Tissue size has been considered an important determinant of atrial fibrillation (AF), but recent work has questioned the critical size hypothesis. Here, we use a previously developed mathematical model of the two-dimensional canine atrium with realistic action potential, ionic, and conduction properties to address substrate size effects on the maintenance of fibrillatory activity. Cholinergic A...

For many years the authors have been investigating the use of twin screw machines to fulfil both the expansion and compression. One of potential advantages of screw machines over other types of positive displacement machine is their ability to perform both the compression and expansion functions simultaneously, using only one pair of rotors. A further feature is the use of the rotors which seal...

Due to long life of steam power plants in Iran, transformation of steam cycles to combined cycles is under consideration. Bandar-Abbas steam power plant with capacity of 320 MW has been analyzed in this work. This old plant is located near the harbor city of Bandar-Abbas at southern Iran. Method of exergy analysis is used to study the current and the repowered systems. Optimum state of the repo...

This paper shows how simulation of screw rotor profile manufacturing can be used in the design phase to assess profile alternatives. To do this, variations in manufacturing parameters are studied to illustrate how these deviations affect different rotor profile shapes and the resulting rotor pair clearances. INTRODUCTION Clearances between rotors in a twin screw compressor play a key role in de...

Different problems may cause distortion of the rotor, and hence vibration, which is the most severe damage of the turbine rotors. Different techniques have been developed for the straightening of bent rotors. The method for straightening can be selected according to initial information from preliminary inspections and tests such as nondestructive tests, chemical analysis, run out tests and also...

The present paper investigates the reliability and sensitivity analysis of a coal handling unit of a thermal power plant using a probabilistic approach. Coal handling unit is the main block of a thermal power plant and it is necessary for a good function of a power plant that its power supply, which is dealt in coal handling unit, must function continuously without any obstacle. The configurati...

Renewable energy provides twenty percent of electricity generation worldwide. Hydroelectric power is the cheapest way to generate electricity today. It is a renewable source of energy and provides almost one-fifth of electricity in the world. Also, it generates electricity using a renewable natural resource and accounting for six percent of worldwide energy supply or about fifteen percent of th...