Publications by authors named "H Achdjian"

In this work, a flush ultrasonic probe has been developed for the measurement of the velocity and the angle of attack (AOA) of an aircraft. The probe is made of one emitting transducer located at the center of a rotating stage and several receiving transducers located downstream, all transducers radiating in a normal direction perpendicular to the airflow. The determination of speed and AOA are deduced from the time of flight measurement of an ultrasonic wave between the emitter and the receivers propagating in the boundary layer.

View Article and Find Full Text PDF

A statistical model is proposed to relate the scattering properties of a local heterogeneity in a plate to the statistical properties of scattered and reverberated flexural waves. The contribution of the heterogeneity is isolated through the computation of differential signals consisting of a subtraction of the signals recorded after and before introduction of the heterogeneity. The theoretical expression of the average reverberation envelope of these differential signals is obtained as a function of the scattering cross-section of the heterogeneity.

View Article and Find Full Text PDF

We present a 24-year-old combat veteran who underwent extensive work-up for elevated aminotransferases, including liver biopsy, with no underlying pathology identified. Subsequent investigations showed elevated creatinine kinase and aldolase. The patient was later diagnosed with biopsy-proven dysferlin-deficient muscular dystrophy.

View Article and Find Full Text PDF