Analysis of the Operating Conditions of a Continuous Linear Crystallizer

Theoretical Foundations of Chemical Engineering - The operation of a linear crystallizer, which performs crystallization extraction of uranium from a nitric acid solution of uranyl nitrate during...     

Study of the Possibility of Preparing Low-Cement Magnesia Concretes

Refractories and Industrial Ceramics - The possibility of producing vibro- and self-flow low-cement periclase concretes is investigated. It is shown that when the concrete mixture is prepared in...     

Synthesis of Spinel from Caustic Magnesite and Alumina Dust

The sintering of a mixture of a caustic dust and an alumina dust collected from electric filters taken in MgO/Al₂O₃ ratios of 0.1, 0.28, 0.5, and 0.75 at 1650°C is studied. Materials with superior physicomechanical properties are obtained: open porosity, 1.2 – 8.4%; density, more than 3.5 g/cm³, and compressive strength, 160 – 410 MPa. High-density pellets (free of additions) are prepared at a MgO/Al₂O₃ ratio of 0.75, with compressive strength as high as 160 MPa.     

Some properties of materials in the MgCr2O4-MgAl2O4 system

Conclusions We studied the relationships between the average sizes of the crystallites, the specific surface and the nature of the porosity and the composition and temperature of synthesizing powdered materials in the system MgCr₂O₄-MgAl₂O₄ and also the linear shrinkage during sintering of specimen prepared from the materials. It is shown that the relationships are nonlinear and their extremes correspond to the compositions close to MgCrAlO₄.Translated from Ogneupory, No. 3, pp. 13–15, March, 1988.     

Radiation-epidemiological studies of thyroid cancer incidence in Russia after the Chernobyl accident (estimation of radiation risks, 1991-2008 follow-up period)

This study presents an analysis of the thyroid cancer incidence in the population of the most contaminated territories of Bryansk, Kaluga, Oryol and Tula oblasts affected by the Chernobyl accident. The follow-up period is 1991-2008, and the cohort size is 309 130 people. For that period 978 thyroid cancer cases were detected. The excess relative risk per 1 Gy (ERR/Gy) is found to be statistically significant for children and adolescents (0-17 y of age) at the time of the Chernobyl accident (ERR/Gy=3.22; 95 % confidence interval (1.56; 5.81). In boys, the ERR/Gy was higher than in girls -6.54 and 2.24, respectively. A statistically significant decrease in ERR/Gy with time since exposure, by a factor of 0.37 per 10 y, was observed for the whole cohort and for boys separately, but not for girls. No radiation risks of a thyroid cancer among people of 18 y of age at exposure and older were found.     

Ways of improving pneumatic transport throughput

Comparative equipment indices are given for transporting cement. An operating principle is proposed for a chamber feeder without aeration devices, i.e. with use of an injector for compressed air supply from openings directed at the bottom of the reception chamber. Material movement is demonstrated over an inclined plane with charging of a chamber feeder. Injector channel length, the dependence of channel length on its inclination and width of the sprayer channel slot, are determined.