shear modulus and damping ratio are important input parameters in dynamic analysis. a series of resonant column tests was carried out on pure clays and sand-clay mixtures prepared at different densities to investigate the effects of aggregate content, confining stress, void ratio and clay plasticity on the maximum shear modulus and minimum damping ratio. test results revealed an increase in the...

blown bitumen (110/10) was mixed with heavy vacuum slops (h.v.s), 60/70 penetration grade bitumen and recycled isotactic polypropylene (ipp) at different levels. the resulting resins were used to impregnate non-woven poly(ethylene terephthalate) fibers to form composites. the modulus and penetration grade of the resulting bituminous resins were determined. it was found that these bituminous res...

A new three-dimensional unit cell model has been developed for modeling three constituent phases including inclusion, interphase and matrix. The total elastic modulus of nano-composite is evaluated.  Numerical results are in good agreement with the previous proposed theoretical modeling. Higher matrix and inclusion elastic modulus both can dramatically influence the total elastic modulus.

The response of activated skeletal muscle to a ramp stretch is complex. Force rises rapidly above the isometric plateau during the initial phase of stretch. However, after a strain of approximately 1-2%, force yields and continues to rise but with a slower slope. The resistance to stretch during the initial phase can be characterized by the stiffness of the muscle and/or the preyield modulus (E...

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 ...

Normal 0 false false false EN-US X-NONE AR-SA The ratio of compression yield strength to the initial tensile yield strength is called Bauschinger effect factor, BEF. A nonlinear strain hardening mathematical model is proposed for 7075 aluminium alloy (A7075). Uniaxial tension-compression experimental data are used to figure out a suitable model to study the BEF. Hence, uniaxial tension-co...

the effect of impact modifier on creep behavior of wood flour- recycled polypropylene composites has been evaluated in this work. for this purpose, impact modifier (ethylene vinyl acetate) and recycled polypropylene were mixed with wood flour (50/50% w/w) as well as the impact modifier (0, 3%, 6% and 9%) by a counter-rotating twin-screw extruder to manufacture the wood flour- recycled polypropy...

BACKGROUND No unified method exists to effectively predict and monitor progression of pulmonary arterial hypertension (PAH). We assessed the longitudinal relationship between a novel marker of cardiopulmonary reserve and established prognostic surrogate markers in patients with pulmonary vascular disease. METHODS AND RESULTS Twenty participants with confirmed (n = 14) or at high risk (n = 6) ...

In this research, the influence of adding micro- and nano- sized calcium carbonate powders to nylon-66 was investigated. Mechanical properties of micro and nano- composites, including tensile strength, elongation, and Young’s modulus, before and after ageing, were determined and analyzed. For this purpose, micro- and nano-sized CaCO3 particles were used as fillers to prepare micro-composites (c...