The main task of drilling the formation by the bit is done via scraping, crushing and grinding. Discharging the fluid from the bit nozzles is done with high pressure which assists to break the rocks. Different parameters affect the bit selection and design for each drilling formation, but the most important one is drillability that depends on hardness of the formation. In this paper, the design...

This paper suggests a decentralized adaptive sliding mode formation procedure for affine nonlinear multi-quadrotor under a fixed directed topology wherever the followers are conquered by dynamical uncertainties. Compared with the previous studies which primarily concentrated on linear single-input single-output (SISO) agents or nonlinear agents with constant control gain, the proposed method is...

We investigate the dependences of galaxy star-formation history and galaxy morphology on environment, using color and Hα equivalent width as starformation history indicators, using concentration and central surface brightness as morphological indicators, and using clustocentric distance as an environment indicator. Clustocentric distance has the virtue that it can be measured with very high pre...

â  abstract: in this work, the kinetics of ethane hydrate formation has been studied experimentally and a kinetic model based on chemical affinity has been described for predicting the hydrate growth process in the stirred batch reactor at a constant volume. the experiments were done with both pure water and aqueous solution of sodium dodecyl sulfate (sds). the effect of sds on formation kineti...