No presente trabalho foi investigada a nitretação a plasma do aço rápido ASTM M2 utilizando diferentes configurações, envolvendo as técnicas convencional e com tela ativa. Na técnica convencional, o material a ser nitretado atua como o cátodo do sistema, sendo coberto diretamente pela bainha da descarga luminescente. Nos tratamentos conduzidos com a técnica de tela ativa, uma estrutura de tela em formato cilíndrico atua como cátodo e o material a ser nitretado é posicionado no seu interior. Neste novo processo, como não há potencial elétrico externo aplicado aos substratos, a descarga luminescente se desenvolve apenas na estrutura da tela, evitando problemas intrínsecos do método convencional de nitretação a plasma. Todos os tratamentos investigados foram executados com os seguintes parâmetros: Temperatura de 500 °C, mistura gasosa composta 76% de volume de gás nitrogênio e 24% de volume de gás hidrogênio e pressão de 3 milibar. Para os tratamentos com tela ativa, os substratos foram mantidos eletricamente isolados. Os resultados foram comparados observando a diferença de método de nitretação (com e sem o uso de tela ativa) e a influência do tempo de tratamento (variando sua duração em 1, 4 e 8 horas) Todos os experimentos foram realizados utilizando uma fonte de potência de tensão retificada aplicada na tela ou nas amostras, dependendo da configuração. Adicionalmente, para o tempo de nitretação de 4 horas uma fonte de potência com tensão pulsada também foi aplicada. As amostras nitretadas foram caracterizadas por ensaios de rugosidade, ensaios de dureza e microdureza, microscopia ótica, microscopia eletrônica de varredura e difração de raios-X. Ensaios tribológicos para avaliação da resistência ao desgaste das diferentes condições de tratamento foram conduzidos. Dentre os principais resultados foi observada uma clara diferença na profundidade de camada nitretada, que foi sempre mais profunda nos tratamentos convencionais. Apesar de formadas camadas menos profundas, as amostras nitretadas oriundas dos tratamentos com tela ativa demonstraram melhor desempenho nos ensaios tribológicos, resultando em taxas de desgaste até sete vezes inferior do que as amostras do nitretadas convencionalmente, este resultado foi atribuído a não formação da zona de compostos nas amostras nitretadas com tela ativa. / In the present work an investigation on the plasma nitriding of ASTM M2 High-Speed Steel using different configurations was carried out, involving traditional and active screen techniques. In the traditional technique, the material to be nitrided act as the system cathode, being directly covered by the glow discharge sheath. In the active screen treatments, a cylindrical mesh structure (screen) plays the role of the cathode and the material to be nitrided is positioned in its interior. In this new process, as there is no external electric potential applied to the specimens, the glow discharge develops only in the screen structure, avoiding intrinsic problems from the conventional plasma nitriding method. All the studied treatments were carried out with the following parameters: temperature of 500 °C, gas mixture of 76 vol.-% N2 and 24 vol.-% H2 and pressure of 3 millibar. For the active screen treatments, the samples were kept electrically insulated. The results were compared observing the differences in the nitriding method (with and without the use of active screen) and the nitriding time influence (varying its duration in 1, 4 and 8 hours) All experiments were carried using a rectified voltage power supply applied to the screen or to the samples, depending on the configuration. Additionally, for the nitriding time of 4 hours a pulsed voltage power supply was also employed. The nitrided samples were characterized by roughness tests, hardness and microhardness tests, optical microscopy and scanning electron microscopy, X-ray diffraction. Tribological tests to evaluate the wear resistance of the different treatment conditions were also carried out. Among the main results a clear difference in the case layer depth was noticed, which was always deeper in the conventional treatments. Although forming shallower case depths, the active screen nitrided specimens presented better performance in the tribological tests, resulting in wear rates up to seven times lower than the wear rate for conventionally plasma nitrided samples, this result was assigned due to the non-formation of compound layer in the active screen plasma nitrided samples.

Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2016-07-18T18:55:19Z No. of bitstreams: 1 Julieth Corrêa Paula_.pdf: 3746171 bytes, checksum: 29f4d01bbafe2ed19d3976f1bdb133b1 (MD5) / Made available in DSpace on 2016-07-18T18:55:19Z (GMT). No. of bitstreams: 1 Julieth Corrêa Paula_.pdf: 3746171 bytes, checksum: 29f4d01bbafe2ed19d3976f1bdb133b1 (MD5) Previous issue date: 2016-04-08 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Interessados em compreender as potencialidades fotográficas para além de suas fronteiras, entendemos o print screen (captura de tela) como um processo alternativo ao ato fotográfico convencional. Baseada nessa premissa, a presente dissertação aborda os modos como o fotográfico se inscreve nas imagens produzidas através do print screen. As reflexões de Flusser, Bellour, Couchot, Soulages e Machado sobre a imagem técnica orientam a construção do objeto no contexto da cultura digital. A fundamentação teórica se deu em consequência dos princípios epistemológicos oriundos da Teoria das Materialidades da Comunicação. Para dar conta de um conjunto tão heterogêneo de imagens, propomos uma metodologia que articula dois gestos heurísticos: o tatear, nos termos de Flusser e as constelações benjaminianas. A partir deles, realizamos um mapeamento dos usos do print screen e sistematizamos as imagens em nove categorias: Método de pesquisa, Uso cotidiano, Google Street View, Videochat, Narrativa de videogame, Artes Visuais, Citacional, Tutorial e Redes sociais. Traçamos duas linhas imaginárias que atravessam essas constelações e estruturam o material empírico. A primeira linha indica as imagens informativas, resultantes de processos que partem de dados do mundo concreto. Já a segunda linha abrange as imagens redundantes, computadorizadas, isto é, geradas por meio de cálculos numéricos. Dada essa composição, selecionamos duas obras da constelação Artes Visuais – as séries Pulsão escópica, de João Castilho, e DSL, de Eric Rondepierre – e oito screenshots de Narrativas de videogame, de vários autores. Observando esse corpus, identificamos elementos como a pausa, o enquadramento, a textura, o grau de analogia com a realidade, que fixam as especificidades técnica e estéticas do fotográfico. / Interesados en comprender las potencialidades fotográficas más allá de sus fronteras, entendemos el print screen (captura de pantalla) como un proceso alternativo al acto fotográfico convencional. Basados en esta premisa, esta disertación analiza los modos en que el fotográfico está inscrito en las imágenes producidas por el print screen. Las reflexiones de Flusser, Bellour, Couchot, Soulages y Machado sobre la imagen técnica guían la construcción del objeto en el contexto de la cultura digital. La fundamentación teórica se dio como resultado de los principios epistemológicos derivados de la Teoría de las Materialidades de la Comunicación. Para llevar a cabo un conjunto tan heterogéneo de imágenes, proponemos una metodología que articula dos gestos heurísticos: el tacto, de acuerdo con Flusser, y las constelaciones benjaminianas. A partir de ellos, realizamos un mapa de los usos del print screen y sistematizamos las imágenes en nueve categorías: Método de investigación, Uso diario, Google Street View, Videochat, Narrativas de videojuegos, Artes visuales, Citaciones, Tutorial y Redes sociales. Dibujamos dos líneas imaginarias que se curren a través de estas constelaciones y estructuran el material empírico. La primera línea indica las imágenes informativas, resultantes de los procesos que se parten de los datos del mundo concreto. La segunda línea cubre sólo las imágenes redundantes, computarizadas, que se generan mediante cálculos numéricos. Dada esta composición, seleccionamos dos obras de la constelación de Artes Visuales – las series “Pulsão escópica”, de João Castilho, y “DSL”, de Eric Rondepierre – y ocho screenshots de las Narrativas de videojuegos, de varios autores. Con la observación de este corpus, identificamos elementos tales como el descanso, el encuadre, la textura, el grado de analogía con la realidad, que fijan las especificidades técnicas y estéticas del fotográfico.

