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Sergey S. Hayrapetyan, Martin S. Hayrapetyan, Armen I. Martiryan, Hranoush H. Darbinyan, Hambardzum H. Khachatryan
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 125-135; https://doi.org/10.46991/pysu:b/2021.55.2.125

Abstract:
The sorption properties of organomineral composite sorbents have been investigated by ICP-MS method. The diatomite of the Jradzor deposit and bentonite of the Sarigyuh deposit (Armenia) were used as inorganic constituents. Diatomite serves as a structure-forming component and provides mass transfer due to its high porosity (V = 2.0 cm3/g) and large pore sizes (150–200 nm). Bentonite is responsible for the functionality of the sorbents. The organic component is also responsible for the functionality of the obtained sorbents. Paper pretreated with acids (nitric and phosphoric) was used as an organic component. A synthetic solution containing cations of heavy metals was used as an object of study. The experiments were carried out in static mode on a Jar-Test device.
Marine A. Parsadanyan, Mariam A. Shahinyan, Zvart H. Movsisyan, Ara P. Antonyan
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 144-150; https://doi.org/10.46991/pysu:b/2021.55.2.144

Abstract:
Study on the interaction of DNA-specific ligands – classical intercalator acridine orange (AO) and groove binding compound Hoechst 33258 (H33258) with poly(rA)-poly(rU), being a model for double-stranded (ds-) RNA, has been carried out. The absorption and fluorescence spectra of the complexes of these ligands with ds-polynucleotide were obtained. It was revealed that the optic and fluorescent characteristics of the complexes of both ligands with ds-RNA are similar with those at the complex-formation with DNA.
Tariel V. Ghochikyan, Armen S. Galstyan, Hrachik M. Stepanyan, Irina G. Korpakova, Alexander S. Kinzirsky
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 103-111; https://doi.org/10.46991/pysu:b/2021.55.2.103

Abstract:
Based on carbonyl derivatives of 4-substituted-4-butanolides, the appropriate semi- and thiosemicarbazones have been synthesized. It has been found that some representatives of thiosemicarbazones have pronounced algicidal activity against filamentous green alga Cladophora and blue-green alga (cyanobacterium) Synechocystis and some of the semi- and thiosemicarbazones exhibit moderate antitumor activity. The assessment of the antitumor activity of the compounds was carried out using strains of syngeneic and allogeneic tumor systems as test-objects: lymphocytic leukemia P-388, Lewis lung carcinoma, B16 melanoma and Ehrlich’s ascites tumor. It has also been established that some representatives of thiosemi­carbazones exhibit antimutagenic properties. It has been reliably proven that with the formation of a thiazole ring, all properties disappear and a new property in the series of thiazololactones is revealed – antibacterial․
Mariam A. Shahinyan, Zvart H. Movsisyan, Gohar G. Hovhannisyan, Poghos H. Vardevanyan
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 151-157; https://doi.org/10.46991/pysu:b/2021.55.2.151

Abstract:
The interaction of methylene blue (MB) and acridine orange (AO) with poly(rA)-poly(rU) was studied using absorption and fluorescence spectroscopy methods. The absorption and fluorescence spectra of complexes of these ligands with a polynucleotide were obtained, similar to those of complexes of these ligands with double-stranded (ds-) DNA. It was revealed that the isosbestic point in the spectra of the AO-poly(rA)-poly(rU) and MB-poly(rA)-poly(rU) complexes is not formed, although the binding of AO and MB with ds-RNA by intercalation mode is not excluded.
Karine R. Grigoryan, Hasmik A. Shilajyan, Iskuhi L. Aleksanyan, Zara L. Grigoryan, Lilit P. Hambardzumyan
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 112-117; https://doi.org/10.46991/pysu:b/2021.55.2.112

