Plasma immersion ion implantation (PIII) into gearywindmill structures is simulated by the particle-in-cell (PIC) method in cylindrical co-ordinates. In cylindrical co-ordinates, the gearywindmill geometry becomes a periodic regular structure. An equal number of particles are placed inside the cell with the same angular and radial distance. The ion density represented by each particle is obtain...

in this study, a pellet scale model was developed for trickle bed reactor utilizing cfd techniques. drag coefficients were calculated numerically at different velocities and bulk porosities in the case of single phase flow through the dry bed. the simulation results were then compared with the prediction of kozeny-carman (k-c) equation. the results indicated that drag coefficients calculated fr...

An Eulerian model (convection–diffusion– migration equation) to evaluate particle transport in patchy heterogeneous cylindrical microchannels is presented. The objective of this model is to capture the effect of surface chemical heterogeneity on deposition and particle transport in cylindrical microchannels with fully developed Poiseuille flow velocity profile. Surface heterogeneity is modeled ...

the effect of geometry and material of the micro/nano particle on contact mechanic for manipulation was studied in this work based on atomic force microscopy. hertz contact model simulation for eph biological micro particle with spherical, cylindrical, and circular crowned roller shape was used to investigate the effect of geometry on contact simulation process in manipulation. then, to validat...

The Inönü-Wigner contraction is applied to special relativity and the little groups of the Lorentz group. If the O(3) symmetry group for massive particle is boosted to an infinite-momentum frame, it becomes contracted to a combination of the cylindrical group and the two-dimensional Euclidean group. The Euclidean component becomes the Lorentz condition applicable to the electromagnetic four-pot...

Previous experimental studies of anisotropy and non-coaxiality by using the hollow cylindrical apparatus are mainly focused on granular soils, which feature irregular particle shapes and non-uniform particle size distributions. This paper experimentally investigates these two characteristics on assemblages of particulate materials with regular particle shapes and uniform particle sizes. These a...

Digital in-line holography is used to visualize particle motion within a cylindrical micropipe. Analytical expression of the intensity distribution recorded in the CCD sensor plane is derived using the generalized Huygens-Fresnel integral associated with the ABCD matrices formalism. Holograms obtained in a 100microm in diameter micropipe are then reconstructed using fractional Fourier transform...

We develop the theory of transient electrophoresis a weakly charged, infinitely long cylindrical colloidal particle under an application transverse or tangential step electric field. Transient electrophoretic mobility approaches steady with time. derive closed-form expressions for cylinder without involving numerical inverse Laplace transformations and corresponding time-dependent Henry functio...

Composite stiffened cylindrical shells are widely used as primary elements in aerospace structures. In the recent years, there has been a growing research interest in optimum design of composite stiffened cylindrical shell structures for stability under buckling load.  This paper focuses upon the development of an efficient optimization of ring-stringer stiffened cylindrical shell. The opti...