We present a novel,low-cost optical sensor for accurate real-time monitoring of the state of charge(SoC)and total vanadium concentration in vanadium flow batteries.Using only six discrete wavelengths,the sensor achiev...We present a novel,low-cost optical sensor for accurate real-time monitoring of the state of charge(SoC)and total vanadium concentration in vanadium flow batteries.Using only six discrete wavelengths,the sensor achieves precision comparable to full-spectrum methods while significantly reducing equipment costs and complexity.A general deconvolution method is used to measure the SoC and the total vanadium concentration in both the negolyte and posolyte,with calibration covering concentrations from 1.21 to 1.82 mol/L.We achieve root mean square error(RMSE)values of 1.2%and 3.2%for the SoC,and 54 mmol/L and 97 mmol/L for the total vanadium concentration in the negolyte and posolyte,respectively,demonstrating excellent agreement with reference ultraviolet visible(UV-vis)data.In addition,a wavelength optimization study is proposed to determine the optimal number and placement of spectral channels,providing a basis for the design of tailored optical sensors for vanadium electrolytes.展开更多
To advance the theoretical understanding,technological development,and field application of electric charge induction for monitoring rock deformation and failure,this study investigates the induced electric charge gen...To advance the theoretical understanding,technological development,and field application of electric charge induction for monitoring rock deformation and failure,this study investigates the induced electric charge generated during the deformation and failure of igneous rocks.The charge originates mainly from a combination of electrical polarization and triboelectric effects.Through laboratory experiments,we analyzed the time-frequency evolution of induced electric charge signals and identified relevant monitoring parameters.An online downhole electric charge induction monitoring system was developed and validated in the field.Experimental results show that the dominant frequency range of induced electric charge signals generated during igneous rock deformation and failure lies between 0 and 23 Hz,and a low-pass finite impulse response(FIR)filter effectively suppresses noise.Optimal sensor distances for monitoring cubic and cylindrical specimens were determined to be 17 mm and 13 mm,respectively.We proposed early warning indicators,including the maximum absolute value of the induced electric charge,the arithmetic mean value,the distribution dispersion coefficient,and the cumulative sum value.In field application,time-domain curves and spatial distribution charts of these warning indicators correspond well with changes in abutment stress ahead of the mining face,offering indirect insights into local stress evolution.This research provides technical and equipment support for the application of electric charge induction technology to monitoring and early warning of coal bursts.展开更多
Effective monitoring techniques and equipment are essential for the prevention and control of coal and rockdynamic disasters such as rockburst. Based on the fact that there is charge generation during deformation andr...Effective monitoring techniques and equipment are essential for the prevention and control of coal and rockdynamic disasters such as rockburst. Based on the fact that there is charge generation during deformation andrupture of coal rock body and the charge signals contain a large amount of information about the mechanicalprocess of deformation and rupture of coal rock, the rockburst charge sensing monitoring technology has beenformed. In order to improve the charge sensing technology for monitoring and early warning of rockburst disasters, this paper develops a new generation of portable coal rock charge monitoring instrument on the basis ofthe original instrument and carries out laboratory and underground field application. The primary advancementinvolves enhancing the external structure of the sensor and increasing the charge sensing area, which can morecomprehensively capture the charge signals from the loaded rupture of the coal rock body. The overall structure ofthe data acquisition instrument has been improved, the monitoring channels have been increased, and thefunction of displaying the monitoring data curve has been added, so that the coal and rock body force status canbe grasped in time. The results of the experimental study show that the abnormal charge signals can be monitoredduring the rupture process of rock samples under loading, and the monitored charge signals are in good agreement with the sudden change of stress in the rock samples and the formation of crack extension. There is aprecursor charge signal before the stress mutation, and the larger the loading rate is, the earlier the precursorcharge signal appears. The charge monitoring instrument can monitor the charge signal of the coal seam roadwayunder strong mining pressure. In the zone of elevated overburden pressure, the amount of induced charge is large,and anomalously high value charge signals can be monitored when a coal shot occurs. The change trend of thecharge at different measuring points of strike and inclination has a good consistency with the distribution ofoverrunning support pressure and lateral support pressure, which can reflect the stress distribution and the degreeof stress concentration of the coal body through the size and location of the charge, foster early warning andanalysis of rockburst, and provide target guidance for the prevention and control of rockburst.展开更多
