statement of problem: for many years, application of the composite restoration with a thickness less than 2 mm for achieving the minimum polymerization contraction and stress has been accepted as a principle. but through the recent development in dental material a group of resin based composites (rbcs) called bulk fill is introduced whose producers claim the possibility of achieving a good rest...

Efficient utilisation of renewable biomass resources, particularly lignocellulosic biomass, for the production of chemicals and fuels has attracted much attention in recent years. The catalytic conversion of cellulose, the main component of lignocellulosic biomass, selectively into a platform chemical such as glucose, 5-hydroxymethyl furfural (HMF), sorbitol or gluconic acid under mild conditio...

Two new cantilever-type polyoxometalates Na(5)(NH(4)){V(IV)[(Mo(2)O(6))CH(3)C(O)(PO(3))(2)](2)}.13H(2)O (1) and (NH(4))(4){V(IV)[(Mo(2)O(6))NH(3)CH(2)CH(2)CH(2)C(O)(PO(3))(2)](2)}.6H(2)O (2) have been synthesized and characterized by IR spectroscopy, UV-visible spectroscopy, elemental analysis, TG analysis, XPS, (31)P NMR and single-crystal X-ray diffraction. The structure analysis reveals that...

in this study , the physical and mechanical properties of polypropylene composites reinforced with bagasse alkaline-sulfite-anthraquinone, soda-anthraqouinone, monoethanolamine-anthraquinone chemical pulps and mechanical pulp (cmp) known as pulp-plastic compostes (ppc) were investigated and the results were compared among ppcs and with polypropylene composites reinforced with bagasse flour know...

this study was conducted to investigate the effects of applying methods andamount of ammonium polyphosphate (0, 2 and 4 wt%) on fire retardancy andmechanical properties of wood flour/polypropylene composites. the resultsshowed that addition of fire retardant improved the mechanical properties such astensile and flexural strengths and fire retardancy of composites. but by increasingof fire retar...

most impact tests are carried out on specimens with specific stacking sequence and dimensions to meet standard and experimental limitations. the damaged areas and the resulted reduction in the strength values of specimens may not agree very well with those of real application. in this paper an attempt is made to study the variation in the size of damaged areas due to varying the dimension of te...