Desenvolvimento de um Controlador com DSP para um Motor CA de 30 kW para o CEPIUM

Dissertação de mestrado integrado em Engenharia Eletrónica Industrial e Computadores

Consumer Advisory Bulletin, Tips for Buying a Used Car, June 2007

The Attorney General’s Consumer Protection Division receives hundreds of calls and consumer complaints every year. Follow these tips to avoid unexpected expense and disappointments. This record is about: Tips for Buying a Used Car

Consumer Advisory Bulletin, Avoid Car-Title Loans, December 2005

The Attorney General’s Consumer Protection Division receives hundreds of calls and consumer complaints every year. Follow these tips to avoid unexpected expense and disappointments. This record is about: Avoid Car-Title Loans

Consumer Advisory Bulletin; Tips for Buying a Used Car, November 2009

The Attorney General’s Consumer Protection Division receives hundreds of calls and consumer complaints every year. Follow these tips to avoid unexpected expense and disappointments. This record is about: Tips for Buying a Used Car

Mechanisms of spindle positioning during "Caenorhabditis elgans" asymmetric cell division

Résumé : Le positionnement correct du fuseau mitotique est crucial pour les divisions cellulaires asymétriques, car il gouverne le contrôle spatial de la division cellulaire et assure la ségrégation adéquate des déterminants cellulaires. Malgré leur importance, les mécanismes contrôlant le positionnement du fuseau mitotique sont encore mal compris. Chez l'embryon au stade une-cellule du nématode Caenorhabditis elegans, le fuseau mitotique est positionné de manière asymétrique durant l'anaphase grâce à l'action de générateurs de force situés au cortex cellulaire, et dont la nature était jusqu'alors indéterminée. Ces générateurs de force corticaux exercent une traction sur les microtubules astraux et sont dépendants de deux protéines Gα et de leurs protéines associées. Cette thèse traite de la nature de la machinerie responsable pour la génération des forces de tractions, ainsi que de son lien avec les protéines Gα et associées. Nous avons combiné des expériences de coupure par faisceau laser du fuseau mitotique avec le contrôle temporel de l'inactivation de gènes ou de l'exposition à des produits pharmacologiques. De cette manière, nous avons établi que la dynéine, un moteur se déplaçant vers l'extrémité négative des microtubules, ainsi que la dynamique des microtubules, sont toutes deux requises pour la génération efficace des forces de tractions. Nous avons démontré que les protéines Gα et leurs protéines associées GPR-1/2 et LIN-5 interagissent in vivo avec LIS-1, un composant du complexe de la dynéine. De plus, nous avons découvert que les protéines Gα, GPR-1/2 et LIN-5 promeuvent la présence du complexe de la dynéine au cortex cellulaire. Nos résultats suggèrent un mécanisme par lequel les protéines Gα permettent le recrutement cortical de GPR-1/2 et LIN-5, assurant ainsi la présence de la dynéine au cortex. Conjointement avec la dynamique des microtubules, ce mécanisme permet la génération des forces de tractions afin d'obtenir une division cellulaire correcte. Comme les mécanismes contrôlant le positionnement du fuseau mitotique et les divisions cellulaires asymétriques sont conservés au cours de l'évolution, nous espérons que les mécanismes élucidés par ce travail sont d'importance générale pour la génération de la diversité cellulaire durant le développement. De plus, ces mécanismes pourraient être applicables à d'autres divisions asymétriques, comme celle des cellules souches, dont le disfonctionnement peut entraîner la génération de cellules cancéreuses. Abstract : Proper spindle positioning is crucial for asymmetric cell division, because it controls spatial aspects of cell division and the correct inheritance of cell-fate determinants. However, the mechanisms governing spindle positioning remain incompletely understood. In the Caenorhabditis elegans one-cell stage embryo, the spindle becomes asymmetrically positioned during anaphase through the action of as-yet unidentified cortical force generators that pull on astral microtubules and that depend on two Gα proteins and associated proteins. This thesis addresses the nature of the force generation machinery and the link with the Gα and associated proteins. By performing spindle-severing experiments following temporally restricted gene inactivation and drug exposure, we established that microtubule dynamics and the minus-end directed motor dynein are both required for generating efficient pulling forces. We discovered that the Gα proteins and their associated proteins GPR-1/2 and LIN-5 interact in vivo with LIS-1, a component of the dynein complex. Moreover, we uncovered that LIN-5, GPR-1/2 and the Gα proteins promote the presence of the dynein complex at the cell cortex. Our findings suggest a mechanism by which the Gα proteins enable GPR-1/2 and LIN-5 recruitment to the cortex, thus ensuring the presence of cortical dynein. Together with microtubule dynamics, this allows pulling forces to be exerted and proper cell division to be achieved. Because the mechanisms of spindle positioning and asymmetric cell division are conserved across evolution, we expect the underlying mechanism uncovered here to be of broad significance for the generation of cell diversity during development. Moreover, this mechanism could be relevant for other asymmetric cell divisions, such as stem cell divisions, whose dysfunction may lead to the generation of cancer cells.

