Effect of fiber length on the strength and fracture properties of a fiber-filled silicone composite

The mechanism by which fillers strengthen polymers is discussed, and the effect of fiber length on static and impact bending strength and on the area of the fracture surface is studied with reference to the example of a silicone composite. A correlation is established between the strength properties and the area of the fracture surface. On the basis of the data obtained it is shown that, as the fiber length increases, the fracture mechanism changes from extraction of the ends of the fibers along the fracture path to breakage of the fibers.Moscow Lomonosov Institute of Fine Chemical Technology. Ter-Gazaryan State Scientific-Research Planning Institute of Polymer Adhesives, Kirovakan. Translated from Mekhanika Polimerov, No. 3, pp. 445–449, May–June, 1971.     

Removing nitric oxide from flue gases by catalytic reduction

A Ti-W-V catalyst has been proposed for removing NO by means of ammonia reduction from flue gases from power stations and boiler systems operating with natural gas; it contains 10% W0₃ and 5% V₂O₅ deposited on anatase. The optimum NH₃/NO ration is 0.8. oxygen at levels of 0.1–7.8 vol. % does not affect the reduction of the NO. Industrial tests in flue gas from a power station show that the reduction of the NO is 96% at 240–270°C. The basic technological parameters have been determined.State Research and Development Institute for the Nitrogen Industry and Organic Synthesis Products, Moscow. Translated from Teoreticheskaya i Eksperimental'naya Khimiya, Vol. 27, No. 5, pp. 595–598, September–October, 1991. Original article submitted July 5, 1991.     

Effects of annealing atmosphere on the luminescent efficiency of ZnTe:O phosphors

The effect of the annealing atmosphere on the luminescent efficiency of ZnTe:O phosphors for X-ray imaging applications was studied. The phosphors were doped by ball-milling bulk ZnTe crystals in an O₂ atmosphere and annealed in various atmospheres: vacuum, N₂ or forming gas (95%N₂/5%H₂). All samples exhibited a deep red emission centered at 680 nm.The samples annealed in forming gas atmosphere exhibited an X-ray luminescent efficiency five times higher than the samples annealed in vacuum or N₂ atmospheres, which was attributed to the removal of surface tellurium oxides.