Acoustics and thermal studies of conventional heat transfer fluids mixed with ZnO nano flakes at different temperatures.

The present investigation is mainly focused upon the effect of adding zinc oxide nano particles in the conventional heat transfer fluid involving the mixture of ethylene glycol & water (EG-water). Efforts have been made to synthesize zinc oxide nano particles by precipitation technique and to blend with EG-water to prepare nanofluids using ultrasonication. From the characterization, the shapes of the particles were found to be agglomerated nano flakes. The ultrasonic velocity and transport properties have been measured to characterize the nanofluids and they also shed light on the molecular environment of the dispersed phase at different temperatures. The dynamic viscosity shows the nanofluids to be non-Newtonian fluids at very less shear rate. In addition, the stability of the nanofluid is being interpreted from UV-visible study.

Multicomponent synthesis of spiropyrrolidine analogues derived from vinylindole/indazole by a 1,3-dipolar cycloaddition reaction.

A new series of spiropyrrolidine compounds containing indole/indazole moieties as side chains have been accomplished via a one-pot multicomponent synthesis. The method uses the 1,3-dipolar cycloaddition reaction between N-alkylvinylindole/indazole and azomethine ylides, prepared in situ from cyclic/acyclic amino acids. The 1,3-dipolar cycloaddition proceeds efficiently under thermal conditions to afford the regio- and stereospecific cyclic adducts.