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Santos P.A.,Servico Nacional de Aprendizagem Industrial SENAI | Altuna J.A.T.,Federal University of ABC | Casella I.R.S.,Federal University of ABC | Sguarezi Filho A.J.,Federal University of ABC | Capovilla C.E.,Federal University of ABC
IEEE Latin America Transactions | Year: 2015

The employment of PWM drives in induction motors control has been widely used in industry. However, in some applications in hazardous areas, such as drilling, the PWM drive cannot be physically close to the motor, being necessary the use of long cable drives. This fact leads to the generation of overvoltage peaks on the induction motor terminals, which can cause interference in the speed control, reduction of equipment lifetime, or even, permanent damages. In this context, this work presents alternatives to minimize the overvoltage effect based on the use of transformers and analyzes the performance of the speed control of each proposed technique. © 2003-2012 IEEE. Source

Mendes Vasco A.,University of Northern Parana | Abrahao Amaral M.,Federal Technological University of Parana | Sardinha Martins N.,Servico Nacional de Aprendizagem Industrial SENAI | De Fatima Bartholo V.,University of Northern Parana
IEEE Latin America Transactions | Year: 2011

The use of technology is bringing about changes in education. Teaching through the computer gives a position to acquire concepts about any field of knowledge. In this context, learning objects are presented as a possibility to enhance the procedure for implementing the curriculum because they are considered portions of content that can be reapplied to different audiences in different situations. This paper describes the principles that underlie the creation of a Learning Object Science and its application in order to contribute to the concepts of Soils of elementary education. © 2011 IEEE. Source

Braga M.S.,University of Sao Paulo | Matos K.R.M.,Servico Nacional de Aprendizagem Industrial SENAI | Borges V.F.,University of Sao Paulo | Gomes O.F.,University of Sao Paulo | Salcedo W.J.,University of Sao Paulo
Chip in Curitiba 2013 - SBMicro 2013: 28th Symposium on Microelectronics Technology and Devices | Year: 2013

Photoluminescence quenching-based sensors for oxygen detection are generally made with organic dyes molecules that act as active molecules. These molecules are normally immobilized into polymeric host substrate that doesn't have any compatibility with silicon technology. In this work we report a photoluminescence (PL) quenching based oxygen sensor using oxidized porous silicon layer as a host matrix for platinum-octaethylporphyrin (PtOEP) dye molecules. The device in this substrate is high sensitivity because its high surface area and it may have high compatibility with silicon technology since porous silicon is obtained on silicon substrate. The sensitivity to O 2 detection of this sensor was 13 times higher than to conventional devices based on polystyrene layer and its response time was 3 times slower than polymeric based devices. In the present work, the detection mechanism and the response time of these sensors are discussed. © 2013 IEEE. Source

Mozetic H.,Centro Universitario Ritter dos Reis | Boff U.,Centro Universitario Ritter dos Reis | Luna W.H.D.,Servico Nacional de Aprendizagem Industrial SENAI | Pfingstag M.E.,URI Integrated Regional University Brazil | And 3 more authors.
Journal of Electrical Systems | Year: 2016

The purposes of this paper were to study the thermal treatment of Fe-Si sheet, as well as the sheet cutting concerning the topology of a mini stepper motor and mini motor simulation using finite element software. The research consisted of the execution of an "Inductive Reheating" thermal treatment of Iron Silicon sheets, NM71-2000/35F 420M with GNO (Grain Non Oriented), and 0.35mm width. The new technique has the benefit of minimizing magnetic losses produced by the cut on the edge of electric sheets. To carry out the process, the system includes a furnace, an induction coil, and a power supply that, when activated in a controlled way, causes relevant changes to the crystalline structure of the material. Related to the cut of the sheets, the topology of a three phase mini stepper motor was considered. The sheets were initially cut using the geometry of the rotor and stator cores. Firstly, a die cutting process was used and later a wire electroerosion cutting process was employed, which provided parts with excellent finishing. Finally, the mini motor was simulated using the finite element software FEMM 4.2 in order to analyze the airgap flow and torque development of the axis end, in comparison to a solid block of the same material (Fe-Si). Copyright. © JES 2016. Source

Costa F.D.,Servico Nacional de Aprendizagem Industrial SENAI | Teo C.R.P.A.,Chapeco Region Community University | de Almeida J.S.,Chapeco Region Community University
Scientia Medica | Year: 2015

Aims: To analyze stress vulnerability in the work context and its effects on feeding. Methods: Cross-sectional study of industrial workers from Santa Catarina state, southern Brazil. The occupational stress vulnerability scale (OSVS) and a structured questionnaire were used as instruments. Six sociodemographic and occupational variables (age, sex, schooling, work shift, work sector/unit, duration of employment), level of stress vulnerability (according to the OSVS), in addition to five nutritional variables which took into account self-reported stress rather than the vulnerability evaluated by the OSVS were assessed. Student's t test, Pearson's chi-square test, and linear trend were used for data analysis, and statistical significance was set at 5% (p ≤ 0.05). Results: A total of 309 industrial workers were assessed. The mean age was 30.9±10.1 years; 60.2% were women; 44.7% had attended high school; and 25.5% had finished elementary school. The median duration of employment was about 23 months (interquartile range of 7-57); 81.6% worked during the day, and 18.4% at night. The mean score of stress vulnerability was 22±11.6 points; 249 (80.6%) workers were classified at the lower levels of stress vulnerability and 60 (19.4%) at the upper ones. There was association between increased stress vulnerability according to the OSVS and self-reported changes in feeding (p=0.028). The prevalence of high stress vulnerability increased (p = 0.034) with duration of employment (p = 0.034). Under self-reported stress, women had more hunger, changes in feeding, and preference for sweets (p < 0.001). Conclusions: The industrial workers showed prevalence of lower levels of stress vulnerability, with pressure at work representing the main stressor. Higher levels of stress vulnerability were associated with increased duration of employment as well as with the perception that work causes stress and interferes in feeding. The finding that, under a self-reported occupational stress condition, the prevalence of perceived change in feeding was higher among women, associated with increased hunger and preference for sweets, indicates a greater vulnerability of this group, with potential risks for health problems. Source

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