Surface treatment of silica fume with sulfuric acid prior to incorporation in a cement matrix resulted in composites exhibiting increases in tensile strength by 12%, tensile modulus by 72%, tensile ductility by 57%, abrasion resistance by 20%, loss tangent by 30–80%, flexural storage modulus by 80–120%, and flexural loss modulus by 160–300%, relative to the values obtained by using as-received ...

The purpose of this study was to evaluate the dynamic viscoelastic properties of experimental silicone soft lining materials, Silastic MDX 4-4210 reinforced with silica fillers. Storage modulus (E'), loss modulus (E") and damping factor (tan delta) were determined using a dynamic mechanical analyzer under a deformation strain level of 0.27% at test frequency and a temperature range of 1 Hz and ...

In this study, the interaction between the silica filler and polydimethylsiloxanes (PDMS) was investigated from the aspects of the bound rubber and morphological characterization. With special attention to the dynamic properties, the dynamic test was conducted by dynamic shear rheometer. The results show that the modified fillers disperse uniformly within PDMS matrix without aggregation and con...

The objective of this study was to determine rheological behaviors of maple veneer plastic composite (MVPC) prepared by full cell preparation technology through the use of a rotational rheometer. The results showed that at 25 to 105 °C, the storage modulus G' and loss modulus G'' of the MVPC were apparently higher than that of the control. In the range 105 to 210 °C, the storage modulus G' of t...

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...

in this research, high oxygen-barrier films were organized based on low-density polyethylene (ldpe)/ ethylene vinyl alcohol (evoh)/ polyethylene-grafted maleic anhydride (ldpe-g-ma) compatibilizer. the effects of 10–30 wt. % evoh and 0–10 wt. % ldpe-g-ma loadings on the properties of final films were evaluated. the morphology of specimens was observed by using scanning electron microscopy (sem)...

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...

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...

This study experimentally investigates the effect of multi-walled carbon nanotubes (MWNT’s), as a reinforcing material, on the physical properties of heavy-weight oil well cements. A candidate well is selected and the properties of the cement slurry used in a problematic section of the well are tested in the laboratory. Carbon nanotubes (CNT’s) are added as fibers to the cement slurry and the i...