Este estudo se refere a um método para selecionar os materiais plásticos resistentes a riscos mais adequados para peças automotivas. Estabelecer este procedimento é fundamental para as montadoras devido à versatilidade, qualidade e custo competitivo que os polímeros apresentam. Contudo, essa é uma atividade árdua, pois nota-se a ausência de profissionais familiarizados em trabalhar com materiais plásticos e a existência de milhares de materiais disponíveis para utilização. Deste modo, formular um processo estruturado para facilitar a seleção de plásticos tem como objetivo minimizar os riscos e erros do projeto. Portanto, o processo concebido para esta pesquisa foi gerado a partir da estratégia de seleção desenvolvida por Ashby, método tido como referência na área. Além deste, também foram utilizados conceitos da matriz de decisão de Pahl & Beitz, incluindo índice de mérito. Dois exemplos de aplicação da metodologia são apresentados através de estudos de caso, com os componentes tampa do porta-luvas e base do espelho lateral. / This dissertation work is focused on a method to select the most suitable plastic material with scratch resistance for automotive parts. This process is essential for the automakers due to the versatility, improved quality and cost competitiveness of resin materials. Nonetheless, the lack of professionals specialized in plastic materials and the large variety of polymeric materials makes the proper material selection challenging. In this way, it is necessary to define a systematic method to simplify polymeric materials selection in order to reduce the project risks and errors. For this reason, the process proposed in this study was generated based from the selection strategy developed by Ashby, as this is a reference in the field. In addition, two other concepts were adopted: Pahl & Beitz decision matrix and merit index. In order to evaluate this systematic method, two case studies were analyzed: glove compartment and side mirror base.

Submitted by Cristiane Chim (cristiane.chim@ucpel.edu.br) on 2017-05-22T14:11:11Z No. of bitstreams: 1 Carolina Campos.pdf: 5605891 bytes, checksum: 8aa012d3181655f9ee5a53d3ab4d6a7f (MD5) / Made available in DSpace on 2017-05-22T14:11:11Z (GMT). No. of bitstreams: 1 Carolina Campos.pdf: 5605891 bytes, checksum: 8aa012d3181655f9ee5a53d3ab4d6a7f (MD5) Previous issue date: 2016-12-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES# / #2075167498588264571# / #600 / Learning what seems relevant to the academic formation deserves the constant scientific investigation for the world we live in. Today, communication technologies are a part of the personal and professional lives of adults and youth in ways never seen before. The formal education environment, on the other hand, doesn’t look into the same technologies as allies to the classroom learning, and so many times builds a wall between communication tools that students love to use and their scholar curriculum. Considering the necessity of discussion on learning in informal environments, this thesis was made with the goal of bringing to the surface, using educational studies for this context, a learning model for discussions in online forums. To accomplish that, we present the case of Scratch, a tool used for the creation of projects through blocks language, from computer science. Using Scratch’s online discussion forums, we collected data from its participants’ conversations, and visualized the data using Social Network Analysis (SNA) tools to see these groups’ content and members as a network. Our research corpus consists of data from eight (8) online forums, collected in two moments: August and September 2015; and again in August and September of 2016. Later, we did the data analysis: first the network one, highlighting who were the most influential participants in the forums and what roles they have played on it; and then, by the content analysis, it was possible for us to understand the subjects that users talked about most, and also to see the frequency of word pairs appeared in the discussions. As a contribution to the first two analyses, we’ve clipped 20 messages found in our corpus data as a complement to the understanding of data context. Finally, we based our thesis on the Connected Learning theories (ITO ET AL, 2013) to point in the results what can be like this considered in the actors relations. Composing the final purpose of this research, we propose the connected learning model in Scratch, creating a typology for its members’ ways of participation. In the end, we suggest new ways of participation that might be applied to Scratch or other communities so it can direct its members’ activities to a learning model based on social interactions. / Aprender informalmente o que é relevante à formação acadêmica merece o constante aprofundamento científico necessário ao contexto em que vivemos atualmente. Hoje, as tecnologias de comunicação fazem parte da vida pessoal, escolar e profissional de adultos, jovens e crianças como jamais o foi anteriormente. O ambiente escolar formal, no entanto, não busca nas mesmas tecnologias aliados para trabalhar a aprendizagem em sala de aula, e muitas vezes constrói um muro entre as ferramentas de comunicação que os alunos têm prazer em utilizar e o currículo escolar. Considerando a necessidade de discussão sobre aprendizagens em ambientes informais, esta tese foi realizada objetivando trazer à tona, observando estudos sobre a educação nesses contextos, um modelo de aprendizagem em fóruns de discussão online. Para isso, apresentamos o caso do Scratch, uma ferramenta utilizada para a criação de projetos por meio da programação em linguagem de blocos, utilizada na computação. Considerando os fóruns online do Scratch, extraímos dados de conversações realizadas por seus participantes, e os configuramos enquanto grafos por meio de ferramentas da Análise de Redes Sociais (ARS), para observarmos a constituição desses grupos enquanto rede e no que se refere ao conteúdo das conversações ali expostas. Por corpus do estudo, selecionamos dados de oito (8) fóruns, coletados em dois momentos: agosto e setembro de 2015; e, em 2016, no mesmo período, passado um ano da primeira coleta. Posteriormente, realizamos a análise dos dados, primeiramente com a análise de redes, destacando quais foram os participantes mais influentes nos fóruns e o papel que desempenharam. Já pela análise de conteúdo foi possível entender os temas mais abordados pelos usuários, sua continuidade ou desistência, e as co-ocorrências de palavras existentes nessas discussões. Em contribuição às duas primeiras formas de análise, buscamos em 20 recortes de mensagens nos fóruns integrantes do corpus o complemento para compreendermos o contexto dos dados. Finalmente, nos baseamos nas teorias da Aprendizagem Conectada (ITO ET AL, 2013) para apontar nos resultados o que pode ser constituído como tal nas interações entre os sujeitos da pesquisa. Constituindo a proposta final deste trabalho, propomos o modelo de aprendizagem conectada do Scratch, criando para isso uma tipologia dos modos de participação de seus integrantes. No fechamento, sugerimos, ainda, novos modos de participação que podem ser aplicados ao Scratch para que o mesmo direcione as atividades de seus integrantes à aprendizagem baseada em interações sociais.

