NIOSH continues to conduct respirable dust control research for surface mine blasthole drilling operations. Research areas have included testing variables (shroud leakage area, drill deck cross-sectional area, shroud height, collector-to-bailing airflow ratio, etc.) that have the most impact on respirable dust control, development of a dust collector inlet hood, development of a dust collector ...

Oil-based drilling fluid is used more and more in the field of oil and gas exploration. However, because of unrecyclable treating agent and hard treatment conditions, the traditional treating technologies of waste oil-based drilling fluid have some defects, such as waste of resource, bulky equipment, complex treatment processes, and low oil recovery rate. In this work, switchable deoiling agent...

Background: Currently clomiphene citrate is the first-line treatment to induce ovulation in women with polycystic ovarian syndrome (PCOS). Surgical therapy with laparoscopic ovarian drilling (LOD) may avoid or reduce the need for gonadotropins. Objective: To determine the effectiveness and safety of LOD compared with ovulation induction in subfertile women with clomiphene-resistant PCOS. Search...

Accurate assessment of the subsurface mechanical characteristics and how they correlate with dielectric properties is crucial to optimize future drilling and sampling investigations on planetary bodies. For 12 different types of basaltic rocks with different hardnesses, we use capacitive cells to measure the real part of the dielectric constant over the frequency range 100–1000 MHz, and a Schmi...

The aim of this paper is to utilise genetic algorithm approach to investigate the effect of CNC drilling process variables such as spindle speed, drill diameter, material thickness, and feed rate on thrust force and torque generated during the drilling of mild steel plate using H.S.S drill. To find out the relationship between drilling process variable on thrust force and torque generated to th...

The process of borehole drilling is a nonlinear and many dimensional process. During drilling it is possible occurrence of some complications (for example transition of drilling tool in layer with anomalous pressure). New method of identification of rock layers with anomalous pressure was proposed and tested on real plant data.

in the present study, five modeling approaches of ra, mlp, mnn, gff, and canfis were applied so as to estimate the radial overcut values in electrochemical drilling process. for these models, four input variables, namely electrolyte concentration, voltage, initial machining gap, and tool feed rate, were selected. the developed models were evaluated in terms of their prediction capability with m...

Renewable energy is seen as the future source for meeting the world’s growing demand, with geothermal offering a constant and independent supply. Tapping geothermal energy is not always straightforward as deep drilling is required in order to access this high -temperature resource. Geothermal drilling is expensive and is financed by the operator (usually districts or state representatives) with...

This work is devoted to the investigation of oscillations in a drilling system using an induction motor with wound rotor as a drive. It is motivated by the problems of drilling rig failures in the oil and gas industry. The study is based on a modified version of the mathematical model of a drilling rig proposed by scientists from the Eindhoven University of Technology. The model of drilling rig...