A coal-loaded charge induction monitoring system is developed to effectively forecast the dynamic disasters caused by coal failure.Specifically,a digital finite impulse response(FIR)filter is designed to denoise and f...A coal-loaded charge induction monitoring system is developed to effectively forecast the dynamic disasters caused by coal failure.Specifically,a digital finite impulse response(FIR)filter is designed to denoise and filter the signal,and the time-frequency domain evolution of induced charge signals is analyzed during coal failure experiments.The quantitative relationships between the induced electric charge and stress-strain energy,and ultimately,between induced electric charge and coal deformation/failure,are revealed.Ultimately,the electric charge sensor exhibits high signal collection frequency and high sensitivity,and the FIR low-pass filter constructed in MATLAB effectively denoises and filters induced charge signals.The main frequency range of the white noise is 50-500 Hz,and the main frequency of the charge signal induced by coal deformation and failure is concentrated in the range of 0-50 Hz.The optimal distances for monitoring cubic and cylindrical raw coal samples using this sensor are 9 mm and 11 mm,respectively.Notably,strain energy is released faster when it can dissipate more readily,and induced charge pulses become denser when more intense signals produce large fluctuations.A method is proposed to identify coal deformation and failure based on changes in the induced electric charge.This study provides a new means of monitoring the early warning signs of dynamic coal mine disasters.Based on our experimental results and conclusions,a new method is proposed to identify coal deformation and failure based on changes in the induced electric charge.The precursor to the moment of coal failure can be identified by monitoring the amplitude of the induced charge,the dynamic trend of fluctuation,and the cumulative number of induced electric charge pulses during the process of coal deformation.展开更多
Food waste treatment plants （FWTPs） are usually associated with odorous nuisance and health risks, which are partially caused by volatile organic compound （VOC） emissions. This study investigated the VOC emissions...Food waste treatment plants （FWTPs） are usually associated with odorous nuisance and health risks, which are partially caused by volatile organic compound （VOC） emissions. This study investigated the VOC emissions from a selected full-scale FWTP in China. The feedstock used in this plant was mainly collected from local restaurants. For a year, the FWTP was closely monitored on specific days in each season. Four major indoor treatment units of the plant, including the storage room, sorting/crushing room, hydrothermal hydrolysis unit, and aerobic fermentation unit, were chosen as the monitoring locations. The highest mean concentration of total VOC emissions was observed in the aerobic fermentation unit at 21,748.2-31,283.3 μg/m^3, followed by the hydrothermal hydrolysis unit at 10,798.1-23,144.4 μg/m^3. The detected VOC families included biogenic compounds （oxygenated compounds, hydrocarbons, terpenes, and organosulfur compounds） and abiogenic compounds （aromatic hydrocarbons and halocarbons）. Oxygenated compounds, particularly alcohols, were the most abundant compounds in all samples. With the use of odor index analysis and principal components analysis, the hydrothermal hydrolysis and aerobic fermentation units were clearly distinguished from the pre-treatment units, as characterized by their higher contributions to odorous nuisance. Methanthiol was the dominant odorant in the hydrothermal hydrolysis unit, whereas aldehyde was the dominant odorant in the aerobic fermentation unit. Terpenes, specifically limonene, had the highest level of propylene equivalent concentration during the monitoring periods. This concentration can contribute to the increase in the atmospheric reactivity and ozone formation potential in the surrounding air.展开更多
The deep dielectric charging effect monitor(DDCEM)has been designed to study the internal charging effect by measuring the charging currents and potentials inside the spacecraft.It is equipped on three Chinese navigat...The deep dielectric charging effect monitor(DDCEM)has been designed to study the internal charging effect by measuring the charging currents and potentials inside the spacecraft.It is equipped on three Chinese navigation satellites in a circular medium earth orbit(MEO)with 22000 km average height and 55°inclinations.Numerical simulation based on the Geant4-RIC method was used to evaluate the data of DDCEM.The data during May to November 2019 on one of the three satellites show that the charging currents of DDCEM were negatively enhanced when the satellite moved into the outer radiation belt.The currents reached the negative maximum during a significant electron enhancement in September 2019.Positive currents were also detected besides negative currents that were caused by the deposition of electrons in the sensor.The causation of positive currents in the space environment may be that the low-energy electrons cannot penetrate the satellite skin and make it charging to negative potential,the reference ground of DDCEM that is connected to the satellite skin drops below zero by the low-energy electrons so that the output currents turn to positive.Ground experiment was used to simulate the causation of positive currents and the result verified our theory.展开更多
基金supported by Grant TED2021-129378B-C21 funded by MICIU/AEI/10.13039/501100011033by the“European Union NextGenerationEU/PRTR”support of an MCSA-Cofund“Energy for Future”postdoctoral research fellowship(E4F)from the Spanish Iberdrola Foundation(GA101034297)。
文摘We present a novel,low-cost optical sensor for accurate real-time monitoring of the state of charge(SoC)and total vanadium concentration in vanadium flow batteries.Using only six discrete wavelengths,the sensor achieves precision comparable to full-spectrum methods while significantly reducing equipment costs and complexity.A general deconvolution method is used to measure the SoC and the total vanadium concentration in both the negolyte and posolyte,with calibration covering concentrations from 1.21 to 1.82 mol/L.We achieve root mean square error(RMSE)values of 1.2%and 3.2%for the SoC,and 54 mmol/L and 97 mmol/L for the total vanadium concentration in the negolyte and posolyte,respectively,demonstrating excellent agreement with reference ultraviolet visible(UV-vis)data.In addition,a wavelength optimization study is proposed to determine the optimal number and placement of spectral channels,providing a basis for the design of tailored optical sensors for vanadium electrolytes.
