Elsevier BV Acta Medica Okayama 0022-3093 592 2022 Effect of bond valence sum on the structural modeling of lead borate glass 121751 EN Masaaki Nagao Graduate School of Environmental and Life Science, Okayama University Shinichi Sakida Environmental Management Center, Okayama University Yasuhiko Benino Graduate School of Environmental and Life Science, Okayama University Tokuro Nanba Graduate School of Environmental and Life Science, Okayama University Atsushi Mukunoki JGC Japan Corporation Tamotsu Chiba JGC Japan Corporation Takahiro Kikuchi JGC Japan Corporation Tomofumi Sakuragi Radioactive Waste Management Funding and Research Center Hitoshi Owada Radioactive Waste Management Funding and Research Center The structural model of 66.7PbO-33.3B2O3 glass was constructed using a reverse Monte Carlo (RMC) method, in which bond valence sum (BVS) was added as a constraint condition to suppress formation of unrealistic local structures. Based on the crystal structures, the optimal BVS calculating conditions were determined. As a result, BVS distributions with small deviation were successfully achieved without lowering the reproducibility of other experimental constraints. The geometric asymmetry of PbOn polyhedra was evaluated from the eccentric distance between Pb and gravity center of oxygen atoms. The average eccentric distance was shorter than that in the lead borate crystals, indicating less asymmetry of PbOn units in the RMC glass model. The connectivity between BOn and PbOn units was investigated. It was consequently concluded that the glass had a different network structure from the crystal with the same composition, which might be due to the different chemical bonding character between the lead borate glasses and crystals. No potential conflict of interest relevant to this article was reported.

Ceramic Society of Japan Acta Medica Okayama 1348-6535 130 8 2022 Environmental activities on glass in Japan 605 610 EN Tokuro Nanba Graduate School of Environmental and Life Science, Okayama University Yasuhiko Benino Graduate School of Environmental and Life Science, Okayama University Tomoko Akai National Institute of Advanced Industrial Science and Technology (AIST) In general, glass has been recognized as an environmentally friendly material. However, the production of glass requires a lot of heat energy, and the raw materials also emit CO2 at the melting process. In fact, commercial glasses are not easy to recycle. In glass industry of Japan, various efforts have been made so far to reduce the environmental impact of glass. In this paper, not only glass manufacturing technologies but also glass recycling technologies were reviewed, and the future glass production technologies to achieve carbon neutrality were also introduced. No potential conflict of interest relevant to this article was reported.

岡山大学環境管理センター Acta Medica Okayama 0917-1533 37 2016 平成27 年度環境管理センター公開講演会「地球温暖化と気候変動が関わるリスク」 3 15 EN Yasuhiko Benino No potential conflict of interest relevant to this article was reported.

岡山大学環境理工学部 Acta Medica Okayama 2187-6940 19 1 2014 分子軌道計算による高い離型性を有するセラミックスコーティングの材料設計 22 25 EN Tokuro Nanba Jiro Fujihara Shinichi Sakida Yasuhiko Benino 10.18926/fest/52229 　To explore the ceramic materials appropriate for the coatings with high mold releasability, molecular orbital (MO) calculations have been applied to the ceramics with NaCl structure, such as TiN, TiC, CrN, etc. Chemical bonding characters were evaluated based on the MO calculations, which were correlated to the experimental surface free energy. The dispersion and polar components of surface free energy indicated high correlation with the bond overlap population of the surface bonds and the net charge of inside atoms of the cluster models, respectively. Among the ceramic materials investigated, MoN had the lowest surface free energy, being expected to be most suitable as the ceramic coating material with high releasability No potential conflict of interest relevant to this article was reported.

The Ceramic Society of Japan and the Korean Ceramic Society Acta Medica Okayama 2187-0764 1 1 2013 Distribution behavior of inorganic constituents in chemical recycling processes of a municipal waste slag 108 113 EN Kohei Omura Shinichi Sakida Yasuhiko Benino Tokuro Nanba No potential conflict of interest relevant to this article was reported.

