Yuko Morito

Fabrication of a TiO2 nanoparticles impregnated titanium mesh filter and its application for environmental purification

A novel photocatalytic filter, titanium-mesh sheet modified with TiO2 (TMiP), was fabricated and applied for environmental purification. The high flexibility of TMiP allows for an easy to design and fabricate photocatalytic reactor. Moreover, TMiP provides an excellent air or water pass-through while maintaining a high level of surface contact with UV irradiation.

Development of an O3-assisted photocatalytic water-purification unit by using a TiO2 modified titanium mesh filter

An ozone-assisted photocatalytic water-purification unit using a TiO2 modified titanium-mesh sheet (TMiP) was investigated. Significant decomposition of biological and chemical contaminants has been achieved by highly active intermediates formed by catalytic decomposition and photocatalysis.

Compact and effective photocatalytic air-purification unit by using of mercury-free excimer lamps with TiO2 coated titanium mesh filter

A photocatalyst–excimer–lamp hybrid reactor was investigated using a mercury-free xenon chloride excimer lamp wrapped with a TiO2 modified titanium-mesh sheet (TMiP). Significant decomposition of 6 ppm of methylmercaptane gas has been achieved by the reactor in a 36 L box within 3 h.

Field performance test of an air-cleaner with photocatalysis-plasma synergistic reactors for practical and long-term use.

A practical and long-term usable air-cleaner based on the synergy of photocatalysis and plasma treatments has been developed. A field test of the air-cleaner was carried out in an office smoking room. The results were compared to previously reported laboratory test results. Even after a treatment of 12,000 cigarettes-worth of tobacco smoke, the air-cleaner maintained high-level air-purification activity (98.9% ± 0.1% and 88% ± 1% removal of the total suspended particulate (TSP) and total volatile organic compound (TVOC) concentrations, respectively) at single-pass conditions. Although the removal ratio of TSP concentrations was 98.6% ± 0.2%, the ratio of TVOC concentrations was 43.8% after a treatment of 21,900 cigarettes-worth of tobacco smoke in the field test. These results indicate the importance of suitable maintenance of the reactors in the air-cleaner during field use.

Development of a flexible γ-ray detector using a liquid scintillation light guide (LSLG)

A flexible γ detector using a liquid scintillation light guide (LSLG) was developed. The analyzed pulse height (PHA) spectrum depended on the diameter, length and scintillator concentration of the LSLG, and the distance of a γ ray irradiation point from the head of photomultiplier tube (PMT). From the analysis of PHA spectrum, it was found that the count ratio of two divided channel regions linearly decreases as the distance from the PMT head increases. It was further found that the radiation dose rate can be estimated by setting the flexible LSLG tube to a circular shape since the count rate is proportional to the dose rate measured by a conventional NaI (Tl) scintillation detector. Therefore, a flexible and long LSLG detector using a single PMT is useful for determination of the dose rate and has a potential to detect local contaminations in a certain narrow space.