We have tested the applicability of the global modal approach in the density wave theory of spiral structure for a sample of six spiral galaxies: NGC 488, NGC 628, NGC 1566, NGC 2985, NGC 3938 and NGC 6503. The galaxies demonstrate a variety of spiral patterns from the regular open and tightly wound spiral patterns to a multi-armed spiral structure. Using the observed radial distributions of th...

the effect of membrane molecular weight cut off (mwco) at three levels (10, 20 & 50 kd) on dynamic behavior of permeate flux (jp), hydraulic resistances (total hydraulic resistance, rt; reversible fouling resistance, rrf; irreversible fouling resistance, rif and membrane hydraulic resistance, rm) and milk solutes rejection (protein, rp; fat, rf; lactose, rl; minerals, rm and total solids, r...

background: chromium (cr) is the most important element used to plate other metals and electroplating factories are still consid­ered to be the most important industries which pollute the environment to this metal. this paper describes a study con­ducted to determine the efficiency of reverse-osmosis (ro) as a membrane technique for removal of cr from wastewater sam­ples synthetically prepared ...

National Institute for Occupational Safety and Health (NIOSH) researchers continue to study the potential for lithium and lithium-ion battery thermal runaway from an internal short circuit in equipment for use in underground coal mines. Researchers conducted cell crush tests using a plastic wedge within a 20-L explosion-containment chamber filled with 6.5% CH4-air to simulate the mining hazard....

The effect of membrane molecular weight cut off (MWCO) at three levels (10, 20 & 50 kD) on dynamic behavior of permeate flux (JP), hydraulic resistances (total hydraulic resistance, RT; reversible fouling resistance, Rrf; irreversible fouling resistance, Rif and membrane hydraulic resistance, Rm) and milk solutes rejection (protein, R<s...