Papers

Fiscal year 2020
‘ Yoshikazu Ohara, Hiromichi Nakajima, Sylvain Haupert, Toshihiro Tsuji, Tsuyoshi Mihara, "Imaging of Three-Dimensional Crack Open/Closed Distribution by Nonlinear Ultrasonic Phased Array Based on Fundamental Wave Amplitude Difference", Japanese Journal of Applied Physics, 59 (2020) SKKB01-1-9.
https://doi.org/10.35848/1347-4065/ab79ea

Fiscal year 2019
‘ Marcel Remillieux, Djamel Kaoumi, Yoshikazu Ohara, Marcie Stuber Geesey, Li Xi, Ryan Schoell, Charles Bryan, David Enos, Deborah Summa, T. J. Ulrich, Brian Anderson, Zeev Shayer, "Detecting and Imaging Stress Corrosion Cracking in Stainless Steel, with Application to Inspecting Storage Canisters for Spent Nuclear Fuel", NDT&E International 109 (2020) 102180-1-17.
https://doi.org/10.1016/j.ndteint.2019.102180 
‘ Yoshikazu Ohara, Hiromichi Nakajima, Toshihiro Tsuji, Tsuyoshi Mihara, "Nonlinear Nonlinear Surface-Acoustic-Wave Phased Array with Fixed-Voltage Fundamental Wave Amplitude Difference for Imaging Closed Cracks", NDT&E International 108 (2019) 102170-1-10. 
https://doi.org/10.1016/j.ndteint.2019.102170
‘ Yoshikazu Ohara, Hiromichi Nakajima, Sylvain Haupert, Toshihiro Tsuji, Tsuyoshi Mihara, "Nonlinear Ultrasonic Phased Array with Fixed-Voltage Fundamental Wave Amplitude Difference for High-Selectivity Imaging of Closed Cracks", The Journal of the Acoustical Society of America 146-1 (2019) 266-277. 
https://doi.org/10.1121/1.5116017
‘ Yoshikazu Ohara, Jack Potter, Hiromichi Nakajima, Toshihiro Tsuji, Tsuyoshi Mihara, "Multi-Mode Nonlinear Ultrasonic Phased Array for Imaging Closed Cracks", Japanese Journal of Applied Physics 58 (2019) SGGB06-1-7.
https://doi.org/10.7567/1347-4065/ab0adc 
‘ Sylvain Haupert, Yoshikazu Ohara, Ewen Carcreff, Guillaume Renaud, "Fundamental Wave Amplitude Differene Imaging for Detection and Characterization of Embedded Cracks", Ultrasonics 96 (2019) 132-139.
https://doi.org/10.1016/j.ultras.2019.02.003 

Fiscal year 2018
‘ Yoshikazu Ohara, Jack Potter, Hiromichi Nakajima, Toshihiro Tsuji, Tsuyoshi Mihara, "Multi-Mode Nonlinear Ultrasonic Phased Array for Imaging Closed Cracks", Proceedings of Symposium on Ultrasonic Electronics, 39, 2018, pp.2P2-8-1-2.
‘ Yoshikazu Ohara, Sylvain Haupert, Sinan L, "Ultrafast Phased Array Imaging with Pump Excitation: an Application to Closed Crack Characterization", Proceedings of Symposium on Ultrasonic Electronics, 39, 2018, pp.3P2-10-1-2.
‘ Hiromichi Nakajima, Yoshikazu Ohara, Sylvain Haupert, Toshihiro Tsuji, Tsuyoshi Mihara, "Incident-Wave-Amplitude Dependence of Closed Crack Imaging by Nonlinear Ultrasonic Phased Array with Fized-Voltage Amplitude Subtraction", Proceedings of Symposium on Ultrasonic Electronics, 39, 2018, pp.1P2-14-1-2.
‘ Kosuke Kikuchi, Yoshikazu Ohara, Toshihiro Tsuji, Tsuyoshi Mihara, "Development of Soft PZT Phased Array Transducer for Large Amplitude Incidence", Proceedings of Symposium on Ultrasonic Electronics, 39, 2018, pp.3P2-2-1-2.
‘ Yoshikazu Ohara, Jack Potter, Sylvain Haupert, Hiromichi Nakajima, Toshihioro Tsuji, Tsuyoshi Mihara, "Multi-Mode Nonlinear Ultrasonic Phased Array for Closed Crack Imaging", Proceedings of Meetings on Acoustics (POMA), 34, 2018, pp. 055001-1-5. https://asa.scitation.org/doi/10.1121/2.0000864
‘ Jiang Jin, Jacques Riviere, Yoshikazu Ohara, Parisa Shoukouhi, "Dynamic Acousto-Elastic Response of Single Fatigue Cracks with Different Microstructural Features: An Experimental Investigation", Journal of Applied Physics, 124, 2018, pp.075303-1-14. (Editor's Pick)
https://aip.scitation.org/doi/10.1063/1.5036531

