The Influence of Air Pressure on the Dynamics of Flexural Ultrasonic Transducers.

The flexural ultrasonic transducer comprises a piezoelectric ceramic disc bonded to a membrane. The vibrations of the piezoelectric ceramic disc induce flexural modes in the membrane, producing ultrasound waves. The transducer is principally utilized for proximity or flow measurement, designed for operation at atmospheric pressure conditions. However, there is rapidly growing industrial demand for the flexural ultrasonic transducer in applications including water metering or in petrochemical plants where the pressure levels of the gas or liquid environment can approach 100 bar. In this study, characterization methods including electrical impedance analysis and pitch-catch ultrasound measurement are employed to demonstrate the dynamic performance of flexural ultrasonic transducers in air at elevated pressures approaching 100 bar. Measurement principles are discussed, in addition to modifications to the transducer design for ensuring resilience at increasing air pressure levels. The results highlight the importance of controlling the parameters of the measurement environment and show that although the conventional design of flexural ultrasonic transducer can exhibit functionality towards 100 bar, its dynamic performance is unsuitable for accurate ultrasound measurement. It is anticipated that this research will initiate new developments in ultrasound measurement systems for fluid environments at elevated pressures.

Flow Velocity Measurement Using a Spatial Averaging Method with Two-Dimensional Flexural Ultrasonic Array Technology.

Accurate average flow velocity determination is essential for flow measurement in many industries, including automotive, chemical, and oil and gas. The ultrasonic transit-time method is common for average flow velocity measurement, but current limitations restrict measurement accuracy, including fluid dynamic effects from unavoidable phenomena such as turbulence, swirls or vortices, and systematic flow meter errors in calibration or configuration. A new spatial averaging method is proposed, based on flexural ultrasonic array transducer technology, to improve measurement accuracy and reduce the uncertainty of the measurement results. A novel two-dimensional flexural ultrasonic array transducer is developed to validate this measurement method, comprising eight individual elements, each forming distinct paths to a single ultrasonic transducer. These paths are distributed in two chordal planes, symmetric and adjacent to a diametral plane. It is demonstrated that the root-mean-square deviation of the average flow velocity, computed using the spatial averaging method with the array transducer is 2.94%, which is lower compared to that of the individual paths ranging from 3.65% to 8.87% with an average of 6.90%. This is advantageous for improving the accuracy and reducing the uncertainty of classical single-path ultrasonic flow meters, and also for conventional multi-path ultrasonic flow meters through the measurement via each flow plane with reduced uncertainty. This research will drive new developments in ultrasonic flow measurement in a wide range of industrial applications.

The Dynamic Performance of Flexural Ultrasonic Transducers.

Flexural ultrasonic transducers are principally used as proximity sensors and for industrial metrology. Their operation relies on a piezoelectric ceramic to generate a flexing of a metallic membrane, which delivers the ultrasound signal. The performance of flexural ultrasonic transducers has been largely limited to excitation through a short voltage burst signal at a designated mechanical resonance frequency. However, a steady-state amplitude response is not generated instantaneously in a flexural ultrasonic transducer from a drive excitation signal, and differences in the drive characteristics between transmitting and receiving transducers can affect the measured response. This research investigates the dynamic performance of flexural ultrasonic transducers using acoustic microphone measurements and laser Doppler vibrometry, supported by a detailed mechanical analog model, in a process which has not before been applied to the flexural ultrasonic transducer. These techniques are employed to gain insights into the physics of their vibration behaviour, vital for the optimisation of industrial ultrasound systems.

Cryopreserved, Xeno-Free Human Umbilical Cord Mesenchymal Stromal Cells Reduce Lung Injury Severity and Bacterial Burden in Rodent Escherichia coli-Induced Acute Respiratory Distress Syndrome.

