In this study, a critical analysis was carried out on the various classes of drilling machine to establish their performance based applications and also, have comparative evaluation between electrically driven machines (EDDM) manually operated (MODM). ancient days, flat punch used make holes materials, but due advancements in technology, are now being instead, making work easier faster. There d...

We reviewed 13 cases of osteochondritis dissecans of the patella followed-up for 18 months to 19 years. Two were treated conservatively with excellent results, and 11 by operation with six excellent, four good and one fair result. There was complete radiographic healing of the defect in 10 cases and partial healing in three. The size of the osteochondritic lesion appeared to be of prognostic si...

Purpose. Development of a methodology for optimizing the technological parameters airlift operation, based on analysis pressure balance in annulus and drill string that occurs during drilling. Methodology. The tasks were solved by complex research method, which includes review generalization literary patent sources, analytical studies existing methods drilling with reverse circulation using an ...

K e y w o r d s F o u r t h g r a d e fluid, Unsteady flow, Lie symmetries. 1. I N T R O D U C T I O N In recent years, considerable efforts have been usefully devoted to the s tudy of flow of nonNewton ian fluids. This is ma in ly due to their m a n y appl icat ions in pe t ro leum drilling, manufactu r ing of food and paper, and other similar activities. A vast a m o u n t of l i te ra ture i...

This paper examines the diverse nature of user reactions to information technology (IT) within the social-historical context of its organizational use. Employing activity theory as a conceptual framework, we conduct an interpretive analysis of physicians work, perceptions, and IT usage experience at a large community hospital to understand why some of these physicians were favorably disposed to...

Control of well drilling operations poses a challenging issue to be tackled. The loss of well control could lead to the occurrence of blowout as a severe threat, involving the risk of human lives and environmental and economic consequences. Conventional proportional-integral (PI) controller is a common practice in the well control operation. The small existing margin between pore pressure and f...

The distinguishing characteristics of carbon fibre reinforced laminates, like low weight, high strength or stiffness, had resulted in an increase of their use during the last decades. Although parts are normally produced to “near-net” shape, machining operations like drilling are still needed. In result of composites non-homogeneity, this operation can lead to delamination, considered the most ...

SUMMARY The use of composite laminates in complex structures has increased significantly. However, there are still some issues when considering their use, mainly related with machining, leading to some difficulties and lack of acceptance. In this work, a methodology to evaluate drill geometry and feed rate based on thrust force and delamination extension is presented. INTRODUCTION For the past ...