Fiscal year 2017
‘ Yoshikazu Ohara, Kazushi Yamanaka, Sinan Li, Toshihiro Tsuji, Tsuyoshi Mihara, "Imaging of Branched Stress Corrosion Cracks by Subharmonic Phased Array for Crack Evaluation", Proceedings of Symposium on Ultrasonic Electronics, 38, 2017, pp.1P2-12-1-2.
‘ Hiromichi Nakajima,Yoshikazu Ohara, Toshihiro Tsuji, Tsuyoshi Mihara, "Nonlinear Surface-Acoustic-Wave Phased Array with Fixed-Voltage Amplitude Subtraction Method", Proceedings of Symposium on Ultrasonic Electronics, 38, 2017, pp.2E1-5-1-2.
‘ Kosuke Kikuchi, Yoshikazu Ohara, Toshihiro Tsuji, Tsuyoshi Mihara, "Proposal of Low-Frequency Phased Array for Highly Attenuative Materials and Its Fundamental Study for Large Amplitude Incidence", Proceedings of Symposium on Ultrasonic Electronics, 38, 2017, pp.1P2-11-1-2. 
‘ Toshihiro Tsuji, Shingo Akao, Toru Oizumi, Hideyuki Fukushi, Tatsuhiro Okano, Nagisa Satoh, Nobuo Takeda, Yusuke Tsukahara, Kazushi Yamanaka, "Evaluation of Design Parameters of Pipe Systems for Highly Pure Gases by Ball Surface Acoustic Wave Trace Moisture Analyzer", Proceedings of Symposium on Ultrasonic Electronics, 38, 2017, pp.1P2-6-1-2.
‘ Shingo Akao, Tatsuhiro Okano, Toru Oizumi, Hideyuki Fukushi, Nagisa Sato, Nobuo Takeda, Yusuke Tsukahara, Toshihiro Tsuji, Kazushi Yamanaka, "Development of portable Ball SAW Moisture Analyzer by using USB Pulsar", Proceedings of Symposium on Ultrasonic Electronics, 38, 2017, pp.1P2-8-1-2.
‘ Yoshikazu Ohara, Koji Takahashi, Yoshihiro Ino, Kazushi Yamanaka, Toshihiro Tsuji, Tsuyoshi Mihara, "High-Selectivity Imaging of Closed Cracks in a Coarse-Grained Stainless Steel by Nonlinear Ultrasonic Phased Array Method", NDT&E International, 91 (2017) 139-147. http://dx.doi.org/10.1016/j.ndteint.2017.07.007 
‘ Toshihiro Tsuji, Shingo Akao, Toru Oizumi, Nobuo Takeda, Yusuke Tsukahara, Kazushi Yamanaka, "Moisture Adsorption Desorption Characteristics of Stainless Steel Tubing Measured by Ball Surface Acoustic Wave Trace Moisture Analyzer", Japanese Journal of Applied Physics, 56 (2017) 07JC03.  http://dx.doi.org/10.7567/JJAP.56.07JC03
‘ Kazushi Yamanaka, Shingo Akao, Nobuo Takeda, Toshihiro Tsuji, Toru Oizumi, Yusuke Tsukahara, "Simultaneous Measurement of Gas Concentration and Temperature by the Ball Surface Acoustic Wave Sensor", Japanese Journal of Applied Physics, 56 (2017) 07JC04.  http://dx.doi.org/10.7567/JJAP.56.07JC04
‘ Yoshikazu Ohara, Taro Oshiumi, Hiromichi Nakajima, Kazushi Yamanaka, Xiaoyang Wu, Tetsuya Uchimoto, Tsohiyuki Takagi, Toshihiro Tsuji, Tsuyoshi Mihara, "Ultrasonic Phased Array with Surface Acsoutic Wave for Imaging Cracks", AIP Advances, 7 (2017) 065214.  http://dx.doi.org/10.1063/1.4989725