OBJECTIVE: Although mesenchymal stem/stromal cells represent a promising therapeutic strategy for acute respiratory distress syndrome, clinical translation faces challenges, including scarcity of bone marrow donors, and reliance on bovine serum during mesenchymal stem/stromal cell proliferation. We wished to compare mesenchymal stem/stromal cells from human umbilical cord, grown in xeno-free conditions, with mesenchymal stem/stromal cells from human bone marrow, in a rat model of Escherichia coli pneumonia. In addition, we wished to determine the potential for umbilical cord-mesenchymal stem/stromal cells to reduce E. coli-induced oxidant injury. DESIGN: Randomized animal study. SETTING: University research laboratory. SUBJECTS: Male Sprague-Dawley rats. INTERVENTIONS: Acute respiratory distress syndrome was induced in rats by intratracheal instillation of E. coli (1.5-2 × 10 CFU/kg). "Series 1" compared the effects of freshly thawed cryopreserved umbilical cord-mesenchymal stem/stromal cells with bone marrow-mesenchymal stem/stromal cells on physiologic indices of lung injury, cellular infiltration, and E. coli colony counts in bronchoalveolar lavage. "Series 2" examined the effects of cryopreserved umbilical cord-mesenchymal stem/stromal cells on survival, as well as measures of injury, inflammation and oxidant stress, including production of reactive oxidative species, reactive oxidative species scavenging by superoxide dismutase-1 and superoxide dismutase-2. MEASUREMENTS AND MAIN RESULTS: In "Series 1," animals subjected to E. coli pneumonia who received umbilical cord-mesenchymal stem/stromal cells had improvements in oxygenation, respiratory static compliance, and wet-to-dry ratios comparable to bone marrow-mesenchymal stem/stromal cell treatment. E. coli colony-forming units in bronchoalveolar lavage were reduced in both cell therapy groups, despite a reduction in bronchoalveolar lavage neutrophils. In series 2, umbilical cord-mesenchymal stem/stromal cells enhanced animal survival and decreased alveolar protein and proinflammatory cytokine concentrations, whereas increasing interleukin-10 concentrations. Umbilical cord-mesenchymal stem/stromal cell therapy decreased nicotinamide adenine dinucleotide phosphate-oxidase 2 and inducible nitric oxide synthase and enhanced lung concentrations of superoxide dismutase-2, thereby reducing lung tissue reactive oxidative species concentrations. CONCLUSIONS: Our results demonstrate that freshly thawed cryopreserved xeno-free human umbilical cord-mesenchymal stem/stromal cells reduce the severity of rodent E. coli-induced acute respiratory distress syndrome. Umbilical cord-mesenchymal stem/stromal cells, therefore, represent an attractive option for future clinical trials in acute respiratory distress syndrome.

A New Electromagnetic Acoustic Transducer Design for Generating and Receiving S0 Lamb Waves in Ferromagnetic Steel Plate.

Electromagnetic acoustic transducers (EMATs) are non-contact, ultrasonic transducers that are usually kept within 5 mm from the sample surface to obtain a sufficient signal-to-noise ratio (SNR). One important issue associated with operation on a ferromagnetic plate is that the strong attraction force from the magnet can affect measurements and make scanning difficult. This paper investigates a method to generate fundamental, symmetric Lamb waves on a ferromagnetic plate. A coil-only, low-weight, generation EMAT is designed and investigated, operating at lift-offs of over 5 mm. Another design of an EMAT is investigated using a rectangular magnet with a much higher lift-off than the coil, of up to 19 mm. This results in a much lower force between the EMAT and sample, making scanning the EMAT much easier.

Comparing the case mix and survival of women receiving breast cancer care from one private provider with other London women with breast cancer: pilot data exchange and analyses.

BACKGROUND: Data from providers of private cancer care are not yet formally included in English cancer registration data. This study aimed to test the exchange of breast cancer data from one Hospital Corporation of America International (HCAI) hospital in London with the cancer registration system and assess the suitability of these data for comparative analyses of case mix and adjusted survival. METHODS: Data on 199 London women receiving 'only HCAI care', 278 women receiving 'some HCAI care' (HCAI and other services), and 31,234 other London women diagnosed between 2005 and 2011 could be identified and compared. Overall survival was estimated using the Kaplan-Meier method, and Cox regression was used to adjust for age, socioeconomic deprivation, year of diagnosis, stage of disease and recorded treatment. RESULTS: Women receiving 'only HCAI care' were younger, lived in areas of higher affluence (47.8 % vs 27.6 %) and appeared less likely to be recorded as having screen-detected (2.5 % vs 25.0 %) disease than other London women. Women receiving 'some HCAI care' were more similar to 'HCAI only' women. Although HCAI stage of disease data completeness improved during the study period, this was less complete overall than cancer registration data and limited the comparative survival analyses. An apparent survival advantage for 'HCAI only' women compared with other London women (hazard ratio 0.48, 95 % confidence interval (CI): 0.32-0.74) was attenuated and no longer statistically significant after adjustment (0.79, 95 % CI: 0.51-1.21). Women receiving 'some HCAI care' appeared to have higher survival (hazard ratio 0.24, 95 % CI 0.14-0.41) which was attenuated to 0.48 (95 % CI: 0.28-0.80) in the fully adjusted model. CONCLUSIONS: Exchange of data between the private cancer sector and the English cancer registration service can identify patients who receive all or some private care. The better survival of women receiving only or some HCAI breast cancer care appears to be at least partly explained by demographic, disease, and treatment factors. However, larger studies using similarly quality assured datasets and more complete staging data from the private sector are needed to produce definitive comparative results.

