The effect of tube diameter on two-phase flow patterns was investigated in circular tubes with inner diameters of 0.6, 1.2, 1.7, 2.6, and 3.4mm using air and water. The gas and liquid superficial velocity ranges were 0.01–50 and 0.01–3m/s, respectively. The gas and liquid flow rates were measured and the two-phase flow pattern images were recorded using high-speed CMOS camera. The flow patterns...

This paper presents experimental research on structural behaviour of normal and recycled aggregate concrete filled steel tube (RACFT) columns externally strengthened with carbon fibre reinforced polymer (CFRP) sheets and subjected to axial loading. A total of 22 specimens were tested to investigate the influence of the following variables: (1) tube configurations, circular or square, solid or h...

The impact of photoelectron backscattering on spectral distributions measured with Hybrid Photodetector Tubes has been calculated. The calculations are based on the backscattering coefficient , the average number of photoelectrons phel emitted from the photocathode, and on the distribution of the fractional photoelectron energy absorbed in silicon during the backscattering process. We obtained ...

We investigate numerically and experimentally the spatial collapse dynamics and polarization stability of radially and azimuthally polarized vortex beams in pure Kerr medium. These beams are unstable to azimuthal modulation instabilities and break up into distinct collapsing filaments. The polarization of the filaments is primarily linear with weak circular components at the filaments' boundari...

A hybrid array configuration suitable for wideband millimeter-wave applications is presented in this work. The proposed structure is based on the use of circular waveguide elements electromagnetically coupled trough circular apertures to a stripline distribution network. The adopted excitation mechanism avoids the use of transition components generally reducing the overall antenna efficiency. S...

This study deals with a design procedure of microstrip patch antenna for wireless application. The proposed octagon shaped hybrid coupled microstrip antenna for multiband operation is pertinent in wireless application. By exciting two orthogonal modes by 90° time phase difference in hybrid coupling circular polarization is obtained. The gain is enhanced by introducing tapering at the end of hyb...