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The imaging algorithm for the ultrasonic testing of metal castings by the application of automated testing systems based on a six degree of freedom robotic manipulators

100%

Dolmatov D. , Zhvyrblya V. , Sednev D. , Kroening M.

tom Vol. 18, No. 2

49--57

Complex-shaped surface represents one of the challenges in ultrasonic testing of metal castings. This conditions the growing interest in development and application of the automated testing system based on a six degrees of freedom (DOF) robotic manipulators. This is due to their ability to provide ultrasonic scanning of the curved specimens with high speed. Higher reliability of the results can be obtained via implementation of the imaging algorithms based on Synthetic Aperture Focusing Technique (SAFT) in the named systems. This approach allows to obtain high-resolution imagery of the internal structure of controlled objects with reduced level of grain noise, the latter occurs due to the often encountered coarse-grained structure of metal castings. In this paper, we introduce the novel imaging algorithm for the automated ultrasonic testing system based on a six degree of freedom robotic manipulator. The capabilities of the algorithm were verified by the application of computer simulations in CIVA 2016 software and also via the in situ experiments. In all the cases analyzed the results revealed that the imaging algorithm allows to make precise imagery of the internal structure of the specimens with different curvature. The obtained research results confirmed the suggested algorithm effectiveness, thus making it acceptable for prospective industrial applications.

Analysis of Using Multi-Angle Conventional Ultrasound Scanning for Efficient 3-D Object Imaging

88%

Sabiniok M. , Opieliński K. J. , Lis S. , Sabiniok M. , Opieliński K. J. , Lis S.

Noninvasive Imaging of Thermal Fields Induced in Soft Tissues In Vitro by Pulsed Focused Ultrasound Using Analysis of Echoes Displacement

88%

Karwat P. , Litniewski J. , Kujawska T. , Secomski W. , Krawczyk K.

nr 1

Generating Porosity Spectrum of Carbonate Reservoirs using Ultrasonic Imaging Log

75%

Zhang J. , Nie X. , Xiao S. , Zhang C. , Zhang C. , Zhang Z.

Acta Geophysica

2018

tom Vol. 66, no. 2

191--201

Imaging logging tools can provide us the borehole wall image. The micro-resistivity imaging logging has been used to obtain borehole porosity spectrum. However, the resistivity imaging logging cannot cover the whole borehole wall. In this paper, we propose a method to calculate the porosity spectrum using ultrasonic imaging logging data. Based on the amplitude attenuation equation, we analyze the factors affecting the propagation of wave in drilling fluid and formation and based on the bulk-volume rock model, Wyllie equation and Raymer equation, we establish various conversion models between the reflection coefficient β and porosity φ. Then we use the ultrasonic imaging logging and conventional wireline logging data to calculate the near-borehole formation porosity distribution spectrum. The porosity spectrum result obtained from ultrasonic imaging data is compared with the one from the microresistivity imaging data, and they turn out to be similar, but with discrepancy, which is caused by the borehole coverage and data input difference. We separate the porosity types by performing threshold value segmentation and generate porosity-depth distribution curves by counting with equal depth spacing on the porosity image. The practice result is good and reveals the efficiency of our method.

Assessment of High Frequency Imaging and Doppler System for the Measurements of the Radial Artery Flow-Mediated Dilation

75%

Nowicki A. , Gambin B. , Secomski W. , Trawiński Z. , Szubielski M. , Tymkiewicz R. , Olszewski R.

tom Vol. 44, No. 4

637--644

Objectives: In the article we describe the new, high frequency, 20 MHz scanning/Doppler probe designed to measure the flow mediated dilation (FMD) and shear rate (SR) close to the radial artery wall. Methods: We compare two US scanning systems, standard vascular modality working below 12 MHz and high frequency 20 MHz system designed for FMD and SR measurements. Axial resolutions of both systems were compared by imaging of two closely spaced food plastic foils immersed in water and by measuring systolic/diastolic diameter changes in the radial artery. The sensitivities of Doppler modalities were also determined. The diagnostic potential of a high frequency system in measurements of FMD and SR was studied in vivo, in two groups of subjects, 12 healthy volunteers and 14 patients with stable coronary artery disease (CAD). Results: Over three times better axial resolution was demonstrated for a high frequency system. Also, the sensitivity of the external single transducer 20 MHz pulse Doppler proved to be over 20 dB better (in terms of a signal-to-noise ratio) than the pulse Doppler incorporated into the linear array. Statistically significant differences in FMD and FMD/SR values for healthy volunteers and CAD patients were confirmed, p-values < 0:05. The areas under Receiver Operating Characteristic (ROC) curves for FMD and FMD/SR for the prediction CAD had the values of 0.99 and 0.97, respectively. Conclusions: These results justify the usefulness of the designed high-frequency scanning system to determine the FMD and SR in the radial artery as predictors of coronary arterial disease.