Com a popularização dos dispositivos móveis, mais e mais pessoas assistem aos programas de televisão enquanto usam essas plataformas para acessar a web, em busca de informações sobre a atração e para compartilhar opiniões em redes sociais e sites onde a atração está em evidência. A pesquisa aqui apresentada reflete sobre como a convergência entre várias telas interfere na produção de sentido das mensagens apreendidas e na experiência de comunicação, especificamente no caso dos espectadores que assistem aos programas enquanto interagem nas redes sociais digitais Twitter e Facebook. Mais do que isso, quer entender como o jornalismo se posiciona quanto à esse uso simultâneo, aproveitando a seu favor ou não essa duplicidade de fontes de informação. Foram analisadas quatro editorias - esportes, entretenimento, política e cotidiano, por meio da cobertura jornalística de eventos de diferentes proporções e padrões de relevância (nacional e internacional). Os recortes de estudo da dissertação são o Carnaval 2013 - desfile das escolas de samba do grupo especial de São Paulo/SP e Rio de Janeiro/RJ e apresentações de trios elétricos em Salvador, Copa das Confederações FIFA 2013, notícias de três noticiários nacionais (Jornal Hoje, Jornal Nacional e Jornal da Cultura em abril/2014) e cobertura do Jornal da Cultura, Jornal Nacional, Jornal Hoje e Jornal da Globo sobre a votação do Marco Civil da Internet pelo Congresso Nacional brasileiro (março/2014). Em todos os casos analisados, a segunda tela é pouco explorada ou ignorada pela TV. A dificuldade não está na editoria, ao passo que foram analisadas desde específicas - como política e esportes - até geral. Também não é o tamanho do evento, considerando a Copa das Confederações FIFA 2013 que atrai a atenção mundial. A emissora de televisão tão pouco significa muito nesse processo de inaptidão social digital. A limitação está no papel que os comunicadores atribuem à Tecnologia da Informação e Comunicação, priorizando a expansão do alcance das mensagens e não a usando como aliada para a renovação da proposta narrativa de noticiários que serão consumidos na companhia de telas secundárias. / With the popularization of mobile devices, more and more people watch the television programs while using these platforms to access the web, functioning as the second screen in the search for information about the attraction and opinions to share on social networks and websites where the attraction is in evidence. The research presented here reflects on how this convergence of multiple screens interferes with the production of meaning of messages and communication experience, with the focus the viewers while watching programs that are interacting in digital social networks Twitter and Facebook. More than that, how journalism understands that concurrent use, taking advantage of their favor or not the duplicity of information sources. Sports, entertainment, politics and everyday - a few days of news coverage of events in different proportions, patterns of national and international relevance, and four editors were analyzed. Comprise the study analysis of the 2013 Mardi Gras - parade of samba schools of São Paulo / SP and Rio de Janeiro / RJ and presentations of electric trucks in Salvador, FIFA Confederations Cup 2013 news from three national newscasts (Journal Today National Journal and Journal of Culture in abril/2014) and news coverage of the Journal of Culture, National Journal and Journal of the globe on the vote of the Civil Framework Internet by the Brazilian National Congress (março/2014). In all cases analyzed, the second screen is little explored or ignored by television. The difficulty is not in publishing, while we analyze specific long as politics and sports, to general. Nor is it the size of the event, considering the Confederations Cup, which attracts worldwide attention. The television station also involved does not mean much in the digital social awkwardness process. The limitation lies in the role that communicators attach to Information Technology and Communication, using the priority to support expansion of the message and not as allies to the proposed renewal of the narrative of newscasts that will be consumed in the company of secondary screens.

The purpose of this study was to investigate the relationship between home environment and school readiness of children entering kindergarten in a rural East Tennessee county. Family and home environment variables included family income, family structure, parents' education, participation in literacy activities, availability of home learning tools, and amount of children's television viewing. A self-reported parent survey was used to gather information about the family environment; the Brigance K Screen was used to determine entering kindergartner's readiness for school. Three hundred and thirty eight children and parents participated. An initial analysis of data incorporated simple descriptive statistics in the form of frequency tables. To examine the relationships between the dependent variable (Brigance scores) and independent variables (family characteristics/environment), Kendall's tau-b and Cramer's V were used. Independent sample t-tests and analyses of variance (ANOVAs) analyzed differences in Brigance scores between groups. Finally, a hierarchical multiple regression analysis determined if kindergarten readiness could be predicted by specific variables: socioeconomic status, literary resources, and literacy activities. The analysis of relationships in this study indicated that family income was more closely related to success on the Brigance K Screen than any other variable; next in importance were the levels of fathers' education and mothers' education. Significant positive correlations also indicated the value of parents reading to their children, educational outings, availability of educational tools--specifically, a home computer, family structure, mealtime conversation, and the number of children's books in the home. A significant negative correlation was found between the duration of television viewing and Brigance scores; increased television viewing time was significantly related to lower test scores. ANOVAs and t-tests indicated significant differences in total Brigance scores of prekindergarten students from different socioeconomic status groups based on family structure, family income, and parents' education levels. Children from two-parent homes scored significantly higher than those from other family situations as did children from higher income homes. In addition, parents' education level was reflected in the Brigance scores; more educated parents had children who scored higher than children with less educated parents. The multiple regression analysis reinforced the statistical significance and magnitude of the relationship between socioeconomic factors and school readiness, but literacy resources and literacy activities also accounted for variance in the scores.

