Este trabalho propõe analisar o desempenho de redes de comunicação industrial em aplicações de acionamentos de motores elétricos trifásicos. Compara-se o desempenho da tecnologia Profibus DP em relação à Profinet. O desempenho é verificado a partir de especificações técnicas de ambos protocolos e experimentos práticos para coleta de dados e análise dos seguintes indicadores de desempenho: tempo de ciclo, jitter e ocupação de largura de banda. Adicionalmente, é verificado o desempenho de uma aplicação de controle de posição, utilizando estes protocolos na malha de controle, através do tempo de acomodação do sistema. Conclusões mostram que a rede Profibus DPV0 é a mais rápida quando possui menos dispositivos, porém o Profinet RT consegue manter baixos valores de tempo de ciclo mesmo com grande quantidade de dispositivos e possui maior determinismo na topologia em barramento. No que diz respeito ao controle de posição estudado, as tecnologias apresentam desempenho similar para tempo de acomodação do sistema, porém o Profinet IRT foi o mais determinístico. / This work proposes a performance analysis of industrial communication networks in applications of electric AC motor drives. It compares the performance of Profibus DP technology in relation to Profinet. Performance is verified from technical specifications of both protocols and practical experiments for data collection and analysis of the following performance indicators: cycle time, jitter and bandwidth occupation. Additionally, the performance of a motion control application is verified, by using these protocols in the loop control, through the settling time of the system. Conclusions show that Profibus DPV0 is faster when there is less devices in the network, but Profinet RT manages to maintain low values of cycle time even with large number of devices and has higher determinism when installed in line topology. Regarding the motion control application studied, the technologies have similar settling time for the system performance, but the Profinet IRT was more deterministic.

