Cellulose sulfuric acid as a bio-polymer based solid catalyst efficiently catalyzes the selectively oxidation of sulfides to sulfoxides and thiols to disulfides using hydrogen peroxide as a green oxidant with good yields at room temperature. The developed method offers a number of advantages such as high selectivity, mild reaction conditions, simple operation, cleaner reaction profiles, low...

Nano sulfated titania was tested as solid acid heterogeneous catalyst for the synthesis of 4-(Trifluoromethyl) coumarin and coumarin derivatives under solvent-free condition. Factorial design evidenced a positive effect of reaction temperature, amount of catalyst, and solvents.  This nano-sized sulfated titania has been prepared by a sol-gel hydrothermal process. The prepared sulfated titania s...

17-4ph stainless steel is a martensitic precipitation hardening stainless steel that provides an outstandingcombination of high strength, good corrosion resistance, good mechanical properties, good toughness in both base metal and welds, and short time, low-temperature heat treatments that minimize warpage and scaling. this valuable alloy is widely used in the aerospace, nuclear, chemical, petr...

Electricity generation from renewable energy sources is emerging as a result of global carbon emission reduction policies. However, most are non-dispatchable and cannot be adjusted to meet the fluctuating electricity demands society. A flexible operation process has been proposed an effective solution compensate for unstable nature sources. Thermal load fluctuations during may cause creep–fatig...