Pump action

The principle of operation of the hydraulic reciprocating pump is similar to the beam pump, with a piston-like sub-surface pump action. The energy to drive the pump, however, is delivered through a hydraulic medium, the power fluid, commonly oil or water. The power fluid drives a downhole hydraulic motor which in turn drives the pump. A separate surface pump delivers the hydraulic power. The power fluid system can be of the closed loop or of the open type. In the latter case, the power fluids are mixed with the produced fluid stream. The performance of the hydraulic pump is primarily monitored by measuring the discharge pressures of both surface and sub-surface pumps. 

The pumping action of the heart rather than gravity is responsible for blood flow hence the term pgl can be set equal to zero in Eq. (9.29) and the result solved for 77 ... 

One of the remarkable features of the heart, which is about the size of a fist, is that the pumping action or contractions (- 70 times/min) of atria and ventricles are simultaneous. Deoxygenated blood is pumped out to the lungs from one side of the heart at the same time oxygenated blood is pumped out from the other side to the aorta and onward through the body. The entire process of blood flow between the atria, ventricles, and the principal vessels is in unison, controlled in part by four one-way valves. The atrioventricular valves, tricuspid on the right and mitral on the left, prevent blood from flowing... 

Products with dissolved gas must be properly vented. In most cases, vent the stuffing box back to pump action. 

In unloaded or part-load operation, rod reversals must be of sufficient magnitude to provide lubrication to the crosshead bearings. The bearings are lubricated by the pumping action of the opening and closing of the bearing clearance area. 

Twin-screw extruders now dominate the extrusion field, particularly because of their positive pumping action which is so important with PVC in powder form. 

Bacharach smoke scale A scale of 10 shades of white to black for a smoke stain formed in a prescribed manner by a pumping action through a filter paper, used for the assessment of smoke from combustion appliances. 

The discovery of the antiulcer activity of H2 antihistamine antagonists has revolutionized the treatment of that disease. A benzimidazole. Omeprazole (55), inhibits gastric secretion and subsequent ulcer formation by a quite different mechanism. Studies at the molecular level suggest that this compound inhibits K /H dependent ATPase and consequently shuts down the proton pumping action of this enzyme system. 

Running liquid ring eccentric and causing pumping action on air... 

The most prominent expression of cardiac activity is the rhythmical contraction of the heart - its pumping action. Less well known is the fact, that this mechanical activity is tightly controlled by an electrical process called excitation. ... 

P 68] No detailed experimental protocol was given [61, 62,142,143]. Two reactant streams, the solution of the reactant in hexane and concentrated sulfuric acid, were fed separately in a specially designed micro reactor by pumping action. There, a bilayer was formed initially, potentially decomposed to a dispersion, and led to rapid mass transfer between the phases. From this point, temperature was controlled by counter-flow heat exchange between the reaction channel and surrounding heat-transfer channel. The reaction was typically carried out at temperatures from 0 to 50 °C and using residence times of only a few seconds. If needed, a delay loop of... 

Body temperature also affects heart rate by altering the rate of discharge of the SA node. An increase of 1°F in body temperature results in an increase in heart rate of about 10 beats per minute. Therefore, the increase in body temperature during a fever or that which accompanies exercise serves to increase heart rate and, as a result, cardiac output. This enhanced pumping action of the heart delivers more blood to the tissues and supports the increased metabolic activity associated with these conditions. 

Lymphatic capillaries join together to form larger lymphatic vessels that have valves within them to ensure the one-way flow of lymph. The lymph is moved along by two mechanisms. Automatic, rhythmic waves of contraction of the smooth muscle in the walls of these vessels are the primary mechanism by which lymph is propelled through the system. Second, the contraction of skeletal muscles causes compression of lymphatic vessels. As in the veins, this pumping action of the surrounding skeletal muscles contributes to movement of the lymph. Ultimately, the lymph is returned to the blood when it empties into the subclavian and jugular veins near the heart. 

The pump action is usually defined in terms of a pumping speed S ... 

The pumping action is due to a high-speed rotating surface that transfers momentum to the gas molecules (see Fig. 1.16). 

Movement of solution away from the disc in this way would cause a vacuum to form at the disc centre, and so more solution is drawn in, from the solution bulk towards the electrode face. In effect, the rotation of the disc induces a sort of pump action, with solution continually being drawn from the bulk, travelling toward the surface of the disc electrode, over the disc and hence back into the solution bulk. It is this pump action that we follow as the flux of analyte solution at the RDE. 

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