Acoustic CT System for Temperature Distribution and Wind Velocity Vector Measurement
In this report, a measurement method for cross-sectional temperature and wind velocity distribution is discussed. A novel method based on an acoustic CT technique is proposed. Specifically, the temperature and the wind velocity distributions are estimated simultaneously using the time of flight data of several ultrasonic propagation paths. The temperature and the wind velocity effects can be distinguished by considering sum and difference of the time of flight (TOF) data. Two types of projection data, temperature-oriented data and wind-velocity-oriented data, components are obtained. A filtered back projection method and inverse matrix method are applied to reconstruct the temperature and the wind velocity distributions, respectively. An experimental system is designed and fabricated to realize simultaneous temperature and wind velocity distribution measurements. Through this system, the effectiveness of the proposed measurement method is confirmed.
Ultrasonic tomographic imaging of solid objects in air using an array of fan-shaped-beam electrostatic transducers
A technique capable of imaging solid object distributions in air is presented. The imaging technique is based on a tomographic method, similar in concept to those used in diagnostic computerised tomography. The reconstruction algorithm has been implemented in a software modelling package to allow the performance of the technique to be evaluated for various object distributions and array configurations. Furthermore, fan-shaped-beam (FSB) electrostatic transducers have been developed to allow experimental evaluation of the technique. Experimental and simulated results indicate the utility of the approach to provide information on the size, shape, location and orientation of solid objects.
Comparative study of the molecular species of chloropropanediol diesters and triacylglycerols in milk fat
In an effort to establish the origin of the fatty acid esters of 3-chloropropanediol, which recently have been isolated in small amounts from goat milk, we compared the molecular species composition of the chlorohydrin diesters and of goat milk triacylglycerols. The chloropropanediol diesters were found to be composed of molecular species containing C10−C18 fatty acids and corresponded closely in carbon number to those calculated for the long chain sn-1,2-diacyl-glycerol moieties of goat milk triacylglycerols. The molecular species of goat milk total triacylglycerols contained C4−C18 fatty acids. It is suggested that triacylglycerols and chloropropanediol diesters are derived from the same pool of long chain fatty acids. A molecular distillate of bovine milk fat did not contain chloropropanediol diesters, while the available samples of human milk fat were shown to contain alkyldiacylglycerols as the major components of a neutral lipid fraction corresponding in polarity to the chloropropanediol diesters.