Based on the evaluation of advantages and disadvantages of high-precision digital time interval measuring algorithms, and combined with the principle of the typical time-difference ultrasonic flow measurement, the req...Based on the evaluation of advantages and disadvantages of high-precision digital time interval measuring algorithms, and combined with the principle of the typical time-difference ultrasonic flow measurement, the requirements for the measurement of echo time of flight put forward by the ultrasonic flow measurement are analyzed. A new high-precision time interval measurement algorithm is presented, which combines the pulse counting method with the phase delay interpolation. The pulse counting method is used to ensure a large dynamic measuring range, and a double-edge triggering counter is designed to improve the accuracy and reduce the counting quantization error. The phase delay interpolation is used to reduce the quantization error of pulse counting for further improving the time measurement resolution. Test data show that the systexn for the measurement of the ultrasonic echo time of flight based on this algorithm and implemented on an Field Programmable Gate Army（FleA） needs a relatively short time for measurement, and has a measurement error of less than 105 ps.展开更多
[ Objective] To optimize the ultrasonic-assisted extraction process of chlorogenic acid from sunflower meal. [ Method] Based on the sin-gle-factor test, the extraction factors of ethanol concentration, extraction temp...[ Objective] To optimize the ultrasonic-assisted extraction process of chlorogenic acid from sunflower meal. [ Method] Based on the sin-gle-factor test, the extraction factors of ethanol concentration, extraction temperature and extraction time were optimized using the response surface methodology with the extraction rate of chlorogenic acid as the response value. [ Result] The optimum extraction conditions of chlorogenic acid from sunflower meal were 57% of ethanol concentration, 39 min of extraction time, 53 ~C of extraction temperature, 100 W of ultrasonic power, 1 ： 14 （ g/ ml） of solid-liquid ratio and one time of extraction. Under these conditions, the extraction rate of chlorogenic acid was 2.25%. [ Conclusion] Ultra-sonic assisted extraction method has high extraction rate but short time, the study provides a theoretical basis for the industrialized production of chlorogenic acid in sunflower meal.展开更多
Ultrasound was applied for the extraction of pectin from chaenomeles. The content of pectin was evaluated by carbazole colorimetric method. Based on the results of the single factor experiment and the orthogonal tests...Ultrasound was applied for the extraction of pectin from chaenomeles. The content of pectin was evaluated by carbazole colorimetric method. Based on the results of the single factor experiment and the orthogonal tests, the optimum extraction parameters are as follows: the solid-to-liquid ratio is 1:4 g/m L, the ultrasonic power is 320 W, the ultrasonic-assisted extraction temperature is 60 °C, the ultrasonic-assisted extraction time is 50 min, and p H value is 2.0. Compared with acid hydrolyze methods, the extraction time of the present technique decreases from 70 min to 50 min, and the extraction yield increases from 1.39% to 2.61%. The results show that ultrasonic-assisted extraction is time-saving and highly efficient, so it provides a new way to extract pectin from chaenomeles.展开更多
Ultrasonic and jet combined process was studied to remove determined by static experiments, and stability of this combined process algae in lake type raw water. The optimum reaction time was was checked by dynamic exp...Ultrasonic and jet combined process was studied to remove determined by static experiments, and stability of this combined process algae in lake type raw water. The optimum reaction time was was checked by dynamic experiments. The results was showed that ultrasonic/jet combined process has excellent removal efficiency on algae in lake type raw water, and it＇s a simple operation, and has no secondary pollution. When the pH, temperature, chlorophyll-a（Chl-a） and cell concentration（OD560） of raw water are 7.69, 25.8 ℃, 29.003 mg/m^3 and 0.091, the average removal efficiency on Chl-a and OD560 are 81.60% and 80.22%, respectively, which are stable by this combined process when it is operating in 36 hours, and samples are analyzed each 4 hours.展开更多
Intensity of cavitation is significant in ultrasonic wastewater treatment,but is complicated to measure.A time difference based method of ultrasonic cavitation measurement is proposed.The time differences at different...Intensity of cavitation is significant in ultrasonic wastewater treatment,but is complicated to measure.A time difference based method of ultrasonic cavitation measurement is proposed.The time differences at different powers of 495 kHz ultrasonic are measured in experiment in comparison with conductimetric method.Simulation results show that time difference and electrical conductivity are both approximately positive proportional to the ultrasonic power.The degradation of PNP solution verifies the availability in wastewater treatment by using ultrasonic.展开更多
基金supported by the National 863 Program(No.2008AA042207)
文摘Based on the evaluation of advantages and disadvantages of high-precision digital time interval measuring algorithms, and combined with the principle of the typical time-difference ultrasonic flow measurement, the requirements for the measurement of echo time of flight put forward by the ultrasonic flow measurement are analyzed. A new high-precision time interval measurement algorithm is presented, which combines the pulse counting method with the phase delay interpolation. The pulse counting method is used to ensure a large dynamic measuring range, and a double-edge triggering counter is designed to improve the accuracy and reduce the counting quantization error. The phase delay interpolation is used to reduce the quantization error of pulse counting for further improving the time measurement resolution. Test data show that the systexn for the measurement of the ultrasonic echo time of flight based on this algorithm and implemented on an Field Programmable Gate Army（FleA） needs a relatively short time for measurement, and has a measurement error of less than 105 ps.
