In order to meet the high precision requirement of wide steel strip in industry field, a novel online measurement of roller profile based on sonic circulation and pulse-echo technology was introduced. All kinds of the...In order to meet the high precision requirement of wide steel strip in industry field, a novel online measurement of roller profile based on sonic circulation and pulse-echo technology was introduced. All kinds of the factors influencing the accuracy of roller profile online measurement were analyzed in detail and error compensation analysis of system was accordingly presented. In order to reduce count error, field program gate array(FPGA) was introduced and a highprecision data acquisition system was designed based on digital phase-shift technology. Experiments indicate that the standard deviation of measure data was 7.27 μm, which showed the feasibility and validity of the proposed method, and realized the roll profile measurement with high precision.展开更多
By means of ultrasonic attenuation apparatus, the ultrasonic velocity and attenuation ofanhydride-cured epoxy resins (EP)/poly (ethylene oxide) (PEO) blends were measured on thebasis of pulse-echo method. It was found...By means of ultrasonic attenuation apparatus, the ultrasonic velocity and attenuation ofanhydride-cured epoxy resins (EP)/poly (ethylene oxide) (PEO) blends were measured on thebasis of pulse-echo method. It was found that the sonic velocity of the blends decreased as thetemperature increased, but attenuation coefficient increased and possessed a peak value. Largervelocity and smaller attenuation coefficient(α)can be obtained from perfect crosslinking networkstructures of pure DGEBA cured with phthalic anhydride(PA). As for cured DGEBA/PEO blendsystems,sonic velocity decreased as a function of PEO concentration,but attenuation coefficient(α) increased.展开更多
Background:Applying ultrasonic imaging system during surgery requires the poring of saline,performing the measurement,and acquiring data from its display—which requires time and is highly“performer dependent,”i.e.,...Background:Applying ultrasonic imaging system during surgery requires the poring of saline,performing the measurement,and acquiring data from its display—which requires time and is highly“performer dependent,”i.e.,the measure is of a subjective nature.A new ultrasonic device was recently developed that overcomes most of these drawbacks and was successfully applied during tumor-in-brain neurosurgeries.The purpose of this study was to compare the two types of US devices and demonstrate their properties.Methods:The study was performed in the following stages:(i)an ex vivo experiment,where slices of the muscle and brain of a young porcine were laid one on top the other.Thicknesses and border depths were measured and compared,using the two types of US instruments.(ii)During human clinical neurosurgeries,tumor depth was compared by measuring it with both devices.(iii)Following the success of stages(i)and(ii),using solely the new US device,the tumor thickness was monitored while its resection.Correlation,Pearson’s coefficient,average,mean,and standard deviation were applied for statistical tests.Results:A high correlation was obtained for the distances of tissue borders and for their respective thicknesses.Applying these ultrasonic devices during neurosurgeries,tumor depths were monitored with high similarity(87%),which was also obtained by Pearson’s correlation coefficient(0.44).The new US device,thanks to its small footprint,its remote measurement,and the capability of monitoring intraoperatively and in real-time,provides the approach to tumor’s border before its complete resection.Conclusions:The new US device provides better accuracy than an ultrasonic imaging system;its data is objective;it enables to control the residual tumor thickness during its resection,and it is especially useful in restricted areas.These features were found of great help during a tumor-in-brain surgery and especially in the final stages of tumor’s resection.展开更多
Ultrasonic velocity was measured by an automatic pulse-echo velocimeter at various temperatures in nitric acid at various concentrations ranging from 20 to 99%. The various parameters i.e. molar sound velocity, specif...Ultrasonic velocity was measured by an automatic pulse-echo velocimeter at various temperatures in nitric acid at various concentrations ranging from 20 to 99%. The various parameters i.e. molar sound velocity, specific acoustic impcdance, adiabatic compressibility,intermolecular free length for the solution and the ultrasonic velocity of pure nitric acid were computed from the measurement results. Excess ultrasonic velocity, excess molar volume, excess adiabatic compressibility and excess intermolecular free length, were also calculated. The results show that with increasing concentration of nitric acid the strength of ion-ion interaction in the solution may first increase to a maximum and then decreases.展开更多
文摘In order to meet the high precision requirement of wide steel strip in industry field, a novel online measurement of roller profile based on sonic circulation and pulse-echo technology was introduced. All kinds of the factors influencing the accuracy of roller profile online measurement were analyzed in detail and error compensation analysis of system was accordingly presented. In order to reduce count error, field program gate array(FPGA) was introduced and a highprecision data acquisition system was designed based on digital phase-shift technology. Experiments indicate that the standard deviation of measure data was 7.27 μm, which showed the feasibility and validity of the proposed method, and realized the roll profile measurement with high precision.
文摘By means of ultrasonic attenuation apparatus, the ultrasonic velocity and attenuation ofanhydride-cured epoxy resins (EP)/poly (ethylene oxide) (PEO) blends were measured on thebasis of pulse-echo method. It was found that the sonic velocity of the blends decreased as thetemperature increased, but attenuation coefficient increased and possessed a peak value. Largervelocity and smaller attenuation coefficient(α)can be obtained from perfect crosslinking networkstructures of pure DGEBA cured with phthalic anhydride(PA). As for cured DGEBA/PEO blendsystems,sonic velocity decreased as a function of PEO concentration,but attenuation coefficient(α) increased.
文摘Background:Applying ultrasonic imaging system during surgery requires the poring of saline,performing the measurement,and acquiring data from its display—which requires time and is highly“performer dependent,”i.e.,the measure is of a subjective nature.A new ultrasonic device was recently developed that overcomes most of these drawbacks and was successfully applied during tumor-in-brain neurosurgeries.The purpose of this study was to compare the two types of US devices and demonstrate their properties.Methods:The study was performed in the following stages:(i)an ex vivo experiment,where slices of the muscle and brain of a young porcine were laid one on top the other.Thicknesses and border depths were measured and compared,using the two types of US instruments.(ii)During human clinical neurosurgeries,tumor depth was compared by measuring it with both devices.(iii)Following the success of stages(i)and(ii),using solely the new US device,the tumor thickness was monitored while its resection.Correlation,Pearson’s coefficient,average,mean,and standard deviation were applied for statistical tests.Results:A high correlation was obtained for the distances of tissue borders and for their respective thicknesses.Applying these ultrasonic devices during neurosurgeries,tumor depths were monitored with high similarity(87%),which was also obtained by Pearson’s correlation coefficient(0.44).The new US device,thanks to its small footprint,its remote measurement,and the capability of monitoring intraoperatively and in real-time,provides the approach to tumor’s border before its complete resection.Conclusions:The new US device provides better accuracy than an ultrasonic imaging system;its data is objective;it enables to control the residual tumor thickness during its resection,and it is especially useful in restricted areas.These features were found of great help during a tumor-in-brain surgery and especially in the final stages of tumor’s resection.
文摘Ultrasonic velocity was measured by an automatic pulse-echo velocimeter at various temperatures in nitric acid at various concentrations ranging from 20 to 99%. The various parameters i.e. molar sound velocity, specific acoustic impcdance, adiabatic compressibility,intermolecular free length for the solution and the ultrasonic velocity of pure nitric acid were computed from the measurement results. Excess ultrasonic velocity, excess molar volume, excess adiabatic compressibility and excess intermolecular free length, were also calculated. The results show that with increasing concentration of nitric acid the strength of ion-ion interaction in the solution may first increase to a maximum and then decreases.
