955 resultados para Usinagem - Processos de fabricação


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The titanium and titanium alloys are widely used as biomaterial in biomedical device and so research have been developed aiming to improve and/or better to understand interaction biomaterial/biological environment. The process for manufacturing of this titanium implants usually involves a series of thermal and mechanical processes which have consequence on the final product. The heat treatments are usually used to obtain different properties for each application. In order to understand the influence of these treatments on the biological response of the surface, it was done, in this work, different heat treatments in titanium and analyzed their influence on the morphology, adhesion and proliferation of the pre-osteoblastic cells (MC3T3-E1). For such heat-treated titanium disks were characterized by optical microscopy, contact angle, surface energy, roughness, microhardness, X-ray diffraction and scanning through the techniques (BSE, EDS and EBSD). For the analysis of biological response were tested by MTT proliferation, adhesion by crystal violet and β1 integrin expression by flow cytometry. It was found that the presence of a microstructure very orderly, defined by a chemical attack, cells tend to stretch in the same direction of orientation of the material microstructure. When this order does not happen, the most important factor influencing cell proliferation is the residual stress, indicated by the hardness of the material. This way the disks with the highest level state of residual stress also showed increased cell proliferation

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The petrochemical industry has as objective obtain, from crude oil, some products with a higher commercial value and a bigger industrial utility for energy purposes. These industrial processes are complex, commonly operating with large production volume and in restricted operation conditions. The operation control in optimized and stable conditions is important to keep obtained products quality and the industrial plant safety. Currently, industrial network has been attained evidence when there is a need to make the process control in a distributed way. The Foundation Fieldbus protocol for industrial network, for its interoperability feature and its user interface organized in simple configuration blocks, has great notoriety among industrial automation network group. This present work puts together some benefits brought by industrial network technology to petrochemical industrial processes inherent complexity. For this, a dynamic reconfiguration system for intelligent strategies (artificial neural networks, for example) based on the protocol user application layer is proposed which might allow different applications use in a particular process, without operators intervention and with necessary guarantees for the proper plant functioning

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The oscillations presents in control loops can cause damages in petrochemical industry. Canceling, or even preventing such oscillations, would save up to large amount of dollars. Studies have identified that one of the causes of these oscillations are the nonlinearities present on industrial process actuators. This study has the objective to develop a methodology for removal of the harmful effects of nonlinearities. Will be proposed an parameter estimation method to Hammerstein model, whose nonlinearity is represented by dead-zone or backlash. The estimated parameters will be used to construct inverse models of compensation. A simulated level system was used as a test platform. The valve that controls inflow has a nonlinearity. Results and describing function analysis show an improvement on system response

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A pesquisa tem como objetivo desenvolver uma estrutura de controle preditivo neural, com o intuito de controlar um processo de pH, caracterizado por ser um sistema SISO (Single Input - Single Output). O controle de pH é um processo de grande importância na indústria petroquímica, onde se deseja manter constante o nível de acidez de um produto ou neutralizar o afluente de uma planta de tratamento de fluidos. O processo de controle de pH exige robustez do sistema de controle, pois este processo pode ter ganho estático e dinâmica nãolineares. O controlador preditivo neural envolve duas outras teorias para o seu desenvolvimento, a primeira referente ao controle preditivo e a outra a redes neurais artificiais (RNA s). Este controlador pode ser dividido em dois blocos, um responsável pela identificação e outro pelo o cálculo do sinal de controle. Para realizar a identificação neural é utilizada uma RNA com arquitetura feedforward multicamadas com aprendizagem baseada na metodologia da Propagação Retroativa do Erro (Error Back Propagation). A partir de dados de entrada e saída da planta é iniciado o treinamento offline da rede. Dessa forma, os pesos sinápticos são ajustados e a rede está apta para representar o sistema com a máxima precisão possível. O modelo neural gerado é usado para predizer as saídas futuras do sistema, com isso o otimizador calcula uma série de ações de controle, através da minimização de uma função objetivo quadrática, fazendo com que a saída do processo siga um sinal de referência desejado. Foram desenvolvidos dois aplicativos, ambos na plataforma Builder C++, o primeiro realiza a identificação, via redes neurais e o segundo é responsável pelo controle do processo. As ferramentas aqui implementadas e aplicadas são genéricas, ambas permitem a aplicação da estrutura de controle a qualquer novo processo