基金Supported by the Science and Technology Program of Jilin Education Department during the"Eleventh-Five Year Plan" (Jilin[2010]No.206)
文摘[ Objective] To optimize the ultrasonic-assisted extraction process of chlorogenic acid from sunflower meal. [ Method] Based on the sin-gle-factor test, the extraction factors of ethanol concentration, extraction temperature and extraction time were optimized using the response surface methodology with the extraction rate of chlorogenic acid as the response value. [ Result] The optimum extraction conditions of chlorogenic acid from sunflower meal were 57% of ethanol concentration, 39 min of extraction time, 53 ~C of extraction temperature, 100 W of ultrasonic power, 1 ： 14 （ g/ ml） of solid-liquid ratio and one time of extraction. Under these conditions, the extraction rate of chlorogenic acid was 2.25%. [ Conclusion] Ultra-sonic assisted extraction method has high extraction rate but short time, the study provides a theoretical basis for the industrialized production of chlorogenic acid in sunflower meal.
基金Project(2011ZK3171) supported by Hunan Provincial Science & Technology Department,China
文摘Ultrasound was applied for the extraction of pectin from chaenomeles. The content of pectin was evaluated by carbazole colorimetric method. Based on the results of the single factor experiment and the orthogonal tests, the optimum extraction parameters are as follows: the solid-to-liquid ratio is 1:4 g/m L, the ultrasonic power is 320 W, the ultrasonic-assisted extraction temperature is 60 °C, the ultrasonic-assisted extraction time is 50 min, and p H value is 2.0. Compared with acid hydrolyze methods, the extraction time of the present technique decreases from 70 min to 50 min, and the extraction yield increases from 1.39% to 2.61%. The results show that ultrasonic-assisted extraction is time-saving and highly efficient, so it provides a new way to extract pectin from chaenomeles.
文摘Ultrasonic and jet combined process was studied to remove determined by static experiments, and stability of this combined process algae in lake type raw water. The optimum reaction time was was checked by dynamic experiments. The results was showed that ultrasonic/jet combined process has excellent removal efficiency on algae in lake type raw water, and it＇s a simple operation, and has no secondary pollution. When the pH, temperature, chlorophyll-a（Chl-a） and cell concentration（OD560） of raw water are 7.69, 25.8 ℃, 29.003 mg/m^3 and 0.091, the average removal efficiency on Chl-a and OD560 are 81.60% and 80.22%, respectively, which are stable by this combined process when it is operating in 36 hours, and samples are analyzed each 4 hours.
基金Supported by the National Natural Science Foundation of China(No.11274092,11274091,11304026)the Fundamental Research Funds for the Central Universities(No.14B10128)
文摘Intensity of cavitation is significant in ultrasonic wastewater treatment,but is complicated to measure.A time difference based method of ultrasonic cavitation measurement is proposed.The time differences at different powers of 495 kHz ultrasonic are measured in experiment in comparison with conductimetric method.Simulation results show that time difference and electrical conductivity are both approximately positive proportional to the ultrasonic power.The degradation of PNP solution verifies the availability in wastewater treatment by using ultrasonic.
