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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Design e tecnologia: manufatura aditiva por sinterização de poliestireno em equipamento de gravação e corte a laser / Design e technology: additive manufacturing by polystyrene sintering using a laser cutting and engraving machine

Ribeiro, Thiago Rafael Rodrigues January 2018 (has links)
A sinterização a laser (SL), uma das tecnologias de manufatura aditiva (MA), se mostra de grande interesse devido a uma série de características, mas, principalmente, devido a sua capacidade de processar uma ampla gama de materiais em pó, a qual amplia possibilidades de pesquisa e desenvolvimento no campo do Design. Neste trabalho, sob o prisma da MA, tem-se por objetivo realizar a sinterização a laser em um equipamento de gravação e corte a laser convencional, sem pré-aquecimento do material. No desenvolvimento do estudo, foi utilizado um equipamento galvanométrico a laser para a realização de experimentos de sinterização de poliestireno em pó (PS 200). Os ensaios de caracterização desse material polimérico amorfo, constataram o diâmetro médio dos grãos de 54,3 μm em formato irregular. Para viabilizar o processo proposto, investigaram-se os parâmetros de processo para a SL, valendo-se de um dispositivo de controle da altura da mesa de trabalho. A melhor amostra (geometria circular) foi construída com potência 20 W, velocidade de varredura de 200 m/min e distância entre linhas de varredura do feixe laser de 0,1 mm. Esse último parâmetro, é relacionado ao diâmetro do foco do feixe laser, o qual foi estimado pelos ensaios em 0,3 mm. Com isso, foi calculada a densidade de energia transferida para o material, conhecida como Número de Andrew (An), em 0,06 J/mm² Análises visuais, macroscópicas e microscópicas, antes e depois da sinterização de uma camada (2D) e de camadas empilhadas (3D), além de sua digitalização tridimensional, foram realizadas. As amostras apresentaram deformação no plano x-y (elipticidade), no eixo z (empenamento) e grande porosidade. Nos ensaios de empilhamento de camadas foi determinada, para os parâmetros utilizados, a espessura de camada de 0,15 mm. Posteriormente, foi construído um modelo 3D com 100 camadas, o qual apresentou um acabamento liso na maior parte de sua lateral, porém, foram observadas estrias verticais ao longo da sua altura, as quais foram consideradas como característica do processo (devido à inércia dos espelhos galvanométricos). Por fim, esses parâmetros foram validados em um ensaio valendo-se de uma forma orgânica (face humana) em escala 1:4. O fator crítico foi o empenamento, o qual prejudica a distribuição de novas camadas de pó, mas pôde ser contornado com espessuras de camada de alturas superiores a esse empenamento. Assim, considera-se que para a viabilização prática do processo de sinterização proposto, em equipamentos de corte e gravação a laser convencionais, torna-se importante o desenvolvimento de um dispositivo de distribuição de pó automatizado, o qual permitiria a construção de modelos 3D de maior tamanho e complexidade. / Laser sintering (SL), one of the additive manufacturing (MA) technologies, is of great interest due to a number of characteristics, but mainly due to its ability to process a wide range of powder materials, which offers possibilities for research and development in the Design’s field. In this work, under the prism of the MA, the goal is to perform laser sintering in a conventional laser engraving and cutting equipment, without preheating the material. In the development of the study, a galvanometric laser equipment was used to perform powder polystyrene (PS 200) sintering experiments. The characterization tests of this amorphous polymer material showed the average grain diameter of 54.3 μm in irregular shape. In order to make the proposed process feasible, the process parameters for the SL were investigated, using a device to control the height of the workbench. The best sample (circular geometry) was built with 20 W power, laser scan speed of 200 m/min and distance between scanned lines of 0.1 mm. This last parameter is related to the diameter of the laser beam waist, which was estimated by the tests in 0.3 mm Thus, the energy density transferred to the material, known as Andrew's Number (An), was calculated at 0.06 J/mm². Macroscopic and microscopic visual analysis, before and after the sintering of a two-dimensional layer (2D) and of stacked layers (3D), in addition to its 3D scanning, were performed. The samples displayed deformation in the x-y plane (ellipticity), at the z-axis (warpage) and high porosity. In the layer stacking tests, the layer thickness of 0.15 mm was determined for the parameters used. Next, a 3D model with 100 layers was sintered, which presented a smooth finish in most of its lateral, however, vertical streaks were observed along its height, which were considered as characteristic of the process (due to the inertia of the galvanometric mirrors). Finally, these parameters were validated in an assay using an organic form (human face) in a 1: 4 scale. The critical factor was the warpage, which impairs the distribution of new layers of powder, but could be worked around with layer thicknesses of heights higher than this warpage. Thus, it is considered that for the practical feasibility of the proposed sintering process in conventional laser cutting and engraving machine, it is important to develop an automated powder distribution device, which would allow the construction of greater size and complexity 3D models.
122

