5 research outputs found

    Advances in Modelling and Control of Wind and Hydrogenerators

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    Rapid deployment of wind and solar energy generation is going to result in a series of new problems with regards to the reliability of our electrical grid in terms of outages, cost, and life-time, forcing us to promptly deal with the challenging restructuring of our energy systems. Increased penetration of fluctuating renewable energy resources is a challenge for the electrical grid. Proposing solutions to deal with this problem also impacts the functionality of large generators. The power electronic generator interactions, multi-domain modelling, and reliable monitoring systems are examples of new challenges in this field. This book presents some new modelling methods and technologies for renewable energy generators including wind, ocean, and hydropower systems

    Modeling, Design and Test of an Integrated Optical Neural Recording Device

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    It has long been a goal of neuroscientists to understand how electrophysiological activity in the nervous system corresponds to, and causes, specific physiological actions. Such knowledge could be used to develop cures for disabilities related to nervous system dysfunction, and to control artificial limbs or restore motion to a paralyzed patient. This has motivated research into technologies, broadly termed brain-machine interfaces, for interfacing with the nervous system. One category of such neural interfaces is implantable neural recording devices, which monitor and record neural signals through a microelectronic device implanted in the body. Typical implantable neural recording devices use a micro-electrode array to record electrical signals simultaneously from a multitude of neurons. Unfortunately, devices employing micro-electrode arrays have several issues from both the biological and circuit design points of view. These issues include tissue damage due to implantation of a micro-electrode array, degradation of recording fidelity over time, limited spatial resolution, the requirement to maintain charge balance in tissue, and the difficulty in implementing low-frequency (large time constant) filter cutoffs with limited chip area. These issues provided the motivation to investigate alternative methods for neural recording - namely optical methods based on fluorescence detection with voltage-sensitive fluorescent proteins. Optical recording methods can alleviate many of the issues with electrical recording, as well as provide other advantages, such as recording targeted to specific neurons/neuron types and higher spatial resolution due to reduced recording site pitch. The major limitations of fully implantable optical recording devices stem from size constraints, the attenuation of light in tissue, which limits imaging depth, and the need for genetically programmed voltage-sensitive fluorescent proteins, which must be introduced to the tissue in the case of chronic recording. This research began with investigating the feasibility of replacing an electrical neural record- ing front end with an optical front end - the conclusion being that producing an initial design was worthwhile. Thus, this thesis presents a prototype optical neural recording device for detecting individual spikes in Layer I of the brain. The device is designed for the fully implantable scenario, where space for typical fluorescence imaging optical components is limited, and a high level of integration is required. The thesis describes: 1) Modeling: a general framework for modeling near-field fluorescence detection systems is presented; the model is then extended and applied to the design of the optical neural recording device for detecting individual spikes in Layer I of the brain, taking into account light attenuation in tissue; 2) Design: the design of a high-sensitivity CMOS imaging chip used in the device; 3) Packaging: the packaging of the CMOS imager with LED dies and an excitation filter; and 4) Testing: the experimental results from testing the packaged device with a fluorescent tissue phantom designed to emulate layer I of the brain. Ideas for future work on such devices are discussed

    Advances in Modelling and Control of Wind and Hydrogenerators

    Get PDF
    Rapid deployment of wind and solar energy generation is going to result in a series of new problems with regards to the reliability of our electrical grid in terms of outages, cost, and life-time, forcing us to promptly deal with the challenging restructuring of our energy systems. Increased penetration of fluctuating renewable energy resources is a challenge for the electrical grid. Proposing solutions to deal with this problem also impacts the functionality of large generators. The power electronic generator interactions, multi-domain modelling, and reliable monitoring systems are examples of new challenges in this field. This book presents some new modelling methods and technologies for renewable energy generators including wind, ocean, and hydropower systems

    De animais a máquinas : humanos tecnicamente melhores nos imaginários de futuro da convergência tecnológica

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    Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Sociais, Departamento de Sociologia, 2020.O tema desta investigação é discutir os imaginários sociais de ciência e tecnologia que emergem a partir da área da neuroengenharia, em sua relação com a Convergência Tecnológica de quatro disciplinas: Nanotecnologia, Biotecnologia, tecnologias da Informação e tecnologias Cognitivas - neurociências- (CT-NBIC). Estas áreas desenvolvem-se e são articuladas por meio de discursos que ressaltam o aprimoramento das capacidades físicas e cognitivas dos seres humanos, com o intuito de construir uma sociedade melhor por meio do progresso científico e tecnológico, nos limites das agendas de pesquisa e desenvolvimento (P&D). Objetivos: Os objetivos nesse cenário, são discutir as implicações éticas, econômicas, políticas e sociais deste modelo de sistema sociotécnico. Nos referimos, tanto as aplicações tecnológicas, quanto as consequências das mesmas na formação dos imaginários sociais, que tipo de relações se estabelecem e como são criadas dentro desse contexto. Conclusão: Concluímos na busca por refletir criticamente sobre as propostas de aprimoramento humano mediado pela tecnologia, que surgem enquanto parte da agenda da Convergência Tecnológica NBIC. No entanto, as propostas de melhoramento humano vão muito além de uma agenda de investigação. Há todo um quadro de referências filosóficas e políticas que defendem o aprimoramento da espécie, vertentes estas que se aliam a movimentos trans-humanistas e pós- humanistas, posições que são ao mesmo tempo éticas, políticas e econômicas. A partir de nossa análise, entendemos que ciência, tecnologia e política estão articuladas, em coprodução, em relação às expectativas de futuros que são esperados ou desejados. Ainda assim, acreditamos que há um espaço de diálogo possível, a partir do qual buscamos abrir propostas para o debate público sobre questões de ciência e tecnologia relacionadas ao aprimoramento da espécie humana.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The subject of this research is to discuss the social imaginaries of science and technology that emerge from the area of neuroengineering in relation with the Technological Convergence of four disciplines: Nanotechnology, Biotechnology, Information technologies and Cognitive technologies -neurosciences- (CT-NBIC). These areas are developed and articulated through discourses that emphasize the enhancement of human physical and cognitive capacities, the intuition it is to build a better society, through the scientific and technological progress, at the limits of the research and development (R&D) agendas. Objectives: The objective in this scenery, is to discuss the ethic, economic, politic and social implications of this model of sociotechnical system. We refer about the technological applications and the consequences of them in the formation of social imaginaries as well as the kind of social relations that are created and established in this context. Conclusion: We conclude looking for critical reflections about the proposals of human enhancement mediated by the technology. That appear as a part of the NBIC technologies agenda. Even so, the proposals of human enhancement go beyond boundaries that an investigation agenda. There is a frame of philosophical and political references that defend the enhancement of the human beings. These currents that ally to the transhumanism and posthumanism movements, positions that are ethic, politic and economic at the same time. From our analysis, we understand that science, technology and politics are articulated, are in co-production, regarding the expected and desired futures. Even so, we believe that there is a space of possible dialog, from which we look to open proposals for the public discussion on questions of science and technology related to enhancement of human beings
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