This paper proposes new method for object reference which enables a person to find surrounding objects and develops a navigation system named CoCo. CoCo employs an ultrasonic directional speaker with a rotating base. Ultrasonic wave transmitted by an ultrasonic directional speaker is converted to audible sound when it reflects on floor, wall, or object. Based on this property, CoCo can emit aud...

The electroma.gnetic, noncontact transducer (EMAT) is particularly well suited to ultrasonic inspec~ tion problems where it is difficult or impossible to couple the sound into the object being tested ~ through a liquid or grease layer. For inspecting buried natural gas pipelines, the inspection process must be carried out by a self contained instrument package blown through the pipe by the gas ...

Ultrasonic distance measurement using the pulse-echo method is based on the determination of the time of flight of ultrasonic waves. The pulse-compression technique, in which the cross-correlation function of a detected ultrasonic wave and a transmitted ultrasonic wave is obtained, is the conventional method used for improving the resolution of distance measurement. However, the calculation of ...

Air – coupled ultrasonic investigation possess a great potential for investigation of aerospace composite materials, because it avoids disadvantages caused by immersion or contact techniques. In the work the test sample of the GLARE3-3/2 composite material with artificial delamination type defect was investigated. Numerical and experimental investigations using focussed air – coupled ultrasonic...

A digitally controlled drive system was implemented in this study to control the speed and direction of a travelling-wave ultrasonic motor. The drive system, based on a 2-phase voltage-fed high-frequency serial-resonant inverter, uses the mechanical resonant frequency of an ultrasonic motor. A TMS320F243 digital signal processor was used to control an ultrasonic motor drive system. The speed co...

This paper addresses in-situ stress-estimation methods based on the Kaiser effect. The physical and mechanical properties of granite, diorite, granodiorite samples selected at different depth intervals core obtained from a wellbore were examined. ultimate uniaxial compressive strength, modulus elasticity, Poisson’s ratio rock determined using presses strain gauges. Also, local longitudinal shea...

Ultrasonic compression wave propagation is sensitive to the physical state of particulate liquid suspensions – colloids and emulsions. It is possible to estimate dispersed particle size distribution (PSD) from measurements of wave attenuation and/or phase velocity as functions of frequency. It is also possible to detect and characterise dynamic phenomena such as flocculation, network formation ...

A double ultrasonic source has been shown to dramatically increase dispersion efficiency of carbon nanotubes. Thermal measurements of dispersing fluid only show temperature rises commensurate with the power levels of the two ultrasonic sources; which is validated by predictions of statistical energy analysis (SEA) based on wave superposition principles. In this paper, nonlinear wave resonance c...

Currently, vehicles are often equipped with active safety systems to reduce the risk of accidents, many of which occur in the urban environments. The most popular include Antilock Braking Systems (ABS), Traction Control and Stability Control. All these systems employ different types of sensors to constantly monitor the conditions of the vehicle, and respond in an emergency situation. In this pa...

In part 21 of the tutorial series "Acoustofluidics--exploiting ultrasonic standing wave forces and acoustic streaming in microfluidic systems for cell and particle manipulation", we review applications of ultrasonic standing waves used for enhancing immunoassays and particle sensors. The paper covers ultrasonic enhancement of bead-based immuno-agglutination assays, bead-based immuno-fluorescenc...