An efficient sodium bismuthate (NaBiO3) synthesis of biologically active spiro[4H-pyran]derivatives has been accomplished via one-pot three-condensation of isatin/acenaphthequinone, malononitrile and different reagents including 1,3-dicrbonyl compounds, α-naphthol and 4-hydroxycumarin under solvent-free conditions. The notable advantages of the present procedure are: eco-friendly, environmental...

A simple, clean, and environmentally benign three-component process for the synthesis of 2-amino-4Hchromenes using [mim]Cl, as an efficient catalyst under solvent-free conditions are described. A wide range of aromatic aldehydes easily undergoes condensations with 1-naphthol and malononitrile under solvent-free conditions to afford the desired products of good purity in excellent yields. Taking...

Investigations were carried out to evaluate the performance of direct injection diesel engine with medium grade low heat rejection (LHR) combustion chamber and 3 mm air gap insulated piston, 3 mm air gap insulated liner, and ceramic coated cylinder head [ceramic coating with the thickness of 500 µ was made on the inside portion of the cylinder head].The engine had different operating conditions...

Abstract Methane and coal dust explosions are among the most common causes of disasters in hard mining. Therefore, it is important for occupational safety mines operating under methane explosion hazards to identify possible ignition sources, whether due natural or technical factors. One source can be mechanical sparks generated during operation equipment high surface temperatures components ope...