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.

American Chemical Society Acta Medica Okayama 2470-1343 7 15 2022 Eco-Benign Orange-Hued Pigment Derived from Aluminum-Enriched Biogenous Iron Oxide Sheaths 12795 12802 EN Katsunori Tamura Graduate School of Natural Science and Technology, Okayama University Yuri Oshima Graduate School of Natural Science and Technology, Okayama University Yuta Fuse Graduate School of Natural Science and Technology, Okayama University Noriyuki Nagaoka Advanced Research Center for Oral and Craniofacial Sciences, Okayama University Tatsuki Kunoh Graduate School of Natural Science and Technology, Okayama University Makoto Nakanishi Graduate School of Natural Science and Technology, Okayama University Tatsuo Fujii Graduate School of Natural Science and Technology, Okayama University Tokuro Nanba Graduate School of Environmental and Life Science, Okayama University Jun Takada Graduate School of Natural Science and Technology, Okayama University Inorganic pigments have been widely used due to their low cost of production, strong hiding power, and chemical resistance; nevertheless, they have limited hue width and chromaticity. To eliminate these disadvantages, we herein propose the use of an ingenious biotemplate technique to produce Al-enriched biogenic iron oxide (BIOX) materials. Spectrophotometric color analysis showed that high levels of Al inclusion on heat-treated BIOX samples produced heightened yellowish hues and lightness. The Al-enriched BIOX sheaths exhibited a stable tubular structure and excellent thermal stability of color tones after heating at high temperatures and repetitive heat treatments. Ultrastructural analysis and mechanical destruction experiments revealed that the highly chromatic orange-hue of these pigments are ascribed probably to an ingenious cylindrical nanocomposite architecture composed of putative Fe-included low crystalline Al oxide regions and hematite particles embedded therein. The present work therefore demonstrates that the bioengineered material can serve as an epochal orange-hued inorganic pigment with low toxicity and marked thermostability that should meet large industrial demand. 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 0914-5400 113 1313 2005 Consideration on the Correlation between Basicity of Oxide Glasses and O1s Chemical Shift in XPS 44 50 EN Tokuro Nanba Yoshinari Miura Shinichi Sakida O1s binding energy measured by X-ray photoelectron spectroscopy (XPS) is candidate as a new tool to determine a new scale of Lewis basicity of oxide ions in glass. Some mathematical expressions for the basicity or XPS chemical shift, such as charge parameter and optical basicity, were compared with the experimental O1s binding energy in binary alkali oxide glasses. The expressions so far in use needed some modification in parameters. A new empirical expression introduced in this paper gives a new concept and universal scale of basicity. No potential conflict of interest relevant to this article was reported.

The Ceramic Society of Japan Acta Medica Okayama 1882-0743 116 1350 2008 Chemical recycling of inorganic wastes by using phase separation of glass 220 223 EN Tokuro Nanba Shuhei Mikami Takuya Imaoka Shinichi Sakida Yoshinari Miura A chemical recycling process using phase separation of glass was applied to a granulated blast furnace slag with high CaO content. Glasses were prepared by adding B(2)O(3) to the slag in order to promote phase separation, and the glasses were heat-treated above glass transition temperature. In the subsequent acid-treatment, however, gelation due to the elution of SiO(2) phase containing CaO occurred, not obtaining high SiO(2) solids. Then, pretreatment was introduced to reduce CaO content in slag, where the raw slag was briefly washed in acid. The slag glasses prepared from the pretreated slag were commonly phase-separated by heat-treatment regardless of B(2)O(3) content. After subsequent acid-treatment, colorless insoluble solids were successfully recovered. The end products consist of 70-90 mass% SiO(2), and coloring ions such as Mn, Fe and Cr were almost completely removed from the slag glasses. Reutilization as raw materials for glass is expected. 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.