Orientador: Giovani Fornereto Gozzi / Resumo: Dispositivos Eletroluminescentes (EL) são comumente utilizados para iluminação ambiente e transmissão visual de informações, possuem uma enorme gama de aplicações em setores diversos, como para tratamento fototerápico e decoração. Entre as atuais tecnologias, os dispositivos produzidos com compósitos eletroluminescentes têm potencial de emprego em aplicações emergentes devido ao seu baixo custo, flexibilidade mecânica e escalabilidade. Estas vantagens tecnológicas estão atreladas ao fato destes dispositivos poderem ser produzidos utilizando-se técnicas de impressão gráfica, como por exemplo, a técnica de impressão serigráfica. Neste sentido, este trabalho tem como objetivo o desenvolvimento de dispositivos EL totalmente impressos utilizando a técnica de impressão serigráfica. Para tanto, a pasta condutora transparente (PCT) e a pasta de prata (PTF), ambas fornecidas pela empresa TICON, foram utilizadas para a produção de eletrodos transparentes e opacos, respectivamente. A camada ativa dos dispositivos foi produzida com o compósito eletroluminescente (PEL), o qual foi desenvolvido durante o presente estudo. Filmes dos materiais PCT, PEL e PTF foram depositados utilizando-se telas com diversas lineaturas e caracterizados com relação às suas propriedades morfológicas, elétricas e ópticas, com a finalidade de identificar as melhores lineaturas de telas serigráficas para o processamento de cada um dos materiais. Por fim, dispositivos EL do tipo LECEL (Light-Emitting Composite Ele... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Electroluminescent (EL) devices have a wide range of applications. Among current technologies, devices produced with electroluminescent composites have potential for use in emerging applications due to their low cost, flexibility and scalability. Scalability and cost-effectiveness are characteristics also related to device processing methods, amongst which printing techniques, such as screen-printing, are the most appropriated to achieve these goals. Therefore, this research regards on development of screen-printed EL devices. For this purpose, the transparent conductive paste (PCT) and the silver paste (PTF), both sourced by TICON, were used for transparent and opaque electrodes fabrication, respectively. The active layer of the devices have been produced with an electroluminescent composite (PEL) developed during the present study. We have produced screen-printed films with the PCT, PEL and PTF materials using screens with different mesh counts to study the influence of mesh count on the morphological, electrical and optical properties of the films. In addition, we have performed a study regarding the influence of mesh count on the EL device performance parameters. As main result, we have fabricated a screen-printed EL device, using screens with appropriated mesh counts for deposition of each material, which exhibited luminance of 50 cd/m2 (at 110 V) and turn-on voltage of (18 ± 2) V. / Mestre

My work is a tribute to the disintegration of built environments, and the chaos and disturbance that it brings into the idea of what a city should look like. An ode to the ruins that are witnesses to destructive social and economic systems and that tell the stories of the life that once inhabited them. A comment and critique on humanities way of ruining everything: world that we live in and our self; a destructive behaviour that we refuse to admit we have, and desperately try to hide. We polish the façades and fake our appearance in order to keep the illusion. I am discussing the concept of ruin romanticism, comparing the garden ruins of the eighteenth century to the urban exploration of abandoned places of modern society, the fascination for what once was, but are no more and the different feelings these places might arouse. I describe how I through experiments with dying, deconstructed screen printing and distressing, manipulate fabrics to create an illusion of brick walls. And how I through experiments with display, sound and light explore solutions for creating the dystopic atmosphere of abandoned places in a textile installation. My biggest inspiration is the inevitable downfallof the urban landscape and I am romanticising the imperfections and the flaws. I take what is understood as ugly by the rules of aesthetics, make it beautiful, and put it on a pedestal.

Portant sur six adaptations hollywoodiennes de récits de Rider Haggard, Kipling, Conrad et Greene, ce travail analyse la manière dont le cinéma américain retravaille divers aspects des supports littéraires à des fins esthétiques [attention aux détails exotiques, remaniements narratifs, jeu des acteurs, couleurs, décors] et idéologiques [réflexion sur l’impérialisme colonial]. En confrontant les films et les récits qui les précèdent, il s’agit d’examiner la manière dont le cinéma prend appui sur la littérature pour tisser un réseau où transparaît le regard que Hollywood porte sur la tentation impérialiste américaine. / The study focuses on six adaptations of narratives by Rider Haggard, Kipling, Conrad and Greene. It addresses the way Hollywood worked over several aspects of the literary works for aesthetic [attention to exotic details, reshaping of narratives, acting, colours, setting] as well as ideological purposes [a reflection on colonial imperialism]. Comparing the films with their literary antecedents, the study analyses the manner cinema is backed by literature to weave a network of signs which reveal Hollywood’s approach to American imperialist temptation.

