1000 resultados para Engenharia eletrónica


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Currently, in Brazil, the quantity and quality of new types of wastes, discarded without criteria in urban areas, has been responsible for considerable impacts on public health and the environment. According to a report prepared by the Institute of Applied Economic Research (IPEA), the country loses about U.S. $ 8 billion annually, due lack of waste recycling, which go directly into landfills or dumps. Among these solid wastes are waste electrical and electronic equipment (WEEE), whose characteristics are complex, by having in its composition substances of high value-added and other health hazards which require different treatment of household waste. Aiming to fill the gap in Brazilian environmental legislation, on 02/08/2010, was sanctioned the National Policy Solid Waste (Law No. 12,305), already regulated on 23/12/2010 (Decree No 7404), whose based on the following principles:reduction of waste generation and toxicity of shared responsibility, proper planning management, social inclusion of waste pickers and sustainable production and consumption. Given the above, this work presented here, aims generally present a diagnosis of the current situation of electronic waste generated in the Faculty of Engineering, Campus Guaratinguetá, FEG / UNESP, to provide data for management and management of these waste, based on sustainability, the economic losses and minimizing environmental impacts and public health related to the flow and the improper disposal of these wastes

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To know the profile of research of each Department of Education is of utmost importance for future actions of improvements. This type of study must be made continuously of form to evaluate Departments´ trends as well as the College´s as a whole, besides stimulating the activities of research and formation of human resources of the Departments. In this work is quantified activity of orientation and research of the Departments of the College of Engineering of Guaratinguetá - UNESP, through national and international publications in periodic, congresses and supervisions of graduation works, masters, doctoral, post doctoral, and scientific initiation, in a period five years (2007 through 2012). For balance of points to the considered issues, a criterion based on the CAPES qualification of periodic has been assumed. On the basis of the results of this work, has been observed enormous differences and particularities between the seven analyzed Departments of Education. In a general way, some Departments presented good performance in the three criteria, whereas others obtained a good performance in only one of them. The Department of Materials and Technology was the only one in which 25% of the professors obtained maximum note for the publication in periodic, while in the Departments of Civil, Electric Engineering and Mechanics 75% of the professors did not reach sufficient punctuation in order to equal a publication in periodic with B2 extract

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Diuron (3-(3,4-Dichlorophenyl)-1,1-dimethylurea) is a substituted urea herbicide widely used on agricultural crops such as soy, cotton and sugar cane. In a previous long-term study this herbicide exerted carcinogenic activity on the urinary bladder and renal pelvis mucosa of Wistar rats and breast of mice. Also, it was shown to be carcinogenic to the mice skin in a initiation-promotion assay. In 1997, the northamerican EPA evaluated Diuron as a “known/likely” carcinogen for humans (USEPA, 2004). In a previous study developed at this laboratory, male Wistar rats treated with Diuron 2500 ppm during 20 weeks presented increased indices of cell proliferation and incidences of simple urothelial hyperplasia (HS) in the urinary bladder. Under scanning electron microscopy (SEM) severe urothelial necrosis and hyperplasia were observed. However, in that study the urinary bladders of animals exposed to lower doses of Diuron were not examined under SEM. Therefore, the possible dose-response influence of Diuron on the urothelium under SEM is not known. The present study aimed to analyze under SEM the urinary bladder of male Wistar rats exposed to 125 ppm, 500 ppm and 2500 ppm doses of Diuron through diet during 20 weeks and to compare to the previous histological findings in the same material. Under SEM, 125 ppm and 2500 ppm groups presented significantly (p<0,05) increased incidences of simple hyperplasia, i.e., 7/10 and 8/10 respectively, compared to control group and the 500 ppm group The sensitivity of SEM was higher since it detected a 45% incidence of hyperplasiaswhile the histological analysis found only 27%. Considering SEM as the gold-standard, histology showed a 44% sensitivity, 86.4% specificity, a positive predictive value of 72,7% and negative predictive value of 65,5% and accuracy of 67,5%. Scanning Electron Microscopy...(Complete abstract click electronic access below)

