introduction: air pollution is one of the problems of the recent century caused by vehicles, industries and other urban activities. the city of yazd faces air pollution due to its high population, vehicular traffic and industrial places around the city. one of the important parameters of air pollution is suspended air particles that have harmful effects on the health of people, plants and objec...

a comprehensive mathematical model based on the discrete particle model and computational fluid dynamics was utilized to investigate mixing and segregation of particles in fluidized beds at high pressure. to quantify the extent of mixing in the bed, the lacey mixing index was used. simulations were carried out with different mass fractions of small particles at various pressures ranging from 1 ...

automotive and aerospace industries are required to light materials which have high properties. this causes to reduce production cost and fuel consumption. one of these advanced materials that have been attracted at these decades is particulate metal matrix nanocomposites. these materials have a combination of ductile matrix alloy properties and ceramic reinforcement nanoparticles. powder metal...

bachground: hadron therapy is a novel technique of cancer radiation therapy which employs charged particles beams, 1 h and light ions in particular. due to their physical and radiobiological properties, they allow one to obtain a more conformal treatment, sparing better the healthy tissues located in proximity of the tumor and allowing a higher control of the disease.   objective: as it is well...

incorporation of copper species into silica matrix was performed by the sol-gel method. copper ions and copper particles were doped using two different copper sources; cu(no3)2.3h2o and copper particles chemically synthesized.the particles of copper metallic, cuprous and cupric oxide were prepared and the synthesis and characterizations of copper species were compared together. on the other han...

Electrospray was employed upstream of an electrostatic precipitator (ESP) to enhance the collection efficiency of monodisperse nanometer-sized particles. The electrospray of deionized water produced water droplets with a size range from several tens to several hundreds μm. The visible combined effect of the ESP with the electrospray was found for the collection of particles larger than about 20...

We investigated the effects of estrogen and simvastatin, administered both alone and in combination, on the plasma lipid levels and lipoprotein-related enzymes in 45 postmenopausal women with type IIa hypercholesterolemia. They received 0.625 mg conjugated equine estrogen (n=15), 5 mg simvastatin (n=15), or the combination (n=15) daily for 3 months. We measured the concentrations of cholesterol...

this paper proposes a method to solve multi-objective problems using improved particle swarm optimization. we propose leader particles which guide other particles inside the problem domain. two techniques are suggested for selection and deletion of such particles to improve the optimal solutions. the first one is based on the mean of the m optimal particles and the second one is based on appoin...