Imagem gravada: das matrizes de papelão e cola vinil às impressões em encavo / Image engraved: from cardboard matrixes and glue vinyl to chalcography impressions

Deus, Helder Amorim Silva Borges de 07 April 2016 (has links)
Submitted by Jaqueline Silva (jtas29@gmail.com) on 2016-09-13T17:34:46Z No. of bitstreams: 5 Dissertação - Helder Amorim Silva Borges de Deus - 2016 (1).pdf: 16375896 bytes, checksum: fa3e3bb95cf6f30a32a1dd8d1a529846 (MD5) Dissertação - Helder Amorim Silva Borges de Deus - 2016 (2).pdf: 15731290 bytes, checksum: 50295692526e16122da9589638dcfadd (MD5) Dissertação - Helder Amorim Silva Borges de Deus - 2016 (3).pdf: 10294020 bytes, checksum: 7e3b48ef326b52364ef11302dc09586f (MD5) Dissertação - Helder Amorim Silva Borges de Deus - 2016 (4).pdf: 18265933 bytes, checksum: 59523587b394d1e88ff8655f19e1905f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2016-09-13T17:35:05Z (GMT) No. of bitstreams: 5 Dissertação - Helder Amorim Silva Borges de Deus - 2016 (1).pdf: 16375896 bytes, checksum: fa3e3bb95cf6f30a32a1dd8d1a529846 (MD5) Dissertação - Helder Amorim Silva Borges de Deus - 2016 (2).pdf: 15731290 bytes, checksum: 50295692526e16122da9589638dcfadd (MD5) Dissertação - Helder Amorim Silva Borges de Deus - 2016 (3).pdf: 10294020 bytes, checksum: 7e3b48ef326b52364ef11302dc09586f (MD5) Dissertação - Helder Amorim Silva Borges de Deus - 2016 (4).pdf: 18265933 bytes, checksum: 59523587b394d1e88ff8655f19e1905f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-09-13T17:35:05Z (GMT). No. of bitstreams: 5 Dissertação - Helder Amorim Silva Borges de Deus - 2016 (1).pdf: 16375896 bytes, checksum: fa3e3bb95cf6f30a32a1dd8d1a529846 (MD5) Dissertação - Helder Amorim Silva Borges de Deus - 2016 (2).pdf: 15731290 bytes, checksum: 50295692526e16122da9589638dcfadd (MD5) Dissertação - Helder Amorim Silva Borges de Deus - 2016 (3).pdf: 10294020 bytes, checksum: 7e3b48ef326b52364ef11302dc09586f (MD5) Dissertação - Helder Amorim Silva Borges de Deus - 2016 (4).pdf: 18265933 bytes, checksum: 59523587b394d1e88ff8655f19e1905f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-04-07 / The research entitled Image engraved: from cardboard matrixes and glue vinyl to chalcography impressions proposes a study in two steps. In the first instance, it aims the production of matrixes and engravings, exploring the combination, materiality and the versatility of two materials which are considered alternative when compared to the traditional use of wood for woodcuts, of metal plates for chalcography, of linoleum for linocuts and stones for lithographs: the cardboard and glue vinyl. Then, these matrixes, which emphasized the chalcography’s processes, were presented to one group of visually impaired sharing narratives constructed by dialogues between our interpretations. / A pesquisa intitulada Imagem gravada: das matrizes de papelão e cola vinil às impressões em encavo propõe um estudo em duas etapas. Em um primeiro momento, dedica-se à produção de matrizes e gravuras explorando a combinação, a materialidade e a versatilidade de dois materiais considerados alternativos, quando comparados ao tradicional uso da madeira nas xilogravuras, das chapas de metal nas calcografias, do linóleo nas linóleogravuras e da pedra calcária nas litografias: o papelão e a cola vinil. Em seguida, essas matrizes, que deram ênfase aos processos de impressão em encavo, foram apresentadas a um grupo de deficientes visuais compartilhando narrativas construídas pelos diálogos entre as nossas interpretações.
123

