soft-sphere discrete element method (dem) and navier-stokes equations were coupled with equations of energy for gas and solids to investigate the process of agglomeration in fluidized bed of polyethylene particles at high temperature. the newton’s second law of motion was adapted for translational and rotational motion of particles and agglomerates. the cohesive force for polyethylene particles...

We calculate the cosmic microwave background (CMB) anisotropy spectrum in models with millicharged particles of electric charge q ∼ 10−6 − 10−1 in units of electron charge. We find that a large region of the parameter space for the millicharged particles exists where their effect on the CMB spectrum is similar to the effect of baryons. Using WMAP data on the CMB anisotropy and assuming Big Bang...

effect of temperature on hydrodynamics of bubbling gas-solid fluidized beds was investigated.  experiments were carried out in the range of 25-600 ºc and different superficial gas velocities in the range of 0.17-0.78 m/s with sand particles. time-position trajectory of particles was obtained by radioactive particle tracking technique. these data were used for determination of mean velocities of...

the present study concentrates on the synthesis of au nanoparticles (aunps) using aqueous solution of polyvinylpyrrolidone (pvp) and tetrachloroaurate by different methods as thermal, sonochemical and electrochemical reduction. the pvp has been used as a reducing agent and acts as a stabilizer for au nano particles that obtained as principal product. in all synthesis procedures, the active radi...

In this paper a two impinging streams cyclone contacting system suitable for handling of solid-liquid systems has been studied. Certain pertinent parameters such as: solid holdup, mean residence time and Residence Time Distribution (RTD) of solid particles have been investigated. A stochastic model based on Markov chains processes has been applied which describe the behavior of solid partic...

In this study electrical discharge process was used to increase surface wear resistance of pure aluminum. Pulse-on-time and pulse current were considered as input parameters of the electrical discharge process. Experimental results reveal that the electrical discharge process is a successful method for improving the surface wear resistance of aluminum, so that this method has greatly increased ...

The experimental parameters that control the size and size distribution of dysprosium oxide nanoparticles synthesized by homogeneous precipitation technique have been systematically investigated. The particles were characterized with respect to their size, shape, and thermal decomposition behavior. It was found that the precipitated particles were spherical, uniform in size, and amorphous, whic...

During high velocity oxy-fuel (HVOF) thermal spraying, most powder particles remain in solid state prior to the formation of coating. A finite element (FE) model is developed to study the impact of thermally sprayed solid particles on substrates and to establish the critical particle impact parameters needed for adequate bonding. The particles are given the properties of widely usedWC-Co powder...

The purpose of this study is to identify parameters influence on the particle deposition within fin and tube heat exchanger of air-conditioning systems by CFD analysis. First the basic sketch of periodic geometry drawn and meshing operation including boundary conditions was performed. Then the gas side properties and flow parameters were solved by ANSYS Fluent 14.5 software. Lagrangian equa...