HEAD-ON COLLISIONS OF TWO SOLITARY WAVES WITH DIFFERENT AMPLITUDES USING IMAGING TECHNIQUES

The behavior of two unequal solitary waves during head-on collision was experimentally studied by optical and particle-tracer methods. Spatial surface profiles were measured using the particle mask correlation method and the image thresholding method, which detects the air–water boundary as a set of locally extreme luminance values. The measured surface displacement of the colliding wave was compared with the corresponding shape of a third-order perturbation approximation. In addition, to estimate the phase shift from the crest at an arbitrary point, the instantaneous surface variations were measured by two wave gauges. The kinetic features of the target and the oncoming and colliding waves were measured by a particle image velocimetry method. To solve the phase shift, we acquired the velocity fields of the colliding waves in a series of experiments and could show our technological advantage over others.

Thermal Natural Convection Analysis of Olive Oil in Different Cookware Materials for Induction Stoves

This manuscript describes the analysis of temperature and the distribution of natural convection flow of three different cookware materials composed of stainless steel, aluminum and enameled iron, when heating olive oil. A Computational Fluid Dynamic (CFD) software, called COMSOL Multiphysics©, has been used to analyze the heat transfer process for this study. In addition, a thermographic camera and a particle tracer were employed to compare the measurements of temperature, heat transfer and flow velocity, obtained from the CFD analysis. The results demonstrated that the enameled iron was the best choice of cookware material for induction stoves, as with the increment of oil temperature, this material had the biggest contrails and oil velocity convection flow in the center of the cookware.

Calculations of the integral invariant coordinates <I>I</I> and <I>L</I>* in the magnetosphere and mapping of the regions where <I>I</I> is conserved, using a particle tracer (ptr3D v2.0), LANL*, SPENVIS, and IRBEM

The integral invariant coordinate I and Roederer's L or L* are proxies for the second and third adiabatic invariants, respectively, that characterize charged particle motion in a magnetic field. Their usefulness lies in the fact that they are expressed in more instructive ways than their counterparts: I is equivalent to the path length of the particle motion between two mirror points, whereas L*, although dimensionless, is equivalent to the distance from the center of the Earth to the equatorial point of a given field line, in units of Earth radii, in the simplified case of a dipole magnetic field. However, care should be taken when calculating the above invariants, as the assumption of their conservation is not valid everywhere in the Earth's magnetosphere. This is not clearly stated in state-of-the-art models that are widely used for the calculation of these invariants. The purpose of this work is thus to investigate where in the near-Earth magnetosphere we can safely calculate I and L* with tools with widespread use in the field of space physics, for various magnetospheric conditions and particle initial conditions. More particularly, in this paper we compare the values of I and L* as calculated using LANL*, an artificial neural network developed at the Los Alamos National Laboratory, SPENVIS, a space environment online tool, IRBEM, a software library dedicated to radiation belt modeling, and ptr3D, a 3-D particle tracing code that was developed for this study. We then attempt to quantify the variations between the calculations of I and L* of those models. The deviation between the results given by the models depends on particle initial position, pitch angle and magnetospheric conditions. Using the ptr3D v2.0 particle tracer we map the areas in the Earth's magnetosphere where I and L* can be assumed to be conserved by monitoring the constancy of I for energetic protons propagating forwards and backwards in time. These areas are found to be centered on the noon area, and their size also depends on particle initial position, pitch angle and magnetospheric conditions.

Simulation and Experiment of Residence Time Distribution in Short-Contact Cyclone Reactors

The Eulerian-Eulerian model and species transport method were used for the residence time distribution (RTD) predictions of the short-contact cyclone reactor. A video camera and colored particle tracer were employed in the experiment. The component concentration distribution and RTD characteristics were analyzed. The results indicate that the vacuum gas oil (VGO) and catalysts flow down spirally along the wall and the gasoline and dry gas are mostly in the central part, so the VGO has more contact time with catalysts than other gas components. The RTDs indicate that there exists vortex, backflow and other secondary flow in the reactor. The simulated results show a good agreement with the experimental data.

Preparation and Quantification of Radioactive Particles for Tracking Hydrodynamic Behaviour in Multiphase Reactors

Radioactive Particle Tracking (RPT) technique has emerged as a potential and versatile technique, both in terms of richness of information and applicability to a variety of multiphase flow systems. RPT is not an off-the-shelf technique and thus has to be developed by the intended user. This paper is intended to present a simple method and procedure for preparing suitable radioactive particles tracer (Au-198 and Sc-46) irradiated simultaneously with neutrons using TRIGA Mark II research reactor. These present work focuses on the performance evaluation of encapsulated gold and scandium particle to be used as single radioactive particle tracer using qualitative and quantitative neutron activation analysis (NAA) and X-ray micro computed tomography (micro-CT) scanner installed at Malaysian Nuclear Agency.