Estudo sobre o efeito dos parâmetros de processamento dos pós e sinterização do aço inox 316l reforçado com NbC

This masther dissertation presents a contribution to the study of 316L stainless steel sintering aiming to study their behavior in the milling process and the effect of isotherm temperature on the microstructure and mechanical properties. The 316L stainless steel is a widely used alloy for their high corrosion resistance property. However its application is limited by the low wear resistance consequence of its low hardness. In previous work we analyzed the effect of sintering additives as NbC and TaC. This study aims at deepening the understanding of sintering, analyzing the effect of grinding on particle size and microstructure and the effect of heating rate and soaking time on the sintered microstructure and on their microhardness. Were milled 316L powders with NbC at 1, 5 and 24 hours respectively. Particulates were characterized by SEM and . Cylindrical samples height and diameter of 5.0 mm were compacted at 700 MPa. The sintering conditions were: heating rate 5, 10 and 15◦C/min, temperature 1000, 1100, 1200, 1290 and 1300◦C, and soaking times of 30 and 60min. The cooling rate was maintained at 25◦C/min. All samples were sintered in a vacuum furnace. The sintered microstructure were characterized by optical and electron microscopy as well as density and microhardness. It was observed that the milling process has an influence on sintering, as well as temperature. The major effect was caused by firing temperature, followed by the grinding and heating rate. In this case, the highest rates correspond to higher sintering.

Estudo do efeito da adição da escória de aciaria no processamento e propriedades finais de telhas cerâmicas

This research presents an overview of the addition steelwork dust of ceramic shingles in order to contribute to the utilization use of such residue. The ceramic industry perspective in the Brazilian State of Piauí is quite promising. Unlike other productive sectors, the ceramic industry uses basically natural raw materials. Its final products are, in short, the result of transforming clay compounds. These raw materials are composed primarily of aluminum oxide, silicon, iron, sodium, magnesium, end calcium, among others. It was verified that steelwork dust is composed primarily of these same oxides, so that its incorporation in to structural ceramics is a very reasonable idea. Both clay and steelwork powder were characterized by AG, XRF, XRD, TGA and DTA. In addition, steelwork dust samples containing (0%, 5%, 10%, 15%, 20% and 25%) were extruded and burned at 800°C, 850°C, 900°C and 950°C. Then t echnological tests of linear shrinkage, water uptake, apparent porosity, apparent density and flexural strengthwere carried at. The results showed the possibility of using steelwork powder in ceramic shingles until 15% significant improvement in physical and mechanical properties. This behavior shows the possibility of burning at temperatures lower than 850ºC, thus promoting a product final cost reduction

Processamento e caracterização de compósitos Poli(METACRILATO DE METILA)/Sílica (PMMA/SiO2)

Currently the search for new materials with properties suitable for specific applications has increased the number of researches that aim to address market needs. The poly (methyl methacrylate) (PMMA) is one of the most important polymers of the family of polyacrylates and polymethacrylates, especially for its unique optical properties and weathering resistance, and exceptional hardness and gloss. The development of polymer composites by the addition of inorganic fillers to the PMMA matrix increases the potential use of this polymer in various fields of application. The most commonly used inorganic fillers are particles of silica (SiO2), modified clays, graphite and carbon nanotubes. The main objective of this work is the development of PMMA/SiO2 composites at different concentrations of SiO2, for new applications as engineering plastics. The composites were produced by extrusion of tubular film, and obtained via solution for application to commercial PMMA plates, and also by injection molding, for improved the abrasion and scratch resistance of PMMA without compromising transparency. The effects of the addition of silica particles in the polymer matrix properties were evaluated by the maximum tensile strength, hardness, abrasion and scratch resistance, in addition to preliminary characterization by torque rheometry and melt flow rate. The results indicated that it is possible to use silica particles in a PMMA matrix, and a higher silica concentration produced an increase of the abrasion and scratch resistance, hardness, and reduced tensile strength

Processamento e caracterização da blenda poli (metacrilato de metila) (PMMA) elastomerico e poli (tereftalato de etileno) (PET) pós-consumo

