O PAPEL MODERADOR DE POTÊNCIA DE EQUIPES SOBRE AS RELAÇÕES ENTRE PERCEPÇÃO DE SUPORTE SOCIAL E BEM-ESTAR SUBJETIVO

Este estudo teve como objetivo investigar o papel moderador de potência de equipes sobre as relações entre percepção de suporte social e bem-estar subjetivo, mediante delineamento longitudinal. A potência de equipes refere-se à crença dos membros na eficácia de sua equipe, enquanto o suporte social é à crença do indivíduo em receber apoio de sua rede social. Já o bem-estar subjetivo demonstra o quanto uma pessoa está satisfeita com sua própria vida. Participaram da pesquisa 249 adolescentes, provenientes de 53 equipes, cada uma composta por três a sete membros, idade média 13,85 anos (DP = 1,86), 57,4% do sexo masculino. O estudo foi realizado em grupos de escoteiros com sedes localizadas em Contagem e Belo Horizonte, Minas Gerais. O instrumento utilizado foi um questionário de autopreenchimento, composto por três escalas que aferiram as três variáveis deste estudo. Os resultados demonstraram que a percepção de suporte social e a potência de equipes influenciaram positiva e significativamente o bem-estar subjetivo dos adolescentes, porém, potência de equipes não foi capaz de moderar a relação entre percepção de suporte social e bem-estar subjetivo. Os adolescentes também mantiveram seus níveis de percepção de suporte social e de crença na potência de equipes em patamares semelhantes. Logo, os adolescentes desfrutavam de bem-estar e saúde psíquica, condição que se manteve ao longo do tempo. Tais evidências asseguram o papel promotor de bem-estar subjetivo tanto de percepção de suporte social quanto de potência de equipes na saúde mental do indivíduo.

Sistema de conversão de energia eólica baseado no gerador de indução duplamente alimentado: análise e contribuição ao controle da máquina

The humanity reached a time of unprecedented technological development. Science has achieved and continues to achieve technologies that allowed increasingly to understand the universe and the laws which govern it, and also try to coexist without destroying the planet we live on. One of the main challenges of the XXI century is to seek and increase new sources of clean energy, renewable and able to sustain our growth and lifestyle. It is the duty of every researcher engage and contribute in this race of energy. In this context, wind power presents itself as one of the great promises for the future of electricity generation . Despite being a bit older than other sources of renewable energy, wind power still presents a wide field for improvement. The development of new techniques for control of the generator along with the development of research laboratories specializing in wind generation are one of the key points to improve the performance, efficiency and reliability of the system. Appropriate control of back-to-back converter scheme allows wind turbines based on the doubly-fed induction generator to operate in the variable-speed mode, whose benefits include maximum power extraction, reactive power injection and mechanical stress reduction. The generator-side converter provides control of active and reactive power injected into the grid, whereas the grid-side converter provides control of the DC link voltage and bi-directional power flow. The conventional control structure uses PI controllers with feed-forward compensation of cross-coupling dq terms. This control technique is sensitive to model uncertainties and the compensation of dynamic dq terms results on a competing control strategy. Therefore, to overcome these problems, it is proposed in this thesis a robust internal model based state-feedback control structure in order to eliminate the cross-coupling terms and thereby improve the generator drive as well as its dynamic behavior during sudden changes in wind speed. It is compared the conventional control approach with the proposed control technique for DFIG wind turbine control under both steady and gust wind conditions. Moreover, it is also proposed in this thesis an wind turbine emulator, which was developed to recreate in laboratory a realistic condition and to submit the generator to several wind speed conditions.

Proteção diferencial de transformadores de potência utilizando a transformada Wavelet

About 10% of faults involving the electrical system occurs in power transformers. Therefore, the protection applied to the power transformers is essential to ensure the continuous operation of this device and the efficiency of the electrical system. Among the protection functions applied to power transformers, the differential protection appears as one of the main schemes, presenting reliable discrimination between internal faults and external faults or inrush currents. However, when using the low frequency components of the differential currents flowing through the transformer, the main difficulty of the conventional methods of differential protection is the delay for detection of the events. However, internal faults, external faults and other disturbances related to the transformer operation present transient and can be appropriately detected by the wavelet transform. In this paper is proposed the development of a wavelet-based differential protection for detection and identification of external faults to the transformer, internal faults, and transformer energizing by using the wavelet coefficient energy of the differential currents. The obtained results reveal the advantages of using of the wavelet transform in the differential protection compared to conventional protection, since it provides reliability and speed in detection of these events.

Estimação de potência em tempo real utilizando a transformada wavelet

The goal of the power monitoring in electrical power systems is to promote the reliablility as well as the quality of electrical power.Therefore, this dissertation proposes a new theory of power based on wavelet transform for real-time estimation of RMS voltages and currents, and some power amounts, such as active power, reactive power, apparent power, and power factor. The appropriate estimation the of RMS and power values is important for many applications, such as: design and analysis of power systems, compensation devices for improving power quality, and instruments for energy measuring. Simulation and experimental results obtained through the proposed MaximalOverlap Discrete Wavelet Transform-based method were compared with the IEEE Standard 1459-2010 and the commercial oscilloscope, respectively, presenting equivalent results. The proposed method presented good performance for compact mother wavelet, which is in accordance with real-time applications.