基金supported by the National Key Research and Development Project of the National Natural Science Foundation of China(Grant No.2022YFC3004605)the National Natural Science Foundation of China Youth Science Fund(Grant No.52104087).
文摘To advance the theoretical understanding,technological development,and field application of electric charge induction for monitoring rock deformation and failure,this study investigates the induced electric charge generated during the deformation and failure of igneous rocks.The charge originates mainly from a combination of electrical polarization and triboelectric effects.Through laboratory experiments,we analyzed the time-frequency evolution of induced electric charge signals and identified relevant monitoring parameters.An online downhole electric charge induction monitoring system was developed and validated in the field.Experimental results show that the dominant frequency range of induced electric charge signals generated during igneous rock deformation and failure lies between 0 and 23 Hz,and a low-pass finite impulse response(FIR)filter effectively suppresses noise.Optimal sensor distances for monitoring cubic and cylindrical specimens were determined to be 17 mm and 13 mm,respectively.We proposed early warning indicators,including the maximum absolute value of the induced electric charge,the arithmetic mean value,the distribution dispersion coefficient,and the cumulative sum value.In field application,time-domain curves and spatial distribution charts of these warning indicators correspond well with changes in abutment stress ahead of the mining face,offering indirect insights into local stress evolution.This research provides technical and equipment support for the application of electric charge induction technology to monitoring and early warning of coal bursts.
基金support of the National Natural Science Foundation of China(Grant no.52304219,52374201)the Liaoning Provincial Science and Technology Plan Project(Grant no.2022-BS-117)Open Project of Liaoning Technical University Liaoning Province Key Laboratory of Mining Environment and Disaster Mechanics(Grant no.MEDM2023-B-5).
文摘Effective monitoring techniques and equipment are essential for the prevention and control of coal and rockdynamic disasters such as rockburst. Based on the fact that there is charge generation during deformation andrupture of coal rock body and the charge signals contain a large amount of information about the mechanicalprocess of deformation and rupture of coal rock, the rockburst charge sensing monitoring technology has beenformed. In order to improve the charge sensing technology for monitoring and early warning of rockburst disasters, this paper develops a new generation of portable coal rock charge monitoring instrument on the basis ofthe original instrument and carries out laboratory and underground field application. The primary advancementinvolves enhancing the external structure of the sensor and increasing the charge sensing area, which can morecomprehensively capture the charge signals from the loaded rupture of the coal rock body. The overall structure ofthe data acquisition instrument has been improved, the monitoring channels have been increased, and thefunction of displaying the monitoring data curve has been added, so that the coal and rock body force status canbe grasped in time. The results of the experimental study show that the abnormal charge signals can be monitoredduring the rupture process of rock samples under loading, and the monitored charge signals are in good agreement with the sudden change of stress in the rock samples and the formation of crack extension. There is aprecursor charge signal before the stress mutation, and the larger the loading rate is, the earlier the precursorcharge signal appears. The charge monitoring instrument can monitor the charge signal of the coal seam roadwayunder strong mining pressure. In the zone of elevated overburden pressure, the amount of induced charge is large,and anomalously high value charge signals can be monitored when a coal shot occurs. The change trend of thecharge at different measuring points of strike and inclination has a good consistency with the distribution ofoverrunning support pressure and lateral support pressure, which can reflect the stress distribution and the degreeof stress concentration of the coal body through the size and location of the charge, foster early warning andanalysis of rockburst, and provide target guidance for the prevention and control of rockburst.
