This paper presents a novel design for a Dyson-Harrop CubeSat aimed at harvesting energy from the solar wind. Unlike current photovoltaic-based satellite energy generation, the Dyson-Harrop satellite generates energy ...This paper presents a novel design for a Dyson-Harrop CubeSat aimed at harvesting energy from the solar wind. Unlike current photovoltaic-based satellite energy generation, the Dyson-Harrop satellite generates energy based on the photoelectric effect, which has the potential to achieve significantly higher efficiency than current photovoltaic technology. The proposed CubeSat system consists of three main components: a tether unit, an energy harvesting unit, and the central 3U CubeSat body. The tether unit generates a cylindrical magnetic field along its main tether,effectively concentrating electrons from the solar wind to the energy harvesting unit. The energy harvesting unit includes a spherical electron receiver, functioning as a capacitor, which attracts electrons from the solar wind, as well as an annular flat solar sail that captures photons in the solar wind to eject electrons via the photoelectric effect, resulting in an electric current in the system.The Dyson-Harrop CubeSat is shown to be highly efficient as an energy-generation system, producing approximately 1 kW of power by a 3U CubeSat. This energy can be transmitted via microwave beams to other spacecraft or ground stations on the Earth. It is important to note that this estimation is based on first-principle estimations, and thorough theoretical analysis and experimental validation are required to confirm the feasibility of the concept.展开更多
Microbial fuel cells(MFcs)provide a promising solution forsustainable power generation and simultaneous wastewatertreatment.One of the central roles in the applicationadvances of MFCs is to propel the innovation of ef...Microbial fuel cells(MFcs)provide a promising solution forsustainable power generation and simultaneous wastewatertreatment.One of the central roles in the applicationadvances of MFCs is to propel the innovation of efficientand renewable oxygen reduction reaction(ORR)bioelectro-catalysts in air-cathode.Herein,a surface co-engineeredliving cell bioelectrocatalyst was demonstrated through thecoupling strategy of genetic engineering and nanomaterialsengineering,aiming at rationally regulating the ORRcatalytic function of the whole-cell and the bioelectricitygeneration capacity:First,Escherichia coli(E.colf)cells weregenetically programmed to display a mass of bilirubin oxi-dase(BoD)on the cell surface,enabling plentiful splendidcatalytic activity sites for ORR.Further,cell surface encapsu-lation with conductive polypyrrole(PPy)nanomaterials wasestablished,contributing to the enhancement of the con-ductivity of the cell membrane and promotion of the elec-tron transfer efficiency of the abiotic-biotic interface.Besides,the PPy materials formed a tight electron transportnetwork around the BOD active sites,achieving a synergistic catalytic effect.The designed co-engineered E.coli cellsexerted superior electrocatalytic ORR performance with amaximum current density of 3.1mA cm^(-2) and onset potentialof o.61 V.Additionally,the maximum power output of MFCSassembled with this living cell air-cathode biocatalystreached 188.7 uW cm^(-2).Our results not only provide a newavenue to regulate fuel cell activity and function for adesirable chemical reaction but also demonstrate the plas-ticity of the cell surface engineering system.展开更多
After the deregulation of the Power Sector in the U.S., planning for generation and transmission capacities is decentralized. There is, however, still need for the long term integrated planning of generation and trans...After the deregulation of the Power Sector in the U.S., planning for generation and transmission capacities is decentralized. There is, however, still need for the long term integrated planning of generation and transmission capacities at the macro level, since these two sectors must operate in a coordinated manner. This paper presents a model for integrating generation and transmission expansion planning to identify an indicative expansion plan for the total sector at the macro level. The argument for an integrated model is supported using evidence from integrated planning efforts in real life systems. The application of the proposed model is illustrated using an example that requires expansion of generation and transmission capacities over three regions in a deregulated power system. The example considers that addition of generating capacity should come from renewable sources. The test results show the potential cost saving from integrated planning.展开更多