In order to successfully incorporate the tremendous possibilities of nanoscale applications into devices and manufacturing, significant studies need to be conducted of the properties and mechanics of materials of this small scale. In this thesis, the effect of repeated scanning of KBr, aluminum, and gold was studied by using a nanoindenter and Atomic Force Microscope (AFM) in varying environments. Additional research was performed to study the environmental effects of gold film scratching using a Taber Shear/Scratch Tester. Scanning of KBr single crystal surface in air with a diamond tip in the Hysitron Triboindenter formed surface ripples 100 nm high, 1 micron apart. It has been observed that the nanoripple's initial height and period increase with the number of repeated scans. The surface ripples form perpendicular to the scanning direction, beginning at the bottom of sloped samples and working their way up the entire scan area. The addition of water to a wear experiment on gold film produced considerably deeper wear areas than its ambient air counterpart in both scanning machines. Scratch testing with a conical diamond tip of 77 µm radius with 125 g normal load also produced deeper wear tracks in water than in ambient air conditions. Several mechanisms may be responsible for the ripples formation, including dislocation dynamics, chatter, piezo hysteresis and others. Most likely there is a combination of effects, with a clear differentiation between nanoripple's origination and propagation. Mechanisms responsible for rippling, including system dynamic response and stick slip behavior are investigated. Topography modification appears to be the main result of ambient wear tests at the nanoscale, whereas much higher wear rate and nanoripples are observed in water. It is possible that this moisture is assisting grain fracture and pull off.

