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The study focused on the production of the tyrosinase enzyme from Streptomyces sp. MR28 and its potency in removal of phenol content from water using free and immobilized tyrosinase enzyme. The tyrosinase was produced by Streptomyces sp. MR28 in liquid tyrosine broth medium, and it was further purified to near its homogeneity by employing, precipitation, dialysis, and column chromatography. After the purification, 44.49% yield with a 4 fold purification was achieved. The characterization of the purified enzyme showed a single major peak on HPLC and a solitary band on SDS-PAGE. The purified tyrosinase enzyme was active at a pH of 7.0 and a temperature of 30 °C. Further immobilization of purified tyrosinase was performed using the sodium alginate entrapment method. The capacity of the purified tyrosinase to remove phenol in water was evaluated by spectrophotometric method. The free tyrosinase enzyme-treated solutions showed a gradual decrease in the concentration of phenol with increased incubation time at 30 °C and 40 °C, at 90 min of the incubation time, it showed maximum efficacy in removing phenol from the solution. At 50 °C and 60 °C, the free tyrosinase enzyme exhibited very less capacity to remove the phenol. The immobilized enzyme showed good capacity for the removal of phenol from the solutions; the concentration of phenol in the solution decreased with an increase in the incubation time. At temperatures of 40 °C and 50 °C, the immobilized tyrosinase enzyme beads showed significant removal of phenol from the solution, and at temperatures of 30 °C and 60 °C, they also exhibited good capacity for the removal of phenol. At the end of the 90 min incubation period, it exhibited good capability. The current study suggests using immobilized microbial tyrosinase enzyme can be used for the removal of phenol from the contaminated water in a greener manner. • Tyrosinase was produced from Streptomyces sp. MR28 in modified tyrosine broth with optimum conditions. • The purification was conducted through precipitation, dialysis and column chromatography. • The purified tyrosine enzyme characterized by SDS-PAGE and HPLC analysis. • Purified tyrosinase was immobilized using sodium alginate method. • The immobilized tyrosinase exhibited significant phenol removal efficacy from water. [ABSTRACT FROM AUTHOR]

A computational fatigue study of the propagation of delamination in a composite wing rib has been conducted. A typical Boeing 747 rib having a circular hole with a semi-elliptical delamination was taken as the rib of interest; gust loads experienced during the cruise phase of flight were identified as the source of fatigue. A square section surrounding the circular hole comprising of laminated carbon–epoxy prepreg was isolated from the rib for computational analysis. The lack of analytical solutions for such a problem encouraged the use of the general-purpose finite element software ABAQUS. The delamination mechanism was simulated using the energy-based virtual crack closure technique in tandem with the Paris–Erdogan equation. The delamination propagation with respect to aircraft flight hours was obtained for the aircraft rib, with Mode III tearing dominating the delamination process. A parametric analysis was further conducted for various ply orientations where delamination modes were compared via a frame-based analysis. Significant differences in delamination propagation were observed, and better performing orientations for the given conditions were identified. [ABSTRACT FROM AUTHOR]