Performance Characteristics of an Axial-Flux Solid-Rotor-Core Induction Motor

The integration of electric motors and industrial appliances such as pumps, fans, and compressors is rapidly increasing. For instance, the integration of an electric motor and a centrifugal pump provides cost savings and improved performance characteristics. Material cost savings are achieved when an electric motor is integrated into the shaft of a centrifugal pump, and the motor utilizes the bearings of the pump. This arrangement leads to a smaller configuration that occupies less floor space. The performance characteristics of a pump drive can be improved by using the variable-speed technology. This enables the full speed control of the drive and the absence of a mechanical gearbox and couplers. When using rotational speeds higher than those that can be directly achieved by the network frequency the structure of the rotor has to be mechanically durable. In this thesis the performance characteristics of an axial-flux solid-rotor-core induction motor are determined. The motor studied is a one-rotor-one-stator axial-flux induction motor, and thus, there is only one air-gap between the rotor and the stator. The motor was designed for higher rotational speeds, and therefore a good mechanical strength of the solid-rotor-core rotor is required to withstand the mechanical stresses. The construction of the rotor and the high rotational speeds together produce a feature, which is not typical of traditional induction motors: the dominating loss component of the motor is the rotor eddy current loss. In the case of a typical industrial induction motor instead the dominating loss component is the stator copper loss. In this thesis, several methods to decrease the rotor eddy current losses in the case of axial-flux induction motors are presented. A prototype motor with 45 kW output power at 6000 min-1 was designed and constructed for ascertaining the results obtained from the numerical FEM calculations. In general, this thesis concentrates on the methods for improving the electromagnetic properties of an axial-flux solid-rotor-core induction motor and examines the methods for decreasing the harmonic eddy currents of the rotor. The target is to improve the efficiency of the motor and to reach the efficiency standard of the present-day industrial induction motors equipped with laminated rotors.

Electric Motor and Frequency Converter Markets in Latin America and Especially in the Mining Industry of Chile

Latinalaisen Amerikan osuus maailmantaloudesta on pieni verrattuna sen maantieteelliseen kokoon, väkilukuun ja luonnonvaroihin. Aluetta pidetään kuitenkin yhtenä tulevaisuuden merkittävistä kasvumarkkinoista. Useissa Latinalaisen Amerikan maissa on teollisuutta, joka hyödyntää luonnonvaroja ja tuottaa raaka-aineita sekä kotimaan että ulkomaiden markkinoille. Tällaisia tyypillisiä teollisuudenaloja Latinalaisessa Amerikassa ovat kaivos- ja metsäteollisuus sekä öljyn ja maakaasun tuotanto. Näiden teollisuudenalojen tuotantolaitteiden ja koneiden valmistusta ei Latinalaisessa Amerikassa juurikaan ole. Ne tuodaan yleensä Pohjois-Amerikasta ja Euroopasta. Tässä diplomityössä tutkitaan sähkömoottorien ja taajuusmuuttajien markkinapotentiaalia Latinalaisessa Amerikassa. Tutkimuksessa perehdytään Latinalaisen Amerikan maiden kansantalouksien tilaan sekä arvioidaan sähkömoottorien ja taajuusmuuttajien markkinoiden kokoa tullitilastojen avulla. Chilen kaivosteollisuudessa arvioidaan olevan erityistä potentiaalia. Diplomityössä selvitetään ostoprosessin kulkua Chilen kaivosteollisuudessa ja eri asiakastyyppien roolia siinä sekä tärkeimpiä päätöskriteerejä toimittaja- ja teknologiavalinnoissa.

