scattering of an incoming wave train by a discontinuity at the upper surface of the ocean over a uniform porous bottom of finite depth is considered here in the framework of linearized water wave theory. by employing residue calculus method, the reflection and transmission coefficient are obtained. these coefficients are computed numerically for different values of the porosity parameter g and ...

the neat bitumen, an oil refining by-product, has its own inherent weakness under long-time loading at low and high temperatures. these performance limitations of neat bitumen have led researchers to modify its physical andmechanical properties. according to several studies, polymers can be used to modify the properties of bitumen. due to much lower production costs and aiming to reduce environ...

the continuous improvement of eaf performance is crucial for the increase in productivity and cost effectiveness and to render an environmental friendly process. rhi supports these targets by providing a diverse range of refractory and process solutions. chemical energy in practical operation by injection of gaseous media like oxygen and natural gas, and solid materials like carbon have become ...

the narrow operating window between pore pressure and fracture pressure makes drilling difficult in some operations. a feasibility study of managed pressure drilling (mpd) is carried out on iran darquain oil field. the previous wells drilled in this field showed that mud returns were lost during drilling gadvan formation. the present work addresses this problem by means of surface back pressure...

Several investigations have been devoted towards understanding the coating process in fluidized beds. Most of these studies focused on spraying liquid droplets over the bed. However, due to the complexity of these systems, more investigations are still required to quantify the effect of operating conditions on the coating criteria. The present work aims at fundamentally understanding and pr...

Abstract The paper introduces a new type of rules into Natural Deduction, elimination by composition. Elimination composition replace usual in the style disjunction and give more direct treatment additive disjunction, multiplicative conjunction, existence quantifier possibility modality. have an enormous impact on proof-structures deductions: they do not produce segments, deduction trees remain...