Electroacoustic effects in ultrasonic measurings

Methods of measuring of parameters of ultrasound propagation were investigated with the aim of complex study of the processes of radiation, formation and averaging of acoustic fields by means of real piezotransformers of the pre-arranged geometry with due regard for their electrical load in order to develop the theoretical principles of ultrasonic measurings. As a result new rules of behaviour of the gains of electroacoustic system in quasistationary, interferometric and pulse modes of radiation-reception were detected. The metrologically substantiated recommendations for maximum high accuracy of measuring were elaborated and introduced into practiceAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio

Mandibular reconstruction - review of methods, indications and results

The increasing importance of NDE areas such as quality of material processing, [1,2], fatigue [3,4], and bond strength has expanded the significance of the measurement of the nonlinearity parameter, β. However, to become a useful NDE technique, β measurements must be easily performed in the field. The purpose of this work is to address two techniques that are applicable to field measurements

Long-term prognosis after resection of hepatocellular carcinoma associated with hepatitis B-related cirrhosis

The accurate measurement of ultrasonic attenuation is very important, since it has a great utility in the wide area of materials characterization. In this paper, a new method of measuring the attenuation is presented, which employs electromagnetic acoustic resonance (EMAR) [1–3]. The EMAR is a combination of resonance method and electromagnetic acoustic transducers (EMATs). At a resonance, many reflection echoes are coherently overlapped each other, which serves to provide an easily measurable signal intensity, compensating in excess for the inefficient transduction with EMATs. Use of a noncontacting or weakly coupling EMAT for the attenuation measurement has a pronounced advantage of eliminating the extra energy losses, which otherwise occur with the conventional contacting or immersion tests based on the piezoelectric transducers