The laminar organization of the afferent connections of the cortical column in field 17 in the cat

The laminar structure of the cortical column connections in area 17 of the cat was studied using the microiontophoretic injection of the horseradish peroxidase. Following the enzyme injection in one column at different depths below the cortical surface the identification of morphological types of labelled neurons and the estimation of their localization were performed. When enzyme has been delivered in the whole depth of the column pyramidal neurons labelled were found in upper (I/III) and lower (V/VI) layers (ratio II;I). When the depth of enzyme injection exceeded the cortex width the cells in layer IV were labelled as well. The ratio between the quantity of cells labelled in upper and lower layers was preserved. (II; I). After the enzyme injection in the upper part of the column labelled cells were found mainly in the upper layers. It is concluded that the neurons of the column of have extensive (up to 5 mm), predominantly horizontal afferent connections with the cells in upper and lower layers while the connections with neurons in layer IV are local and do not extend beyond 0.5 mm.     

Growth of almost filled axial-symmetric hydraulic fracture under small and great leakages

A system of dimensionless equations depending on a single parameter is obtained. The system describes a developed horizontal circular crack caused by hydraulic fracturing and propagating in permeable elastic medium. Some cases of small and great leakages are investigated.Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 3–13, May–June, 2004.     

Application of ultrasound in the investigation of magnetic relaxation effects in a ferromagnet

Experimental results are given from an investigation of the magnetic relaxation of samples by the ultrasonic method.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 48, No. 2, pp. 326–330, February, 1985.     

Analyzing the aerodynamic structure of swirl flow in vortex burner models

The article presents the results from experimental and numerical investigations of the parameters characterizing large-scale vortex structures formed in the models of various burners with flow swirling. The experiments included flow visualization and velocity field measurements carried out using a modern contact-less diagnostic system constructed on the basis of a laser Doppler anemometer. In addition, the frequency responses of unsteady vortex flow modes were investigated using dedicated acoustic sensors. The distribution of static pressure induced by an unsteady vortex was obtained using the phase averaging method. Along with experiments, the swirl flow parameters were calculated using an analytic theory and the Star CCM+ commercial software package. The adequacy of the mathematical modeling results was checked by comparing them with the physical experiment data.     

Achieving more reliable operation of turbine generators at nuclear power plants by improving the water chemistry of the generator stator cooling system

Ways of improving the water chemistry used in the turbine generator stator’s cooling systems at Russian nuclear power plants are considered. Data obtained from operational chemical monitoring of indicators characterizing the quality of cooling water in the turbine generator stator cooling systems of operating power units at nuclear power plants are presented.     

Binding of anionic surface-active substances by water soluble humic acids

The interaction of anionic SAS with water-soluble humic substances has been studied. The quantitative characteristics of this interaction (binding constants) were calculated and the impact of various factors on the specified interaction was estimated. The binding of anionic SAS by humic substances was found to depend on the contact duration, ambient temperature, concentration, the nature, and size of molecules of humic substances, and also on the nature and length of the hydrocarbon radical of ASAS molecules.     

Pt/C electrocatalysts based on the nanoparticles with the gradient structure

The architecture of bimetallic nanoparticles has strong influence on durability and activity of PtM/C electrocatalysts in the oxygen electroreduction (ORR) and the methanol electrooxidation reactions (MOR). In the present study the Pt_0.8(Cu)/C electrocatalyst was obtained by the methods of successive multistage reduction of platinum and copper from the solutions of their precursors while platinum concentration in the matrix solution was increasing step by step. The composition, structural characteristics and electrochemical behavior of this material were compared with the Pt_1.0Cu/C catalyst based on the nanoparticles of a solid solution, which was obtained by the combined single-step chemical reduction of precursors, as well as with a commercial Pt/C sample with the same Pt-loading (20% by weight). The catalyst based on the Pt–Cu gradient nanoparticles demonstrated the highest corrosion-morphological stability in the stress-test, as well as the highest activity in ORR and MOR in the HClO₄ solutions. Both of the studied bimetallic catalysts lose a significant amount of copper during the standardizing cycling and the stress-test. In the stabilized composition of the “gradient catalyst” the residual copper content, however, is considerably higher than that of the catalyst with the solid solution nanoparticles. The positive features of the electrochemical behavior of Pt_0.8(Cu)/C catalyst arise apparently due to the faster formation of a durable protective layer of platinum on the surface of nanoparticles in the process of functioning, compared to the analogue based on the nanoparticles of the solid solution. High stability and activity of Pt_0.8(Cu)/C compared to the Pt/C analogue are associated with the larger size of the nanoparticles and the promoting influence of residual copper on the catalytical activity of platinum.     

Nanocluster initiation of combustion of off-grade hydrocarbon fuels

We have performed large-scale experiments on burning, in the regime of nanocluster pulsating combustion, such off-grade fuels as straw oil, hydrocarbon fuel, exhaust crankcase waste, crude oil, and others on the laboratory prototype of the self-contained burner of the Institute of Thermal Physics, Siberian Branch of the Russian Academy of Sciences. The application of modern diagnostics has made it possible to obtain a large body of information on the features of the physicochemical processes of such combustion in the presence of superheated steam. The experimental and theoretical studies have shown that as a result of the heterogeneouscatalytic decomposition of water molecules on soot nanoclusters in the mixing zone, high concentrations of the OH radical are formed and that this decomposition can be effective on carbon particles of size 1–5 nm at temperatures characteristic of traditional flares. The generation of an active OH radical leads to a significant increase in the rates of chemical reactions and a stable high-temperature combustion of "heavy" fuels with the observance of ecological norms.