The influence exerted by some anionic surfactants towards the corrosion process of an Agcontaining aluminium alloy (AA2139) is studied during 168 h immersion in 0.01 M NaCl solution. This behaviour is compared with that previously determined on a Li-containing alloy (AA2198). The surfactants, at a proper concentration, hinder anodic and cathodic reactions as well as the pitting process, but the...

1. Methyl retinoate has been converted into methyl 5,6-monoepoxyretinoate by reaction with monoperphthalic acid. The epoxy acid ester on alkaline hydrolysis gave 5,6-monoepoxyretinoic acid. 2. Treatment of the 5,6-monoepoxy compounds with ethanolic hydrochloric acid gave the corresponding 5,8-epoxy (furanoid) compounds. 3. With lithium aluminium hydride, the acid and the ester groups were selec...

The galls of the Quercus infectoria (QI) tree are traditionally believed to have great medicinal value. Pharmacologically the galls are claimed to have various biological activities such as astringent effect, antidiabetic, antitremorine, local anaesthetic, antipyretic, anti-inflammatory, antibacterial, antiviral and many more. These pharmacological activities of gall extracts were reported to b...

The present work demonstrates that friction stir welding (FSW) is a feasible route for joining 6061 aluminium (Al) alloy to AISI 1018 steel. The weld has a good weld quality and is free of cracks and porosity. The tensile failure happened at the boundary between the nugget and thermomechanically affected zone of the base Al alloy, indicating that the weld has a higher joining strength. Despite ...

The reduction of aluminium trichloride by lithium aluminium hydride in the presence of poly(vinylpyrrolidone) or poly(methylmethacrylate) in mesitylene yielded nano aluminium particles in the matrices of respective polymers. Solution phase synthesis methodology was used successfully to produce composites of various Al/polymer ratios. The composites were characterized by powder XRD patterns and ...

The aluminium alloys are more frequently used in automotive industry especially as an alternative material for car-bodies. In this article the comprehensive summary concerning technology of resistance spot welding of aluminium alloys was presented. The welding schedules, electric parameters of welding, electrodes materials and electrodes life time by resistance spot welding aluminium were descr...

Samples of layered double hydroxides were prepared by a sol-gel procedure. Quinolinate Al(C9H6NO)3 units were added during the synthesis, leading to composite quinolinate hydrotalcite-like compounds. The amount of quinolinate was varied, showing that the number of organic building blocks determines the physicochemical properties of materials, which differ significantly from those commonly repor...

Nearly all metals, with the exception of gold and platinum, will corrode in an oxidising environment forming compounds such as oxides, hydroxides and sulphides. The degradation of metals by corrosion is a universal reaction, caused by the simple fact that the oxide of a metal has a much lower energy than the metal itself. Hence there is a strong driving force for the oxidation of metals. For ex...

Bulk aluminium nitride (AlN) is a very promising substrate material for UV optoelectronics based on AlGaN ternary compounds. AlN single crystals exceeding 1'' in diameter can now be grown by physical vapour transport (PVT). UV transparency is of high interest for UV devices designed to emit through the substrate. We report on 500 μm thick bulk AlN substrates with plain UV transmittance of 50% (...

The aim of the study was to evaluate the protective status of an antioxidant combination (melatonin and Sempervivum tectorum extract) on aluminium accumulation in genital organs of male rats. The 12 weeks study was carried out on 35 Wistar male rats divided in five groups: C – control, receiving distillated water; E1 – aluminium sulphate 0.1 mg/L; E2 – melatonin 10 mg/kg b.w. in drinking water;...