Abstract:
Fluorescence properties of 4-hydroxy-2-methylquinoline (1) and 2-(5-mercapto-1,3,4-oxadiazol-2-yl)-6-methylquinoline-4-ol (2) were studied in dimethylsulfoxide (DMSO) aqueous solutions. The fluorescence properties of 1 and 2 exhibit substantial dependence on the DMSO concentration. The fluorescence quantum yield $(\Phi_f)$ of 1 decreases upon adding DMSO due to the shift in the keto-enol (E) tautomeric equilibrium toward E form․ On the contrary 2 demonstrates a tendency of increase of $\Phi_f$ upon adding DMSO due to intermolecular charge transfer from DMSO to the aromatic ring of quinoline, which increases the electron density on the ring and hence the fluorescence efficiency.
Lyudmila G. Niazyan
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 181-188; https://doi.org/10.46991/pysu:b/2021.55.2.181

Abstract:
West Nile Disease (WND) is an emerging infectious vector borne disease. Of registered invasive species of mosquitoes in Armenia, Culex pipiens is the most implicated one in the potential transmission of WNV. In previous years (1985–1999), research on circulation of mosquito-borne arboviruses in Armenia was conducted by the research Institute of Epidemiology and WNV, Batai, Sindbis, Tahyna and Gheta were found in mosquitoes. The only mosquito-borne disease historically registered in Armenia was malaria, without autochtonous cases since 2006. However, per retrospective medical chart review study (2016–2019) in the Nork Infection Clinical Hospital, about 30% of febrile patients is diagnosed as “Fever of Unknown Origin”. We hypothesize that these arboviruses are circulating in Armenia and largely mis-diagnosed and/or under reported. Based on the geographical locations of mosquitoes, the MaxEnt model with 19 bioclimatic variables was developed to predict future ecological niche of C. pipiens and potential high-risk areas for WND. It is the first step for the implementation of a statistically rigorous system for real-time alert of biorisk.
Samvel H. Jilavyan, Asatur Zh. Khurshudyan
Proceedings of the YSU A: Physical and Mathematical Sciences, Volume 55, pp 123-130; https://doi.org/10.46991/pysu:a/2021.55.2.123

Abstract:
The concept of averaged controllability has been introduced relatively recently aiming to analyse the controllability of systems or processes containing some important parameters that may affect the controllability in usual sense. The averaged controllability of various specific and abstract equations has been studied so far. Relatively little attention has been paid to averaged controllability of coupled systems. The averaged state of a thermoelastic rectangular plate is studied in this paper using the well-known Green's function approach. The aim of the paper is to provide a theoretical background for further exact and approximate controllability analysis of fully coupled thermoelasticity equations which will appear elsewhere.
Nara H. Petrosyan
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 158-164; https://doi.org/10.46991/pysu:b/2021.55.2.158

Abstract:
The study on the interaction of DNA-specific low-molecular compounds – groove binding material Hoechst 33258 and intercalating ligand methylene blue (MB) with serum albumin has been carried out. The absorption and differential absorption spectra of complexes of the mentioned ligands with protein were obtained. Changes of the absorption and differential absorption spectra indicate the binding of two ligands with albumin. The obtained results indicate that at the interaction with both ligands, the conformational state of the protein alters, though these changes are not similar, since in the case of MB a compactization of the protein folding occurs, while in the case of Hoechst 33258, most apparently, an unfolding of the compact structure takes place as a result of partial loss of helicity of $\alpha$-structures.
Poghos H. Vardevanyan, Mariam A. Shahinyan, Anna V. Vardanyan, Svetlana V. Grigoryan
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 136-143; https://doi.org/10.46991/pysu:b/2021.55.2.136

Abstract:
In this work the effect of millimeter range electromagnetic waves (MM EMW) with the frequency 64.5 GHz on the complexes of Hoechst 33258 (H33258) with DNA and human serum albumin (HSA) has been studied by the methods of absorption and fluorescence spectroscopies. It was shown that the irradiation results in weakening of H33258 interaction with both macromolecules, which is connected with the fact that the frequency 64.5 GHz, being resonant for water, leads to the structurizing of water component around DNA and HSA, due to which the binding becomes weaker. This conclusion is based on the values of both binding constants and Stern–Volmer constants.
Hranoush H. Darbinyan, Hambardzum H. Khachatryan
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 196-198; https://doi.org/10.46991/pysu:b/2021.55.2.196

