Small vibrations are simultaneously measured at two adjacent points on the aortic wall near the aortic valve by electronically alternating the directions of the ultrasonic beam. The transit delay time of the pulse wave between these two points is determined from two vibration signals obtained by this alternation beam method. The local pulse wave velocity at several millimeters on the aorta is p...

Finite element method (FEM) has been employed extensively for vibration modal analysis of piezoelectric transducers and devices. In recent years, there has been a growing interest in the simulation and analysis of piezoelectric transducers by using equivalent electrical circuit models. This paper has been devoted to such approach for two designed and fabricated ultrasonic sandwich transducers h...

INTRODUCTION Type I laryngoplasty has become the most dependable procedure for the management of anterior and midglottic incompetence since its classification by Isshiki in 1974. Many procedure variations have emerged, including the development of numerous techniques, implants, and prefabricated systems increasing the utilization of medialization laryngoplasty. Sharp dissection of the cartilage...

ABSTRACT Stearic acid was encapsulated successfully with SiO2 shell in nanoscale by situ emulsion interfacial hydrolysis and poly-condensation techniques. The influence of using different mixing techniques on these investigated. Morphologic, thermal crystal structure analysis results show that the ultrasonic technique is suggested for synthesis nanocapsules. Ultrasonic vibrations lead to more h...

By utilizing ultrasonic annealing at a temperature below (or near) the glass transition temperature Tg, we revealed a microstructural pattern of a partially crystallized Pd-based metallic glass with a high-resolution electron microscopy. On the basis of the observed microstructure, we inferred a plausible microstructural model of fragile metallic glasses composed of strongly bonded regions surr...

In this study, constraint groove pressing (CGP) process and ultrasonic assisted CGP (UCGP) process were investigated on the process forces, mechanical properties of the sheet, including hardness and tensile tests and grain size. Pure copper sheets were used as samples in this research. Samples were tested both with and without ultrasonic vibrations for mechanical properties and grain size up to...

Friction and wear are detrimental to engineered systems. Ultrasonic lubrication is achieved when the interface between two sliding surfaces is vibrated at a frequency above the acoustic range (20 kHz). As a solid-state technology, ultrasonic lubrication can be used where conventional lubricants are unfeasible or undesirable. Further, ultrasonic lubrication allows for electrical modulation of th...

Ultrasonic energy is widely used in wire bonding for microelectronics packaging. It is necessary to ensure that the maximum ultrasonic vibration displacement occurs at or near the tip of the bonding tool (capillary) for optimal performance. In this study, amplitude profiles of ultrasonic vibrations along capillaries were measured with load using a laser interferometer. This provided valuable in...