The ultimate goal of this project has been to develop a computational model for quantifying the interactions between of a body of fluid and a fibrous surface. To achieve this goal, one has to develop a model to create virtual structures that resemble the morphology of a fibrous surface (Objective-1) as well as a model that can simulate the flow of a fluid over these virtual surfaces (Objective-2). To achieve the first objective, we treated fibers as an array of beads interconnected through viscoelastic elements (springs and dampers). The uniqueness of our algorithm lies in its ability to simulate the curvature of the fibers in terms of their rigidity, fiber diameter, and fiber orientation. Moving on to Objective-2, we considered woven screens for their geometric periodicity, as a starting point. We studied how fiber diameter, fiber spacing, and contact angle can affect the skin-friction drag of a submerged hydrophobic woven screen, and how such surfaces resist against water intrusion under elevated hydro-static pressures (a requirement for providing drag reduction benefits). We also studied the impact of surface geometry and wetting properties on droplet mobility over these surfaces. Laboratory experiment was conducted at various stages throughout this investigation, and good agreement was observed between the experimental data and the results from our numerical simulation.

A stroke is a life-changing event for a patient and his or her family. The acute stroke patient is at risk for developing aspiration pneumonia, whether silent or overt. Prevention of pneumonia in this population requires timely completion and documentation of the bedside swallow screen to identify those patients at risk for aspiration pneumonia; however, anecdotal data from the emergency department at the site of this project suggested that completion and documentation of the screening were inconsistent. Guided by the quality caring model adopted by the project site as well as the logic model, the aim of this project was to evaluate emergency room nurses' compliance with documentation after completing a modified bedside swallow screening. To facilitate documentation compliance, the current bedside screening tool was modified to make it user friendly. Electronic records of stroke patients (n = 104) admitted to the emergency room were monitored for a period of 6 months after implementing the modified bedside swallow screening tool. The findings indicate that implementing the modified bedside swallow screening tool achieved 93% documentation compliance in the electronic records and 100% documentation in patient charts over this 6-month period and clearly identified patients at risk for developing aspiration pneumonia. Further study is recommended to determine the relationship between the results of the modified bedside swallow screening and the development of hospital-acquired pneumonia. Implementation of this modified bedside swallow screening tool can initiate therapeutic measures to reduce the incidence of aspiration pneumonia in the acute stroke patient, resulting in shorter length of hospitalization and reduced health care costs.

Perceptual grouping describes the organization of small elements into larger objects. Research in user interface (UI) design has demonstrated effects of perceptual grouping on attention and navigation. However, grouping can be mediated by a variety of task factors. One such mediator is processing time. Recent discoveries in vision science suggest that elemental grouping can occur in more than one way, depending on how long elements are displayed. These findings have led to a new understanding of perceptual organization of elements in real-world spatial environments. However,these findings had not been explored within the context of UI environments. Time limits to UI are often set by task demands. Exposure time limits may affect perceptual grouping of elements in UI. Here I report a series of experiments that tested global and local pushbutton grouping by time in user interface displays. The research question was to determine whether global or local depictions of pushbutton groupings speed interaction with user interface. Global and local groupings were compared because prior researchers have discovered that global scene properties can be perceived before local scene properties. For this reason, it was hypothesized that global, as opposed to local, depictions of pushbutton groupings would speed human-interface interactions. Global grouping was defined as grouping by relatively large shapes whereas local grouping was defined as grouping by shapes that were relatively small. The difference between global and local grouping was quantitative and defined by comparison. Participants saw pushbutton interface displays on a computer monitor for varied exposure durations and were asked to make decisions about the grouping of pushbuttons in these displays. Responses and reaction times were recorded. The results of the reported experiments suggest that global, as compared to local, groupings are more accessible across stimulus durations. They also suggest that global groupings can be utilized faster than local groupings in unlimited exposures. Taken together, the reported results further our understanding of global and local Gestalt grouping in user interface displays.