Abstract:
The content of selenium organic forms in Astragalus and Thyme officinal plants was determined by means of spectrophotometry method using phenylthiourea as a reagent. The selenium content estimated spectrophotometrically is equal to: 11750 μg/kg in Astragalus and 450 μg/kg in Thyme. The amount of selenium in these plants determined earlier by means of mass-spectrometry method is equal to 12000 μg/kg and 600 μg/kg, respectively.
Siranush M. Minasyan, Emma S. Gevorkyan, Tsovinar I. Adamyan, Susanna H. Sargsyan, Lilit E. Ghukasyan
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 189-195; https://doi.org/10.46991/pysu:b/2021.55.2.189

Abstract:
The results of the study have shown that when exposed to vibration, changes in cardiac activity occur in rabbits, the nature and direction of which depend on the parameters of the dynamic factor. Vibration with a frequency of 20 Hz causes moderate tachycardia, and 40 and 80 Hz – severe tachycardia. Three months of vibration in the first month of exposure causes tachycardia, and after three months of exposure, bradycardia. There is also a reduction in respiratory movements and a decrease in the activity of the enzyme succinate dehydrogenase.
Ashot A. Matevosyan, Aram G. Matevosyan
Proceedings of the YSU A: Physical and Mathematical Sciences, Volume 55, pp 131-140; https://doi.org/10.46991/pysu:a/2021.55.2.131

Abstract:
Simple harmonic motion was investigated of a rotational oscillating system. The effect of dumping and forcing on motion of the system was examined and measurements were taken. Resonance in a oscillating system was investigated and quality factor of the dumping system was measured at different damping forces using three different methods. Resonance curves were constructed at two different damping forces. A probabilistic model was built and system parameters were estimated from the resonance curves using Stan sampling platform. The quality factor of the oscillating system when the additional dumping was turned off was estimated to be $Q = \num{71 \pm 1}$ and natural frequency $\omega_0 = \num{3.105 \pm 0.008}\, \si{\per\second}$.
Davit A. Martiryan
Proceedings of the YSU A: Physical and Mathematical Sciences, Volume 55, pp 141-147; https://doi.org/10.46991/pysu:a/2021.55.2.141

Abstract:
The use of the method developed in the CLAS collaboration (Jefferson Lab, USA) of improving leptons momentum for more correct studies of final state selection of quasi-real photoproduction resulting from the reaction to near threshold photoproduction of the $J/\psi$ meson is described. The radiation photons that were detected in electromagnetic calorimeter were studied with electrons and positrons accompanied them in very narrow angles. The method of radiated photon selection of $e^+ e^- p^{\prime}(e^{\prime})$ reaction is given, where $e^+ e^-$ lepton pair is formed during the decay of $J/\psi$ meson.
Karen K. Grigoryan
Proceedings of the YSU A: Physical and Mathematical Sciences, Volume 55, pp 148-152; https://doi.org/10.46991/pysu:a/2021.55.2.148

Abstract:
In the context of the Abraham–Minkowski controversy, the problem of the propagation of electromagnetic waves in a linear dielectric medium with a time-varying dielectric constant is considered. It is shown that the momentum of an electromagnetic wave in the form of Minkowski is preserved with an instantaneous change in the dielectric permittivity of the medium. At the same time, the Abraham momentum is not conserved, despite the spatial homogeneity of the problem. This circumstance is interpreted as a manifestation of the Abraham force.
Gevorg S. Grigoryan
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 118-124; https://doi.org/10.46991/pysu:b/2021.55.1.118

Abstract:
The formation of Ni2+:Tryptophan (Trp) 1:1 complex, which acts as a model catalyst for decomposition of cumene hydroperoxide (ROOH) in Ni2++Trp+ROOH+H2O system, has been confirmed via kinetic study in aqueous solution at pH>7. The kinetic expression of a single catalytic decomposition reaction of ROOH under the influence of [NiTrp]+ complex was brought out. The temperature dependence of the effective rate constant of ROOH decay (Keff=Kcat[Ni2+]0[Trp]0=const) in the temperature range from 323 to 343 K can be expressed by Arrhenius equation (Eeff is in kJ/mol): Keff=(1.87±0.02)·106exp[–(49.8±0.3)/RT], min –1.
Liya A. Minasbekyan, Inesa A. Avagyan
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 165-171; https://doi.org/10.46991/pysu:b/2021.55.2.165

