Kinetic modeling of ZnO-rGO catalyzed degradation of methylene blue

Photodegradation of organic pollutants strongly depends on design of metal oxide semiconductor photocatalysts. Graphene, if composited with ZnO, can effectively enhance its photocatalytic performance for the eradication of pollutants from aqueous medium. Here in, ZnO-rGO is reported as highly active catalyst for degradation of methylene blue. A 200-mg/L solution of methylene blue dye was completely degraded within 1 h in comparison to 74% and 56% degradation over ZnO and rGO, respectively. The commonly used mechanisms of heterogeneous catalytic reactions, the Langmuir-Hinshelwood mechanism, and the Eley-Rideal mechanisms, were used to describe the reaction kinetics. The Langmuir-Hinshelwood mechanism was found as more favorable in this study. Apparent activation energy, E_ap, true activation energy, E_T, entropy, ΔS, and enthalpy, ΔH were calculated as 36.2 kJ/mol, 13.1 kJ/mol, 197.5 J/mol, and 23.1 kJ/mol, respectively.     

Entropy generation analysis of tangent hyperbolic fluid in quadratic Boussinesq approximation using spectral quasi-linearization method

Applied Mathematics and Mechanics - In many industrial applications, heat transfer and tangent hyperbolic fluid flow processes have been garnering increasing attention, owing to their immense...     

Enhanced production of xylanase from locally isolated fungal strain using agro-industrial residues under solid-state fermentation

This study is related to the isolation of fungal strain for xylanase production using agro-industrial residues. Forty fungal strains with xylanolytic potential were isolated by using xylan agar plates and quantitatively screened in solid-state fermentation. Of all the tested isolates, the strain showing highest ability to produce xylanase was assigned the code Aspergillus niger LCBT-14. For the enhanced production of the enzyme, five different fermentation media were evaluated. Out of all media, M4 containing wheat bran gave maximum enzyme production. Effect of different variables including incubation time, temperature, pH, carbon and nitrogen sources has been investigated. The optimum enzyme production was obtained after 72 h at 30°C and pH 4. Glucose as a carbon source while ammonium sulphate and yeast extract as nitrogen sources gave maximum xylanase production (946 U/mL/min). This study was successful in producing xylanase by A. niger LCBT-14 economically by utilising cheap indigenous substrate.     

Ab-initio calculations of structural,electronic,and optical properties of Zn_3(VO_4)_2

The structural, electronic, and optical properties of Zn_3(VO_4)_2 are investigated using full potential linearized augmented plane wave(FP-LAPW) method within the framework of density functional theory(DFT). Various approaches are adopted to treat the exchange and correlation potential energy such as generalized gradient approximation(GGA),GGA+U, and the Tran–Blaha modified Becke–Johnson(TB-mBJ) potential. The calculated band gap of 3.424 eV by TB-mBJ is found to be close to the experimental result(3.3 eV). The optical anisotropy is analyzed through optical constants,such as dielectric function and absorption coefficient along parallel and perpendicular crystal orientations. The absorption coefficient reveals high absorption(1.5 × 10~(6) cm~(-1)) of photons in the ultraviolet region.     

Certain fractional calculus and integral transform results of incomplete ℵ-functions with applications

In this paper, we study certain interesting and useful properties of incomplete $\aleph$-functions. The incomplete $\aleph$-function is an extension of the $\aleph$-function. We find several useful classical integral transforms of these functions. Further, we examine the fractional calculus with the incomplete $\aleph$-functions and point out several special cases. Finally, we give the applications of incomplete $\aleph$-functions in detecting glucose supply in human blood.     

Caragisides A – C,New Isoflavone Glucosides from Caragana conferta with Inhibition of Platelet Aggregation

Caragisides A–C ( 1 – 3 , resp.), three new isoflavone glucosides, were isolated from the BuOH sub‐fraction of the EtOH extract of the whole plant of Caragana conferta, along with ononoside ( 4 ), reported for the first time from this species. The structures of the new compounds were elucidated by spectroscopic techniques including MS and 2D‐NMR spectroscopy. Compounds 1 – 3 showed significant inhibition of platelet aggregation.