A solar PV panel works with maximum efficiency only when it is operated around its optimum operating point or maximum power point.Unfortunately,the performance of the solar cell is affected by several factors like sun...A solar PV panel works with maximum efficiency only when it is operated around its optimum operating point or maximum power point.Unfortunately,the performance of the solar cell is affected by several factors like sun direction,solar irradiance,dust accumulation,module temperature,as well as the load on the system.Dust deposition is one of the most prominent factors that influence the performance of solar panels.Because the solar panel is exposed to the atmosphere,dust will accumulate on its surface,reducing the quantity of sunlight reaching the solar cell and diminishing output.In the proposed work,a detailed investigation of the performance of solar PV modules is carried out under the tropical climatic condition of Chennai,India,where the presence of dust particles is very high.The data corresponding to four different dust samples of various densities at four solar irradiation levels of 220,525,702,and 905 W/m^(2)are collected,and performance analysis is carried out.Based on the analysis carried out,the maximum power loss is found to be 73.51%,66.29%,65.46%,and 61.42%,for coal,sand,brick powder,and chalk dust respectively.Hence,it can be said that coal dust contributes to the maximum power loss among all four dust samples.Due to heat dissipation produced by dust deposition,the performance of solar PV modules is degraded as the temperature rose.展开更多
Bisphenol A(BPA)is a high production volume(HPV)chemical used to make polycarbonate(PC)plastics and epoxy resins.Due to its potential adverse health effects,BPA has been restricted or banned in some products and thus ...Bisphenol A(BPA)is a high production volume(HPV)chemical used to make polycarbonate(PC)plastics and epoxy resins.Due to its potential adverse health effects,BPA has been restricted or banned in some products and thus many alternatives to BPA have been introduced into the market.Most of these alternatives such as bisphenol S(BPS),bisphenol F(BPF),and bisphenol M(BPM),have similar chemical structures to BPA and termed as BPA analogues(BPAAs).In this study,a method was developed for the simultaneous determination of 16 BPAAs in indoor dust by gas chromatography coupled with tandem mass spectrometry(GC-MS/MS).The method was sensitive,with method detection limits(MDLs)ranging from 0.001 mg/g to 0.017 mg/g.The method demonstrated good recoveries(>80%)for the majority of the target compounds and was applied to the analysis of dust samples collected from 2007 to 2010 in 13 cities across Canada under the Canadian House Dust Study(CHDS).Samples were collected using two different techniques:household vacuum dust samples collected from household vacuum bags(HD);fresh vacuum dust(FD)samples collected by a trained technician from dry floor surfaces.In addition to BPA with 100%detection in 119 HD samples,BPS,BPF,and BPM were detected with high detection frequencies(>75%)with median(range)concentrations of 0.242(<0.017-35.1)mg/g,0.123(<0.007-2.67)mg/g,and 0.028(<0.005-0.908)mg/g,respectively,suggesting their wide use in various applications.Other BPAAs were not detected or detected with very low frequencies and at low levels.This study shows that BPAA concentrations in dust sampled from household vacuum bags compare well with concentrations observed in fresh dust collected from the same homes,suggesting that HD sampling could be a cost-effective alternative to FD sampling.The method was also applied to the analysis of a standard reference material e NIST SRM 2585(organic contaminants in house dust).So far there are no certified values for BPAAs in SRM 2585.In this study only three BPAAs were detected in SRM 2585,with mean values of 34.2(±2.3)mg/g for BPA,1.88(±0.22)mg/g for BPS,and 0.297(±0.052)mg/g for BPF.展开更多
文摘A solar PV panel works with maximum efficiency only when it is operated around its optimum operating point or maximum power point.Unfortunately,the performance of the solar cell is affected by several factors like sun direction,solar irradiance,dust accumulation,module temperature,as well as the load on the system.Dust deposition is one of the most prominent factors that influence the performance of solar panels.Because the solar panel is exposed to the atmosphere,dust will accumulate on its surface,reducing the quantity of sunlight reaching the solar cell and diminishing output.In the proposed work,a detailed investigation of the performance of solar PV modules is carried out under the tropical climatic condition of Chennai,India,where the presence of dust particles is very high.The data corresponding to four different dust samples of various densities at four solar irradiation levels of 220,525,702,and 905 W/m^(2)are collected,and performance analysis is carried out.Based on the analysis carried out,the maximum power loss is found to be 73.51%,66.29%,65.46%,and 61.42%,for coal,sand,brick powder,and chalk dust respectively.Hence,it can be said that coal dust contributes to the maximum power loss among all four dust samples.Due to heat dissipation produced by dust deposition,the performance of solar PV modules is degraded as the temperature rose.
文摘Bisphenol A(BPA)is a high production volume(HPV)chemical used to make polycarbonate(PC)plastics and epoxy resins.Due to its potential adverse health effects,BPA has been restricted or banned in some products and thus many alternatives to BPA have been introduced into the market.Most of these alternatives such as bisphenol S(BPS),bisphenol F(BPF),and bisphenol M(BPM),have similar chemical structures to BPA and termed as BPA analogues(BPAAs).In this study,a method was developed for the simultaneous determination of 16 BPAAs in indoor dust by gas chromatography coupled with tandem mass spectrometry(GC-MS/MS).The method was sensitive,with method detection limits(MDLs)ranging from 0.001 mg/g to 0.017 mg/g.The method demonstrated good recoveries(>80%)for the majority of the target compounds and was applied to the analysis of dust samples collected from 2007 to 2010 in 13 cities across Canada under the Canadian House Dust Study(CHDS).Samples were collected using two different techniques:household vacuum dust samples collected from household vacuum bags(HD);fresh vacuum dust(FD)samples collected by a trained technician from dry floor surfaces.In addition to BPA with 100%detection in 119 HD samples,BPS,BPF,and BPM were detected with high detection frequencies(>75%)with median(range)concentrations of 0.242(<0.017-35.1)mg/g,0.123(<0.007-2.67)mg/g,and 0.028(<0.005-0.908)mg/g,respectively,suggesting their wide use in various applications.Other BPAAs were not detected or detected with very low frequencies and at low levels.This study shows that BPAA concentrations in dust sampled from household vacuum bags compare well with concentrations observed in fresh dust collected from the same homes,suggesting that HD sampling could be a cost-effective alternative to FD sampling.The method was also applied to the analysis of a standard reference material e NIST SRM 2585(organic contaminants in house dust).So far there are no certified values for BPAAs in SRM 2585.In this study only three BPAAs were detected in SRM 2585,with mean values of 34.2(±2.3)mg/g for BPA,1.88(±0.22)mg/g for BPS,and 0.297(±0.052)mg/g for BPF.