Abstract:
The study of the effect of different doses of $\gamma$-irradiation on the growth and development of seedlings of soft wheat seeds, resistance, and germination of seeds to irradiation has been carried out. The data show that the seeds of common wheat are resistant to ionizing radiation and up to 80% of the seeds remained viable. Under the influence of ionizing radiation, the functional and mitotic activity of the cell nucleus is disrupted, which has a significant effect on the growth parameters of the seedlings of irradiated seeds.
Iren V. Shahazizyan, Inessa M. Eloyan, Ruzanna E. Matevosyan, Siranoush G. Nanagyulyan
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 172-180; https://doi.org/10.46991/pysu:b/2021.55.2.172

Abstract:
In this work we studied the effect of microscopic soil fungi on some lather samples. The species composition of micromycetes inhabiting the samples under study was revealed, and an assessment of the fungal resistance of the materials under study was given. In the process of work, species of microscopic soil fungi were isolated and identified from the soil. In order to determine the degree of resistance to fungi for the infection of samples, a water-spore suspension was obtained. The leather materials were partially destroyed by microscopic fungi, and mold resistance ranged from 2 to 3 on a 5-point scale.
Aram H. Gharibyan, Petros A. Petrosyan
Proceedings of the YSU A: Physical and Mathematical Sciences, Volume 55, pp 96-112; https://doi.org/10.46991/pysu:a/2021.55.2.096

Abstract:
In this paper we generalize locally-balanced $2$-partitions of graphs and introduce a new notion, the locally-balanced $k$-partitions of graphs, defined as follows: a $k$-partition of a graph $G$ is a surjection $f:V(G)\rightarrow \{0,1,\ldots,k-1\}$. A $k$-partition ($k\geq 2$) $f$ of a graph $G$ is a locally-balanced with an open neighborhood, if for every $v\in V(G)$ and any $0\leq i
Albert Kh. Sahakyan, Rafayel R. Kamalian
Proceedings of the YSU A: Physical and Mathematical Sciences, Volume 55, pp 113-122; https://doi.org/10.46991/pysu:a/2021.55.2.113

Abstract:
An edge-coloring of a graph $G$ with consecutive integers $c_1,\ldots,c_t$ is called an interval t-coloring, if all colors are used, and the colors of edges incident to any vertex of $G$ are distinct and form an interval of integers. A graph $G$ is interval colorable, if it has an interval t-coloring for some positive integer $t$. In this paper, we consider the case, where there are restrictions on the edges of the tree and provide a polynomial algorithm for checking interval colorability that satisfies those restrictions.
Eleonora Natalia Ravizza
Armenian Folia Anglistika, Volume 17, pp 108-123; https://doi.org/10.46991/afa/2021.17.1.108

Abstract:
First published in 1918, Rebecca West’s debut novel The Return of the Soldier focuses on a common trope in Great War Literature: the traumas of war and the difficulties of returning veterans to fit back in with everyday life. The story of the shell-shocked soldier Chris Baldry, who suddenly finds himself in a world which has aged 15 years beyond his memory, may be read as the unfolding of a multi-layered drama of hospitality, in which the host-guest continuum is constantly renegotiated. Chris’s memory erasure does not only turn him into a foreigner who does not recognize his wife or remember his dead son, but also forces his family members to question the role they have been playing in Chris’s life. His family equilibrium is shattered as his wife suddenly becomes a stranger to him, while his long-lost love, a working-class woman well below Chris’s social standards, become more important to him than anyone else. An analysis of the modernist techniques and stylistic features of the novel will allow me to address the concept of hospitality in relation to trauma and disease. The paper will show that The Return of the Soldier may be read not only as a critique of war, but also as a multi-perspective narrative on the precariousness of host-guest relationships. It will be argued that the “question-of-the-foreigner”, which Derrida addressed in his seminal essay Of Hospitality (2003) acquires new meanings when disease suddenly transforms a loved one into an “other” with whom communication seems to be interrupted. Hospitality may thus be regarded an unstable concept, in which identity and alterity are constantly renegotiated.
Iryna Shevchenko
Armenian Folia Anglistika, Volume 17, pp 24-34; https://doi.org/10.46991/afa/2021.17.1.024

