This work reports the fabrication of a nanocomposite using carbon dotdeposited γ-FeOOH/polypyrrole composite through a facile in situ growth of γ-FeOOH, polymerization of pyrrole, and deposition of carbon dots (CDs) in a single pot along with its application as a photocatalyst toward degradation of antibiotics under sunlight irradiation. Here, the expired pharmaceutical drugs (waste) were used as a source of the synthesis of CDs to realize a "waste-to-wealth" approach. A series of nanocomposites (PFL/CDs-x; x = 1, 2, 3, and 4) with different γ-FeOOH content have been synthesized, and their photocatalytic activity was studied. Among all composites, PFL/CDs-2 exhibited the highest degradation efficiency of 97% within 90 min. The optimized γ-FeOOH and CD content in PFL/CDs-2 enhanced light trapping, charge separation, surface area, and formation of distinct heterojunction, indicating it as a promising candidate in photocatalysis. The excellent photocatalytic activity of PFL/CDs-2 can be attributed to synergistic enhancement of the light harvesting due to slow photon effect of the γ-FeOOH nanosheet and the inhibited recombination rate of photoexcited charge carriers based on a Z-scheme photocatalytic mechanism. In addition, the antibacterial potential of the synthesized nanocomposite was studied against Bacillus pumilus (Grampositive) and Escherichia coli (Gram-negative) bacteria. Moreover, the PFL/CDs-2 composite was found to be magnetically separable and recycled without a significant loss of photocatalytic efficiency after four cycles, indicating the high reusability and stability of the photocatalyst.

A three-dimensional multiphase, physics-based model based on large eddy simulation methodology was used to investigate a model shrub fire at a statistically stationary state. Governing equations of the solid phase were modified to achieve this state at which a detailed analysis of the flame and plume is possible through time averaging. The computations were performed for shrub bulk densities ranging from 1 to 6 kg/m 3 and corresponding time-averaged flame heights were recorded. The continuous flame zone, intermittent flame zone and thermal plume region were identified. It was found that flame height scales as the two-fifth power of heat release rate for a mean flame tip temperature of 800 K. The slopes of temperature and velocity profiles along the centerline in the continuous and thermal plume region were consistent with the corresponding slopes for buoyant diffusion flames over porous burners.First-order and second-order statistics were investigated and it was found that there is a strong correlation between velocity and temperature in the continuous flame region. This was attributed to the strong buoyancy accelerations due to combustion of pyrolysis gases from the shrub. Investigation of vortical structures formed in the fire plume showed that strain dominates the flow in the continuous flame region with large scale vortices forming downstream in the plume region.The purely buoyant turbulent fire plume has been an important topic of study in fire 2 science. These type of flows are of interest due to their practical applications in wildland 3 fires, building fires, and the design of fire-prediction tools and fire-protection systems. Many 4 theories, experiments, and simulations have been performed to understand purely buoyant 5 turbulent fire plumes from different types of fire sources, and various correlations have been 6 proposed for flame height, temperature and velocity profiles, air entrainment, etc. 7 Some of the earliest analytical works on fire plumes were carried out by Morton [1] and 8 Nielsen [2] by accounting for temperature and density changes within the plume, energy 9 released by combustion, air entrainment and heat lost due to radiation. The simplified 10 conservation equations were numerically integrated to predict variations in temperature, 11 velocity and plume width along the plume axis. 12 Extensive research has been carried out to study fire plumes from pool fires [3][4][5][6][7][8][9][10][11][12], where 13 correlation have been proposed for flame height and heat release rate. The entrainment rate 14 into the fire plume is characterized, and the different regions in a fire plume, i.e., continuous, 15 intermittent and plume region have been identified. Various fluid mechanical characteristics 16 such as puffing phenomena were studied as well. 17While fire plume in the context of experimental pool fires has a steady rate of fuel sup-18 ply, fire plumes in the context of vegetative fuels are unsteady. Several attempts have been 19 made to characterize the properties of flames from wildl...

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