A metal-based matrix is usually used for the fabrication of diamond bits in order to achieve favorable properties and easy processing. In the effort to reduce the cost and to attain the desired bit properties, researchers have brought more attention to diamond composites. In this paper, Fe-based impregnated diamond composites for drill bits were fabricated by using a pressureless infiltration s...

INTRODUCTION Specogna (Babe) gold property consisting of 41 full claims and seven fractions is 17.6 kilometres south of the town of Port Clements on Graham Island (Fig. 48). The showing is a prospecting dijcovery, found in late 1970 by Efrem Specogna and Johnny Trico. Five companies optioned the property iuccessively from 1971 to 1975 during which time geochemical sampling, trenching, and diamo...

Superadiabatic Partial Oxidation for Hydrogen and Sulfur Production from Hydrogen Sulfide The Gas Technology Institute has been investigating superadiabatic partial oxidation concepts to not only develop novel, cost-effective processes to recover hydrogen and sulfur from hydrogen sulfide, but also produce hydrogen from natural gas and other liquid hydrocarbons, and gasify solid feedstocks, incl...

microleakage can be responsible for tooth hypersensitivity, secondary caries, and the possibility of pathological pulp alterations in restored teeth. recently, alternative methods for tooth preparation such as laser irradiation have been studied; but there are limited studies on primary teeth. the aim of this in vitro study was to compare the degree of microleakage of composite restorations pre...

Beside the twist drill, the effects of various drill geometries were rarely discussed in analytical fashion. This study presents a comprehensive analysis of delamination in use of various drill types, such as saw drill, candle stick drill, core drill and step drill. In this analysis, the critical thrust force at the onset of delamination is predicted and compared with the twist drill. © 2003 El...

In this paper, we describe a new technique for the automatic orientation of bedding in drill core from digital images. Images are planar pictures of the drill core, and we show that it is possible to determine layer orientation without rotating the core on the full circumference. More precisely, we show that angle information can be extracted by applying image processing and a mathematical desc...

This paper presents a study of hole quality and energy consumption in the process of drilling a thermoplastic polymeric material, polyether-ether-ketone, reinforced with 30% glass fibers (PEEK-GF30). PEEK-GF30's capacity to be machined has focused on turning operations. Studies of drilling involving thermoplastic polymeric materials have considered materials with other types of matrices, or rei...

An SiCf/SiC composite has the following excellent properties: high strength, low specific gravity, and temperature resistance, which great prospects in combustion chamber of rockets or aero engines. Hole-making parts is an important processing method. Generally, water-based oil-based coolants are avoided, so dry drilling primary hole-making approach for SiCf/SiC. However, abrasion resistance ha...