Using the ionic liquid[emim][Tf2N]as a physical solvent,it was found by Aspen Plus simulation that it was possible to attempt to capture CO2 from the flue gas discharged from the coal-fired unit of the power plant.Usi...Using the ionic liquid[emim][Tf2N]as a physical solvent,it was found by Aspen Plus simulation that it was possible to attempt to capture CO2 from the flue gas discharged from the coal-fired unit of the power plant.Using the combination of model calculation and experimental determination,the density,isostatic heat capacity,viscosity,vapor pressure,thermal conductivity,surface tension and solubility of[emim][Tf2N]were obtained.Based on the NRTL model,the Henry coefficient and NRTL binary interaction parameters of CO2 dissolved in[emim][Tf2N]were obtained by correlating[emim][Tf2N]with the gas–liquid equilibrium data of CO2.Firstly,the calculated relevant data is imported into Aspen Plus,and the whole process model of the ionic liquid absorption process is established.Then the absorption process is optimized according to the temperature distribution in the absorption tower to obtain a new absorption process.Finally,the density,constant pressure heat capacity,surface tension,thermal conductivity,and viscosity of[emim][Tf2N]were changed to investigate the effect of ionic liquid properties on process energy consumption,solvent circulation and heat exchanger design.The results showed that based on the composition of the inlet gas stream to the absorbers,CO2 with a capture rate of 90%and a mass purity higher than 99.5%was captured.These results indicate that the[emim][Tf2N]could be used as a physical solvent for CO2 capture from coal-fired units.In addition,the results will provide a theoretical basis for the design of new ionic liquids for CO2 capture.展开更多
An on-line electric vehicle(OLEV)uses a wireless charging phenomenon,in which power transmitters are installed beneath the road and the OLEV’s battery is charged remotely.This paper deals with the optimization of two...An on-line electric vehicle(OLEV)uses a wireless charging phenomenon,in which power transmitters are installed beneath the road and the OLEV’s battery is charged remotely.This paper deals with the optimization of two key economic and design parameters,i.e.,the size of the battery and the power transmitters allocation.A complete model configuration of the OLEV system,including the vehicle design and power transmitter,is implemented using MATLAB/Simulink.The battery’s state of charge(SOC)rises and drops according to the vehicle’s velocity and power collection and consumption.The mixed integer programming(MIP)model is used for cost calculation.Therefore,with the help of the SOC graph and MIP model,the battery size and the number of power transmitters,along with their placements,are optimized.The proposed model is applicable to both closed and open environments as it accepts both regulated and deregulated velocities.Two test cases are performed for this purpose.The first test case deals with regulated velocity for which we have applied the KAIST campus OLEV’s velocity along with its 13 kWh battery size and 4 power transmitters,and then applied the suggested solution with the same velocity and route i.e.,8 power transmitters with shorter lengths and reduced battery size(3.25 kWh;one-fourth of the first case).SOC is found within limits at the end of the route,saving$1600 and validating the proposed model in this paper.For the second test case,we use deregulated velocity and optimize both parameters,using the same approach.展开更多
The microenvironment,which involves pollutant dispersion of the urban street canyon,is critical to the health of pedestrians and residents.The objectives of this work are twofold:(i)to effectively assess the pollutant...The microenvironment,which involves pollutant dispersion of the urban street canyon,is critical to the health of pedestrians and residents.The objectives of this work are twofold:(i)to effectively assess the pollutant dispersion process based on a theory and(ii)to adopt an appropriate stratigy,i.e.,wind catcher,to alleviate the pollution in the street canyons.Pollutant dispersion in street canyons is essentially a convective mass transfer process.Because the convective heat transfer process and the mass transfer process are physically similar and the applicability of field synergy theory to turbulence has been verified in the literature,we apply the field synergy theory to the study of pollutant dispersion in street canyons.In this paper,a computational fluid dynamics(CFD)simulation is conducted to investigate the effects of wind catcher,wind speed and the geometry of the street canyons on pollutant dispersion.According to the field synergy theory,Sherwood number and field synergy number are used to quantitatively evaluate the wind catcher and wind speed on the diffusion of pollutants in asymmetric street canyons.The results show that adding wind catchers can significantly improve the air quality of the step-down street canyon and reduce the average pollutant concentrations in the street canyon by 75%.Higher wind speed enhances diffusion of pollutants differently in different geometric street canyons.展开更多
The multifunctional properties of carbon nanotubes(CNTs)make them a powerful platform for unprecedented innovations in a variety of practical applications.As a result of the surging growth of nanotechnology,nanotubes ...The multifunctional properties of carbon nanotubes(CNTs)make them a powerful platform for unprecedented innovations in a variety of practical applications.As a result of the surging growth of nanotechnology,nanotubes present a potential problem as an environmental pollutant,and as such,an efficient method for their rapid detection must be established.Here,we propose a novel type of ionic sensor complex for detecting CNTs–an organic dye that responds sensitively and selectively to CNTs with a photoluminescent signal.The complexes are formed through Coulomb attractions between dye molecules with uncompensated charges and CNTs covered with an ionic surfactant in water.We demonstrate that the photoluminescent excitation of the dye can be transferred to the nanotubes,resulting in selective and strong amplification(up to a factor of 6)of the light emission from the excitonic levels of CNTs in the near-infrared spectral range,as experimentally observed via excitation-emission photoluminescence(PL)mapping.The chirality of the nanotubes and the type of ionic surfactant used to disperse the nanotubes both strongly affect the amplification;thus,the complexation provides sensing selectivity towards specific CNTs.Additionally,neither similar uncharged dyes nor CNTs covered with neutral surfactant form such complexes.As model organic molecules,we use a family of polymethine dyes with an easily tailorable molecular structure and,consequently,tunable absorbance and PL characteristics.This provides us with a versatile tool for the controllable photonic and electronic engineering of an efficient probe for CNT detection.展开更多
