JaLCDOI 10.18926/fest/11476
Title Alternative Evaluation of Surface State of Ceramic Particles Suspended in Aqueous Solution by Potentiometric Titration Method
FullText URL 009_153_162.pdf
Author Miura, Yoshinari| Nanba, Tokuro| Shinoda, Masakatsu|
Abstract 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.
Keywords potentiometric titration method isoelctric point excess surface charge density ceramic particle suspension aqueous solution
Publication Title 岡山大学環境理工学部研究報告
Published Date 2004-02-27
Volume volume9
Issue issue1
Start Page 153
End Page 162
ISSN 1341-9099
language 日本語
File Version publisher
NAID 120002313753
JaLCDOI 10.18926/fest/11475
Title Alternative Material Recycling of Municipal Waste Slags by Using Phase Separation of Glass
FullText URL 012_161_165.pdf
Author Imaoka, Takuya| Sakida, Shinichi| Nanba, Tokuro| Miura, Yoshinari|
Abstract 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.
Keywords slag recycling colorless glass phase separation
Publication Title 岡山大学環境理工学部研究報告
Published Date 2007-03-15
Volume volume12
Issue issue1
Start Page 161
End Page 165
ISSN 1341-9099
language 日本語
File Version publisher
NAID 120002313957
JaLCDOI 10.18926/fest/11541
Title Alternative Upconversion property and light scattering in Tm(3+)-doped glass-ceramics
FullText URL 007_119_125.pdf
Author Miura, Yoshinari| Ding, Yong| Murata, Takashi| Himei, Yusuke| Nanba, Tokuro|
Abstract 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.
Keywords Optical scattering Glass-ceramics Oxyfluoride glass Microcrystallite Upconversion fluorescence
Publication Title 岡山大学環境理工学部研究報告
Published Date 2002-03-22
Volume volume7
Issue issue1
Start Page 119
End Page 125
ISSN 1341-9099
language 日本語
File Version publisher
NAID 120002313480
JaLCDOI 10.18926/fest/11538
Title Alternative Effects of ultrasonic treatment on the preparation of transparent glass-ceramic phosphor
FullText URL 007_113_118.pdf
Author Inoue, Teruhide| Nakashima, Mizuho| Nanba, Tokuro| Miura, Yoshinari|
Abstract 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.
Keywords ultrasonic surface treatment (UST) surface crystallization glass-ceramics long lasting phosphorescence calcium aluminosilicate glass
Publication Title 岡山大学環境理工学部研究報告
Published Date 2002-03-22
Volume volume7
Issue issue1
Start Page 113
End Page 118
ISSN 1341-9099
language 日本語
File Version publisher
NAID 120002313433
JaLCDOI 10.18926/fest/19742
FullText URL 004_147_158.pdf
Author Chen, Danping| Watanabe, Tomohiro| Miura, Yoshinari| Nanba, Tokuro|
Abstract 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.
Keywords Photoconductivity Photovoltage Persistent photoconductivity CdO-Bi(2)O(3)-Al(2)O(3) glasses Electronic state
Publication Title 岡山大学環境理工学部研究報告
Published Date 1999-02-26
Volume volume4
Issue issue1
Start Page 147
End Page 158
ISSN 1341-9099
language 英語
File Version publisher
NAID 120002309190
JaLCDOI 10.18926/fest/11578
Title Alternative Consideration for the correlation between basicity of oxide glasses and chemical shift of O1s binding energy in XPS
FullText URL 003_145_156.pdf
Author Nanba, Tokuro| Miura, Yoshinari|
Abstract 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.
Publication Title 岡山大学環境理工学部研究報告
Published Date 1998-01-14
Volume volume3
Issue issue1
Start Page 145
End Page 156
ISSN 1341-9099
language 日本語
File Version publisher
NAID 120002313359
JaLCDOI 10.18926/fest/11614
Title Alternative Preparation and Properties of ZnO Transparent Conductive Thin Films by Activated Reactive Evaporation Method
FullText URL 002_121_129.pdf
Author Fujiwara, Takashi| Fujii, Tatsuo| Nanba, Tokuro| Takada, Jun| Miura, Yoshinari|
Abstract 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.
