Vol. 51 No. 2 (243) (2017)

The mechanism of chromate ores destruction under microwave radiation is studied by optical polarizing microscope and X-ray method. The obtained results of optical studies have been analyzed by computer simulation. It is established that under microwave radiation occurring not only local heating and mechanical splitting of chromate concentrates but also structural and chemical transformations. As a result, products of destruction are enriched with the basic substance – chromite.

The behavior of 5,5-disubstituted-3-(prop-2-ynyl)dihydrofuran-2(3H)-ones under conditions of Mannich and coupling reactions have been studied. It was established that their interaction with paraform and secondary amines in the presence of copper halogenides (I) afforded aminobutynyl derivatives of γ-lactones, and the coupling reactions with active halogenides resulted in butynalkynyl derivatives. Synthesized compounds are representatives of new systems earlier not described in the literature.

By esterification reaction of citric acid with pentadecylic, dodecylic, decyilic, and other alcohols the corresponding esters have been obtained. The effective novel methodologies of esterification reaction of citric acid at temperatures of 120–180°C with or without solvents are developed. The physical and chemical constants of the obtained compounds have been defined.

Modification of chitosan (Ch) with monomethylolurea has been carried out at diferent temperatures and macromolecules of Ch with different numbers of methylurea actionable functional groups were obtained. The kinetic parameters of the grafting of methylcarbamyl radical onto Ch macromolecules at different temperatures were studied and the rate constants and activation energies of above mentioned processes were determined.

In the article in order to study spectrophotometric measurement of thiocyanate through extraction by formation of ion pair with thionine, the partial and total order of reactions to the reactors were studied.

Interaction of intercalators: ethidium bromide (EtBr), methylene blue (MB) and acridine orange (AO), with DNA at 0.02 M ionic strength of the solution has been studied by differential spectroscopy method. It was revealed that EtBr binds to DNA by intercalation, semi-intercalation and electrostatic modes; MB by semiintercalation and electrostatic modes and AO by intercalation and electrostatic modes. It was shown that the simultaneous performance of intercalation and semiintercalation modes condition the formation of a real isosbestic point (IP) in the spectra of EtBr–DNA complexes. In the absence of intercalation at MB interaction with DNA a pseudo-IP in differential absorption spectra of those complexes is formed. In the spectra of AO–DNA complexes both IP and pseudo-IP are not formed, despite the fact that this ligand binds to DNA by intercalation mode.

The aim of the present study was to determine the contents of copper in agricultural soils situated on Darazam recultivated tailing dump and in crops growing on these soils, to evaluate the risk level of studied plants for human health and to find out their phytoremediation potential. Results of the study show that in coriander (aerial part) and in garlic (aerial and underground parts) as well as in the leaves of horseradish (fresh mass) the exceeding of maximum permissible concentration of copper content was observed. The lowest contents of copper were registered in the beans of common bean as well as in the berries of red currant and raspberry therefore these plants may be used as foodstuff. Maize has the greatest phytoremediation potential from all studied plants so it is reasonable to use this species for the reclamation of the area under the study.

The goal of this research was to explore the thermostability of active antimicrobial constituents of some Armenian herbs. The following herbs were used: Agrimonia eupatoria, Hypericum alpestre, Rumex obtusifolius and Sanguisorba officinalis. Thermal stability was determined by exploring plant extracts antimicrobial activity against Staphylococcus aureus MDC 5233 before and after heat treatment. Antimicrobial activity of the plant extracts was tested by agar well diffusion assay. Broth microdilution assay was used for determination of minimal inhibitory concentrations of the plant extracts. According to obtained data, some of the plant crude extracts retained their antimicrobial activity even after 121ºC heat exposure. In contrast, other plant extracts have lost their activity after treating just with 60ºC. Thus, obtained results about thermostability of compounds responsible for plant extracts antimicrobial activity will allow to choose appropriate temperature ranges during processing of the tested plant materials in order to maintain their antimicrobial activity.

Тhe antifungal activity (AFA) of 4 strains of Trametes gibbosa was investigated regarding potentially pathogenic for humans and animals filamentous fungi. AFA was evaluated by using 3 approaches: in mutual growing, using samples of culture liquid (CL) and mycelial extract (ME). In dual culture partial and complete overgrowth reactions on test fungi by T. gibbosa were observed. The CL and ME samples inhibited the growth rate of mycelia of test fungi up to 55.6% and 29.7%, respectively. Thus, the T. gibbosa collections, especially CL samples, possess AFA against studied filamentous fungi and are perspective for further research as a source of antimycotic compounds.

Created for the specifics of military aviation complex multiple psycho-physiological studies of individual biological characteristics of the military cadets of aptitude using a polygraph system military pilot–aircraft–environment were developed. Comprehensive psychological survey of using polygraph allows to evaluate the accuracy of the information on the adequacy of the non-specific physiological responses to verbal answers in the study and solution of problems of the human element in military aviation and prevention of dangerous flight psycho-physiological factors. Psychocorrection of functional disorders of the nervous system revealed using polygraph promotes post stress rehabilitation and maintenance of positive flight motivation of military cadets in the system of psychological security of the flight.

As a result of our research in Armenia were established 59 species of poisonous macromycetes, which belong to 16 genera, 10 families and 5 orders. The largest numbers of poisonous species are found in North-Eastern regions of the Republic. According to the data of the Ministry of Healthcare of RA, in 2014–2016 on the entire territory of the Republic were registered 147 poisoning cases with fungi.

During 2013–2015 the foliage population of trees from different sides with ordinary pear psylla was studied. At the same time based on estimation the population of various parts of trees with this phytophagous has been identified. It was found out that in considerably shadow, poorly illuminated parts (north and west) of pear habitus, the population of plants with psylla has been lower than in eastern and northern parts. Therefore, in the process of undertaking chemical control is important to spray intensively the lower level of pear leaves with working solution.