The Gram-negative bacterium Bartonella henselae (Bh) is an emerging zoonotic pathogen that has been associated with a variety of human diseases including bacillary angiomatosis which is characterized by vasoproliferative tumor-like lesions on the skin and internal organs of some immunosuppressed individuals. Several virulence factors associated with Bartonella-induced pathogenesis have been characterized. However, the study of those virulence factors has been limited to in vitro cell culture systems due to the lack of a practical animal model. Therefore, we wanted to investigate whether the zebrafish embryo (Danio rerio) could be used to model human infection with Bh. We investigated if Bh can mount an infection in zebrafish embryos during their early stage of development. Our data showed that Tg(fli1:egfp)y1 zebrafish embryos supported a sustained Bh infection for 7 days with >10-fold bacterial replication when inoculated in the yolk sac. This was evident by plating of zebrafish homogenates, quantitative PCR, and confocal microscopy analysis. We assessed the interaction of Bh with EC and the phagocytic cells in live embryos by microscopy. Our data showed that aggregates of Bh interact with the endothelium of the embryo vasculature. Evidence showed that Bh recruited phagocytes to the site of infection in the Tg(mpx:GFP)uwm1 embryos. We also wanted to determine the response to infection with Bh. Infected embryos showed evidence of a Bh-induced angiogenic phenotype as well as an increase in expression of genes encoding pro-inflammatory factors and pro-angiogenic markers. A deletion mutant for the entire VirB type IV secretion system (ΔvirB2-11 supported bacterial replication although to a lesser degree compared to the wild type control. However, infection of zebrafish embryos with a deletion mutant in the major adhesin (BadA) resulted in little or no bacterial replication and a diminished pro-angiogenic and pro-inflammatory host response compared to wild type Bh, providing the first evidence that BadA is critical for in vivo infection. Thus, the zebrafish embryo provides the first practical animal model of Bh infection that will facilitate efforts to identify virulence factors and define molecular mechanisms of Bh pathogenesis.

Scratch-pad memory (SPM), a fast on-chip SRAM managed by software, is widely used in embedded systems. Compared to hardware-managed cache, SPM can be more efficient in performance, power and area cost, and has the added advantage of better time predictability. In this thesis, SPMs should be seen in a general context. For example, in stream processors, a software-managed stream register file is usually used to stage data to and from off-chip memory. In IBM's Cell architecture, each co-processor has a software-managed local store for keeping data and instructions. SPM management is critical for SPM-based embedded systems. In this thesis, we propose two novel methodologies, the memory colouring methodology and the perfect colouring methodology, to place the static data aggregates such as arrays and structs of a program in SPM. Our methodologies are dynamic in the sense that some data aggregates can be swapped into and out of SPM during program execution. To this end, a live range splitting heuristic is introduced in order to create potential data transfer statements between SPM and off-chip memory. The memory colouring methodology is a general-purpose compiler approach. The novelty of this approach lies in partitioning an SPM into a pseudo register file then generalising existing graph colouring algorithms for register allocation to colour data aggregates. In this thesis, a scheme for partitioning an SPM into a pseudo register file is introduced. This methodology is inter-procedural and therefore operates on the interference graph for the data aggregates in the whole program. Different graph colouring algorithms may give rise to different results due to live range splitting and spilling heuristics used. As a result, two representative graph colouring algorithms, George and Appel's iterative-coalescing and Park and Moon's optimistic-coalescing, are generalised and evaluated for SPM allocation. Like memory colouring, perfect colouring is also inter-procedural. The novelty of this second methodology lies in formulating the SPM allocation problem as an interval colouring problem. The interval colouring problem is an NP problem and no widely-accepted approximation algorithms exist. The key observation is that the interference graphs for data aggregates in many embedded applications form a special class of superperfect graphs. This has led to the development of two additional SPM allocation algorithms. While differing in whether live range splits and spills are done sequentially or together, both algorithms place data aggregates in SPM based on the cliques in an interference graph. In both cases, we guarantee optimally that all data aggregates in an interference graph can be placed in SPM if the given SPM size is no smaller than the chromatic number of the graph. We have developed two memory colouring algorithms and two perfect colouring algorithms for SPM allocation. We have evaluated them using a set of embedded applications. Our results show that both methodologies are efficient and effective in handling large-scale embedded applications. While neither methodology outperforms the other consistently, perfect colouring has yielded better overall results in the set of benchmarks used in our experiments. All these algorithms are expected to be valuable. For example, they can be made available as part of the same compiler framework to assist the embedded designer with exploring a large number of optimisation opportunities for a particular embedded application.

