The article presents measures to improve the quality of cementing production string high-performance wells. relevance proposed technological solutions is substantiated. results experimental studies installation simulating processes occurring during thickening cement slurry under action gravitational forces are presented. An algorithm for creating overpressure on wellhead fastening proposed. com...

In this study, the pulsating flow of a non-Newtonian fluid and heat transfer in pipe with uniform flux at its wall is examined analytically. The assumed to be both hydrodynamically thermally fully developed. perturbation method based on series expansion used analysis. periodic change period-averaged values friction factor Nusselt number as well velocity temperature profiles are obtained varying...

Network modeling is used to study the flow in porous media of Ellis and Herschel–Bulkley fluids, which model a large group of time-independent non-Newtonian fluids. Previous work is extended to include yield-stress and shear-thickening phenomena. We use two topologically-disordered networks representing a sand pack and Berea sandstone. Analytical expressions for the volumetric flow rate in a si...

We consider the motion of an incompressible shear-thickening power-law-like non-Newtonian fluid in $R^3$ with a variable power-law index. This system nonlinear partial differential equations arises mathematical models electrorheological fluids. The aim this paper is to investigate large-time behaviour difference $u-\tilde{u}$ where $u$ strong solution given initial data $u_0$ and $\tilde{u}$ sa...

Microfluidic droplet technology has been developing rapidly. However, precise control of dynamical behaviour of droplets remains a major hurdle for new designs. This study is to understand droplet deformation and breakup under simple shear flow in confined environment as typically found in microfluidic applications. In addition to the Newtonian–Newtonian system, we consider also both a Newtonia...

objective: etching of enamel and dentin is an important step in restoration of teeth with composite resin ensuring the retention of restoration and decreasing microleakage. this in vitro study sought to compare the effects of kimiya and etch-rite acid etchants on the microleakage of composite restorations.   methods: this experimental study was conducted on 30 sound human molar teeth. class v c...

– We study the strain response to steady imposed stress in a spatially homogeneous, scalar model for shear thickening, in which the local rate of yielding Γ(l) of mesoscopic ‘elastic elements’ is not monotonic in the local strain l. Despite this, the macroscopic, steady-state flow curve (stress vs. strain rate) is monotonic. However, for a broad class of Γ(l), the response to steady stress is n...

Abstract This paper describes the operation principles of a micro-scale rheometry equipment based on technology microchannels chip and compares it with conventional macro-scale rotational rheometer. Both techniques are used for study different solutions suspensions ceramic particles saccharides, which subjected to wide variety shear rates from their preparation processing injection in plasma sp...