An extremely facile and efficient procedure which has been developed for the synthesis of dihydropyrrol-2-ones. One-pot four-component reaction of amines, dialkyl acetylenedicarboxylates and formaldehyde in the presence of N,N,N,N-tetramethylguanidinium acetate [TMG][Ac] in methanol at ambient temperature provides substituted dihydropyrrol-2-ones in good to high yields. The important aspects of...

This paper investigates the amount of doping concentration in silicon semiconductor using optical principle.  Both donor and acceptor impurities of n type and p-type silicon semiconductor materials are computed at wavelength of 1550 nm. During the computation of donor and acceptor impurities, both reflection and absorption losses are considered. Theoretical result showed that transmitted intens...

In practice, the supplier often offers the retailers a trade credit period M and the retailer in turn provides a trade credit period N to her/his customer to stimulate sales and reduce inventory. From the retailer’s perspective, granting trade credit not only increases sales and revenue but also increases opportunity cost (i.e., the capital opportunity loss during credit period) and defau...

the purpose of this survey was the study of the occurrence of anxiety and depression symptoms in patients with type 2 diabetes mellitus with regard to sex and body mass index (bmi). 333 individuals with type 2 diabetes mellitus participated in the study. their demographic and clinical features were examined. the self–completed questionnaire ηads was used for anxiety and depression level evaluat...

we studied the role of nutrients on various aspects of the periphyton community in artificialstreams. dry mass, ash-free dry mass, chlorophyll a and biovolume of the periphyton community weremeasured under 3 different nutrient regimes, including one from natural streams as a control and twowhich were enriched with n and n+p. results of this experiment indicate that the standing crop of theperip...