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Aims: Bioproduction methods of nanoparticles are preferrabale to chemical and physical methods because of low energy and time expenditure. The aim of this study was to investigate the biological preparation of silver nanoparticles, using Artemisia sieberi.
Materials & Methods: In this experimental study, the extract of Artemisia sieberihas was used to produce silver nanoparticles by a simple, non-toxic, and low-cost method. Formation of silver nanoparticles was established despite the presence of an absorption peak at 490nm, using spectrophotometer. The size and shape of silver nanoparticles were shown using scanning electron microscopy. Precise size and change range of nanoparticles were measured by Particle Size Analysis (PSA). FT-IR results also indicated the role of different functional groups in the synthetic process.
Findings: The change in the color of the extract from pale yellow to light brown and absorption peak at about 490nm showed production of silver nanoparticles. The silver nanoparticles were mainly spherical and their diameter was in the range of 27nm to 65nm, and in some regions, they were stacked or scattered together. The mean size of nanoparticles was 70nm and the dispersion of nanoparticles was in the range of 40nm to 140nm.
Conclusion: The silver nanoparticles derived from the Artemisia are spherical and their mean size is about 70nm. Their dispersion is between 40nm and 140nm.

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In the present work the dynamic response of laminated composite beam reinforced with nano-particles has been investigated. Most of the existing works on the effects of nano-particles on stiffness of the composite structures are limited to very low weight fraction, around 3% to 5%. This work studies the effect of higher percent of Nano particles (up to 10%) on the dynamic behavior of the composite structures via experimental tests. Adding Nano clay up to 3% of weight fraction increases the natural frequency, beyond that up to 5 % the natural frequency slightly decreases and at 10% a sharp reduction in natural frequency is observed. Another feature of importance is the increasing damping coefficient of laminated beam when the amount of nano-particles reaches to 10%.