A precise energy conversion factor is required to define the impact of greenhouse gas emissions by gasoline-powered vehi-cles and policies that will guide the application of future eco-innovations.The current energy c...A precise energy conversion factor is required to define the impact of greenhouse gas emissions by gasoline-powered vehi-cles and policies that will guide the application of future eco-innovations.The current energy conversion factor adopted by many countries is based on the Willans line approach,initially proposed in 1888 for steam engines,later adapted for internal combustion engines.The actual energy conversion factor,which defines the energy conversion for drivers in real traffic,is missing.In this article,eight world-class engines are tested in an engine bench for the acquisition of specific fuel consumption 3D maps.Then,their energy conversion factors,calculated by dividing the energy output by the energy input,are simulated in real and urban traffic,acquired according to the real driving emissions(RDE)cycle.In addition,a reference vehicle is instrumented to measure the energy input(fuel flow)and the energy output(mechanical energy in the half axles)under the same RDE cycle standards.The results of both procedures are very similar,respectively,0.405±0.04 L/kWh for the simulation based on eight benchmark engines,and 0.392±0.04 L/kWh for the reference vehicle driven in RDE traffic conditions,with a 95%confidence interval.For turbocharged engines,the factor attained by the simulation is 0.395±0.04 L/kWh.The values of the energy conversion factor for gasoline engines got in this research are higher than those obtained through the Willans line approach,suggesting a new standard value of 0.405 L/kWh,replacing the current 0.264 L/kWh.It could substantially change the greenhouse gas emissions in a tank-to-wheel approach for the entire vehicle and add-on eco-innovations.展开更多
Nerve injury requiring surgical repair often results in poor functional recovery due to the inability of host axons to re-grow long distances and reform meaningful connections with the target muscle. While surgeons ca...Nerve injury requiring surgical repair often results in poor functional recovery due to the inability of host axons to re-grow long distances and reform meaningful connections with the target muscle. While surgeons can re-route local axon fascicles to the target muscle, there are no technologies to provide an exogenous source of axons without sacrificing healthy nerves. Accordingly, we have developed tissue engineered neuromuscular interfaces (TE-NMIs) as the first injectable microtissue containing motor and sensory neurons in an anatomically-inspired architecture. TE-NMIs provide axon tracts that are intended to integrate with denervated distal structures and preserve regenerative capacity during prolonged periods without host innervation. Following implant, we found that TE-NMI axons promoted Schwann cell maintenance, integrated with distal muscle, and preserved an evoked muscle response out to 20-weeks post nerve transection in absence of innervation from host axons. By repopulating the distal sheath with exogenous axons, TE-NMIs also enabled putative delayed fusion with proximal host axons, a phenomenon previously not achievable in delayed repair scenarios due to distal axon degeneration. Here, we found immediate electrophysiological recovery after fusion with proximal host axons and improved axon maturation and muscle reinnervation at 24-weeks post-transection (4-weeks following delayed nerve fusion). These findings show that TE-NMIs provide the potential to improve functional recovery following delayed nerve repair.展开更多
基金financially supported by the Zhejiang Provincial Natural Science Foundation of China(LY16B060014)State Key Laboratory of Chemical Engineering(No.SKL-ChE-08A01)the Innovation and Development of Marine Economy Demonstration。
文摘Using the ionic liquid[emim][Tf2N]as a physical solvent,it was found by Aspen Plus simulation that it was possible to attempt to capture CO2 from the flue gas discharged from the coal-fired unit of the power plant.Using the combination of model calculation and experimental determination,the density,isostatic heat capacity,viscosity,vapor pressure,thermal conductivity,surface tension and solubility of[emim][Tf2N]were obtained.Based on the NRTL model,the Henry coefficient and NRTL binary interaction parameters of CO2 dissolved in[emim][Tf2N]were obtained by correlating[emim][Tf2N]with the gas–liquid equilibrium data of CO2.Firstly,the calculated relevant data is imported into Aspen Plus,and the whole process model of the ionic liquid absorption process is established.Then the absorption process is optimized according to the temperature distribution in the absorption tower to obtain a new absorption process.Finally,the density,constant pressure heat capacity,surface tension,thermal conductivity,and viscosity of[emim][Tf2N]were changed to investigate the effect of ionic liquid properties on process energy consumption,solvent circulation and heat exchanger design.The results showed that based on the composition of the inlet gas stream to the absorbers,CO2 with a capture rate of 90%and a mass purity higher than 99.5%was captured.These results indicate that the[emim][Tf2N]could be used as a physical solvent for CO2 capture from coal-fired units.In addition,the results will provide a theoretical basis for the design of new ionic liquids for CO2 capture.
