in this study, as for the re-casting, surface alloying and re-solidification layer of this alloys at the work piece level machining with wire electro discharge machining (wedm), changes of surface micro hardness with changes of operational parameters has been studied. therefore, study shows using surface alloying phenomena with the diffusion of wire material into the machined surface and select...

Late in the gaseous phase of a protostellar disk, centimeter-sized bodies probably settle into a thin “dust layer” at the midplane. A velocity difference between the dust layer and the gas gives rise to turbulence, which prevents further settling and direct gravitational instability of the layer. The associated drag on the surface of the layer causes orbital decay in a few thousand years—as opp...

The through-plane permeability of the gas diffusion media (GDM) is investigated experimentally with regard to microporous layer (MPL) composition and (GDL) structure. MPL held constant at 80% carbon powder 20% polytetrafluorethylene (PTFE) (by weight) for various loadings. decrease or increase in GDM was found be dependent on structure GDL used conjunction type powder. It that low-surface-area ...

this study was performed to design bilayer regioselective floating tablets of atenolol and lovastatin to give immediate release of lovastatin and sustained release of atenolol. bilayer floating tablets comprised two layers, i.e immediate release and controlled release layers. the immediate release layer comprised sodium starch glycollate as a super disintegrant and the sustained release layer c...

The objective of this work is to develop deep theoretical methods that are based on the solution of the integral boundary layer equations for investigating film cooling in liquid rocket engine. The integral model assumes that heat is transferred from hot free stream gas to the liquid film both by convection and radiation. The mass is transferred to the free srteam gas by the well-known blowing ...

In flows of granular material, collisions between individual particles result in the movement of particles in directions transverse to the bulk motion. If the particles were distinguishable, a macroscopic overview of the transverse motions of the particles would resemble a self-diffusion of molecules as occurs in a gas. The present granularflow study includes measurements of the self-diffusion ...

In the present work, B-ZSM-5 zeolite membranes were synthesized on porous tubular α-alumina supports by several subsequence in situ crystallization hydrothermal treatments. The TiO2- Bohmite and ɣ- alumina intermediate layers were applied to improve the lattice matching between zeolite layer and the support. The uniform membrane intermediate layers with low permeation resistance were...

We study the morphological stability of layer growth by chemical vapor deposition onto a nonplanar substrate patterned with a facetted groove. Our analytic treatment indicates that, except under conditions of very modest supersaturation, diffusion effects in the gas phase generally preclude the stable growth of crystallographic facets that form the sidewalls of the groove. Instead, heterogeneou...

The conventional gas diffusion layer (GDL) of polymer electrolyte membrane (PEM) fuel cells incorporates a carbon-based substrate, which suffers from electrochemical oxidation as well as mechanical degradation, resulting in reduced durability and performance. In addition, it involves a complex manufacturing process to produce it. The proposed technique aims to resolve both these issues by an ad...

Water appears as a byproduct during normal operation of Proton Exchange Membrane Fuel Cell (PEMFC), and stagnates on the gas diffusion layer (GDL) affecting its performance under certain operating conditions. The primary goal of this study was to develop an ex-situ experimental setup to analyze the sidewall interactions and droplet dynamics under controlled gas flow rates. The channel open angl...