A detailed analysis has been performed for a heterogeneous photocatalytic Taylor vortex reactor that uses flow instability to recirculate fluid continually from the vicinity of the rotating inner cylindrical surface to the stationary outer cylindrical surface of an annulus. In the present research, a detailed time-accurate computation shows the different stages of flow evolution and the effects of the finite length of the reactor in creating eddies, which results in a very high overall efficiency of photocatalytic conversion. The physical arrangement considered is such that pollutant degradation is maximized by the motion of fluid particles in a specific regime of centrifugal instability. Also provided are detailed flow structures for the chosen parameters when the reactor is started impulsively.

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Heterogeneous photocatalysis, as a technology for wastewater treatment, is a very attractive approach for treating low-concentration, high-volume fluids. The design and development of an appropriate photocatalytic reactor for conducting photocatalysis requires a study of the hydrodynamics of the reactor coupled with the intrinsic rate kinetics to achieve higher quantum yields and optimum photocatalyst requirements. An annular dual-function photocatalytic reactor operating in absorption (fixed-bed) and regeneration (fluid-bed) modes was constructed for the purpose of this study. A technique using radioactive particle and two γ-ray cameras arranged perpendicularly to each other was used successfully to study the fluidized-bed behavior. This three-dimensional radioactive particle tracking (RPT) approach can enable the prediction of the amount of UV light a particle would receive during illumination, which decides the production rate of hydroxyl radicals and, in turn, the reaction rates. Also, CT scanning of the bed at various superficial velocities provides a tool for reliably and accurately predicting the bed voidage in a particular region of interest. Degradation experiments of model pollutant (phenol) were conducted with a pilot-scale reactor to evaluate its effectiveness. Adsorption of pollutant onto the catalyst and pollutant degradation with respect to various catalyst loadings were investigated. The economic viability of the reactor in comparison with other existing technologies is discussed in this paper.

In eukaryotic cells, the aggregation of the endoplasmic reticulum (ER)-mediated unfolded or misfolded proteins leads to disruption of the ER homeostasis, which can trigger ER stress. To restore the ER homeostasis, the ER stress activates the intracellular signaling cascade from the ER to the nucleus, referred to as the unfolded protein response (UPR). Autophagy primitively portrayed as an evolutionarily conserved process is involved in cellular homeostasis by facilitating the lysosomal degradation pathway for the recycling and elimination of intracellular defective macromolecules and organelles. Autophagy is tightly regulated by the protective mechanism of UPR. The UPR and autophagy are interlinked, which indicates that the ER stress can not only induce autophagy but also suppress it. Here, we discuss the molecular mechanism of ER stress and autophagy and their induction and inhibition signaling network.

Laboratory and small pilot scale fluidized bed photoreactors are described that utilize an integrated photocatalyst adsorbent (IPCA) mounted on porous silica beads as support protecting against IPCA attrition. The active material is Degussa P-25 TiO 2 bound to a Silicalite I zeolite adsorbent. Operating conditions for fluidization that achieves uniform illumination of photoactive particles are determined. Axial and multi-lamp configurations are compared. The small pilot reactor is calibrated against the laboratory reactor. Sub-stoichiometric acceleration of phenol oxidation by H 2 O 2 was observed.