Regulador linear de tensão em tecnologia HV-CMOS

Atualmente, assiste-se na nossa sociedade a um recurso e uso massivo de equipamentos eletrónicos portáteis. Este facto, aliado à competitividade de mercado, exigiu o desenvolvimento desses equipamentos com o intuito de melhorar a sua gestão de potência e, obter, consequentemente, maior autonomia e rendimento. Assim, na gestão de potência de um SoC são os reguladores de tensão que assumem um papel de extrema importância. O trabalho realizado ao longo da presente dissertação pressupõe o projeto de um regulador linear de tensão do tipo LDO em tecnologia HV-CMOS, capaz de suportar tensões de entrada de 12V com vista à alimentação de blocos funcionais RF-CMOS com 3,3V e uma corrente de 100mA. Foi implementado através do processo CMOS de 0.35μm de 50V da Austria Micro Systems. A corrente de quiescente do regulador linear de tensão que determina a eficiência de corrente é de 120,22μA. Possui uma eficiência de corrente de 99,88% e um rendimento de 82,46% quando a tensão mínima de entrada é utilizada. O regulador linear de tensão possui uma tensão de dropout de 707mV. A estabilidade do sistema é mantida mesmo com transições de carga de 10μA para 100mA. O regulador possui um tempo de estabelecimento inferior a 2,4μs e uma variação da tensão de saída relativamente ao seu valor nominal inferior a 18mV, ambos para o pior caso. Porém, este regulador possui um undershoot e um overshoot de +- 1,85V.

Tecnologia CAM aplicada no fabrico por fresagem de componentes mecânicos : caracterização do processo de fresagem e dos componentes produzidos

Na fase inicial desta Dissertação foi realizada uma revisão abordando as operações por corte de arranque de apara mais comuns, considerando-se que estas seriam o torneamento, a furação mecânica e a fresagem, sendo esta última operação abordada de uma forma mais detalhada, uma vez que esta operação será o tema central de estudo neste trabalho. Realizou-se também um estudo mais elaborado sobre alguns fundamentos de fresagem como a maquinagem concordante e discordante, fatores que influenciam no acabamento final da maquinagem, diâmetro efetivo de corte para uma ferramenta de topo esférico, flexão da ferramenta, entre outros. Temas como o CAD-CAM, CNC e Engenharia Inversa foram também particularizados neste trabalho, pois o conhecimento destes assuntos por parte do leitor seriam importantes para a compreensão do trabalho posteriormente desenvolvido. Na parte seguinte deste trabalho foi realizada uma parte experimental. Um primeiro trabalho foi desenvolvido com base numa geometria a duas dimensões, onde foi necessária a realização das geometrias no software AUTOCAD® e posterior utilização do MASTERCAM® para criar os ciclos de maquinagem e, para um segundo trabalho, desta vez com base numa geometria a três dimensões, utilizou-se o SOLID-WORKS® para extração da Bucha e Cavidade e o MASTERCAM® para criar os ciclos de maquinagem. Ambos os trabalhos foram produzidos no Centro de maquinagem existente no Departamento de Engenharia Mecânica do Instituto Superior de Engenharia de Coimbra.

A Engenharia Genética como Proposta de Co-Criação vista a Partir do Pensamento do Teólogo Ronald Cole-Turner

Esta dissertação de mestrado busca pesquisar a relação estabelecida pelo teólogo Ronald Cole-Turner, entre a engenharia genética e o conceito de co-criação , desenvolvido como uma alternativa para que se pense o papel do ser humano frente aos desenvolvimentos tecnológicos atuais. Tendo em vista o conceito da evolução, da criação contínua e dos potenciais gerados pela engenharia genética, Cole-Turner defende que o ser humano pode participar das atividades criativas de Deus por meio desta tecnologia, desde que priorize os aspectos redentivos que podem ser extraídos de seu uso. Faz isto em demonstrar, por meio do relato Jawista da criação, como o agir criativo de Deus está relacionado ao agir humano, através de suas tecnologias, e em relacionar os milagres de cura operados por Jesus nos evangelhos, como explicitação epistêmica da vontade de Deus, que pode ser participada pelos seres humanos. O objetivo básico desta pesquisa será o de relatar, no primeiro capítulo, o aspecto teórico da engenharia genética, nas suas possibilidades positivas e negativas. Em seguida, no capítulo segundo, se fará uma exposição do pensamento de Cole- Turner, em diálogo com outros interlocutores do tema. Por fim, no último capítulo, se verificará as respostas oferecidas às várias observações críticas que seu pensamento recebe. A hipótese é a de que, se a criação é um projeto contínuo e inacabado, e o destino dos seres humanos se encontra inserido dentro desta continuidade, seria coerente afirmar que estes possam participar das atividades de Deus em tais projetos. Como a evolução biológica é uma dimensão da criação, que ocorre por meio de transformações no capital genético dos organismos vivos, os seres humanos, tendo conhecimento e habilidade para repetir os processos verificados nestas modificações, poderão empreender seus esforços, tanto na área da técnica, como na da ética, para participarem da consecução dos propósitos de Deus.(AU)

