treatment of acetyl- 1,4-benzoquinone with isoprene gave the corresponding regioselective adduct (i). rearrangement of the adduct (1) in pyridine and methanol gave 2-acetyl-5, 8-dihydro-6-methyl- 1,4-dihydroxynaphthalene (2). silver oxide oxidation of the rearranged product (2) gave 2-acetyl-5,8-dihydro- 6-methyl- 1,4naphthalenedione (3). regioselective addition of trans-piperylene to this comp...

Clinical manifestations appearing in labourers working with manganese in various industrial fields were discovered about 125 years ago. Couper in 1837 was the first to report the appearance of a peculiar neurological picture similar to Parkinson's shaking palsy in five men grinding manganese dioxide in France. Forty-two years later, Schlockow (1879) reported another 42 cases. In addition von Ja...

Supported manganese oxide catalysts were prepared by the impregnation of alumina foam blocks washcoated with alumina and silica. The manganese content based on the weight of the washcoats was 10 wt % calculated as MnO2. Fourier transform profiles of the Mn K-edge EXAFS spectra for these samples gave three distinctive peaks at 0.15, 0.25, and 0.32 nm and were close to the profiles of Mn3O4 and b...

A simplified 5-RC transmission line equivalent circuit was introduced. Manganese dioxide cathodes from three commercial primary alkaline cells were investigated by means of ac impedance technique. Cathode Ohmic resistance, Faraday resistance for the reduction of MnO2, proton diffusion rate inside the lattice of EMD and electrochemical accessible surface area were obtained by numerical fitting o...

Industrial exposure to gases and fumes may produce a wide variety of respiratory damage including tracheobronchial inflammation and parenchymal damage.' Tracheobronchial inflammation is reported, particularly after exposure to chlorine, ammonia, and sulphur dioxide. Interstitial pneumonitis has been associated with the inhalation of oxides of nitrogen,2 cadmium,3 manganese,4 mercury,5 and resin...

Washed Mycoplasma organisms died rapidly when suspended in 0435 yo (w/v) NaCl prepared in laboratory ‘distilled’ water (steam condensate) at room temperature; this rapid killing was decreased by adding to the suspensions certain chelating agents, reducing agents or finely ground manganese dioxide. Washed organisms survived well in potassium phosphate (K,HPO,, 0.01 M adjusted to pH 7) dissolved ...

The proton diffusion coefficients in an electrolytic manganese dioxide (EMD) electrode at various stages of the constant current discharge have been determined by means of AC impedance technique. The finite diffusion model was applied in the numerical fitting. The crystallite size of EMD was estimated from (1 1 0), (1 2 1) and (0 2 1) diffraction peaks with both Scherrer equation and Warren–Ave...

Bisphenol A (BPA), an environmental contaminant with weak estrogenic activity, resists microbial degradation under anoxic conditions but is susceptible to abiotic transformation by manganese dioxide (MnO2). BPA degradation followed pseudo-first-order kinetics with a rate constant of 0.96 (±0.03) min(-1) in the presence of 2 mM MnO2 (0.017% w/w) at pH 7.2. 4-hydroxycumyl alcohol (HCA) was the ma...