Limiting distribution of the score statistic under moderate deviation from a unit root in MA(1)

This article derives an asymptotic distribution of Tanaka's score statistic under moderate deviation from a unit root in a moving average model of order one [MA(1)]. The limiting distribution is classified into three types depending on the order of deviation. In the fastest case, the convergence order of the asymptotic distribution continuously changes from the invertible process to the unit root one. In the slowest case, the limiting distribution coincides with one in the invertible process in the distribution sense. This implies that they share a common asymptotic property. The limiting distribution in the intermediate case has the boundary property between the fastest case and the slowest one.     

Transformations of the wavelength of the light incident upon CdS/CdTe solar cells

A method for the improvement of the spectral response of the CdS/CdTe solar cell was proposed. The coatings of fluorescent coloring agent (FCA) on the cell made the cell sensitive to light at wavelengths below 510 nm, transforming the wavelength of the incident light from non-incentive region (below 510 nm) to incentive region (above 510 nm). The FCA coatings showed about 8% and 14% increases in the maximum power of the solar cell under the radiations of a white and day-light fluorescent lamp, respectively. Possible maximum output powers were predicted by using a simple model for the external quantum efficiency of the cell.     

Heat transfer on tube bundles embedded horizontally in a liquid‐fluidized bed: 2nd report: On tube bundles of fundamental layouts including in‐line layouts

Heat transfer coefficients were measured on tube bundles of fundamental layouts including in‐line layouts embedded horizontally in a liquid‐fluidized bed. Tested tube layouts were single tubes, transverse single tube rows, longitudinal single tube rows, and in‐line arranged tube bundles. A total of 7 kinds of particles were used. Comparisons of the experimental data showed a good agreement with the heat transfer correlation developed for staggered layouts, when the average liquid velocity through each tube bundle was used as the reference velocity for the particle Reynolds number. Distribution of the local heat transfer coefficient was also investigated around tubes. © 2009 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20245     

Increasing chemisorbed silane coupling agents in surface-treated layer of silica particles

In the surface treated inorganic particles with silane coupling agent (SCA), chemisorbed and physisorbed molecules are present in the treated layer. Increasing the amount of chemisorption by increasing the molecular weight of SCAs was investigated. Oligomers formed via self-condensation during storage more than 10 days at room temperature for 3-methacryloxypropyltrimethoxysilane-treated silica particles. Monomeric SCA evaporates easily by heating. The oligomers restrict evaporation, and heating increases the chemisorption. The influence of molecular weight of SCA was investigated. In the case of amino group, the amount of chemisorbed was greater for aminoethylaminooctyltrimethoxysilane with high molecular weight than for 3-aminopropyltriethoxysilane. For SCAs with hydrocarbon chains, the amount of chemisorption was lower for both low molecular weight molecules and decyltrimethoxysilane (D) with a high molecular weight. For fluorocarbon chains, the amount of chemisorption was lower for low molecular weight molecules, whereas it increased significantly by heating for high molecular weight type of 1H,1H,2H,2H-heptadecafluorodecyltriethoxysilane (F). Wide-angle X-ray diffraction analysis of F-treated silica particles showed that the fluorocarbon chains formed an ordered structure. There was no such indication for the D-treated system. This ordered structure seems to influence on higher chemisorption for F-treated systems.     

Modification of a hydrophobic-ligand-containing porous sheet using tri-n-octylphosphine oxide,and its adsorption/elution of bismuth ions

A neutral extractant, tri-n-octylphosphine oxide (TOPO), was used to chemically modify a porous sheet, with a final density of 1.0 mmol/g. First, glycidyl methacrylate (GMA) was graft-polymerized onto a porous polyethylene sheet with an average pore diameter, porosity, and thickness of 1.2 μm, 75%, and 2.0 mm, respectively. Second, an octadecane thiol group was introduced into the poly-GMA graft chain. Third, TOPO was deposited on the graft chain via a hydrophobic interaction. Bismuth chloride solution (BiCl₃ in 0.15 M HNO₃) was forced through the pores of the TOPO-modified porous sheet. The equilibrium binding capacity for bismuth was 0.19 mmol/g. Bismuth ions bound to TOPO were quantitatively eluted with 11 M HNO₃.     

