In B-mode imaging, lateral resolution is impeded by the size and shape of the ultrasound beam used to create the image. For improved lateral resolution, a focussing method that utilises a beam model calculated using the Fraunhofer far field approximations to enhance the Synthetic Aperture Focussing Technique (SAFT) is proposed. The Beam Model Weighted Synthetic Aperture Focussing Technique (BMW...

In previous work, we developed the crossover SAFT–VR equation of state (SAFT–VRX) for pure fluids by following the crossover approach proposed by Kiselev. The SAFT–VRX equation was shown to be very accurate in the prediction of PVT and phase behaviour for both nonassociating and associating fluids. In particular, simple expressions for the potential model parameters for the n-alkane homologous ...

In this work, we extend the pure fluid crossover statistical associating fluid theory (HRX-SAFT) equation of state (EOS) (Kiselev et al., Fluid Phase Equilib. 2001, 183-184, 53) to fluid mixtures of polar and associating components. HRX-SAFT incorporates non-analytic scaling laws in the critical region and is transformed into the analytical, classical HR-SAFT EOS far away from the critical poin...

The Special Affine Fourier Transformation or the SAFT generalizes a number of well known unitary transformations as well as signal processing and optics related mathematical operations. Shift-invariant spaces also play an important role in sampling theory, multiresolution analysis, and many other areas of signal and image processing. Shannon’s sampling theorem, which is at the heart of modern d...

The molecular-based SAFT equation of state has proven to be very versatile in the prediction of fluid phase equilibria. However, in common with all analytic equations of state, SAFT exhibits classical behavior in the critical region rather than the nonanalytical, singular behavior seen in real fluids. As a result, accurate agreement over the whole phase diagram cannot be obtained and must be lo...

INTRODUCTION New fast and efficient multi-channel ultrasonic echo measurement systems are currently introduced for practical applications in NDT-CE [ 1, 2]. The acquired multi-offset data are currently processed and imaged by the synthetic aperture focussing technique (SAFT, see e.g. [ 3, 4]). The application of SAFT, which is closely related to the seismic Kirchhoff migration method, is succes...

3D ultrasonic inspection equipment “Matrixeye” can visualize defects as 3D image with good resolution by the 3D SAFT (Synthetic Aperture Focusing Technique) imaging method. High-speed 3D SAFT imaging process can be achieved by the developed parallel signal process of the ultrasonic echo data collected by a linear or a matrix-array ultrasonic probe. It has the following features. •3D image with ...

Acoustic-resolution photoacoustic microscopy (ARPAM) plays an important role in studying the microcirculation system of biological tissues with deep penetration. High lateral resolution of ARPAM is achieved by using a high numerical aperture acoustic transducer. The deteriorated lateral resolution in the out-of-focus region can be alleviated by synthetic aperture focusing technique (SAFT). Prev...

The synthetic aperture focusing technique (SAFT) is often used for imaging in non-destructive ultrasonic testing. Conventional SAFT is well suited for contact testing of homogeneous objects because of the constant sound speed throughout the media, whereas the refraction present in the practically important case of immersion tests has so far prevented a widespread use of SAFT for such data. Fort...

in this work, the pc-saft equation of state (eos) has been used to model the solubility of acid gases (co2 and h2s) in two imidazolium-based ionic liquids (ils) ([c8-mim][pf6] and [c8-mim][tf2n]). parameters of pure ils were estimated using experimental densities. two strategies were considered to model densities of pure ils. in strategy 1, ils were modeled as nonassociating compounds and in st...