Position sensorless electrically excited synchronous motor drive for industrial use based on direct flux linkage and torque control

Synchronous machines with an AC converter are used mainly in large drives, for example in ship propulsion drives as well as in rolling mill drives in steel industry. These motors are used because of their high efficiency, high overload capacity and good performance in the field weakening area. Present day drives for electrically excited synchronous motors are equipped with position sensors. Most drives for electrically excited synchronous motors will be equipped with position sensors also in future. This kind of drives with good dynamics are mainly used in metal industry. Drives without a position sensor can be used e.g. in ship propulsion and in large pump and blower drives. Nowadays, these drives are equipped with a position sensor, too. The tendency is to avoid a position sensor if possible, since a sensor reduces the reliability of the drive and increases costs (latter is not very significant for large drives). A new control technique for a synchronous motor drive is a combination of the Direct Flux Linkage Control (DFLC) based on a voltage model and a supervising method (e.g. current model). This combination is called Direct Torque Control method (DTC). In the case of the position sensorless drive, the DTC can be implemented by using other supervising methods that keep the stator flux linkage origin centered. In this thesis, a method for the observation of the drift of the real stator flux linkage in the DTC drive is introduced. It is also shown how this method can be used as a supervising method that keeps the stator flux linkage origin centered in the case of the DTC. In the position sensorless case, a synchronous motor can be started up with the DTC control, when a method for the determination of the initial rotor position presented in this thesis is used. The load characteristics of such a drive are not very good at low rotational speeds. Furthermore, continuous operation at a zero speed and at a low rotational speed is not possible, which is partly due to the problems related to the flux linkage estimate. For operation in a low speed area, a stator current control method based on the DFLC modulator (DMCQ is presented. With the DMCC, it is possible to start up and operate a synchronous motor at a zero speed and at low rotational speeds in general. The DMCC is necessary in situations where high torque (e.g. nominal torque) is required at the starting moment, or if the motor runs several seconds at a zero speed or at a low speed range (up to 2 Hz). The behaviour of the described methods is shown with test results. The test results are presented for the direct flux linkage and torque controlled test drive system with a 14.5 kVA, four pole salient pole synchronous motor with a damper winding and electric excitation. The static accuracy of the drive is verified by measuring the torque in a static load operation, and the dynamics of the drive is proven in load transient tests. The performance of the drive concept presented in this work is sufficient e.g. for ship propulsion and for large pump drives. Furthermore, the developed methods are almost independent of the machine parameters.

Implicaciones psicopedag??gicas en el an??lisis de textos escolares: Editorial Anaya. Segundo Ciclo de Educaci??n General B??sica

