The aim of this study was to evaluate histomorphometrically the influence of two techniques of dental implant site preparation on bone healing around titanium implants. Fifteen male Wistar rats (±300 g) were used in the study. Each tibia was randomly assigned to receive the implant site preparation either with a conventional drilling technique (control - DRILL group) or with a piezoelectric dev...

On the UK Continental Shelf, up to 80,000 tonnes wet weight of oily drill cuttings are produced annually. These are heterogeneous wastes generated from the petroleum drilling industry, composed of significant percentages of hydrocarbons, heavy metals and chlorides. Since 1992, the discharge of drill cuttings containing more than 1% oil-on-cuttings has been prohibited. Moreover, the extensive in...

The search for existing or past life in the Universe is one of the most important objectives of NASA’s mission. In support of this objective, an ultrasonic based mechanism is being developed to allow probing and sampling of rocks and soil. The novel lightweight Ultrasonic/Sonic Driller/Corer (USDC) used in this study takes advantage of its ability to drill with low axial force and low power. Th...

To investigate the origin of fractures at the distal locking site of the Gamma nail, we loaded ten paired human cadaver femora fixed with a Gamma nail in torsion until they fractured. When an awl was hammered in to start the hole for distal locking a fissure appeared in the lateral cortex of all the femora, and the mean torsional load to create a fracture was reduced by 57.8% compared with that...

We studied the various drill bits available for engineering purposes, and compared them with standard orthopaedic drill bits, using continuous temperature recording at 0.5 mm, 1.0 mm and 1.5 mm from the edge of a 2.5 mm hole as it was drilled in fresh cadaver human tibia. We found that some commercially available drill bits performed better than their orthopaedic equivalents, producing signific...

A reliable method of transmitting downhole information to the surface while drilling is essential to improve drilling applications. We have designed a numerical algorithm for simulation of electric-signal transmission through the drill string, based on the telegrapher equation (a circuit model). The drill string is then represented by a transmission line with varying geometrical and electromagn...

Fibre reinforced plastics are increasing their importance as one of the most interesting groups of material on account of their low weight, high strength and stiffness. To obtain good quality holes, it is important to identify the type of material, ply stacking sequence and fibre orientation. In this paper, the drilling of quasi-isotropic hybrid carbon+glass/epoxy plates is analyzed. Two commer...

Compositional distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in Nigerian oil-based drill-cuttings have been studied for evidence of petrogenic and/or pyrogenic effects with recommendations for the strict enforcement of the ban on the use of oil-based mud in drilling by government regulatory agencies and prior bio-treatment of the drill cuttings before final fate. Laboratory...

The drill & blast method is still the most typical method for medium to hard rock conditions. It can be applied to a wide range of rock conditions. Some of its features include versatile equipment, fast start-up and relatively low capital cost tied to the equipment. On the other hand, the cyclic nature of the drill & blast method requires good work site organization. Blast vibrations and noise ...

Hole drilling operations are common in fibre reinforced plastics FRP’s to facilitate fastener assembly to other parts in more complex structures. As these materials are non-homogeneous, drilling causes some damages, like delamination, for example. Delamination can be reduced by a careful selection of drilling parameters, drill material and drill bit geometry. In this work two types of laminates...