Pergamon-Elsevier Science Ltd. Acta Medica Okayama 0016-7037 68 24 2004 A theoretical interpretation of the chemical shift of Si-29 NMR peaks in alkali borosilicate glasses 5103 5111 EN Tokuro Nanba Mitsunori Nishimura Yoshinari Miura In Si-29-NMR, it has so far been accepted that the chemical shifts of Q(n) Species (SiO4 units containing n bridging oxygens) were equivalent between alkali borosilicate, and boron-free alkali silicate classes. In the sodium borosilicate glasses with low sodium content. however. a contradiction was confirmed in the estimation of alkali distributions B-11 NMR suggested that Na ions were entirely distributed to berate groups to form BO4 units, whereas a -90 ppm component Was also observed in Si-29-NMR spectra, which has been attributed to Q(3) species associated with a nonbridging oxygen (NBO). Then. cluster molecular orbital calculations were performed to interpret the -90 ppm component in the borosilicate, glasses. It Was found that a silicon atom which had two tetrahedral borons (B4) as its second nearest neighbors was similar in atomic charge and Si2p energy to the Q(3) species in boron-free alkali silicates. Unequal distribution of electrons in Si-O-B4 bridging bonds was also found. where much electrons Were localized oil the Si-O bonds. It was finally concluded that the Si-O-B4 bridges with narrow bond angle were responsible for the -90 ppm Si-29 component in the borosilicate glasses. There still remained another interpretation: the Q(3) species were actually present in the glasses. and NBOs in the Q(3) species were derived from the tricluster groups. such as (O3Si)O(BO3)(2). In the classes With low sodium content. however. it was concluded that the tricluster groups were not so abundant to contribute to the -90 ppm component. No potential conflict of interest relevant to this article was reported.

岡山大学保健環境センター環境安全部門 Acta Medica Okayama 0917-1533 29 2007 ガラスの分相現象を利用した高炉水砕スラグの再資源化技術の開発 11 15 EN Shinichi Sakida Syuuhei Mikami Tokuro Nanba Toshinari Miura A novel recycling process of blast furnace slag was developed in order to obtain colorless silica−rich solids by using phase separation of borosilicate glass. B(2)O(3) was added to blast furnace slag to promote the phase separation. The slag glasses were heat-treated above glass transition temperatures. The slag glass prepared from blast furnace slag gelled after the heat treatment and the subsequent three types of acid treatment. The ratios of SiO(2) component in the gels were 40 - 60mass%. On the other hand, phase separation was observed on the surface of the slag glasses prepared from pre-treated slag by 2.5N HCI after the heat treatment. After soaking in acid, they did not gel and changed to insoluble colorless solids. According to compositional analyses, it was found that the insoluble colorless solids contained 70 - 90mass% SiO(2). No colored ions such as Cr, Mn, and Fe were confirmed in the remaining insolubles by optical absorption measurement. Therefore, the colorless silica-rich solids were successfully obtained in the present process. The end products obtained in the present process are expected as material of glass. No potential conflict of interest relevant to this article was reported.

岡山大学環境理工学部 Acta Medica Okayama 1341-9099 4 1 1999 Photoconductive and Photovoltaic Properties in Cadmium Bismuth Aluminate Glasses 147 158 EN Danping Chen Tomohiro Watanabe Yoshinari Miura Tokuro Nanba 10.18926/fest/19742 Photo-induced phenomena such as photoconductive and photovoltaic effects were investigated for the glasses in CdO-Bi(2)O(3)-Al(2)O(3) system. Photoconductive effect was characterized by a slow decay of photocurrent (persitent photoconductivity). The decay rate decreased with increasing CdO content and decreasing Bi(2)O(3) content. Photovoltage was very small at room temperature but increased to an obvious value on heating. The photoconductivity and photovoltage were increased with CdO content and enhanced by heat treatment in air. The valence band spectra of X-ray photoelectron spectroscopy showed that the hybridization of Cd 4d and O 2p orbitals increases with decreasing Bi(2)O(3) content and increasing CdO content in the glasses. As the results maximum tends to flat. This type of band structure inhibits the rapid recombination of electrons and holes. The persistent photoconductivity of the glasses may be attributed to deep energy level of DX centers. Deep energy levels of the glasses are able to prevent the recombination because they have a repulsive barrier for both electron emission and capture. No potential conflict of interest relevant to this article was reported.

Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 26 2 1992 Preparation of Mullite Dispersed Silica Ceramics through Sol-Gel Processing 61 67 EN Akiyoshi Osaka Tokuro Nanba Jun Takada Yoshinari Miura 10.18926/15473 Mullite-dispersed silica ceramics were prepared through sol-gel processing by the use of tetraethoxy silane, aluminium nitrate and aluminium isopropoxide as the Si and Al sources where HCl and HN0(3) were the catalyst. Effect of the starting materials, solvents and catalysts was examined on the gelation time or temperature of mullite precipitation. Apparent activation energy of gelation ranged from 80 to 95kJ/mol. The presence of AI in the sols elongated the gelling time suggesting the formation of chelate bonds between AI and Si-OR or Si-OH bonds. No potential conflict of interest relevant to this article was reported.

Faculty of Engineering, Okayama University Acta Medica Okayama 0475-0071 26 2 1992 Preparation and Characterization of Ti(2)O(3) Films Deposited on Sapphire Substrate by Activated Reactive Evaporation Method 69 75 EN Tatsuo Fujii Tokuro Nanba Akiyoshi Osaka Yoshinari Miura Jun Takada 10.18926/15436 (001)-oriented Ti(2)O(3) films were epitaxially grown on a(001)-face of sapphire single-crystalline substrate by an activated reactive evaporation method. The formation ranges of stoichiometric and nonstoichiometric Ti(2)O(3) films were determined as a function of the substrate temperature (Ts), the oxygen pressure (Po(2)) and the deposition rate. Stoichiometric Ti(2)O(3) films were grown at Ts≧673K under Po(2)≧1.0×10(-4)Torr, which showed the metal-insulator transition with a sharp change in electrical resistivity from 3.5×10(-2) to 2.6×10(-3)Ωcm at 361K. Nonstoichiometric films prepared under less oxidized conditions did not exhibit the transition. The nonstoichiometry of the Ti(2)O(3)films was discussed in terms of excess Ti ions. No potential conflict of interest relevant to this article was reported.

岡山大学保健環境センター環境安全部門 Acta Medica Okayama 0917-1533 28 2006 SnOベースガラスの鉛代替光学ガラスへの応用の検討 28 33 EN Shinichi Sakida Koichi Masuda Tokuro Nanba Yoshinari Miura The preparation of SnO-SiO(2), SnO-B(2)O(3), and SnO-GeO(2) glasses by melting in air was performed. The prepared SnO-GeO(2) glasses were large enough to measure optical properties whereas the vitrification in SnO-SiO(2) and SnO-B(2)O(3) systems was difficult. PbO-GeO(2) and BiO(1.5)-GeO(2) glasses were also prepared for comparison with SnO-GeO(2) glasses. The densities, glass transition temperatures, and optical properties such as refractive indices, dispersion, and transmission spectra of SnO-GeO(2), PbO-GeO(2), and BiO(1.5)-GeO(2) glasses were measured. On the basis of the results, the potential for SnO-GeO(2) glasses as lead-free glasses is particularly discussed from the viewpoint of optical properties. 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 29 2007 ガラスの分相現象を利用した高炉水砕スラグの再資源化技術の開発 11 15 EN Shinichi Sakida Syuuhei Mikami Tokuro Nanba Yoshinari Miura A novel recycling process of blast furnace slag was developed in order to obtain colorless silica-rich solids by using phase separation of borosilicate glass. B(2)O(3) was added to blast furnace slag to promote the phase separation. The slag glasses were heat-treated above glass transition temperatures. The slag glass prepared from blast furnace slag gelled after the heat treatment and the subsequent three types of acid treatment. The ratios of SiO(2) component in the gels were 40 – 60mass%. On the other hand, phase separation was observed on the surface of the slag glasses prepared from pre-treated slag by 2.5N HCl after the heat treatment. After soaking in acid, they did not gel and changed to insoluble colorless solids. According to compositional analyses, it was found that the insoluble colorless solids contained 70 - 90mass% SiO(2). No colored ions such as Cr, Mn, and Fe were confirmed in the remaining insolubles by optical absorption measurement. Therefore, the colorless silica-rich solids were successfully obtained in the present process. The end products obtained in the present process are expected as material of glass. 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 30 2008 鉛フリー光学ガラスとしてのSnO-B(2)O(3)ガラスの光学特性 39 44 EN Shinichi Sakida Tokuro Nanba Yoshinari Miura The preparation of SnO-B(2)O(3) and SnO-SiO(2) glasses by melting in Ar atomosphere was performed. The prepared SnO-B(2)O(3) glasses were large enough to measure optical properties whereas the vitrification in SnO-SiO(2) system was very difficult. PbO-B(2)O(3) and BiO1.5-B(2)O(3) glasses were also prepared for comparison with SnO-B(2)O(3) glasses. The densities, glass transition temperatures, and optical properties such as refractive indices, dispersion, and transmission spectra of SnO-B(2)O(3), PbO-B(2)O(3), and BiO(1.5)-B(2)O(3) glasses were measured. On the basis of the obtained results, the potential for SnO-B(2)O(3) glasses as lead-free glasses is particularly discussed from the viewpoint of optical properties. No potential conflict of interest relevant to this article was reported.

