Backpressure effects

To compensate for backpressure effects, the effective area of the bellows must be the same as the nozzle seat area. This prevents backpressure from acting on the top area of the disc, which is not pressure-balanced, and cancels the effects of backpressure on the disc. This results in a stable set pressure (Figure 5.16). 

Effect of backpressure on the lift of an SRV Backpressure effects on perfect nozzle... 

During a turnover cycle of the pump, nCa calcium ions and wH protons are transported across the membrane per mole of ATP molecule. Therefore, nca and nH represent Ca2+/ATP and H+/ATP coupling stoichiometries, respectively, while n/ r i represents the H+/Ca2+ stoichiometry. Experimental observations show that both A/ICa and A/IH can inhibit. /p by exerting a backpressure effect on the rate of ATP hydrolysis for the plasma membranes. Therefore, the actual total thermodynamic force Ap may be... 

It is not surprising that fluids can be propelled by gravity [45], which provides a pulseless flow. The flow rate is highly dependent on backpressure effects that are difficult to control due to variations in temperature and fluid viscosity. Such systems are simple, inexpensive and do not contain any moving parts, leading to minimal implementation and... 

Leaks, backpressure, and actuator dynamics all influence the performance of peristaltic pumps. Leaks and backpressure effects will alter the distribution of fluid as actuators open and close. The dynamics of the actuators determines the maximum actuation rate, which in turn limits the maximum flow rate. These effects can be incorporated into lumped-parameter models for analysis and simulation. We do not pursue this further in this article, but refer the reader to the literature. One general approach is presented in [5]. Also relevant for further study are [6], [13] and [14], which present dynamic models for pneumatic and electrostatic pumps, respectively. All of these works are applied to liquid pumps. For gas pumps, or robustness to bubbles, compressibility becomes a factor. Some considerations of micropumps for compressible fluids may be found in [1]. Finite-element analysis of individual chambers can also be used to obtain detailed predictions of puiiq) dynamic performance. 

Samples were usually transferred to the microfluidic system by electrokinetic injection and pressure injection. Electrokinetic sample introduction is most commonly used for transferring samples to chips. This can be attributed to factors such as the simpUcity in achieving electroosmotic flow (EOF), i. e., no moving parts and minimal backpressure effects. The EOF in the microchan-nel acts as a pump and can easily be controlled by outside high voltages. The two commonly employed injection modes for microfluidic chips are time-based and discrete volume-based injection. In the case of the time-based (or gated injection), the amount of sample introduced into the carrier stream can be controlled by adjusting the injection time. 

With 0/E values being so similar for the two phases, it would seem that the differential pond setting is optimum, barring any cresting effects or backpressure effects from any discharge device. If it were necessary, say, to Improve the quality of the oil phase at the expense of water effluent quality, then the water discharge diameter would need to be increased very slightly, to increase the depth of the oil level in the pond. 

THEORETICAL AND SEMIEMPIRICAL ANALYSIS OF BACKPRESSURE EFFECTS ON FUEL CELL PERFORMANCE... 

Backpressure Effect on Fuel Cell Kinetics (Electrode Kinetics and Mass Transfer Process)... 

Backpressure Effect on Overall Fuel Cell Performance [18-21]... 

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