979 resultados para three-phase four-wire


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Pós-graduação em Agronomia (Agricultura) - FCA

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Background: The use of all by-products of bovine slaughter is of high economic importance for the industries of products of animal origin. Among these products, fat has an important role, once fat rendering may generate several different products, such as protein material that may be used in the manufacture of meat products. However, in spite of the importance that the use of all by-products has for the economic balance of the industry, there are no reports on their use in Brazil, or studies that supply data on microbiological and physical-chemical local standards for this protein. Thus, the objective of this study was to evaluate microbiological and physical-chemical characteristics of protein material obtained from fat rendering, as well as to provide support for companies to use fat rendering to generate protein material, adding value to industrialized meat products.Materials, Methods & Results: The experimental production of edible protein obtained of fat rendering was conducted in slaughterhouse with supervision of the Brazilian Ministry of Agriculture, Livestock and Food Supply. Protein material was obtained in a continuous, humid heat system at high temperatures. Fat scraps containing protein were ground and cooked at high temperature (85 degrees C), and placed in a three phase decanter centrifuge. After centrifugation, protein material was ground again and packed. Samples were collected from 15 batches of protein material, and the following microbiological analyses were carried out: counts of aerobic mesophilic and psychrotrophic microorganisms, coliforms at 35 degrees C, Escherichia coli, sulfite-reducing Clostridium, and Staphylococcus aureus, besides presence or absence of Salmonella and Listeria monocytogens. The following physical-chemical analyses were also carried out: protein, total lipid, moisture, ash, carbohydrate, and energy content. Mean counts of mesophiles, psychrotrophs, and coliforms at 35 degrees C were 4.17; 3.69 and 1.87 (log CFU/g), respectively. Levels of protein, total lipids, moisture, ashes and carbohydrates were 27.50; 7.83; 63.88%; 0.24%; and 0.55%, respectively, and energy content was 182.63 kcal/100g.Discussion: Results of microbiological analyses demonstrated that, although low, the final product showed to be contaminated. Contamination that occurred during the second grinding procedure may be an explanation for these bacterial counts. Also, the temperature used for fat fusion was not enough to eliminate thermoduric microorganisms. However, even with the presence of indicator microorganisms in the samples, none was contaminated by E. coli, sulfite-reducing Clostridium, S. aureus, Salmonella or L. monocytogenes. Physical-chemical analyses showed that the product had adequate nutritional quality. Based on these results, it was possible to conclude that protein material obtained in fat rendering showed characteristics that enable the use of this product as raw material for processed meat products. Besides, the present study was the first one to present scientific results in relation to edible by-products obtained in fat rendering, supplying important information for slaughterhouses and meat-processing plants. The study also produced relevant data on the innocuousness of the product, which may be used to guide decision-making of health inspectors.

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Background: The sandwich technique is an endovascular off-the-shelf solution for patients with thoracoabdominal aortic aneurysms (TAAAs). In a sandwich configuration, the chimney stent runs in the middle of a space created by two or three aortic endografts.Methods: All patients with TAAAs who were treated with the sandwich technique were included in the study. Self-expanding Viabahn grafts (W. L. Gore and Associates Inc, Flagstaff, Ariz) were used as parallel grafts in the renal arteries and visceral vessels. Caudad-facing chimney grafts were used for the visceral arteries and cephalad-facing periscope grafts for the renal arteries.Results: During the study period, 32 patients with TAAAs were treated with sandwich grafts. Indication for the procedure in 43% was an acute onset of symptoms, including two patients with a rupture and a retroperitoneal hematoma. Three patients required an additional debranching procedure. A total of 104 chimney grafts were implanted. Two patients died postoperatively because of the operation. Major adverse events were recorded in five patients, including one patient with persistent paraplegia and two with permanent renal failure requiring dialysis. The incidence of chimney graft occlusion was higher in patients with three or four parallel grafts than in those with two chimney grafts only. Patients with chronic dissections had a 12-times higher incidence of chimney graft occlusion than aneurysm patients. The number of patients with type I or III endoleaks was higher in the group with three or four parallel grafts.Conclusions: The sandwich technique is an off-the-shelf endovascular alternative to treat patients with TAAAs in an emergent setting. The combination of chimney grafts with a periscope configuration enables a rapid endovascular aneurysm exclusion with acceptable midterm results.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Objective: Although previous studies have analyzed the association between cardiovascular risk factors and blood pressure in adolescents, few studies conducted in developing countries analyzed whether the aggregation of risk factors contributes to an increased risk of high blood pressure in adolescents. The objective of this study was to assess the association between cardiovascular risk factors (including general overweight, abdominal obesity, high consumption of foods rich in fats, and insufficient physical activity levels) and high blood pressure in adolescents.Methods: This study was carried out from 2007 to 2008 with 1021 adolescents (528 girls) from primary schools located in the city of Londrina- Brazil. Blood pressure was assessed using an oscillometric device. General overweight was obtained through body mass index, abdominal obesity was assessed using waist circumference, and the consumption of foods rich in fat and physical activity were assessed using a questionnaire. The sum of these risk factors was determined.Results: Adolescents with three or four aggregated risk factors were more likely to have higher values of systolic and diastolic blood pressure when compared with adolescents who did not have any cardiovascular risk factors (P = 0.001 for both). Logistic regression indicated that groups of adolescents with 2 (OR = 2.46 [1.11-5.42]; P = 0.026), 3 (OR = 4.97 [2.07-11.92]; P = 0.001) or 4 risk factors (OR = 6.79 [2.24-19.9]; P = 0.001) presented an increased likelihood of high blood pressure.Conclusions: The number of cardiovascular risk factors was found to be related to high blood pressure in adolescents. (C) 2014 Wiley Periodicals, Inc.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Pós-graduação em Engenharia Elétrica - FEB