Experimental Evaluation of Three Designs of Electrodynamic Flexural Transducers.

Three designs for electrodynamic flexural transducers (EDFT) for air-coupled ultrasonics are presented and compared. An all-metal housing was used for robustness, which makes the designs more suitable for industrial applications. The housing is designed such that there is a thin metal plate at the front, with a fundamental flexural vibration mode at ∼50 kHz. By using a flexural resonance mode, good coupling to the load medium was achieved without the use of matching layers. The front radiating plate is actuated electrodynamically by a spiral coil inside the transducer, which produces an induced magnetic field when an AC current is applied to it. The transducers operate without the use of piezoelectric materials, which can simplify manufacturing and prolong the lifetime of the transducers, as well as open up possibilities for high-temperature applications. The results show that different designs perform best for the generation and reception of ultrasound. All three designs produced large acoustic pressure outputs, with a recorded sound pressure level (SPL) above 120 dB at a 40 cm distance from the highest output transducer. The sensitivity of the transducers was low, however, with single shot signal-to-noise ratio ( SNR ) ≃ 15 dB in transmit-receive mode, with transmitter and receiver 40 cm apart.

Socioeconomic and ethnic inequalities in screen-detected breast cancer in London.

BACKGROUND: We investigated socioeconomic and ethnic inequalities in screen-detected breast cancer in London-a city with relatively low breast cancer screening uptake and a diverse population. METHODS: Data on 11 957 breast cancers in London women aged 50-64 between 1998 and 2005 were extracted from the Thames Cancer Registry. We investigated the relationship between socioeconomic deprivation and the incidence and 5-year relative survival of screen-detected and non screen-detected cancers. Using logistic regression analysis we explored whether differences in screen-detected cancers between White, Asian and Black women were influenced by age and socioeconomic deprivation. RESULTS: The incidence of screen-detected breast cancer was lower in deprived women and their 5-year relative survival was worse than affluent women. However, survival differences were smaller for screen-detected disease. Among women with breast cancer the odds ratios (OR) for screen-detected disease differed between ethnic groups and these differences were not influenced by adjustment for age and deprivation. Compared with White women, Indian women had higher odds (OR 1.50, 95% confidence interval (1.23-1.84)], and Black Caribbean [0.68 (0.54-0.87)] and Black African women [0.53 (0.38-0.76)] significantly lower odds. CONCLUSION: A sustained focus on increasing screening uptake among deprived women and in Black communities could decrease inequalities in early diagnosis.

The wave-field from an array of periodic emitters driven simultaneously by a broadband pulse.

The use of phased array methods are commonplace in ultrasonic applications, where controlling the variation of the phase between the narrowband emitters in an array facilitates beam steering and focusing of ultrasonic waves. An approach is presented here whereby emitters of alternating polarity arranged in a one-dimensional array are pulsed simultaneously, and have sufficiently wide, controlled bandwidth to emit a two-dimensional wave. This pulsed approach provides a rapid means of simultaneously covering a region of space with a wave-front, whereby any wave that scatters or reflects off a body to a detector will have a distinct arrival time and frequency. This is a general wave phenomenon with a potential application in radar, sonar, and ultrasound. The key result is that one can obtain a smooth, continuous wave-front emitted from the array, over a large solid angle, whose frequency varies as a function of angle to the array. Analytic and finite element models created to describe this phenomenon have been validated with experimental results using ultrasonic waves in metal samples.

One-dimension frequency-wavenumber-domain based model for ultrasonic waves generated by dual-array transducers.

