RATIONALE Retrograde drilling is a well accepted procedure for osteochondral lesion of the talus and subchondral cyst with intact overlying cartilage. It has good results in most reports. Compared to anterograde drilling, retrograde drilling can protect the integrity of the articular cartilage. The purpose of this study was to evaluate the suitability of using retrograde drilling for osteochond...

Drilling of glass fibre reinforced plastic (GFRP) composite is different from metallic materials due to its mechanical properties. The drilling of this material may generate delamination of drilled holes on workpiece. The purpose of this paper is to investigate the influence of the cutting parameters, such as cutting speed and feed rate, point angle of drill and material thickness on delaminati...

Drilling engineering is a high input and risk underground project, which needs the real-time down-hole diagnosis and forecast technique. Drilling string vibration signals contain full and complex vibration waves, which contains the vibration of the drilling string by itself, the vibration stimulated by the interaction of bit and the formation, the vibration induced by colliding between drill st...

purpose: in recent years high explosive bomb attacks have been increasingly directed against   civil structures by various terrorist organizations. this paper describes a numerical method for   assessing the interaction of high explosive air blast within the complex geometrical type of a   congested urban environment.   materials and methods: the first step in predicting blast effects on a targ...

Bone drilling is a major part of modern orthopaedic surgery which involves the internal fixation of fractured bones. The investigation of bone drilling described in this paper demonstrates the contribution of automation technology towards the study of bone strength. The aim of this preliminary investigation is to establish a relationship between bone drilling forces and measurements of bone min...

Oil and gas drilling operations use drilling fluids (mud) to lubricate the drill bit and stem, transport formation cuttings to the surface, and seal off porous geologic formations. Following completion of the well, waste drilling fluid is often applied to cropland. We studied potential changes in soil compaction as indicated by cone penetration resistance, pH, electrical conductivity (EC(e)), s...

today’s energy reauiraments have produced an increase in drilling activities all around the world. among this situation is the fact that all the operators are trying to minimize cost without reduction in quality. so, they are looking for new types of contracts between all drilling companies, contractors and suppliers until that with make agreement between them have successful operations. in thi...

Solids control equipment at the rig site is used to remove rock cuttings or low-gravity solids (LGS) from drilling fluids to allow the fluid to return to the active system in a re-usable condition. Typical equipment, such as shakers and centrifuges, remove LGS particles greater than 5-7 microns. Build up of finer solids in the fluid can create problems for efficient drilling such as drillpipe s...

introduction acute poisoning by oral ingestion of mixed hazardous materials can lead to multiorgan toxicity and may represent a special challenge in clinical management, in particular if little is known about the effects of the involved agents. this is especially true when industrial chemical substances have been swallowed, as a huge variety of toxic substances must be taken into account. concl...