Behavioral effects of a lesion in the ventral mesencephalic tegmentum: evidence for involvement of A10 dopaminergic neurons.

Abstract

Trapped air pockets may cause severe operational problems in hydropower\nand water supply systems. A locally isolated air pocket creates distinct\namplitude, shape and timing of pressure pulses. This paper investigates\ndynamic behaviour of a single trapped air pocket. The air pocket is\nincorporated as a boundary condition into the discrete gas cavity model\n(DGCM). DGCM allows small gas cavities to form at computational sections\nin the method of characteristics (MOC). The growth of the pocket and gas\ncavities is described by the water hammer compatibility equation(s), the\ncontinuity equation for the cavity volume, and the equation of state of\nan ideal gas. Isentropic behaviour is assumed for the trapped gas pocket\nand an isothermal bath for small gas cavities. Experimental\ninvestigations have been performed in a laboratory pipeline apparatus.\nThe apparatus consists of an upstream end high-pressure tank, a\nhorizontal steel pipeline (total length 55.37 m, inner diameter 18 mm),\nfour valve units positioned along the pipeline including the end points,\nand a downstream end tank. A trapped air pocket is captured between two\nball valves at the downstream end of the pipeline. The transient event\nis initiated by rapid opening of the upstream end valve; the downstream\nend valve stays closed during the event. Predicted and measured results\nfor a few typical cases are compared and discussed.