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Brazil is nowadays the greatest bet of investors for the future due to its stable economy growth. The country has grown side by side with the greatest demand for electrical energy. The international appeal for renewable sources is causing a change in the Brazilian energetic matrix, raising the amount of energy generated by thermoelectric power plants. The construction of new power plants, running on biomass, requires a crescent number of capacitated personnel to run them. The Faculdade de Engenharia de Guaratinguetá – UNESP – has a steam laboratory; witch is deactivated, which has a thermoelectric plant of small capacity. The laboratory reactivation and the return of its activities can be an important tool in order to graduate engineer able to operate on such units. This paper proposes four new experiments to be simulated on the Collage’s Energy Dep. Steam Lab when it gets back to its educational activities

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The glassy carbon is a material with a huge technological evolution. Due to its lightness, biocompatibility and their thermal and electrical properties this material finds applications in several industrial fields such as electronics, medical, aerospace and chemical. In order to explore the conductive properties of glassy carbon for use as modified electrodes, the present work aims the processing of monolithic and reticulated glassy carbon with colloidal copper for use in electrochemical applications. First, the best parameters for the cure of furfuryl alcohol resin doped were established through viscosimetry measurements and pressurized differential scanning calorimetry. The analysis of the micrographs of the cured resins show that copper concentrations above 3% weight, generate higher porosity in the material. The characterizations of the monolithic and reticulated glassy carbon resulting from carbonization were performed by scanning electron microscopy (SEM), Raman and Electrochemical impedance spectroscopy, and although it was not possible to detect the presence of copper by SEM, the influence of these particles have been observed by Raman and FT-IR spectra and electrochemical behavior of the material. The decrease in conductivity of monolithic and reticulated glassy carbon in the presence of copper may be related to the defects caused by the presence of copper in the structure of the material.

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This conclusion thesis has the objective of produce substrates of Silicon Carbide from the powder of SiC for aerospace use. The powder of SiC was pressed in cylindrical form by the process called “wet way”. For the inicial pressing process was used a uniaxial squeezer and after that was used a isostatic squeezer, after that the samples were synthesized. The next step was the machining and polishing to improve the features of the surface of the sample. Then the roughness was measured, as also the Arquimedes method and optical microscopy and scanning eletron microscopy. Some innovations were done, in one of the lots little vacancys were done with organic material or silicon to reduce the weight of the sample; and the other innovation were the use of a slip film of SiC on the surface of the sample, that were after synthesized with LASER to reduce the roughness, in this samples the roughness were reduce in 50 % if compared with the other samples

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In our experiments, we studied the classical dynamic of a particle in vertical motion subject to a constant gravitational field and the partial shock with an elastic wall with oscillatory motion located below the particle. The motion of the particle was confined to the vertical direction by a glass guide tube, which was initially evacuated, allowing viscous drag forces to be disregarded. The time between impacts, as well as the time between the reference phase of the movement of the base and the moment of impact and the period of oscillation of the base will be acquired by a hardware and software to obtain the phases space to be compared later with the description of the system through mapping discrete variables via the 'particle velocity immediately after shock 'and' phase of the movement of the base at the instant of shock 'obtained by computer simulation. This requires developing an electronic analog system followed by Digital implemented in reconfigurable logic, more specifically a sequential machine able to discriminate the impact with the metal base from the impacts of the glass guide tube, based on the frequency spectrum of the response of the microphone to these different impacts