Analizar los textos que corresponden a la segunda etapa de Educaci??n General B??sica (E.G.B.) de la editorial Anaya, para conocer hasta qu?? punto las editoriales contribuyen al perfeccionamiento del individuo teniendo en cuenta su proceso evolutivo. 12 libros de la segunda etapa de E.G.B de la editorial Anaya. Explica una serie de conceptos relacionados con el desarrollo psicol??gico evolutivo del ni??o, despu??s analiza el contenido de los textos de E.G.B. por cursos y por categor??as psicol??gicas y ofrece los resultados obtenidos del an??lisis, concluyendo el estudio con unas implicaciones psicopedag??gicas. Gr??ficos. Realiza unos cuadros explicativos con los textos de cada curso y con los siguientes conceptos: sensibilizaci??n, atenci??n, memoria, imaginaci??n, lenguaje, inteligencia y creatividad. Despu??s se halla el n??mero de frecuencias de repetici??n de conceptos, consiguiendo despu??s el tanto por ciento con respecto al n??mero de p??ginas examinadas. Posteriormente se realizan las gr??ficas en las cuales aparecen representados los datos. 1) Los textos de quinto curso desarrollan los temas de atenci??n y lenguaje ampliamente, el concepto de inteligencia se recoge en un 47 por 100, mientras que las dem??s categor??as est??n poco desarrolladas, ya que no superan el 20 por 100, y en el caso de la sensibilidad, ??sta no alcanza ni siquiera el 5 por 100. 2) Los conceptos que m??s ampliamente han sido desarrollados en sexto curso corresponden a la atenci??n que alcanza el 100 por ciento, le siguen el lenguaje con un 87 por 100 y la motricidad con un 78 por 100. Las dem??s se encuentran por debajo del 50 por 100, la inteligencia con un 47 por 100, la creatividad llega al 33 por 100, mientras que la memoria y la sensibilidad apenas alcanzan el 5 por cien. 3) En el s??ptimo curso, los textos desarrollan la atenci??n, la motricidad, el lenguaje y la inteligencia en un porcentaje superior al 50 por 100, mientras que las dem??s categor??as est??n muy por debajo del 10 por 100 y no son muy significativas, salvo la creatividad que a??n siendo pobre su tratamiento, alcanza el 32 por 100. 4) En octavo curso, las capacidades m??s desarrolladas son la atenci??n con un 100 por ciento y el lenguaje con un 91 por 100. La inteligencia se halla desarrollada tan s??lo en un 26 por 100, mientras que las dem??s est??n muy por debajo. 1) La sensibilidad apenas es tratada en los textos, sin embargo es una capacidad que conviene desarrollar en todos sus aspectos, tanto la general, como la sensorial, porque en su conjunto constituye la llave del conocimiento. 2) La motricidad que se desarrolla en los textos, no es otra que la motricidad manual, sin embargo apenas se desarrolla la motricidad general, aunque en esta etapa no hay desarrollo motriz sino perfeccionamiento motor. 3) La atenci??n es el concepto que m??s fuertemente se encuentra desarrollado en los textos, pero para lograr el m??ximo desarrollo hay que tener en cuenta el tipo de est??mulos presentados al muchacho y la forma en que ??stos se encuentran organizados. 4) La memoria es primordial para la adquisici??n de conocimientos. Sin embargo, dicha adquisici??n no debe convertirse en pura repetici??n mec??nica de lo aprendido, sino que debe hacer una comprensi??n de aquello que se va a aprender. 5) La imaginaci??n se halla escasamente dotada en los textos analizados, por lo que las editoriales deber??an ayudar a los chicos a desarrollar esta capacidad, pero siempre basando las im??genes en objetos y cosas reales. 6) El desarrollo del lenguaje est?? favorecido en los textos de una forma positiva, puesto que es un concepto muy importante. 7) Cuando la creatividad est?? desarrollada, el muchacho puede expresarse con mayor libertad, aportando al trabajo un car??cter personal que redundar??a en aumento, no s??lo en los resultados obtenidos, sino tambi??n en la aplicaci??n del sujeto, que realizar?? las cosas no por imposici??n, sino porque le atraen.

Análise do desempenho de um gerador elétrico de pequeno porte acionado a motor de combustão a quatro tempos

Pós-graduação em Engenharia Mecânica - FEG

Virtopsy--fatal motor vehicle accident with head injury.

A man wearing no protective helmet was struck by a motor vehicle while riding a bicycle. He was loaded on his left side, and the impact point of his head was his occiput on the car roof girder. He was immediately transported to the general hospital, where he passed away. Postmortem examination using multi-slice computed tomography (MSCT) revealed an extensively comminuted fracture of the posterior part and the base of the skull. Observed were deep direct and contrecoup brain bruises, with the independent fractures of the roof of the both orbits. Massive subdural and subarachnoidal hemorrhage with cerebral edema and shifting of the mid-line towards left side were also detected. MSCT and autopsy results were compared and the body injuries were correlated to vehicle damages. In conclusion, postmortem imaging is a good forensic visualization tool with great potential for documentation and examination of body injuries and pathology.

