In Japan, residential FCs （fuel cells） are being introduced not only in detached houses but also in collective housing. In this context, the effects of FC introduction （e.g., primary energy savings） should be quan...In Japan, residential FCs （fuel cells） are being introduced not only in detached houses but also in collective housing. In this context, the effects of FC introduction （e.g., primary energy savings） should be quantitatively evaluated, but this has not been done sufficiently for collective housing, particularly with regard to demand variability. Here, the authors propose a method taking into account demand variability to evaluate the effects of FC introduction into collective housing, based on a finite set of observational demand data. The method provides a new viewpoint for evaluating the effects of FC introduction. Numerical simulation results based on real-world data indicate the validity of these effects in terms of primary energy savings and CO2 reduction considering demand variability.展开更多
This paper describes the fabrication of a waveguide and the analysis of its polarization characteristics by applying light-emitting diode(LED) pumping lights to its surface.By using double tubed coaxial line(DTCL) mic...This paper describes the fabrication of a waveguide and the analysis of its polarization characteristics by applying light-emitting diode(LED) pumping lights to its surface.By using double tubed coaxial line(DTCL) microwave plasma chemical vapor deposition(MPCVD) equipment,an a-Si:H/SiN multilayer waveguide was fabricated whose thickness could be controlled at nanometer order.The main structural material of the waveguide sample consisted of a combination of layers of amorphous silicon hydrogen and silicon nitrate.Once the sample was ready,another major objective of the experiment was to analyze the polarization characteristics of the fabricated waveguide.The idea of the experiment was to analyze how the waveguide reacts when three types of LED(blue,yellow,and red) are radiated onto its surface.The results showed that the fabrication of the a-Si:H/SiN sample is successful.Most effective transmission results,which accord with the polarization characteristics analysis,were obtained.展开更多
Detection of polystyrene beads with a diameter of 100 nm was conducted using an optical disk drive tester equipped with a laser of 405 nm wavelength and an objective lens with a numerical aperture of 0.65. The polysty...Detection of polystyrene beads with a diameter of 100 nm was conducted using an optical disk drive tester equipped with a laser of 405 nm wavelength and an objective lens with a numerical aperture of 0.65. The polystyrene beads were used to mimic the influenza virus. A grooved disk with a (ZnS)85(SiO2)15/SiO2 layered surface structure was used for the detection. The detection of influenza viruses (A/Udorn/307/1972) with Au nanoparticles was also demonstrated using the optical disk drive tester. In this case, a grooved disk with an indium tin oxide (ITO) film was used. The ITO film functioned both to tune the reflectance of the disk and as an electrically conductive layer for scanning electron microscopy. In both cases, the target substances were successfully recognized in a single scan with a high scanning speed of 4.9 m/s. The results indicate that this optical disk system can be used to detect 100 nm scale substances like influenza viruses, which are smaller than the diffraction limit of the system.展开更多
There is a danger of power generation efficiency decreasing due to voltage increase when clustered residential PV systems are grid-interconnected to a single distribution line. As a countermeasure, installation of the...There is a danger of power generation efficiency decreasing due to voltage increase when clustered residential PV systems are grid-interconnected to a single distribution line. As a countermeasure, installation of the reactive power control of an inverter at each residence has been considered. However, there are not many types of inverters that can operate reactive power control because there are insufficient effects on a low voltage distribution line with low penetration PV with reactive power control. Therefore, it is necessary to consider how to increase generation efficiency with a lower number of inverters. In this paper, four Japanese standard distribution line structures, for example of a residential area on ＂C1＂, where 2,160 residential PV systems are grid-interconnected, are selected. The optimal setting of reactive power control at each residence is computed on the distribution lines with a greedy method.展开更多
Cable-grade silicone rubber was aged thermally or by combining heat and gamma-ray radiation,and resultant changes in chemical,thermal,mechanical and electrical properties were examined.The experimental results obtaine...Cable-grade silicone rubber was aged thermally or by combining heat and gamma-ray radiation,and resultant changes in chemical,thermal,mechanical and electrical properties were examined.The experimental results obtained in these analyses are clearly consistent with the mechanism that silicone rubber is degraded by forming cross-linked structures via formation of abundant siloxane bonds.With further progress of degradation,decomposition becomes dominant.Reflecting these mechanisms,mechanical properties deteriorate dramatically by losing elasticity.Both the real and imaginary parts of complex permittivity decrease,which is a contrastive difference from typical ageing behaviour of organic insulating polymers.In addition,both the elongation at break and indenter modulus are good indicators of degradation of silicone rubber.展开更多
Antioxidants are usually added to polymeric insulating materials to suppress oxidative degradation.However,the details of antioxidant added to a polymer are often not disclosed.On the other hand,compared to mid-infrar...Antioxidants are usually added to polymeric insulating materials to suppress oxidative degradation.However,the details of antioxidant added to a polymer are often not disclosed.On the other hand,compared to mid-infrared absorption spectroscopy,terahertz(THz)absorption spectroscopy,and far-infrared(FIR)absorption spectroscopy have not been performed so often.Based on the above backgrounds,six different kinds of antioxidants were added into low-density polyethylene sheets with four different contents,and their THz and FIR absorption spectra were measured.As a result,it has become clear that each antioxidant shows its specific absorption peaks,by which the antioxidants can be identified.Furthermore,the antioxidant content can be estimated by the absorption intensity of the specific peak.A chemometric analysis can make the estimation more accurately than a simple comparison of absorption intensity.展开更多