文摘An on-line electric vehicle(OLEV)uses a wireless charging phenomenon,in which power transmitters are installed beneath the road and the OLEV’s battery is charged remotely.This paper deals with the optimization of two key economic and design parameters,i.e.,the size of the battery and the power transmitters allocation.A complete model configuration of the OLEV system,including the vehicle design and power transmitter,is implemented using MATLAB/Simulink.The battery’s state of charge(SOC)rises and drops according to the vehicle’s velocity and power collection and consumption.The mixed integer programming(MIP)model is used for cost calculation.Therefore,with the help of the SOC graph and MIP model,the battery size and the number of power transmitters,along with their placements,are optimized.The proposed model is applicable to both closed and open environments as it accepts both regulated and deregulated velocities.Two test cases are performed for this purpose.The first test case deals with regulated velocity for which we have applied the KAIST campus OLEV’s velocity along with its 13 kWh battery size and 4 power transmitters,and then applied the suggested solution with the same velocity and route i.e.,8 power transmitters with shorter lengths and reduced battery size(3.25 kWh;one-fourth of the first case).SOC is found within limits at the end of the route,saving$1600 and validating the proposed model in this paper.For the second test case,we use deregulated velocity and optimize both parameters,using the same approach.
基金This research was supported by the National Natural Science Foundation of China(Grant No.51778511)the European Commission H2020 Marie S Curie Research and Innovation Staff Exchange(RISE)award(Grant No.871998)+2 种基金Hubei Provincial Natural Science Foundation of China(Grant No.2018CFA029)Key Project of ESI Discipline Development of Wuhan University of Technology(Grant No.2017001)the Fundamental Research Funds for the Central Universities(Grant No.2019IVB082).
文摘The microenvironment,which involves pollutant dispersion of the urban street canyon,is critical to the health of pedestrians and residents.The objectives of this work are twofold:(i)to effectively assess the pollutant dispersion process based on a theory and(ii)to adopt an appropriate stratigy,i.e.,wind catcher,to alleviate the pollution in the street canyons.Pollutant dispersion in street canyons is essentially a convective mass transfer process.Because the convective heat transfer process and the mass transfer process are physically similar and the applicability of field synergy theory to turbulence has been verified in the literature,we apply the field synergy theory to the study of pollutant dispersion in street canyons.In this paper,a computational fluid dynamics(CFD)simulation is conducted to investigate the effects of wind catcher,wind speed and the geometry of the street canyons on pollutant dispersion.According to the field synergy theory,Sherwood number and field synergy number are used to quantitatively evaluate the wind catcher and wind speed on the diffusion of pollutants in asymmetric street canyons.The results show that adding wind catchers can significantly improve the air quality of the step-down street canyon and reduce the average pollutant concentrations in the street canyon by 75%.Higher wind speed enhances diffusion of pollutants differently in different geometric street canyons.
