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In recent years, foundation improvement methods using cementitious material for liquefaction countermeasure in seafront as deep or superficial cement mixing method come into practical use. And, in connection with prolonged stability of improved soils using cementitious materials, leaching from improved soils is discussed. Now, however, there is not enough fundamental data for analysis of leaching properties, such as phase composition of improved soils and so on. Improved soils are often mixed with seawater, but in such cases, there is also not enough fundamental discussion about hydration of cement. This paper is fundamental study for analysis of long-term determination of cement-based improved soils and discusses the hydration and material microstructure of hardened cement mixed with seawater and leaching properties in seawater.

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The role of Al2O3 formed on the surface of AlN particles were investigated at around 1800K by in situ high resolution transmission electron microscopy (HREM) to understand the effects of Al2O3 contaminated layer on the sintering process of AlN. Formation of nano-size particles of Al2O3 was found on the surface of AlN particles, and these nano-particles may have the possibilities of enhancing the sintering of AlN particles and also the formation of defects during sintering.

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The crystal structure of copper iodide (CuI) has been studied at 300 K and 760 K using synchrotron X-ray powder diffraction data. An accurate electron density distribution of CuI has been obtained analyzing the data with a combination of the Rietveld method, a maximum-entropy method (MEM) and MEM-based pattern fitting. The MEM electron-density map of the zinc-blende type -CuI at 300 K indicated that the copper ions are located at the regular 4c position. It was found that the fluorite-type -CuI at 760 K has a large spatial distribution of copper ions along the <111> directions around the regular 8c position and diffusion pathway of mobile copper ions along the <100> direction. These features are responsible for the high ionic conductivity of -CuI. The electron-density maps of CuI at 300 K and 760 K also show covalent bonding between the copper and iodine atoms.

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An X-ray reflectivity (XRR) analysis is a powerful tool to measure true density calculated from the electron density of a thin film sample. Surface roughness and thickness of the sample are also measured simultaneously by this technique. The XRR analysis is available to estimate in detail of a surface reaction model in the growth model of the thin film by a chemical-vapor-deposition (CVD) method. In this study, we measured the density of the thin films of anatase and amorphous silica, synthesized by CVD technique operated under atmosphere. Two growth models were proposed for each film using the results of XRR.

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Combining the electron channeling effects with EELS, we could deduce site-specific electronic structures and chemical bonding. We applied this channeling EELS to Al-containing spinel and garnet crystals. The K edge spectra of octahedrally coordinated Al (Aloct) had a peak 4.5 eV higher than those of tetrahedrally coordinated Al (Altet), in both cases. However, the spinel showed broader Aloct peak width than the garnet, which was interpreted using band calculations by stronger interactions between Aloct in the spinel. These results should give essential information for designing a new optics material, by controlling the site-specific valency or spin states of solute atoms.

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Powder diffraction peak profile with both sharpened peak-top and long tail is often observed, when the collection of small crystallites has broad size distribution. Recent theoretical studies on such diffraction peak profiles have revealed that the sharpened peak profile is naturally expected to be observed for broad size distribution of crystallite size. Analytical method to evaluate the distribution of size as well as the average size have been proposed, which can be easily applied by using a curve fitting procedure. In this study, the author proposes new definitions of sharpness parameters and compares with the known parameters. Validity of a convenient method applying approximate peak profile models will be discussed.

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Heteropolyacids (HPA) are one of the typical acid catalysts for chemical engineering. It is also photocatalyst with strong oxidation power than TiO₂ photocatalyst. In the present work, 12-tungstophospholic acid - TiO₂ nano particle multilayer composite was prepared by layer-by-layer method. Transparent thin film was obtained on quartz grass. UV absorbance and layer thickness increase with the number of deposition cycle indicating that single layer deposition is attained.

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Uniform nitrogen-doped titania mesoporous microspheres were synthesized by a simple one-step solvothermal treatment. Urea was added as pH adjusting agent and the source of nitrogen for doping. The dual-role of urea helps the formation of meso porous structure and the doping of nitrogen into titania to be completed simultaneously during the solvothermal process. Mesoporous microspheres were formed through the random aggregation of nanometer-sized particles. The nitrogen doped titania mesoporous spheres shows higher visible light photocatalytic activity than the undoped titania or commercial Degussa P25. The amount of urea shows the crucial effect on the mesopore size and nitrogen doping amount in titania.

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We have already reported the photocatalytic decomposition of octadecyltrichlorosilane (OTS) as a self-assembled monolayer (SAM) on a silicon wafer under ambient condition at room temperature by use of the porous TiO2 micro wire which was prepared by phase separation-selective leaching process. The application of such SAM is widely studied to a fabrication of a chemical sensor where organic and/or bio molecules arrange on an appropriate substrate nowadays. In this study, the OTS on a silicon wafer was photocatalytically decomposed and machined under various conditions by use of the porous TiO2 micro wire. The effects of UV irradiation time and angle, humidity and oxygen concentration on the decomposition process of OTS were examined.

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The combination of microwave and hydrothermal techniques has been used in the last few years for the synthesis of nanocrystalline powders. In the present research, nitrogen-doped titania (TiO_2-xN_y) nanoparticles with excellent visible-light-reactive photocatalytic activity were successfully prepared by the microwave-hydrothermal process. The effects of different parameters such as reaction time, temperature, and pH value of solvents on the formation of TiO_2-xN_y nanoparticles under microwave-hydrothermal conditions were investigated in details. The obtained TiO_2-xN_y powders showed higher specific surface area, finer particle size, and excellent photocatalytic ability for the oxidative destruction of nitrogen monoxide under irradiation of both visible-light (wavelength>510nm) and UV light (wavelength>290nm).

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Titania/smectite composites were synthesized by mixing of titania sol solution with smectite suspension. The obtained composites were characterized by XRD, XRF, TEM, XPS, and N2-BET. Photocatalytic property of the obtained samples was examined under UV radiation using various organic solutions or under various organic vapors. The obtained composite decomposed 1,4-dioxane in aqueous solution and the decomposition rate was as same as pure TiO2 powder under 400 nm UV.

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We have developed the new type academic-communication-network system "The UCEE Doctoral Researcher Database" in the Support Program for Distinctive University Education by Ministry of Education, Culture, Sports, Science and Technology. This system integrated the automatic literature-survey function, the function which provide the information about job offers, and the communication system between the researcher site based on the SNS(Social Networking Sites) functions like discussion board and personal community. There are four types of users, i.e. doctor researcher, teacher, corporate user, and non-member.

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