Efeitos da embalagem em ar, sob vácuo e em atmosfera modificada sobre a qualidade de filetes de peixe-porco Balistes capriscus

Dissertação de mest, Tecnologia de Alimentos, Instituto Superior de Engenharia, Univ. do Algarve, 2013

Desordem ou vácuo institucional?: uma análise dos discursos presentes na educação superior peruana

This thesis is about change, discontinuity, instability. The theoretical perspective used to analyses the changing process was Institutional Theory, which argues that institutions has a long-term time. The institutional change has always be seen as a structural process and a incremental one, but this research aimed rescue the dynamic side of institutional change, understanding that as a result of deinstitutionalization and institutionalization processes. In order to understand the deinstitutionalization and institutionalization processes, we try to understand the concepts of interactive and iterative. So, it was possible understand that these process are interdependent and has to be understood as both side of institutional change. Nevertheless, it couldn¿t have an institutional vacuum, but a hybrid order or plural one, where a set of institutional forces would find its legitimacy. The Discourses Analysis supports this research, which was developed in Peru. A group of University professors was interviewed and we noticed that there are a lot of practices that act as micro institutional rules. In that way, we can admit that there is no vacuum, but a plural institutional order.

Pirólise térmica e catalítica de resíduos de vácuo gerados no refino de petróleo

In this study, was used a very promising technique called of pyrolysis, which can be used for obtaining products with higher added value. From oils and residues, since the contribution of heavier oils and residues has intensified to the world refining industry, due to the growing demand for fuel, for example, liquid hydrocarbons in the range of gasoline and diesel. The catalytic pyrolysis of vacuum residues was performed with the use of a mesoporous material belonging the M41S family, which was discovered in the early 90s by researchers Mobil Oil Corporation, allowing new perspectives in the field of catalysis. One of the most important members of this family is the MCM-41, which has a hexagonal arrangement of mesopores with pore diameters between 2 and 10 nm and a high specific surface area, making it very promising for use as a catalyst in petroleum refining for catalytic cracking, and their mesopores facilitate the access of large hydrocarbon molecules. The addition of aluminum in the structure of MCM-41 increases the acidity of the material, making it more positive for application in the petrochemical industry. The mesoporous material of the type Al-MCM41 (ratio Si / Al = 50) was synthesized by hydrothermal method starting from the silica gel, NaOH and distilled water added to the gel pseudobohemita synthesis. Driver was used as structural CTMABr. Removal of organic driver (CTMABr) was observed by TG / DTG and FTIR, but this material was characterized by XRD, which was observed the formation of the main peaks characteristic of mesoporous materials. The analysis of adsorption / desorption of nitrogen this material textural parameters were determined. The vacuum residues (VR's) that are products of the bottom of the vacuum distillation tower used in this study are different from oil fields (regions of Ceará and Rio de Janeiro). Previously characterized by various techniques such as FTIR, viscosity, density, SARA, elemental analysis and thermogravimetry, which was performed by thermal and catalytic degradation of vacuum residues. The effect of AlMCM-41 was satisfactory, since promoted a decrease in certain ranges of temperature required in the process of conversion of hydrocarbons, but also promoted a decrease in energy required in the process. Thus enabling lower costs related to energy expenditure from degradation during processing of the waste

Tratamento de fístulas enterocutâneas através de sistema a vácuo com alta pressão e dieta oral normal

Enterocutaneous fistulas are associated with prolonged hospital stay, high morbidity/mortality, and increase in hospital costs. This study aims to describe the use of a vacuum system and normal oral diet in dealing with this problem. Methods: Seventy-four consecutive patients with recent and defined external postoperative fistulas were analyzed. Abdominal imaging was used to exclude abscess and distal obstruction. The fistula tract was sealed with Foley catheter, connected to a negative pressure flask, changed daily for 5, 10 or 15 days, as necessary. Normal oral diet was permitted. Results: No patient died. Serum albumin and transferrin showed significantly higher levels at the end of treatment than at the beginning. The moderate and low-output fistulas had the best results (97% closed). Forty-eight (65%) fistulas closed after five days, 16(22%) after 10 days and 4(5%) after 15 days. Treatment failed in 6(8%) patients, who subsequently underwent surgery. Only one patient with low-output did not close her fistula. The cost of the treatment was US$ 41.75/day and it was considered cost effective. Conclusions: The vacuum system demonstrated good results in the treatment of fistulas. It included simplicity, low cost, short hospital stay, absence of skin breakdown, normal eating, good nutrition and activity patterns

Ensinando sobre a natureza da ciência: uma abordagem explícita e contextualizada a partir da história do vácuo

In last decades, the importance of including the contents of the Nature of Science (NOS) in Science Education has been emphasized. Several studies have focused on investigating the conceptions of NOS, supported by students and teachers, as well as design, implement and evaluate proposals that aim to provide a reflection on this theme in the educational context. Considering the complexity of such content, studies indicate the need for explicit and contextualized approaches and the History of Science (HS) is one of the possible paths to this inclusion. We started from the premise that, through a historical study, that aims to discuss the meaning and the basis of our "beliefs", we can know the process of building on what we "believe" and better understand its meaning. This thesis is part of this perspective, proposing to explore the History of the Vacuum, a themed high didactic potential still little used, in order to collaborate with the teaching content of NOS. We present actions on different fronts that originated three products in the context of this research. On the first front, we insert the research and production of instructional materials (three historical texts) to subsidize people interested in the implementation of HPS for educational context through this material. The relevance of this front is justified by the existence of gaps with regard to the production of such material for the context of teacher training. However, we consider that the preparation of instructional material of good quality and accessible does not guarantee that these resources will be used, if they will not be accompanied by discussions in teacher training, on how to use them, contexts and obstacles to be faced. The second part presented refers to the organization and implementation of a workshop for undergraduate students in physics and physics teachers, considering the instrumentalization of these individuals to the preparation and use of teaching strategies to approach aspects of NOS through episodes of History of the Vacuum, as well as the preparation of the text orientation for people interested in implementing the instructional material for secondary education. This guidance text contemplates the difficulties anticipated by the literature of the area and the main challenges faced by the participants about the didactic transposition of HPS for the educational context they were noted during the workshop. The relevance of this second front, in particular, is justified by the existence of gaps with regard to the inclusion of the theme of NOS and the HPS teacher training

