A tutorial paper with a review of the technologies available in the mid-eighties for surge protection of lowvoltage end-user equipment. The principles of operation are described for “crowbar devices” (now generally described under the standardized name of “voltage switching devices”) and for “voltage clamping devices: (now generally described under the standardized name of “voltage limiting dev...

the reaction of ch3o2 radicals with acetaldehyde on the solid surface of nh4no3 has been studied in a flow capillary reactor at low pressure and room temperature. the experiments were performed using epr spectrometer combined with the kinetic method of radicals freezing. peroxy radicals revealed an oscillation complex behavior during the process regarding to the phenomenon of radicals multiplic...

In the aftermath of a natural catastrophe there is an increased demand for skilled reconstruction labor, which leads to significant increases of reconstruction labor wages and hence insured losses. Such inflation effects are referred to as "Demand Surge" effects. It is important for insurance companies to properly account for these effects when calculating insurance premiums and determining the...

The preovulatory GnRH/LH surge in the ewe is stimulated by a rise in the circulating estradiol concentration that occurs in conjunction with preovulatory ovarian follicle development. In the presence of high levels of progesterone, such as during the luteal phase of the estrous/menstrual cycle, the stimulatory effects of elevated estradiol on GnRH/LH secretion are blocked. Recent work in the ew...

Control and Modeling for stall and surge phenomenon in axial flow compressors have received great importance in recent times. In power generation plant and aerospace propulsion compression system are prone to the aerodynamic instabilities of stall and surge. In aero engine compressors higher pressure ratio has always been a growing stipulates which has over involved by diverse rotating stall an...

We investigated the relationship between the day-night blood pressure (BP) dip and the early morning BP surge in an cohort of 3012 initially untreated subjects with essential hypertension. The day-night reduction in systolic BP showed a direct association with the sleep trough (r = 0.564; P < 0.0001) and the preawakening (r = 0.554; P < 0.0001) systolic BP surge. Over a mean follow-up period of...

The objective of this paper is to examine the effectiveness of wall oscillation as a control scheme of drag reduction. Two flow configurations are considered: constant flow rate and constant mean pressure gradient. The Navier-Stokes equations are solved using Fourier-Chebyshev spectral methods and the oscillation in sinusoidal form is enforced on the walls through boundary conditions for the sp...

Surge protective device is a part of internal lightning protection and it crucially to divert the certain amount of surges to the ground before the protected load able to handle. Therefore, this paper studying the enhancement of SPD through the effect of adding a filter in hybrid surge protection circuit using simulation modeling. Ordinarily, filter is used as in eliminating noises in certain a...