Reactive power control can control voltage within the proper range from the power network side or from the distribution generation （PV （photovoltaic）） side. Reactive power control from the power network side is si...Reactive power control can control voltage within the proper range from the power network side or from the distribution generation （PV （photovoltaic）） side. Reactive power control from the power network side is simpler because little controlled object apparatus, such as STATCOM, is required. However, it is difficult to optimize the individual voltages of residential consumers because few data have been obtained by the power network side as compared with the power generation side. Energy loss at each residence with PV is different due to the difference in the grid-interconnection condition, such as distribution line impedance when the same operating voltage is set at all residences. Therefore, in this paper, the authors propose an advanced reactive power control method for residential PV systems in order to optimally control the voltage at individual residences so as to minimize energy loss fluctuation. The effectiveness of the proposed reactive power control is demonstrated by numerical simulation.展开更多
CONSPECTUS:Sustainable development cannot be achieved without substantial technological advancements.For instance,flexible electricity management requires smart power sourcing with advanced energy storage/conversion t...CONSPECTUS:Sustainable development cannot be achieved without substantial technological advancements.For instance,flexible electricity management requires smart power sourcing with advanced energy storage/conversion technologies.Remedies for abrupt power spikes/drops observed in renewable energy sources such as solar and wind require rapid load-leveling using high-power energy storage systems when they are integrated into a microgrid.Electrochemical energy storage devices efficiently convert electrical and chemical energy,which can potentially function as distributed power sources.Among these,lithium-ion batteries are a present de facto standard with their relatively high energy density and energy efficiencies that are based on topochemical intercalation chemistry,whereby vip lithium ions are(de)intercalated reversibly with simultaneous redox reactions and minimal structural changes.However,their energy density,power density,life-cycle cost,calendar life,and safety remain unsatisfactory for widespread use.When the storage capacity is maximized,as a result of which a labile deep charge/discharge state is generated,to develop batteries with high energy density,subsequent irreversible phase transformations or chemical reactions occur in many cases.The combination of the reversible electrode reactions and the subsequent irreversible phase transformations sometimes causes a charge/discharge curve characterized by a large voltage hysteresis with 100%Coulombic efficiency.Because a large voltage hysteresis significantly degrades the energy efficiency,unveiling the reaction mechanism is of primary importance in mitigating energy loss.展开更多
文摘In Japan, residential FCs （fuel cells） are being introduced not only in detached houses but also in collective housing. In this context, the effects of FC introduction （e.g., primary energy savings） should be quantitatively evaluated, but this has not been done sufficiently for collective housing, particularly with regard to demand variability. Here, the authors propose a method taking into account demand variability to evaluate the effects of FC introduction into collective housing, based on a finite set of observational demand data. The method provides a new viewpoint for evaluating the effects of FC introduction. Numerical simulation results based on real-world data indicate the validity of these effects in terms of primary energy savings and CO2 reduction considering demand variability.
基金supported by the Waseda University Undergraduate Fund,Japan, and Malaysia Majlis Amanah Rakyat (MARA) through the MARA Scholarship Foundation
文摘This paper describes the fabrication of a waveguide and the analysis of its polarization characteristics by applying light-emitting diode(LED) pumping lights to its surface.By using double tubed coaxial line(DTCL) microwave plasma chemical vapor deposition(MPCVD) equipment,an a-Si:H/SiN multilayer waveguide was fabricated whose thickness could be controlled at nanometer order.The main structural material of the waveguide sample consisted of a combination of layers of amorphous silicon hydrogen and silicon nitrate.Once the sample was ready,another major objective of the experiment was to analyze the polarization characteristics of the fabricated waveguide.The idea of the experiment was to analyze how the waveguide reacts when three types of LED(blue,yellow,and red) are radiated onto its surface.The results showed that the fabrication of the a-Si:H/SiN sample is successful.Most effective transmission results,which accord with the polarization characteristics analysis,were obtained.
文摘Detection of polystyrene beads with a diameter of 100 nm was conducted using an optical disk drive tester equipped with a laser of 405 nm wavelength and an objective lens with a numerical aperture of 0.65. The polystyrene beads were used to mimic the influenza virus. A grooved disk with a (ZnS)85(SiO2)15/SiO2 layered surface structure was used for the detection. The detection of influenza viruses (A/Udorn/307/1972) with Au nanoparticles was also demonstrated using the optical disk drive tester. In this case, a grooved disk with an indium tin oxide (ITO) film was used. The ITO film functioned both to tune the reflectance of the disk and as an electrically conductive layer for scanning electron microscopy. In both cases, the target substances were successfully recognized in a single scan with a high scanning speed of 4.9 m/s. The results indicate that this optical disk system can be used to detect 100 nm scale substances like influenza viruses, which are smaller than the diffraction limit of the system.
