IMAGING FLAWS CLOSE TO SURFACE USING FOCUSED SURFACE ACOUSTIC-WAVES

Response of acoustic imaging systems using convergent leaky waves to cylindrical flaws Günalp, Nilgün; Atalar, Abdullah (Institute of Electrical and Electronics Engineers (IEEE), 1989-9) A theoretical study of imaging systems utilizing focused leaky surface acoustic waves (SAWs), and their response to certain kind of defects is presented. In particular, circular cylindrical inhomogeneities with axes perpendicular to the surface are considered. The scattering of the SAW from this cylinder is formulated with some approximations. The surface wave incident on the inhomogeneity is initially found as an angular spectrum of plane waves. However, to apply the boundary conditions at the cylindrical ...
Near-field scanning in the time domain on a spherical surface - A formulation using the free-space Green's function Koc, S; Aydın Çivi, Hatice Özlem; Buyukdura, OM (2001-10-01) Two formulations for determining the characteristics of an unknown source of acoustic waves using the measurement of its field at its near zone are presented. The measurement in both cases is to be performed on a spherical scan surface which encapsulates the source. The first is for an ideal probe which measures the field at its location. The knowledge of the field is sufficient; its normal derivative is not required. In the second formulation a realistic probe is considered. This time it is required only t...
Design and implementation of an annular acoustic levitation system Kandemir, Mehmet Hakan; Çalışkan, Mehmet; Department of Mechanical Engineering (2014) In standing wave acoustic levitation technique, a standing wave is obtained between a source and a reflector. Particles can be attracted towards pressure nodes in standing waves owing to the spring action. Hence, particles can be suspended in air. This operation can be performed on continuous structures as well as in several numbers of axes. In this study an annular acoustic levitation set-up is designed and built. The set-up consists of two langevin type piezoelectric transducers, two waveguides, an annula...
Classification of Almost Completely Decomposable Groups Solak, Ebru(2018-12-31) Almost completely decomposable (acd) gruplar torsiyonsuz degismeli gruplardır. Bu nedenle acd grupları sonlu boyutlu Q-vektör uzaylarının toplamsal alt grupları olarak düşünebiliriz.Acd gruplarla ile ilgili hesaplamalar zor olduğundan çalışması ve sınıflandırması zordur. Bu grupların ayrışımı ve sınıflandırması ile ilgili ilk çalışmalar L.Lady tarafından 1970’li yıllarda yapılmıştır. Hemen hemen ayrışan (acd) gruplar torsiyonsuz değişmeli gruplar teorisinin önemli bir araştırma koludur. Hemen hemen ayrışan ...
Evaluation of the perceived naturalness of artificial reverberation algorithms Djordjevic, Stojan; Hacıhabiboğlu, Hüseyin; Cvetkovic, Zoran; De Sena, Enzo (null; 2020-01-01) © 2020 148th Audio Engineering Society International Convention. All rights reserved.Listening tests were carried out using a modified MUSHRA method to compare the perceived naturalness of reverberation generated using scattering delay networks (SDNs), feedback delay networks (FDNs), CATT-Acoustic modelling, and convolution with recorded room impulse responses. The difference in naturalness ratings achieved by reverberation generated using FDNs and SDNs was statistically significant, with the mean rating be...

Citation Formats

H. KOYMEN, A. ATALAR, T. CILOGLU, M. ONDER, C. UZEL, and H. YAVUZ, “IMAGING FLAWS CLOSE TO SURFACE USING FOCUSED SURFACE ACOUSTIC-WAVES,” 1987, vol. 34, p. 399, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/68351.