Transfer Pricing in the Decentralized Multinational Corporation

This paper considers how the multinational corporation's transfer price responds to changes in international corporate effective tax rates. It extends the decentralized decision-making analysis of transfer pricing in the context of different tax rates. It adopts and extends Bond's (1980) model of the decentralized multinational corporation that assumes centralized transfer pricing. The direction of transfer price change is as expected, while the magnitude of change is likely to be less than predicted by the Horst (1971), centralized decision-making model. The paper extends the model further by assuming negotiated transfer pricing, where the analysis is partitioned into perfect and imperfect information cases. The negotiated transfer pricing result reverts to the Horst (1971), or centralized decision-making, result, under perfect information. Under imperfect information, the centralized decision-making result obtains when top management successfully informs division general managers or it successfully implements a non-monetary reward scheme to encourage division general managers to cooperate. Under simplifying assumptions, centralized decision-making dominates decentralized decision-making, while negotiated transfer pricing weakly dominates centralized transfer pricing.

Sistema para cambiar la geometría de un motor

En este proyecto se desarrolla un sistema electrónico para variar la geometría de un motor de un monoplaza que participa en la competición Fórmula SAE. Fórmula SAE es una competición de diseño de monoplazas para estudiantes, organizado por “Society of Automotive Enginners” (SAE). Este concurso busca la innovación tecnológica de la automoción, así como que estudiantes participen en un trabajo real, en el cual el objetivo es obtener resultados competitivos cumpliendo con una serie de requisitos. La variación de la geometría de un motor en un vehículo permite mejorar el rendimiento del monoplaza consiguiendo elevar el par de potencia del motor. Cualquier mejora en del vehículo en un ámbito de competición puede resultar determinante en el desenlace de la misma. El objetivo del proyecto es realizar esta variación mediante el control de la longitud de los tubos de admisión de aire o “runners” del motor de combustión, empleando un motor lineal paso a paso. A partir de la información obtenida por sensores de revoluciones del motor de combustión y la posición del acelerador se debe controlar la distancia de dichos tubos. Integrando este sistema en el bus CAN del vehículo para que comparta la información medida al resto de módulos. Por todo esto se realiza un estudio aclarando los aspectos generales del objetivo del trabajo, para la comprensión del proyecto a realizar, las posibilidades de realización y adquisición de conocimientos para un mejor desarrollo. Se presenta una solución basada en el control del motor lineal paso a paso mediante el microcontrolador PIC32MX795F512-L. Dispositivo del fabricante Microchip con una arquitectura de 32 bits. Este dispone de un módulo CAN integrado y distintos periféricos que se emplean en la medición de los sensores y actuación sobre el motor paso a paso empleando el driver de Texas Instruments DRV8805. Entonces el trabajo se realiza en dos líneas, una parte software de programación del control del sistema, empleando el software de Microchip MPLABX IDE y otra parte hardware de diseño de una PCB y circuitos acondicionadores para la conexión del microcontrolador, con los sensores, driver, motor paso a paso y bus CAN. El software empleado para la realización de la PCB es Orcad9.2/Layout. Para la evaluación de las medidas obtenidas por los sensores y la comprobación del bus CAN se emplea el kit de desarrollo de Microchip, MCP2515 CAN Bus Monitor Demo Board, que permite ver la información en el bus CAN e introducir tramas al mismo. ABSTRACT. This project develops an electronic system to vary the geometry of a car engine which runs the Formula SAE competition. Formula SAE is a design car competition for students, organized by "Society of Automotive Engineers" (SAE). This competition seeks technological innovation in the automotive industry and brings in students to participate in a real job, in which the objective is to obtain competitive results in compliance with certain requirements. Varying engine’s geometry in a vehicle improves car’s performance raising engine output torque. Any improvement in the vehicle in a competition field can be decisive in the outcome of it. The goal of the project is the variation by controlling the length of the air intake pipe or "runners" in a combustion engine, using a linear motor step. For these, uses the information gathered by speed sensors from the combustion engine and by the throttle position to control the distance of these tubes. This system is integrated in the vehicle CAN bus to share the information with the other modules. For all this is made a study to clarify the general aspects of the project in order to understand the activities developed inside the project, the different options available and also, to acquire knowledge for a better development of the project. The solution is based on linear stepper motor control by the microcontroller PIC32MX795F512-L. Device from manufacturer Microchip with a 32-bit architecture. This module has an integrated CAN various peripherals that are used in measuring the performance of the sensors and drives the stepper motor using Texas Instruments DRV8805 driver. Then the work is done in two lines, first, control programming software system using software MPLABX Microchip IDE and, second, hardware design of a PCB and conditioning circuits for connecting the microcontroller, with sensors, driver stepper motor and CAN bus. The software used to carry out the PCB is Orcad9.2/Layout. For the evaluation of the measurements obtained by the sensors and CAN bus checking is used Microchip development kit, MCP2515 CAN Bus Monitor Demo Board, that allows you to see the information on the CAN bus and enter new frames in the bus.

