2002 IEEE Ultrasonics Symposium, 2002. Proceedings.最新文献_第2页

Linear array transducers for vibro-acoustography 用于振动声学的线性阵列换能器

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-12-01 DOI: 10.1109/ULTSYM.2002.1193481

G.T. Silva, F. Mostafa

引用次数: 6

Straight crested wave analysis of quartz MEMS ring electroded mesa resonators 石英MEMS环电极台面谐振器的直峰波分析

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-12-01 DOI: 10.1109/ULTSYM.2002.1193564

Y. Yong, J. Vig, A. Ballato

{"title":"Straight crested wave analysis of quartz MEMS ring electroded mesa resonators","authors":"Y. Yong, J. Vig, A. Ballato","doi":"10.1109/ULTSYM.2002.1193564","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193564","url":null,"abstract":"An analytical technique for designing high Q, thickness shear micro electromechanical, ring electroded mesa quartz resonators is proposed. The method is demonstrated using two-dimensional straight crested wave analysis. The design method is based on the two characteristics of a stable resonator: (a) The mode is energy trapped and relatively isolated from its supports, and (b) the motional impedance of the mode is low. The root mean squares of vibration displacements are employed to characterize the modes of vibration, and the thickness shear mode has a large rms u/sub 1/ displacement in the x/sub 1/ direction (diagonal axis). The rms displacement is used to compare the energy trapping of the thickness shear mode as a function of the electrode and plate geometry. For each mode of vibration, the electric flux density D/sub 2/ is calculated at the quartz to electrode interface to yield the electric current at the electrodes. Given a constant driving voltage, the magnitude of the electric current is inversely proportional to the motional impedance. Hence the electric current for a mode as a function of the electrode and plate geometry is employed as a further means for comparing the merits of different resonator designs. Results are shown for a 1 GHz inverted mesa AT-cut resonator.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129161424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

Flow rate measurement using ultrasonic Doppler method with cavitation bubbles 超声多普勒空化气泡法测量流量

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-12-01 DOI: 10.1109/ULTSYM.2002.1193458

Y. Koike, T. Tsuyoshi, H. Kikura, M. Aritomi, M. Mori

引用次数: 7

Numerical evaluation of ultrasonic pulse-echo subwavelength defect detection 超声脉冲回波亚波长缺陷检测的数值评价

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-12-01 DOI: 10.1109/ULTSYM.2002.1193504

Xiangtao Yin, S. A. Morris, W. O’Brien

{"title":"Numerical evaluation of ultrasonic pulse-echo subwavelength defect detection","authors":"Xiangtao Yin, S. A. Morris, W. O’Brien","doi":"10.1109/ULTSYM.2002.1193504","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193504","url":null,"abstract":"The ultrasonic pulse-echo Backscattered Amplitude Integral (BAI)-mode imaging technique [UFFC Trans, 45:30, 1998] has been developed to detect small channel defects in flexible food package seals. This technique detects 38-/spl mu/m-diameter channels reliably and 6-/spl mu/m-diameter channels occasionally using a 17.3-MHz focused transducer in water (20/spl deg/C, /spl lambda/ /spl ap/ 86 /spl mu/m, total sample thickness 22 /spl mu/m). However, interaction between ultrasound and sample microstructure - the underlying detection mechanism is poorly understood. Experimental evidence showed at the subwavelength channel was fused inside the two binding trilaminate plastic package films. Each trilaminate film a three sublayers. Package sample impedance profiles along the ultrasound beam axis were examined. Although identical in nominal impedance properties before sealing, the two binding films showed an asymmetric impedance profile after sealing. A generalized impedance profile model was proposed. The defect detection behavior of the echo signal was investigated by solving the 2D linear acoustic wave equations in fluid with finite-difference time-domain method and the perfectly matched layer absorbing boundary. The normalized correlation coefficients between the simulated and the measured RF echo waveforms were greater than 95% for this generalized model.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128412676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Finite difference modeling of acoustic devices 声学器件的有限差分建模

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1192511

R. A. Pastore, J. Kosinski, Fort Monmouth

引用次数: 0

Micromachined capacitive transducers with improved optical detection for ultrasound applications in air 改进光学检测的微机械电容式换能器在空气中的超声波应用

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1192470

N. Hall, W. Lee, J. Dervan, F. Degertekin

引用次数: 11

Wireless temperature sensor using SAW resonators for immersed and biological applications 无线温度传感器使用SAW谐振器，用于浸入式和生物应用

