The Experts below are selected from a list of 72 Experts worldwide ranked by ideXlab platform
Marcelo Godoy Simoes - One of the best experts on this subject based on the ideXlab platform.
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three port bidirectional converter for hybrid fuel cell systems
IEEE Transactions on Power Electronics, 2007Co-Authors: J L Duarte, M A M Hendrix, Marcelo Godoy SimoesAbstract:The implementation of a hybrid fuel cell/battery system is proposed to improve the slow transient response of a fuel cell stack. This system can be used for an Autonomous Device with quick load variations. A suitable three-port, galvanic isolated, bidirectional power converter is proposed to control the power flow. An energy management method for the proposed three-port circuit is analyzed and implemented. Measurements from a 500-W laboratory prototype are presented to demonstrate the validity of the approach
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a three port bi directional converter for hybrid fuel cell systems
Power Electronics Specialists Conference, 2004Co-Authors: M M J A Michon, J L Duarte, Mam Marcel Hendrix, Marcelo Godoy SimoesAbstract:The implementation of a fuel cell/battery hybrid system is proposed to improve the slow transient response of a PEM fuel cell stack. This system can be used for an Autonomous Device with quick load variations. A suitable three-port, galvanic isolated, bi-directional power converter is proposed to control the power flow. An energy management method for the proposed three-port circuit is analyzed and implemented. Measurements from a 500 W laboratory prototype are presented to demonstrate the validity of the approach.
J L Duarte - One of the best experts on this subject based on the ideXlab platform.
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three port bidirectional converter for hybrid fuel cell systems
IEEE Transactions on Power Electronics, 2007Co-Authors: J L Duarte, M A M Hendrix, Marcelo Godoy SimoesAbstract:The implementation of a hybrid fuel cell/battery system is proposed to improve the slow transient response of a fuel cell stack. This system can be used for an Autonomous Device with quick load variations. A suitable three-port, galvanic isolated, bidirectional power converter is proposed to control the power flow. An energy management method for the proposed three-port circuit is analyzed and implemented. Measurements from a 500-W laboratory prototype are presented to demonstrate the validity of the approach
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a three port bi directional converter for hybrid fuel cell systems
Power Electronics Specialists Conference, 2004Co-Authors: M M J A Michon, J L Duarte, Mam Marcel Hendrix, Marcelo Godoy SimoesAbstract:The implementation of a fuel cell/battery hybrid system is proposed to improve the slow transient response of a PEM fuel cell stack. This system can be used for an Autonomous Device with quick load variations. A suitable three-port, galvanic isolated, bi-directional power converter is proposed to control the power flow. An energy management method for the proposed three-port circuit is analyzed and implemented. Measurements from a 500 W laboratory prototype are presented to demonstrate the validity of the approach.
Ioannis Ieropoulos - One of the best experts on this subject based on the ideXlab platform.
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self powered Autonomous biological oxygen demand biosensor for online water quality monitoring
Sensors and Actuators B-chemical, 2017Co-Authors: Grzegorz Pasternak, John Greenman, Ioannis IeropoulosAbstract:Standard Biological Oxygen Demand (BOD) analysis requires 5 days to complete. To date, microbial fuel cell biosensors used as an alternative method for BOD assessment requires external apparatus, which limits their use for on-line monitoring in remote, off-grid locations. In this study, a self-powered, floating biosensor was developed for online water quality monitoring. This approach eliminated the need for external apparatus and maintenance that would otherwise be required by other techniques. The biosensor was able to detect urine in freshwater and turn ON a visual and sound cues (85 dB). The energy needed to operate the biosensor was produced by the system itself with the use of electroactive microorganisms, inside microbial fuel cells. The Chemical Oxygen Demand (COD) was used as a fast method of biosensor validation. When urine concentration exceeded the lower threshold, corresponding to a COD concentration of 57.7 ± 4.8 mgO2 L−1, the biosensor turned the alarm ON. The shortest observed actuation time, required to switch ON the alarm was 61 min, when the urine concentration was 149.7 ± 1.7 mgO2 L−1. Once the sensor was switched ON, the signal was emitted until the urine organic load decreased to 15.3 ± 1.9 mgO2 L−1. When ON, the microbial fuel cell sensor produced a maximum power of 4.3 mW. When switched OFF, the biosensor produced 25.4 μW. The frequency of the signal was proportional to the concentration of urine. The observed frequencies varied between 0.01 and 0.59 Hz. This approach allowed to correlate and quantitatively detect the presence of water contamination, based on signal frequency. The sensor was operating Autonomously for 5 months. This is the first report of a self-powered, Autonomous Device, developed for online water quality monitoring.
Geza Toth - One of the best experts on this subject based on the ideXlab platform.
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on chip integrated vertically aligned carbon nanotube based super and pseudocapacitors
Scientific Reports, 2017Co-Authors: Olli Pitkanen, Topias Jarvinen, Hansong Cheng, Gabriela S Lorite, Aron Dombovari, Lassi Rieppo, Saikat Talapatra, Hai M Duong, Geza TothAbstract:On-chip energy storage and management will have transformative impacts in developing advanced electronic platforms with built-in energy needs for operation of integrated circuits driving a microprocessor. Though success in growing stand-alone energy storage elements such as electrochemical capacitors (super and pseusocapacitors) on a variety of substrates is a promising step towards this direction. In this work, on-chip energy storage is demonstrated using architectures of highly aligned vertical carbon nanotubes (CNTs) acting as supercapacitors, capable of providing large Device capacitances. The efficiency of these structures is further increased by incorporating electrochemically active nanoparticles such as MnOx to form pseudocapacitive architectures thus enhancing Device capacitance areal specific capacitance of 37 mF/cm2. The demonstrated on-chip integration is up and down-scalable, compatible with standard CMOS processes, and offers lightweight energy storage what is vital for portable and Autonomous Device operation with numerous advantages as compared to electronics built from discrete components.
Donald Lupo - One of the best experts on this subject based on the ideXlab platform.
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behaviour of one step spray coated carbon nanotube supercapacitor in ambient light harvester circuit with printed organic solar cell and electrochromic display
Scientific Reports, 2016Co-Authors: Sampo Tuukkanen, Suvi Lehtimaki, Tiina Vuorinen, Marja Välimäki, Donald LupoAbstract:A printed energy harvesting and storage circuit powered by ambient office lighting and its use to power a printed display is reported. The Autonomous Device is composed of three printed electronic components: an organic photovoltaic module, a carbon-nanotubes-only supercapacitor and an electrochromic display element. Components are fabricated from safe and environmentally friendly materials, and have been fabricated using solution processing methods, which translate into low-cost and high-throughput manufacturing. A supercapacitor made of spray-coated carbon nanotube based ink and aqueous NaCl electrolyte was charged using a printed organic photovoltaic module exposed to office lighting conditions. The supercapacitor charging rate, self-discharge rate and display operation were studied in detail. The supercapacitor self-discharge rate was found to depend on the charging rate. The fully charged supercapacitor was used as a power source to run the electrochromic display over 50 times.
