Biomedical subjects

Takeshi Ogata

Publications and source records attributed to Takeshi Ogata.

3 recordsLinked to original sources

PubMed2005

Mechanisms of gold recovery from aqueous solutions using a novel tannin gel adsorbent synthesized from natural condensed tannin.

We report a novel recovery system for gold (Au), which is one of the precious metals contained in electronic scrap, utilizing tannin gel particles. Tannin gel particles were prepared by a process of cross-linking of condensed tannin (wattle tannin), which is a ubiquitous and inexpensive natural material having many hydroxyl groups. The adsorption mechanism of gold onto tannin gel particles was elucidated: the adsorption of gold takes place through the reduction of trivalent gold ions to metallic gold on the surface of tannin gel particles, which is accompanied by the simultaneous oxidization of the hydroxyl groups of tannin gel. Additionally, the adsorption capacity of gold was found to be extremely high, 8000 mg-Au/g-dry gel. The outstanding characteristics of tannin gel particles for gold offers the possibility of efficient recovery of other precious metals.

Adsorption↗

PubMed2004

A lattice kinetic scheme for bubble flows.

A lattice kinetic scheme for two-phase immiscible fluids with large density ratios is presented. The difficulty in the treatment of large density ratio is resolved by using the projection method. The method can simulate two-phase fluid flows with a density ratio up to 1000. The method is applied to the simulation of many bubbles rising in a long square duct. The complicated unsteady structures of the interface and the velocity field can be simulated in a stable manner.

Journal Article↗

PubMed2003

[Possibility for the presence of Helicobacter pylori in drinking well water].

Forty three well waters which are currently used as drinking water were studied for the presence of Helicobacter pylori. Using magnetic-beads purification and PCR amplification of H. pylori-specific gene, 4 of the 43 samples were positive for H. pylori-ureA gene (9.3%) and 1 of the 43 samples was positive for H. pylori-16SrRNA gene (2.3%). The presence of H. pylori-specific amplified product did not correlate with the type, depth and location of the wells. This study demonstrated that H. pylori can be transmitted via drinking water, especially well water in Japan.

Helicobacter pylori↗