The analysis of the wind-driven self-excited induction generators （SEIGs） connected to the grid through power converters has been developed in this paper. For this analysis, a method of representing the grid power a...The analysis of the wind-driven self-excited induction generators （SEIGs） connected to the grid through power converters has been developed in this paper. For this analysis, a method of representing the grid power as equivalent load resistance in the steady-state equivalent circuit of SEIG has been formulated. The technique of genetic algorithm （GA） has been adopted for making the analysis of the proposed system simple and straightfor- ward. The control of SEIG is attempted by connecting an uncontrolled diode bridge rectifier （DBR） and a line commutated inverter （LCI） between the generator term- inals and three-phase utility grid. A simple control technique for maximum power point tracking （MPPT） in wind energy conversion systems （WECS）, in which the firing angle of the LCI alone needs to be controlled by sensing the rotor speed of the generator has been proposed. The effectiveness of the proposed method of MPPT and method of analysis of this wind-driven SEIG-converter system connected to the grid through power converters has been demonstrated by experiments and simulation. These experimental and simulated results confirm the usefulness and successful working of the proposed system and its analysis.展开更多
Separator between anode and cathode is an essential part of the microbial fuel cell （MFC） and its property could significantly influence the system perfor- mance. In this study we used polyvinyl alcohol （PVA） poly...Separator between anode and cathode is an essential part of the microbial fuel cell （MFC） and its property could significantly influence the system perfor- mance. In this study we used polyvinyl alcohol （PVA） polymer membrane crosslinked with sulfosuccinic acid （SSA） as a new separator for the MFC. The highest power density of 7594-4 mW-m-2 was obtained when MFC using the PVA membrane crosslinked with 15% of SSA due to its desirable proton conductivity （5.16 x 10-2 S.cml）. The power density significantly increased to 11064- 30 mW.m-2 with a separator-electrode-assembly config- uration, which was comparable with glass fiber （11704- 46 mW.m-2）. The coulombic efficiencies of the MFCs with crosslinked PVA membranes ranged from 36.3% to 45.7% at a fix external resistance of lO00f2. The crosslinked PVA membrane could be a promising alter- native to separator materials for constructing practical MFC system.展开更多
基金supported by the Discovery grant(No.RGPIN-2024-06290)the CREATE grant(No.504156)of the Natural Sciences and Engineering Research Council of Canada.
文摘This paper presents a novel design for a Dyson-Harrop CubeSat aimed at harvesting energy from the solar wind. Unlike current photovoltaic-based satellite energy generation, the Dyson-Harrop satellite generates energy based on the photoelectric effect, which has the potential to achieve significantly higher efficiency than current photovoltaic technology. The proposed CubeSat system consists of three main components: a tether unit, an energy harvesting unit, and the central 3U CubeSat body. The tether unit generates a cylindrical magnetic field along its main tether,effectively concentrating electrons from the solar wind to the energy harvesting unit. The energy harvesting unit includes a spherical electron receiver, functioning as a capacitor, which attracts electrons from the solar wind, as well as an annular flat solar sail that captures photons in the solar wind to eject electrons via the photoelectric effect, resulting in an electric current in the system.The Dyson-Harrop CubeSat is shown to be highly efficient as an energy-generation system, producing approximately 1 kW of power by a 3U CubeSat. This energy can be transmitted via microwave beams to other spacecraft or ground stations on the Earth. It is important to note that this estimation is based on first-principle estimations, and thorough theoretical analysis and experimental validation are required to confirm the feasibility of the concept.
基金supported by the National ScienceFoundation of China (grant nos.52271176 and 52472200)the 111Project,China(grant no.D17007)+1 种基金Henan Center for OutstandingOverseas Scientists,China(grant no.GzS2022017)the KeySpecialized Research and Development-International scienceand Technology Cooperation Program in Henan Province,China(grant no.231111520500).
