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In this paper, a dynamic viscoelastic problem is numerically studied. The variational problem is written in terms of the velocity field and it leads to a parabolic linear variational equation. A fully discrete scheme is introduced by using the finite element method to approximate the spatial variable and an Euler scheme to discretize time derivatives. An a priori error estimates result is recal...

We investigated the mechanical properties of two abundant, cytoplasmic proteins from Acanthamoeba, profilin and actin, and found that while both profilin and nonfilamentous actin alone behaved as solids, mixtures of the two proteins were viscoelastic liquids. When allowed to equilibrate, profilin formed a viscoelastic solid with mechanical properties similar to filamentous and nonfilamentous ac...

Relaxation indentation experiments using atomic force microscopy (AFM) are used to obtain viscoelastic material properties of soft samples. The quasilinear viscoelastic (QLV) model formulated by Fung (1972, "Stress Strain History Relations of Soft Tissues in Simple Elongation," in Biomechanics, Its Foundation and Objectives, Prentice-Hall, Englewood Cliffs, NJ, pp. 181-207) for uniaxial compres...

Finite Element Analysis (FEA) was used to model viscoelastic effects in the compression of polyurethane (PU) foam. Modelling of the impact compression of foam cubes predicted that a compressed region propagated through the sample, causing step increases in the stress traces. Modelling of head impacts on gymnastic ‘crash’ mats, made of PU chip foam, revealed that the majority, but not all, of th...

Among viscoelastic substances, sodium hyaluronate has become the most popular for intraocular surgeries since the introduction of Healon((R)) (sodium hyaluronate 1%, 4 x 10(6) daltons) in 1979. This review focuses on the recent development of a new generation of sodium hyaluronate agents with new rheologic properties and the relevant new techniques used in cataract, glaucoma, corneal, and vitre...

Studies were conducted to evaluate the combined effects of spontaneous fermentation and amylase-rich flours (ARF) on some nutritive value, functional and viscoelastic properties of cowpea-fortified nixtamalized maize. A 2 x 3 x 3 factorial design, with fermentation medium, fermentation time and ARF level, was performed. The blends were fermented for the specific times and analysed for their tit...

SURGICAL TECHNIQUE The bubble mirror technique consists of the stabilization of the anterior chamber by means of a plug made with a combination of conveniently placed air and viscoelastic material. A line arises at interface between the air and viscoelastic where the anterior chamber angle reflected can be seen as in a mirror (bubble mirror). DISCUSSION The viscoelastic-air plug offers three ...

We present the dynamic velocity profiles of a Newtonian fluid (glycerol) and a viscoelastic Maxwell fluid (CPyCl-NaSal in water) driven by an oscillating pressure gradient in a vertical cylindrical pipe. The frequency range explored has been chosen to include the first three resonance peaks of the dynamic permeability of the viscoelastic-fluid--pipe system. Three different optical measurement t...

A mathematical model describing the constitutive properties of biofilms is required for predicting biofilm deformation, failure, and detachment in response to mechanical forces. Laboratory observations indicate that biofilms are viscoelastic materials. Likewise, current knowledge of biofilm internal structure suggests modeling biofilms as associated polymer viscoelastic systems. Supporting expe...