We study a simple scalar constitutive equation for a shear-thickening material at zero Reynolds number, in which the shear stress sigma is driven at a constant shear rate gamma; and relaxes by two parallel decay processes: a nonlinear decay at a nonmonotonic rate R(sigma(1)) and a linear decay at rate lambda sigma(2). Here sigma(1,2)(t)= tau(-1)(1,2) integral (t)(0)sigma(t')exp[-(t-t')/tau(1,2)...

– 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—The detection of the polymer melt state during manufacture process is regarded as an efficient way to control the molded part quality in advance. Online monitoring rheological property of polymer melt during processing procedure provides an approach to understand the melt state immediately. Rheological property reflects the polymer melt state at different processing parameters and is v...

An existing rheological model of skeletal muscle (Forcinito et al., 1998) was modified with a nonlinear Maxwell fluid element to provide a phenomenological model capable of analyzing the strain-stiffening behavior typically found in passive, and occasionally observed in active, skeletal muscle. This new model describes both active and passive muscular behavior as a combination of the behavior o...

The complex flow behavior of polymer-based soft colloidal model systems was investigated using steady and oscillatory shear to prove new concepts for advanced rheological characterization. In the very dilute regime we investigated high molecular weight polybutadiene star polymers to quantify the internal relaxation time arising from the polymeric nature of these ultra-soft colloids. The observe...

in the present study, the nonlinear model of non-newtonian blood flow in cosine-shape stenosed elastic artery is numerically examined. the model is carried out for axisymmetric, two-dimensional and fully developed blood flow. the vessel wall is assumed to be have time-dependent radius that is important factor for study of blood flow. the cosine-shape stenosis convert to rigid artery by using a ...

The aim of this work was to quantify the effects of psyllium fiber addition to wheat flour at the levels of 0, 1, 2, 3 and 4% on the rheological behavior of the dough. The rheological properties of the dough were investigated using the rheological device, Farinograph. Upon the addition of psyllium fiber, a significant increase in Farinograph water absorption, simultaneously with the increase of...

The aim of this study was to characterize and optimize the different hydrogel formulations of the methanolic root extract of Buchanania lanzan (MEBL) with an objective towards the development of a suitable topical delivery system. The gel formulations were prepared with different concentrations of polymer (Carbopol-940) and 0.5% of the active fraction (ethyl acetate sub-fraction of MEBL). Diffe...

We investigated experimentally the rheological behavior of whole human blood subjected to large amplitude oscillatory shear under strain control to assess its nonlinear viscoelastic response. In these rheological tests, the shear stress response presented higher harmonic contributions, revealing the nonlinear behavior of human blood that is associated with changes in its internal microstructure...