Topologia de gerador de distúrbios elétricos baseada em conversores de potência

Electrical disturbances such as voltage sags, interruptions and voltage unbalances might cause serious problems for the end-user and for the companies of generation and transmission of energy. Few years ago, those companies have been using methods and equipments of protection to avoid the disturbances’ presence or to mitigate their effects on the power system. Disturbances generators are used to analyse the behavior of electrical and electronic equipments affected by disturbances. The analysis of those failures allows the development of appropriated protection equipments. In this paper, the development of a disturbances generator based on power converters is presented. The disturbance generator developed is able to generate some symmetrical disturbances, such as: voltage sags, voltage swells and harmonic distortion. The control strategy used in the disturbance generator is based on discrete and repetitive control. The steps of the design of the control and of the filter used for reducing harmonic in the output, are detailed in the text. Are presented the obtained results on computational simulations and the obtained results on laboratory tests.

Implementação de conversor de polarização linear-circular para antenas de microfita usando metasuperfícies

This work aims to propose a new model of metasurface with simplified basic cell, able to convert linearly polarized signals generated by planar antenna array in circularly polarized signals, for the ISM frequency band (2.45 GHz), with good bandwidth of return loss and axial ratio. To study the behavior of the proposed structure, the metasurface is coupled to three different structures. First, initial tests are made with the metasurface coupled to a microstrip antenna in its simple configuration. Then the metasurface is coupled to an array with two elements of patch type. And later it is coupled to an optimized array, that uses a stub in its main feed, to get a better impedance matching. The structures are analyzed numerically through Ansoft HFSS™, and to validate these results, the structures are characterized experimentally. The characteristics of transmissions simulated and measures are presented. A good agreement between simulated and measured results was obtained. The structure proposed here has the advantage of meeting the desired characteristics, with a simple geometry to be built using a low-cost substrate (FR-4).

Implementação de conversor de polarização linear-circular para antenas de microfita usando metasuperfícies

This work aims to propose a new model of metasurface with simplified basic cell, able to convert linearly polarized signals generated by planar antenna array in circularly polarized signals, for the ISM frequency band (2.45 GHz), with good bandwidth of return loss and axial ratio. To study the behavior of the proposed structure, the metasurface is coupled to three different structures. First, initial tests are made with the metasurface coupled to a microstrip antenna in its simple configuration. Then the metasurface is coupled to an array with two elements of patch type. And later it is coupled to an optimized array, that uses a stub in its main feed, to get a better impedance matching. The structures are analyzed numerically through Ansoft HFSS™, and to validate these results, the structures are characterized experimentally. The characteristics of transmissions simulated and measures are presented. A good agreement between simulated and measured results was obtained. The structure proposed here has the advantage of meeting the desired characteristics, with a simple geometry to be built using a low-cost substrate (FR-4).

Corpo, força e potência: Nietzsche e Spinoza no pensamento de Deleuze

This dissertation aims at showing the importance of the Nietzsche s and Spinoza s philosophy in Deleuze thought, about body, force, and potency concepts. The search starts from Deleuze texts around two authors of his inspiration, reaching understand in the plan of immanence of the relationship between concepts and the way life as ethics and political affirmation. The first goal is the concept of rhizome; propose by Deleuze in what manner to walk the ways traced by philosophers and at the same time to create self ways. The second chapter examines the body in Nietzsche as force s relations. Find to show the genesis of the force in its determination as relative quantity strong or weak, and as absolute quality active or reactive; and for other side the genesis of the force from two poles of the will to power affirmation or negation, examining the consequences for life and thought. In the third chapter explained the definitions of body in Spinoza. The body, in Spinoza, defines itself complex relation of movement and repose, velocity and slowness and by it s to affect and be affecter s power. Find to show understanding the mediums for to amplify the power of to exist or the potency of to act, in what manner ethics of to live. The fourth chapter makes one parallel between the war and the thought in the constitution of socials body and collectives agenciamientos, for understand in the fifth chapter the body as war s machine of the thought, from the relationship between nomad way life and war s machine showed in Tractate of Nomadologia. Wait like this to show the importance of the ethics and political thought than affirm the existence in the world through active force from that body s power.