Characterization of the KIF3C Neural Kinesin-like Motor from Mouse

Proteins of the kinesin superfamily define a class of microtubule-dependent motors that play crucial roles in cell division and intracellular transport. To study the molecular mechanism of axonal transport, a cDNA encoding a new kinesin-like protein called KIF3C was cloned from a mouse brain cDNA library. Sequence and secondary structure analysis revealed that KIF3C is a member of the KIF3 family. In contrast to KIF3A and KIF3B, Northern and Western analysis indicated that KIF3C expression is highly enriched in neural tissues such as brain, spinal cord, and retina. When anti-KIF3C antibodies were used to stain the cerebellum, the strongest signal came from the cell bodies and dendrites of Purkinje cells. In retina, anti-KIF3C mainly stains the ganglion cells. Immunolocalization showed that the KIF3C motor in spinal cord and sciatic nerve is mainly localized in cytoplasm. In spinal cord, the KIF3C staining was punctate; double labeling with anti-giantin and anti-KIF3C showed a clear concentration of the motor protein in the Golgi complex. Staining of ligated sciatic nerves demonstrated that the KIF3C motor accumulated at the proximal side of the ligated nerve, which suggests that KIF3C is an anterograde motor. Immunoprecipitation experiments revealed that KIF3C and KIF3A, but not KIF3B, were coprecipitated. These data, combined with previous data from other labs, indicate that KIF3C and KIF3B are “variable” subunits that associate with a common KIF3A subunit, but not with each other. Together these results suggest that KIF3 family members combinatorially associate to power anterograde axonal transport.

Going mobile: microtubule motors and chromosome segregation.

Proper chromosome segregation in eukaryotes depends upon the mitotic and meiotic spindles, which assemble at the time of cell division and then disassemble upon its completion. These spindles are composed in large part of microtubules, which either generate force by controlled polymerization and depolymerization or transduce force generated by molecular microtubule motors. In this review, we discuss recent insights into chromosome segregation mechanisms gained from the analyses of force generation during meiosis and mitosis. These analyses have demonstrated that members of the kinesin superfamily and the dynein family are essential in all organisms for proper chromosome and spindle behavior. It is also apparent that forces generated by microtubule polymerization and depolymerization are capable of generating forces sufficient for chromosome movement in vitro; whether they do so in vivo is as yet unclear. An important realization that has emerged is that some spindle activities can be accomplished by more than one motor so that functional redundancy is evident. In addition, some meiotic or mitotic movements apparently occur through the cooperative action of independent semiredundant processes. Finally, the molecular characterization of kinesin-related proteins has revealed that variations both in primary sequence and in associations with other proteins can produce motor complexes that may use a variety of mechanisms to transduce force in association with microtubules. Much remains to be learned about the regulation of these activities and the coordination of opposing and cooperative events involved in chromosome segregation; this set of problems represents one of the most important future frontiers of research.