Results 171 to 180 of about 514,588 (251)
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Ultrasonic liver scanning: automated A-scan analysis
Physics in Medicine & Biology, 1973The method used to investigate the effect of phase of respiration on the two derived parameters, mean log echo amplitude and slope. The increased mean log echo amplitude in cirrhosis is confirmed. Maximal inspiration is found to be associated with a reduction in mean log echo amplitude when compared with interrupted quiet respiration in a group of ...
R A, Mountford +2 more
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, 2020
Multiple defects including fiber waviness, resin rich layers, porosity and delamination may develop in aerospace composite structures during manufacturing and service, and thus potentially cause structural failure.
Zhen Zhang +3 more
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Multiple defects including fiber waviness, resin rich layers, porosity and delamination may develop in aerospace composite structures during manufacturing and service, and thus potentially cause structural failure.
Zhen Zhang +3 more
semanticscholar +1 more source
Measurement of focused ultrasonic fields using a scanning laser vibrometer
The Journal of the Acoustical Society of America, 2007With the development of optical techniques, scanning laser vibrometers have been applied successfully in measuring particle velocities and distributions in ultrasonic fields. In this paper, to develop the optical interferometry in measuring focused fields with small amplitude, the “effective” refractive index used for plane waves and extended for ...
Yuebing, Wang +3 more
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A-scan ultrasonic system for real time automatic cataract detection
Health and Technology, 2020Cataract is an ocular condition associated to the loss of the normal crystalline lens transparency, and its progression can result in a total loss of vision. The gold standard diagnostic method consists on qualitative observation through a slit lamp. This method has two limitations: incipient cataract may not be detected and the cataract hardness is ...
Lorena Petrella +8 more
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Rail Defect Detection Using Ultrasonic A-Scan Data and Deep Autoencoder
Transportation Research Record: Journal of the Transportation Research Board, 2023Rail defects, especially transverse defects (TDs), can pose risks to safe and efficient railroad operations. Effective rail defect detection is critical for the prevention of broken rail-induced accidents and derailments. In this study, a deep autoencoder (DAE) rail defect detection framework is developed to process ultrasonic A-scan data collected by
Yuning Wu, Xuan Zhu
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A scan conversion CMOS implementation for a portable ultrasonic system
CCECE 2003 - Canadian Conference on Electrical and Computer Engineering. Toward a Caring and Humane Technology (Cat. No.03CH37436), 2004Digital scan conversion is the process of converting received ultrasound signals (echoes) in multiscan lines, at varying angles (polar coordinate), to a Cartesian raster format for displaying. This conversion is necessary for compatibility with LCD and CRT monitors. To avoid artifacts during the conversion process the processed data are interpolated to
A. Kassem, M. Sawan, M. Boukadoum
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Ultrasonic compared with hand instrumentation: A scanning electron microscope study
Journal of Endodontics, 1988Scanning electron micrographs were used to compare the effectiveness of two methods of cleansing, shaping, and enlarging root canals of human teeth. Eleven extracted maxillary central incisors were instrumented by ultrasonically activated K files and diamond files with a constant high volume of 2.625% NaOCl irrigation.
M C, Baker +3 more
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Towards a-scan imaging via Ultrasonic Vibration Potential measurements
Nuclear Engineering and Design, 2011Abstract A potential of a 1-D imaging technique utilizing Ultrasonic Vibration Potential (UVP) is reported in the paper, in which ultrasound is used to vibrate charged particles or ions in colloids, producing electric dipole moments and generating electrical signals which are in relation to their properties.
Peng Guan +4 more
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Ophthalmic A-scan ultrasonic measuring instrument based on MSP430
2010 3rd International Conference on Biomedical Engineering and Informatics, 2010This paper schemed out an ophthalmic high frequency A-scan ultrasonic instrument to measure corneal thickness and ocular axial length, using pulse reflection principle and double counting method. A special ultrasonic high frequency transducer was designed to get higher resolution. In addition, differential circuit reduced the pulse width, thus improved
Juan Chen, Xingqun Zhao
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Mapping high power ultrasonic fields using a scanned scatterer
The Journal of the Acoustical Society of America, 2002The conventional method used to map the field of high intensity focused ultrasound (HIFU) transducers displaces a hydrophone over a grid of points in the zone of interest and provides a direct measure of the ultrasound pressure at each point. The approach has several major limitations: (1) the hydrophone is likely to be damaged while repeatedly ...
Bryan Cunitz, Peter Kaczkowski
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