Uma abordagem ergonômica para análise da qualidade do pescado, desde sua captura ao seu desembarque na praia, resultante da atividade dos jangadeiros de Ponta Negra - Natal/RN

The artisan fishing activity, which involves historical - cultural, environmental, social, political, economi c, among other factors, presents, nowadays, as an important source of income, creating jobs and food, contributing to the permanence of man in their own birthplace. However, the fish, considered one of the most perishable foods, requires a proper handling and conservation, from capture to its availability in the market, in order to slow the deterioration process. Thereby, this dissertation aims to study the effect of the manipulation practices on fish quality, from capture to its landing on the beach, resul ting from fisherman’s activity from Ponta Negra - Natal/RN. It also presents the purpose of analyzing the quality of the fish and propose recommendations for their proper handling and possible solutions to add value to the product, through the improvement of the quality and good handling practices. For this purpose, the methodology used was based on ergonomic analysis of their work through observational techniques and interactional with the focus group, the jangadeiros, to understand their activity and eval uated the freshness and quality of the fish by sensory analysis, and microbiological parameters and physicochemical from existing legislation Ordinance No. 185 of May 13, 1997 and RIISPOA - amended on December 1, 2007 and RDC No. 12, dated January 2, 2001. According to the results obtained in laboratory tests, it can be established, the acceptable quality of fish as the existing rules and regulations parameters , not getting significant deterioration caused by poor handling and improper storage of fish.

Transportadores sólidos de oxigênio à base de níquel e cobre suportados em aluminatos para combustão do metano pela tecnologia de recirculação química

In recent years, solid carriers suitable oxygen have been developed for use in different chemical processes recirculation. The success of this technology is directly related to the chemical reactivity and the oxygen storage capacity of the carrier. Thus, research into the development of new materials that can be applied to the process becomes extremely important. Possible candidates are the carriers based on nickel and copper for presenting favorable thermodynamic properties. In this work, aluminates type MAl2O4 (M = Mg and Ca) and M0,9B0,1Al2O4 (B = Ni and Cu) that are used as supports were synthesized by combustion reactions assisted by microwave and calcined at 900°C/2h. Then, the carriers were impregnated with 10% (m/m) of nickel or copper, and subsequently calcined at 600°C/2h to obtain the solid oxygen carriers, which were characterized by X-ray diffraction (XRD) Microscopy scanning electron microscopy (SEM) and temperature programmed reduction (TPR). Reactions simulating the combustion process by chemical recirculation were performed by cycles reduction/oxidation, in order to evaluate the reactivity of carriers. XRD analysis revealed diffraction peaks of the spinel type structures. In the doped substrates were verified the presence of secondary phases, suggesting that all the metal was incorporated into the spinel structure. In solid oxygen carriers, the NiO and CuO phases were observed after impregnation of active phases on different media. The results of evaluations of chemical cycles reduction/oxidation revealed that TSO's impregnated with nickel in various media were more active and are potential candidates for use in the chemical recirculation technology

Análise de tensões integrada a sistema de engenharia reversa para projeto e confecção de próteses

This work consists of the conception, developing and implementation of a Computational Routine CAE which has algorithms suitable for the tension and deformation analysis. The system was integrated to an academic software named as OrtoCAD. The expansion algorithms for the interface CAE genereated by this work were developed in FORTRAN with the objective of increase the applications of two former works of PPGEM-UFRN: project and fabrication of a Electromechanincal reader and Software OrtoCAD. The software OrtoCAD is an interface that, orinally, includes the visualization of prothetic cartridges from the data obtained from a electromechanical reader (LEM). The LEM is basically a tridimensional scanner based on reverse engineering. First, the geometry of a residual limb (i.e., the remaining part of an amputee leg wherein the prothesis is fixed) is obtained from the data generated by LEM by the use of Reverse Engineering concepts. The proposed core FEA uses the Shell's Theory where a 2D surface is generated from a 3D piece form OrtoCAD. The shell's analysis program uses the well-known Finite Elements Method to describe the geometry and the behavior of the material. The program is based square-based Lagragean elements of nine nodes and displacement field of higher order to a better description of the tension field in the thickness. As a result, the new FEA routine provide excellent advantages by providing new features to OrtoCAD: independency of high cost commercial softwares; new routines were added to the OrtoCAD library for more realistic problems by using criteria of fault engineering of composites materials; enhanced the performance of the FEA analysis by using a specific grid element for a higher number of nodes; and finally, it has the advantage of open-source project and offering customized intrinsic versatility and wide possibilities of editing and/or optimization that may be necessary in the future

