Growth of submicrometer-scale rectangular parallelepiped rutile TiO2 films in aqueous TiCl3 solutions under hydrothermal conditions

Evolution of a new morphology of rutile TiO2 films consisting of nearly single-crystalline parallelepipeds was achieved through hydrothermal treatments of aqueous TiCl3 solutions in the presence of NaCl.     

Fuzzy measure of fuzzy events defined by fuzzy integrals

We define the concept of fuzzy measure of a fuzzy event by using a general form of fuzzy integral proposed by Murofushi, called fuzzy t-conorm integral, encompassing previous definitions. Zadeh defined the probability measure of a fuzzy event, and later the possibility measure of fuzzy event. Using a duality property of fuzzy t-conorm integral, we propose a general definition of fuzzy measure of fuzzy events, which is compatible with previous definitions of Zadeh, and possesses all properties of a fuzzy measure, in particular the duality property. Using our definition, we examine the case of decomposable measures and belief functions. A comparison with previous works is provided.     

Activation of electrode surfaces: semiquantitative characterization of electrode surfaces modified with heteropolyanions

Several Techniques have been used successively or in combination to approach a better understanding of surfaces modified by silicotungstic heteropolyanion. Due to the strikingly high activity of these electrodes for the hydrogen evolution reaction, in particular, there exists a need to identify the chemical composition of the catalyst, to evaluate the amount of catalyst on the surface, and to study the electrochemical behaviour of the “catalyst” itself. Plasma emission spectrometry shows semi-quantitatively that the catalyst resembles the starting material closely, although it is not possible at present to give the exact chemical formula. Electron microprobe analysis (EMA) confirms the presence of tungsten, and especially silicon, on the surface, even though the concentration of this last element is very low. The absence of platinum in the starting HPA, as well as on the electrode surface, is also clearly demonstrated by EMA, which is of prime importance in showing that the “HPA catalyst” is active by itself. Combined coulometry and UV-visible spectroscopy have been used to evaluate the amount of HPA consumed during electrolysis. Cyclic voltammetry shows a surface redox couple corresponding to the catalyst, and well separated from the first redox couple of SiW₁₂O^4-₄ in 0.5 M H₂SO₄ solution. A better understanding of the activation-deactivation processes of the catalytic electrode surface ensues.     

Solid polymer electrolytes based on squaric acid structure

Poly(squarate)s (PPS-1 and PPS-2) were synthesized by the reaction of squaryl dichloride with hydroquinone for PPS-1 and with 2,5-diethoxy-1,4-bis(trimethylsilyloxy)benzene for PPS-2, and the ionic conductivities, thermal properties, and electrochemical and thermal properties of their polymer electrolytes with LiN(CF₃SO₂)₂ were investigated. The ionic conductivity increased with increasing the lithium salt concentration for the PPS-1–LiN(CF₃SO₂)₂ electrolyte, and the highest ionic conductivities of 8.60 × 10⁻⁵ S/cm at 100 °C and 9.57 × 10⁻⁸ S/cm at 30 °C were found at the [Li] to [O] ratio of 2:1. And also, the ionic conductivity for the PPS-1–LiN(CF₃SO₂)₂ electrolyte increased with an increase in the lithium salt concentration, reached a maximum value at the [Li] to [O] ratio of 1:2, and then decreased. The highest ionic conductivity was to be 1.04 × 10⁻⁵ S/cm at 100 °C and 1.71 × 10⁻⁸ S/cm at 30 °C, respectively. Both polymer electrolytes exhibited relatively better electrochemical and thermal stabilities. Addition of the PPS-1 as a plasticizer into the poly(ethylene oxide) (PEO)–LiN(CF₃SO₂)₂ electrolyte system suppressed the crystallization of PEO, and improved the ionic conductivity at room temperature. Invited paper dedicated to Professor W. Weppner on his 65th birthday.     

Nickel-NHC-catalyzed alpha-arylation of acyclic ketones and amination of haloarenes and unexpected preferential N-arylation of 4-aminopropiophenone

Arylation of both acyclic ketones and primary and secondary amines was achieved using a new, simple, stable, and easy-to-access nickel(II)-halide complex bearing mixed PPh3/N-heterocyclic carbene ligands as a catalyst precursor. Acyclic ketones were first arylated at the alpha-position with the nickel catalyst. On the other hand, less basic amines, such as diphenylamine and 4-aminobenzophenone, were more favorable in the catalytic amination of haloarenes than basic amines, contrary to previous reports. N-Arylation of 4-aminopropiophenone was found to proceed selectively without causing alpha-arylation of the ketone group.     

Diffusion-weighted echo-planar imaging of the head and neck using 3-T MRI: Investigation into the usefulness of liquid perfluorocarbon pads and choice of optimal fat suppression method

Purpose

To investigate whether image quality can be improved using liquid perfluorocarbon pads (Sat Pad) and clarify the optimal fat-suppression method among chemical shift selective (CHESS), water excitation (WEX), and short TI inversion recovery (STIR) methods in diffusion-weighted imaging (DWI) of the head and neck using 3-T magnetic resonance imaging. Correlations between results of visual inspection and quantitative analysis were also examined.

Material and Methods

This study was approved by our Institutional Review Board and informed consent was waived. DWI was performed on 25 subjects with/without Sat Pad and using three fat-suppression methods (6 patterns). Image quality was evaluated visually (4-point scales and lesion-depiction capability) and by quantitative analysis (signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR)). Two-way repeated-measures analysis of variance (ANOVA) was used to detect significant differences in scores of visual evaluation, SNR, and CNR.

Results

Mean visual evaluation scores were significantly higher with Sat Pad using STIR than without Sat Pad for all fat-suppression methods (P < 0.05). DWI with Sat Pad using STIR tended to be useful for depicting lesions. DWI using STIR showed reduced W-SNR (W: whole area of depicted structure) and CNR (between semispinalis capitis muscle and subcutaneous fat) due to fewer artifacts and uniform fat suppression.

Conclusion

Combining Sat Pad with STIR provides good image quality for visual inspections. When numerous artifacts are present and fat suppression is insufficient, higher SNR and CNR do not always provide good diagnostic image quality.