岡山大学環境管理センター Acta Medica Okayama 0917-1533 33 2012 湿式ボールミル法を用いた無機性産業廃棄物の再資源化技術の開発 6 12 EN Shinichi Sakida Yasuhiko Benino Tokuro Nanba The possibility of material recycling of inorganic slag by wet ball milling with distilled water and an ethylenediaminetetraacetic acid disodium salt dehydrate (EDTA·2Na·2H2O) reagent was investigated. The wet ball milling of the simulated waste slag powder was performed using a ball mill pot and balls in air for 10 - 100 h at room temperature with the rotational speed fixed at 200 rpm. The fractions of CaO and Fe2O3 in the specimens obtained by wet-ball-milling the simulated waste slag powder decreased, that of SiO2 increased, and those of Al2O3 and Na2O hardly changed. These specimens contained 0.1 – 0.8mass% ZrO2. Appropriate solution and time for wet ball milling were 300 ml distilled water and 20 h, respectively. When the wet ball milling of the simulated waste slag powder was performed twice, the fractions of CaO, Al2O3 and Fe2O3 in the specimen obtained after repeated wet ball milling decreased, those of SiO2 and ZrO2 increased and that of Na2O hardly changed in comparison with those in the specimen wet-ball-milled once. The insoluble end product obtained by soaking the specimen wet-ball-milled once in 6M HCl for 20 hours was composed of 98.5mass% SiO2 and 0.6mass% or less other oxides and is usable as glass material. No potential conflict of interest relevant to this article was reported.

The Ceramic Society of Japan Acta Medica Okayama 1882-0743 117 1371 2009 Chemical recycling of municipal waste slag by using phase separation 1195 1198 EN Tokuro Nanba Yutaro Kuroda Shinichi Sakida Yasuhiko Benino A chemical recycling method by using phase separation was applied to municipal waste slags. Glasses were prepared from incineration ash and ash-melted slag, where B(2)O(3) was added to promote phase separation. The glasses were heat-treated at temperatures higher than their glass transition temperatures, and they were soaked in hydrochloric acid, leaching CaO, Fe(2)O(3), K(2)O, and S. Transparent and colorless solids containing ca. 80 mass% of SiO(2) were successfully obtained as residues. It was suggested that phase separation took place not in the heat-treatment but in the vitrification process, and further characterizations are however required to investigate the phenomena at microscopic levels in the recycling processes. No potential conflict of interest relevant to this article was reported.

The Ceramic Society of Japan Acta Medica Okayama 1882-0743 118 1379 2010 Phase separation of borosilicate glass containing sulfur 603 607 EN Keiji Saiki Shinichi Sakida Yasuhiko Benino Tokuro Nanba A 10Na(2)S·30B(2)O(3)·60SiO(2) (mol %) glass was prepared, and the changes in glass structure and chemical state of sulfur caused by phase separation were investigated. In the as-prepared and heat-treated glasses, sulfur was present as S(2)− anion and polysulfide S(2)− and S(3)− anions, and Si–S and B–S bonds were not confirmed. A phase separation by spinodal decomposition was observed after heat-treatment, where sulfur was preferentially distributed to borate-rich phase. Even after the phase separation, formation of non-bridging oxygen was not recognized. The preferential distribution of sulfur anions in the present glass was explainable on the basis of the change in population of sodium ions, which compensated the negatively-charged sulfur anions. No potential conflict of interest relevant to this article was reported.

岡山大学環境管理センター Acta Medica Okayama 0917-1533 31 2009 湿式ボールミル法を用いた無機性汚泥の再資源化技術の開発 26 31 EN Shinichi Sakida Ryusuke Kuroda Yasuhiko Benino Tokuro Nanba The possibility of material recycling of inorgamic sludge by wet ball milling with distrilled water and an ethylenediaminetetraacetic acid disodium salt dehydrate (EDTA・2Na・2H(2)O)reagent was investigated. The inorganic sludge consisted of 14.1mass% of the heat-treated sludge obtained after drying and heat treatment, 20.1mass% of active carbon, and 65.9mass% of water. The wet ball milling of the heat-treated sludge was performed using a ball pot and balls in air for 40 h at room temperature with the rotational speed fixed at 200rpm. The fractions of Mn, Fe, Ni, Cu, and Zr in the specimens obtained by wet-ball-milling the heat-treated sludge decreased and those of Si and Al increased. Appropriate content of distilled water and weight of the heat-treated sludge for wet ball milling were 150-250 ml and 4.5 g or less, respectively. When the wet ball milling of the heat-treated sludge was perfomed twice,the fractions of Mn, Fe, Ni, Cu, and Zr in the specimen obtained after repeated wet ball milling remarkably decreased and that of Si increased in comparison with those in the specimens wet-ball-milled once. This suggests that the repeat of wet ball milling of the heat-treated sludge leads to a colorless specimen without colored ions such as Mn, Fe, Ni, and Cu. No potential conflict of interest relevant to this article was reported.