Synthesis of nanostructured materials

Nanotechnology and nanomaterials are now interesting subjects of mankind. Generally any material whose dimension ranges 0.1 to 100 nm is called as nanomaterials. Quantum dots are zero dimensional, multilayers (Quantum wire) are one dimensional, ultrafine grained over layers or buried layers (Quantum well) are two dimensional equiaxed nanometer sized grains are three dimensional nanomaterials. There exist two steps for the synthesis of nanostructured materials- top-down and bottom-up. Examples of top-down methods are mechanical alloying or milling, lithography and erosion. Examples for bottom-up methods are chemical coprecipitation, gas phase agglomeration, sol gel, reverse micelles, physical and chemical vapour deposition, sputtering and self assembly. 

Hydroelectric power plant

Hydroelectric power plant can be used for many purposes like electrical power generation, controlling of floods, storing of irrigation water and storing of drinking water. The main advantage of hydroelectric power plant compared to other power plants is that fuel is not required here. A hydroelectric power plant remains very neat and clean always. Operational and maintenance cost is very less. Rapid load variation possible here with a longer life span. Highly skilled engineers are not an essential requirement here. There are no standby losses in hydroelectric power plants. We can easily maintain constant speed and frequency. But construction cost is very high. It takes more time for installation. Long transmission lines are required and we have to depend on monsoon. It consumes large area. The main components of a hydroelectric plant are generator, switchgear, transmission lines, catchment area, reservoir, dam and head works, sluice gate or valve, penstock, inlet valve, turbine and tail race.