scholarly journals Transmission Sensitivities of Contact Ultrasonic Transducers and Their Applications

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4396
Author(s):  
Kanji Ono ◽  
Hideo Cho ◽  
Hartmut Vallen ◽  
Robert T. M’Closkey
Keyword(s):  
Acoustic Emission ◽  
System Development ◽  
Ultrasonic Transducers ◽  
Interfacial Wave ◽  
Actual Usage ◽  
Material Evaluation ◽  
Loading Effects ◽  
Acoustic Emission Sensors ◽  
Multiple Sensing

In all ultrasonic material evaluation methods, transducers and sensors play a key role of mechanoelectrical conversion. Their transduction characteristics must be known quantitatively in designing and implementing suc+cessful structural health monitoring (SHM) systems. Yet, their calibration and verification have lagged behind most other aspects of SHM system development. This study aims to extend recent advances in quantifying the transmission and receiving sensitivities to normally incident longitudinal waves of ultrasonic transducers and acoustic emission sensors. This paper covers extending the range of detection to lower frequencies, expanding to areal and multiple sensing methods and examining transducer loading effects. Using the refined transmission characteristics, the receiving sensitivities of transducers and sensors were reexamined under the conditions representing their actual usage. Results confirm that the interfacial wave transmission is governed by wave propagation theory and that the receiving sensitivity of resonant acoustic emission sensors peaks at antiresonance.

scholarly journals Rayleigh Wave Calibration of Acoustic Emission Sensors and Ultrasonic Transducers

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3129 ◽  
Author(s):  
Kanji Ono
Keyword(s):  
Acoustic Emission ◽  
Rayleigh Waves ◽  
Guided Waves ◽  
Laser Interferometer ◽  
Ultrasonic Transducers ◽  
Glass Capillary ◽  
Small Aperture ◽  
Transfer Block ◽  
Acoustic Emission Sensors ◽  
Incident Waves

Acoustic emission (AE) sensors and ultrasonic transducers were characterized for the detection of Rayleigh waves (RW). Small aperture reference sensors were characterized first using the fracture of glass capillary tubes in combination with a theoretical displacement calculation, which utilized finite element method (FEM) and was verified by laser interferometer. For the calibration of 18 commercial sensors and two piezoceramic disks, a 90° angle beam transducer was used to generate RW pulses on an aluminum transfer block. By a substitution method, RW receiving sensitivity of a sensor under test was determined over the range of frequency from 22 kHz to 2 MHz. Results were compared to the sensitivities to normally incident waves (NW) and to other guided waves (GW). It was found that (1) NW sensitivities are always higher than RW sensitivities, (2) differences between NW and RW receiving sensitivities are dependent on frequency and sensor size, (3) most sensors show comparable RW and GW receiving sensitivities, especially those of commonly used AE sensors, and (4) the receiving sensitivities of small aperture (1 mm diameter) sensors behave differently from larger sensors.

Acoustic Emission Sensors using Silicon Mechanical Resonators

2015 ◽  
Vol 135 (12) ◽  
pp. 484-489
Author(s):  
Kengo Takata ◽  
Takashi Sasaki ◽  
Mitsutomo Nishizawa ◽  
Hiroshi Saito ◽  
Shinsuke Yamazaki ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Mechanical Resonators ◽  
Acoustic Emission Sensors

scholarly journals Application of Fiber Bragg Grating Acoustic Emission Sensors in Thin Polymer-Bonded Explosives

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3778 ◽  
Author(s):  
Tao Fu ◽  
Peng Wei ◽  
Xiaole Han ◽  
Qingbo Liu
Keyword(s):  
Acoustic Emission ◽  
Fiber Bragg Grating ◽  
Bragg Grating ◽  
Location Method ◽  
Thin Polymer ◽  
Time Coefficient ◽  
Polymer Bonded Explosives ◽  
Acoustic Emission Sensors

