femtoseconde, l'écriture direct par Laser Femtoseconde (Femtoseconde Direct Laser Writing - FLDW) est apparu comme une technique souple pour la fabrication de structure photonique en trois dimensions au sein de matériaux pour l'optique. La thèse a porté sur l'inscription par laser femtoseconde de fonctionnalités optiques au sein de verres. Des éléments diffractifs par modification de l'indice de réfraction et des structures présentant des propriétés de luminescence ou d'optique non linéaire d'ordre deux ont pu être obtenus au sein de matériaux vitreux et étudiés.

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Sadeghian, Zahra. "Laser sintering of hydroxyapatite by laser-wise slurry deposition (LSD)." [S.l. : s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=974414913.

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