This work studied the immiscible blend of elastomeric poly(methyl methacrylate) (PMMA) with poly(ethylene terephthalate) (PET) bottle grade with and without the use of compatibilizer agent, poly(methyl methacrylate-co-glycidyl methacrylate - co-ethyl acrylate) (MGE). The characterizations of torque rheometry, melt flow index measurement (MFI), measuring the density and the degree of cristallinity by pycnometry, tensile testing, method of work essential fracture (EWF), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were performed in pure polymer and blends PMMA/PET. The rheological results showed evidence of signs of chemical reaction between the epoxy group MGE with the end groups of the PET chains and also to the elastomeric phase of PMMA. The increase in the concentration of PET reduced torque and adding MGE increased the torque of the blend of PMMA/PET. The results of the MFI also show that elastomeric PMMA showed lower flow and thus higher viscosity than PET. In the results of picnometry observed that increasing the percentage of PET resulted in an increase in density and degree crystallinity of the blends PMMA/PET. The tensile test showed that increasing the percentage of PET resulted in an increase in ultimate strength and elastic modulus and decrease in elongation at break. However, in the phase inversion, where the blend showed evidence of a co-continuous morphology and also, with 30% PET dispersed phase and compatibilized with 5% MGE, there were significant results elongation at break compared to elastomeric PMMA. The applicability of the method of essential work of fracture was shown to be possible for most formulations. And it was observed that with increasing elastomeric PMMA in the formulations of the blends there was an improvement in specific amounts of essential work of fracture (We) and a decrease in the values of specific non-essential work of fracture (βWp)

Estudo de adsorvente obtido de terras diatomáceas para remoção de metais pesados em águas produzidas: processamento, caracterização e dinâmica em leito fixo

The acceleration of industrial growth in recent decades on all continents aroused the interest of the companies to counter the impacts produced on the environment, spurred primarily by major disasters in the petroleum industry. In this context, the water produced is responsible for the largest volume of effluent from the production and extraction of oil and natural gas. This effluent has in its composition some critical components such as inorganic salts, heavy metals (Fe, Cu, Zn, Pb, Cd, ), presence of oil and chemicals added in the various production processes. In response to impact, have been triggered by research alternative adsorbent materials for water treatment and water produced, in order to removing oils and acids and heavy metals. Many surveys of diatomaceous earth (diatomite) in Brazil involve studies on the physico-chemical, mineral deposits, extraction, processing and applications. The official estimated Jazi are around 2.5 million tonnes, the main located in the states of Bahia (44%) and Rio Grande do Norte (37,4%). Moreover, these two states appear as large offshore producers, earning a prominent role in research of adsorbents such as diatomite for treatment of water produced. Its main applications are as an agent of filtration, adsorption of oils and greases, industrial load and thermal insulator. The objective of this work was the processing and characterization of diatomite diatomaceous earth obtained from the municipality of Macaíba-RN (known locally as tabatinga) as a low cost regenerative adsorbent for removal of heavy metals in the application of water produced treatment. In this work we adopted a methodology for batch processing, practiced by small businesses located in producing regions of Brazil. The characterization was made by X-ray diffraction (XRD), scanning electron microscopy (SEM) and specific surface area (BET). Research conducted showed that the improvement process used was effective for small volume production of diatomite concentrated. The diatomite obtained was treated by calcination at temperature of 900 oC for 2 hours, with and without fluxing Na2CO3 (4%), according to optimal results in the literature. Column adsorption experiments were conducted to percolation of the in nature, calcined and calcined fluxing diatomites. Effluent was used as a saline solution containing ions of Cu, Zn, Na, Ca and Mg simulating the composition of produced waters in the state of Rio Grande do Norte, Brazil. The breakthrough curves for simultaneous removal of copper ions and zinc as a result, 84.3% for calcined diatomite and diatomite with 97.3 % for fluxing. The calcined fluxing diatomite was more efficient permeability through the bed and removal of copper and zinc ions. The fresh diatomite had trouble with the permeability through the bed under the conditions tested, compared with the other obtained diatomite. The results are presented as promising for application in the petroleum industry

Processamento Inteligente de Sinais de Pressão e Temperatura Adquiridos Através de Sensores Permanentes em Poços de Petróleo

Originally aimed at operational objectives, the continuous measurement of well bottomhole pressure and temperature, recorded by permanent downhole gauges (PDG), finds vast applicability in reservoir management. It contributes for the monitoring of well performance and makes it possible to estimate reservoir parameters on the long term. However, notwithstanding its unquestionable value, data from PDG is characterized by a large noise content. Moreover, the presence of outliers within valid signal measurements seems to be a major problem as well. In this work, the initial treatment of PDG signals is addressed, based on curve smoothing, self-organizing maps and the discrete wavelet transform. Additionally, a system based on the coupling of fuzzy clustering with feed-forward neural networks is proposed for transient detection. The obtained results were considered quite satisfactory for offshore wells and matched real requisites for utilization