O elemento químico neodímio (Nd) atualmente está em evidência pois é parte fundamental em aplicações produzidas por empresas ligadas a tecnologias limpas e de ponta. Porém, é classificado como crítico pelo departamento de energia dos EUA em função do monopólio chinês atuante em sua exploração e comercialização. Devido à crescente demanda frente à restrita disponibilidade, a recuperação deste metal está em ascensão. Uma das aplicações do neodímio é o ímã permanente de neodímio-ferro-boro, utilizado em hard disk drives (HDs) de computadores. Desta forma, este estudo visou caracterizar os ímãs provenientes de HDs de computadores e estabelecer uma rota de recuperação do neodímio por meio de processos mecânicos e hidrometalúrgicos. Por meio da pesagem dos HDs e seus ímãs obteve-se massa média de 3,04 g e 7,91 g para laptop e desktop, respectivamente, representando menos de 3% da massa total do HD. A desmagnetização foi atingida por meio de aquecimento até a temperatura de Curie, em torno de 312 °C, e a cominuição realizada em moinho de facas, onde foram obtidas três granulometrias classificadas em frações A, B e C. Qualitativamente as amostras, foram analisados por meio de difração de raios-X (DRX), onde a fase tetragonal Nd2Fe14B foi o constituinte dominante, e por meio de análise em microscópio eletrônico de varredura (MEV). Semi-quantitativamente os ímãs, seus revestimentos e o precipitado final foram avaliados por meio de espectrometria de fluorescência de raios-X (FRX). A composição média de 21,5% de neodímio e 65,1% de ferro em massa, além de outros elementos químicos, obtida por meio de espectrometria de emissão óptica com plasma (ICP-OES), mostrou teor de neodímio superior aos minérios explorados, tornando este resíduo interessante em relação à recuperação deste metal. O procedimento hidrometalúrgico adotado envolveu a lixiviação das amostras em ácido sulfúrico 2M e a variação de três parâmetros: razão sólido/líquido, temperatura e tempo, em dois níveis. Posteriormente foi realizada a precipitação seletiva por meio de NaOH, formando o duplo sal NaNd(SO4)2.nH2O. Os resultados mostraram que a lixiviação de neodímio atingiu eficiência média acima de 94%, porém todos os experimentos apresentaram material não lixiviado, majoritariamente composto por níquel e cobre. / The chemical element neodymium (Nd) currently is in evidence as it is a fundamental part in applications manufactured by clean and advanced technology companies. However, it is classified as critical by the United States Department of Energy due to Chinese monopoly in its exploration and commercialization. Due to increasing demand in contrast with scarce supply, the recovery of neodymium is growing. One of the applications of this metal is the neodymium-iron-boron permanent magnet, used in hard disk drives (HDDs) of computers. Therefore, this study aimed magnets characterizing from HDDs of computers and then establishing a recovery route for neodymium by mechanical and hydrometallurgical processes. By weighing the HDDs and their magnets it was obtained the average weight of 3.04 g and 7.91 g for laptop and desktop, respectively, representing less than 3% of the HDDs total mass. Demagnetizing was achieved by heating up to Curie temperature of around 312 °C, and the comminution in knives mill resulted in three granulometries classified into fractions A, B and C. Qualitatively, magnets were analyzed by X-ray diffraction (XRD), where the tetragonal phase Nd2Fe14B was the dominant constituent of the sample, and through analysis in a scanning electron microscope (SEM). Semi-quantitatively, the magnets, its covers, and the final precipitate were evaluated by X-ray fluorescence spectrometry (XRF). The average composition of neodymium and iron showed 21.5% and 65.1% by weight, respectively, among other chemical elements. This results were obtained by optical emission spectrometry (ICP-OES), representing a higher neodymium content compared to the ores content, which makes this waste interesting from a neodymium recovery point of view. The procedure adopted involved hydrometallurgical leaching of the samples in 2M sulfuric acid varying three parameters: liquid/solid ratio, temperature and time, each one on two levels. Subsequently, the selective precipitation by NaOH was performed to form the double salt NaNd(SO4)2.nH2O. The results showed that neodymium leaching efficiency reached above 94%, but the experiments showed as well some material left, mainly composed of nickel and copper.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1981. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Bibliography: leaves 109-110. / by Tim Emmanuel Bliamptis. / M.S.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Este trabalho aborda os efeitos de afundamentos de tensÃo em Acionamentos de Velocidade VariÃvel â AVVs para mÃquinas de corrente alternada, conversores estÃticos de dois estÃgios (retificador-inversor) amplamente utilizados no controle de velocidade e traÃÃo. O estudo tem como objetivo analisar o comportamento dos AVVs diante de afundamentos de tensÃo simÃtricos e assimÃtricos e tÃcnicas de aumento de suportabilidade para estes equipamentos, destacando-se o uso de conversores boost. SÃo apresentados resultados de simulaÃÃes computacionais e de ensaios laboratoriais de um conversor boost desenvolvido para aumentar a tolerÃncia de AVV a afundamentos de tensÃo. Nos ensaios de laboratÃrio foram levantadas as curvas de tolerÃncia do AVV para afundamentos de tensÃo dos tipos A, B e E e comparadas aos limites estabelecidos pela curva SEMI F47 0706 do instituto EPRI. O AVV mostrou-se sensÃvel aos afundamentos tipo A e E com imunidade de tensÃo remanescente de atà 0,7pu na barra CC do AVV. Foram ainda feitos ensaios experimentais com o conversor boost conectado ao AVV sob condiÃÃes de afundamentos de tensÃo severos dos tipos A e E. A anÃlise do conjunto AVV-MIT sob os demais tipos de afundamentos de tensÃo (B, C, D, F e G) foi feita por simulaÃÃo computacional usando um modelo previamente validado pela comparaÃÃo com os resultados experimentais. Os afundamentos dos tipos A, E, F e G, que podem provocar o desligamento do AVV, foram tambÃm analisados por simulaÃÃes computacionais com a conexÃo do conversor boost ao barramento CC do AVV. Para a avaliaÃÃo do comportamento do AVV com e sem o conversor boost foram obtidas as curvas de tensÃo do barramento CC, tensÃo de saÃda do AVV, tensÃo de entrada do conversor boost, e de correntes de entrada do AVV, do conversor boost e de saÃda da fonte. Conforme os resultados de simulaÃÃes e experimentais o conversor boost pode mitigar afundamentos do tipo A para atà 0,5pu e todos os outros tipos de afundamentos atà nÃveis de interrupÃÃo, isto Ã, 0pu. Comparados os resultados com as simulaÃÃes de outras soluÃÃes abordadas no trabalho, o conversor boost se mostrou como a melhor alternativa do ponto de vista tÃcnico. / This work investigates the effects of voltage sags on Adjustable Speed Drives â ASDs of AC machines, static converters of two stages (rectifier-inverter) widely used on speed and torque control. The goal is to analyse the behavior of the ASDs under symmetrical and asymmetrical voltage sags and the approaches to improve the ASD low voltage ride-through capability with emphasis to the boost converter technique. Computational simulations and experimental results of a boost converter designed to operate when the ASD is under voltage sags are presented. The tolerance curves of the ASD were obtained in laboratory for voltage sags types A, B and E and compared to the SEMI F47 0706 curve of the EPRI institute. The ASD was shown sensitive for voltage sags types A and E with immunity for remaining voltages up to 0.7pu on the DC link. Experimental tests were performed to evaluate the response of the boost converter operation when the ASD is under severe voltage sag conditions of types A and E. The set ASD-induction motor was modelled for the simulation tests and the model validation was performed by comparison with experimental results. The analysis of the ASD and the three-phase induction motor under voltage sags B, C, D, F e G were carried out by computational simulations. The voltage sag types A, E, F and G which can turn off the ASD were also analyzed by computational simulation with the boost converter connected to ASD DC bus. The curves of DC link voltage, the ASD output voltage, the boost input voltage and the input currents of the ASD, the boost converter and the source were plotted for evaluation of the ASD behavior with and without the boost converter. The simulation and experimental results have shown that the boost converter can mitigate voltage sags type A up to 0.5pu and all other types of voltage sags up to 0pu. The boost converter has proved a suitable solution to improve the ASD voltage sag ride through capability.