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In the last decades, the oil, gas and petrochemical industries have registered a series of huge accidents. Influenced by this context, companies have felt the necessity of engaging themselves in processes to protect the external environment, which can be understood as an ecological concern. In the particular case of the nuclear industry, sustainable education and training, which depend too much on the quality and applicability of the knowledge base, have been considered key points on the safely application of this energy source. As a consequence, this research was motivated by the use of the ontology concept as a tool to improve the knowledge management in a refinery, through the representation of a fuel gas sweetening plant, mixing many pieces of information associated with its normal operation mode. In terms of methodology, this research can be classified as an applied and descriptive research, where many pieces of information were analysed, classified and interpreted to create the ontology of a real plant. The DEA plant modeling was performed according to its process flow diagram, piping and instrumentation diagrams, descriptive documents of its normal operation mode, and the list of all the alarms associated to the instruments, which were complemented by a non-structured interview with a specialist in that plant operation. The ontology was verified by comparing its descriptive diagrams with the original plant documents and discussing with other members of the researchers group. All the concepts applied in this research can be expanded to represent other plants in the same refinery or even in other kind of industry. An ontology can be considered a knowledge base that, because of its formal representation nature, can be applied as one of the elements to develop tools to navigate through the plant, simulate its behavior, diagnose faults, among other possibilities

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Currently in the social sciences the question of self-identity and its meanings, absorb as a central objective aspects that concern analysis of an imaginary (re) constructed from processes of identity affirmation. Ethnic discourse in the consolidation of social boundaries (re) assemble a social policy apparatus able to claim their belongings concerning his ancestry, as well as the interpretation of the meanings given to their territory by any group. This dissertation work is the result of an ethnographic study undertaken with the residents of the Community Maloca, Vargas located in the neighborhood adjacent to the commercial center in Aracaju - SE. Since February 2007 the group is certified by FCP - Palmares Cultural Foundation as a lasting community, while it is part of a special gift for being an urban center, varying from the majority of that remaining Maroons in their contexts, outcrops and specific land rural. It focuses on the work process of territorial formation of the hut, and the arrival of their first actors, contextualizing the process of legitimation refers to the territory they live, as well as the various narratives that (re) construct the time he lived, the relations kinship, conflict, the process of self-affirmation as runaways and the relationship of belonging with their living space / living contained in the imaginary city of Aracaju. Attempts are made to the opportunity to understand the meanings that affirm their ethnicity, parallel group for the pursuit of effective policies and guarantee of constitutional rights in the urban context.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This thesis is defined as a reflection on the mechanisms of expression and insertion of the homo situs in the participatory governance in Mozambique. For a better understanding of this social fact, it was settled a periodization which covered the decline of colonialism at the time of the independence, which was proclaimed in June 1975, the civil war that lasted over 16 years and the period of the democratic State, further established. Therefore, we sought to understand the mechanisms and failures of the participation of the homo situs in local development projects that absorbed the needs and problems of these peasants, not mobilizing the skills and social competences of these communities. It would be essential for the homo situs a genuine democratic practice involving a political culture based on the social construction of the territories of the traditional man which was characterized by being procedural and historical, finding in participation its higher base. In this context, it would be desirable that the community development in Mozambique could contemplate and respect the choices of the homo situs. For this purpose, it would be fundamental the consistency between theory and practice, which builds and rebuilds, continually the competence of the peasants, facilitating the possibility of realization of their primordial aspirations. In the research, it became apparent that there is not a continuous process of participation of the rural communities, which appear as participants, only at the time of the implementation of the activities. Therefore, even having the participation of the communities expected by the law, with predictable moments of discussion and necessary conditions for that, the State failed to establish an ongoing process of democratic dialogue with traditional populations, as well as it failed to organize, properly, accurate informational bases to help solve the problems of rural areas. These facts have led to obstacles to the process of conquest of the human and civil rights of the traditional communities

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Parties are one of the most communicative languages, full of contents and symbolic meanings. The devotion to the saints is a kind of communication. In this thesis communicational processes, its languages and its flows are sought at the Saint Sebastian s party, at Alecrim neighborhood, in Natal/RN. The view is focused on the individuals and collective behaviors, in a dynamic which involves the saint s interlocutors at the party space, which supports the pre-novena, the novena and the procession. It tries to show through observation, ethnography and interviews the elements that composes the symbolic language present on the gestures, on the performances and bodies movements, on the clothing colors, as well as on what is said orally or in silence, on the spontaneous prayers or pre-elaborated ones, on the written messages that the devout addresses to the saint at the patron s festivity

