A wind driven electricity generator may have a tower with a set of stationary airfoils mounted thereon. Each airfoil may have a slot on a low pressure side of the airfoil. Air flow may through the slot relative to an inside of the airfoil. Air flowing through the airfoil may flow through the tower. The air flowing through the tower may turn a rotor (or propeller). The rotor may turn an electrical generator to generate electricity. Each airfoil may have a slot on a high pressure side. Air flowing through the slot on the high pressure side may turn the rotor.

A fluid connection for a hydromotive machine or fluid-control valve having a first duct and a second duct. The first duct includes a mid-portion between a first end of the first duct and a second end of the first duct that has a non-circular cross-section. A second end of the first duct is wholly within the second end of the second duct. A first end of the second duct is wholly outside of the first duct.

A fluid connection for a hydromotive machine or fluid-control valve having a first duct and a second duct. The first duct includes a mid-portion between a first end of the first duct and a second end of the first duct that has a non-circular cross-section. A second end of the first duct is wholly within the second end of the second duct. A first end of the second duct is wholly outside of the first duct.