Abstract Background Viscoelastic soluble polymeric additives have been used successfully for a long time as drag reducers in pipelines carrying commercial liquids like crude oil. Most of these polymers suffer from irreversible degradation when exposed to high shearing zones valves, elbows, and pumps which reduces, or eliminates, its flow enhancement effect. Insoluble were proven be an effective...

This study aims at achieving highly crystalline and smooth Nitrogen-polar (N-polar) GaN layers deposited on c-plane sapphire by metal organic vapor phase epitaxy (MOVPE). The influence of nitridation, temperature and V/III ratio on the polarity, quality and coalescence of GaN is systematically investigated. It was observed that the initial nitridation of sapphire before GaN growth is critical f...

Reciprocating diaphragm micro-pumps are the most common type among indirectly–driven micro-pumps. They operate by reciprocating the diaphragm with associated check valves. This paper addresses the Hydroelastic vibration of circular elastic diaphragm interacting with the incompressible and inviscid liquid inside the cylindrical chamber with a central discharge opening. Taking into account axisym...

At what characteristic length scale does classical continuum elasticity cease to accurately describe small deformation mechanical behavior? The two dominant physical mechanisms that lead to size dependency of elastic behavior at the nanoscale are surface energy effects and nonlocal interactions. The latter arises due to the discrete structure of matter and the fluctuations in the interatomic fo...

We develop a combined field formulation for the fluid structure (FS) interaction problem. The unknowns are (u; p;v), being the fluid velocity, fluid pressure and solid velocity. This combined field formulation uses Arbitrary Lagrangian Eulerian (ALE) description for the fluid and Lagrangian description for the solid. It automatically enforces the simultaneous continuities of both velocity and t...

The measurement of the saddle-splay surface elastic constant K~4 in a nernatic liquid crystal is reported based on two independent deuterium nuclear-magnetic-resonance (H-NMR) experiments. Fifty years after the pioneering work of Oseen and Zocher, these measurements were made from observations of nematic director-field configurations and a configuration transition discovered in submicrometer-si...

in this study; utilizing the elastic matrix ball has higher processing efficiency and better superficial quality than traditionalgrinding. the diversity of elastic abrasive tool characteristics contact with bend surface results in irregular wear abrasion，and abrasive tool machining status gets complicated. there is no theoretical interpretation of parameters affecting the grinding accuracy. bec...

candesartan cilexetil (cc) is a newer class of angiotensin ii receptor antagonist used for the treatment of hypertension. the solubility of the cc is very poor and its oral bioavailability is only 15%. the controlled-release polar lipid microparticles of cc (formulations f1, f2, f3 and f4) were prepared using variable erodible lipophilic excipients like hydrogenated castor oil, stearic acid, ce...