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Given the great diversity of fishes, the Order Tetraodontiformes stands to show genetic and morphological characteristics enough singular. The fishes of this order have a compact DNA which favors molecular studies, as well as comparisons with more basal species. Model of genome evolution, there are still many gaps in knowledge about their chromosomal patterns and how evolutionary rearrangements influence the marked variation in DNA content of this order. In view of this, we present cytogenetic analyzes of the species Acanthostracion quadricornis (Ostraciidae), A. polygonius (Ostraciidae) Melichthys niger (Balistidae) Cantherhines macrocerus (Monacanthidae) and C. pullus (Monacanthidae), Lagocephalus laevigatus, Colomesus psittacus and Canthigaster figueiredoi (Tetraodontidae), to contribute with cytogenetic data for this group. The analysis was performed by C-banding, Ag-RONs, coloring with base-specific fluorochromes DAPI-CMA3, restriction enzymes AluI, EcoRI, TaqI, PstI and HinfI and in situ hybridization with probes for ribosomal DNA 18S and 5S. The heterochromatic ultrastructure of A. quadricornis and A. polygonius revealed a outstanding heterochromatin content, which may indicate that the accumulation or loss of extensive heterochromatin content could be responsible for large variations in genomic content displayed in different Tetraodontiformes families. The species Cantherhines macrocerus, C. pullus (Monacanthidae) and Melichthys niger (Balistidae) shows a huge karyotypic similarity both numerically and structural. L. laevigatus showed similar cytogenetic features (2n = 44 and single RONs) to the species of the genus Takifugu, which reinforces the idea of their phylogenetic relationships. C. psittacus presented the highest diploid number described for the family (2n = 56) and large amount of HC, features that related with its sister family Diodontidae. Cytogenetic analysis in C. figueiredoi revealed heterochromatic polymorphisms, RONs multiple and Bs chromosomes. These events are rare in marine fishes, and are possibly associated with the strong restructuring and genomic reduction that this family has been suffered. These features, plus the morphological and molecular data suggests that these species share the same ancestral branch, with a possible monophyletic origin. In this study, new contributions to the knowledge of evolutionary patterns facing by Tetraodontiformes are provided and discussed under cytotaxonomyc, genomic and evolutionary perspectives.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The present work had as principal objective to analyze the, 9th grade students understanding about the solutions of an equation of the 2° degree, using geometric processes of the History of the Mathematics. To do so, the research had as base the elaboration and application of a group of teaching activities, based on Jean Piaget's construtivism. The research consisted of a methodological intervention, that has as subjects the students of a group of 9th grade of the State School José Martins de Vasconcelos, located in the municipal district of Mossoró, Rio Grande do Norte. The intervention was divided in three stages: application of an initial evaluation; development of activities‟ module with emphasis in constructive teaching; and the application of the final evaluation. The data presented in the initial evaluation revealed a low level of the students' understanding with relationship to the calculation of areas of rectangles, resolution of equations of the 1st and 2nd degrees, and they were to subsidize the elaboration of the teaching module. The data collected in the initial evaluation were commented and presented under descriptive statistics form. The results of the final evaluation were analyzed under the qualitative point of view, based on Richard Skemp's theory on the understanding of mathematical concepts. The general results showed a qualitative increase with relationship to the students' understanding on the mathematical concepts approached in the intervention. Such results indicate that a methodology using the previous student‟s knowledge and the development of teaching activities, learning in the construtivist theory, make possible an understanding on the part of the students concerning the thematic proposal

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study focuses on processes of learning and professional development experienced by elementary school teachers who have students with special educational needs in their classrooms. Cases and case methods can be used as methodological resource to articulate the continued training of teachers in an inclusive perspective. This research-intervention adopted a constructive-collaborative model for continued teachers formation. The main objective was to investigate the possible contributions of teaching cases, while investigative and formative strategies, for the processes of learning and professional development of teachers who work in the regular school. The data were collected by means of analytical activities, drafting collective discussion and teaching cases, having eight teachers as participants in a regular public school, located in the municipality of Natal/RN, Brasil. The theoretical reference covers the inclusive education, teaching learning, teachers professional development, the knowledge base for teaching and teaching cases as a resource for continued teachers formation in an inclusive perspective. The results indicated that teaching cases allowed description and analysis of educational practices developed by regular education teachers and adoption of reflective processes about situations reported and on their own pedagogical actuation, achieving indications of changes. It also indicates the contribution of cases for the clarification, systematization and extension of professional knowledge about inclusive education process as well as for involvement by the teachers of the study in a pedagogical thinking process. The lessons learned are related mainly to own role as teachers of regular education, to the role of professional support and specialized institutions faced to school inclusion. The analyses showed the methodological option was suitable to develop a schoolcentric training process, allowing teachers to seek in their actual environment alternatives for construction of a new logic of teaching that encloses diversity. The conclusion is that the cases, while bringing educational situations closer to the reality experienced by teachers in their daily professional role, causes relevant improvement on teachers education, because it offers training in conjunction with the experience and knowledge that teachers already have

