A UV‐C/titanium dioxide (TiO2) plate coated photocatalytic reactor using a corrugated frame system was designed for water borne organic contaminant degradation. The anticipated advantages of using the corrugated layout include a larger photocatalytic surface area per unit volume and improved photocatalytic activity. The water distribution system was designed to assist effective interactions among the water pollutant, photocatalyst, and photons. The degradation of a methylene blue solution, as a model water contaminant, was carried out at room temperature (22 °C) at different concentrations and flowrates. With an 11 mg/L methylene blue solution, 70 % was degraded within the first 10 min using TiO2 coated corrugated plates, whereas under the same conditions the degradation rate was only 12 % for a corrugated reactor without a catalyst coating, and 4 % for a no‐plate reactor. The methylene blue degradation was described by the Langmuir‐Hinshelwood model, and the apparent photonic efficiency of the corrugated arrangement was found to be in the range of 1.53–2.83 % when half the initial concentration was degraded. The local area specific rate of energy absorption (LASREA) profile over the plates was determined from a model developed based on UV‐C light irradiation distribution and plate configuration. Light intensity measurements were carried out and were found to correlate with this model. A set of corrugated plate photocatalytic reactors with different geometries, but with the same coated area, were then analyzed and absorbed UV light intensities were integrated to determine the best geometry.

Immobilizing the photocatalyst in a water treatment process design is essential; however, the immobilization method may affect the photoactivity of the photocatalyst. In this work, photocatalyst powders were successfully coated on 316 L stainless steel plates by a novel brush coating method. Three combinations of photocatalyst mixtures (pure TiO 2 anatase, anatase doped with WO 3 , or TiO 2 rutile) were and annealed at different temperatures between 460-540 C. The~10 μm thick coatings demonstrated full plate coverage and strong adhesion and adequate durability. Surface roughness increased with annealing temperature. The doping and annealing process enabled band gap reduction to the visible light spectrum for all coatings, with the smallest band gap being 2.48 eV (1 eV = 1.6 × 10 −19 J). Subsequent methylene blue degradation tests under UV-C showed that the coatings annealed in 460 C exhibited the best performance and with the highest degradation rate constant of 5.59 hours −1 . K E Y W O R D Sadvanced oxidation process, annealing, band gap, photocatalyst coatings, roughness

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The role-based access control model (RBAC) is an access control approach oriented to enterprise security policy, which plays a leading role in the field of access control due to its good applicability and flexibility. However, as the scale of access subjects and access objects expands, it becomes more difficult to develop a role engineering system that meets security requirements. Particle size calculation can reduce or improve the particle size of the problem and improve efficiency on the premise of obtaining satisfactory solutions. In this study, the granularity calculation method was introduced into the role formulation process of RBAC, which can effectively reduce the complexity of the problem and improve the efficiency of the RBAC role engineer. At the same time, the concept lattice reduction method was used to reduce the role concept lattice and reduce the workload of the system security administrator.