in some special cases, rubber compounds with high amounts of unsaturated elastomer are recommended with organic sulfur donors instead of mineral sulfurs. in this condition, activated sulfur is produced in situ and curingprocess is facilitated without accelerators. organic sulfur donor compounds have low thermal stability and in the vulcanization temperature produce free and activated sulfurs. t...

A new series of betulin derivatives containing one or two pharmacophores bearing an acetylenic and carbonyl function at the C-3 and/or C-28 positions has been synthesized and characterized by ¹H- and ¹³C-NMR, IR, MS and elemental analyses. The crystal structure of 28-O-propynoylbetulin was determined by X-ray structural analysis. All new compounds, as well as betulin, were tested in vitro for t...

The energetic and electronic properties of acetylenic-bond-interconnected hexagonal boron nitride sheets (BNyne), in which the number of rows of BN hexagonal rings (denoted as BN width) between neighboring arrays of acetylenic linkages increases consecutively, have been explored using first-principles calculations. Depending on the spatial position of B/N atoms with respect to the acetylenic li...

This is not breaking news: copper acetylides, readily available polymeric rock-stable solids, have been known for more than a century to be unreactive species and piteous nucleophiles. This lack of reactivity actually makes them ideal alkyne transfer reagents that can be easily activated under mild oxidizing conditions. When treated with molecular oxygen in the presence of simple chelating nitr...

the adsorption properties and mechanics of selected endocrine disrupting compounds; 17 β-estradiol, 17 α – ethinylestradiol and bisphenol a on locally available black tea leaves waste and granular activated carbon were investigated. the results obtained indicated that the kinetics of adsorption were ph, adsorbent dose, contact time and temperature dependent with equilibrium being reached at 20 ...