<p>RED Digital Cinema is a rather new company that has developed a camera that has shaken the world of the film industry, the RED One camera. RED One is a digital cinema camera with the characteristics of a 35mm film camera. With a custom made 12 megapixel CMOS sensor it offers images with a filmic look that cannot be achieved with many other digital cinema cameras.</p><p>With a new camera comes a new set of media files to work with, which brings new software applications supporting them. RED Digital Cinema has developed several applications of their own, but there are also a few other software supporting RED. However, as of today the way of working with the RED media files together with these software applications are yet in progress.</p><p>During the short amount of time that RED One has existed, many questions has risen about what workflow is the best to use. This thesis presents a theoretical background of the RED camera and some software applications supporting RED media files. The main objective is to analyze RED material as well as existing workflows and find the optimal option.</p>

The present study employs a standardized progressive load scratch test (ASTM D7027/ISO 19252) to investigate the fundamental physical and mechanistic origins of scratch deformation in styrene-acrylonitrile (SAN) random copolymers. Previous findings from numerical simulation using finite element methods are used to establish correlation between mechanical properties and key scratch deformation mechanisms of the SAN model systems. For SAN, the acrylonitrile (AN) content and molecular weight (MW) can be changed to alter mechanical properties such as tensile strength and ductility. The key scratch deformation mechanisms are identified as: scratch groove formation, scratch visibility, periodic micro-cracking and plowing. Groove formation has been correlated to the secant modulus at the compressive yield point while micro-cracking and plowing are related to the tensile strength of the material. The fundamentals and physical origins of scratch visibility are discussed. It is explained how unbiased evaluation is accomplished by means of an automatic digital image analysis software package (ASV®). Frictional behavior and the effects of scratch speed and moisture absorption are also addressed. Increasing the AN content and/or the MW of the SAN random copolymers generally enhances the scratch resistance of the material with regard to the onset of the key deformation mechanisms. Increasing the scratch speed increases the brittleness of the material, resulting in failure at lower applied loads. Moisture absorption increases with AN content and imparts a degree of plasticization as the moisture diffuses into the sub-surface. This plasticization initially results in a degradation of scratch resistance with respect to the key deformation mechanisms, but then, after saturation, the moisture on the surface provides lubrication and improves the scratch resistance. It is important to note that polymers are fundamentally different in nature, but the findings of this study serve as an important stepping stone down the path to a deeper understanding of polymer scratch behavior.

Polypropylene films are widely used in industry, especially for packaging purposes. However, these films become statically charged when they are subject to friction. The accumulation of charges in some applications can be harmful, especially for the electronic devices and can cause undesirable appearance due to the attraction of dusts. Furthermore, minimum susceptibility to mechanically induced surface damage is a desired property since scratches reduce the mechanical strength and the bright texture of the film in packaging of commercial items and limit the applications of the material. This study aims to provide antistatic character to polypropylene films by the utilization of conductive fillers which function independent of humidity and enhance their scratch resistance by means of aromatic based additives. Polypyrrole-polypropylene composites including 2%, 5%, 7% and 9% pyrrole were synthesized by chemical modification. 2% of pyrrole was adequate to provide antistatic character to the films. Moreover, they attained conductive property when the pyrrole content exceeds 7%. Polypropylene based materials containing four different compositions of 1,7-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, pphenylene diamine and hydroquinone were prepared by mechanical mixing. Scratch resistance of polypropylene films increased significantly with the insertion of additives. The material containing 2% 1,7-dihydroxynaphthalene introduced the highest enhancement by more than 60%. Moreover, mechanical analysis results showed that insertion of the additives except hydroquinone increased Young&amp / #8217 / s modulus of the polypropylene films. In addition, tensile strength and elongation at break of polypropylene films were enhanced significantly with insertion of the additives regardless of the additive type.