文摘There is a danger of power generation efficiency decreasing due to voltage increase when clustered residential PV systems are grid-interconnected to a single distribution line. As a countermeasure, installation of the reactive power control of an inverter at each residence has been considered. However, there are not many types of inverters that can operate reactive power control because there are insufficient effects on a low voltage distribution line with low penetration PV with reactive power control. Therefore, it is necessary to consider how to increase generation efficiency with a lower number of inverters. In this paper, four Japanese standard distribution line structures, for example of a residential area on ＂C1＂, where 2,160 residential PV systems are grid-interconnected, are selected. The optimal setting of reactive power control at each residence is computed on the distribution lines with a greedy method.
基金supported by the Nuclear Regulation Authority in Japan through Ageing Management Technical Evaluation Enhancement Program.
文摘Cable-grade silicone rubber was aged thermally or by combining heat and gamma-ray radiation,and resultant changes in chemical,thermal,mechanical and electrical properties were examined.The experimental results obtained in these analyses are clearly consistent with the mechanism that silicone rubber is degraded by forming cross-linked structures via formation of abundant siloxane bonds.With further progress of degradation,decomposition becomes dominant.Reflecting these mechanisms,mechanical properties deteriorate dramatically by losing elasticity.Both the real and imaginary parts of complex permittivity decrease,which is a contrastive difference from typical ageing behaviour of organic insulating polymers.In addition,both the elongation at break and indenter modulus are good indicators of degradation of silicone rubber.
基金This research was performed under the research entrusted by Secretariat of Nuclear Regulation Authority.
文摘Antioxidants are usually added to polymeric insulating materials to suppress oxidative degradation.However,the details of antioxidant added to a polymer are often not disclosed.On the other hand,compared to mid-infrared absorption spectroscopy,terahertz(THz)absorption spectroscopy,and far-infrared(FIR)absorption spectroscopy have not been performed so often.Based on the above backgrounds,six different kinds of antioxidants were added into low-density polyethylene sheets with four different contents,and their THz and FIR absorption spectra were measured.As a result,it has become clear that each antioxidant shows its specific absorption peaks,by which the antioxidants can be identified.Furthermore,the antioxidant content can be estimated by the absorption intensity of the specific peak.A chemometric analysis can make the estimation more accurately than a simple comparison of absorption intensity.
文摘Reactive power control can control voltage within the proper range from the power network side or from the distribution generation （PV （photovoltaic）） side. Reactive power control from the power network side is simpler because little controlled object apparatus, such as STATCOM, is required. However, it is difficult to optimize the individual voltages of residential consumers because few data have been obtained by the power network side as compared with the power generation side. Energy loss at each residence with PV is different due to the difference in the grid-interconnection condition, such as distribution line impedance when the same operating voltage is set at all residences. Therefore, in this paper, the authors propose an advanced reactive power control method for residential PV systems in order to optimally control the voltage at individual residences so as to minimize energy loss fluctuation. The effectiveness of the proposed reactive power control is demonstrated by numerical simulation.
基金This work was financially supported by a Ministry of Education,Culture,Sports,Science and Technology(MEXT),Japan,Grant-in-Aid for Scientific Research(S)(no.20H05673)This work was also supported by the“Elements Strategy Initiative for Catalysts and Batteries(ESICB)”.M.O.was financially supported by the Japan Society for the Promotion of Science(JPSP)KAKENHI(grant nos.19H05816,18K19124,and 21H04697)the Asahi Glass Foundation.
文摘CONSPECTUS:Sustainable development cannot be achieved without substantial technological advancements.For instance,flexible electricity management requires smart power sourcing with advanced energy storage/conversion technologies.Remedies for abrupt power spikes/drops observed in renewable energy sources such as solar and wind require rapid load-leveling using high-power energy storage systems when they are integrated into a microgrid.Electrochemical energy storage devices efficiently convert electrical and chemical energy,which can potentially function as distributed power sources.Among these,lithium-ion batteries are a present de facto standard with their relatively high energy density and energy efficiencies that are based on topochemical intercalation chemistry,whereby vip lithium ions are(de)intercalated reversibly with simultaneous redox reactions and minimal structural changes.However,their energy density,power density,life-cycle cost,calendar life,and safety remain unsatisfactory for widespread use.When the storage capacity is maximized,as a result of which a labile deep charge/discharge state is generated,to develop batteries with high energy density,subsequent irreversible phase transformations or chemical reactions occur in many cases.The combination of the reversible electrode reactions and the subsequent irreversible phase transformations sometimes causes a charge/discharge curve characterized by a large voltage hysteresis with 100%Coulombic efficiency.Because a large voltage hysteresis significantly degrades the energy efficiency,unveiling the reaction mechanism is of primary importance in mitigating energy loss.