Array transducers can allow wavelength and frequency selectivity and can be used to generate different types of waves, such as ultrasonic bulk or guided waves. Dual-array transducers consist of two interlaced arrays, where the elements of each array are electrically connected. Therefore, by driving each array with a pair of phased pulses one can achieve a degree of wave generation control that allows unidirectional generation, unlike single array transducers that generate waves in both 0° and 180° directions with respect to the array's longitudinal axis. In this paper, we present a one-dimensional analytical model to determine the ultrasonic waves generated by dual-array transducers based on the excitability of the array in the frequency-wavenumber domain, the so-called operation region, determined by the joint spatial and temporal spectrum of the dual-array. We further exploited it to analyse the effectiveness of unidirectional generation with time-delayed excitation signals that provide ideal constructive or destructive interferences. The model also provides the time-domain received waveforms, which were compared to experimentally generated shear-horizontal ultrasonic guided waves, with a dual periodic permanent magnet array electromagnetic acoustic transducer, showing very good agreement. The adequate selection of the excitation signal allowed one to obtain up to about 40 dB unidirectionality experimentally.

Miniature Ferroelectret Microphone Design and Performance Evaluation Using Laser Excitation.

Miniature microphones suitable for measurements of ultrasonic wave field scans in air are expensive or lack sensitivity or do not cover the range beyond 100 kHz. It is essential that they are too large for such fields measurements. The use of a ferroelectret (FE) film is proposed to construct a miniature, needle-style 0.5-mm-diameter sensitive element ultrasonic microphone. FE has an acoustic impedance much closer to that of air compared with other alternatives and is low cost and easy to process. The performance of the microphone was evaluated by measuring the sensitivity area map, directivity, ac response, and calibrating the absolute sensitivity. Another novel contribution here is that the sensitivity map was obtained by scanning the focused beam of a laser diode over the microphone surface, producing thermoelastic ultrasound excitation. The electroacoustic response of the microphone served as a sensitivity indicator at a scan spot. Micrometer scale granularity of the FE sensitivity was revealed in the sensitivity map images. It was also demonstrated that the relative ac response of the microphone can be obtained using pulsed laser beam thermoelastic excitation of the whole microphone surface with a laser diode. The absolute sensitivity calibration was done using the hybrid three-transducer reciprocity technique. A large aperture, air coupled transducer beam was focused onto the microphone surface, using the parabolic off-axis mirror. This measurement validated the laser ac response measurements. The FE microphone performance was compared with biaxially stretched polyvinylidene difluoride (PVDF) microphone of the same construction.

Application of the reciprocity principle to evaluation of mode-converted scattered shear horizontal (SH) wavefields in tapered thinning plates.

The interaction of guided waves with wall thinning can be complex, depending on the thinning geometry and the frequency. At a high frequency-thickness, when a shear-horizontal (SH) guided wave mode impinges upon a tapered wall thinning region, there is mode conversion to other propagating SH modes, either in reflection or transmission, which heavily depends on the shape of the taper. In this paper, we have combined the reciprocity theorem of elastodynamics and the theory of multiple reflections, in order to analytically calculate the scattered SH wavefield in plates, due to the interaction with an arbitrary tapered thinning. The taper is discretized into several sections and the formulation is addressed in matrix notation, in order to tackle several modes which arise due to mode interconversion distributed within the taper. The method was validated with experimental and numerical data at linear tapered thinning, in the high-frequency-thickness regime. It was also applied to provide understanding of the reflection behaviour within smoother taper profiles, namely, raised-cosine and Blackman window tapers, and to visualize the propagating field of each mode. It is shown that for a linear taper profile, the reflection within the taper is virtually constant, which produces an interference pattern in the overall reflection from the whole taper. Such a mechanism is broken with smoother tapers, since they impose lower reflection close to the taper ends. The method proves itself useful for analytically investigating the scattering from arbitrary wall thinning when mode-conversion arises.

Unidirectional Shear Horizontal Wave Generation by Periodic Permanent Magnets Electromagnetic Acoustic Transducer With Dual Linear-Coil Array.

Shear horizontal (SH) waves are commonly generated by periodic permanent magnet (PPM) electromagnetic acoustic transducers (EMATs) in metallic media. Conventional PPM EMATs generate ultrasonic waves, which simultaneously propagate both forward and backward. This can be an undesirable characteristic, since the backward wave can be eventually reflected, reaching the receiver transducer where it can mix with the signal of interest. This limitation can be overcome using two side-shifted PPM arrays and racetracks coils to generate SH waves in a single direction. That design relies on the EMAT wavefront diffraction to produce constructive and destructive interference, but produces unwanted backward traveling sidelobes. Here, we present a different design, which uses a conventional PPM array and a dual linear-coil array. The concept was numerically simulated, the main design parameters were assessed and the unidirectional EMAT was experimentally evaluated on an aluminum plate, generating the SH0-guided wave mode nominally in a single direction. The amplitude ratio of the generated waves at the enhanced to the weakened side is above 20 dB. Since the wavefronts from the two sources are perfectly aligned, no obvious backward sidelobes are present in the acoustic field, which can significantly reduce the probability of false alarm of an EMAT detection system.

