seismic base isolation are devices that used to limit the human and material damage caused by an earthquake. this devices diffuse the energy induced at the time of the earthquake before being transferred to the structure.the base isolated structures when subjected to the near-fault eathquakes which contain long-period velocity pulses that may coincide with the period of base isolated structures...

in the present study, an investigation was carried out on parvadeh coal mine in tabas, iran, to survey the effect of fractures on unusual methane gas emission in coal mines. this coal mine was chosen for investigating because of its high methane gas content in the coal body and available data from sensors in desired locations. gas concentration monitoring programs were carried out at the mine s...

Sintered metal porous media currently plays an important role in air bearing systems. When flowing through porous media, the flow properties are generally represented by incompressible Darcy-Forchheimer regime or Ergun regime. In this study, a modified Ergun equation, which includes air compressibility effects, is developed to describe friction characteristic. Experimental and theoretical inves...

At impact of a liquid drop on a solid surface, an air bubble can be entrapped. Here, we show that two competing effects minimize the (relative) size of this entrained air bubble: for large drop impact velocity and large droplets, the inertia of the liquid flattens the entrained bubble, whereas for small impact velocity and small droplets, capillary forces minimize the entrained bubble. However,...

A boron-modified molybdenum silicide material having the composition comprising about 80 to about 90 weight % Mo, about 10 to about 20 weight % Si, and about 0.1 to about 2 weight % B and a multiphase microstructure including Mo.sub.5 Si.sub.3 phase as at least one microstructural component effective to impart good high temperature creep resistance. The boron-modified molybdenum silicide materi...

Compressed Air Energy Storage (CAES) is a process for storing and delivering energy as electricity. A CAES facility consists of an electric generation system and an energy storage system. Only earth based geological structures can currently store adequate potential energy in the form of a pressurized air mass required by commercial electric turbines. Earth based structures suitable for service ...

This article presents an experimental study carried out on a rotor operating two foil bearings. One of the bearings was built in way to measure temperature and deformation top bearing. The dynamic performance bearing journals is presented herein using vibration trajectories journal positions sleeve. Based these results, method for predicting distribution developed. Then, correlations between pa...

In the present study, an investigation was carried out on Parvadeh coal mine in Tabas, Iran, to survey the effect of fractures on unusual methane gas emission in coal mines. This coal mine was chosen for investigating because of its high methane gas content in the coal body and available data from sensors in desired locations. Gas concentration monitoring programs were carried out at the mine s...

OBJECTIVE To investigate the diagnostic value of different patient positions during expiratory low-dose thin-layer multidetector computed tomography (MDCT) for detecting air trapping after allogeneic hematopoietic stem cell transplantation (allo-HSCT). PATIENTS AND METHODS Expiratory lung MDCT scanning was done for 51 post-allo-HSCT patients in both the supine and prone positions to determine...