OBJECTIVE The purpose of the study was to measure the viscoelastic properties of four dental resin composite cements using a dynamic mechanical analysis technique. METHODS Dynamic torsional loading was conducted in the frequency range from 1 to 80 Hz. Cement specimens were tested after storage in 37 degrees C water for 24 h. One group was thermal cycled prior to testing. Measurements were tak...

the biopolymer-based nanocomplexes are a group of nanocapsules that are used for encapsulation and control delivery of nutraceuticals. they are formed by binding of proteins and polysaccharides. in this study, complex formation between pectin and sodium caseinate was taken place by addition of pectin solutions(0.2, 0.45 and 0.7 % w/v) into the caseinate solutions (0.5, 1 and 1.5 % w/v) and adju...

BACKGROUND The purpose of this study was to compare the frequency-dependent viscoelastic properties of human and bovine cartilage. METHODS Full-depth cartilage specimens were extracted from bovine and human femoral heads. Using dynamic mechanical analysis, the viscoelastic properties of eight bovine and six human specimens were measured over the frequency range 1 Hz to 88 Hz. Significant diff...

In this study the rheology of blood clot is measured with the help of rotational rheometer. Several shear strain (0.5, 1 and 2%) are applied with two frequencies (5 and 10 Hz) from the incipient time of clot formation and the response of the sample is measured with the form of shear stress and the phase lag which is interpreted with storage and loss moduli. In this study the ratio of loss to st...

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 ...

Dynamic modulus characterizes the viscoelastic behavior of asphalt materials and is the most important input parameter for design and rehabilitation of flexible pavements using Mechanistic–Empirical Pavement Design Guide (MEPDG). Laboratory determination of dynamic modulus is very expensive and time consuming. To overcome this challenge, several predictive models were developed to determine dyn...

handling of endodontic sealers is greatly dependent on their elasticity and flow ability. we compared the viscoelastic properties of three root canal sealers.ah plus (dentsply, de trey, konstanz, germany), endofill (dentsply hero, petrópolis, rio de janeiro, brazil) and ah26 (dentsply, de trey, konstanz, germany) were mixed according to the manufacturers' instructions. the resulted pastes were ...

This study aimed to characterise viscoelastic properties of different categories of chordae tendineae over a range of frequencies. Dynamic Mechanical Analysis (DMA) was performed using a materials testing machine. Chordae (n=51) were dissected from seven porcine hearts and categorised as basal, marginal, strut or commissural. Chordae were loaded under a sinusoidally varying tensile load at a ra...