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.

the brass tubes with foam cores of alsi7sic3, alsi7sic3fe1 and alsi7sic3fe3 were produced as the crush-boxes with circle and square cross-section. then axial compressive behavior and energy absorption capability of the foam-filled tubes were investigated during the quasi-static progressive plastic buckling. the uniaxial compressive stress–strain curves of the foam-filled brass tubes exhibited t...

in many processes polymeric foams can be produced by using chemical or physical blowing agents. in this work for polyethylene foam production, the chemical blowing agents and compression moulding process were employed. at first, by using dsc diagram of two polyethylene grades, a suitable polyethylene grade was selected for foam production and then we discuss about blowing agent critical percent...

The present work was aimed to examine the effects of incorporation of each of two different types of nanoclay, i.e. Cloisite Na+ and Cloisite 30B, into PVA foam on cellular morphology and water absorption capacity. Foam samples containing 0.0-10.0 wt% of each of the two types of nanoclay alone were prepared using mechanical foaming. Accordingly, PVA/organoclay/water suspensions were prepare...

The goal of this study was improvement of sandy soil using a combination of polystyrene foam container waste and Portland cement. For this purpose, Babolsar sand was used as the base soil. Strips of disposable polystyrene foam container waste in “chips” of 50 ´ 5 mm and 50 ´ 10 mm were added to the soil at 0.0%, 0.1%, 0.2% and 0.3% by weight along with 3% Portland cement at a relative density o...

abstract: this paper presents the results of studies concerned with the preparation of fresh food foams based on egg white and various hydrocolloids including iranian gum tragacanth, guar and xanthan gums at different concentrations (0.002-0.040% w/w). the basic physical parameters of the obtained foams such as overrun, stability and morphology of gas bubbles were measured. viscosity measuremen...

For the past three decades the quantity of petroleum (both oil and oil plus gas) found per foot of drilling effort in the United States for any given year can be expressed as a secular decrease of about 2 percent per year combined with an inverse function of drilling effort for that year. Extrapolation of energy costs and gains from petroleum drilling and extraction indicates that drilling for ...

Abstract— Due to the superior physical and mechanical properties Glass fiber-reinforced (GFRP) composite materials are very attractive for applications like aerospace and air craft structural components. This results a large number of research papers on machining of these composite laminates. Out of all the machining operations, most commonly used operation is drilling. However, drilling operat...

Because neurosurgery and orthopedic surgery often require the drilling of bones, this paper attempts to solve the problem of bone drilling. The goal is to realize a control system, which is able to drill with a contact drilling force and can automatically stop drilling at the moment of breaking through. In particular, both the de drilling mntor control and the feed rate control are driven by fo...