Vapor phase synthesis of nanofibrous carbon materials from water-ethanol mixtures

We present a detailed study of the pyrolytic synthesis of nanofibrous carbon materials (NCMs) from ethanol and various water-ethanol mixtures on a nickel catalyst at temperatures from 400 to 700°C. In the synthesis from 96% ethanol, the initial deposition rate increases with temperature, but this is accompanied by a substantial decrease in catalyst life. The addition of water to the reaction system considerably increases the catalyst life. One possible reason for this is that water vapor prevents carbonization of the catalyst particles. At the same time, above 600°C the rate of NCM deposition from a 50% water-ethanol mixture is considerably slower. At 550°C and lower temperatures, the rate of NCM deposition from water-ethanol mixtures (based on ethanol consumption) changes insignificantly. Our results demonstrate that NCMs can be synthesized even from very dilute (down to 10 vol %) aqueous ethanol solutions. The participation of water vapor in chemical processes that take place in the reaction zone is discussed.     

Extraction of lactic acid from technological (concentrated) solutions

The extraction of lactic acid from technological solutions by different extracting agents and their mixtures was studied. It was established that the most effective extraction of lactic acid is reached in systems with mixtures of trioctylamine and tributyl phosphate. The reextraction of lactic acid from the organic phase is performed by water.     

Nanosized cobalt ferrite powders obtained by pyrolytic extraction

Heterostructures were prepared from MSM molecular sieves and magnetic materials by extraction pyrolysis. The molecular sieves were filled with solutions of extracts and heated to remove the organic phase and form an inorganic material. The annealing and dissolution of the MSM-41 molecular sieve gave nanosized cobalt ferrite powder with particles of 40 nm and a coercive force 5000 Oe.     

Molecular alterations in early gastric carcinomas. No apparent correlation with Helicobacter pylori status

The effect of nitric oxide (NO) donors on high-voltage-activated Ca2+ channels in insulin-secreting RINm5F cells was investigated using the patch-clamp technique in the whole-cell configuration. Sodium nitroprusside (SNP, 2-400 microM) induced a dose-dependent reduction in Ba2+ currents with maximal inhibition of 58%. The IC50 for SNP was 45 microM. A different NO donor, (+/-)S-nitroso-N-acetylpenicillamine (SNAP, 500 microM), also produced a 50% decrease in current amplitude. When 200 microM SNP was administered together with the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidozoline-1-oxyl-3-oxide (carboxy-PTIO, 300 microM), the Ba2+ current inhibition was lowered to 7%. Administration of 500 microM 8-bromoguanosine 3':5'-cyclic monophosphate sodium salt (8-Br-cGMP) mimicked the effects of SNP, causing a comparable decrease (56%) in peak-current amplitude. When soluble guanylyl cyclase was blocked by 10 microM 1H-[1,2, 4]oxadiazole[4,3-a]quinoxalin-1-one (ODQ), the inhibitory effect of 200 microM SNP was reduced from 39% to 15%. The SNP-induced current decrease was 36% of controls after the blockade of L-type Ca2+ channels and 30% in the presence of 2.5 microM omega-conotoxin-MVIIC. These data indicate that NO inhibits both L-type and P/Q-type Ca2+ channels in RINm5F cells, probably by an increase in the intracellular levels of cGMP. NO may then significantly influence the Ca2+-dependent release of hormones from secretory cells as well as that of neurotransmitters from nerve terminals.     

Control complex of group electric drive

A control complex of a group electric drive is developed for water-pumping stations of housing and communal services that is composed of a frequency-controlled converter, four induction motors, and switching contactor equipment.     

Analysis of electromagnetic processes in the traction network under the interaction of electric locomotives in the regeneration and traction modes

An analysis of the results of simulation of electromagnetic processes in the “traction substation-catenary-electric locomotive” system with electric locomotives working in the feed zone in the traction and regenerative braking modes at different distances from the traction substation is carried out. A real-time computing complex was used for simulation. The mutual influence of electric locomotives and dispensing of active and reactive power was reviewed.     

Adsorption of hemoglobin molecules on porous silicon

It is established that hemoglobin can be immobilized in pores and on the surface of porous silicon. This is confirmed by the data of atomic force microscopy and Fourier-transform IR spectroscopy.