A poética do labirinto: percursos e passagens na gravura

Macedo, Jarbas Gama, Macedo, Jarbas Gama 27 March 2014 (has links)
Submitted by Aline Batista (alinehb.ufpel@gmail.com) on 2016-03-04T12:50:40Z No. of bitstreams: 2 A poética do labirinto.pdf: 15120660 bytes, checksum: 24a57dd0554fa5935f1d1f075fcb6620 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2016-03-04T14:22:29Z (GMT) No. of bitstreams: 2 A poética do labirinto.pdf: 15120660 bytes, checksum: 24a57dd0554fa5935f1d1f075fcb6620 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2016-03-04T14:26:34Z (GMT) No. of bitstreams: 2 A poética do labirinto.pdf: 15120660 bytes, checksum: 24a57dd0554fa5935f1d1f075fcb6620 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-03-04T14:29:48Z (GMT). No. of bitstreams: 2 A poética do labirinto.pdf: 15120660 bytes, checksum: 24a57dd0554fa5935f1d1f075fcb6620 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-03-27 / Sem bolsa / A pesquisa apresentada foi desenvolvida no Mestrado em Artes Visuais da UFPel e teve como ponto de partida minha produção artística, realizada entre 2012 e 2013. Para tanto, foram utilizados procedimentos inerentes ao campo da gravura. Os conceitos percurso e passagem definem o ato de gravar e de imprimir, respectivamente. Destaca-se que esses procedimentos são vistos como um processo cíclico capaz de conectar as imagens. As marcas e sulcos realizados sobre a superfície de pisos vinílicos que compõem as matrizes e as impressões cujas imagens são transferidas de um suporte para outro. Dessa forma, esses procedimentos assumem autonomia. O objeto de estudo da presente investigação refere-se aos deslocamentos e as transformações que ocorrem com a imagem de um trabalho em relação ao seguinte e às interligações entre eles. Também são considerados os entrelaçamentos entre as matrizes e as estampas que se conectam e que constituem uma rede de imagens. A referida rede é compreendida como um labirinto, formada por obras/matrizes, que carregam em suas superfícies imagens labirínticas. Também é considerada a experiência de gravar essas imagens, ou seja, de percorrer esses labirintos. Para refletir sobre essas conexões as leituras de Lucia Leão, contribuíram com o conceito de estética do labirinto e Umberto Eco com o conceito de elenco visual. Esta proposta busca contribuir com novas alternativas para repensar o campo da gravura contemporânea. / The study explored in Mestrado em Artes Visuais UFPel is about my artistic process done in the period of 2012 and 2013. Therefore, procedures inherent engraving field. The concepts of journey and passage define the act of writing and printing, respectively. It is important to highlight that these procedures have been seeing as a cyclical process able to connect images. Marks and ridges made on the surface of vinyl flooring will compose the matrices and prints whose images are transferred from a support for each other. Thus, these procedures assume autonomy. The object of study is about displacements and changes that happen with the image of a work in relation to the following one and the interconnection between them. It is also considered the interdependence between the matrices and the prints, which are linked together and make a network of images .The network is understood as a labyrinth composed by works/matrices that carry on their surfaces labyrinthine images. It is considered the experience of engraving images as well, it means, to travel into the labyrinths. To think about these connections, Lucia Leon readings adds the concept of aesthetics of the labyrinth; and Umberto Eco brings the concept of the visual list. This proposal aims to contribute with new alternatives to reconsider the field of Contemporary engraving.
124

Gravure et hybridation : arts et sciences, imagerie médicale et mythes / Engraving and hybridisation : arts and sciences, medical imagery and myths

