Estudo teórico da contribuição do espalhamento nuclear não elástico na trajetória de prótons de energias entre 50 e 250 MeV em materiais de interesse em radiologia: aplicação em tomografia com prótons

The goal of this work is to study the process of interaction of protons with matter through Monte Carlo simulation. For this purpose, it was employed the SRIM program (Stopping and Range of Ions in Matter ) and MCNPX (Monte Carlo N-Particle eXtended) v2.50. This work is going to support the development of a tomography system with protons. It was studied the interaction of proton with the follow materials: Polimethyl Mehacralate (PMMA), MS20 Tissue Substitute and water. This work employed energies in range of 50 MeV and 250 MeV, that is the range of clinical interest. The energy loss of proton after cross a material layer, the decreasing of its intensity, the angular and lateral de ection of incident beam, including and excluding nuclear interactions. This work is related with Medical Physics and Material Physics, like interaction of radiation with matter, particle transport phenomena, and the experimental methods in Nuclear Physics like simulation and computational by Monte Carlo method

Melhoria da qualidade de um processo de usinagem utilizando as técnicas de avaliação de Taguchi

Delivering to the customers a product or service with the expected quality associated to the huge competitiveness that exists in the market nowadays, has been making organizations increasingly focus on quality planning using techniques which are directed towards the continuous improvement process and production optimization. Thus, this paper aims to improve a machining process using the techniques of experimental design to the optimization and this also includes the analysis of the measurement system. For this purpose, the alloy Nimonic 80A, a nickel base superalloy, was used in the process due to its widespread use for high temperatures, applying this study the robust method proposed by Genichi Taguchi, determining the influence of the factors considered input variables, cutting speed, feed rate, depth of cut, type of tool, lubrication, and material hardness, in the output or response variable, surface roughness, concluding with the use of Taguchi orthogonal array L16 and by analysis of ANOVA that the factor feed rate is significant and offers greater effect on the response variable studied, should be set to 0,12mm/rev. Moreover, the factor type of tool has more influence on the process when compared to other factors, being CP250 the one more suitable to the process. Lastly, the interaction feed rate x cutting speed provides greater significance in the process regarding to surface roughness variable, being the best match between them 0,12mm/rev to the feed rate and 90m/min to the cutting speed. In order to evaluate the measurement system, it was applied the repeatability and reproducibility method (R&R), through which we saw that the system needs improvement (R & R = 88.04% >>> 30%) as the value found in the study was well above compared to the one that classifies the system as inappropriate

Produção de partículas secundárias em reações de “spallation” induzidas por prótons

Cosmic radiation has been identi ed as one of the main hazard to crew, aircraft and sensitive equipments involved in long-term missions and even high-altitude commercial ights. Generally, shields are used in spatial units to avoid excessive exposure, by holding the incident radiation. Unfortunatelly, shielding in space is problematic, especially when high-energy cosmic particles are considered, due to the production of large number of secondary particles, mainly neutrons, protons and alpha particles, caused by spallation reactions and quasi-elastic processes of the corpuscular radiation with the shield. Good parameters for checking the secondary particle production at target material are diferential cross section and energy deposited in the shield. Addition experiments, some computer codes based on Monte Carlo method show themselves a suitable tool to calculate shield parameters, due to have evaluated nuclear data libraries implemented on the algorithm. In view of this, the aim of this work is determining the parameters evaluated in shielding materials, by using MCNPX code, who shows good agreement with experimental data from literature. Among the materials, Aluminium had lower emission and production of secondary particles

Otimização do processo de usinagem da superliga nimonic 80A utilizando o Método de Taguchi

Atualmente, atender as necessidades dos consumidores é uma das metas mais importantes, os consumidores estão em busca de produtos com qualidade e preços mais acessíveis, para isso, é indispensável que as empresas se atualizem para melhorar seus produtos e serviços. Com este cenário, as superligas estão cada vez mais ganhando mercado, pois possuem ótimas propriedades, principalmente em relação a operar em temperaturas elevadas, podendo proporcionar maior eficiência para motores que necessitam trabalhar em altas temperaturas. Em contra partida a essa vantagem, as superligas possuem uma baixa usinabilidade, sendo importante a análise do processo de usinagem para se tornarem mais aplicáveis. Este trabalho visa à otimização do processo de torneamento cilíndrico da superliga Nimonic 80A, com o intuito de melhorar a qualidade do produto, utilizando o Método de Taguchi, com o arranjo ortogonal L16, sendo o comprimento de corte definido como variável resposta e analisados seis fatores que poderiam influenciar na sua variação, tais fatores são: velocidade de corte, avanço, profundidade de corte, tipo de pastilha, lubrificação e dureza do material. Os resultados obtidos demonstraram que os fatores avanço, tipo de pastilha e lubrificação são significativos e exercem influencia no processo, sendo que o avanço deve ser ajustado no nível de 0,12 mm/rev, a pastilha a ser utilizada deve ser CP250 e a lubrificação deve ser feita de maneira abundante, para a otimização do processo. Com a análise dos resultados, também podemos observar a eficiência e confiabilidade do método utilizado, mostrando resultados coerentes