Implementação do algoritmo (RTM) para processamento sísmico em arquiteturas não convencionais

With the growth of energy consumption worldwide, conventional reservoirs, the reservoirs called "easy exploration and production" are not meeting the global energy demand. This has led many researchers to develop projects that will address these needs, companies in the oil sector has invested in techniques that helping in locating and drilling wells. One of the techniques employed in oil exploration process is the reverse time migration (RTM), in English, Reverse Time Migration, which is a method of seismic imaging that produces excellent image of the subsurface. It is algorithm based in calculation on the wave equation. RTM is considered one of the most advanced seismic imaging techniques. The economic value of the oil reserves that require RTM to be localized is very high, this means that the development of these algorithms becomes a competitive differentiator for companies seismic processing. But, it requires great computational power, that it still somehow harms its practical success. The objective of this work is to explore the implementation of this algorithm in unconventional architectures, specifically GPUs using the CUDA by making an analysis of the difficulties in developing the same, as well as the performance of the algorithm in the sequential and parallel version

Defumação da tilápia do Nilo (Oreochromis niloticus) inteira eviscerada e filé: aspectos referentes às características organolépticas, composição centesimal e perdas ocorridas no processamento

O objetivo do experimento foi avaliar o efeito da defumação da tilápia do Nilo (Oreochromis niloticus) inteira eviscerada e filé sobre as características organolépticas (aparência, aroma, cor, sabor, textura, teor de sal e aceitação geral), a porcentagem de perda de peso (PP) e composição centesimal. Foram comparados FP1 (peixe inteiro eviscerado, 5 horas de fumaça) e FP2 (filé, 4 horas de fumaça). Os peixes foram descamados, eviscerados, para obtenção de FP1 ou filetados por uma única pessoa, para obtenção de FP2, e então submetidos à salmouragem úmida (30%) e à defumação. O rendimento médio para FP1 e FP2 foi de 63,98 e 27,11%, respectivamente. O valor médio para porcentagem de perda de peso ocorrida na defumação para o filé (31,33%) foi superior ao peixe inteiro (27,04%). A análise sensorial revelou que o peixe inteiro teve melhor aceitação quanto ao sabor e teor de sal e não diferiu do filé quanto ao aroma, cor e textura. O processo de defumação reduziu o conteúdo de umidade e proporcionou aumento nos teores de proteína bruta, lipídios e cinzas. As perdas foram maiores para o filé, que apresentou maior teor de proteína bruta e menor teor de lipídios comparado ao peixe inteiro. Verificou-se também que o sabor do filé pode ser melhorado em função de uma correção na salmouragem.

Poéticas de um saber brincar: a vez e a voz do fandango

The present thesis aims to get to know and to analyze the elements which make up the poetical performance of the Fandango from Canguaretama confirming/corroborating an eminently theatrical model. It still highlights the producers´ history, its asset production and its insertion in community where we had contact with two other types of performances: the daily and the ritualistic. Such actions both combine and present different meanings and objectives, promoting distinct readings and experiences. Looking at these three ways of performances poetic, daily, and ritual enabled to go deeper in cultural aspects of the studied community and, thus, check over what is going on in these events, how they accord with and conceive a popular performance context. The research could substantiate the existence of a theatrical model whose performance by means of the voice and active presence of playful bodies, implied in getting to know the consolidation of a cultural patrimony which reveals us the past, but, especially, the present, its people and its place

As zonas de processamento de exportação como instrumento de desenvolvimento e redução das desigualdades regionais