Fiber Bragg grating (FBG) acoustic emission (AE) sensors have been used in many applications. In this paper, based on an FBG AE sensor, the sensing principle of the interaction between the AE wave and the sensor is introduced. Then, the directionality of the FBG AE sensor on the surface of a thin polymer-bonded explosive (PBX) material is studied. Finally, the time coefficient location method is proposed to correct the AE time detected by the FBG AE sensor, thereby improving the accuracy of location experiments.

scholarly journals English for European Communication and Tourism: Focus on Pragmatic Competence

2019 ◽  
Vol 17 (3) ◽  
pp. 317-332
Author(s):  
Agata Klimczak-Pawlak
Keyword(s):  
Cross Cultural ◽  
Data Driven ◽  
Pragmatic Competence ◽  
The European Union ◽  
Cultural Perspective ◽  
Language Background ◽  
Actual Usage ◽  
Successful Communication ◽  
Data Driven Approach

Pragmatic competence in L2 English is claimed here to be crucial for successful communication in a variety of communicative contexts across Europe. However, due to language background, cultural and identity differences among users of English, there is a need for reflection and data-driven examination of how the language is used in specific situations. This paper adopts a cross-cultural perspective on the study of the use of English in the European Union with focus on its role in tourism. The role of English as the language of communication in Europe is discussed, followed by a proposal as to the way in which its actual usage can be studied. The data-driven approach to pragmatic behavior is advocated as the basis for the development of pragmatic competence in learners of English with focus on those who wish to engage in tourism.

scholarly journals Crack detection in riveted lap joints using fiber laser acoustic emission sensors

2017 ◽  
Vol 25 (16) ◽  
pp. 19457 ◽  
Author(s):  
G. A. Cranch ◽  
L. Johnson ◽  
M. Algren ◽  
S. Heerschap ◽  
G. A. Miller ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Fiber Laser ◽  
Crack Detection ◽  
Lap Joints ◽  
Acoustic Emission Sensors ◽  
Riveted Lap Joints

Piezoelectric MEMS acoustic emission sensors

2018 ◽  
Vol 279 ◽  
pp. 53-64 ◽  
Author(s):  
Minoo Kabir ◽  
Hanie Kazari ◽  
Didem Ozevin
Keyword(s):  
Acoustic Emission ◽  
Acoustic Emission Sensors ◽  
Piezoelectric Mems

Spalt modifies EGFR-mediated induction of chordotonal precursors in the embryonic PNS of Drosophila promoting the development of oenocytes

Development ◽  
2001 ◽  
Vol 128 (5) ◽  
pp. 711-722 ◽  
Author(s):  
T.E. Rusten ◽  
R. Cantera ◽  
J. Urban ◽  
G. Technau ◽  
F.C. Kafatos ◽  
...  
Keyword(s):  
Nervous System ◽  
Cell Fate ◽  
System Development ◽  
Cell Types ◽  
Nervous System Development ◽  
Dual Function ◽  
Evolutionarily Conserved ◽  
A Cell ◽  
And Migration

Genes of the spalt family encode nuclear zinc finger proteins. In Drosophila melanogaster, they are necessary for the establishment of head/trunk identity, correct tracheal migration and patterning of the wing imaginal disc. Spalt proteins display a predominant pattern of expression in the nervous system, not only in Drosophila but also in species of fish, mouse, frog and human, suggesting an evolutionarily conserved role for these proteins in nervous system development. Here we show that Spalt works as a cell fate switch between two EGFR-induced cell types, the oenocytes and the precursors of the pentascolopodial organ in the embryonic peripheral nervous system. We show that removal of spalt increases the number of scolopodia, as a result of extra secondary recruitment of precursor cells at the expense of the oenocytes. In addition, the absence of spalt causes defects in the normal migration of the pentascolopodial organ. The dual function of spalt in the development of this organ, recruitment of precursors and migration, is reminiscent of its role in tracheal formation and of the role of a spalt homologue, sem-4, in the Caenorhabditis elegans nervous system.

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