Sumitomo Chemical (United Kingdom)

CoCr2O4 is a spinel-type oxide that has attracted attention due to its relatively narrow band gap and multivalent redox capability. Here, we investigate how calcination temperature affects the dye-degradation performance of CoCr2O4 nanoparticles prepared via a hydrothermal route. CoCr2O4 calcined at 500 °C (CCO-500) shows the best activity under visible light, achieving 97% removal of malachite green within 2 h. Increasing the calcination temperature improves crystallinity but decreases cation inversion, yielding an optimum at 500 °C. High removal efficiencies (>85%) are also obtained for methyl orange, crystal violet, and acid orange 7, indicating broad applicability. Notably, CCO-500 exhibits pronounced Fenton-like activity in the dark, attributed to Co2+/Co3+ redox cycling associated with cation inversion, which promotes H2O2 activation and formation of reactive oxidizing species. The catalyst is recyclable, maintaining 85% efficiency after five runs. These results identify CoCr2O4 nanoparticles as versatile catalysts coupling visible-light photocatalysis with Fenton-like oxidation for aqueous environmental remediation.

Electric field control of magnetization is expected to be utilized for energy-efficient nonvolatile magnetic memory application. $\mathrm{C}{\mathrm{o}}^{3+}$-substituted $\mathrm{BiFe}{\mathrm{O}}_{3}$ (BFCO) exhibits both ferroelectric polarization ($\ensuremath{\sim}100\phantom{\rule{4pt}{0ex}}\textmu{}\mathrm{C}/\mathrm{c}{\mathrm{m}}^{2}$) and the spin canting induced weakly ferromagnetic moment ($\ensuremath{\sim}0.03\phantom{\rule{4pt}{0ex}}{\textmu{}}_{B}/\phantom{\rule{4pt}{0ex}}\mathrm{f}.\mathrm{u}.$) perpendicular to each other at room temperature. Magnetization reversal by electric field was observed in a BFCO thin film. In our previous theoretical calculation, spin canted collinear structure having a weak ferromagnetic moment was stabilized when high-spin $\mathrm{C}{\mathrm{o}}^{3+}$ was substituted in $\mathrm{BiFe}{\mathrm{O}}_{3}$. To confirm the presence of high-spin $\mathrm{C}{\mathrm{o}}^{3+}$ in BFCO, the pressured-induced spin-state transition of $\mathrm{C}{\mathrm{o}}^{3+}$ was investigated by first-principles calculations and Co $K\ensuremath{\beta}$ synchrotron x-ray emission spectroscopy. We investigated the spin state of $\mathrm{C}{\mathrm{o}}^{3+}$ during the pressure-induced structural transition from $R3c$ to Pnma. As a result, a pressure-induced transition from high-spin to low-spin $\mathrm{C}{\mathrm{o}}^{3+}$ was predicted. Moreover, the presence of high-spin $\mathrm{C}{\mathrm{o}}^{3+}$ at ambient pressure was confirmed in $\mathrm{BiF}{\mathrm{e}}_{0.8}\mathrm{C}{\mathrm{o}}_{0.2}{\mathrm{O}}_{3}$ by observing the decrease of $K{\ensuremath{\beta}}^{\ensuremath{'}}$ peaks of Co $K\ensuremath{\beta}$ x-ray emission spectra under pressure. This study provides evidence that the weak ferromagnetism of BFCO is attributed to high-spin $\mathrm{C}{\mathrm{o}}^{3+}$ and provides insight that may help to enhance weak magnetization by substitution of other elements.

Ants (Hymenoptera: Formicidae) are social insects and important pests in the urban environment. The main groups of pest ants in the urban environment are leafcutter and house ants. Leaf-cutter ants cause crescent-shaped defoliation of plants, where in the urban environment it causes problems in gardens and ornamental plants. Domestic ants cause human health problems, contaminate food and cause problems in equipment and buildings. In this work, we propose an integrated ant management program in urban environments. For that, a bibliographic review was carried out addressing the following topics: life cycle of ants, main groups of pest ants, factors that influence their attack, decision-making systems, management strategies and tactics. It is observed that ants are pests that are difficult to control, and successful control is related to the correct execution of the various components of integrated pest management. Regarding control tactics, chemical control is the main method used to control ants in urban environments because the effectiveness of other methods (ie, biological and behavioral control) is poor.

The paper describes a new design of Class E oscillator that can switch between two oscillation frequencies while maintaining high efficiency at both frequencies. The oscillator is designed based on a class E amplifier with an output circuit that satisfies the conditions of class E at two frequencies. The feedback circuit allows the change of capacitor to switch between two operating frequencies. Calculation, modeling and experimental study of the oscillator at frequencies of 4.5 and 5 MHz are presented.