Fiscal year 2016
‘ Kazushi Yamanaka, Shingo Akao, Nobuo Takeda, Toshihiro Tsuji, Toru Oizumi, Yusuke Tsukahara, "Simultaneous Measurement of Gas Concentration and Temperature by the Ball SAW Sensor", Proceedings of Symposium on Ultrasonic Electronics, 37 (2016) 3E2-4-1-2. 
‘ Toshihiro Tsuji, Shingo Akao, Toru Oizumi, Nobuo Takeda, Yusuke Tsukahara, Kazushi Yamanaka, "Moisture Adsorption Desorption Characteristics of Stainless Steel Tubing Measured by Ball Surface Acoustic Wave Trace Moisture Analyzer", Proceedings of Symposium on Ultrasonic Electronics, 37 (2016) 3P2-9-1-2. 
‘ Harumichi Sato, Hisato Ogiso, Naoko Sato, Toru Shimizu, Shizuka Nakano, Yoshikazu Ohara, Kazushi Yamanaka, "Imaging of Laser Excited Surface Acoustic Wave for In-Process Evaluation of 3D Additive Manufacturing (AM) Process", Proceedings of Symposium on Ultrasonic Electronics, 37 (2016) 3E1-5-1-2. 
‘ Koji Takahashi, Koki Ohmachi, Yoshikazu Ohara, Kazushi Yamanaka "Estimation of Saturated Duration in Phased Array Imaging of Closed Cracks by Global Preheating and Local Cooling"AJ. JSNDIA65-10 (2016) 513-520. [in Japanese]

Fiscal year 2015
‘ Yoshikazu Ohara, Koji Takahashi, Yoshihiro Ino, Kazushi Yamanaka, "Nonlinear Ultrasonic Phased Array Imaging of Closed Cracks Using Global Preheating and Local Cooling", AIP Conference Proceedings, 1985 (2015) 080002-1-4.
‘ Yoshikazu Ohara, Koji Takahashi, Yoshihiro Ino, Kazushi Yamanaka, "Imaging of Closed Cracks in Coarse-Grained Materials by Nonlinear Ultrasonic Phased Array", Proceedings of Symposium on Ultrasonic Electronics, 36 (2015) 2P2-7-1-2.
‘ Harumichi Sato, Hisato Ogiso, Naoko Sato, Toru Shimizu, Shizuka Nakano, Yoshikazu Ohara, Kazushi Yamanaka, "Laser Ultrasonic Characterization of Additive Manufacturing Objects Fabricated by Powder Bed Fusion", Proceedings of Symposium on Ultrasonic Electronics, 36 (2015) 3J3-4-1-2.
‘ Ren Koda, Makoto Hamai, Tsuyoshi Mihara, "Enhance Amplitude of Incident Wave by Using Acoustic Matching Wedge for Subharmonic Ultrasound Measurement", Proceedings of Symposium on Ultrasonic Electronics, 36 (2015) 1P2-12-1-2.
‘ Toshihiro Tsuji, Toru Oizumi, Nobuo Takeda, Shingo Akao, Yusuke Tsukahara, Kazushi Yamanaka, "Burst Waveform Undersampling Circuit for Ball Surface Acoustic Wave Sensor", Proceedings of Symposium on Ultrasonic Electronics, 36 (2015) 3P3-6-1-2.
‘ Azusa Sugawara, Kentaro Jinno, Yoshikazu Ohara, Kazushi Yamanaka, "Closed-Crack Imaging and Scattering Behavior Analysis Using Confocal Subharmonic Phased Array", Japanese Journal of Applied Physics, 54 (2015) 07HC08-1-8. 
‘ Akihiro Ouchi, Azusa Sugawara, Yoshikazu Ohara, Kazushi Yamanaka, "Subharmonic Phased Array for Crack Evaluation Using Surface Acoustic Wave" Japanese Journal of Applied Physics, 54 (2015) 07HC05-1-6. 
‘ Toshihiro Tsuji, Toru Oizumi, Nobuo Takeda, Shingo Akao, Yusuke Tsukahara, Kazushi Yamanaka, "Temperature Compensation of Ball Surface Acoustic Wave Sensor by Two-Frequency Measurement Using Undersampling" Japanese Journal of Applied Physics, 54 (2015) 07HC05-1-6. 
‘ Ren Koda, Tsuyoshi Mihara, Katsuhiro Inoue, Goki Konishi, Yoshio Udagawa, "Transmission of Larger Amplitude Ultrasound with SiC Transistor Pulser for Subharmonic Signal Measurements at Closed Cracks", Proceedings of the 2015 ICU International Congress on Ultrasonics, 70 (2015) 528-531.

