BACKGROUND Avascular necrosis of femoral head (AVNFH) typically presents in the young adults and progresses quickly without proper treatments. However, the optimum treatments for early stage of AVNFH are still controversial. This study was conducted to evaluate the therapeutic effects of multiple small-diameter drilling decompression combined with hip arthroscopy for early AVNFH compared to dri...

The growth of Indian manufacturing sector depends largely on its productivity & quality. Productivity can be improved by reducing the total machining time, combining the operations etc. In case of mass production where variety of jobs is less and quantity to be produced is huge, it is very essential to produce the job at a faster rate. This is not possible if we carry out the production by usin...

Composites are more and more increasing their importance as one of the most interesting group of materials, because of their unique properties. Hole drilling operations are common in composite parts to facilitate fastener assembly. As composites are non-homogeneous this operation causes some damages like delamination and others that reduce bearing and fatigue strength of the composite part. A p...

Drilling is the most frequently employed operation of secondary machining for fiber-reinforced materials owing to the need for structure joining. Delamination is one of the serious concerns during drilling. Practical experience shows that an eccentric twist drill or an eccentric candle stick drill can degrade the quality of the fiber reinforced material. Comprehensive delamination models for th...

The data measured by well bottom sensors can be transmitted to the surface through the drilling mud during oil drilling operations. This article introduces a data processing scheme for a wireless data transmission application via mud. The detailed signal processing procedure is given, and several data processing techniques used are discussed, mainly including data encoding and signal integratin...

drilling operations are exposed to a variety of hazards, some of which may be location and activity dependent and each could pose different risk from different paths.  drilling operation may be vulnerable to hurricanes in one region and be exposed to geohazards in another. however, there are other hazards, (e.g. corrosion, age degradation, poor maintenance), which equally affects every rig. ide...

The oil and gas industry plays a vital role in meeting the ever-growing energy demand of human race needed for its sustainable existence. Newer unconventional wells are drilled extraction hydrocarbons that requires advanced innovations to encounter challenges associated with drilling operations. type drill bits utilized any operation has an economical influence on overall operation. selection s...

We present a drilling method that is based on the phenomenon of local hot spot generation by near-field microwave radiation. The microwave drill is implemented by a coaxial near-field radiator fed by a conventional microwave source. The near-field radiator induces the microwave energy into a small volume in the drilled material under its surface, and a hot spot evolves in a rapid thermal-runawa...

The paper describes a novel method of drilling into hard non-conductive materials by localized microwave energy (US patent 6,114,676). The Microwave Drill implementation may utilize a conventional 2.45GHz magnetron, to form a portable and relatively simple drilling tool. The drilling head consists of a coaxial guide and a near-field concentrator. The latter focuses the microwave radiation into ...