Oil field is a very important non-renewable resource in China, which plays role economic strategy. In the process of oil development, water flooding technology can effectively improve production quality, provide strong technical support for our exploitation, and help to promote sustainable development enterprises. However, there are many influencing factors exploitation oilfield, so workers nee...

the simultaneous flow of oil and water in porous media is described by relative permeability curves, mainly derived from laboratory experiments. relative permeability is of paramount importance in predicting reservoir production performance and drive mechanisms and its value depends largely on the volume fraction of fluids present in the test samples. nowadays x-ray scanners are one of the most...

We studied the effects of water vapor on the efficiencies of resistive plate chambers with glass electrodes, operated in the streamer mode. With moisture in the chamber gas that has freon as a component (water vapor B1000 ppm), a decrease in the efficiency (B20%) has been observed after operating for a period of several weeks to a few months. From our study, the cause of the efficiency decrease...

In this paper, a new method is proposed for the speed control of a three-phase current forced synchronous machine drive. This metohd is based on the use of an approximate constant commutation safety margin angle in the output thyristor bridge of the drive system as well as on the compenastion of stator magnetization reaction. The commutation process in the output converter of the machine driv...

In this paper, using a personal computer (PC), the practical implementation of scalar and vector control methods on a three–phase rotor surface- type permanent magnet synchronous machine drive is discussed. Based on the machine dynamic equations and the above control strategies, two block diagrams are presented first for closed-loop speed controlling of the machine drive/system. Then, the desig...

in this paper, the finite element analysis of stability problem of vehicle composite drive shafts subjected to torsional loading is studied. first, using the minimum total potential energy principle, the governing equations are derived and then they are solved by finite element method. the initial geometrical imperfection which is usually in the form of radial displacement, is taken into consid...