the preparation and characterization of the vinyltriethoxysilane-modified silica nanoparticles were investigated. also the surface tension of polystyrene, native (hydrophilic) silica and silane-modified (hydrophobic) silica were determined. two kinds of polystyrene/silica (treated and non-treated) nanocomposites were prepared with different filler loadings by solution method. their viscoelastic...

We show that the electric field driven surface instability of viscoelastic films has two distinct regimes: (1) The viscoelastic films behaving like a liquid display long wavelengths governed by applied voltage and surface tension, independent of its elastic storage and viscous loss moduli, and (2) the films behaving like a solid require a threshold voltage for the instability whose wavelength a...

OBJECTIVE To assess in a high-resolution model of thin liver rat slices which viscoelastic parameter at three-dimensional multifrequency MR elastography has the best diagnostic performance for quantifying liver fibrosis. MATERIALS AND METHODS The study was approved by the ethics committee for animal care of our institution. Eight normal rats and 42 rats with carbon tetrachloride induced liver...

In this work, the material properties of a series of fly ash/polyurea composites were studied. Dynamic mechanical analysis was conducted to study the effect of the fly ash volume fraction on the composite’s mechanical properties, i.e., on the material’s frequencyand temperature-dependent storage and loss moduli. It was found that the storage and loss moduli of the composite both increase as the...

An ultrasonic technique was used to study the changes of the rheological properties of dough during fermentation at 37C and compared with the ertensional properties of fermented dough obtained from tensile tests carried out in a Universal Testing Machine. The velocity and attenuation of a longitudinal wave (P-wave) propagated through the dough samples were measured and analyzed to obtain the vi...

BACKGROUND The viscoelastic properties of cells have been investigated by a variety of techniques. However, the experimental data reported in literature for viscoelastic moduli differ by up to three orders of magnitude. This has been attributed to differences in techniques and models for cell response as well as to the natural variability of cells. RESULTS In this work we develop and apply a ...