基金supported by the National Key Research and Development Project of the National Natural Science Foundation(Grant No.2022YFC3004605)the National Natural Science Foundation of China Youth Science Fund(Grant No.52104087).
文摘A coal-loaded charge induction monitoring system is developed to effectively forecast the dynamic disasters caused by coal failure.Specifically,a digital finite impulse response(FIR)filter is designed to denoise and filter the signal,and the time-frequency domain evolution of induced charge signals is analyzed during coal failure experiments.The quantitative relationships between the induced electric charge and stress-strain energy,and ultimately,between induced electric charge and coal deformation/failure,are revealed.Ultimately,the electric charge sensor exhibits high signal collection frequency and high sensitivity,and the FIR low-pass filter constructed in MATLAB effectively denoises and filters induced charge signals.The main frequency range of the white noise is 50-500 Hz,and the main frequency of the charge signal induced by coal deformation and failure is concentrated in the range of 0-50 Hz.The optimal distances for monitoring cubic and cylindrical raw coal samples using this sensor are 9 mm and 11 mm,respectively.Notably,strain energy is released faster when it can dissipate more readily,and induced charge pulses become denser when more intense signals produce large fluctuations.A method is proposed to identify coal deformation and failure based on changes in the induced electric charge.This study provides a new means of monitoring the early warning signs of dynamic coal mine disasters.Based on our experimental results and conclusions,a new method is proposed to identify coal deformation and failure based on changes in the induced electric charge.The precursor to the moment of coal failure can be identified by monitoring the amplitude of the induced charge,the dynamic trend of fluctuation,and the cumulative number of induced electric charge pulses during the process of coal deformation.
基金supported by the Environmental Protection Public Welfare Project (No. 201109035)
文摘Food waste treatment plants （FWTPs） are usually associated with odorous nuisance and health risks, which are partially caused by volatile organic compound （VOC） emissions. This study investigated the VOC emissions from a selected full-scale FWTP in China. The feedstock used in this plant was mainly collected from local restaurants. For a year, the FWTP was closely monitored on specific days in each season. Four major indoor treatment units of the plant, including the storage room, sorting/crushing room, hydrothermal hydrolysis unit, and aerobic fermentation unit, were chosen as the monitoring locations. The highest mean concentration of total VOC emissions was observed in the aerobic fermentation unit at 21,748.2-31,283.3 μg/m^3, followed by the hydrothermal hydrolysis unit at 10,798.1-23,144.4 μg/m^3. The detected VOC families included biogenic compounds （oxygenated compounds, hydrocarbons, terpenes, and organosulfur compounds） and abiogenic compounds （aromatic hydrocarbons and halocarbons）. Oxygenated compounds, particularly alcohols, were the most abundant compounds in all samples. With the use of odor index analysis and principal components analysis, the hydrothermal hydrolysis and aerobic fermentation units were clearly distinguished from the pre-treatment units, as characterized by their higher contributions to odorous nuisance. Methanthiol was the dominant odorant in the hydrothermal hydrolysis unit, whereas aldehyde was the dominant odorant in the aerobic fermentation unit. Terpenes, specifically limonene, had the highest level of propylene equivalent concentration during the monitoring periods. This concentration can contribute to the increase in the atmospheric reactivity and ozone formation potential in the surrounding air.
基金supported by the National Natural Science Foundation of China (Grant No. 41374181)the Beijing Municipal Natural Science Foundation (Grant No. 3184048)
文摘The deep dielectric charging effect monitor(DDCEM)has been designed to study the internal charging effect by measuring the charging currents and potentials inside the spacecraft.It is equipped on three Chinese navigation satellites in a circular medium earth orbit(MEO)with 22000 km average height and 55°inclinations.Numerical simulation based on the Geant4-RIC method was used to evaluate the data of DDCEM.The data during May to November 2019 on one of the three satellites show that the charging currents of DDCEM were negatively enhanced when the satellite moved into the outer radiation belt.The currents reached the negative maximum during a significant electron enhancement in September 2019.Positive currents were also detected besides negative currents that were caused by the deposition of electrons in the sensor.The causation of positive currents in the space environment may be that the low-energy electrons cannot penetrate the satellite skin and make it charging to negative potential,the reference ground of DDCEM that is connected to the satellite skin drops below zero by the low-energy electrons so that the output currents turn to positive.Ground experiment was used to simulate the causation of positive currents and the result verified our theory.