Fontes primárias da história do vácuo e da pressão atmosférica na sala de aula: cartas e jornais históricos em articulação com o livro-texto do ensino médio

The use of the History and the Philosophy of Science (HPS) for the teaching of science and scientific subjects has been advocated in recent decades. It has been pointed out that the History of Science could make for a deeper learning of scientific concepts, since it would promote a contact with the problems which that knowledge has set out to solve. Furthermore, historical episodes would serve to put the discussions about the nature of scientific knowledge into context. With a view to explore those potentialities, the literature in the field has sought to identify the challenges and obstacles for the didactic transposition of subjects from the History of Science. Amongst many aspects, the deficiencies in the training of teachers, so that they can work with the insertion of HPS in the classroom have been highlighted. Another aspect that has been mentioned to be a challenge has to do with the didactic transposition of the Primary Sources, that is, of the original texts on the History of Science. The Primary Sources have significant potentialities: making a connection possible between scientists and concepts, showing the difficulties faced during scientific endeavors, perceiving the role of mistakes as obstacles to be surpassed, not as defeat, etc. On the other hand, there has been little exploration of these concepts in an educational context, due to their own peculiarities. The original texts are often hard to understand and their interpretation demands knowledge of the historical and scientific context in which they were written, as well as skills pertaining to the conduction of research in the field of the History of Science. With this scenario in mind, the research towards this Professional MSc degree starts from the challenge of elaborating and discussing proposals which could enable the didactical transposition of the Primary Sources. We have worked specifically with Primary Sources on the History of the Vacuum and of the Atmospheric Pressure, because of the insertion of these subjects in the Brazilian High School curriculum, in connection with the didactical textbooks. "Historic Journals" were made up from clippings of the original historical texts, as was a Didactical Unit, which takes the usual textbooks as a basis and contemplates using the Journals and the entire Primary Sources in High School. At last, we have elaborated and implemented a course designed for the preparation of teachers and for being an opportunity for the discussion of the feasibility of putting these kinds of proposal into practice

Testes cinemáticos em cosmologia com decaimento do vácuo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Anisotropias da radiação cósmica de fundo e vínculos em modelos com decaimento do vácuo

Many astronomical observations in the last few years are strongly suggesting that the current Universe is spatially flat and dominated by an exotic form of energy. This unknown energy density accelerates the universe expansion and corresponds to around 70% of its total density being usually called Dark Energy or Quintessence. One of the candidates to dark energy is the so-called cosmological constant (Λ) which is usually interpreted as the vacuum energy density. However, in order to remove the discrepancy between the expected and observed values for the vacuum energy density some current models assume that the vacuum energy is continuously decaying due to its possible coupling with the others matter fields existing in the Cosmos. In this dissertation, starting from concepts and basis of General Relativity Theory, we study the Cosmic Microwave Background Radiation with emphasis on the anisotropies or temperature fluctuations which are one of the oldest relic of the observed Universe. The anisotropies are deduced by integrating the Boltzmann equation in order to explain qualitatively the generation and c1assification of the fluctuations. In the following we construct explicitly the angular power spectrum of anisotropies for cosmologies with cosmological constant (ΛCDM) and a decaying vacuum energy density (Λ(t)CDM). Finally, with basis on the quadrupole moment measured by the WMAP experiment, we estimate the decaying rates of the vacuum energy density in matter and in radiation for a smoothly and non-smoothly decaying vacuum

Avaliação de meios filtrantes primários em filtro contínuo de tambor rotativo a vácuo para lodo de caldo de cana

Este estudo teve o objetivo de avaliar o comportamento de treze tipos de meios filtrantes primários desenvolvidos para uso na filtração a vácuo de lodo de caldo de cana, simulando as operações de formação e desidratação da torta em filtros contínuos de tambor rotativo a vácuo, empregados nas indústrias de açúcar e álcool do Brasil. Para tanto, foi desenvolvida uma planta-piloto anexa ao filtro de tambor rotativo a vácuo, na qual foram realizados todos os ensaios, com o objetivo de refletir a realidade das variáveis operacionais durante uma safra sucroalcooleira. Os resultados são apresentados, comparando-se as taxas de filtração, variando a pressão de formação da torta, temperatura e concentração de auxiliar filtrante, mostrando ao usuário um novo caminho para o melhoramento quantitativo e qualitativo, sem aumentar a área nominal da unidade de filtração.

Análise da variabilidade do processo de filtração em filtros de tambor rotativo contínuo a vácuo para lodo de caldo de cana de açúcar

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Determinação do tempo de vácuo, momento de coleta e posicionamento de extratores de cápsulas porosas em solo arenoso

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Associação de bactérias da família Enterobacteriaceae e Clostridium estertheticum com a deterioração blown pack em cortes cárneos embalados a vácuo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Analise de viabilidade técnica-econômica na substituição de um sistema combinado de geração de vapor-vácuo por bombas secas

Pós-graduação em Engenharia Mecânica - FEG

Estudo analítico de alguns aspectos da dinâmica na frente de luz: transformações de Lorentz, sistemas de dois corpos em interação, polarização do vácuo e integrais de Feynman

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Irradiação e qualidade da carne de frango congelada e embalada à vácuo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)