The axial dispersion coefficient of hexachlorobenzene in supercritical carbon dioxide is investigated in a fixed-bed packed with glass beads. The on-line chromatographic pulse-response experiment is used in order to study the dynamics of a packed column under supercritical conditions. The radial dispersion is assumed negligible because of the packed column geometry. To estimate the axial disper...

Experiments are carried out to study static pressure distribution and drag variations over NACA0018 aerofoil and over an automobile dome. Static pressure coefficients are calculated along the chord length for different angles of attack for both the test models and the results are compared. Further, the relationship between coefficient of drag and Reynolds number has been arrived for different a...

In this study, condensation heat transfer coefficients of R-410A were obtained in flattened stainless tubes made from 5.0 mm inner diameter round tubes. The test range covered saturation temperature 45 , heat flux 10 °C kW/m, mass flux 100~400 kg/ms and quality 0.2~0.8. Results showed the effect of aspect ratio on condensation heat transfer coefficient was dependent on the flow pattern. For ann...

Peripheral (brachial) pulse pressure normally exceeds central (aortic) pulse pressure but is a less powerful predictor of cardiovascular risk. The difference between the 2 variables, called pulse pressure amplification, has never been specifically studied between the proximal and distal aorta in coronary patients. Our goal was to determine aortic pulse pressure amplification in subjects at high...

To observe and analyze the effects of continuous positive airway pressure (CPAP) ventilation on advanced glycation end products (AGEs) and oxidized low density lipoprotein (ox-LDL) levels in patients with obstructive sleep apnea hypopnea syndrome (OSAHS), 60 patients with OSAHS were selected as the case group, and 30 patients with simple snoring were selected as the control group. The patients ...

Two sets of hydrogenated microcrystalline silicon thin-film samples were prepared by Plasma Enhanced Chemical Vapor Deposition (PECVD) technique at different deposition conditions of excited power and pressure. The correlation between the crystalline volume fraction for the samples determined from Raman spectra and the excited power, pressure, absorption coefficient, refractive index and optica...

In photo-acoustic imaging, energy absorption causes thermo-elastic expansion of optical absorbers, which in turn leads to propagation of a pressure wave. Recently, we have developed an efficient method for locating small absorbing regions inside a bounded domain from boundary measurements of the induced pressure wave and reconstructing the absorbed density. However, it is the absorption coeffic...

This paper deals with the heat exchange performance prediction of a counter flow double-tube condenser for binary natural refrigerant mixtures (propane/n-butane & propane/i-butane ). The local characteristics of the heat transfer and pressure drop are calculated using a prediction method developed by authors, and the total pressure drop, the overall heat transfer coefficient and the average hea...

This note studies the accuracy of Isogeometric Analysis (IGA) applied in the simulation of incompressible flows around a cylinder in two and three dimensions. Quantities of interest, like the drag coefficient, the lift coefficient, and the difference of the pressure between the front and the back of the cylinder are monitored. Results computed with standard finite element methods are used for c...

in this study, the turbulent kinetic energy redistribution process is investigated. to this aim, the direct numerical simulation (dns) of incompressible flow of a newtonian fluid through a channel at a shear reynolds number of reτ = 180 is used to produce a flow data base. then, these data are statistically analyzed. the turbulent kinetic energy redistribution is studied using the pressure-stra...