Mode conversion of SH guided waves with symmetry inversion in plates.

When shear horizontal ultrasonic guided waves interact with thickness discontinuities in plates, the reflected and transmitted wavefields can be composed of several modes due to mode conversion. It is known that in a plate with a symmetric discontinuity, with respect to the plate's mid-plane, mode conversion is restricted to modes that share the same symmetry as the incident mode. In this paper, we use an analytical model based on the reciprocity principle and finite element analysis to investigate mode conversion due to the interaction with different types of discontinuity, namely, non-symmetric, symmetric and geometrically symmetric but with opposite boundary conditions, that is one side of the discontinuity free and the other rigidly fixed. We show that the reflected field due to interaction with the latter is virtually restricted to modes with the opposite symmetry of the incident one, acting as a symmetry inverter discontinuity. Unlike fully symmetric discontinuities, the effectiveness of a symmetry inverter discontinuity depends on the frequency. This was proved with aid of the analytical model for a full-depth discontinuity and verified for partial depth discontinuities. Finally, symmetry inversion of SH waves was experimentally verified in acrylic plates which were symmetrically machined and filled with steel in one side to mimic a fixed boundary condition.

Estimating attendance for breast cancer screening in ethnic groups in London.

BACKGROUND: Breast screening uptake in London is below the Government's target of 70% and we investigate whether ethnicity affects this. Information on the ethnicity for the individual women invited is unavailable, so we use an area-based method similar to that routinely used to derive a geographical measure for socioeconomic deprivation. METHODS: We extracted 742,786 observations on attendance for routine appointments between 2004 and 2007 collected by the London Quality Assurance Reference Centre. Each woman was assigned to a lower super output (LSOA) based on her postcode of residence. The proportions of the ethnic groups within each LSOA are known, so that the likelihood of a woman belonging to White, Black and Asian groups can be assigned. We investigated screening attendance by age group, socioeconomic deprivation using the Index of Deprivation 2004 income quintile, invitation type and breast screening service. Using logistic regression analysis we calculated odds ratios for attendance based on ethnic composition of the population, adjusting for age, socioeconomic status, the invitation type and screening service. RESULTS: The unadjusted attendance odds ratios were high for the White population (OR: 3.34 95% CI [3.26-3.42]) and low for the Black population (0.13 [0.12-0.13]) and the Asian population (0.55 [0.53-0.56]). Multivariate adjustment reduced the differences, but the Black population remained below unity (0.47 [0.44-0.50]); while the White (1.30 [1.26-1.35]) and Asian populations (1.10 [1.05-1.15]) were higher. There was little difference in the attendance between age groups. Attendance was highest for the most affluent group and fell sharply with increasing deprivation. For invitation type, the routine recall was higher than the first call. There were wide variations in the attendance for different ethnic groups between the individual screening services. CONCLUSIONS: Overall breast screening attendance is low in communities with large Black populations, suggesting the need to improve participation of Black women. Variations in attendance for the Asian population require further investigation at an individual screening service level.

Unidirectional Shear Horizontal Wave Generation With Side-Shifted Periodic Permanent Magnets Electromagnetic Acoustic Transducer.

Periodic permanent magnet (PPM) array electromagnetic acoustic transducers (EMATs) can efficiently generate and receive shear horizontal (SH) ultrasonic waves. Conventional PPM EMATs typically generate waves which simultaneously propagate both forward and backward. This can complicate the received signals and make it difficult to locate the position of scatterers. Unidirectional generation of ultrasounds can be achieved if two ultrasonic sources are separated by a predefined distance and are excited with the proper delay. Relying on this principle, EMATs have been previously designed aiming to generate other modes of ultrasonic waves. The main challenge when extending this conception to an SH-wave EMAT is how to restrict each coil to its specific magnet array. We present the concept of a unidirectional SH EMAT consisting of two racetrack coils and two interlaced PPM arrays, that are slightly shifted sideways, in such a way that the generated wavefronts still properly interfere. The design was fabricated and experimentally evaluated in an aluminum plate generating the SH0 guided wave mode. The forward to backward generated wave ratio is above 20 dB and well agrees with finite element simulations.

