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A hydrolytic transformation study was conducted in water of pH 4.0, 7.0 and 9.2 to evaluate the effect of pH on persistence of a new readymix formulation of fomesafen and quizalofop-ethyl. The water samples were fortified at 0.5 and 1 µg mL−1 levels and analysed at 0 (2 h), 1, 3, 7, 15, 30, 60, 90, 120, 150 days interval. Both the analytical methods were validated following SANTE guideline and found accurate based on average recovery of 80–100%, Relative standard deviation (RSD)

Compressible Navier–Stokes equations are solved using a fifth-order upwind scheme in the AUSM+ framework to visualize a compressible vortex ring generated from a shock tube. The ring impinges on a wall kept near the open end of the tube. The vortex ring has an embedded shock, counter rotating vortex rings ahead of it and a number of small-scale shear layer vortices trailing behind. When this complex configuration impinges on a wall, wall vorticity is lifted and begins to interact with the complex system of vortices. The paper focusses on the features of the resulting flow field by visualizing them on increasingly finer grids. It is shown that though the different grids capture a fairly matching description of the initial turbulent vortex system that propagates towards the wall, small differences existing between them magnify with time. During vortex–wall interaction, some key experimentally observed features are identified on all the grids, but the details of the vortical structure look significantly different on different grids.

We solve the Euler equations to simulate a cylindrical blast wave in an enclosure. The blast is initiated close to the bottom wall of a square enclosure. An initial Mach 10 shock wave moves into ambient air, causing a mushroom structure behind the shock. We relate the development of this structure to the passage of the reflected shock from the bottom wall through the core of low-density air, which appears to trigger the Richtmyer–Meshkov instability. Use of a ninth-order derivative formula with a four-stage third-order Runge–Kutta time stepping scheme allows us to visualize the vortical motion at the core of the blast in great detail, including the spikes of ambient air penetrating the blast core and two symmetric trails of small-scale vortices behind the primary vortices.