Especificações e concepções de front-end UHF integrado e multipadrão em tecnologia CMOS 130nm

The Brazilian Environmental Data Collecting System (SBCDA) collects and broadcasts meteorological and environmental data, to be handled by dozens of institutions and organizations. The system space segment, composed by the data collecting satellites, plays an important role for the system operation. To ensure the continuity and quality of these services, efforts are being made to the development of new satellite architectures. Aiming a reduction of size and power consumption, the design of an integrated circuit containing a receiver front-end is proposed, to be embedded in the next SBCDA satellite generations. The circuit will also operate under the requirements of the international data collecting standard ARGOS. This work focuses on the design of an UHF low noise amplifier and mixers in a CMOS standard technology. The specifi- cations are firstly described and the circuit topologies presented. Then the circuit conception is discussed and the design variables derived. Finally, the layout is designed and the final results are commented. The chip will be fabricated in a 130 nm technology from ST Microelectronics.

Interface para tecnologia assistiva baseada em eletrooculografia

We propose in this work, a new method of conceptual organization of areas involving assistive technology, categorizing them in a logical and simple manner; Furthermore, we also propose the implementation of an interface based on electroculography, able to generate high-level commands, to trigger robotic, computer and electromechanical devices. To validate the eye interface, was developed an electronic circuit associated with a computer program that captured the signals generated by eye movements of users, generating high-level commands, able to trigger an active bracing and many other electromechanical systems. The results showed that it was possible to control many electromechanical systems through only eye movements. The interface is presented as a viable way to perform the proposed task and can be improved in the signals analysis in the the digital level. The diagrammatic model developed, presented as a tool easy to use and understand, providing the conceptual organization needs of assistive technology

Estudo comparativo da capacidade de assamento de dois fornos solares com diferentes configurações

This research is presented as a comparative study about the baking capacity of two box type ovens, produced from a packing case used to equipment transportation. The two ovens have different internal settings, with the greenhouse effect and the concentration of incident solar radiation as the main parameters of differentiation. The main features of the ovens are the low cost, the reuse of materials, the manufacturing and assembly processes simplified, the easy management and the ability of baking a variety of foods simultaneously. The manufacturing and operation of the ovens can be handled by any social and intellectual level of people. The feasibility of the ovens to bake the tested foods was proved with success, ensuring the supremacy of the mirrored oven. The results obtained for both ovens were competitive even with the conventional gas oven, producing the baking of three cakes with 750g in just 80 minutes.

Características bioativas, funcionais e efeito protetor do resíduo desidratado de camu-camu (Myrciaria dubia H.B.K. (McVaugh)) sobre doenças degenerativas utilizando modelos in vivo C. elegans

Camu-camu (Myrciaria dubia H.B.K. (McVaugh)) is a native Amazon fruit, recognized worldwide as one of the main natural sources of ascorbic acid. Due to its great acidity, this fruit is generally consumed after processing into juice or as ingredient in food preparations. As a co-product of the camu-camu processing, a significant amount of agroindustrial residue is generated. Despite the studies showing the bioactive value and biological potential of the fruit, few studies have approached the possible processing techniques, transformation and preservation of camu-camu fruits and its agroindustrial pomace. Therefore, the present work has the objective of evaluating two different drying processes applied to camu-camu pomace (peel and seeds with residual pulp), freeze drying and hot air drying, in order to obtain a functional fruit product. This thesis was divided into three stages: the first one shows the studies related to the freeze drying and hot air drying, where we demonstrated the impact of the selected drying techniques on the bioactive components of camu-camu, taking the fresh pomace as the control group. Among the investigated conditions, the groups obtained at 50ºC and 4 m/s (SC50) and 80ºC and 6 m/s (SC80) were selected as for further studies, based on their ascorbic acid final content and Folin-Ciocalteau reducing capacity. In addition to SC50 and SC80, the fresh pomace (RF) and freeze dried (RL) samples were also evaluated in these further stages of the research. Overall, the results show higher bioactive concentration in the RF samples, followed by RL, SC50 and SC80. On the second step of the research, the antioxidant, antimicrobial and antienzymatic activities were evaluated and the same tendency was observed. It was also reported, for the first time in the literature, the presence of syringic acid in dried camu-camu pomace. In the third and final stage of the research, it was investigated the effect of dried camu-camu on aging and neuroprotective disorders, using the in vivo model C.elegans. It was observed that camu-camu extracts were able to modulate important signaling genes relevant to thermal and oxidative stresses (p < 0.05). The polar acid, polar basic and polar neutral fractions obtained from the low molecular extracts of SC50 were able to extend the lifespan of wild type N2 C. elegans in 20% and 13% (p < 0.001). Results also showed that the paralysis induced by the β1-42 amyloid was significantly (p < 0.0001) retarded in CL4176 worms. Similarly, the camu-camu extracts attenuated the dopaminergic induction associated to Parkinson’s disease. Finally, a global analysis of the data presented here reveal that the camu-camu pomace, a co-product obtained from the industrial processing of a native Brazilian fruit, is a relevant natural source of health relevant compounds. This thesis, shows for the first time, the multifunctionality of camu-camu pomace, a natural resource still underexploited for scientific, commercial and technological purposes.