The existence of inequalities among the Brazilian regions is an indeed fact along the country s history. Before this reality the constitutional legislator inserted into the Federal Constitution of 1988, as a purpose of the Federative Republic of Brazil, the reduction of regional inequalities. The development has also been included as a purpose from the State, because there is an straight relation with the reduction of regional inequalities. In both situations is searched the improvement of people s living conditions. . In pursuit of this achievement, the State must implement public policy, and, for this to happen, it needs the ingress of income inside of the public coffers and support of economic agents, therefore the importance of constitucionalization of the economic policy. The 1988 s Constitution adopted a rational capitalism regime consentaneous with current legal and social conceptions, that s why it enabled the State s intervention into economy to correct the so-called market failures or to make the established objectives fulfilled. About this last one, the intervention may happen by induction through the adoption of regulatory Standards of incentive or disincentive of economic activity. Among the possible inductive ways there are the tax assessments that aim to stimulate the economic agents behavior in view of finding that the development doesn t occur with the same intensity in all of the country s regions. Inside this context there are the Export Processing Zones (EPZs) which are special areas with different customs regime by the granting of benefits to the companies that are installed there. The EPZs have been used, by several countries, in order to develop certain regions, and economic indicators show that they promoted economic and social changes in the places where they are installed, especially because, by attracting companies, they provide job creation, industrialization and increased exports. In Brazil, they can contribute decisively to overcome major obstacles or decrease the attraction of economic agents and economic development of the country. In the case of an instrument known to be effective to achieve the goals established by the Constitution, it is duty of the Executive to push for the law that governs this customs regime is effectively applied. If the Executive doesn t fulfill this duty, incurs into unjustifiable omission, correction likely by the Judiciary, whose mission is to prevent acts or omissions contrary to constitutional order

Processamento mínimo em goiabas 'Paluma' e 'Pedro Sato': 2. Avaliação química, sensorial e microbiológica

Foram utilizados frutos de goiabeiras das cultivares Pedro Sato e Paluma, provenientes de pomar comercial, no estádio de maturação de vez, correspondente à coloração verde-mate e considerados ótimo para o consumo. Os frutos foram inicialmente imersos em solução de hipoclorito de sódio (150mg de cloro.L-1) por 5 minutos, para desinfecção superficial. Pessoas treinadas, utilizando proteção adequada e equipamentos desinfetados descascaram os frutos, cortaram-nos longitudinalmente ao meio e eliminaram a polpa com as sementes, em ambiente a 12&deg;C. Após enxágüe com água clorada (20mg de cloro.L-1) foram embalados em contentores de tereftalato de polietileno (PET) com tampa. Estas unidades foram armazenadas a 3&deg;C por 10 dias. Foram realizadas análises microbiológicas ao longo do período. Determinaram-se quimicamente os conteúdos de lignina, ácido ascórbico, acidez total titulável, sólidos solúveis totais e porcentagem de solubilização das pectinas, bem como as variáveis sensoriais de textura, sabor e preferência. A textura tornou-se mais frágil e os conteúdos de ácido ascórbico se reduziram, ao longo do período de armazenamento, nos produtos de ambas as cultivares. Durante este período houve aumento no conteúdo de lignina e manutenção dos conteúdos de sólidos solúveis totais (SST), acidez total titulável (ATT) e da relação SST/ATT. O produto da cultivar Pedro Sato apresentou menor perda de textura que o da 'Paluma', sendo considerado pelos provadores como o mais saboroso e, portanto, o mais preferido. Devido aos cuidados higiênicos tomados durante o processamento o produto apresentou baixa contagem microbiana (< 10³ UFC.g-1), em todas as avaliações efetuadas.

Processamento mínimo de mamão 'formosa'

Este trabalho foi conduzido para verificar o efeito do tamanho do corte, 2,5 x 2,5cm (corte 1) e 2,5 x 5,0cm (corte 2), e da temperatura de armazenamento (3, 6 e 9ºC), na velocidade da modificação da atmosfera ambiente e nas características químicas de mamões do grupo `Formosa' minimamente processados e embalados em copos plásticos (500ml). A concentração de CO2 no interior destes copos aumentou 2 a 3 vezes, durante as primeiras 6 horas após o corte, para depois diminuir e se estabilizar. Esta concentração aumentou com o aumento da temperatura de armazenamento. A umidade dos pedaços diminuiu consideravelmente nos dois primeiros dias, e a temperatura que melhor conservou a umidade foi a de 6ºC. A acidez total titulável foi menor no corte 2, com as maiores reduções a 6 e 9oC. Os teores de sólidos solúveis totais não variaram entre os tratamentos, e os cuidados higiênicos adotados durante o processamento permitiram a obtenção de produtos com baixa contagem microbiana, 10³UFC.g-1 nos pedaços armazenados a 9ºC após sete dias, e com boa manutenção da qualidade sensorial das mesmas. Estes resultados permitem indicar o mamão `Formosa' para a produção de produtos minimamente processados, na forma de pedaços, com conservação refrigerada (3 e 6ºC ) por um período de 7 dias.