岡山大学環境理工学部 Acta Medica Okayama 1341-9099 2 1 1997 活性化反応蒸着法によるZnO系透明導電膜の作製と物性 121 129 EN Takashi Fujiwara Tatsuo Fujii Tokuro Nanba Jun Takada Yoshinari Miura 10.18926/fest/11614 Zinc oxide films were prepared on silica glass substrates by the use of an r.f. activated reactive evaporation (ARE) method, and were examined by X-ray diffraction (XRD) and scanning electron microscope (SEM). The electrical conductivity of the films and the doping effect of Al ions were also investigated. XRD measurements indicate that the films were c-axis oriented and that an r.f. plasma of Zn and O was necessary for the ZnO film deposition. Substrate temperature, oxygen gas pressure, evaporation rate, r.f. power and Al doping amount affect the c-axis orientation, the growth rate, the microstructure of the films and electrical conductivity. Optimum conditions with a fine texture of the surface and having good ctystallinity as well as good conductivity (≒10(-4)Ω・cm) were as follows : the substrate temperature; 200℃, the total evaporation rate; 1.0Å/s, the oxygen pressure; 2.0×10(-4) Torr, the r.f. power; 250W and the Al evaporation rare ratio; 2〜6%. The films with 1.0×10(-3)Ω・cm were prepared at 50℃ for the substrate temperature. No potential conflict of interest relevant to this article was reported.

岡山大学環境理工学部 Acta Medica Okayama 1341-9099 3 1 1998 酸化物ガラスの塩基度とXPSによるO1ｓ束縛エネルギーの化学シフトの相関に関する考察 145 156 EN Tokuro Nanba Yoshinari Miura 10.18926/fest/11578 Binding energy of O1s core electron measured in XPS is a candidate to determine new scale of Lewis basicity of oxide ion in glass. Some mathematical expressions for the basicity or XPS chemical shift, such as charge parameter and optical basicity, are compared with experimental O1s binding energy in binary alkali oxide glasses. The expressions so far in use need some modification in parameters. A new empirical expression introduced in this paper gives new concept and universal scale of basicity. No potential conflict of interest relevant to this article was reported.

岡山大学環境理工学部 Acta Medica Okayama 1341-9099 7 1 2002 Tm(3+)含有結晶化ガラスのアップコンバージョン特性と光散乱 119 125 EN Yoshinari Miura Yong Ding Takashi Murata Yusuke Himei Tokuro Nanba 10.18926/fest/11541 Glass-ceramics containing Pb(x)Cd(1-x)F(2) microcrystallites were prepared through heat treatment of Tm(3+)/Yb(3+)doped SiO(2)-Al(2)O(3)-PbF(2) glasses. The crystallite size was controlled by varying the heat-treatment time. By changing glass composition, two types of strong optical scattering, Rayleigh and Mie scattering modes were observed for the glass ceramics. In the case of Rayleigh scattering, the scattering region expanded to the long-wavelength side with increasing the heat-treatment time. On the other hand, in the case of Mie scattering, the region were hardly dependent on wavelength, and visible light was widely scattered. It was argued that the different scattering phenomena were caused by the different size of the crystallites or their morphogical texture. Furthermore, the glass-ceramics with strong optical scattering showed higher upconversion fluorescence intensity than the matrix glass. The mechanisms for the enhanced upconversion due to the scattering were discussed. No potential conflict of interest relevant to this article was reported.

