8 research outputs found

    A Comparison of Power Quality Controllers

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    This paper focuses on certain types of FACTS (Flexibile AC Transmission System) controllers, which can be used for improving the power quality at the point of connection with the power network. It focuses on types of controllers that are suitable for use in large buildings, rather than in transmission networks. The goal is to compare the features of the controllers in specific tasks, and to clarify which solution is best for a specific purpose. It is in some cases better and cheaper to use a combination of controllers than a single controller. The paper also presents the features of a shunt active harmonic compensator, which is a very modern power quality controller that can be used in many cases, or in combination with other controllers. The comparison was made using a matrix diagram that, resulted from mind mapsand other analysis tools. The paper should help engineers to choose the best solution for improving the power quality in a specific power network at distribution level

    A Comparison of Power Quality Controllers

    Get PDF
    This paper focuses on certain types of FACTS (Flexibile AC Transmission System) controllers, which can be used for improving the power quality at the point of connection with the power network. It focuses on types of controllers that are suitable for use in large buildings, rather than in transmission networks. The goal is to compare the features of the controllers in specific tasks, and to clarify which solution is best for a specific purpose. It is in some cases better and cheaper to use a combination of controllers than a single controller. The paper also presents the features of a shunt active harmonic compensator, which is a very modern power quality controller that can be used in many cases, or in combination with other controllers. The comparison was made using a matrix diagram that, resulted from mind mapsand other analysis tools. The paper should help engineers to choose the best solution for improving the power quality in a specific power network at distribution level

    Vliv tvaru křivek svítivosti na rozmístění svítidel

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    The paper discusses a way to deploy a given number of point light sources in the interior to provide required illuminance levels and uniformity of the working plane by using a genetic algorithm. Furthermore a genetic algorithm has been used to generate a proper luminous intensity distribution curve of multiple luminaires to meet the given criteria for the reference plane of the model room for predefined luminaire positions

    A Comparison of Power Quality Controllers

    No full text
    This paper focuses on certain types of FACTS (Flexibile AC Transmission System) controllers, which can be used for improving the power quality at the point of connection with the power network. It focuses on types of controllers that are suitable for use in large buildings, rather than in transmission networks. The goal is to compare the features of the controllers in specific tasks, and to clarify which solution is best for a specific purpose. It is in some cases better and cheaper to use a combination of controllers than a single controller. The paper also presents the features of a shunt active harmonic compensator, which is a very modern power quality controller that can be used in many cases, or in combination with other controllers. The comparison was made using a matrix diagram that, resulted from mind mapsand other analysis tools. The paper should help engineers to choose the best solution for improving the power quality in a specific power network at distribution level

    Atmospheric aging increases the cytotoxicity of bare soot particles in BEAS-2B lung cells

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    Soot particles (SP) are ubiquitous components of atmospheric particulate matter and have been shown to cause various adverse health effects. In the atmosphere, freshly emitted SP can be coated by condensed low-volatility secondary organic and inorganic species. In addition, gas-phase oxidants may react with the surface of SP. Due to the chemical and physical resemblance of SP carbon backbone with polyaromatic hydrocarbon species and their potent oxidation products, we investigated the biological responses of BEAS-2B lung epithelial cells following exposure to fresh- and photochemically aged-SP at the air–liquid interface. A comprehensive physical and chemical aerosol characterization was performed to depict the atmospheric transformations of SP, showing that photochemical aging increased the organic carbon fraction and the oxidation state of the SP. RNA-sequencing and qPCR analysis showed varying gene expression profiles for fresh- and aged-SP. Exposure to aged-SP increased DNA damage, oxidative damage, and upregulation of NRF2-mediated oxidative stress response genes compared to fresh-SP. Furthermore, aged-SP augmented inflammatory cytokine secretion and activated AhR-response, as evidenced by increased expression of AhR-responsive genes. These results indicate that oxidative stress, inflammation, and DNA damage play a key role in the cytotoxicity of SP in BEAS-2B cells, where aging leads to higher toxic responses. Collectively, our results suggest that photochemical aging may increase SP toxicity through surface modifications that lead to an increased toxic response by activating different molecular pathways
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