Vol. 41 No. 3 (214) (2007)

By gasometric method the influence of vitamin C on the catalized by Fe(II) cations rate of H₂O₂ decomposition has been studied at 298 K. In the range pH=2–4 and n = [H₂O₂ ]₀ / [Fe(II)]₀ $\gg$1 the reaction rate ( $R^0_{\mathrm {O}_2}$ ) does not depend on the medium’s acidity. But at pH>4 the increase of pH value results in $R^0_{O_2}$ decrease, which is due to the catalyzing hydrolysis. The rate law is $R^0_{\mathrm {O}_2} = k\dfrac{[\mathrm{H}_2\mathrm{O}_2 ]_0 [\mathrm{Fe(II)}]_0}{a+[\mathrm{H}_2\mathrm{O}_2 ]_0}$. This law is discussed. In the presence of low quantities of vitamin C, e.g. 1.25· 10^-3 M, the rate diminishes 3 times. When TEMPO is present with vitamin C (~10^-4 M) the O₂ evolution rate somewhat increases. Both phenomenas are explained. On the ground of analysis of obtained kinetic data it is assumed that the studied reaction probably occurs parallel by radical and nonradical mechanisms.

The electrochemical and corrosive properties of zinc-lead anodic alloy obtained by high-speed melt-hardening method with application of direct current has been investigated in this paper. This alloy permits to apply for anodes of dry alkaline batteries.

A sorbent based on medioporous industrial silica by precipitated carbonizate of saccharose on it`s surface was obtained. It was shown, that obtained sorbents differ from the initial sorbents in structure of porositi, and in hidrophiliti of the surface. It has been found out, that hidrophile-hidrophob balance of its surface can be regulated by treatment of this sorbent with gas products of chemical transport reaction (CTR) ZnO/H₂O₂.

In this work the possibility of malachite reduction under the combustion mode was studied using solid combined reducers of C–N–O–H type. Combustion and structure formation laws were revealed depending on different factors. It was established that controlling the conditions of reduction process it is possible to obtain copper with porosity up to 90%.

The interaction of cupric chloride anionic complex with threephenilmethane basic dye Brilliant Green has been studied. The colored ionic associate could be extracted by benzole in 0.5–1.0 N sulphuric acid solutions. The method is based on the reduction of copper (II) to copper (I) with ascorbic acid.The calibration graph obeyed Beer’s law over the range 0.2–6.25 mcg/mL copper and the apparent molar absorptivity of the extract at 625 nm was (82300 ± 700)L·mol^-1·сm^-1. The molar ratio between copper (I) chloride complex and Brilliant Green in ionic associate has been determined by Asmus straight line and shifts on equilibrium methods which 1:1. The influence of interfering elements on the determination of copper is used in natural and waste waters. The proposed method is very sensitive than those reported earlier.

The derivatives of 6-bromo- and 8-chloro-4-(hydroxyphenilamino) and        4-(aminophenylamino)-2-methylquinolines are obtained by interaction of 2-methyl- 4-chloroquinolines with o-, m-, p-aminophenoles and o-, m-, p-phenylendiamines.

Research of interaction of Hoechst 33258 with DNA, binding through a minor groove of DNA, by spectroscopic (fluorescent and absorption) methods is carried out. It is revealed, that this ligand with DNA binds by two modes – strong and weak. The strong type of interaction Hoechst 33258 with DNA is detected by both fluorescent and absorption methods, while the weak type is observed only by the absorption method. On the basis of the analysis of the spectroscopic data values of parameters of linkage - K and n are calculated.

The cytogenetic influence of water samples in river Hrazdan (on the territory of Yerevan) in test-object Allium cepa was investigated. 6 points for the collection of water samples were selected. Time and space heterogenicity of clastogenic activity is revealed caused by municipal and technogenic load of Hrazdan river.

17 karstic caves of Armenia and 8 caves of Nagorno Karabach are investigated. Brief representation of design of caves, history of their formation and also their biodiversity, in particular structure of their flora and fauna is given.

The list of 30 species of Hyphales is given, which supplements the list of species included in the third volume of «Mycoflora of the Armenian SSR» (1975).

In this paper there are keys for definition of species belonging of Amphibians' eggs, tadpoles and adult specimen in Armenia.