Physicochemical Properties of Aspirated Dust in Production of Ceramic Pigments

The formation conditions and physicomechanical properties of dust emissions formed in the production of ceramic pigments are studied. Practical recommendations are given.     

Properties of R6M5 steel powders of various particle sizes and the structure of the steel in the sintered condition

Conclusions An investigation was carried out into the effect of particle size of powders produced by comminution of R6M5 high-speed steel waste (swarf) on their compressibility and sinterability. It is shown that with decreasing mean particle size the compressibility of such powders deteriorates, but their sinterability improves. The finer the steel powder, the lower is the sintering temperature necessary for the attainment of a given density. Varying the powder particles size brings about marked changes in the microstructure of the steel in the sintered condition. The liquid phase (ledeburitic eutectic) appearing during the sintering of steel powders of different particle sizes varies in form and distribution. With coarse powders (d_m=100 m) the eutectic is similar to that in cast steel, but with powders of small particle size (d_m=22 m) it is finer and evenly distributed throughout the structure in the form of thin lamellae.A 0.85%C-6% W-5% Mo-4% Cr-2% V (nominal composition) high-speed steel — Translator.The authors wish to thank A. N. Nikolaev of the Gorkii Polytechnic Institute for helpful discussion in the experimental part of the work.Translated from Poroshkovaya Metallurgiya, No. 6(234), pp. 9–15, June, 1982.     

Prospects for Using Nuclear Power Systems in Commercial Ships in Northern Russia

The experience gained over many years of operating nuclear-powered ice breakers in conquering the northern sea route is described. The conditions which must be met for year-round navigation of cargo ships in the Arctic are presented. For such navigation to be realistic, it must be profitable and Russian national interests in the region must be protected in accordance with the Maritime Policy of the Russian Federation for the period up to 2020. Information is also given concerning the technical status of operating nuclear-powered ice breakers and the characteristics of ice breakers and new-generation nuclear power systems.     

Ellipsometric control of the parameters of lead selenide films during oxidation

The changes in the optical characteristics of lead selenide thin films with different degrees of oxidation are investigated using ellipsometry. It is found that, as the degree of oxidation increases, the refractive index, the optical thickness, and the extinction coefficient of lead selenide films decrease monotonically, whereas the effective film thickness increases. The composition of the films can be determined from the measured refractive index at a wavelength λ = 632.8 nm with the use of the dependences calculated on the basis of the single-layer model.     

An examination of the role of plasma treatment for lean NOx reduction over sodium zeolite Y and gamma alumina Part 1. Plasma assisted NOx reduction over NaY and Al2O3

The role of plasma processing on NO_x reduction over γ-alumina and a basic zeolite, NaY was examined. During the plasma treatment NO is oxidized to NO₂ and propylene is partially oxidized to CO, CO₂, acetaldehyde, and formaldehyde. With plasma treatment, NO as the NO_x gas, and a NaY catalyst, the maximum NO_x conversion was 70% between 180 and 230 °C. The activity decreased at higher and lower temperatures.

As high as 80% NO_x removal over gamma alumina was measured by a chemiluminescent NO_x meter with plasma treatment and NO as the NO_x gas.

For both catalysts a simultaneous decrease in NO_x and aldehydes concentrations was observed, which suggests that aldehyde may be important components for NO_x reduction in plasma-treated exhaust.