Este trabalho propõe analisar o desempenho de redes de comunicação industrial em aplicações de acionamentos de motores elétricos trifásicos. Compara-se o desempenho da tecnologia Profibus DP em relação à Profinet. O desempenho é verificado a partir de especificações técnicas de ambos protocolos e experimentos práticos para coleta de dados e análise dos seguintes indicadores de desempenho: tempo de ciclo, jitter e ocupação de largura de banda. Adicionalmente, é verificado o desempenho de uma aplicação de controle de posição, utilizando estes protocolos na malha de controle, através do tempo de acomodação do sistema. Conclusões mostram que a rede Profibus DPV0 é a mais rápida quando possui menos dispositivos, porém o Profinet RT consegue manter baixos valores de tempo de ciclo mesmo com grande quantidade de dispositivos e possui maior determinismo na topologia em barramento. No que diz respeito ao controle de posição estudado, as tecnologias apresentam desempenho similar para tempo de acomodação do sistema, porém o Profinet IRT foi o mais determinístico. / This work proposes a performance analysis of industrial communication networks in applications of electric AC motor drives. It compares the performance of Profibus DP technology in relation to Profinet. Performance is verified from technical specifications of both protocols and practical experiments for data collection and analysis of the following performance indicators: cycle time, jitter and bandwidth occupation. Additionally, the performance of a motion control application is verified, by using these protocols in the loop control, through the settling time of the system. Conclusions show that Profibus DPV0 is faster when there is less devices in the network, but Profinet RT manages to maintain low values of cycle time even with large number of devices and has higher determinism when installed in line topology. Regarding the motion control application studied, the technologies have similar settling time for the system performance, but the Profinet IRT was more deterministic.

The impact that mosquitoes and vector-borne diseases have on humans is vast and continues to grow with our expanding global interactions, such as international travel and shipping, so the need for effective vector controls is imperative. Aedes aegypti is a species of mosquito that spreads some of the most common vector-borne diseases, including zika virus, dengue fever, chikungunya, and yellow fever. A. aegypti have yet to be successfully contained, so they are favorable targets for implementing these new vector-control techniques. A review of scientific literature was performed from 1965 to present, timeline was constructed of studies on A. aegypti and their diseases, with inclusion criteria of techniques like bacterial controls and genome editing. Bacterial controls, such as using an endosymbiont like Wolbachia, can result in sterilization of mosquitoes as well as inhibiting the ability for mosquitoes to be infected by pathogens. Genome editing techniques involve CRISPR and gene drives, allowing the manipulation of certain genes to decrease fitness or susceptibility of pathogens. Combining newly discovered genes that play a role in sterilization with the introduction of sterilizing Wolbachia bacteria could result in a more effective method for controlling A. aegypti. Neither technique is known to be entirely effective on its own, but research indicates that highly effective vector-controls could be developed by combining aspects from both fields.

Abstract POLAR FIELD-ORIENTED CONTROL with 3RD HARMONIC INJECTION Martin Todd Hess Field Oriented Control (FOC), also known as vector control, is a widely used and well documented method for controlling Permanent-Magnet Synchronous Motors (PMSM) and induction motors. Almost invariably the orientation of the stator and rotor (field) fluxes are described in rectangular coordinates. In this thesis we explore the practicality of using polar coordinates. Third harmonic injection is also a well-known technique that allows full utilization of the bus (DC-link), thus allowing the motor to run to full base speed without the use of field weakening. This technique potentially allows a 15.4% improvement in the available bus. It has fallen out of use since it requires direct knowledge of the terminal voltage vector angle. The use of polar FOC permits the use of third-harmonic injection. We believe the combination of FOC and third-harmonic injection to be unique, and we present this paper as a novel contribution to the literature on the subject of motor control.