Bernard, Florence 15 December 2017 (has links)
Ancrée dans une pratique personnelle de la gravure s’associant à la photographie, la vidéo et l’installation, cette thèse en arts plastiques explore l’hybridation entre arts et sciences. Elle commence par une recherche des spécificités de la gravure pour construire un point de vue singulier sur les œuvres d’artistes travaillant entre arts et sciences quels que soient leurs médiums. La première partie questionne l’hybridation de la gravure et du numérique comme voie d’accès à la contemporanéité définie par Giorgio Agamben comme «en déphasage» avec son temps. Dans une deuxième partie, l’imagerie médicale et la photographie questionnent l’altérité animale. La recherche se poursuit par l’analyse d’œuvres de Nagi Noda, Wanda Wulz et Xavier Lucchesi qui amènent la question de la référence aux mythes dans le travail personnel. Enfin dans une troisième partie, la recherche théorique et le travail plastique achèvent leur hybridation. Les mythes de Méduse, Orphée ou Épiméthée deviennent le point de départ de créations entre arts et sciences où le processus de la gravure actualise les mythes par l’empreinte qu’elle laisse dans les photographies, les vidéos ou les installations qui mettent en scène des images médicales. Notre thèse est que la gravure constitue, à l’image des archées – organismes récemment découverts par les biologistes – une pratique vivante qui se retrouve là où on ne l’attend pas. L’hybridation dans notre pratique artistique rapproche les archées de l’archè, qui signifie proche de l’origine. / Rooted in my personal practice of engraving combined with photography, video and installation art, this plastic arts thesis explores the hybridisation of arts and science; starting with research into the specificities of engraving to then construct a singular point of view on the works of artists whose practice falls between arts and science, whatever the medium. The first part questions the hybridisation of engraving and digital techniques as an access route to a contemporaneity described by Giogio Agamben as “out of phase” with its time. In the second part, medical imagery and photography question animal alterity. Then the research will be furthered through the analysis of works by Nagi Noda, Wanda Wulz, and Xavier Lucchesi which bring us to the matter of references to myths in personal work. Lastly, in a third part, theoretical research and physical art practice complete their hybridisations. The myths of Medusa, Orpheus and Epimetheus become the starting point of works between art and science where the process of engraving actualises the myths by the imprints it leaves in photographs, videos or installations which show medical imagery. Our thesis is that engraving is, like the archaea – recently discovered microorganisms –, a living practise that can sometimes be found where one least expects it. The hybridisation of our practise bring archaea closer to the arche, and thus closer to the origin.
125

L'estampe et ses transferts : gravures françaises et copies allemandes (1650-1750) / Prints and transfers : French engraving and German copies (1650-1750)

Herbert, Flora 15 June 2017 (has links)
Cette thèse de doctorat propose une réflexion sur les phénomènes de copies en matière d’estampe à travers la production d’éditeurs-graveurs allemands de la seconde moitié du XVIIe siècle et de la première moitié du siècle suivant. Parmi les principaux acteurs du monde de la gravure en Allemagne après la fin de la guerre de Trente ans, certains, à commencer par la famille des Küsel à Augsbourg, se sont largement investis dans la réalisation et l’édition de copies gravées. Parmi les modèles utilisés par ces graveurs, l’estampe française du XVIIe siècle tient une place centrale. Remises dans leur contexte historique, technique et artistique, ces copies permettent d’aborder un rapport à la reproduction et diffusion des images différent d’aujourd’hui. Trois niveaux de transferts sont dans ce cadre interrogés. Le premier se réfère à la pratique même du copiste, qui transfère son modèle sur une plaque à graver. Le deuxième niveau de transfert concerne plus spécifiquement les translations qui s’opèrent d’un pays à un autre. Enfin, le troisième interroge la manière dont le désir de s’approprier l’original se reporte sur la copie. Il s’agit ainsi de replacer ces phénomènes de copies dans leurs contextes de production respectifs mais aussi d’étudier ce qu’implique cette pratique, tout en tenant compte pour cela du rôle joué par son public. / This doctoral thesis presents a study of the phenomenon of print copying, study based on the production of German publishers and engravers in the second half of the seventeenth century and the first half of the following century. Some of the main producers of engravings in Germany after the end of the Thirty Years War, starting with the Küsel family in Augsburg, were very much involved in creating and publishing engraved copies. The French seventeenth century printing was a central element in the models used by these engravers. When these copies are placed in their historical, technical and artistic background, they enable us to address a different way of looking at the copying and publishing of pictures, compared withtoday. We shall, therefore, analyze three levels of transfers. The first one relates to the actual technique of the copyist who transfers the model onto an engraving plate. The second one focuses more specifically on the exchanges generated from one country to another. Finally, the third one raises the issue of how the desire to appropriate the original is transferred onto the copy. We shall thus place these phenomena of print copies in their respective backgrounds but also analyze what is implied by this practice, taking into account the role played by its audience.
126

