Thermal effects of ultrasonically excited grinding fluid
72 In this study, to reveal reason of improvements by ultrasonic excited fluid , the amount of grinding fluid is measured. The amount is increased by the ultrasonic vibrations in case of fluid supply is small and the grinding wheel speed is higher. Moreover, the temperature at the grinding point is measured by constructing a thermocouple, it was confirmed that the grinding heat is reduced by using the ultrasonic excited fluid. And the effect of removing a grinding heat is due to the effect of the grinding fluid volume increased to grinding point. And, longer chip obtained with ultrasonic excited fluid compared with ordinary fluid. It shows suppression of wear of the abrasive grains with ultrasonic excited fluid Normal 0 0 2 false false false EN-US JA TA 72 In this study, to reveal reason of improvements by ultrasonic excited fluid , the amount of grinding fluid is measured. The amount is increased by the ultrasonic vibrations in case of fluid supply is small and the grinding wheel speed is higher. Moreover, the temperature at the grinding point is measured by constructing a thermocouple, it was confirmed that the grinding heat is reduced by using the ultrasonic excited fluid. And the effect of removing a grinding heat is due to the effect of the grinding fluid volume increased to grinding point. And, longer chip obtained with ultrasonic excited fluid compared with ordinary fluid. It shows suppression of wear of the abrasive grains with ultrasonic excited fluid Normal 0 0 2 false false false EN-US JA TA
Experimental Verification of Effect of Grinding Fluid Excited by Ultrasonic Vibration
The grinding performance is strongly affected by grain condition. Especially loading directly raises the grinding force, reduces tool life and deteriorates accuracy of machining. In this study, ultrasonic exciter which applies vibration energy on grinding fluid was developed. The resonant frequency of 28kHz. The exciter is set between the fluid supplying nozzle and grinding wheel. The discharging grinding fluid from the nozzle is supplied to grinding wheel between the teeth of comb-shape horn. The performance is verified on surface grinding machine with vitrified WA grinding wheel. It was experimentally demonstrated that the excited grinding fluid prevented the loading and improved the surface roughness even for grinding of aluminum. And also improvement of surface roughness was recognized on alloy tool steel.
UV-B radiometry and dosimetry for solar measurements.
Biologically effective irradiance or dose of solar UV radiation was determined using a spectroradiometer, two broadband radiometers and two types of passive UV-dosimeters. The absolute erythema irradiance and the actinic irradiance were calculated from the solar spectrum measured with the spectroradiometer. It was demonstrated that the erythema irradiance is proportional to the actinic irradiance of solar radiation. The erythema irradiance was also determined using the two broadband radiometers which utilize a filter transmitting erythema spectra. Personal UV-dosimeters such as polysulphone and CR-39 were used to determine the erythema dose for a selected period of time. These results were used to estimate the accuracy of the broadband radiometers and UV-dosimeters. It was found that the results obtained from the broadband radiometers deviate from the absolute erythema irradiance by less than 20% during clear days between the hours of 11:00 and 13:00 Eastern Standard Time (EST) in Australia. The assessment of the erythema dose using passive dosimeters such as polysulphone and CR-39 could introduce an error as high as 40% if the calibration was not performed before undertaking experimental measurements.