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Oxidation of TiN1-x as a New Method for the Preparation of N-Doped TiO2 Photocatalysts
Get PDF国立大学法人長岡技術科学大学博士（工学）doctoral thesi
Rough Set Models and Knowledge Acquisition for Imperfect Information Systems
Get PDF国立大学法人長岡技術科学大学博士（工学）doctoral thesi
分布型流出モデルを用いた洪水到達時間の調査
No full textArticleThe objective of this study is to investigate the relationship between flood concentration time and geograpgical and hydraulical characteristics by using a distributed hydrological model. The distributed model makes it possible to route the runoff generated over the whole catchment without any simplification. This model is applied to Uono river basin of 362km^2. The flood concentration time of Uono river basin itself and its 14 subbasins with different drainage areas are derived by driving the model with constant rainfall, 15mm/hr and 60mm/hr. Furthermore, this procedure is applied to virtual basins generated by digitally enlarging or shrinking above basin and subbasins. The flood concentration time of all these basins are plotted against geographical index and hydraulic index induced based on kinematic wave theory. Finally, a formula to estimate flood concentration time is proposed. It is shown that this formula represent the flood concentration time of Uono river basin and its 14 subbasins very well.journal articl
Internal Control of Secure Information and Communication Practices through Detection of User Behavioural Patterns
Get PDF国立大学法人長岡技術科学大学博士（工学）doctoral thesi
Fabrication of CuBi2O4 photocathode through novel anodic electrodeposition for solar hydrogen production
Get PDFArticleCopper bismuth oxide (CuBi2O4) film electrodes were fabricated by anodic co-electrudepusitiun of Bi2O3 and CuO, followed by heat treatment in air at 500 ℃. The compositions of the electrolyte solution, such as concentrations of Cu2+, Bi3+, and tartaric acid, alkaline strength, and temperature, were optimized to fabricate pure CuBi2O4 films on FTO substrates. XRD and optical absorption were employed to confirm the formation of CuBi2O4, and SEM observation showed the fabrication of a closed packed film with good contact to the FTO substrate. Mott-Schottky plots based on Nyquist plots at various potentials gave the flat band potential of 0.62 V (vs. Ag/AgCl) at pH 6.0. Since the band gap energy measured was 1.80 eV, the conduction band bottom locates at -0.98 V (vs. NHE). At the potential more negative than 0 V (vs. Ag/AgCl), the photo cathodic current fur hydrogen production was observed under visible light irradiation in a deoxygenated 0.1M Na2SO4 solution. The film electrode sustained the photo electrochemical activity in the electrolyte solution at -0.3 V (vs. Ag/AgCl), at least, for 100 min.journal articl
An improved model for waste management from fish farming in tidal river
No full textArticleThis paper describes the improvements of the 3D model proposed by Trieu et al. (2010). The model was applied to simulate the pollutant transport from fish cages (group of cages located closely together that was assigned as the single point source of pollution discharge) in the river system. In contrast, the pollution discharge from both the pond culture and the cage culture was considered in the present study. Moreover, the complete suspension was modeled by calculating the concentration of particle wastes load from riverbed. Furthermore, the conservation of simulation was ensured by using the finite volume method instead of the finite difference method to solve the 2D flow field. The improved model simulated nutrient discharge from the intensive Pangasius farming in the Mekong Delta, Vietnam. The simulated output was verified with the observed data. A good agreement between the observed and simulated data proves that the improved model could help decision makers for better planning and monitoring purposes.journal articl
