REVERSE OSMOSIS(R.O)

Reverse osmosis is a liquid filtration method which removes many types of large atomic molecules from smaller molecules by forcing the liquid at high pressure through a membrane with pores (holes) just big enough to allow the small molecules to pass through.

It is most commonly known for its use in drinking water purification from seawater, removing the salt and other substances from the water molecules. However, the process is also used for filtering many other types of liquids.

The process is similar to membrane filtration. However there are key differences between reverse osmosis and filtration. The predominant removal mechanism in membrane filtration is straining, or size exclusion, so the process can theoretically achieve perfect exclusion of particles regardless of operational parameters such as influent pressure and concentration. RO (Reverse Osmosis), however involves a diffusive mechanism so that separation efficiency is dependent on influent solute concentration, pressure and water flux rate. It works by using pressure to force a solution through a membrane, retaining the solute on one side and allowing the pure solvent to pass to the other side. This is the reverse of the normal osmosis process, which is the natural movement of solvent from an area of low solute concentration, through a membrane, to an area of high solute concentration when no external pressure is applied.

RUSSIA TO BE FIRST TO BUILD NUCLEAR-POWERED SPACECRAFT

 Russia will endeavour to become the world’s first nation to build a nuclear-powered spacecraft for interplanetary flights.

 The draft design of the spacecraft is slated to be ready by 2012, while the actual model is expected to be developed by 2018. The total cost of the project is estimated at about $600 million.

 Nuclear powered spacecraft are essential for space travels far from the sun, where getting power from solar energy becomes problematic, and to planets like Mars.

 Russia has a unique half-a-century experience in developing and operating n-power reactors in space. the Soviet Union launched a total of 32 spacecraft with small-capacity nuclear propulsion units in the 1970s and 1980s. By comparison, the United States had only one such craft with a nuclear-reactor launched in 1965.