The name Minneapolis is attributed to Charles Hoag, the city's first schoolteacher, who combined mni, a Dakota Sioux word for water, and polis, the Greek word for city.
EGR valve on top of the inlet manifold of a Saab H engine in a 1987 Saab 90. In internal combustion engines, exhaust gas recirculation (EGR) is a nitrogen oxide (NOx) emissions reduction technique used in petrol/gasoline and diesel engines. EGR works by recirculating a portion of an engine's exhaust gas back to the engine cylinders.
An exhaust system is usually piping used to guide reaction exhaust gases away from a controlled combustion inside an engine or stove. 1  The entire system conveys burnt gases from the engine and includes one or more exhaust pipes. Depending on the overall system design, the exhaust gas may flow through one or more of: 1  Cylinder head and exhaust manifold. 2  A turbocharger to increase engine power. 3  A catalytic converter to reduce air pollution. 4  A muffler (North America) / silencer (UK/India), to reduce noise.