Nickel-catalyzed N-arylation reaction of N-trimethylsilyl-carbazole using aryl bromides is found to proceed in the presence of sodium acetate, giving N-aryl-carbazoles in high yields. Under these conditions, N-trimethylsilyl-carbazole could react with aryl bromides selectively even in the presence of other N-trimethylsilyl-amines or N-H-amines. This arylation reaction was applied to the polymerization to provide a polycarbazole.

[abstFig src='/00290001/05.jpg' width='300' text='Schematic of the proposed system for actively localizing the sound source' ] Animals use two ears to localize the source of a sound, and this paper considers a robot system that localizes a sound source by using two microphones with active external reflectors that mimic movable pinnae. The body of the robot and the environment both affect the propagation of sound waves, which complicates mapping the acoustic cues to the source. The mapping may be multimodal, and the observed acoustic cues may lead to the incorrect estimation of the locations. In order to achieve sound source localization with such multimodal likelihoods, this paper presents a method for determining a configuration of active pinnae, which uses prior knowledge to optimize their location and orientation, and thus attenuates the effects of pseudo-peaks in the observations. The observations are also adversely affected by noise in the sensor signals, and thus Bayesian inference approach to process them is further introduced. Results of experiments that validate the proposed method are also presented.

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A fractal method is applied to a measurement technique for complicated patterns of floc in a wastewater treatment process in this study. A fractal dimension is calculated in a simple procedure using online sampled image data taken by ITV camera in a flocculation process. The image data indicate complicated patterns and they are numerated with the fractal dimension. The more complicated the pattern is, the bigger the fractal dimension is. When the fractal dimension is maximum, the density and the size of floc are also maximum, and the water content of floc is minimum. Experimental data testify that the proposed fractal method is useful for the wastewater treatment process in a food producing factory. >

An actinomycete strain SC-4710, a new soil isolate, was found to produce a new macrolide antibiotic, PC-766B. Chemotaxonomic analysis of the producing organism revealed that the cells of SC-4710 had type IV cell wall, type A whole cell sugar pattern, type PII phospholipids, menaquinone MK-8(H4), cellular fatty acids comprising straight-chain saturated, unsaturated and tuberculostearic acids, and mycolic acids. The strain was identified as Nocardia brasiliensis (Lindenberg) Pinoy. The antibiotic, PC-766B, was active against Gram-positive bacteria, and some fungi and yeasts, but inactive against Gram-negative bacteria. It also showed antitumor activity against murine tumor cells in vitro and in vivo, and a weak inhibitory activity against Na+, K(+)-ATPase in vitro.

To assess the toxicological significance of thyroidal tumor observed slightly in a long-term rat study with diniconazole, (E)-1-(2,4-dichlorophenyl)- 4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol, a 3-month subacute feeding study was conducted in male Crj: CD (SD) rats by administering diniconazole in diet at concentrations of 0, 100, 1,000, or 2,000 ppm. Examinations mainly for thyroid functions were performed at Weeks 2, 4 and 13. Measurement of serum hormone levels revealed continuous decreases in serum thyroxine (T4) and free T4 levels at and above 1,000 ppm and increase in serum thyroid stimulating hormone (TSH) level at 2,000 ppm concurrently with liver weight and hepatic UDP-glucuronyltransferase (UDP-GT) increases at and above 1,000 ppm. No changes were observed in serum triiodothyronine (T3) and free T3 levels. Increase in thyroid uptake of 125I and organification of 125I in the thyroid at 2,000 ppm and thyroid follicular cell hyperplasia at and above 1,000 ppm were also observed. However, no compound-related changes were observed in autopsy and organ weight in the thyroid. Based on the above results, diniconazole induces increases in the hepatic UDP-GT activity and the thyroid hormone excretion from the liver. The increased excretion of thyroid hormones causes decrease in serum T4 and free T4 levels, triggering the feedback mechanism of the pituitary gland, promotion of TSH release from the pituitary gland and increase in serum TSH level. The increased serum TSH level probably leads to increased 125I uptake of thyroid and thyroid follicular cell hyperplasia. Thus, the thyroid tumorigenesis in rats treated with diniconazole is due to the secondary overstimulant effect on the thyroid by increased serum TSH level. The toxicological significance in humans is extremely low and it is unlikely that diniconazole would increase thyroid tumor in humans even if diniconazole were to alter normal thyroid hormone level in humans.