An investigation of the strength of branch areas in the piping of nuclear power installations

A three-dimensional shell finite-element method and a computer code have been developed in RRC ‘Kurchatov Institute’ for the strength analysis of branch pipe (nozzle) areas, which are among the most critical as regards strength components of pipes in both reactors and other systems. According to the method, the structure under study is broken up into eight-node isoparametric shell-type finite elements, each with eight or 18 integration points. The program was tested with the help of experimental results. The strength analyses of equal and unequal T-pipes were performed. Consideration was given to the variants with loading by pressure and moments (symmetric and asymmetric cases). The effects of fillet wall thickness and radius on the stressed state of the T-pipes were investigated.     

Comparison of glycine- and GABA-evoked currents in two types of neurons isolated from the rat striatum

Strychnine-sensitive glycine-activated currents and gamma-aminobutyric acid (GABA)-activated currents were compared in two types of neurons acutely isolated from striatal slices by vibrodissociation: large cells, presumably cholinergic giant aspiny neurons (GAN) and medium sized cells, presumed medium spiny neurons (MSN). Whole cell voltage clamp and concentration jump techniques were used. All cells responded to glycine (10-1000 microM) and GABA (2-100 microM), in MSN and GAN the maximal responses to glycine were 50 and 120% of the GABA response, respectively. GABA- and glycine- responses were additive and blocked selectively by bicuculline (1 microM) and strychnine (50 nM), respectively. These results predict the presence of alpha- and beta-subunits of the glycine receptor in the striatum.     

Anodic Dissolution of Cobalt Silicides in Alkaline Electrolytes

Anodic dissolution of cobalt silicides Co₂Si, CiSi, CoSi₂, CoSi₂–Si (eutectic alloy), and also individual Co and Si in 0.1–5.0 N NaOH solutions is studied by using cyclic voltammetry (CVA). In alkaline electrolyte, despite the increasing activity of silicon, the electrode is passivated due to the formation of protective films of cobalt oxides and hydroxides. The anodic stability of cobalt increases with a decrease in metal content.     

Temperature transitions and compatibility in gradient interpenetrating polymer networks

Traditional and gradient IPNs of various composition have been prepared from cross-linked polyurethane and poly(butyl methacrylate). For various layers of gradient IPN cut from the surface to the centre the glass transition temperatures and composition have been determined. The sorption of benzene vapour by various layers was measured, and from these data the free energy of mixing IPN components has been calculated. For all the layer compositions free energies of mixing are positive and dependent on the distance from the sample centre. This effect is thought to be connected not only with composition but with various conditions for phase separation in various layers. Each layer consists of two phases with their own glass transition temperatures. From these data, using the Fox equation, the composition of each phase for various layers have been calculated and the volume ratio of phase evolved was estimated.     

A biotechnology for the production of new biodiesel fuel

A new biotechnology for the production of biodiesel fuel on the basis of the lipids of filamentous fungi has been developed. The oleaginous mucoralean fungus, which produces up to 47.0–50.0% of lipids similar to rapeseed oil in their composition, are used as a producer. The duration of the fermentation process at 27–28°C is 4–5 days. The main characteristics of the biodiesel fuel based on fungal lipids satisfy the requirements of the basic standards, in particular, EN14214. The possibilities for creating a wasteless closedcycle technology based on the production of biodiesel and chitin in a single fermentation, applying stimulators for the germination of fungal conidia to reduce the duration of fermentations, and using glycerin formed in the synthesis of methyl esters as a source of carbon in a fermentation medium, along with wood hydrolyzates and the wastes of certain food plants in the fermentation process, are shown.     

Hydrogen production by electrochemical reforming of ethanol

The theoretical analysis of processes occurring in the solid oxide electrochemical reformer based on the oxide conductor with mixed ion-electron conductivity has been carried out. Three versions of the preliminary conversion of the initial fuel (ethanol), namely, partial oxidation, steam reforming, and recycling by the anode effluent gas mixture have been considered. The last version is shown to feature the highest fuel conversion efficiency and hydrogen yield.     

Metallothermic Reduction of Natural Cassiterite

Metallurgist - The process of phase formation during metallothermic reduction of tin and associated metals from natural cassiterite containing 74.4% SnO2, 16.3% SiO2, and 9.3% FeCO3 is studied by...     

Interphase Distribution of Elements during Two-Stage High Temperature Electrochemical Treatment of Lead-Bismuth Alloys

Metallurgist - Experimental simulation of the separation of the components of lead-bismuth alloy in a chloride melt is conducted. Using X-ray fluorescence, emission spectral and X-ray powder...