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Beylerian, N. M.

• Radiation Modification of Dispersed Oxides in the Region of Small Doses-I-radiation Modification of Silica

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Authors

E. A. Baklachev ¹, N. M. Beylerian ¹, H. A. Ghasarian ¹

Affiliations
1 Depurtmenr of Physical and Colloid Chemistry, Yerevan Stute University, Yerevan-375049, Munoogian st. 1, IN

Source

Journal of Surface Science and Technology, Vol 11, No 1-4 (1995), Pagination: 1-8

Abstract

Dispersed oxides, e.g. silica, when treated with penetrating radiation in the region of small doses (50-150 Gy) show maxima in physical properties (specific density, surface concentration of hydroxyl groups, adsorption ability) with raditation doses. The radiation yields (Y) of the determined physical parameters are of the order 10⁴ per 100 ev. A reorganization of the surface hydrate-hydroxylic via glass state-quartz-glass state path has been considered to occur.

Keywords

Radiation Modification, Surface Properties, Silica Modification.

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• Kinetics of the Interaction of H₂O₂ with Natural and Reclaimed Saline Soils of Ararat-plain (Armenia)

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Authors

M. Gu. Guevorkian ¹, N. M. Beylerian ¹, S. Sh. Yavrian ¹

Affiliations
1 Department of Physical und Colloid Chemistry, Yerevan State University, Yerevan-375049, A. Manoogian 1, AM

Source

Journal of Surface Science and Technology, Vol 11, No 1-4 (1995), Pagination: 9-20

Abstract

The kinetics of catalase reaction by soil profile of unreclaimned and reclaimed with different amounts of saline soils of Ararat-plain (Armenia) has been studied at the temprature interval 288-303 K and in large initial substrate concentration range. It has been established that those soils possess very low catalase activity. With the decrease of salt concentration in the upper layers of well- and semi-reclaimed saline soils, the values W_max, in Michaelis-Menten equation increase, and the activation energy of enzyme-substrate complex decay decreases. It has been assumed that the low enzymatic activity is due to unfavourable changes in colloid-chemical properties of the said soils.

Keywords

Saline Soils, Catalase Activity, H₂O₂ Enzymatic Decomposition, Enzymatic Reaction Kinetics.

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• Radiation Modification of Dispersed Oxides in the Region of Small Doses IV. Radiation Modification of Titanium Oxide

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Authors

N. M. Beylerian ¹, E. A. Baklachev ¹, H. A. Ghazarian ¹

Affiliations
1 Department of Physical and Colloid Chemistry, Yerevan State University, Yerevan-375049, A. Manoogian St. 1, AM

Source

Journal of Surface Science and Technology, Vol 12, No 1-4 (1996), Pagination: 1-8

Abstract

The modification of TiO₂, surface properties under the action of small doses (D ≃ 10₂ Gy) of γ-radiation has been studied. It has been established that the used doses are enough to stimulate polymorphic changes in the surface layers of dispersed TiO₂. In spite of the fact that the radiation energy is being absorbed by the volume of the subject, surface structure reconstruction occurs only in the narrow presuperficial layers. The changes of the properties studied (for example, the adsorption ability, crystal density, surface hydroxylic cover concentration, the ratio of acid/base centers) are due to the change of the crystal structure of the initial oxide on γ-iradiation in the region of small doses.

Keywords

Titanium Oxide, Radiation Modification, Surface Properties, Hydrated Layer Reconstruction, Action of Small Doses.

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• Surface Properties of Aqueous Solutions of Some Quaternary Ammonium Salts

Abstract Views :169  |  PDF Views:2

Authors

R. S. Haroutiounian ¹, N. M. Beylerian ¹, A. V. Babakhanian ¹

Affiliations
1 Department of Physical and Colloid Chemistry, Yerevan State University, Yerevan-375049, A. Manoogian st. 1, AM

Source

Journal of Surface Science and Technology, Vol 11, No 1-4 (1995), Pagination: 21-26

Abstract

It has been shown that the studied chlorine containing unsaturated quaternary ammonium salts (QAS) are micelle forming surfactants. Their colloid-chemical properties have been discussed on the grounds of their structural pecularities.

Keywords

Quaternary Ammonium Salts, Surfactants, Micelle-Formation, Emulsions.

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• Radiation Modification of Oxides in the Region of Small Doses. II. Radiation Modification of Aerosil as Filler for Epoxide Glues

Abstract Views :186  |  PDF Views:2

Authors

E. A. Baklachev ¹, N. M. Beylerian ¹, H. A. Ghazarian ¹

Affiliations
1 Department of Physical and Colloid Chemistry of the Yerevan State University, Yerevan-375049, Manoogian st. 1, AM

Source

Journal of Surface Science and Technology, Vol 13, No 1 (1997), Pagination: 11-17

Abstract

Some surface reactions which occur between modified under the action of small doses (D) of penetrating radiation on aerosil with polyamide and epoxy resins have been studied. Experimental data on the basis of the reconstruction of surface hydratehydroxylic cover have been discussed. It has been shown that adhesive properties of glues prepared using aerosil-type modified fillers depend on the conditions of preliminary treating of blends. The diffractographic analysis of unmodified and modified with γ-radiation (D = 100 Gy) silicon samples shows that under the action of radiation, phase transition occurs on SiO₂ crystoballite and tridimite phases are formed.

Keywords

Aerosil, Radiation Modification, Filled Composites, Phase Transition.

