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The Cambria cogeneration plant of Air Products and Chemicals, Inc. utilizes a pair of circulating fluidized bed (CFB) boilers to produce steam for export and energy generation. The plant is subjected to disturbances called sootblows which use steam to clear the built-up ash on the heat transfer surfaces of the convection sections of the boilers. Sootblows impart disturbances to the temperature and pressure of the steam in the main header leading to the steam turbine, resulting in increased variance in the power output of the turbine/generator and additional mechanical stresses on the equipment. An effort was undertaken to dynamically model the effects of the sootblow and to devise a control scheme to eliminate its effects on the main steam pressure and temperature.

We report here on low temperature magnetic relaxation in the erbium orthoferrite ErFeO 3 . The variation of magnetic viscosity, S ≡ ∂M / ∂ / ∂ ln t , with temperature shows three different regimes below 40 K. The most remarkable is that at T ≤ 3 K where S(T) remains constant suggesting the occurrence of macroscopic quantum tunneling of the magnetization.

Electret-forming polymers of vinyl-pyridine and vinyl-quinoline monomers have been synthesized and chemically doped under different conditions, with subsequent structural studies by X-ray diffraction, SEM, EDX-quantitative analysis, DSC, FT-IR, EPR, Mossbauer and other techniques. The results establish some synthesis-structure-doping correlations which are clues to be used in analysing the work in progress on their electric properties.

This paper describes the preparation of rutile-type V/Sb mixed oxide (vanadium antimonate) with the ball-milling (mechano-chemical) method starting from single metal oxides, as well as the comparison with a similar system prepared by the co-precipitation method. Samples were tested as catalysts for the gas-phase ammoxidation of propane to acrylonitrile. The mechano-chemical method allowed the preparation of the rutile-type mixed oxide characterized by smaller crystallite size than the catalyst prepared by co-precipitation and calcined at 450 °C. The calcination at 700 °C of the sample prepared by the mechano-chemical method led to a crystalline vanadium antimonate characterized by a higher concentration of cationic defects than the corresponding calcined sample prepared by co-precipitation. This led to a considerably higher activity in propane ammoxidation, but to a lower selectivity to acrylonitrile.