La création artistique : le timbre-poste français gravé en taille-douce de 1928 à nos jours / Artistic creation : the French postage stamp engraved in intaglio from 1928 to the present day

Nowacka, Monika 12 January 2017 (has links)
Nombreux sont les artistes plus ou moins reconnus qui travaillent pour le compte de l’administration postale depuis 1928, année d'émission du premier timbre-poste français gravé en taille-douce. Cette technique, devenue le procédé par excellence de création des timbres-poste en France, se développa et connut des temps forts avec les années 1930 et jusque dans les années 1970. Tous les timbres-poste, à quelques rares exceptions, sont alors gravés par des artistes. Peu à peu, l’apparition de nouveaux procédés de fabrication, tels que l’héliogravure, l’offset et la gravure assistée par ordinateur, s’impose à la taille-douce traditionnelle. Aussi, le poinçon, plaque en acier qui sert de support au graveur, est progressivement remplacé par des procédés électromécaniques et photochimiques permettant d’obtenir des délais d’exécution et des coûts de fabrication bien moindres et sans doute mieux adaptés à des productions industrielles. Cette étude présente une analyse de l’évolution de l’art de la gravure, de sa place et de son rôle dans le domaine de la philatélie durant une période précise, de 1928 à nos jours. Le statut de l’artiste graveur et sa reconnaissance artistique évoluent au même titre que changent le statut de l’administration postale, sa politique et ses besoins liés aux exigences économiques du marché. L’examen approfondi des créations philatéliques, commandes régies par un cahier des charges strict ainsi que des conditions de travail et de l’investissement des graveurs de timbres face à leur métier, a permis de présenter les particularités esthétiques et plastiques de leurs travaux et de leur attribuer une place dans le domaine de l’art. / Many artists, some more famous than others, have worked for the postal administration since 1928, the year of the first issue of an engraved French postage stamp . This technique, which became the most important method of creating postage stamps in France, developed and reached a peak in the 1930s and continued until the 1970s. During this time all postage stamps, with few exceptions, were engraved by artists. Gradually, however, the emergence of new manufacturing processes, such as heliogravure, offset printing and computer-aided engraving, replaced traditional engraving. Also, the stamping device, a steel plate that served as a support for the engraver, was gradually replaced by electromechanical and photochemical processes making it possible to obtain much lower turnaround times and manufacturing costs and was probably better suited to industrial production. This study presents an analysis of the development of the art of engraving, its place and its role in Philately during a specific period, from 1928 to the present day. The status of the engraver and his artistic recognition changed along with the status of the postal administration, its policy and its needs in response to the economic demands of the market. The in-depth review of philatelic creations, orders governed by strict specifications, working conditions and the investment of stamp engravers in their craft, has made it possible to show the aesthetic and plastic features of their work and secure them a place in the art world.
127

Caspar Lehmann: umělec na dvoře Rudolfa II. / Caspar Lehmann: an artist at the court of Rudolf II.

Minaříková, Adéla January 2017 (has links)
Caspar Lehmann is one of the most significant personalities of applied arts in central Europe at the end othe 16th and the beginning of 17th century. As an engraver of glass and precious stones he worked at the court of emperor Rudolf II. in Prague, but also at the court of the elector Christian II in Dresden. Considerable interest in his work was caused mainly by the claim of Joachim von Sandrart from 1675 stating that Caspar Lehmann was granted a privilege for glass engraving. Discovery of a signed beaker in late 19th century further sparked the existing interest in his production. Based on the similarities with the beaker, several other works were subsequently attributed to Lehmann, despite significant differences in quality and style of engraving. The present work summarizes Lehmanns life based on a thorough study of previous literature and archive materials. Main part of the work includes detailed analyses of 26 artifacts which were previously attributed to Lehmann. Based on their comparison it attempts to define a characteristic technique Lehmann used for carving, and subsequently to critically assess his authorship. The thorough comparisons of the existing objects suggest that three portrait pannels (Moritz von Oranien, Johann Sigismund von Brandenburg, and Johann Friedrich von Württemberg)...
128

