This paper proposes an improved control method based on modified Delta-Sigma Modulator (DSM) to enhance transient response and improve harmonic contents of buck DC-DC converter. The main advantages of the proposed method are improving the output voltage frequency spectrum, correction of the output voltage harmonic contents and sideband harmonics, reduction of switching noise peaks at the output...

a simple method is described for analysis of transients in power network. the method is developed for analysis of transformer and generator winding resonances due to their interaction with transmission lines caused by switching surges. the method is already used for calculation of overvoltages which had resulted in damages in the transformer winding of a hydro power plant. nonlinearity in the i...

The purpose of this paper is to analyze the flow field structure in transient state and performance of secondary injection system for thrust vectoring in divergent section of a two-dimensional nozzle. Secondary injection for thrust vectoring in a two-dimensional nozzle is studied by solving three-dimensional Reynolds-averaged equations by means of fluent solver. Spalart-allmaras model was used ...

In the present study, the transient stress distribution caused by a break in the fibers of an adhesive bonding is investigated. Transient stress is a dynamic response of the system to any discontinuity in the fibers from detachment time till their equilibrium state (or steady state). To derive the governing dynamic equilibrium equations shear lag model is used. Here, it is assumed that the tens...

Background. Non-alcoholic fatty liver disease (NAFLD) is the most common chronic disease. In recent years, disorders in hemostasis system, their role progression of diseases and development cardiovascular complications NAFLD have been actively studied. The purpose was to investigate features system patients with non-alcoholic Materials methods. We examined 36 individuals (20 women 16 men) aged ...

Liver fibrosis is critical for liver-related outcomes and mortality in chronic liver disease, irrespective of etiology, including nonalcoholic fatty disease (NAFLD). NAFLD has been viewed as an independent correlate cardiovascular risk. This review article briefly describes the cellular molecular pathomechanisms underlying hepatic fibrosis. We then address noninvasive assessment Finally, we dis...

In this paper we have studied the effect of free convection on the heat transfer and flow through variable porous medium which is bounded by two vertical parallel porous plates. In this study it is assume that free stream velocity oscillates with time about a constant mean. Periodic temperature is considered in the moving plate. Effect of different parameters on mean flow velocity, Transient ve...

This paper deals with the transient analysis of K-out-of-N: G system consisting of Noperatingmachines. To improve system reliability, Y cold standby and S warm standbys spares areprovided to replace the failed machines. The machines are assumed to fail in multiple modes. At leastK-out-of-N machines for smooth functioning of the system. Reliability and mean time to failure areestablished in term...