Photocatalytic decomposition of gaseous HCHO over a titanium dioxide film formed on a hydrophobic PET sheet

BACKGROUND: The authors (Chem Eng J 148, 234 (2009)) previously demonstrated the excellent performance of a photocatalytic reactor with a parallel array of nine light sources. To enhance the possibility of practical application of this reactor, the present work explores the use of a PET (polyethylene terephthalate) sheet as a new cheap material to support TiO₂, as an alternative to glass tubes. A method of coating the hydrophobic PET sheet with a TiO₂ film using an aqueous coating solution is investigated and the performance of the TiO₂‐PET sheet prepared evaluated. RESULTS: The affinity of the coating solution for the PET sheet is greatly enhanced by addition of 0.01% (w/w) nonionic surfactant (polyoxyethylene lauryl ether). A relatively uniform thin TiO₂ film is formed on the entire surface of the PET sheet by applying the coating solution to the PET sheet and drying it at 100 °C. Decomposition experiments of gaseous HCHO indicate that the photocatalytic activity, although initially low, is increased with repeated use. This is because surfactant molecules added interfere initially with the decomposition of HCHO. After their decomposition, the TiO₂–PET sheet decomposes HCHO at almost the same rate as does the TiO₂–glass tube. CONCLUSION: The photocatalytic reactor with a parallel array of nine light sources can utilize a PET sheet as TiO₂ support with a reduction in material cost. Copyright © 2011 Society of Chemical Industry     

β-FeOOH thin film as positive electrode for lithium-ion cells

β-FeOOH thin film was prepared on the surface of a foamed Ni substrate by liquid phase deposition (LPD) method with a chemical equilibrium reaction between metal-fluoro complex and oxyhydroxide to make a low-cost and environmentally friendly positive electrode for high-power batteries. The new film electrode, with a thickness of 316 nm, was found out to give a large discharge capacity of 260 mAh g⁻¹ at 0.05 C rate even without an electro-conductive material. Furthermore, the electrode also showed good discharge performance with the retention of 69.9% at 10-0.05 C current rate, which means a promising positive active material for high-power use.     

Modeling Party Support of Japanese Voters in the Early 1996

This article investigates factors that influenced Japanese voters in the early 1996 in determining which political party to support. Proportional-odds model, a model which retains ordinal nature of political hues or ideologies of the Japanese political parties, is fitted to the data. Samples with answers “I do not know” to the questions are treated as missing. The EM algorithm enables us to incorporate the samples with missing-values. We found that determining which party to support is a purely political decision for Japanese voters based solely on their ideologies and attitude towards the current cabinet, not to be influenced by their geographical profiles nor financial situations. Missing-value problem were found not to be ignored in the sense that marginally significant or insignificant explanatory variables can easily turn otherwise when the same model is fitted only for the data with no missing-values.

     

Model-based surgical planning and simulation of cranial base surgery

Plastic skull models of seven individual patients were fabricated by stereolithography from three-dimensional data based on computed tomography bone images. Skull models were utilized for neurosurgical planning and simulation in the seven patients with cranial base lesions that were difficult to remove. Surgical approaches and areas of craniotomy were evaluated using the fabricated skull models. In preoperative simulations, hand-made models of the tumors, major vessels and nerves were placed in the skull models. Step-by-step simulation of surgical procedures was performed using actual surgical tools. The advantages of using skull models to plan and simulate cranial base surgery include a better understanding of anatomic relationships, preoperative evaluation of the proposed procedure, increased understanding by the patient and family, and improved educational experiences for residents and other medical staff. The disadvantages of using skull models include the time and cost of making the models. The skull models provide a more realistic tool that is easier to handle than computer-graphic images. Surgical simulation using models facilitates difficult cranial base surgery and may help reduce surgical complications.     

Finite-time settling adaptive observer for linear discrete-time systems

This paper deals with a design method for an adaptive scheme which would identify the parameters and observe the state of any unknown single-input single-output linear discrete-time systems using only input-output data. Kreisselmeier's parametrized system [5] is used instead of the original system. Then the parameter identification process and the state observation process are well separated. To accelerate the convergence rate of the estimates, a finite-time settling scheme is proposed. It is shown that the estimates obtained converges to true values at k = 3n ?1, where k is the discrete time and n is the order of system. A numerical example is given to indicate acceptable performance of the proposed scheme.     

Velocity, electromechanical coupling factor and acoustic loss of surface shear waves propagating along x-axis on rotated Y-cut plates of LiNbO3

Velocity and propagation loss of surface shear waves are measured on free-space and metallised surfaces of LiNbO3 crystals along the x-axis of rotated Y-cut plates as a function of rotation about the x-axis between 35° and 70°. The coupling factor obtained from the velocities is 0.20 for a 35° rotated Y-cut plate and 0.09 for a 70° plate. The coupling factor changes linearly with the rotation angle. The propagation losses over the whole range measured here are less than 5 dB/cm on both free-space and on metallised surfaces. These losses are fairly low and very favourable for fabricating s.a.w. filters.     

Surface acoustic wave based sensors employing ionic liquid for hydrogen sulfide gas detection

This paper describes a new type hydrogen sulfide (H₂S) gas sensor using ionic liquid (IL). In this sensor, a reservoir for the IL was integrated on a surface acoustic wave (SAW) resonator. The IL serves as an absorber for H₂S gas. Mass change due to this absorption is detected as shift in the resonant frequency. In this study, we fabricated and demonstrated the sensor using the lithium niobate (LiNbO₃) SAW resonator with the resonant frequency of 38 MHz. The integrated reservoir was filled by the IL 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim]-[PF₆]). As an experimental result, we observed the linear correlation between the frequency-shift and the exposure time of the sensor to the H₂S gas.     

Anodic acyloxylation based on the acid–base reactions between acetic acid or trifluoroacetic acid and solid-supported bases

We have developed a novel electrolytic system for anodic acyloxylation based on the acid–base reactions between acetic acid or trifluoroacetic acid and solid-supported bases. On the basis of the electrolytic system, anodic acyloxylation of organic compounds, which even have considerably high oxidation potentials, was successfully carried out to provide the corresponding acyloxylated products in moderate to excellent yields. Furthermore, it was found that silica gel supported bases are not only chemically stable under acidic conditions but also electrochemically stable and thus reusable for many times.     

Anisotropy of the spatial distribution of In(Ga)As quantum dots in In(Ga)As-GaAs multilayer heterostructures studied by X-ray and synchrotron diffraction and transmission electron microscopy

High-resolution X-ray and synchrotron (crystal truncation rods) diffraction methods and transmission electron microscopy have been employed to study MBE-grown multilayer In(Ga)As-GaAs heterostructures with arrays of vertically coupled In(Ga)As quantum dots (QDs) in a GaAs matrix. Additional (vertical and lateral) spatial ordering of QDs in perfect crystalline structures, giving rise to undulations of the crystalline planes and quasi-periodic elastic strain, was shown to be essentially anisotropic with respect to crystallographic directions of the [110] type. The anisotropy of the QD formational system of can be accounted for by assuming that the spatial ordering of the QDs and the corrugation of the crystal planes are the initial stages of relaxation of the elastic strain introduced into the system by the QDs. The anisotropic relief of the crystal planes (corrugated growth surface) results from the formation of a system of spatially ordered quantum quasi-wires uniformly filled with QDs. In a multilayer heterostructure with high crystal perfection, the anisotropic relief of the crystal planes is inherited by overlying layers and its amplitude decreases gradually with increasing distance from the source of elastic strain—the superstructure containing In(Ga)As QDs in the given case.