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This work aims to show the importance of Baja SAE Project in engineering education, as well as the development of the student, being an outstanding tool for the engineering student has an education that meets the objectives of the pedagogical university and also the guidelines Ministry of Education curriculum for engineering courses. The Baja SAE Project provides the engineering students the chance to apply in practice the knowledge acquired in the classroom, to enhance their preparation for the labor market. The student becomes involved with a real case of project development, from concept design, detailed design and construction. The Baja SAE Project redefines the position of the student as an active element in the learning process engineering, leaving behind the simple condition of receiving information. Values procedures that provide students the opportunity to learn in contexts of professional practice, while offering the opportunity to contextualize the execution of a project. From an analysis to develop personal skills, Baja SAE Project has its own characteristics and essential for professional practice, however, not specific to the engineering course. For example, capacity for teamwork, communication skills written and oral, ethical behavior, critical, overview, entrepreneurial spirit, leadership, etc

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This work aims to verify and compare the efficiency of heat exchangers used in the thermal systems laboratory at Faculdade de Engenharia do Campus de Guaratinguetá - UNESP. Basically, it has been studied two types of heat exchangers: plate type, operating in parallel flow and counter-flow, shell and tube type and also operating in parallel flow and counter flow. Initially it has been presented the didactic equipment and procedures for use of these heat exchangers in the proposed experiments. With the results obtained from the experiments, comparisons were made in order to define the behavior of the heat exchangers regarding some variables. In the study, one comes to the conclusion that the results from shell and tube type of heat exchanger, used in the thermal systems lab, are superior in all conditions analyzed

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The protection and distribution systems for the electrics equipments are really important for the safety of products, process and final users, for an enterprise or even for a residence. For that, it’s necessary the utilization of low voltage switchboards for controlling the feeding of a charge, avoiding any kind of abnormality that can eventually occur. It’s necessary to pay attention in the cubicles conditions, and always verify if they are in accordance to the norms of the product, verifying also any kind of physical damage for the operator and/or users. In this line, the present graduation work analyses the low voltage switchboards in the college, checking if they are attending the actual standards, suggesting some improvements and later making a simulation of the creation of a new panel that reach all the needing in substitution of this actual, through the software Simaris. Using the research and lecture of norms and regulations for verifying the problems, this way we could register the greatest acting failures. These actions are made for becoming aware to the university about the danger in using electrics equipments without a minimum degree of protection, allowed by the law, and attempting to the urgency in changing this fails

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Thin polymeric films deposited by plasma are very atractive for many industrial and scientific applications, in areas such as electronics, mechanics, coatings, biomaterials, among others, due to its favorable properties such as good adhesion to the substrate, high crosslinking, nanomectric thickness, homogeneity, etc. In this work, thin films were deposited by plasma immersion ion implantation and deposition technique from a hexamethyldisilazane/argon mixture at different proportions. These films were subjected to several characterizations, such as, contact angle, which presented values near to 100 degrees, surface energy, with values near to 31 mJ/m2, hardness with values between 0.7 and 2.6 GPa, thickness from 100 to 200 nm, refractive index from 1.56 to 1.64, molecular structure presenting the following functional groups in the infrared spectra region: CHx from 2960 to 2900 cm-1; Si-H around 2130 cm-1; CH3 in Si-(CH3)x around 1410 cm-1; CH3 in Si-(CH3)x in 1260 cm-1; N-H around 1180 cm-1; CH2 in Si-CH2-Si bonds around 1025 cm-1; Si-O in Si-O-Si from 1020 to 1100 cm-1; Si-N in Si-H-Si bonds around 940 cm-1; CH3 in Si-(CH3)3 in 850 cm-1; Si-C bonds in Si-(CH3)2 around 800 cm-1; and Si-H in 680 cm-1 . From these characterizations, it was possible to conclude that the concentration of argon or hexamethyldisilazane in the mixture changed the resulting polymer