Bakgrund: Samhället behöver ledare inom många olika områden för att utvecklas och förändras. Dessa personer har visat sig ha gemensamma beteenden så som att sätta tydliga mål, finna ett inre syfte och ha passion i det som de gör. Då alla handlingar som utförs av en människa drivs av ett motiv är det intressant att studera vad som motiverar dessa personer. Denna studie har avgränsats till att studera verkställande direktörer. Syfte: Syftet med denna studie är att förstå hur svenska verkställande direktörer beskriver sin motivation utifrån sitt eget perspektiv och således bidra till ökad förståelse för vad som motiverar dessa. Genomförande: Studien är en kvalitativ flerfallstudie med en induktiv forskningsansats. Det empiriska materialet i denna studie är insamlad genom semistrukturerade intervjuer med fyra stycken verkställande direktörer i Sverige. Resultat: Resultatet av denna studie visar att de faktorer som motiverar de verkställande direktörerna, utifrån deras eget perspektiv, varierar. Studien visar tydligt att de verkställande direktörerna främst motiveras av någonting “extra” i deras arbete. Samtliga verkställande direktörer nämnde var för sig att de motiveras starkt av deras respektive företag, utveckling och förändring. / Background: The society need leaders in many different areas to be able to develop and change. These individuals have some common behaviour, such as setting clear goals, finding an inner purpose and having passion for what they do. Since all action by a human being are driven by a motive, it is interesting to study what motivates these people. This essay has been limited to study CEOs. Purpose: The purpose of this study is to understand how Swedish CEOs describe their motivation from their own perspective and contribute to increased understanding of what motivates them. Design: This study is a qualitative multi-case study with an inductive research approach. The empirical material in this study is collected through semi-structured interviews with four different executive directors in Sweden. Conclusion: The result of this study shows that the motivating factors varies between the CEOs. The CEOs are mainly motivated by something “extra” in their work. All of the CEOs separately mentioned that they are strongly motivated by their companies, by development and by change.

With the increased attention on high efficiency and controllability of industrial processes, as well as reduced weight, volume and cost of consumer products, the applications of nonlinear power electronic converters such as adjustable speed drives (ASDs) are showing a rapid rise. Power Quality (PQ) is becoming an increasing concern with the growth of both sensitive and disturbing nonlinear loads in the residential, commercial and industrial levels of the power system, where PQ related disruptions can cause system malfunction, product loss, and hardware damage resulting in costly data loss and downtime. Investigating and mitigating PQ issues pertaining to the input supply of ASDs and other sensitive power electronic equipment is extremely important in maintaining a high level of productivity. In response to these concerns, this research focuses on the development of a power quality test platform (PQTP) that has been implemented at Oregon State University (OSU), in the Motor Systems Resource Facility (MSRF). The central component of the PQTP is a 120kVA programmable ac power source with an integrated arbitrary waveform generator (AWG) which creates realistic voltage disturbance conditions that can be used to characterize ride-through capabilities of industrial processes in a controlled environment. Also presented is a command driver database that has been created and tested, using Lab VIEW, which contains the functionality necessary to conduct a wide range of power quality research and testing projects by remotely configuring and controlling the AWG. The power quality research and testing capabilities of the PQTP are demonstrated with ASD diode-bridge rectifier operation analysis and ride-through characterization. This research shows the transition of an ASD's three-phase diode rectifier into single-phase diode rectifier operation when relatively small single-phase voltage sags are applied to the input. Also shown are ride-through characterizations of varying sizes and configurations of ASDs when subjected to single, two, and three-phase voltage sags as well as capacitor switching transients. In addition, ASD topologies providing improved ride-through capabilities are determined. / Graduation date: 2002

The airflow field and particle trajectories inside hard disk drive (HDD) are investigated in this study using commercial software Fluent and Gambit. Three-dimensional grids inside the HDD configuration are built using Gambit taking into account all the components and their geometric details. The airflow field inside HDD is simulated using three incompressible Navier-Stokes equations for various disk rotational speeds. The effects of using the various turbulence models inside the Fluent software such as the standard k - ε , RNG k - ε and Reynolds Stress Method on the computed airflow characteristics are also assessed. Steady flow fields and the effects of rotational speeds are assessed. Based on the computed steady airflow patterns, particle trajectories are computed using routines available in Fluent as well as special particle trajectory functions defined by the user via the user-defined functions. Particles of different sizes and materials are injected at various locations in the computed flow field and the corresponding particle trajectories are studied. Based on the investigation, the trajectory tends to be different according to sizes and materials. The present work forms a basis for further investigation of heat transfer processes inside the HDD to address thermal management issues and also the computation of unsteady flow fields in the HDD due to the movement of the actuator arm during data storage and retrieval / Singapore-MIT Alliance (SMA)