基金supported by the NATO SPS Programme(NUKR.SFPP 984189 project)support from the Human Capacity Development Program of the Ministry of Higher Education and Scientific Research of the Iraq-Kurdistan Region。
文摘The multifunctional properties of carbon nanotubes(CNTs)make them a powerful platform for unprecedented innovations in a variety of practical applications.As a result of the surging growth of nanotechnology,nanotubes present a potential problem as an environmental pollutant,and as such,an efficient method for their rapid detection must be established.Here,we propose a novel type of ionic sensor complex for detecting CNTs–an organic dye that responds sensitively and selectively to CNTs with a photoluminescent signal.The complexes are formed through Coulomb attractions between dye molecules with uncompensated charges and CNTs covered with an ionic surfactant in water.We demonstrate that the photoluminescent excitation of the dye can be transferred to the nanotubes,resulting in selective and strong amplification(up to a factor of 6)of the light emission from the excitonic levels of CNTs in the near-infrared spectral range,as experimentally observed via excitation-emission photoluminescence(PL)mapping.The chirality of the nanotubes and the type of ionic surfactant used to disperse the nanotubes both strongly affect the amplification;thus,the complexation provides sensing selectivity towards specific CNTs.Additionally,neither similar uncharged dyes nor CNTs covered with neutral surfactant form such complexes.As model organic molecules,we use a family of polymethine dyes with an easily tailorable molecular structure and,consequently,tunable absorbance and PL characteristics.This provides us with a versatile tool for the controllable photonic and electronic engineering of an efficient probe for CNT detection.
基金The authors thank Brazilian Development BNDES for the economic support,the Joint Research Centre JRC for the technical assistance to this project and to Mr.Adam Aslam/Gabriel Santos for the grammar revision.
文摘A precise energy conversion factor is required to define the impact of greenhouse gas emissions by gasoline-powered vehi-cles and policies that will guide the application of future eco-innovations.The current energy conversion factor adopted by many countries is based on the Willans line approach,initially proposed in 1888 for steam engines,later adapted for internal combustion engines.The actual energy conversion factor,which defines the energy conversion for drivers in real traffic,is missing.In this article,eight world-class engines are tested in an engine bench for the acquisition of specific fuel consumption 3D maps.Then,their energy conversion factors,calculated by dividing the energy output by the energy input,are simulated in real and urban traffic,acquired according to the real driving emissions(RDE)cycle.In addition,a reference vehicle is instrumented to measure the energy input(fuel flow)and the energy output(mechanical energy in the half axles)under the same RDE cycle standards.The results of both procedures are very similar,respectively,0.405±0.04 L/kWh for the simulation based on eight benchmark engines,and 0.392±0.04 L/kWh for the reference vehicle driven in RDE traffic conditions,with a 95%confidence interval.For turbocharged engines,the factor attained by the simulation is 0.395±0.04 L/kWh.The values of the energy conversion factor for gasoline engines got in this research are higher than those obtained through the Willans line approach,suggesting a new standard value of 0.405 L/kWh,replacing the current 0.264 L/kWh.It could substantially change the greenhouse gas emissions in a tank-to-wheel approach for the entire vehicle and add-on eco-innovations.
基金The authors would like to thank Elizabeth Boyle for technical support.Financial support provided by the U.S.Department of Defense[CDMRP/JPC8-CRMRP W81XWH-16-1-0796(Cullen)&CDMRP/PRORP W81XWH-19-1-0867(Cullen&Das)]the Department of Veterans Affairs[BLR&D Merit Review I01-BX003748(Cullen)]+2 种基金the National Institutes of Health[R44-NS108869(Katiyar&Cullen)T32-EB005583(Shultz),TL1-TR001880(Burrell)]the Center for Undergraduate Research and Fellowships at the University of Pennsylvania.Opinions,interpretations,conclusions and recommendations are those of the author(s)and are not necessarily endorsed by the Department of Defense,the Department of Veterans Affairs,or the National Institutes of Health.
文摘Nerve injury requiring surgical repair often results in poor functional recovery due to the inability of host axons to re-grow long distances and reform meaningful connections with the target muscle. While surgeons can re-route local axon fascicles to the target muscle, there are no technologies to provide an exogenous source of axons without sacrificing healthy nerves. Accordingly, we have developed tissue engineered neuromuscular interfaces (TE-NMIs) as the first injectable microtissue containing motor and sensory neurons in an anatomically-inspired architecture. TE-NMIs provide axon tracts that are intended to integrate with denervated distal structures and preserve regenerative capacity during prolonged periods without host innervation. Following implant, we found that TE-NMI axons promoted Schwann cell maintenance, integrated with distal muscle, and preserved an evoked muscle response out to 20-weeks post nerve transection in absence of innervation from host axons. By repopulating the distal sheath with exogenous axons, TE-NMIs also enabled putative delayed fusion with proximal host axons, a phenomenon previously not achievable in delayed repair scenarios due to distal axon degeneration. Here, we found immediate electrophysiological recovery after fusion with proximal host axons and improved axon maturation and muscle reinnervation at 24-weeks post-transection (4-weeks following delayed nerve fusion). These findings show that TE-NMIs provide the potential to improve functional recovery following delayed nerve repair.