Estudo sobre qualidade de voo no modo longitudinal da aeronave e análise do critério de largura de banda

The flight quality describes the skills of the pilot realize a given task and its difficulty to perform it. Flight quality criteria provide a valuable reference for the designers during the requirements definitions phase and to develop them during the phase of flight testing. These criteria were taken important for the development of a fly-by-wire system. There are several flight quality criteria and this work analyzes the bandwidth criteria, this is evaluated according to a model an aircraft using the SIMULINK/MATLAB. In addition, the paper also describes in detail what is a flight quality criteria and shows an overview of the bandwidth criteria

Desenvolvimento de recobrimento submicrométrico de óxido de nióbio para aplicação em tubulações de prospecção de petróleo

Pós-graduação em Engenharia Mecânica - FEG

A ideologia dos meios de comunicação social na formação da consciência familiar

Pós-graduação em Serviço Social - FCHS

Métodos numéricos para encontrar zeros de funções: aplicações para o Ensino Médio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A dimensão dialógica e a prática educativa: reflexões a partir de Paulo Freire e Humberto Maturana

Ao observarmos o cotidiano nas escolas é possível constatar que nem sempre se reconhece e se valoriza a diferença e a singularidade que caracteriza cada sujeito envolvido, pois ocorrem situações de negação mútua entre alunos, entre alunos e professores e entre outras relações do espaço escolar que ferem a dignidade humana. Uma alternativa a essa realidade é a promoção de vivências dialógicas. Nesse sentido, objetivamos com este trabalho: Refletir sobre as contribuições teórico-conceituais desenvolvidas por Paulo Freire e por Humberto Maturana acerca da vivência do diálogo, suas possibilidades e impasses nas relações sociais e na relação educativa; e identificar, a partir de um estudo de caso realizado em uma escola da Rede Pública Estadual, as concepções dos educadores sobre a prática dialógica no cotidiano escolar. Para Freire, o diálogo é o encontro e a partilha de concepções de A com B e não de A sobre B ou vice versa, sendo que nesta relação é importante que ambos se disponham à escuta mútua reconhecendo a diversidade de concepções que estimula a curiosidade epistemológica. Para Maturana, a partir da Biologia, cada ser vivo se constitui como uma organização autopoiética, ou seja, tem a tarefa de produzir-se a si próprio, estabelecendo relações com o meio. Na existência humana, essas interações com o meio e entre os humanos se estabelecem num entrelaçamento de emoções e ações, que ele nomeia de conversação. A partir das reflexões pelos autores e o diálogo estabelecido com sujeitos da pesquisa destacamos: 1) As relações sociais se mantêm quando há aceitação do outro como legítimo outro na convivência, o que implica a aceitação de si próprio; 2) O diálogo cria um clima de aceitação para com a história e a diferença do outro, o que favorece relações de partilha de ideias e de releitura coletiva do mundo. Tanto Maturana e Freire, quanto os entrevistados valorizam o ...

Viabilidade do Código MCNPX para o Estudo da Técnica de Fluorescência de Raios-X por Reflexão Total

The X-ray fluorescence analysis (XRF) is an important technique for the qualitative and quantitative determination of chemical components in a sample. It is based on measurement of the intensity of the emitted characteristic radiation by the elements of the sample, after being properly excited. One of the modalities of this technique is the total reflection x-ray fluorescence (TXRF). In TXRF, the angle of refraction of the incident beam tends to zero and the refracted beam is tangent to the sample-support interface. Thus, there is a minimum angle of incidence that there is no refracted beam and all the incident radiation undergoes total reflection. As it is implemented in very small samples, in a film format, self-absorption effects should not very relevant. In this study, we evaluated the feasibility of using code MCNPX (Monte Carlo N - Particle eXtended), to simulate a measure implemented by the TXRF technique. In this way, it was verified the quality of response of a system by TXRF spectroscopy using synchrotron radiation as excitation beam for a simple setup, by retrieving the characteristic energies and the concentrations of the elements in the sample. The steps of data processing, after obtaining the excitation spectra, were the same as in a real experiment and included the obtaining of the sensitivity curve for the simulated system. The agreement between the theoretical and simulated values of Ka characteristic energies for different elements was lower than 1 % .The obtained concentration of the elements of the sample had high relatively errors ( between 6 and 60 % ) due mainly to lack of knowing about some realistic physical parameters of the sample , such as density . In this way, this result does not preclude the use of MCNPX code for this type of application

Narrativa e encenação: um estudo sobre diálogos e monólogos em contos de Marcelino Freire

Pós-graduação em Letras - FCLAS

Melhora da aptidão neuromuscular em indivíduos não treinados em força realizando método das séries simples e múltiplas

The purpose of this study was to evaluate the performance of individuals not trained in methods under performing resistance exercise in the method of multiple series and the following exercises: Leg press (LP) 45, leg extension (CE), leg curl (CF), front handle (PF), rowing neutral (RN), bench press (SR) and Peck deck (PD) in 9 weeks with three training sessions / week. The study was with of 6 individuals aged 40 to 55 years were divided into two groups all were tested using the 1 RM for securing cargo to the drills being performed each test 48 h. Results: According to what was observed using this training protocol with different volume in each group for 9 weeks of training in these subjects did not differ in both groups but showed increases above two devices with other evaluated Peck deck and this is due Leg Press major muscle group.

