Otimização combinatória para alocação de fontes renováveis em microrredes de corrente contínua

Pós-graduação em Engenharia Elétrica - FEIS

Bending of Layer-by-Layer Films Driven by an External Magnetic Field

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

Modeling of piezoelectric energy harvesting considering the dependence of the rectifier circuit

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Eficiência de herbicidas no controle de plantas daninhas latifoliadas em mamona

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

Implementação de microrredes residenciais em corrente contínua através da microgeração

This paper discusses the importance of energy efficiency and the use of alternative energy sources, facing to the increasing energy demand and the concomitant economic, social and environmental restrictions imposed by society. In this work, alternative sources are illustrated by photovoltaic, micro turbines and fuel cells microgeneration systems. Energy efficiency is presented by direct current microgrids because its uses excludes the conversions of direct current (DC) to alternating current (AC) losses made with the intention of injecting energy into the electric grid and then the inverse conversion, AC to DC, in order to feed residential loads. The object of this paper is to analyze a case study and evaluates the costs and technical feasibility of a Project that combines a DC microgrid and a microgeneration system

Transmissão de potência em corrente contínua e em corrente alternada: estudo comparativo

This paper presents a comparative study based on literature and examples in the literature, the two main technologies for the transmission of electricity at high voltage: alternate current transmission and direct current transmission. Inside the direct current transmission will be shown two technologies currently employed, transmission by current source and transmission by voltage source, contributing to a better understanding of them. The ultimate goal is to provide a text for consultation to identify key characteristics that influence the choice of future transmission lines

Auxílio na tomada de decisão na compra de uma máquina de usinagem a laser

Decision making is one of the most important factors for growth and future, both from a business, as in people's life and attitudes in the simplest of everyday day. This work aims to assist decision making in buying a laser cut machine, a manufacturer of auto parts and wheels, and later this technique can be considered to acquisition of other equipment. In this case was used the AHP to aid the decision by multiple criteria. First we analyzed the most important criteria of the current machine for the application of the method and were later made the application and sensitivity analysis

Controle da população de morcegos hematófagos na região de Andradina, São Paulo

Pós-graduação em Ciência Animal - FMVA

A novel single-phase ZCS-PWM high power factor boost rectifier

This paper presents a novel single-phase high power factor PWM boost rectifier, featuring soft commutation of the active switches at zero-current (ZCS). It incorporates the most desirable properties of the conventional PWM and the soft-switching resonant techniques. The input current shaping is achieved with average current mode control, and continuous inductor current mode. This new PWM converter provides ZCS turn-on and turn-off of the active switches, and it is suitable for high power applications employing IGBTs. Principle of operation, theoretical analysis, a design example, and experimental results from a laboratory prototype rated at 1600 W with 400 Vdc output voltage are presented. The measured efficiency and power factor were 96.2% and 0.99 respectively, with an input current THD equal to 3.94%, for an input voltage THD equal to 3.8%, at rated load.

Ações educativas para o controle de vetores da dengue e leishmaniose visceral

Results of educative actions on the control of vectors for dengue and leishmaniasis were evaluated by using an online semi-present course directed to teachers from Fundamental I Education level in Araçatuba-SP. 40 teachers from municipal schools located on geographical areas of town with higher occurrence of dengue and leishmaniasis cases, attended to the course, which consisted in a conceptual part directed to specific subjects such as vector borne and zoonotic diseases, responsible ownership of pets and health education and a practical phase, directed to execution and application of educative projects in the target schools. Data about the teacher’s specific knowledge, before and after the attendance to the course, were submitted to the Wilcoxon test with a 5% of significant level. The application of practical educative projects was evaluated by multiplicative actions involving target public. Tests showed statistically significant increase in the knowledge about the studied diseases (p<0.0001) after the course, especially on questions related to etiological agent, clinical symptoms on man and animals and prevention. Activities of knowledge multiplication envolved teachers and students which detected the problems and promoted education actions in their neighborhood as stage performing, group cleaning activities and elaboration and distribution of folders during a student pared. In conclusion, educative actions direct to the control of diseases vectors using a semi-present course, provides new knowledge to the teachers, impelling them to motivate their students to adopt vectors control measures and environmental cares and to sensitive the community to collaborate with control diseases.

Análise dinâmica não-linear de um sistema não-ideal, utilizando amortecedor magneto-reológico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

High current-density anodic electro-dissolution in flow-injection systems for the determination of aluminium, copper and zinc in non-ferroalloys by flame atomic absorption spectrometry

An automatic Procedure with a high current-density anodic electrodissolution unit (HDAE) is proposed for the determination of aluminium, copper and zinc in non-ferroalloys by flame atonic absorption spectrometry, based on the direct solid analysis. It consists of solenoid valve-based commutation in a flow-injection system for on-line sample electro-dissolution and calibration with one multi-element standard, an electrolytic cell equipped with two electrodes (a silver needle acts as cathode, and sample as anode), and an intelligent unit. The latter is assembled in a PC-compatible microcomputer for instrument control, and far data acquisition and processing. General management of the process is achieved by use of software written in Pascal. Electrolyte compositions, flow rates, commutation times, applied current and electrolysis time mere investigated. A 0.5 mol l(-1) HNO3 solution was elected as electrolyte and 300 A/cm(2) as the continuous current pulse. The performance of the proposed system was evaluated by analysing aluminium in Al-allay samples, and copper/zinc in brass and bronze samples, respectively. The system handles about 50 samples per hour. Results are precise (R.S.D < 2%) and in agreement with those obtained by ICP-AES and spectrophotometry at a 95% confidence level.

A low-cost neurostimulator with accurate pulsed-current control

A constant-current stimulator for high-impedance loads using only low-cost standard high-voltage components Is presented. A voltage-regulator powers an oscillator built across the primary of a step-up transformer whose secondary supplies, after rectification, the high voltage to a switched current-mirror in the driving stage. Adjusting the regulated voltage controls the pulsed-current intensity. A prototype produces stimulus of amplitude and pulsewidth within 0 less than or equal to I-skin less than or equal to 20 mA and 50 mus less than or equal to T-pulse less than or equal to 1 ms, respectively. Pulse-repetition spans from 1 Hz to 10 Hz. Worst case ripple is 3.7% at I-skin = 1 mA. Overall consumption is 5.6 W at I-skin = 20 mA.

Variable structure controller and observer applied to induction machine

This work will propose the control of an induction machine in field coordinates with imposed stator current based on theory of variable structure control and sliding mode. We describe the model of an induction machine in field coordinates with imposed stator current and we show the design of variable structure control and sliding mode to get a desirable dynamic performance of that plant. To estimate the inaccessible states we will use a state observer (estimator) based on field coordinates induction machine. We will present the results of simulations in any operation condition (start, speed reversal and load) and with parameters variation of the machine compared to a PI control scheme.