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There is a need for ongoing evaluation of the researchers not only engineering and production in all areas of knowledge engineering. To check the quality and veracity of scientific production, the CNPq is a brazillian government agency designed to evaluate researchers, classify them and give the encouragement and incentive for their research. This study quantifies the CNPq researchers in the field of Production Engineering according to the time of operation in research, number of guidelines for masters and doctoral, number of articles in national and international journals or magazines and congresses. The classification of these researchers, according to the proposed quantification, is confronted with the level of research they have in CNPq. The researcher starts his career at level 2, after it spending levels for 1D, 1C, 1B reaches to the highest level 1A. The main conclusion to be drawn from this study is that excellent researchers with a significant number of guidelines, bitter years in the early levels because of the rules of the CNPq which only allows a researcher to achieve the highest levels after many years of research

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The monolithic glassy carbon is a carbonaceous material, isotropic, non graphitizable obtained by means of carbonization of resins up to 1000 °C. The good physicochemical properties make this material applied in several areas such as aerospace, medicine, electronics, chemistry, among others. It has generally been processed from the use of phenolic and furfuryl alcohol resins. These resins have high crosslink density and high fixed carbon content and are therefore widely applied in aerospace. The combination phenol / furfuryl alcohol resins search for obtaining the most suitable process for the glass-like carbon processing with phenolic resins currently available and of lower cost and easier to synthesize than the furfuryl alcohol resin. The main objective of this work is to obtain a phenol-furfuryl resin with high fixed carbon content combined with low porosity of the material. Different synthesis routes have been adopted along with thermal analysis techniques, FTIR and image analysis. The resin obtained through partial synthesis process presented the characteristics sought in this work

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The current work aims to analyze the contributions of PIBID for initial graduation of the teachers, in view of the undergraduates of Physics Course at UNESP Guaratinguetá . A brief literature survey about the national situation of teacher education was performed, at which the main difficulties and challenges, as well as the solutions stated in place by the government to solve them, have been highlighted. A description of the historical of PIBID at UNESP, from the institutional project to reach the subproject developed by Physics Course of Guaratinguetá, was presented. To characterize the development of the subproject, it was performed a survey on the activities performed by the PIBID’s scholars, since its implementation on campus in 2010 until the end of the year 2013, in order to map the experiences lived by program participants. These data were obtained from the analysis of reports by scholars themselves, video analyzes and record of the weekly meetings held by the group, reading electronic messages exchanged on a specific group of e-mails and written evaluations by members of the program. Completing data collection, eleven scholars undergraduates of the program were interviewed, and the results were classified by topics, defined from recurrence in the interviewees speech. The global analysis of the data was based on theoretical references commonly used in research on graduation of teachers, as Nóvoa (1992), Mizukami (2005, 2006) and Gatti (2008). The results indicate that the licensed ones see in PIBID a differentiated opportunity for initial teaching graduation, for adding practical learning experiences for students of EB within the school context, and especially for creating space for reflection on their experiences with the support of more experienced teachers, committed to the training of all involved ones

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Nowadays technological trend is based on finding materials that could support low weight with satisfactory mechanical properties and for this reason composite material became a very attractive topic in research projects all over the world. Due to its heterogenic properties, this type of material shows scatter in mechanical test results, especially in cyclic loading. Therefore it is important to predict its fatigue strength behaviour by statistic analysis, once fatigue causes approximately 90% of the failure in structural components. The present work aimed to investigate the fatigue behaviour of the Twill/Cycom 890 composite, which is carbon fiber reinforced with polymeric resin as matrix and manufactured via RTM process (Resin Transfer Molding). All samples were tested in different tensile level in triplicate in order to associate these values. The statistical analysis was conducted with Two-Parameter Weibull Distribution and then evaluated the fatigue life results for the composite. Weibull graphics were used to determine the scale and shape parameters. The S-N curve for the Twill/Cycom composite was drawn and indicated the number of cycles to occur the first damages in this material. The probability of failure was associated with material reliability, as shown in graphics for the different tensile levels and fatigue life. In addition, the laminate was evaluated by ultrasonic inspection showing a regular impregnation. The fractographic analysis conducted by SEM showed failure mechanisms for polymeric composites associated to cyclic loadings ... (Complete abstract click electronic access below)