Design e tecnologia: manufatura aditiva por sinterização de poliestireno em equipamento de gravação e corte a laser / Design e technology: additive manufacturing by polystyrene sintering using a laser cutting and engraving machine

Ribeiro, Thiago Rafael Rodrigues January 2018 (has links)
A sinterização a laser (SL), uma das tecnologias de manufatura aditiva (MA), se mostra de grande interesse devido a uma série de características, mas, principalmente, devido a sua capacidade de processar uma ampla gama de materiais em pó, a qual amplia possibilidades de pesquisa e desenvolvimento no campo do Design. Neste trabalho, sob o prisma da MA, tem-se por objetivo realizar a sinterização a laser em um equipamento de gravação e corte a laser convencional, sem pré-aquecimento do material. No desenvolvimento do estudo, foi utilizado um equipamento galvanométrico a laser para a realização de experimentos de sinterização de poliestireno em pó (PS 200). Os ensaios de caracterização desse material polimérico amorfo, constataram o diâmetro médio dos grãos de 54,3 μm em formato irregular. Para viabilizar o processo proposto, investigaram-se os parâmetros de processo para a SL, valendo-se de um dispositivo de controle da altura da mesa de trabalho. A melhor amostra (geometria circular) foi construída com potência 20 W, velocidade de varredura de 200 m/min e distância entre linhas de varredura do feixe laser de 0,1 mm. Esse último parâmetro, é relacionado ao diâmetro do foco do feixe laser, o qual foi estimado pelos ensaios em 0,3 mm. Com isso, foi calculada a densidade de energia transferida para o material, conhecida como Número de Andrew (An), em 0,06 J/mm² Análises visuais, macroscópicas e microscópicas, antes e depois da sinterização de uma camada (2D) e de camadas empilhadas (3D), além de sua digitalização tridimensional, foram realizadas. As amostras apresentaram deformação no plano x-y (elipticidade), no eixo z (empenamento) e grande porosidade. Nos ensaios de empilhamento de camadas foi determinada, para os parâmetros utilizados, a espessura de camada de 0,15 mm. Posteriormente, foi construído um modelo 3D com 100 camadas, o qual apresentou um acabamento liso na maior parte de sua lateral, porém, foram observadas estrias verticais ao longo da sua altura, as quais foram consideradas como característica do processo (devido à inércia dos espelhos galvanométricos). Por fim, esses parâmetros foram validados em um ensaio valendo-se de uma forma orgânica (face humana) em escala 1:4. O fator crítico foi o empenamento, o qual prejudica a distribuição de novas camadas de pó, mas pôde ser contornado com espessuras de camada de alturas superiores a esse empenamento. Assim, considera-se que para a viabilização prática do processo de sinterização proposto, em equipamentos de corte e gravação a laser convencionais, torna-se importante o desenvolvimento de um dispositivo de distribuição de pó automatizado, o qual permitiria a construção de modelos 3D de maior tamanho e complexidade. / Laser sintering (SL), one of the additive manufacturing (MA) technologies, is of great interest due to a number of characteristics, but mainly due to its ability to process a wide range of powder materials, which offers possibilities for research and development in the Design’s field. In this work, under the prism of the MA, the goal is to perform laser sintering in a conventional laser engraving and cutting equipment, without preheating the material. In the development of the study, a galvanometric laser equipment was used to perform powder polystyrene (PS 200) sintering experiments. The characterization tests of this amorphous polymer material showed the average grain diameter of 54.3 μm in irregular shape. In order to make the proposed process feasible, the process parameters for the SL were investigated, using a device to control the height of the workbench. The best sample (circular geometry) was built with 20 W power, laser scan speed of 200 m/min and distance between scanned lines of 0.1 mm. This last parameter is related to the diameter of the laser beam waist, which was estimated by the tests in 0.3 mm Thus, the energy density transferred to the material, known as Andrew's Number (An), was calculated at 0.06 J/mm². Macroscopic and microscopic visual analysis, before and after the sintering of a two-dimensional layer (2D) and of stacked layers (3D), in addition to its 3D scanning, were performed. The samples displayed deformation in the x-y plane (ellipticity), at the z-axis (warpage) and high porosity. In the layer stacking tests, the layer thickness of 0.15 mm was determined for the parameters used. Next, a 3D model with 100 layers was sintered, which presented a smooth finish in most of its lateral, however, vertical streaks were observed along its height, which were considered as characteristic of the process (due to the inertia of the galvanometric mirrors). Finally, these parameters were validated in an assay using an organic form (human face) in a 1: 4 scale. The critical factor was the warpage, which impairs the distribution of new layers of powder, but could be worked around with layer thicknesses of heights higher than this warpage. Thus, it is considered that for the practical feasibility of the proposed sintering process in conventional laser cutting and engraving machine, it is important to develop an automated powder distribution device, which would allow the construction of greater size and complexity 3D models.
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Le rôle des peintres dans l'illustration des livres imprimés à Paris, 1530-1580 / The role of painters in the Parisian printed book illustration, 1530-1580

