Speech broadcasting via loudspeakers is widely used in public transportation to send broadcast notifications. However, listeners often fail to catch spoken context from speech broadcasts due to excessive environmental noise. We propose an ultrasonic communication method that can be applied to loudspeakerbased speech broadcasting to cope with this issue. In other words, text notifications are mo...

A new modeling and classification method of ultrasonic signals based on empirical mode decomposition(EMD) and neural network is put forward in the paper. Firstly, the original ultrasonic flaw signals are decomposed into a finite number of stationary intrinsic mode functions (IMFs) by EMD, and the Fourier transformation of IMF is made. The next step is to find a set of classification values from...

This paper reports the preliminary results of a newly developed method for measuring dynamic modulus of thermoplastic materials at a given ultrasonic frequency. In the method, a material specimen is squeezed at the tip of the horn of a conventional ultrasonic welding machine. The mechanical impedance of the material specimen under loading is then deduced by processing the input electrical imped...

The study of asymmetrical patterns of the light diffracted by ultrasonic waves has been utilized in the last decades to investigate ultrasonic wave distortions caused by the nonlinearity of the medium. In contrast to the investigation of diffraction patterns in space, a novel optical method is proposed in this work to analyze, in the frequency domain, the phase modulation (related to the Raman-...

The application of laser ultrasonic technique is developed for evaluation of friction stir spot welding (FSSW) quality. The features of laser-generated ultrasonic waves in good welding and incomplete fusion area are simulated by finite element method (FEM). The non-contact laser ultrasonic inspection system (LUIS) was established to verify the numerical results. The interaction of laser ultraso...

Ultrasound energy liquefies high fluid content tissues, such as epidermis and sweat glands via cavitation, but minimally affects dermis, blood vessels, and nerves at the same energy level. We have used ultrasonic surgical aspirator to treat several skin diseases such as Bowen’s disease, wart, prurigo nodularis, and osmidrosis. The ultrasonic surgical aspirator offers an effective and safe metho...

Currently there is no reliable objective method to quantify the setting properties of acrylic bone cements within an operating theatre environment. Ultrasonic technology can be used to determine the acoustic properties of the polymerising bone cement, which are linked to material properties and provide indications of the physical and chemical changes occurring within the cement. The focus of th...

Background:  Some studies show that frozen shoulder is due to the pathologic changes in the muscles around the shoulder. Measurement of the ultrasonic thickness of a muscle is a method for measuring the muscle changes. There is no study about the reliability of measurement of the muscle’s ultrasonic thickness around the shoulder in patients with frozen shoulder. The present study aims to invest...

Because of the need of rapid detection of internal defects and embedded object in concrete structures, a ultrasonic detecting method with linear array transducers is presented here, which is the high-resolution and efficient imaging technique for concrete materials by combining with synthetic aperture focusing technique (SAFT). At first, simulation data of array detection are processed to be am...

8.1 Historical Background 8.2 Theory of Wave Propagation 8.3 Pulse Velocity Test Instrument 8.4 The Pulse Velocity Method 8.5 Factors Affecting Pulse Velocity Effects of Concrete Properties • Other Effects • Temperature of Concrete 8.6 Standardization of the Pulse Velocity Method 8.7 Applications Estimation of Strength of Concrete • Establishing Homogeneity of Concrete • Studies on the Hydratio...