The first stage to have access to a reservoir is the drilling operation. The proper development of this operation plays a major role in increasing productivity. It must be pointed out that the drilling fluid (mud) is pivotal in achieving this objective. Among these fluids, water-based fluids are the most common ones, which have been utilized to drill approximately 80% of all wells and are m...

BACKGROUND The present study aimed to explore the relationship between surgical methods, hemorrhage position, hemorrhage volume, surgical timing and treatment outcome of hypertensive intracerebral hemorrhage (HICH). METHODS A total of 1 310 patients, who had been admitted to six hospitals from January 2004 to January 2008, were divided into six groups according to different surgical methods: ...

Composite materials are widely employed in the naval, aerospace and transportation industries owing to the combination of being lightweight and having a high modulus of elasticity, strength and stiffness. Drilling is an operation generally used in composite materials to assemble the final product. Damages such as the burr at the drill entrance and exit, geometric deviations and delamination are...

The vibration phenomenon represents the cause of many problems in metal cutting processes. It has a big influence on the quality of the machining operation, tool life and machine precision. Drilling operation is a common metal cutting process where quality of the hole form is often a critical issue. Therefore, it was necessary to predict these vibrations. The first part of this paper deals with...