Baydova, Anna 09 December 2017 (has links)
Principal centre d’imprimerie du XVIe siècle, rassemblant les auteurs et les forces artistiques du royaume, Paris offre un échantillon parfait pour l’étude de l’illustration à la Renaissance. De 1530 à 1580, la typographie parisienne intègre des influences issues des éditions humanistes italiennes et des particularités artistiques de l’école de Fontainebleau. La participation des peintres à la préparation des illustrations est un fait clairement établi : les noms des dessinateurs sont parfois cités sur les pages de titre et dans le texte des éditions. Cependant, les modalités de leur collaboration avec les différents métiers du livre restent à préciser. Soumis à la commande des éditeurs et au contrôle des auteurs, contraints par la technique de l’élaboration du livre imprimé, les illustrateurs étaient amenés à s’adaptent à ce nouveau médium. Par ailleurs, la diffusion massive des images imprimées a, elle-même, bouleversé les pratiques artistiques. Associant l’étude des œuvres et la recherche des témoignages d’archives, cette étude se retrouve à l’intersection de l’histoire de l’art et de l’histoire du livre. Cette approche croisée permet de déterminer plus précisément la place des peintres dans le monde du livre imprimé parisien et d’analyser en détail leurs réseaux professionnels. La reconstitution des corpus d’illustrations permet l’étude plus précise d’un certain nombre d’artistes particulièrement actifs dans ce domaine, tels que Jean Cousin père, Baptiste Pellerin, Geoffroy Ballain et Charles Jourdain. / Paris presents a prefect example for the study of the book illustration as the main center of printing in the 16th century and where the prolific authors and the artistic forces of the Kingdom concentrated. From 1530 to 1580, Parisian typography integrated the influence of Italian humanist editions and the artistic particularities of the Fontainebleau school. The participation of painters in the preparation of illustrations is a well-known fact: we can sometimes find their names on the title pages and in the texts of books. However, the terms of their collaboration with other book printing trades are still to be clarified. Dependent on book publishers’ command, subjected to the authors’ control and limited by the book printing techniques, the illustrators had to adjust to this new medium. Besides, the massive diffusion of printed images profoundly changed artistic practices. Combining the study of artworks and archives, this research is at the junction of art history and book history. This complex approach highlights the place of painters in the world of the Parisian book printing and allows an analysis of their professional networks. The reconstruction of illustrations corpuses enables the study of the career of some Parisian artists who were particularly active in this field, such as Jean Cousin the Elder, Baptiste Pellerin, Geoffroy Ballain and Charles Jourdain.
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Návrh a realizace CO2 Laseru s výkonem do 100W / Design and realization of CO2 laser with power up to 100W

Šrenk, Jakub January 2021 (has links)
This work is focused on the problematics of small CO2 lasers and their possible use for commercial production. The first part describes devices available on the market and evaluation of their parameters. The practical part specifies the parameters that arise from the potential use of technology. Based on these parameters, design of the machine and its complete mechanical design are elaborated. Furthermore, the experimental part deals with the design of structural components, control system, electrical systems and in general a complex technical-technological solution of the equipment, including economic evaluation of the design. Part of the work is also the construction of the machine itself, including activation, adjustment and debugging for the considered production. The constructed machine was subject to testing to ensure required quality of production.

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