Drying processes for preparation of titania aerogel using supercritical carbon dioxide

Supercritical carbon dioxide drying was performed for the preparation of titania aerogels from sol–gel routes. The conditions of supercritical carbon dioxide drying were 313–323 K and 7.8–15.5 MPa. The solvents in titania wet gels obtained from the sol–gel routes were replaced by acetone. The titania aerogels obtained from supercritical carbon dioxide drying form needle-like structures. In supercritical carbon dioxide drying, the extraction rates of acetone from the wet gels were measured by using an on-line Fourier transform infrared spectroscope. It was found that the titania aerogels with lower cohesion were induced from the formations of homogenous phase for carbon dioxide + acetone system and the lower extraction rates of acetone. Furthermore, titania films were prepared by the depositions of the titania aerogels on ITO-coated PET substrates. The needle-like aerogels with lower cohesion derive the titania film with high surface area.     

Data envelopment analysis for evaluating Japanese universities

In order to evaluate universities from various aspects, we propose a method of utilizing data envelopment analysis (DEA). The management of universities is complex, and it is necessary to find out their strengths and weaknesses so that they may become a better educational institute. In this sense, DEA contributes to the evaluation since it can show the efficiency of universities based on multiple viewpoints. However, when the number of universities evaluated is increased, the results of an evaluation are similar. Therefore, it is difficult to understand the specific points of each university. We propose a method for developing evaluations by adapting the decision-making unit (DMU) to certain viewpoints. The utility and effectiveness of the proposed method are shown by numerical experiments.     

Correlation-based similarity metrics in MBR for ordered data

To improve the precision of memory-based reasoning (MBR) for ordinal data, this article presents correlation-based similarity metrics. The basic idea of this research is an intuitive assumption: if the correlation between the answer and one feature in a sample data set is large, the weight of this feature for predication should be large. To validate this proposal, we promote “leave-one-out cross-validation” for 53 examples which were collected from Japanese client companies who outsource software development to vendor companies. Three measures, including mean absolute error, variance of error, and precision, are compared among the proposed methods: the per-category feature importance (PCF), the per-feature category importance (PFC), the averaged category feature importance (ACF), and the cross-category feature importance (CCF). The Wilcoxon matched-pairs signed ranks test is also discussed.     

Influences of the alkoxy group number and treatment condition on the structure of glycidoxy functional silane-treated layer on silica particles analyzed by 1H pulse NMR

The surface treatment of spherical silica particles using a silane coupling agent with a glycidoxy group was conducted and the effect of the alkoxy group number on the molecular mobility of the silane chain was investigated by ¹H pulse nuclear magnetic resonance (NMR). Silanes with di-alkoxy and tri-alkoxy structures were used, and the silica particles were treated with 2-propanol solution and heated at 120?°C for 24?h after solvent evaporation. The surface coverage of the silica surface was in the range from two to three layers. For multilayer coverage, linear chain and network structures were expected to form on the surface by polycondensation reaction using the di- and tri-alkoxy structures, respectively. However, the relaxation times for silane chains with both di- and tri-alkoxy structures measured by pulse NMR were short, which indicates that both silane chains formed rigid network structures. Fourier transform infrared spectroscopic analysis revealed that ring opening of the epoxy group occurred, followed by reaction to form the network structure, even with the di-alkoxy structure. Ring opening of the epoxy group could be reduced by setting the heating temperature at 80?°C. There was a significant difference in flexibility between the silane-layers with di- and tri-alkoxy structures after heating at 80?°C, as reflected by the relaxation time.     

Startup,performance, and microbial communities of an anammox reactor inoculated with indigenous sludge for the treatment of high-salinity and mesophilic underground brine

Clean Technologies and Environmental Policy - Anaerobic ammonium oxidation (anammox) has been implemented as a cost-effective nitrogen removal process in wastewater treatment. To apply the process...