岡山大学環境理工学部 Acta Medica Okayama 1341-9099 7 1 2002 長残光性透明ガラスセラミックスの作製における超音波前処理効果 113 118 EN Teruhide Inoue Mizuho Nakashima Tokuro Nanba Yoshinari Miura 10.18926/fest/11538 The effects of ultrasonic surface treatment (UST) on the crystallization behavior and optical emission properties were investigated for the transparent glass-ceramics prepared from calcium aluminosilicate glasses co-doped with Eu(2+), Nd(3+). The glass-ceramics A were prepared by sintering a glass 45CaO・45Al(2)O(3)・10SiO(2) (mol%) containing 0.5Eu(2)O(3)+1Nd(2)O(3) under a 2% H(2)+98% Ar reducing atmosphere. In the glass-ceramics A, three crystalline phases, CaAl(2)O(4) (CA), CaAl(4)O(7) (CA2) and Ca(2)Al(2)SiO(7) (CAS) were commonly confirmed by X-ray diffraction. No drastic change in the amount of the precipitated crystalline phases was observed even in the case using UST of CA powders. It was suggested that the optical emission properties of the glass-ceramics A was responsible for the CA2 crystals. The glass-ceramics B were also prepared from a 51CaO・42Al(2)O(3)・7SiO(2) glass. The CA crystals were separately precipitated in the glass-ceramics B. In particular, a large amount of CA was successfully produced by stirring the UST suspension to prevent the sedimentation of the UST particles. The glass-ceramic B so-prepared showed strong photoluminescence but weak phosphorescence compared with other glass-ceramics B, indicating that the photoluminescence and phosphorescence were originated in different electron-trapping levels. The amount of the trap levels associated with the long lasting phosphorescence, such as oxygen vacancies, was probably small in the glass-ceramic B prepared with the stirring UST. No potential conflict of interest relevant to this article was reported.

岡山大学環境理工学部 Acta Medica Okayama 1341-9099 9 1 2004 電位差適定によるセラミック粉体の表面電位の測定 153 162 EN Yoshinari Miura Tokuro Nanba Masakatsu Shinoda 10.18926/fest/11476 Surface states of ceramic particles such as SiO(2), Al(2)O(3), Si(3)N(4) and so on suspended in aqueous alkaline solutions were successfully and easily determined by a potentiometric titration method. Isoelctric point, iep and excess surface charge density were classified and evaluated for many ceramic particles from the view points of aggregation and dispersion of particles and solubility in aqueous solution. No potential conflict of interest relevant to this article was reported.

岡山大学環境理工学部 Acta Medica Okayama 1341-9099 12 1 2007 ガラスの相分離を利用した都市ゴミ溶融スラグのマテリアルリサイクル 161 165 EN Takuya Imaoka Shinichi Sakida Tokuro Nanba Yoshinari Miura 10.18926/fest/11475 A novel recycling process of municipal waste slags obtaining Fe-free colorless materials was developed by using a phase separation of borosilicate glass. B(2)O(3) was added to a simulated waste slag to promote the phase separation. The slag glasses were heat-treated above glass transition temperatures, from which phase separation was successfully induced. The phase-separated slag glasses were still colored in black due to Fe ions, and after soaking in acid, they were successfully bleached, obtaining colorless solids. According to compositional analyses, no Fe ions were confirmed in the remaining insolubles, indicating that Fe ions were preferentially incorporated into the borate-rich phases soluble in acid. The main constituent of the colorless solids was SiO(2) and the end products obtained in the present process were expected as an alternative of pure silica glass. No potential conflict of interest relevant to this article was reported.