film coating solutions containing different grades of hpmc (e5, e15 and e50) with and without polyethylene glycol (with various molecular weights) were examined by an oscillatory method, using haake cv 100 rheometer. fundamental rheological parameters (?, g? and g² ) were measured over the frequency range from 0.04 to 2 hz. the variation with frequency of the loss tangent (a ratio of viscous to...

In this article, bending, buckling, and free vibration of viscoelastic sandwich plate with carbon nanotubes reinforced composite facesheets and an isotropic homogeneous core on viscoelastic foundation are presented using a new first order shear deformation theory. According to this theory, the number of unknown’s parameters and governing equations are reduced and also the using of shear correct...

the rheological properties of four different kuwaiti crude oils in the presence of polyacrylamide (paa) were investigated. paa was varied at three different concentrations of 25, 50, and 75 ppm to study the viscoelastic properties in the untreated samples. four different temperatures (25, 30, 35, and 40 °c) were used to evaluate different viscoelastic parameters of the treated and untreated kuw...

This paper describes our experimental testing of linear viscoelastic creep behaviours in HamiMelon. Experimental data shows that HamiMelon has complex viscoelastic property which cannot be well described by the standard model. Consequently, this study develops a fractional derivative model to describe such complex viscoelastic creep behaviours of Hami Melon. The analytical creep function of the...

little is known about the interaction of tissue conditioners and modeling plastics. this study evaluates the influence of a variety of commercial tissue conditioners on alteration of viscoelastic properties of modeling plastics.in this in vitro study, the dynamic viscoelastic properties of four commercially available tissue conditioners (tc), visco-gel (vg), gc soft-liner (sl), fitt (ft), and c...

This paper describes the dynamics identification of the foot viscoelasticity of humanoid robots. It is important to know correctly dynamics parameters of link and joint which constitute a robot for its simulation and model based control. When walking, humanoids receive impulsive force at each step. Some humanoids have shock absorber and rubber bush in their soles. In simulation, accuracy of ine...

The rheological properties of four different Kuwaiti crude oils in the presence of polyacrylamide (PAA) were investigated. PAA was varied at three different concentrations of 25, 50, and 75 ppm to study the viscoelastic properties in the untreated samples. Four different temperatures (25, 30, 35, and 40 °C) were used to evaluate different viscoelastic parameters of the treated and untreated Kuw...

needle insertion is a minimally invasive technique in diagnosing and treating tumors. however, to perform a surgery accurately, the tissue should have minimum amount of displacement during needle insertion so that it reaches the target tissue. therefore, the tissue membrane has to move less to decrease rupturing under the membrane. in this study, the effect of different design parameters on dis...

Soft tissue characterization and modeling based on living tissues has been investigated in order to provide a more realistic behavior in a virtual reality based surgical simulation. In this paper, we characterize the nonlinear viscoelastic properties of intra-abdominal organs using the data from in vivo animal experiments and inverse FE parameter estimation algorithm. In the assumptions of quas...

In this work, and based on numerical optimization techniques, constitutive parameters for viscoelastic materials are determined using a inverse problem formulation. The optimization methodology is based on experimental results obtained in the frequency domain, for a CFRP-Carbon Fibre Reinforced Polymer, through DMA-Dynamic Mechanical Analysis. The relaxation modulus of viscoelastic materials is...