Review papers

Fiscal year 2015
‘ Tsuyoshi Mihara, "Basics of Phased Array Measurement for the Popularizaation of This Technique", Journal of JSNDI, 65(2) (2016) 56-60. [in Japanese]
‘ Yoshikazu Ohara, "Nonlinear Ultrasonic Imaging Method for Closed Cracks", Journal of the Japan Society of Mechanical Engineers, 119 (2016) 92-93. [in Japanese]
‘ Yoshikazu Ohara, "Nonlinear Ultrasonic Measurement with Low Frequency and High Frequency for Closed Cracks", The Journal of the Acoustical Society of Japan, 71(12) (2015) 682-688. [in Japanese]
‘ Yoshikazu Ohara, Brian Anderson, T. J. Ulrich, Pierre-Yves Le Bas, Paul Johnson, Sylvain Haupert, "Localization of Closed Cracks Using Multi-Mode Nonlinear Resonant Ultrasound Spectroscopy", Journal of JSNDIA64(12) (2015) 571-578. [in Japanese]
‘ Azusa Sugawara, Kentaro Jinno, Yoshikazu Ohara, Kazushi Yamanaka, "•ΒŒϋ‚«—τ‚̍L”ΝˆΝ‰f‘œ‰»‚Μ‚½‚ί‚Μ‹€Ε“_ƒTƒuƒn[ƒ‚ƒjƒbƒN’΄‰Ή”gƒtƒF[ƒYƒhƒAƒŒƒC‚ΜŠJ”­", ’΄‰Ή”gTECHNOA27(2)[3-4] (2015) 50-55. [in Japanese]

