The Ru/CeO₂ (JRC-CEO-3) catalyst prepared by NaBH₄ reduction showed a high activity for NH₃ decomposition compared with the other catalysts prepared in this work; however, this catalyst gradually lost its activity due to the accumulation of adsorbed species produced during the reaction. Cs significantly improved the catalytic performance of the Ru/CeO₂ catalyst, and the optimum Cs/Ru molar ratio was 0.4 because excess Cs species gradually covered the exposed Ru metal active sites. Cs–Ru/CeO₂-0.4 catalyzed the NH₃ decomposition reaction without H₂ pretreatment because the catalyst was activated by NH₃ or H₂ produced by NH₃ decomposition. Moreover, Cs not only increased the N–H bond dissociation rate but also decreased the effect of the H₂ partial pressure on the catalytic performance. Consequently, the Cs–Ru/CeO₂-0.4 catalyst exhibited a high, stable activity (NH₃ conversion: 92% at 623 K and 60% at 573 K) with a gas hourly space velocity of 2000 mL-NH₃ g-cat⁻¹ h⁻¹.

The application of induced pluripotent stem (iPS) cells holds significant promise for regenerative medicine and drug screening. To produce sufficient quantities of high-quality iPS cells in undifferentiated form, a wave bioreactor has been widely used for static cell cultivation. A systematic optimization of shear stress and cell dispersion has been conducted using numerical simulation, as it is a powerful tool for obtaining accurate predictions in aggregated cell cultivation. In this study, the cells are modeled as rigid spherical particles initially distributed at the center of a square vessel. The simulation results indicate that the shear stress acting on the particles is proportional to the shaking speed and angle caused by the strong velocity gradient. Meanwhile, the characteristics of particle dispersion indicate that the particles are distributed efficiently in the whole tank under a larger shaking angle. An optimal condition for cell cultivation is proposed based on a specific analysis of the controlling parameters associated with the shaking velocity and angle. It is concluded that the numerical model and computer-aided design presented herein are powerful tools for the design optimization of a bioreactor for automated cell cultivation.

In(OH)₃/InOOH nanocrystals are synthesized using InCl₃∙4H₂O as the indium source in the presence of ethylenediamine by a one-step hydrothermal process, and the effect of synthesis temperature on the morphology, crystallization, structure, and photocatalytic properties of the photocatalysts is investigated. The results show that all the synthesized In(OH)₃/InOOH samples have granular nanoparticles with a size of 20–30 nm. When the synthesis temperature is lower than 150°C, only the In(OH)₃ phase exists. With increasing synthesis temperature, In(OH)₃ gradually dehydrates to form InOOH to achieve a phase equilibrium between InOOH and In(OH)₃. The concentration of InOOH is the maximum at 180°C and decreases at 210°C. The photocatalytic activity is evaluated from the degradation of a Rhodamine B solution under ultraviolet light irradiation, which follows the first-order reaction kinetics. The increase in synthesis temperature can significantly improve the photocatalytic performance of In(OH)₃/InOOH because of the formation of a large number of natural heterojunctions in the nanocrystals, which can enhance ultraviolet light absorption and facilitate charge transfer and separation. The first-order kinetic constant of the nanocrystals synthesized at 180°C is almost 2.5 times that of the nanocrystals synthesized at 150°C. The active species capture experiments demonstrate that holes and superoxide radicals are the main active species in the photocatalytic systems.

Copper fine particles were prepared by a wet chemical method using copper sulfate as a starting material, hydrazine as a reducing agent, and sodium hydroxide as a pH adjuster. It was found that there was a branch point at which the precursor changed to copper hydroxide (Cu(OH)₂) or copper oxide (CuO), depending on the sodium hydroxide/copper sulfate molar ratio, and a range in which the particle size of the metallic copper fine particles was minimum. At higher concentrations and feeding rates of the hydrazine solution, smaller copper particles were obtained. Copper particles with a size of 0.14–2.4 µm were obtained at a sodium hydroxide/copper sulfate molar ratio of 0.9–4.9, hydrazine concentration of 2.02–20.2 mol/L, and hydrazine feeding rate of 0.5–1.0 mL/min.

We report the first investigation of biochar production via the solvothermal carbonization of wood chips and poly(vinyl chloride) (PVC) in glycerol. In this process, the dechlorination efficiency of PVC was significantly promoted by the reaction with wood chips or glycerol. When wood chips, PVC and glycerol with a weight ratio of 1 : 1 : 1.5 were heated at 200–260°C in an autoclave, solid products that contained a liquid remained at a temperature below 220°C. When the temperature was increased to 240°C, the liquid product disappeared, and resinified biochar was obtained. Accordingly, the process can be simplified without the need for separation after the carbonization. The biochar yield was 17.3% at 220°C and increased rapidly to 53.6% at 240°C. Similarly, the dechlorination rate was 30% at 220°C and increased to 80% at 240°C. This is attributed to the progress of the epoxy reaction, which was accompanied by dechlorination, in the temperature range of 220–240°C.