In the present study the effects of addition of organically functionalized boehmite nano-particles on the mechanical properties of epoxy polymers were analyzed. Nanosize platelets of boehmite powders were produced via a hydrothermal process from the raw material aluminum trihydroxide Al(OH)3 provided by a a chemical supplier, but which in future studies can be replaced by local resources of aluminum trihydroxide available in Seydisehir, Turkey. The ground aluminum trihydroxide particles were submitted to a two-step preliminary ageing procedure in different pH media. Particles were then converted to boehmite nanoparticles via hydrothermal ageing at high pressure and temperature. The product&lsquo / s chemical identity, size, structure and morphology were characterized with XRD, FT-IR, SEM and PSA analyses. By controlling the pH and the ageing time as parameters, hexagonal shaped nanoplatelets were obtained with dimensions ranging from 100 to 500 nm. Aiming at using these nanoparticles into surface coating polymers, the most favorable shape is the plate-like morphology, leading to adopting the last hydrothermal condition in the rest of the study. v The boehmite crystal surfaces are furnished with hydroxyls which can potentially be reacted with epoxy monomers of bisphenol A diglycidyl ether with the help of tin (II) chloride as catalyst through ring-opening reactions. The FT-IR and quantitative analyses indicated that this surface functionalization is possible under a temperature 80 oC and a weight ratio of 5:1 epoxy monomer to boehmite powder These novel inorganic/organic hybrid materials were then mixed with epoxy/hardener resin mixture to obtain nanocomposites. The properties of the composites were characterized accordingly with tensile, impact, micro hardness, micro-scratch tests, DMA analysis and observed with SEM analysis. A deterioration of the tensile strength from the neat polymer was observed, with a distinct trend between the functionalized and non-functionalized boehmite-epoxy polymers. The functionalized polymers showed a less deteriorative character. The tensile modulus instead showed a little improvement of (4%) in 5wt% loaded polymers. DMA analysis results revealed an improved glass transition temperature in the nanocomposites as well as in storage and loss modulus. As aimed in this work, the functionalized boehmite-epoxy polymers displayed a clear improvement in comparison to both non-functionalized and neat polymers in surface coating properties in hardness and scratch resistance.

Bacillary angiomatosis (BA), one of the clinical manifestations resulting from infection with the facultative intracellular bacterium Bartonella henselae, is characterized by angiogenic lesions. Endothelial cells have been identified as host cells for this pathogen and are presumed important for pathogenesis as lesions contain bacteria in direct contact with the endothelium. Lesions also contain infiltrating macrophages, which contribute to the angiogenic process during B. henselae infection by secreting vascular endothelial growth factor (VEGF). While virulence factors have been characterized, and the role for macrophages in B. henselae infection has been established, endothelial cell mediators of angiogenesis have not been well defined. We investigated three potentially important pathways that are triggered by the bacterial interactions with endothelial cells. We examined the ability of endothelial cells to upregulate the chemokines monocyte-macrophage chemoattracta nt protein-1 (MCP-1) and CXCL8 and the mechanism by which B. henselae secreted proteins (BHSP) induce endothelial cell proliferation. We determined that MCP-1 production is upregulated in response to B. henselae infection, which very likely contributes to angiogenic lesion formation by recruiting the VEGF-secreting macrophage. The chemokine CXCL8 is an important mediator of angiogenesis which can cause endothelial cell survival, proliferation, and capillary tube formation. We determined that CXCL8 is secreted from B. henselae-infected cells and contributes to B. henselae-induced angiogenesis in an autocrine manner. We also investigated the role of Ca2+ signaling during B. henselae infection. We determined that BHSP induce a robust intracellular Ca2+ response in HUVEC which originates from intracellular Ca2+ pools. Additionally, endothelial cell proliferation in response to BHSP required Ca2+ activity, indicating a role for intracellular Ca2+ pools during B. henselae-induced angio genesis. Endothelial cell proliferation during B. henselae infection possibly indicates a mechanism by which a pathogen induces proliferation of its host cell in order to propagate its own survival. Numerous factors culminate in the vascular lesions that are characteristic of BA. B. henselae infection represents an important and unique model for pathogen-triggered angiogenesis, and studies into the specific mechanisms of this process may elucidate host cell-pathogen interactions as well as pathways of pathogenic angiogenesis.