numerous investigations have been devoted towards understanding the hydrodynamics of gas jets in fluidized beds. however, most of them address the problem from  macroscopic point of view, which does not reveal the true behavior in the jet region at the single particle level. the present work aims to understand the jet behavior from a more fundamental level, i.e. the individual particle level. a...

a two-dimensional single particle finite element model was used to examine the effects of particle fragmental pattern on the average molecular weights, polymerization rate and particle overheating in heterogeneous ziegler-natta olefin polymerization. a two-site catalyst kinetic mechanism was employed together with a dynamic two-dimensional molecular species in diffusion-reaction equation. the i...

in this article, multiple-product pvrp with pickup and delivery that is used widely in goods distribution or other service companies, especially by railways, was introduced. a mathematical formulation was provided for this problem. each product had a set of vehicles which could carry the product and pickup and delivery could simultaneously occur. to solve the problem, two meta-heuristic methods...

numerous problems encountered in real life cannot be actually formulated as a single objective problem; hence the requirement of multi-objective optimization (moo) had arisen several years ago. due to the complexities in such type of problems powerful heuristic techniques were needed, which has been strongly satisfied by swarm intelligence (si) techniques. particle swarm optimization (pso) has ...

in this paper, a new enhanced version of the particle swarm optimization (pso) is presented. an important modification is made by adding probabilistic functions into pso, and it is named probabilistic particle swarm optimization (ppso). since the variation of the velocity of particles in pso constitutes its search engine, it should provide two phases of optimization process which are: explorati...

introduction: particle size and distribution can influence the properties of materials. this study analyzed and compared the particle size of root mta, calcium hydroxide (ch), and a new endodontic cement called calcium enriched material (cem). materials and methods: the particle size of each material was analyzed three times using 0.05 mg of test material with a particle size analyzer. the part...

in this research, the effect of bubble surface area flux, sb, and particle size on flotation rate constant, k, of pyrite (fes2) particles was studied using bubble-particle interactions. the bubble-particle collision, attachment and detachment efficiencies were calculated under different flow regimes. the k increased with increase in the collision efficiency and decrease in the detachment effici...

the current regulated particle metric in vehicle emissions is the total mass, while during last decade interest in number size distribution has increased. various international studies on epidemiology and toxicology have reported the adverse effect of the particle matter on public health. the unece group of experts on pollution and energy (grpe) under particle measurement program (pmp) are unde...