Phased Electromagnetic Acoustic Transducer Array for Rayleigh Wave Surface Defect Detection.

A phased electromagnetic acoustic transducer (EMAT) array system has been developed for the detection and characterization of surface-breaking defects. An array of four linear coils that are individually controlled is used to generate a Rayleigh wave. The high-current electronics combined with the coil designs enables the array to generate either narrowband or broadband signals, and controlling the phase delay between the channels makes it possible to change the ultrasound wavelength without requiring the physical separation of the coils to be changed. The experimental results show that the four-coil phased array can generate a wavelength range from 3.0 to 11.7 mm. Surface-breaking defects were characterized using a transmit-receive setup with a broadband EMAT detector being used to detect the Rayleigh wave. Machined surface slots with different depths were used for technique validation. The results show that the array is sensitive to surface defects and a wide depth sensitivity range for defect sizing can be easily achieved by applying phasing to tune the wavelength of operation. A large increase in detection flexibility is immediately shown.

Mammographic Breast Density and Urbanization: Interactions with BMI, Environmental, Lifestyle, and Other Patient Factors.

Mammographic breast density (MBD) is an important imaging biomarker of breast cancer risk, but it has been suggested that increased MBD is not a genuine finding once corrected for age and body mass index (BMI). This study examined the association of various factors, including both residing in and working in the urban setting, with MBD. Questionnaires were completed by 1144 women attending for mammography at the London Breast Institute in 2012-2013. Breast density was assessed with an automated volumetric breast density measurement system (Volpara) and compared with subjective radiologist assessment. Multivariable linear regression was used to model the relationship between MBD and residence in the urban setting as well as working in the urban setting, adjusting for both age and BMI and other menstrual, reproductive, and lifestyle factors. Urban residence was significantly associated with an increasing percent of MBD, but this association became non-significant when adjusted for age and BMI. This was not the case for women who were both residents in the urban setting and still working. Our results suggest that the association between urban women and increased MBD can be partially explained by their lower BMI, but for women still working, there appear to be other contributing factors.

Mode Selectivity of SH Guided Waves by Dual Excitation and Reception Applied to Mode Conversion Analysis.

Shear horizontally (SH) guided waves, generated by periodic permanent magnet arrays, have been used previously in nondestructive evaluation of metal plates and pipes. When an SH guided wave interacts with a defect or a change in sample thickness, the incident SH wave may undergo mode conversion. Analysis of mode conversion is complicated, due to the interference of several propagating modes in the received signal that can often temporally overlap. This paper proposes a mode selection technique to help understand the interaction of SH guided waves with changes in sample thickness. Using an understanding of the propagation characteristics of the guided waves, SH guided waves are sequentially generated and detected on both surfaces of the plate, capturing four distinct waveforms. By superposition of the detected signals, symmetric modes can be clearly separated from antisymmetric modes in the processed received signals. For this method to work well, the transducers used should have very similar responses and be precisely positioned on exactly opposite positions either side of the plate. Finite element simulations are also performed, mirroring the experimental measurements, and the results correlate well with the experimental observations made on an 8-mm-thick plate with a region of simulated wall thinning machined into the sample.

Dataset on reflection and transmission coefficients of ultrasonic shear horizontal guided waves in plates with wall thinning.

This data article reports the data for reflection and transmission coefficients of the SH0 and SH1 ultrasonic guided waves modes due to their interaction with tapered wall thinning in aluminium plates. Several thinning depths and edge taper angles were machined, at the total of 35 different samples. Periodic permanent magnet array electromagnet acoustic transducers were used to generate and receive the waves. Both modes were individually generated and separated in the received signal by means of effective post-processing technique. Reflection and transmission coefficients were calculated at both the leading and trailing edges of the thinning region for mode-converted and non-mode converted signals; therefore, eight coefficients were calculated for each generated mode, at the total of sixteen coefficients for each sample. Additional finite-element model was used in order to obtain numerical values for the coefficients. These data were used in order to analyze the interaction of the SH0 and SH1 modes with wall thinning and the capabilities of using them in non-destructive evaluation of corrosion-like defects in the research paper entitled "Interaction of SH guided waves with wall thinning" (Kubrusly et al., 2019).