Presentations at international conferences

Fiscal year 2015
‘ Yoshikazu Ohara, "Nonlinear Ultrasonic Phased Array Imaging Methods for Closed Cracks", Seminar at Hanyang University, Korea.(Invited)
‘ Yoshikazu Ohara, "Nonlinear Ultrasonic Phased Array Imaging Methods for Closed Cracks", Seminar at Seoul National University of Science & Technology (Seoul Tech), Korea.(Invited)
‘ Yoshikazu Ohara, Koji Takahashi, Yoshihiro Ino, Kazushi Yamanaka, Tsuyoshi Mihara, "Imaging of Closed Cracks in Coarse-Grained Materials by Nonlinear Ultrasonic Phased Array", The 35th Symposium on Ultrasonic Electronics (USE2015), Epochal Tsukuba International Congress Center, Tsukuba, Japan
‘ Ren Koda, Makoto Hamai, Tsuyoshi Mihara, "Enhance Amplitude of Incident Wave by Using Acoustic Matching Wedge for Subharmonic Ultrasound Measurement", The 35th Symposium on Ultrasonic Electronics (USE2015), Epochal Tsukuba International Congress Center, Tsukuba, Japan
‘ Toshihiro Tsuji, Toru Oizumi, Nobuo Takeda, Shingo Akao, Yusuke Tsukahara, Kazushi Yamanaka, "Burst Waveform Undersampling Circuit for Ball Surface Acoustic Wave Sensor", The 35th Symposium on Ultrasonic Electronics (USE2015), Epochal Tsukuba International Congress Center, Tsukuba, Japan
‘ Harumichi Sato, Hisato Ogiso, Naoko Sato, Toru Shimizu, Shizuka Nakano, Yoshikazu Ohara, Kazushi Yamanaka, "Laser Ultrasonic Characterization of Additive Manufacturing Objects Fabricated by Powder Bed Fusion", The 35th Symposium on Ultrasonic Electronics (USE2015), Epochal Tsukuba International Congress Center, Tsukuba, Japan
‘ Shingo Akao, Toru Oizumi, Nobuo Takeda, Yusuke Tsukahara, Toshihiro Tsuji, Kazushi Yamanaka, "Development of Compact, Fast, and Sensitive ball SAW Trace Moisture Sensor Usinng Amorphous SiOx film", The 35th Symposium on Ultrasonic Electronics (USE2015), Epochal Tsukuba International Congress Center, Tsukuba, Japan
‘ Toshihiro Tsuji, Toru Oizumi, Nobuo Takeda, Shingo Akao, Yusuke Tsukahara, Kazushi Yamanaka, "Development of Practical Ball Surface Acoustic Wave Trace Moisture Analyzer by Underssampling", 2015 IEEE International Ultrasonics Symposium, Taipei, Taiwan.
‘ Yoshikazu Ohara, Koji Takahashi, Yoshihiro Ino, Kazushi Yamanaka, Tsuyoshi Mihara, "High-Selectivity Ultrasonic Phased Array Imaging of Closed Cracks in Coarse-Grained Materials Using Global Preheating and Local Cooling", JSNDI Fall Conference, Hokkaido
‘ Yoshikazu Ohara, Koji Takahashi, Yoshihiro Ino, Kazushi Yamanaka, "Nonlinear Ultrasonic Imaging of Closed Cracks in a Coarse Grained Stainless Steel by Global Preheating and Local Cooling", The 42nd Annual Review of Progress in Quantitative Nondestructive Evaluation (QNDE), Minneapolis, Minnesota, America.
‘ Yoshikazu Ohara, Akihiro Ouchi, Juri Saito, Kazushi Yamanaka, "Crack Length Measurements by Subharmonic Phased Array for Crack Evaluation with Surface Acoustic Wave with Water Immersion", The 42nd Annual Review of Progress in Quantitative Nondestructive Evaluation (QNDE), Minneapolis, Minnesota, America.
‘ Ren Koda, Tsuyoshi Mihara, Yoshio Udagawa, "Development of Ultrasonic Pulser for Large Displacement Wave Generation Using Soft PZT Element Transducer", The 42nd Annual Review of Progress in Quantitative Nondestructive Evaluation (QNDE), Minneapolis, Minnesota, America.
‘ Yoshikazu Ohara, "Ultrasonic Phased Array Imaging of Closed Cracks Using Global Preheating and Local Cooling (GPLC)", Seminar at Laboratoire d'Imagerie Parametrique, UPMC(Universite Pierre et Marie Curie), Paris 6th, Paris, France.
‘ Yoshikazu Ohara, Koji Takahashi, Yoshihiro Ino, Kazushi Yamanaka, "Closed-Crack Imaging by Nonlinear Ultrasonic Phased Array with Global Preheating and Local Cooling (GPLC)", The 20th International Conference on Nonlinear Elasticity in Materials (ICNEM), Bruges, Belgium.
‘ Yoshikazu Ohara, Akihiro Ouchi, Juri Saito, Kazushi Yamanaka, "Measurement of Crack Length Using Subharmonic Phased Array for Crack Evaluation with Surface Acoustic Wave (SAW SPACE)", The 20th International Conference on Nonlinear Elasticity in Materials (ICNEM), Bruges, Belgium.
‘ Yoshikazu Ohara, Koji Takahashi, Yoshihiro Ino, Kazushi Yamanaka, "Nonlinear Ultrasonic Phased Array Imaging of Closed Crack Using Global Preheating and Local Cooling", 20th International Symposium on Nonlinear Acoustics (ISNA), Lyon, France.

Awards

‘currently under construction

Thesis

‘currently under construction