An experimental study was performed to identify the surge inception dynamics and to demonstrate an active surge control on a 600 HP class Allison 250-C30 gas turbine engine. Throttling orifices inserted between the compressor and the combustor were used to move the steady state operating line toward the surge line. The compressor was then adjustably throttled into surge using water injection do...

Based on the proliferation of surge-protective devices in low-voltage end-user installations, the paper draws attention to the need for changing focus from surge voltage measurements to surge current measurements. One proposed approach was to develop a simple transducer measuring the surge current that would be drawn in an SPD with low clamping voltage connected to the circuit to be monitored. ...

Human chorionic gonadotropin (hCG) has been used as a surrogate for the mid-cycle LH surge for several decades. Due to structural and biological similarities with LH, hCG binds to and activates the same receptor - the LH/hCG receptor. However, despite the fact that hCG effectively secures final oocyte maturation and ovulation, its use as a surrogate for LH has got several drawbacks - first and ...

BACKGROUND The association of preawake (difference between pre- and postwaking blood pressure (BP)) and sleep-through surge (difference between sleeping nadir and postwaking BP) with cardiovascular events is unclear. Examination of factors associated with surge may provide novel insights. We examined the association of race, which associates with nocturnal dipping, and plasma renin activity (PR...

To avoid co-surge the mass flows should be kept balanced. Still co-surge can occur when operating close to the surge line due to disturbances between the two mass flows. In that case the control system needs to detect the co-surge oscillation and take proper actions. The simulation model is used to evaluate detection and control algorithms, which are then tested in vehicle. −0.25 0 0.25 0.5 0.7...

Until now, clinicians have been relying solely on LH activity-dependent triggering of final oocyte maturation and thus taken it for granted that the natural midcycle FSH surge is biologically redundant. However, it is time to question this paradigm. Evidence from clinical studies hint that in a yet-to-be-defined subset of patients, dual LH and FSH surge is advantageous compared with LH-only sur...

This paper presents a new analysis of the effects of ambient temperature variations on the surge characteristics of turbo heat pumps. To this end, an analytical model capable of predicting unsteady behavior of surge in turbo heat pumps has been developed. In compression systems, surge is mostly caused by the compressor work exceeding the mechanical inertia of the system. In refrigeration system...

In sheep, the surge mode of gonadotropin secretion is sexually differentiated, i.e. the LH surge is present in the female, but not in the male. The present study tested the hypothesis that sexual differentiation of the LH surge mechanism reflects a sex difference in the pattern of GnRH, and that prenatal androgens abolish the surge mode of GnRH secretion. We monitored the pattern of GnRH secret...