The purpose of this study was to compare the performance of chemomechanical caries removal (CMCR) with that of conventional drilling for efficacy of caries removal, time spent, morphological changes and microhardness of surface dentin, and microleakage of subsequent restorations. Forty-six carious deciduous molars were randomly divided into two groups: one each for caries removal by (1) CMCR an...

Piedmont tectonic belts are rich of oil and gas resources, however the intense tectonic stress and broken formation may cause great drilling problems in piedmont structures such as borehole collapse, lost circulation and gas cutting. Through analysis of in situ stress properties, bedding structure and mechanical characteristics, wellbore instability mechanism was expounded from rock mechanics, ...

Public health concerns related to the expansion of unconventional oil and gas drilling have sparked intense debate. In 2012, we published case reports of animals and humans affected by nearby drilling operations. Because of the potential for long-term effects of even low doses of environmental toxicants and the cumulative impact of exposures of multiple chemicals by multiple routes of exposure,...

One of the most significant problems encountered in machining, particularly in drilling, is that of burr formation. Burrs usually comprise of work piece material which has been plastically deformed during the machining process and projects beyond the desired edge of the work piece. The adverse effects of burrs depend on the component application but may include; stress concentration and related...

The accurate control of the wellbore pressure not only prevents lost circulation/blowout and fracturing formation by managing the density of the drilling fluid, but also improves productivity by mitigating reservoir damage. Calculating the geothermal pressure of a geothermal well by constant parameters would easily bring big errors, as the changes of physical, rheological and thermal properties...

The problem of slow drilling in deep shale formations occurs worldwide causing significant expenses to the oil industry. Bit balling which is widely considered as the main cause of poor bit performance in shales, especially deep shales, is being drilled with water-based mud. Therefore, efforts have been made to develop a model to diagnose drilling effectivity. Hence, we arrived at graphical cor...

Nowadays, one would think that after years of massive concrete and steel construction in Spain, there are not many wood structure buildings left to be refurbished except for some palaces or cathedrals. However, if we go for a walk and have a look at the old part of any city, we will realize that still most of the buildings have a wood structure. In spite of the fact that the majority of urban r...

Factors underlying biological and socio-biological states include a complex interplay of several biological, behavioral, economic, and social factors. A reductionist view usually assesses the interplay of factors using a “drill-down” approach by examining smaller parts of a system under the paradigm that these parts, when fit-together, will translate to a fully functional whole. However, often ...