Modelagem e análise dinâmica de um sistema de conversão de energia eólica dotado de gerador síncrono de imã permanente utilizando a plataforma ATP

Human development requires a broad balance between ecological, social and economic factors in order to ensure its own sustainability. In this sense, the search for new sources of energy generation, with low deployment and operation costs, which cause the least possible impact to the environment, has been the focus of attention of all society segments. To do so, the reduction in exploration of fossil fuels and the encouragement of using renewable energy resources for distributed generation have proved interesting alternatives to the expansion of the energy matrix of various countries in the world. In this sense, the wind energy has acquired an increasingly significant role, presenting increasing rates of power grid penetration and highlighting technological innovations such as the use of permanent magnet synchronous generators (PMSG). In Brazil, this fact has also been noted and, as a result, the impact of the inclusion of this source in the distribution and sub-transmission power grid has been a major concern of utilities and agents connected to Brazilian electrical sector. Thus, it is relevant the development of appropriate computational tools that allow detailed predictive studies about the dynamic behavior of wind farms, either operating with isolated load, either connected to the main grid, taking also into account the implementation of control strategies for active/reactive power generation and the keeping of adequate levels of voltage and frequency. This work fits in this context since it comprises mathematical and computational developments of a complete wind energy conversion system (WECS) endowed with PMSG using time domain techniques of Alternative Transients Program (ATP), which prides itself a recognized reputation by scientific and academic communities as well as by electricity professionals in Brazil and elsewhere. The modeling procedures performed allowed the elaboration of blocks representing each of the elements of a real WECS, comprising the primary source (the wind), the wind turbine, the PMSG, the frequency converter, the step up transformer, the load composition and the power grid equivalent. Special attention is also given to the implementation of wind turbine control techniques, mainly the pitch control responsible for keeping the generator under the maximum power operation point, and the vector theory that aims at adjusting the active/reactive power flow between the wind turbine and the power grid. Several simulations are performed to investigate the dynamic behavior of the wind farm when subjected to different operating conditions and/or on the occurrence of wind intensity variations. The results have shown the effectiveness of both mathematical and computational modeling developed for the wind turbine and the associated controls.

Caracterización del consumidor en la adopción del comercio electrónico B2C en la ciudad de Manizales – Colombia

En los últimos años, el desarrollo creciente de la tecnología informática ha generado cambios en diferentes aspectos de la vida contemporánea. Las negociaciones, comunicaciones, el entretenimiento, la forma de relacionarse, entre otros aspectos, se han visto afectados por el uso de Internet, obligando a realizar ajustes a las tendencias que vienen transformando al mundo y sus aspectos determinantes.

Sistema electrónico para cuantificar poblaciones de insectos voladores y evaluar atrayentes y repelentes

Esta invención se refiere a un sistema electrónico que permite hacer una evaluación cuantitativa de la cantidad de insectos voladores que intentan atravesar una determina zona del espacio. La zona en donde se realiza el seguimiento de los insectos que intentan atravesarla es una superficie preferentemente plana, donde se ha situado una serie de electrodos conductores, conectados a una fuente de alto voltaje. La finalidad del sistema es proporcionar, un pulso eléctrico cada vez que sea electrocutado un insecto y este pulso eléctrico tiene unas características que permiten que pueda ser aprovechado y procesado por otros sistemas electrónicos, tales como contadores, autómatas programables, microcontroladores, o ser acoplado a los buses de entrada de un ordenador.

Aplicadora autopropulsada de productos fitosanitarios para cultivos hortícolas con control mecánico o electrónico de la dosis

La aplicadora está basada en la utilización de un sistema autopropulsado de tracción mecánica, el cual dispone de un sistema de rodadura de cadenas. Sobre dicho equipo de tracción, se dispondrán de los diversos elementos necesarios para realizar la aplicación de productos fitosanitarios, como por ejemplo un equipo de pulverización, nebulización, etc. El equipo podrá ser utilizado como pulverizador, atomizador, nebulizador y sistema de distribución acoplado a una, instalación fija de productos fitosanitarios de un invernadero, controlando en todas las ocasiones la dosis aplicada sin depender del operario encargado de la aplicación. Este dispositivo presenta una alternativa más eficaz en lo referente a la uniformidad de la distribución, lo que genera una disminución en las dosis aplicadas beneficiando las condiciones de seguridad del operario y el impacto sobre el medio ambiente.

Libro electrónico de superficies y volúmenes para décimo año

En los últimos años ha aumentado el deterioro del medio ambiente causado por la contaminación doméstica e industrial, dañando el aire, el agua y el suelo; afectando la vida de los seres vivos y causando enfermedades. Queremos llegar a los educandos ha que tomen conciencia, se sensibilicen, apliquen alternativas de control de la contaminación y sean multiplicadores de la información, para ello se ha elaborado un material audiovisual, en Power Point con información sencilla, actual, de fácil comprensión sobre los causas y efectos que produce la contaminación producida por el Parque Industrial de Cuenca

Libro electrónico del triángulo para octavos de educación básica

Esta tesis se basa en la presentación de un libro electrónico de geometría para Octavo año de básica, la misma que incorpora conceptos básicos y elementales de la geometría como conceptos básicos de: puntos y líneas; ángulos: clasificación; triángulos: clasificación propiedades, igualdad, semejanza y perímetro; con gráficos de mucho colorido. Contiene sonidos, gifs animados y fotos de alta resolución. En ángulos y triángulos se desarrollan algunas actividades adecuadas, de fácil acceso para los profesores y estudiantes. Se acompaña de una evaluación, la misma que se recomienda aplicar luego de haber revisado la página Web