Radiation–Thermal Decomposition of Nitric and Acetic Acids in a Aqueous Nitrate Solution

The kinetics of radiation, thermal, and radiation–thermal decomposition of a mixture of nitric and acetic acids in water solutions of sodium nitrate is investigated under homogeneous conditions and with a solid phase introduced in the form of sandstone. The experimental data are used to calculate the temperature dependences of the rate of radiation, thermal, and radiation–thermal decomposition of the acids. The results obtained make it possible to calculate the dynamics of decomposition of acids for the conditions of deep burial of liquid radioactive wastes.     

Deterministic realization of nondeterministic computations with a low measure of nondeterminism

Various modifications of Turing machines and pushdown automata are considered. The complexity of nondeterministic computations with a low degree of nondeterminism is compared to that of deterministic analogs.Translated from Kibernetika, No. 2, pp. 7–15, March–April, 1991.     

Change in physicomechanical properties of steel D1604AT15 during fatigue at different loading frequencies

Results are presented in a statistical arrangement for studying the effect of loading frequency on the fatigue life in bending of plates with a stress concentrator. The nature of change in microhardness, electrical conductivity, dislocation density, and block dimensions during fatigue at frequencies of 2.8, 8.8, and 18 kHz has been demonstrated. It has been established that in spite of some qualitative difference the main indicators of fatigue at these frequencies are retained.S. M. Kirov Belorussian Technology Institute, Minsk. Translated from Problemy Prochnosti, No. 10, pp. 31–34, October, 1989.     

Dewatering of liwuid radioactive wastes in thin-film rotary evaporators

Translated from Atomnaya Énergiya, Vol. 67, No. 1, pp. 11–15, July, 1989.     

Applications of an Infrared Imager for Determining Temperature Fields in Gas Flows

A device containing a temperature converter with an infrared camera is described. Its application allows one to instantly measure the temperature field of a gas flow in regions of arbitrary sizes.     

Answers to Queries to Internet: An Optimal Generation Strategy

Representation of the answers to a query to Internet as a list of hypertext references to found objects is studied. Optimization of the strategy for choosing between static and dynamic references by criteria of server performance and reliability of information on an object is investigated. A probabilistic model is developed. Two strategies providing 100% reliability and admitting obsolete information with some probability are designed. Formulas for choosing a strategy are derived. Examples are given to illustrate their application to exponential distributions admitting an analytical solution. More complex distributions require the application of numerical methods of inverse Laplace transformation, integration, and optimization.     

Substantiation of the Radiochemical Characteristics of Liquid Radioactive Wastes That Determine Safe Operation of Deep Waste Disposal Sites

The qualitative and quantitative radiochemical composition of liquid wastes is substantiated. This makes possible further safe operation of deep waste disposal sites at the Mining-Chemical Plant and the Siberian Chemical Plant. The toxicity and temperature in a formation with the wastes removed are used as the assessment criteria, satisfaction of which guarantees that the wastes will remain localized within the assigned boundaries of the waste-disposal formation site. It is concluded that the standard limit should be imposed on the specific activity of the long-lived group of radionuclides – ⁹⁰Sr and ¹³⁷Cs – rather than on the total specific activity of the wastes placed in deep disposal sites. For maximum specific activity of ⁹⁰Sr and ¹³⁷Cs of 37 GBq/dm³ and total specific activity not exceeding 185 GBq/dm³ for buried wastes with radionuclide composition characteristic of modern radiochemical production operations, it is impossible for potentially dangerous radiation and thermochemical processes to occur in the waste-disposal formation site. The recommended limit permits reducing substantially the volume of buried wastes and therefore the region over which the wastes propagate in the deep disposal site.     

Novel microwave projection imaging for determination of internal structure

A novel microwave imaging technique based on the generalised weighted backprojection operator is introduced and tested using experimental data. Images of the internal structure of penetrable objects using this technique are compared and contrasted with images found from the classical back-projection method. It is demonstrated that the new method provides high-quality images of both discrete and continuous internal structure without the distortions characteristic of traditional methods.