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193438

S. Ballandras, W. Daniau, G. Martin, P. Berthelot

引用次数: 11

Side radiation of Rayleigh waves from synchronous leaky SAW resonators 同步漏声表面波谐振器瑞利波的侧辐射

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193358

T. Makkonen, M. Kalo, V. Plessky, J. Knuuttila, W. Steichen, A.A. Saloma

{"title":"Side radiation of Rayleigh waves from synchronous leaky SAW resonators","authors":"T. Makkonen, M. Kalo, V. Plessky, J. Knuuttila, W. Steichen, A.A. Saloma","doi":"10.1109/ULTSYM.2002.1193358","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1193358","url":null,"abstract":"Scanning laser probing of leaky wave synchronous resonators used in \"ladder\" SAW filters fabricated on lithium tantalate often reveals the presence of distinct acoustic beams radiated outside the resonator from the transducer region. One of the beams is radiated in the direction perpendicular to the resonator, i.e., parallel to the transducer fingers, while two others are directed obliquely, and symmetrically with respect to the first beam, at an angle of about 60 degrees. We suppose that this radiation is generated by the charges accumulating at the tips of the electrodes. Since the velocity of the \"leaky SAW\" is visibly higher than that of a Rayleigh wave, the synchronism conditions can be met and the periodic system of sources (oscillating charges at the fingertips) generates the beams in the perpendicular direction, as well as the /spl plusmn/1st\" diffraction orders resulting in the two obliquely propagating beams. The coupling strength and slowness of the Rayleigh SAW on 36/spl deg/ and 42/spl deg/ cut LiTaO/sub 3/ substrates vs. propagation direction is computed using 3D Green's function theory and the propagation angles for the Rayleigh wave beams as a function of frequency are predicted. The computed angles compare well with experiments.","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120941254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Diffraction-free propagation of collimated SAW around a quartz ball 石英球周围准直SAW的无衍射传播

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1193350

N. Nakaso, Y. Tsukahara, S. Ishikawa, K. Yamanaka

引用次数: 6

Comparison of ultrasound scattering behavior of Optison/sup /spl reg// and a liquid perfluorocarbon nanoparticle contrast agent option /sup /spl reg//与液体全氟碳纳米颗粒造影剂超声散射行为的比较

2002 IEEE Ultrasonics Symposium, 2002. Proceedings. Pub Date : 2002-10-08 DOI: 10.1109/ULTSYM.2002.1192685

M. Hughes, J. Marsh, A. Woodson, R.W. Fuhrhop, G. M. Lanza, S. Wickline

{"title":"Comparison of ultrasound scattering behavior of Optison/sup /spl reg// and a liquid perfluorocarbon nanoparticle contrast agent","authors":"M. Hughes, J. Marsh, A. Woodson, R.W. Fuhrhop, G. M. Lanza, S. Wickline","doi":"10.1109/ULTSYM.2002.1192685","DOIUrl":"https://doi.org/10.1109/ULTSYM.2002.1192685","url":null,"abstract":"Previously we reported that useful ultrasound contrast enhancement could be obtained using a liquid emulsion contrast agent developed in our laboratory. Although the physical basis for this enhancement was not completely characterized, the effect was reproducible in vivo and in vitro. We now hypothesize that microbubble formation does not play a significant role in the acoustic behavior of these contrast agents. Otherwise, attenuation and backscatter would be significantly affected by changes in hydrostatic pressure and acoustic pressure, and would show evidence of scattering agent destruction as the duration of ultrasound exposure increased. Both low power (0.65 MPa) unipolar pulses and high-power (3 MPa) unipolar pulses were used to measure the attenuation coefficient of Optison and that of the emulsion. The coefficient was also measured using a high-power unipolar pulse preceded by 5 cycles of a 1 MHz sine-wave of the same amplitude, emitted at a high repetition frequency (5 kHz). Both specimens were held in a pressurized chamber in a water bath maintained at temperatures ranging from 37/spl deg/ to 50/spl deg/C. The emulsion nanoparticles were produced by methods standard in our laboratory using perfluorooctyl bromide (PFOB: boiling point 142/spl deg/C) as the major component. Particle size was measured at 276 nm. We varied ambient hydrostatic pressure (-50 to 200 mm Hg in 50 mm steps), duration of exposure to the acoustic field (2, 20, 40, 80 s), and peak positive and negative acoustic pressure (0.65 to 3.0 MPa).","PeriodicalId":378705,"journal":{"name":"2002 IEEE Ultrasonics Symposium, 2002. Proceedings.","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124940515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1