This research studies the influence of using SiO2 nano-particles 50nm in a Vapor Compression Refrigeration System (VCRS), along with Poly-alkylene Glycol (PAG) oil and R-134a mixed to create nano-refrigerant. In this work, were performed three different concentrations (0.1%, 0.3%, 0.5%) 200ml PAG oil. AVCR system was built at mechanical engineering department laboratory Al-Qadisiyah University ...

The miscibility of the dicyanate of bisphenol A, with three dicyanate monomers, with aryl/alkylene ether backbones is studied at different compositions of a binary blend. Solubility parameters are calculated for dicyanate monomers and selected oligmers using the methods of Small and Fedors to predict compatibility. The results are evaluated in terms of the accuracy of the model in reproducing o...

This work presents a new synthetic approach to aromatic and aliphatic polycarbonates by melt polycondensation of bisphenol A diacetates with alkylene- and arylenediphenyl dicarbonates. The diphenyl dicarbonates were prepared from phenyl chloroformate and the corresponding dihydroxy compounds. The process involved a precondensation step under a slow stream of dry argon with the elimination of ph...

Application of lipases (preferentially Candida antarctica Lipase B, CALB) for melt polycondensation aliphatic polyesters by transesterification activated dicarboxylic acids with diols allows to displace toxic metal and oxide catalysts. Immobilization the enzyme enhances activity temperature range use. The possibility use enzyme-catalyzed in is studied compared results polycondensations solution...