文摘Microbial fuel cells(MFcs)provide a promising solution forsustainable power generation and simultaneous wastewatertreatment.One of the central roles in the applicationadvances of MFCs is to propel the innovation of efficientand renewable oxygen reduction reaction(ORR)bioelectro-catalysts in air-cathode.Herein,a surface co-engineeredliving cell bioelectrocatalyst was demonstrated through thecoupling strategy of genetic engineering and nanomaterialsengineering,aiming at rationally regulating the ORRcatalytic function of the whole-cell and the bioelectricitygeneration capacity:First,Escherichia coli(E.colf)cells weregenetically programmed to display a mass of bilirubin oxi-dase(BoD)on the cell surface,enabling plentiful splendidcatalytic activity sites for ORR.Further,cell surface encapsu-lation with conductive polypyrrole(PPy)nanomaterials wasestablished,contributing to the enhancement of the con-ductivity of the cell membrane and promotion of the elec-tron transfer efficiency of the abiotic-biotic interface.Besides,the PPy materials formed a tight electron transportnetwork around the BOD active sites,achieving a synergistic catalytic effect.The designed co-engineered E.coli cellsexerted superior electrocatalytic ORR performance with amaximum current density of 3.1mA cm^(-2) and onset potentialof o.61 V.Additionally,the maximum power output of MFCSassembled with this living cell air-cathode biocatalystreached 188.7 uW cm^(-2).Our results not only provide a newavenue to regulate fuel cell activity and function for adesirable chemical reaction but also demonstrate the plas-ticity of the cell surface engineering system.
文摘After the deregulation of the Power Sector in the U.S., planning for generation and transmission capacities is decentralized. There is, however, still need for the long term integrated planning of generation and transmission capacities at the macro level, since these two sectors must operate in a coordinated manner. This paper presents a model for integrating generation and transmission expansion planning to identify an indicative expansion plan for the total sector at the macro level. The argument for an integrated model is supported using evidence from integrated planning efforts in real life systems. The application of the proposed model is illustrated using an example that requires expansion of generation and transmission capacities over three regions in a deregulated power system. The example considers that addition of generating capacity should come from renewable sources. The test results show the potential cost saving from integrated planning.
文摘The analysis of the wind-driven self-excited induction generators （SEIGs） connected to the grid through power converters has been developed in this paper. For this analysis, a method of representing the grid power as equivalent load resistance in the steady-state equivalent circuit of SEIG has been formulated. The technique of genetic algorithm （GA） has been adopted for making the analysis of the proposed system simple and straightfor- ward. The control of SEIG is attempted by connecting an uncontrolled diode bridge rectifier （DBR） and a line commutated inverter （LCI） between the generator term- inals and three-phase utility grid. A simple control technique for maximum power point tracking （MPPT） in wind energy conversion systems （WECS）, in which the firing angle of the LCI alone needs to be controlled by sensing the rotor speed of the generator has been proposed. The effectiveness of the proposed method of MPPT and method of analysis of this wind-driven SEIG-converter system connected to the grid through power converters has been demonstrated by experiments and simulation. These experimental and simulated results confirm the usefulness and successful working of the proposed system and its analysis.
文摘Separator between anode and cathode is an essential part of the microbial fuel cell （MFC） and its property could significantly influence the system perfor- mance. In this study we used polyvinyl alcohol （PVA） polymer membrane crosslinked with sulfosuccinic acid （SSA） as a new separator for the MFC. The highest power density of 7594-4 mW-m-2 was obtained when MFC using the PVA membrane crosslinked with 15% of SSA due to its desirable proton conductivity （5.16 x 10-2 S.cml）. The power density significantly increased to 11064- 30 mW.m-2 with a separator-electrode-assembly config- uration, which was comparable with glass fiber （11704- 46 mW.m-2）. The coulombic efficiencies of the MFCs with crosslinked PVA membranes ranged from 36.3% to 45.7% at a fix external resistance of lO00f2. The crosslinked PVA membrane could be a promising alter- native to separator materials for constructing practical MFC system.