Keywords ZnO film Al doped ZnO transparent conductive film r.f. activated reactive evaporation method
Publication Title 岡山大学環境理工学部研究報告
Published Date 1997-01-10
Volume volume2
Issue issue1
Start Page 121
End Page 129
ISSN 1341-9099
language 日本語
File Version publisher
NAID 120002313550
Author Fujii, Tatsuo| Sakata Naoki| Nanba, Tokuro| Osaka, Akiyoshi| Miura, Yoshinari| Takada, Jun|
Published Date 1992-03-28
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Volume volume26
Issue issue2
Content Type Departmental Bulletin Paper
JaLCDOI 10.18926/fest/52229
Title Alternative Material design for the ceramics coating with high mold releasability by using molecular orbital calculations
FullText URL fest_019_022_025.pdf
Author Nanba, Tokuro| Fujihara, Jiro| Sakida, Shinichi| Benino, Yasuhiko|
Abstract  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
Keywords Material design Ceramic coating Releasability Molecular orbital calculation
Publication Title 岡山大学環境理工学部研究報告
Published Date 2014-03
Volume volume19
Issue issue1
Start Page 22
End Page 25
ISSN 2187-6940
language 日本語
File Version publisher
NAID 120005394644
Author Omura, Kohei| Sakida, Shinichi| Benino, Yasuhiko| Nanba, Tokuro|
Published Date 2013-03
Publication Title Journal of Asian Ceramic Societies
Volume volume1
Issue issue1
Content Type Journal Article
Author Sakida, Shinichi| Benino, Yasuhiko| Nanba, Tokuro|
Published Date 2012-02
Publication Title 環境制御
Volume volume33
Content Type Departmental Bulletin Paper
Author Nanba, Tokuro| Miura, Yoshinari| Sakida, Shinichi|
Published Date 2005-01
Publication Title Journal of the Ceramic Society of Japan
Volume volume113
Issue issue1313
Content Type Journal Article
Author Nanba, Tokuro| Mikami, Shuhei| Imaoka, Takuya| Sakida, Shinichi| Miura, Yoshinari|
Published Date 2008-02
Publication Title Journal of the Ceramic Society of Japan
Volume volume116
Issue issue1350
Content Type Journal Article
Author Nanba, Tokuro| Kuroda, Yutaro| Sakida, Shinichi| Benino, Yasuhiko|
Published Date 2009-11
Publication Title Journal of the Ceramic Society of Japan
Volume volume117
Issue issue1371
Content Type Journal Article
Author Saiki, Keiji| Sakida, Shinichi| Benino, Yasuhiko| Nanba, Tokuro|
Published Date 2010-07
Publication Title Journal of the Ceramic Society of Japan
Volume volume118
Issue issue1379
Content Type Journal Article
Author Sakida, Shinichi| Kuroda, Ryusuke| Benino, Yasuhiko| Nanba, Tokuro|
Published Date 2009-12
Publication Title 環境制御
Volume volume31
Content Type Departmental Bulletin Paper
Author Nanba, Tokuro| Nishimura, Mitsunori| Miura, Yoshinari|
Published Date 2004-12-15
Publication Title Geochimica et Cosmochimica Acta
Volume volume68
Issue issue24
Content Type Journal Article
Author Sakida, Shinichi| Mikami, Syuuhei| Nanba, Tokuro| Miura, Toshinari|
Published Date 2007-10
Publication Title 環境制御
Volume volume29
Content Type Departmental Bulletin Paper
Author Osaka, Akiyoshi| Kawabata Kouji| Nanba, Tokuro| Takada, Jun| Miura, Yoshinari|
Published Date 1992-03-28
Publication Title Memoirs of the Faculty of Engineering, Okayama University
Volume volume26
Issue issue2
Content Type Departmental Bulletin Paper
Author Sakida, Shinichi| Masuda, Koichi| Nanba, Tokuro| Miura, Yoshinari|
Published Date 2006-12
Publication Title 環境制御
Volume volume28
Content Type Departmental Bulletin Paper