Dewatering of liwuid radioactive wastes in thin-film rotary evaporators

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

Polarisation transformer on Ti:LiNbO3 with reset-free optical operation for heterodyne/homodyne receivers

Experimental results for an integrated-optical state-of-polarisation (SOP) controller device on Ti:LiNbO3 for continuous broadband optical operation, with small temperature sensitivity and the possibility of integration with polarisation- insensitive directional couplers, are presented.     

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.     

Functional of Receptor Sensitivity and Adjoint Equations

The functional of receptor sensitivity of a territory to the disposition of emission sources can adequately be calculated with the use of the mathematical apparatus of adjoint equations. The solutions of these equations allow one to determine the action of pollutants in the form of aerosols or harmful gaseous impurities on the environment and human health. Examples of calculation of the sensitivity functional on the basis of solution of adjoint equations have been presented. Mathematical models for the typical equations on optimum placement of industrial plants have been formulated. An interpretation of the results obtained has been given.     

Stability in an evaporating chain of identical droplets

Stability has been examined for an ordered chain of monodisperse droplets under vacuum, which interact one with another via the evaporating molecules.Translated from Inzhenerno-fizicheskii Zhurnal, Vol. 60, No. 4, pp. 656–660, April, 1991.     

AC hot-carrier effects in MOSFETs with furnaceN2O-nitrided gate oxides

AC hot-carrier effects in n-MOSFETs with thin (~85 Å) N₂O-nitrided gate oxides have been studied and compared with control devices with gate oxides grown in O₂. Results show that furnace N₂O-nitrided oxide devices exhibit significantly reduced AC-stress-induced degradation. In addition, they show weaker dependences of device degradation on applied gate pulse frequency and pulse width. Results suggest that the improved AC-hot-carrier immunity of the N₂O-nitrided oxide device may be due to the significantly suppressed interface state generation and neutral electron trap generation during stressing     

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.     

Apparent thermal conductivity of evacuated SiO2-aerogel tiles under variation of radiative boundary conditions

The apparent thermal conductivity λ of evacuated SiO₂-aerogel tiles was measured with our small guarded hot plate vacuum system LOLA II. In order to study the influence of the boundary emissivity on λ the plates (20 × 20 cm²) were either used with their plasma-sprayed surfaces ( ≈ 0.5) or with low-emissivity aluminum ( ≈ 0.05) foils as covers. The difference in the apparent conductivity already showed at room temperature and rose to about 50% for radiative temperatures T_r = 570 K. An important consequence is that superinsulating SiO₂-aerogel systems should always be provided with low-emissivity boundaries around the aerogel. The calorimetric results for λ are compared with radiative conductivity values derived from spectral i.r. transmission measurements.     

A strain hardening failure assessment diagram derived from carbon-manganese steel compact tension specimens

A failure assessment diagram is derived from carbon-manganese steel compact tension specimens. The diagram has been determined from an elastic-plastic finite element analysis of a compact tension specimen geometry. The diagram has been validated by using experimental fracture toughness data obtained on the same steel and specimen geometry modelled in the finite element analysis. The plastic collapse load has been determined empirically for this geometry.It is shown that a non-work-hardening failure assessment diagram is not a good representation of the experimental data and that the computed failure assessment diagram is more appropriate for describing the behaviour of the carbon-manganese steel specimens.