Mono-aryloxy or mono-alkoxy zirconium complexes/methylaluminoxane catalyst system in ethylene polymerization

Summary Mono-aryloxy zirconium complexes 1–6 or mono-alkoxy zirconium complexes 7–10 were prepared and the ethylene polymerization was carried out in the presence of these complexes/methylaluminoxane. Steric factor of the aryloxy and alkoxy ligands in the complexes remarkably influenced on activity of ethylene polymerization.     

Faradaic impedance to analyze charge recombination in photoelectrode of dye-sensitized solar cell

Charge transfer on the photoelectrode of dye sensitized solar cell (DSC) is composed of the various processes as follows: photoexcitation of electron in the dye; electron injection from the excited dye into the conduction band of oxide semiconductor; electron diffusion in the oxide semiconductor, reaction between oxidized dye and iodide ions (I⁻); and charge recombination. The charge recombination is one of the main factors that limit the efficiency of photoelectric conversion at photoelectrode. It is well known that 4-tert-butyl pyridine (TBP) is the useful additive in order to suppress the charge recombination. The authors fabricated the DSC with two photoelectrode materials such as titanium dioxide (TiO₂) and zinc oxide (ZnO), and analyzed the charge recombination by using electrochemical impedance spectroscopy. Theoretical equation of Faradaic impedance was derived from the reaction model of photoelectorde, and the charge transfer resistance of the photoelectrode was defined from the Faradaic impedance. In addition, the influence of the charge recombination on the impedance spectrum of the photoelectrode was discussed by the comparison between simulated and experimental results.     

Concentration in plasma and excretion in milk of lactating cows after oral administration of tribromsalan, oxyclozanide and bromofenofos

The fasciolicides tribromsalan (TBS), oxyclozanide (OCZ) and bromofenofos (BFF) were orally administered to three lactating cows. The concentrations of TBS, OCZ and the BFF metabolite dephosphate bromofenofos (DBFF) in plasma, and the excretion of these compounds in milk were determined by high-performance liquid chromatography. In plasma, the concentrations of TBS, OCZ and DBFF reached maximum at about 1.0 day and the compounds remained detectable until 5.7, 7.4 and 15.1 days after administration, respectively. The detection limits of these compounds in plasma were 10, 2 and 2 ppb, respectively. In milk, the concentrations of TBS, OCZ and DBFF reached maximum at about 24 hours and the compounds remained detectable until 30-47, 30-47 and 78-119 hours after administration, respectively. The detection limits of these compounds in milk were 5.1 and 1 ppb, respectively. The residence times of TBS and BFF were very close to the withdrawal times of the fasciolicides.     

Electroless plating of aluminum using diisobutyl aluminum hydride as liquid reducing agent in room-temperature ionic liquid

We investigated an electroless aluminum plating based on using AlCl₃–1-ethyl-3-methylimidazolium chloride (AlCl₃–EMIC) ionic liquid with diisobutyl aluminum hydride (DIBAH) as a liquid reducing agent. The plating film was analyzed by measurements of X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX) and glow discharge optical emission spectroscopy (GD-OES). Consequently, a thick aluminum plating film with high uniformity was prepared from AlCl₃–EMIC with DIBAH. No impurity phases were detected. Moreover, we discussed the reaction mechanism of the electroless aluminum plating.