4 resultados para transistor elettrochimici organici, OECTs, PEDOT:PSS, sensori

em Universidade Federal do Rio Grande do Norte(UFRN)


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The study of Brazilian sedimentary basins concentrates on their rift phase, whereas the Post-rift phase has been considered a tectonic quiescent period. The post-rift sequence of the Potiguar Basin, in the far northeastern Brazil, was once considered little deformed, however several studies have shown how that it was affected by major fault systems. The purpose of this thesis is to characterize the post-rift tectonic. The specific objectives are: to characterize the Neogene and Quaternary sedimentary units that outcrop of the Potiguar Basin; to show how the NW-SEtrending Afonso Bezerra Faults System deformed outcrop rocks in the Basin; to describe soft-sediment deformation in gravels of the Quaternary Alluvial Deposits from Açu River. Facies analyses, grain-size studies, luminescence dating, remote sensing, structural mapping, shallow geophysics (georadar), paleostress and petrography were carried out. The structural mapping and the georadar sections indicated that the Carnaubais and Afonso Bezerra fault systems formed fractures, silicified and non-silicified faults or deformation bands, affecting mainly the Açu, Jandaíra and Barreiras formations. The petrographic data indicate that the strong silicification resulted in a sealant character of the faults. Paleostress analysis indicates that two stress fields affected the Basin: the first presented N-S-trending compression, occurred from the Neocretaceous to the Miocene; the second stress field presents E-W-trending compression, acts from the Miocene to the present. It was verified once the Afonso Bezerra System Faults was reactivated in periods post-Campanian and affects all post-rift lithostratigraphic units of Potiguar Basin, including Quaternary sedimentary covers. The study about soft-sediment deformation structures indicates that they are similar in morphology and size to modern examples of seismically-induced deformation strutures in coarse sediments. TL and OSL ages indicate that sediment deposition and associated soft-sediment deformation occurred at least six times from ~352 Ka to ~9 Ka. Finally these studies demonstrate how recent is tectonics in the Basin Potiguar

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This work deals with the development of an experimental study on a power supply of high frequency that provides the toch plasmica to be implemented in PLASPETRO project, which consists of two static converters developed by using Insulated Gate Bipolar Transistor (IGBT). The drivers used to control these keys are triggered by Digital Signal Processor (DSP) through optical fibers to reduce problems with electromagnetic interference (EMI). The first stage consists of a pre-regulator in the form of an AC to DC converter with three-phase boost power factor correction which is the main theme of this work, while the second is the source of high frequency itself. A series-resonant inverter consists of four (4) cell inverters operating in a frequency around 115 kHz each one in soft switching mode, alternating itself to supply the load (plasma torch) an alternating current with a frequency of 450 kHz. The first stage has the function of providing the series-resonant inverter a DC voltage, with the value controlled from the power supply provided by the electrical system of the utility, and correct the power factor of the system as a whole. This level of DC bus voltage at the output of the first stage will be used to control the power transferred by the inverter to the load, and it may vary from 550 VDC to a maximum of 800 VDC. To control the voltage level of DC bus driver used a proportional integral (PI) controller and to achieve the unity power factor it was used two other proportional integral currents controllers. Computational simulations were performed to assist in sizing and forecasting performance. All the control and communications needed to stage supervisory were implemented on a DSP

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O envelhecimento é um processo multifatorial, influenciado por mudanças biológicas, sociais e psicológicas que pode estar associado ao desenvolvimento de estresse e ao comprometimento da qualidade de vida. O objetivo deste trabalho foi investigar a relação entre o estresse percebido e a qualidade de vida em idosos no município de Campina Grande, PB. O estudo teve um delineamento transversal e descritivo, com abordagem quantitativa, amostragem do tipo snowboll e não probabilística, com amostra composta por 326 idosos, considerando as perdas, totalizaram 253 idosas para a análise dos dados. Foram realizados análises descritivas e testes paramétricos e não-paramétricos entre as características da amostra, adotando um nível de significância de 5%. Utilizou-se como instrumentos um questionário sócio-demográfico e epidemiológico, o Índice de Barthel, a Escala de Atividades Instrumentais de Vida Diária de Lawton e Brody, as Escalas de Estresse Percebido, PSS14 e PSS10 e o SF-36, para avaliar a qualidade de vida relacionada à saúde. As idosas participantes apresentaram o seguinte perfil sócio-demográfico e epidemiológico: idade média de 71,3 anos; 80,2% casadas ou viúvas; 55,3% praticam alguma atividade física; aproximadamente 50% tinham menos de 8 anos de estudo; 76,7% recebiam até dois salários mínimos por mês; a maioria, 82,2%, vivia com a família; e 87,4% apresentava alguma doença crônica. Com relação ao estresse percebido, foi possível identificar que as pontuações da P SS-14 e PSS-10 variaram entre, 2-53 e 4-39, respectivamente, sendo que a quantidade de participantes com valores PSS-14  28 e PSS-10  21 foram de 15.8% (n = 40) e 20.6% (n= 52), respectivamente. Na avaliação da qualidade de vida relacionada à saúde, os escores do SF-36 foram menores nas dimensões de dor (62,7) e aspectos físicos (63,6), e maiores nas dimensões aspectos sociais (84,4) e saúde mental (75,6). Observou-se uma correlação negativa e estatisticamente significativa entre os valores de estresse percebido e os domínios do SF-36 (p <0,001). O estresse percebido relacionou-se tanto com os aspectos físicos e funcionais como com a saúde mental das idosas, apresentando uma associação com a qualidade de vida de forma global, sendo um ótimo indicador da qualidade de vida das idosas.

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The continuous evolution of integrated circuit technology has allowed integrating thousands of transistors on a single chip. This is due to the miniaturization process, which reduces the diameter of wires and transistors. One drawback of this process is that the circuit becomes more fragile and susceptible to break, making the circuit more susceptible to permanent faults during the manufacturing process as well as during their lifetime. Coarse Grained Reconfigurable Architectures (CGRAs) have been used as an alternative to traditional architectures in an attempt to tolerate such faults due to its intrinsic hardware redundancy and high performance. This work proposes a fault tolerance mechanism in a CGRA in order to increase the architecture fault tolerance even considering a high fault rate. The proposed mechanism was added to the scheduler, which is the mechanism responsible for mapping instructions onto the architecture. The instruction mapping occurs at runtime, translating binary code without the need for recompilation. Furthermore, to allow faster implementation, instruction mapping is performed using a greedy module scheduling algorithm, which consists of a software pipeline technique for loop acceleration. The results show that, even with the proposed mechanism, the time for mapping instructions is still in order of microseconds. This result allows that instruction mapping process remains at runtime. In addition, a study was also carried out mapping scheduler rate. The results demonstrate that even at fault rates over 50% in functional units and interconnection components, the scheduler was able to map instructions onto the architecture in most of the tested applications.