Fabricação e estudo de um forno solar com dispositivo de transporte

It presents a solar oven manufactured from MDF boards intended for the baking of foods such as pizza, cakes, breads, hamburgers and the like. They will be given the manufacturing processes and assembly of such an oven which has features of low cost manufacturing. The main feature of the proposed furnace and can be transported to any locations because it is seated on a device for carrying case / backpack. Tests will be conducted for the baking of various foods and their results will be compared with the various types of existing solar ovens shown by the literature. They will analyze the thermal and economic feasibility of such an oven that can provide socialization of the use of solar energy for poor communities and can become a source of generation of employment and income. The proposed solar oven baking has capacity for two foods and can be manufactured to allow multiple simultaneous baking of food.

Atitudes e conhecimento dos consumidores sobre os alimentos irradiados: um inquérito conduzido em Natal, Brasil

The aim of this study is to assess the attitudes and knowledge of consumers about irradiated foods. The study sample corresponded to 65.52% women and the mean age was 41.82 (SD: 14.33) years. Only 66.9% of respondents consumers consult the list of ingredients on the label of packaged foods, and 13.4% of them said they had detected the phrase “FOOD TREATED BY IRRADIATION PROCESS.” Furthermore, 86.6% considered that irradiation becomes unsafe food and thus 94.9% of those not consume these foods, as well as 29.6% of those who felt otherwise. Women had a score of attitude towards irradiated foods less favorable than men. The television was considered the most efficient means of communication to report on irradiated foods. We conclude that consumers of the city of Natal lack information about food irradiation and acceptance of these products depends on how the policies are directed to food security and health education, including through the use of sources of mass information dissemination. The information on the labels of irradiated foods is controversial, although sufficient instruments for detection of irradiated foods by these consumers.

Modificação do eletrodo AWS E7018 com adição de filmes finos externos de PVC e Al, para soldagem de aço C-Mn

This paper suggests modifications in coating of electrodes providing an alternative for execution of welding with low hydrogen electrode AWS E7018 without having to dry it, reducing thus the cost and time of manufacturing of high resistance welds. The welds in this research were developed with basic coated electrodes (hygroscopic) – SMAW process – externally painted with aluminum spray paint for high temperatures or wrapped with thin plastic films (PVC) and aluminum foil films used commonly for food protection. The basic premise is that establishing a barrier between the atmosphere and the electrode coating could reduce the effects of high hygroscopicity presented by coatings of low hydrogen, minimizing this way the main source of supply of hydrogen to the fusion pool during welding. It is also expected that the addition of new materials from the electrode coating to the fusion pool would induce metallurgical changes in the deposited metal and, as a consequence, modifications in its mechanical properties. This research dealt with measuring the dissolved hydrogen in the deposited metal after welding with modified electrodes, evaluating the influence of these changes in the produced microstructures and in the mechanical properties of the resulting weld, and comparing the obtained results with the standard welding procedures and with the recently developed waterproof electrodes. The results obtained in most samples welded with modified electrodes showed increased mechanical resistance and increased tenacity due to the increased percentage of acicular ferrite in metal deposited without significant elevation of hardness, when compared with the traditional welding with AWS E7018 electrode and with ELBRÁS BRH4R waterproof electrode. The diffusing hydrogen measured in the modified electrodes was kept inside the parameters defined by international codes.