Gritos de silêncio: na voz dos familiares cuidadores de portadores da doença de Alzheimer

This work is an investigation related to issues of those who take home care of people who suffer from Alzheimer disease (AD). Thus, it is justified by the need to acknowledge how these relatives perform this task and in which ways they do this. The study has is analytical and qualitative methodology with the use of a thematic oral history approach. The subjects of the research were nine relatives of those who suffer from AD that participate in the home care group in the Candelária neighborhood in the city of Natal in Rio Grande do Norte-Brazil. The data was collected using a semi-structured questionnaire and interview that was booked in advance and had full support from the care takers. After information collection, three thematic axles were defined. After this procedure, three analisys subcategories were also defined. The first thematic axle emphasizes the so called movement of rite of passage, when the relative becomes a care taker of a person with AD. The second category deals with the care takers strategies, either related to their own behalf or on their relative. It is possible to infer that amongst other forms of help, the care taker needs to rely on a support network, such as health services, groups composed by multiprofessionals that enable better articulation between family and collaborators. The dimension related to faith and spirituality was also observed and pointed out as an important aspect in the emotional support process for these relatives. In the third axle the perspectives of struggle, conquests of the right to health and life quality of those who suffer from AD as well as their relatives was observed. These also deal with dreams and hope

Processamento mínimo de uvas de mesa sem semente

O trabalho teve como objetivo avaliar os aspectos qualitativos de uvas de mesa apirênicas (sem sementes) quando submetidas ao processamento mínimo e armazenadas sob refrigeração. Para tanto, foram utilizadas uvas da cultivar BRS Morena e da Seleção Avançada nº 8, produzidas na Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Uva e Vinho/Estação Experimental de Viticultura Tropical (da Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) de Jales). Os cachos, depois de higienizados, imersos em água clorada a 300 mg de cloro.L-1 por 5 min., foram mantidos em câmara fria, a 12ºC, por 12 h. Pessoas treinadas e com proteção adequada procederam à degrana dos cachos e ao posterior enxágüe das bagas com água clorada (20 mg.L-1) a 12ºC. Depois de escorrido o excesso de água, as bagas foram acondicionadas em bandejas de tereftalato de polietileno (PET) transparente com tampa e com capacidade para 500 mL. Cada unidade, contendo 200 g de bagas, foi armazenada a 2,5 ± 1ºC e 88% UR por até 36 dias. Avaliaram-se a perda de massa fresca, a evolução da aparência, a coloração e os teores de sólidos solúveis totais (SST), e de acidez titulável (AT). Nas condições do experimento, os produtos minimamente processados da cv. BRS Morena e da Seleção 8 apresentaram baixa perda acumulada de massa fresca (0,16%). O produto da cv. Morena apresentou-se mais escuro (L = 25,04) e mais arroxeado (h&deg; = 332,88) que o da Seleção 8 (L = 29,86 e h&deg; = 345,11), propiciando-lhe melhor qualidade visual. O suco da 'BRS Morena' apresentou maiores teores de SST (22,17 &deg;Brix) e menores para a AT (0,56 %), o que resultou em uma relação SST/AT maior e melhor (39,76) que o da Seleção 8 (18,81). A cv. BRS Morena também apresentou boa manutenção da aparência e, portanto, da qualidade comercial, por 33 dias a 2,5&deg;C, superior ao obtido para a Seleção 8 (24 dias).

Adoção de tecnologias móveis em empresas do Rio Grande do Norte, Pernambuco e Ceará

One of the best examples of the Information and Communication Technology (ICT) evolutions is on the high capability of storing and processing data into smaller devices, creating a new business condition, the mobility . This mobility in a deeper analysis proposes a business remodeling in many different areas (business segmentations), through the Internet anywhere at any time, allowing managers and researchers to think again their actual models that work nowadays in companies and public institutions, modifying the way internal and external clients can be attended. This thesis analyzes issues on mobile business adoption, technological evolutions and the impacts caused by this new reality the access to information anywhere at any time . This research is exploratory and shows a compilation of similar papers and thesis describing how was conducted the survey within 50 companies in the states of Rio Grande do Norte, Pernambuco and Ceará. The statistics analysis showed the different level of mobile technology usage from simple voice communications to wide band data transmission. The analysis pointed that canonic correlation was the most effective type of analysis to describe the relations among all groups of variables showing which of them are relevant, or not, for mobile technology adoption