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• Radiation Modification of Dispersed Oxides in the Region of Small Doses. III. Radiation Modification of Zinc Oxide Surface

Abstract Views :160  |  PDF Views:2

Authors

E. A. Baklachev ¹, N. M. Beylerian ¹

Affiliations
1 Department of Physical and Colloid Chemistry of the Yerevan State University, Yerevan-375049, Manoogian st. 1, AM

Source

Journal of Surface Science and Technology, Vol 13, No 1 (1997), Pagination: 19-24

Abstract

The modification of ZnO surface properties using γ-radiation of small doses (D ∼ 10²Gy) has been studied. The adsorption of stearic acid, triethylamine, phenylglycidylether, polyamide and polyepoxide type resins, the adsorption and desorption of water molecules on modified ZnO have been investigated.

The increase of their adsorption has been discussed assuming that under the action of small doses of radiation a reconstruction of hydrated-hydroxylated cover on ZnO surface occurs.

The important role of crystalline side-specificity has been shown. The radiation changes the microstructure of each side, e.g. (0001), (0001) (1010).

Keywords

Zinc Oxide, Radiation Modification, Surface Properties, Dehydration and Dehydroxylation of Surface Layers, Crystalline Side-Specificity.

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• Phosphate Ion Influence on Phosphatase Reaction Rate in Carbonate Chernozem (Black Earth)

Abstract Views :177  |  PDF Views:1

Authors

M. G. Gevorgyan ¹, G. A. Parsadanyan ¹, N. M. Beylerian ¹

Affiliations
1 Yerevan State University, Departments of Physical and Colloid Chemistry, Ecology and Nature Conservation, Yerevan 375025, A. Manoogian St. 1, AM

Source

Journal of Surface Science and Technology, Vol 15, No 3-4 (1999), Pagination: 99-103

Abstract

It has been established that phosphate ions which are in carbonate, inhibit simultanously the formation of both Michaelis (ES) and kinetically inactive complexes (ES₂).

Keywords

Carbonate, Chernozem, Substrate Inhibition, Competitive Inhibition, Phosphate Ion.

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• γ-Radiation Modification of Magnesium Oxide

Abstract Views :322  |  PDF Views:2

Authors

E. A. Baklachev ¹, N. M. Beylerian ¹, H. A. Ghazarian ¹

Affiliations
1 Department of Physical and Colloid Chemistry, Yerevan State University, Yerevan-375049, A. Manoogian St. 1, AM

Source

Journal of Surface Science and Technology, Vol 15, No 1-2 (1999), Pagination: 69-75

Abstract

The adsorption ability, specific surface area, density changes and also the dehydration regularities of two kinds of MgO, obtained from Mg(OH)₂, under different conditions and irradiated with small doses (D) of γ-radiation, have been studied. Combining these results with the data concerning the thermo- and X-ray phase analysis, crystalochemical transformations occurring on MgO surface layers have been established. The dependence of the studied properties on D shows that in the regions D ≤ 100 - 150 Gy and D ≥ 150 Gy, different transformations occur which pre-determines the external character of property versus dose dependence. The observed changes are due to the reconstruction of surface layers by the route : brucite → periclase → brucite.

Keywords

Magnesium Oxide, Radiation Modification, Surface Properties, Small Doses Action.

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• Influence of Sodium Pentadecylsulfonate on the Rate of Diphenylamine Oxidation by Peroxidisulfate in Water-Dioxane Mixtures

Abstract Views :180  |  PDF Views:2

Authors

M. G. Gevorgyan ¹, N. M. Beylerian ¹

Affiliations
1 Yerevan State University, Department of Physical and Colloid Chemistry, Yerevan 3 75025, A. Manougian St. 1, AM

Source

Journal of Surface Science and Technology, Vol 15, No 1-2 (1999), Pagination: 90-97

Abstract

The kinetics of the reaction of Ph₂NH (A) with S₂O^2-₈ under O₂ free condition was studied in homogenous medium using H₂O+dioxane (33% by volume) solution in presence of the PDS anion active micelles. In absence of PDS micelles, Ph₂NH oxidation is consecutive, the final product being diphenylbenzidine violet. When PDS micelles are present, the over-all reaction rate decreases. At [E-30]₀ ≥ 0.16 M, the reaction is stopped at the stage of tetraphenylhydrazine (TPhH) formation, which leads to slowing down of the over-all rate of S₂O^2-₈ consumption. This fact has been explained assuming that water soluble S₂O^2-₈ and oil-soluble TPhH are localized in different loci in the reaction medium. The distribution coefficient (P_A) of the reductant between micellar and water as well as water-EtOH-dioxane solutions has been determined.

Keywords

Peroxydisulfate, Diphenylamine, Surfactant, Action of Micelles on Oxidation Rate.

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• Radiation Modification of Dispersed Oxides in the Region of Small Doses VI: Radiation Modification of Alumina

Abstract Views :174  |  PDF Views:15

Authors

E. A. Baklachev ¹, N. M. Beylerian ¹, H. A. Ghazarian ¹

Affiliations
1 Yerevan State University, Yerevan-375049, AM

Source

Journal of Surface Science and Technology, Vol 13, No 2-4 (1997), Pagination: 130-137

Abstract

The influence of irradiation in air in the region of small doses on the surface properties of alumina has been studied. Three types of alumina have been used, each of which differs from the others in density, specific surface and content of α-phase in them. On the basis of experimental data concerning the adsorption and desorption of triethylamine, stearic acid and water, X-ray phase analysis, surface acid-base centres and density changes, it has been concluded that an appreciable reconstruction of surface structure with unusually great yields, occurs at room temperatures.

Keywords

Alumina, Surface Properties, Radiation Modification.

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