this research concentrates on the effects of low frequency, vertical mechanical vibration during solidification on the microstructure and mechanical properties of a380 aluminum alloy. two series of sr-modified and al-5ti-b grain refined a380 alloy samples were solidified in both static and dynamic conditions in the frequency and amplitude of 60 hz and 0.2 m, respectively. their physical, micro-...

4-chloromethyl styrene (cms) was copolymerized with different monomers such as methyl methacrylate (mma), methyl acrylate (ma), 2-ethylhexyl acrylate (eha) by free radical polymerization method at 70 ±1°c using a,a'-azobis(isobutyronitrile) (aibn) as an initiator. the copolymer compositions were obtained using related 1hnmr spectra and the polydispersity of the copolymers were determined using ...

Mechanical unfolding and refolding may regulate the molecular elasticity of modular proteins with mechanical functions. The development of the atomic force microscopy (AFM) has recently enabled the dynamic measurement of these processes at the single-molecule level. Protein engineering techniques allow the construction of homomeric polyproteins for the precise analysis of the mechanical unfoldi...

the transport properties of liquids and gases through polymeric materialsplay a very important role in some areas of industrial applications. in thisstudy, natural rubber (nr)/caco3 composites were prepared by melt mixingmethod. by equilibrium swelling test, the transport process of toluene in the prepared natural rubber composites was investigated. the diffusion and transport of toluene throug...

One of the main goals of multibody dynamics research is to develop formulations that automatically derive the equations of motions for complex mechanical systems. Equations of motion are formulated systematically and then solved numerically. This paper studies analytic methods for formulating the equation of motions, with emphasis on the graph theoretic modelling approach. The graph theoretic a...

OBJECTIVES This research aimed to evaluate the repercussions of specific chest physiotherapy procedures in mean airway resistance and in dynamic compliance in preterm infants in mechanical ventilation. METHODS Eighteen preterm infants in conventional mechanical ventilation were submitted to one session of chest physiotherapy (manual chest compression during expiration + intermittent aspiratio...

a new mechanical cultivator was proposed for mechanical weeding in part one. the precise point method was used to geometric design of this new cultivator. the aim of this research is selecting the suitable mechanism of the studied mechanisms in part one. the velocity and acceleration of links (kinematic) is the base of dynamic analysis of the systems. the variation of velocity, acceleration and...