To recycle plastics in automobile shredder residue (ASR) is strongly required to reduce the amount of incineration. Using the slight difference in specific gravity of plastics made of different materials and additives, a separator using the difference of settling velocity in water is considered as a promising process. However, a high feed rate in the separator often decreases the recovery or grade of plastics. To contribute to the optimized design of the separator, this research evaluated the effect of a feed rate on the recovery or grade by the discrete element method coupled with computational fluid dynamics. Simulation results showed that as the feed rate increased, the contact number and the residence time of plastics increased, and the floating of plastics was hindered, resulting in a decrease in the recovery rate of the particles.

The objectives of this study are 1) to investigate the effect of silica source concentration on the properties of the silica-coated magnetite nanoparticle (MNP) prepared using the electrooxidation method, and (2) to apply the resulting silica-coated MNP for the immobilization of thermoresponsive copolymer, (poly(NIPAM-co-AA)), which we developed for heavy metal ion recovery. The results of laser diffraction analysis show that the particle size distributions of the silica-coated MNP are smaller than that of the uncoated MNP, which indicates that the aggregation of MNP is suppressed by silica coating. Thermogravimetric analysis (TGA) results show that the immobilized copolymer amount on the silica-coated MNP is approximately 5 times larger than that on the uncoated MNP. These results indicate that the successful suppression of MNP aggregation through silica coating using the electrooxidation method contributes to the increase of the available surface area for the copolymer immobilization.

Dynamic fields visualization method of carbon-black (CB) volume fraction Φ_CB distribution in Lithium-ion battery (LIB) cathode slurry has been proposed based on electrical resistance tomography (ERT) during the manufacturing process. The proposed method consists of an impedance analyzer, a switching circuit, and Φ_CB distribution imaging algorism, archiving to the measurement speed of 5 frames per second. In experiments, Φ_CB distribution was visualized by the proposed method in lab-scale LIB cathode manufacturing equipment. To qualitatively evaluate the Φ_CB distribution images, those images are compared with scanning electron microscope (SEM) images. This comparison shows that the Φ_CB distribution images are qualitatively consistent with SEM images. In addition, in order to quantitatively evaluate the proposed method, the accuracy of reconstructed Φ_CB distribution is evaluated by electromagnetic field simulations. As a result, the root mean square errors RMSE between the known Φ_CB distribution and that obtained by the proposed method was less than 0.56%.

Dry powder inhalers (DPIs) have been widely used to treat respiratory diseases due to the large absorption site in a human lung. Understanding the fluid and particle deposition behaviors from the device to human respiratory system is essential to improve the efficiency of DPIs. In this study, an adhesion model of particles against liquid layer was proposed and relationship between the fluid and the particle behaviors in a pipe represented an oral cavity was analyzed by using numerical simulations. The adhesion force between particles and mucus layer in the oral cavity was calculated with the consideration of impact force, viscosity force and liquid bridge force. The numerical simulations of the particle deposition in the oral cavity revealed that the adhesion force which contributed to tension, capillary and viscosity forces, inertia of particle and particle concentration were dominated as the adhesion in the oral cavity.

The role of hydrodynamic interaction between micron-sized particles on the motion of a single magnetic probe particle, on which an external magnetic force is exerted, is studied. The motion of a probe particle in an index-matched suspension of surrounding particles is investigated using an optical microscope and image analysis technique. When inter-surface distance is smaller than the diameter of probe particle, the velocity of probe particle is reduced but rarely affected by the size of surrounding particles. The reduction of probe particle velocity is well associated with Péclet number of surrounding particles, but the degree of the suppression becomes significant below the critical inter-surface distances. The hydrodynamic interaction becomes many-body problems under the condition, and as a result, the bulk viscosity becomes larger than that under complete dispersion.