There is little information about drivers’body balance responses to combined exposure of noise and vibration.To fill the gap,this study aims to investigate the combined effects of exposure to noise and whole-body vib...There is little information about drivers’body balance responses to combined exposure of noise and vibration.To fill the gap,this study aims to investigate the combined effects of exposure to noise and whole-body vibration(WBV)on the body balance under simulated driving conditions.For this purpose,30 male participants were exposed to noise level at 85 dB(A)and two vibration levels(0.87 and 1.3 m/s^(2))in five sessions.The design of the study was repeated-measures,and it attempted to assess the effects of 40 minutes of exposure to noise and/or WBV.Moreover,the participants’fatigue was measured with the Borg scale(CR 10).The findings revealed there was a significant change in body sway after WBV and combined noise and WBV exposure(p<0.05).However,no significant difference was found in exposure to noise alone(p>0.05).The effect sizes of exposure to noise,WBV(1.3 m/s^(2)),and combined noise and WBV(1.3 m/s^(2))on body balance were 0.035,0.425,and 0.635,respectively.Also,single exposure to WBV caused more fatigue than single exposure to noise(p<0.05).Combined noise and WBV exposure descriptively caused more fatigue in comparison with the influence of WBV alone.The study concluded that the combined effects of exposure to noise and vibration are more than the sum of them.So,some synergistic effects may be observed in human body balance.It is essential to increase drivers’awareness and revise current health care interventions about new possible effects of combined exposures.展开更多
Ultrasonic vibration technology has great potential to weaken hard rocks.Understanding the effect of ultrasonic vibration loading parameters is essential to accelerate the application of this technology in practical r...Ultrasonic vibration technology has great potential to weaken hard rocks.Understanding the effect of ultrasonic vibration loading parameters is essential to accelerate the application of this technology in practical rock engineering.In the present work,three-factor mixed-level orthogonal ultrasonic vibration rock breaking tests were conducted to investigate the influence of the main loading parameters,including confining pressure,vibration frequency,and static force,on the damage of granite specimens.The individual and combined influences were analyzed according to the porosity increase and P-wave decrease of granite specimens using the variance analysis method.The results show that the combined effect of the static force and vibration frequency mainly promotes fatigue damage of specimens,that the confining pressure determines the damage behaviour and failure mode of specimens under ultrasonic vibration,and that the confining pressure and vibration frequency are the main factors that cause the fracture concentration in the upper part of specimens,an effect mechanistically driven by the obvious load energy attenuation.The research results provide theoretical guidance for the application of ultrasonic vibration technology.展开更多
Combine harvesters are important in that grain and legumes directly affect the production economy.On the other hand,it forms an important branch of the agricultural machinery sector.There are many unknown constraints ...Combine harvesters are important in that grain and legumes directly affect the production economy.On the other hand,it forms an important branch of the agricultural machinery sector.There are many unknown constraints on machines when harvesting with a combine harvester,including the noise and vibration that occur in the combine harvester thresher.This study aims to analyze noise and vibration in conventional combine harvesters using sensors.Two accelerometers were installed on each side of the concave and two microphones were used to register the noise of the threshing process.The result showed that effects of machine speeds(3.5 km/h,4.5 km/h and 5.5 km/h)and rotor speeds(950 r/min,850 r/min and 950 r/min)were significantly important for the mean range values of the left and right accelerometer in the X,Y and Z direction.The machine’s speed and rotor speed were not significantly important for the mean range values of the left and right microphones.展开更多
基金This study was financially supported by Research Deputy of Hamadan University of Medical Sciences(Grant No.9802241621).We would like to appreciate the students of Hamadan University of Medical Sciences for their participation in this project。
文摘There is little information about drivers’body balance responses to combined exposure of noise and vibration.To fill the gap,this study aims to investigate the combined effects of exposure to noise and whole-body vibration(WBV)on the body balance under simulated driving conditions.For this purpose,30 male participants were exposed to noise level at 85 dB(A)and two vibration levels(0.87 and 1.3 m/s^(2))in five sessions.The design of the study was repeated-measures,and it attempted to assess the effects of 40 minutes of exposure to noise and/or WBV.Moreover,the participants’fatigue was measured with the Borg scale(CR 10).The findings revealed there was a significant change in body sway after WBV and combined noise and WBV exposure(p<0.05).However,no significant difference was found in exposure to noise alone(p>0.05).The effect sizes of exposure to noise,WBV(1.3 m/s^(2)),and combined noise and WBV(1.3 m/s^(2))on body balance were 0.035,0.425,and 0.635,respectively.Also,single exposure to WBV caused more fatigue than single exposure to noise(p<0.05).Combined noise and WBV exposure descriptively caused more fatigue in comparison with the influence of WBV alone.The study concluded that the combined effects of exposure to noise and vibration are more than the sum of them.So,some synergistic effects may be observed in human body balance.It is essential to increase drivers’awareness and revise current health care interventions about new possible effects of combined exposures.
基金This study was funded by the National Natural Science Foundation of China(Project Name:Research on mechanism of ultrasonic vibration breaking rock,Project No.41572356).
文摘Ultrasonic vibration technology has great potential to weaken hard rocks.Understanding the effect of ultrasonic vibration loading parameters is essential to accelerate the application of this technology in practical rock engineering.In the present work,three-factor mixed-level orthogonal ultrasonic vibration rock breaking tests were conducted to investigate the influence of the main loading parameters,including confining pressure,vibration frequency,and static force,on the damage of granite specimens.The individual and combined influences were analyzed according to the porosity increase and P-wave decrease of granite specimens using the variance analysis method.The results show that the combined effect of the static force and vibration frequency mainly promotes fatigue damage of specimens,that the confining pressure determines the damage behaviour and failure mode of specimens under ultrasonic vibration,and that the confining pressure and vibration frequency are the main factors that cause the fracture concentration in the upper part of specimens,an effect mechanistically driven by the obvious load energy attenuation.The research results provide theoretical guidance for the application of ultrasonic vibration technology.
文摘Combine harvesters are important in that grain and legumes directly affect the production economy.On the other hand,it forms an important branch of the agricultural machinery sector.There are many unknown constraints on machines when harvesting with a combine harvester,including the noise and vibration that occur in the combine harvester thresher.This study aims to analyze noise and vibration in conventional combine harvesters using sensors.Two accelerometers were installed on each side of the concave and two microphones were used to register the noise of the threshing process.The result showed that effects of machine speeds(3.5 km/h,4.5 km/h and 5.5 km/h)and rotor speeds(950 r/min,850 r/min and 950 r/min)were significantly important for the mean range values of the left and right accelerometer in the X,Y and Z direction.The machine’s speed and rotor speed were not significantly important for the mean range values of the left and right microphones.