Os limites e as possibilidades de uma sequência didática: o conceito de proporcionalidade e a aprendizagem de alunos do 5º ano do Ensino Fundamental

This study aimed to analyze the limits and possibilities of a didactic sequence, addressing the concept of proportionality in the learning of students in 5th year of elementary school. From the results of the Diagnostic Assessment Initial applied to students in a class of 5th grade of elementary school, we selected eight (8) students who participated in the constituent activities of that instructional sequence. For the development of this sequence were used theoretical elements of Genetic Epistemology (Piaget, 1990), the theory of fields of Conceptual Vergnaud (1996) and the definition of instructional sequence proposed by Zabala (1998). Finally, after 20 days of application of these activities, we applied the Diagnostic Assessment Final aimed at investigating which concepts related to proportionality were built by the participating students. By analyzing the collected data, it can be concluded the following about the possibilities of teaching sequence: 1) students who, in Diagnostica Home Assessment used the multiplication algorithm, but also did not indicate the comparison between quantities are now performing; 2) students who, in the Diagnostic Assessment Initial, used the addition algorithm, now gradually are using the multiplication algorithm; 3)students who, in the Diagnostic Assessment Initial, could not solve problems involving the idea of proportionality, are now resolving, however, still use, in large part, the addition operation as a strategy for this proportional thinking. Now, in relation to the limits of the sequence noted: 1)time sufficient to propose a higher number of problem conditions to be carried by students who may have been a trigger of construction have not through the proportional multiplication;2)the distant proposition situations of assimilation schemes (interpretation) of the students, which may have caused certain imbalance in them, preventing them from thinking about the problem situation;3)the rapid passage of...

Alfabetização de jovens no 6º ao 9º ano na perspectiva freireana: uma intervenção educativa para a vida na escola e no mundo

By showing how the problem of illiteracy is present among adolescents 11-14 years of age, attending school regularly, and realize how much this problem affect your life not only in school but also in their participation in society, it has set the aim of this research to alphabetize and write the lyrics registered adolescents of elementary school (6th to 9th grade) in a public school, by the Paulo Freire alphabetization method. The type of research that best responds to the proposed objective was action research with a qualitative approach. The data obtained from this research were analyzed in three topics: the search and selection of generating words, technical literacy and consciousness of each generating words (encoding and decoding of the situation experienced this situation with critical weight, pragmatic), and in the end, the analysis of the production of genre personal letter. The survey results indicate that, indeed, it is possible to write the lyrics and literate adolescents with Freirean literacy method. Also indicate the need to continue this work with the subjects of this research to develop linguistic and discursive skills to dominate the genre studied, both in the phenomenon of literacy, as in the write the lyrics. The results also point to another need, which is the extension of this research work in the community and other schools of the city, who have this problem of having teenagers in Elementary Education II, without being literate, as an alternative to overcome this major problem of illiteracy

As avaliações externas e suas implicações para a organização do trabalho numa escola da rede estadual paulista: um estudo de caso

This research analyses the positives and/or negatives of external reviews to work's organization developed at the/and by the school. It should be noted that it's a qualitative case of empirical research, and it takes the pattern of case's study, because we held the investigation just in one school, which in turn, belongs to the education's public network by the state, and is located at the São Paulo northwest. The tools employed at this research for the data's collect were the observation, restricted to times of Pedagogical Work Activities Collective from the school, and the semi structured interviews with educational coordinators and the teachers too. We choose educational coordinators and teachers because they are closer with the education and learning methods, as well as their activities have more responsibility in relation to the main function developed by school, that is to teach, in other words, educational processes. This research also concerns an investigation about the educational coordinators and teachers conceptions, in relation to system's implantation external reviews at the schools. The results indicate to incidence of significant interference of the external reviews to/in the organization school's work, as, a teaching practice reorientation from results arising these reviews, or, modifications in the internal rating, since they have followed a tendency towards becoming more similar with their own external reviews. In what concerns the subjects investigated, we can emphasize that mostly submitted alienation with respect to negative effects of the external reviews for school. They showed that are conformed with the reality that they are inserted and in your mostly they proved perceive the positive effects by the implantation of external reviews. We can also add that the data obtained in the research allow us declare that the work of the educational coordinators of this school in presence of external reviews don't...