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study focuses on processes of learning and professional development experienced by elementary school teachers who have students with special educational needs in their classrooms. Cases and case methods can be used as methodological resource to articulate the continued training of teachers in an inclusive perspective. This research-intervention adopted a constructive-collaborative model for continued teachers formation. The main objective was to investigate the possible contributions of teaching cases, while investigative and formative strategies, for the processes of learning and professional development of teachers who work in the regular school. The data were collected by means of analytical activities, drafting collective discussion and teaching cases, having eight teachers as participants in a regular public school, located in the municipality of Natal/RN, Brasil. The theoretical reference covers the inclusive education, teaching learning, teachers professional development, the knowledge base for teaching and teaching cases as a resource for continued teachers formation in an inclusive perspective. The results indicated that teaching cases allowed description and analysis of educational practices developed by regular education teachers and adoption of reflective processes about situations reported and on their own pedagogical actuation, achieving indications of changes. It also indicates the contribution of cases for the clarification, systematization and extension of professional knowledge about inclusive education process as well as for involvement by the teachers of the study in a pedagogical thinking process. The lessons learned are related mainly to own role as teachers of regular education, to the role of professional support and specialized institutions faced to school inclusion. The analyses showed the methodological option was suitable to develop a schoolcentric training process, allowing teachers to seek in their actual environment alternatives for construction of a new logic of teaching that encloses diversity. The conclusion is that the cases, while bringing educational situations closer to the reality experienced by teachers in their daily professional role, causes relevant improvement on teachers education, because it offers training in conjunction with the experience and knowledge that teachers already have

Relevância:

20.00% 20.00%

Publicador:

Resumo:

La relation entre l`ignorance, l`apprentissage et de la création composent un décor provocant pour nous faire réfléchir sur l`éducation et la science. Pour éclaircir cette réflexion, nous démarrons sur les propositions de Ilya Prigogine (1986), pour qui l`art est une métaphore qui représente la science au XXe siècle, les idées d`Edgar Morin (2004), en soulignant la contribution fondamentale de l`art à l`état humain, et Maurice Merleau- Ponty (1980), qui crédite à l`art la possibilité d`un nouveau regard sur le monde, un regard sensible, esthétique. Ayant par référence la présence de ces arguments, nous réaffirmons la thèse de que l`art peut présenter des métaphores pour considérer la science, l`éducation et la condition humaine sur des bases complexes et transdisciplinaires. Nous nous concentrons sur des catégories particulières de la déformation et de la répétition. La première est considérée comme un désordre nécessaire au corps, à la science et à l`éducation, des lieux de métamorphose constante, d`après les principes de la complexité. La seconde est appréciée comme un opérateur sans lequel la variation, l`écart, le nouveau et l`invention ne peuvent pas émerger. Nos métaphores ressortent des travaux esthétiques de deux artistes de renom: Pina Bausch et Hans Bellmer, les délinquants qui certainement se rebellent contre la trivialité dans l`art et la vie. Ils exploitent des rêves, des démonstrations affectueuses impertinentes, esthétiques inaugurales, antiparadigmatiques et audacieuses. En un mot, ils incarnent ce qu`on appelle une pensée complexe. Nous comprenons que les deux artistes déclenchent des dispositifs qui dialoguent avec le manifeste de Merleau-Ponty lorsque l`on cherche dans l "aisthesis" la possibilité d`une production naturelle qui est en elle-même, créative. Ayant comme horizon cette puissance créatrice nous concentrons notre regard sur les anagrammes du corps proposés par Bellmer et sur la répétition exprimée par Pina Bausch. La déformation et la répétition sont des étapes embryonnaires de la création

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The concrete for centuries constituted an essential structural element in the construction industry due to its relative ease of forming, before the weather durability, low cost, its lower maintenance compared to other materials such as steel. However, when the concrete is exposed to high temperatures tends to lose its mechanical characteristics, and may even result in loss of section, which undermines the stability and mechanical strength of structural elements. The pathologies resulting from exposure to elevated temperatures ranging from cracks, pops up chipping explosives (spalling). Recently, the technology of concrete is closely related to the study of its microstructure. The use of fibers added to concrete has been revealed as a solution to increase the mechanical strength of the concrete, it acts directly on the distribution of efforts to act in the play within the microstructure. In this work we used recycled PET fibers embedded in concrete with 15x2mm fck = 30MPa, water/cement ratio of 0.46, in works made for verification of mechanical strength of this mixture submitted to high temperature. The specimens of concrete with addition of PET fibers were tested after exposure to temperatures: ambient (30ºC), 100°C, 200°C, 300°C, 400°C, 600°C and 900°C. It was found that the concrete loses significant strength when exposed to temperatures above 300°C, however the use of fiber PET may delay the risk of collapse of structures for the formation of a network of channels that facilitate the escape of vapor 'water, reducing the pore pressure inside the structural element