Modificação do eletrodo AWS E7018 com adição de filmes finos externos de PVC e Al, para soldagem de aço C-Mn

This paper suggests modifications in coating of electrodes providing an alternative for execution of welding with low hydrogen electrode AWS E7018 without having to dry it, reducing thus the cost and time of manufacturing of high resistance welds. The welds in this research were developed with basic coated electrodes (hygroscopic) – SMAW process – externally painted with aluminum spray paint for high temperatures or wrapped with thin plastic films (PVC) and aluminum foil films used commonly for food protection. The basic premise is that establishing a barrier between the atmosphere and the electrode coating could reduce the effects of high hygroscopicity presented by coatings of low hydrogen, minimizing this way the main source of supply of hydrogen to the fusion pool during welding. It is also expected that the addition of new materials from the electrode coating to the fusion pool would induce metallurgical changes in the deposited metal and, as a consequence, modifications in its mechanical properties. This research dealt with measuring the dissolved hydrogen in the deposited metal after welding with modified electrodes, evaluating the influence of these changes in the produced microstructures and in the mechanical properties of the resulting weld, and comparing the obtained results with the standard welding procedures and with the recently developed waterproof electrodes. The results obtained in most samples welded with modified electrodes showed increased mechanical resistance and increased tenacity due to the increased percentage of acicular ferrite in metal deposited without significant elevation of hardness, when compared with the traditional welding with AWS E7018 electrode and with ELBRÁS BRH4R waterproof electrode. The diffusing hydrogen measured in the modified electrodes was kept inside the parameters defined by international codes.

Avaliação da Qualidade e Segurança Microbiológica de Hortofrutícolas

Frutas e vegetais frescos, embora sejam essenciais para uma dieta equilibrada e nutritiva, estão frequentemente associados a surtos de origem alimentar, pois este tipo de produto é muitas vezes consumidos cru, sem qualquer processamento térmico que elimine ou reduza para níveis aceitáveis a carga microbiana patogénica. Desta forma, e para que o consumo deste tipo de produtos continue a aumentar, torna-se importante aumentar o controlo em termos de segurança alimentar em todas as fases de produção. O presente trabalho de investigação teve por objetivos estudar a ocorrência de cinco microrganismos patogénicos: Salmonella sp.; Escherichia coli; Staplylococcus aureus; Listeria monocytogenes; HAV (vírus da Hepatite A), em framboesas e alface à venda no mercado português, otimizando uma técnica simples e rápida para deteção desses microrganismos nesses produtos. Também neste trabalho foi feito um estudo sobre os hábitos de consumo de produtos minimamente processados, framboesas e alface através de um inquérito por questionário. A escolha dos produtos e microrganismos a pesquisar teve por base um levantamento de quais as contaminações e os hortofrutícolas mais afetados nos últimos anos. A investigação iniciou-se com a pesquisa do HAV em framboesas e alface, onde após uma revisão bibliográfica, foram testados quatro protocolos distintos. No entanto devido à complexidade das técnicas para pesquisa de vírus em alimentos, à falta de meios e controlos para o desenvolvimento das respetivas técnicas, este objetivo foi abandonado. Numa segunda fase foi otimizado um método de deteção (PCR) para pesquisa das bactérias patogénicas, igualmente em framboesas e alface. Após otimização das condições de PCR, foram testados dois métodos de preparação da amostra: um com um passo de rebentamento de células baseado na fervura; e outro onde apenas se recolheu algum volume de cultura de pré-enriquecimento, tendo-se usado a mesma diretamente para a reação de PCR. Concluiu-se que apenas o primeiro método é eficiente, mas apenas para bactérias Gram-negativas (Salmonella sp. e E. coli) uma vez que estas possuem uma parede celular fina, capaz de ser destruída pela fervura, ao contrário das Gram-positivas (S. aureus e L. monocytogenes). Das amostras de framboesas e alface à venda no mercado português analisadas, concluiu-se que, apesar do método ainda necessitar de alguns ajustes, apenas a amostra de alface fresca parece não apresentar qualquer contaminação com Salmonella sp. e E. coli. Para S. aureus e L. monocytogenes não foi possível obter conclusões definitivas quanto à sua presença nas amostras analisadas, já que vários testes de confirmação deverão ser repetidos. Relativamente aos resultados obtidos acerca do inquérito de consumo, tem-se que dos 186 inquiridos, a grande maioria consome produtos hortofrutícolas minimamente processados 1-3 vezes/semana, tendo, a grande maioria, o hábito de os lavar com água antes do seu consumo, prática esta que é aconselhada. Quanto ao consumo de alface, a frequência aumenta para 3-5 vezes/semana, sendo esta adquirida maioritariamente inteira fresca e em superfícies comerciais. Por fim o consumo de framboesas ainda é escasso, pois a grande maioria dos inquiridos alega consumir este produto esporadicamente, sendo estas adquiridas embaladas inteiras frescas em superfícies comerciais.