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The purpose of this paper is to present the application of a three-phase harmonic propagation analysis time-domain tool, using the Norton model to approach the modeling of non-linear loads, making the harmonics currents flow more appropriate to the operation analysis and to the influence of mitigation elements analysis. This software makes it possible to obtain results closer to the real distribution network, considering voltages unbalances, currents imbalances and the application of mitigation elements for harmonic distortions. In this scenario, a real case study with network data and equipments connected to the network will be presented, as well as the modeling of non-linear loads based on real data obtained from some PCCs (Points of Common Coupling) of interests for a distribution company.

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This paper aims to show practical and effectiveexperiencesfor lessons Industrial Automation Laboratory taught inundergraduate degreein ElectricalEngineering from the University Júlio MesquitaFilho - UNESP, Guaratinguetá. Experiments carriedsimulatecontrol and drive systems of electric three phase induction motors (MIT)widely usedinindustries. The experiments simulate a manufacturing environment where there isa need to control the activation and continuous operation ofelectricmotors. Seven experimentsthat simulatethe firing of electrical motors through a controlsystem, a driver along with asimulator loads coupled to the electric motor was developed. Experiments usinga Programmable Logic Controller (PLC) as acontroller,an inverter frequencyasdriver, and MagneticBrake, as simulatorengine loads . The experiments were divided accordingto the speed reference signal used fordrivingand operating the electric motor: digital and analog. The first five experiments performing the drive control and operation of the electric motor via digital signals. The sixth and seventh experiments using an analog signal as a reference speed for the electric motor

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This work aims to make the closed loop control of a three phase induction motor, through the integration of the following equipment: a frequency inverter, the actuator system; a programmable logic controller (PLC), the controller; an encoder, the velocity sensor, used as a feedback monitoring the control variable and the three-phase induction motor, the plant to be controlled. The control is performed using a Proportional - Integrative - Derivative (PID) approach. The PLC has a help instruction, which performs the auto adjustment of the controller, that instruction is used and confronted with other adjustment methods. There are several types of methods adjustments to the PID controllers, where the empirical methods are addressed in this work. The system is deployed at the Interface and Electro Electronic Control laboratory in the Universidade Estadual Paulista Júlio Mesquita Filho, Guaratinguetá, São Paulo, then, in the future, this work becomes an experiment to be conducted in the classroom, allowing undergraduate students to develop a greater affinity to the programs used by the PLC as well as studies of undergraduate and graduate works with the help of assembly made

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Large electric motors require greater care when driving, especially during continuous operation since they are part of day-to-day manufacturing sector, acting essentially to ensure that no damage occurs to the production process and equipment that are part of the same system. This work includes the analysis of electrical protection in a system comprised of a three phase induction motor driven by a frequency converter as well as an analysis of the functions of a multifunction electronic relay. It is presented a comparison between the existing functions in a converter and a relay and a real case is described in order to exemplify the use of an electric motor and features that are aimed at their protection, and the system in which it is inserted. Based on the results, it is of great importance in this field of performance studies, generating relevant results, which may be exposed in order to unify into a single document, different sources of information that are arranged randomly, improve utilization motor and extend the life of equipment forming part of the electrical installation

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This paper proposes the conversion of a three-phase induction motor into single phase through rewinding its stator. It presents a methodology to calculate this rewinding process considering the constructive parameters of the, such as number of slots and number of poles, for instance. The operating principles of DC motors are highlighted to introduce the logic involved in the calculation of lap and wave windings. The construction of the stator three-phase induction motor generally uses the lap winding, which is also used in single phase to perform the conversion. The rewinding process is widely used for reconstruction of industrial and residential electric motors that have suffered damage or present flaws with use. Therefore, many three-phase electric motors that are discarded or disposed of could be recovered by the method described in this work for a purpose that contributes to energy efficiency or simply saving resources in single-phase uses