OBJECTIVES To investigate whether a surgeon can drill accurately a specified angle and whether surgeon experience, task repetition, drill bit size and perceived difficulty influence drilling angle accuracy. METHODS The sample population consisted of final-year students (n=25), non-specialist veterinarians (n=22) and board-certified orthopaedic surgeons (n=8). Each participant drilled a hole t...

Managed pressure drilling is a sophisticated pressure control method which is intended to meet increasingly high demands in drilling operations in the oil and gas industry. With this method, the well is pressurized and the drilling mud is released through a control choke which can be used to actively control/reject pressure variations. Such a control system needs to handle several disturbances,...

Drilling consists of 2 processes: breaking the formation with a bit and removing the drilled cuttings. In rotary drilling, rotational speed and weight on bit are used to control drilling, and the optimization of these parameters can markedly improve drilling performance. Although fluids are used for cuttings removal in terrestrial drilling, most planetary drilling systems conduct dry drilling w...

Glass Fiber Reinforced Plastic composites have an increased application in recent days, due to its enhanced structural, mechanical and thermal properties. The heterogeneous nature of this kind of materials makes complications during machining operations. Drilling of holes in GFRP becomes almost unavoidable in fabrication. However, drilling is a common machining practice for assembly of componen...

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 ...

[1] Single-hole hydrogeologic experiments were conducted with a drillstring packer in Integrated Ocean Drilling Program Hole 1301B, which penetrates 318 m into 3.5-Ma upper oceanic basement on the eastern flank of the Juan de Fuca Ridge. Seven constant-rate injection tests were conducted in open hole, with the packer inflated at three depths in the deepest 166 m of the basement section. The pri...

We report quantitative analyses of drilling predation on the free-living, tube-dwelling serpulid polychaete Ditrupa arietina from the Cope Cabo marine succession (Pliocene, Spain). Tubes of D. arietina are abundant in the sampled units: 9 bulk samples from 5 horizons yielded ~5925 specimens of D. arietina. Except for fragmentation, tubes were well preserved. Complete specimens ranged from 3.1 t...

The presence of abundant age-diagnostic dinoflagellate cysts in Ocean Drilling Program (ODP) Hole 913B (Leg 151), Deep Sea Drilling Project Hole 338 (Leg 38) and ODP Hole 643A (Leg 104) has enabled the development of a new biostratigraphy for the Eocene^Oligocene interval in the Norwegian^Greenland Sea. This development is important because the calcareous microfossils usually used for biostrati...

The hole drilling method is based on the measuring of the surface relaxed strains when a small hole is drilled on the examined component. From the relaxed strains, measured generally by using special strain gage rosette, the residual stresses is computed by using proper influence coefficients, provided also by the ASTM E837-08 standard. Such influence coefficients are obtained by numerical simu...

Drilling tools currently used in surgery depends only on the surgeon’s manual skills to stop the penetration when completing a hole. This paper presents a modular mechatronic system for automatic bone drilling in surgery. The development of a “modular system” that is compatible with motor-driven drills that are commercially available, rather than developing a new surgical drill, is emphasized. ...