Visible spectrophotometry is used to study the kinetics of ligand exchange in the system Ni(salpn)/H2salen with or without triethylamine (NEt3) and H2O in dimethylformamide (DMF) solvent at 25 ± 0.1 °C and 0.01 M NaNO3 [H2salen and H2salpn are N,N’-ethylen-bis(salicylaldimine) and N,N’-propylen-bis(salicylaldimine), respectively]. It was found that the reaction rate is of the first-order with r...

in this paper, the measurement of the viscosity of zno in ethylene glycol, propylene glycol, mixture of ethylene glycol and water (60:40 by weight), and a mixture of propylene glycol and water (60:40 by weight) and the thermal conductivity in ethylene glycol and propylene glycol as base fluids in the range of temperature from 25 ºc to 60 ºc are investigated. the results indicate that as the tem...

Heterocyclen, die Elemente der Gruppen 13 und 15 enthalten, wie z. B. Borazine, sind ein fester Bestandteil organischen, biomedizinischen Materialchemie. Überraschenderweise P Al selten. Wir haben nun Phosphaalumene in Reaktionen mit Alkinen, Alkenen konjugierten Doppelbindungssystemen eingesetzt. Mit sterisch anspruchsvollen Alkinen wurden 1,2-Phosphaalumete erhalten, während Reaktion HCCH ode...

ethylene affects the ripening of fruits and is naturally produced in most plant tissues. its production and accumulation during storage can cause serious damage to stored fruits such as black sweet cherries (cv: takdaneh mashhad). it affects shelf-life and can cause a marked increase in respiration rates, increasing ripening and senescence. in some commodities, accelerated aging and the initiat...

bis(indenyl)zirconium dichloride as a catalyst was synthesized using a modified method at the room temperature. polymerization of ethylene and copolymerization of ethylene and propylene were carried out by this metallocene catalyst. ethylene propylene (p/e) feed ratios of 0.25, 0.5, 1, and 2 were employed into the copolymerization systems. copolymerization conditions like cocatalyst/catalyst ra...

background: the risk of multiple pregnancies often present in programs of in vitro fertilization (ivf) is an important force for embryo cryopreservation. on the other hand ethical restriction and assurance of potential fertility following chemo/radio therapy has led scientists to focus on female gamete preservation. objective: optimizing vitrification protocol by using less concentrated cryopro...