Reed Valves

Technology / Motorcycle / Reed Valves: Reed valves are commonly used in high-performance versions of the two-stroke engine, where they control the fuel-air mixture admitted to the crankcase. As the piston rises in the cylinder the resulting vacuum opens the valve and admits the fuel-air mixture. As the piston descends, it raises the crankcase pressure causing the valve to close to retain the mixture and pressurize it for its eventual transfer through to the combustion chamber

Screed, Plaster

Business / Construction / Screed, Plaster: A small strip of wood, usually the thickness of the plaster coat, used as a guide for plastering. MORE

Screed, Concrete

Business / Construction / Screed, Concrete: To level off concrete to the correct elevation during a concrete pour. MORE

Selective Breeding

Science / Biology / Selective Breeding: The selection of individuals with desirable traits for use in breeding. Over many generations, the practice leads to the development of strains with the desired characteristics. MORE