Abstract:
This article explores the role of metaphor in the conceptualization of economic crisis in English in terms of the sociohistorical – cognitive – linguistic interface. On the material of economic mass-media discourse of the 19th century “long depression”, the 20th century Great Depression and the 21st century Global Economic Crisis It reveals the concept historical variation and defines the vector of its development. It also develops the methodology of historical cognitive analysis and proves that being а part of human social-cultural practice cognition is of historical nature. I claim that in historical perspective conceptual metaphors vary in their source domains as the result of transformations of the concept structure. The vector of diachronic change of conceptual metaphors of economic crisis corresponds to cladogenesis, which is the process of evolutionary splitting based on branching.
Angela Locatelli
Armenian Folia Anglistika, Volume 17, pp 96-107; https://doi.org/10.46991/afa/2021.17.1.096

Abstract:
The aim of this essay is to propose a view of literary translation as “performance”, i.e., as both an art and an activity endowed with specific affinities with those of the actor or the musician. Actors and musicians offer subjective interpretations of the dramatic texts and of the musical scripts that they present on stage and in the concert hall. Likewise, the translator presents her/his interpretation and her/his rendering of a specific text to readers whose mother tongue and culture may either be close or remote from the ones of the original. In other words, a translator of artistic literature is ‘a performer’ and each translation an ‘execution’ i.e., a unique ‘rendering of the script’ (T1), and it is both a recognizable prior text (T1) and yet also a specific variation of it (T2). After some theoretical observations on translation (Part 1 of the essay), my thesis will be developed in connection with an interpretation of the character of Bottom, the weaver-actor in A Midsummer Night’s Dream, because his experience and ‘personality’, seem to bear interesting metaphorical affinities with those of the translator as performer of poetic texts (Part2 of the essay).
Yelena Yerznkyan, Grisha Gasparyan
Armenian Folia Anglistika, Volume 17, pp 9-23; https://doi.org/10.46991/afa/2021.17.1.009

Abstract:
The article touches upon graffiti discourse as a form of rhetorical speech and tries to analyse it according to the three strategies of persuasion suggested by Aristotle: ethos, pathos and logos. The article reveals how specific the graffiti discourse is in terms of using these strategies and how the latter make the speech more powerful and persuasive. Also, an attempt is made to reveal the role of metaphor in the performance of the strategy of pathos in graffiti discourse.
Gaiane Muradian
Armenian Folia Anglistika, Volume 17, pp 85-95; https://doi.org/10.46991/afa/2021.17.1.085

Abstract:
Communication is a social phenomenon based on sharing information, ideas and attitudes. Maturity, experience, personal and social relationships that run more smoothly and become more meaningful, are developed, expanded and advanced through communication. Hence, the purpose of this paper based on case study methodology is to help students understand the principles of communication theory/study and put them into practice in life. The skills and techniques learned in the course are essential to effective communication in intrapersonal, interpersonal, small-group and public speaking and can be applied not only through studying the theoretical material but also through practical exercises, discussions and presentations that will enable to incorporate them into daily life and activity. As a result, students will learn to function in a more productive and assertive way in public and work environments and develop the newfound abilities to speak up effectively in other contexts.
Lilith Ayvazyan
Armenian Folia Anglistika, Volume 17, pp 124-149; https://doi.org/10.46991/afa/2021.17.1.124

Abstract:
The Victorian poet Algernon Charles Swinburne (1837-1909) is famous for his uniquely “bizarre” female characters. His contemporary critics as well as many of the researchers who touched upon his work have interpreted his female characters to be “obsessive,” “masochistic,” and in some cases even “sadistic.” Phædra is one of his characters who suffered the most because of this misconception. Rarely referenced at all, she has been regarded as a one-dimensional “masochist” who lacks psychological and emotional depth and whose only driving force is her desire for death. However, a close reading of Swinburne’s short poem reveals Phædra’s innermost anxieties and places her in the narrative of the Swinburnian femme damnée inspired by Les Fleurs du Mal of the French poet Charles Baudelaire (1821-1867). Swinburne’s “Phædra” is remarkable in that it also serves as an exceptional representation of Sappho (c. 630 - c. 570 BC) in Victorian England. This paper highlights Swinburne’s aversion towards the Victorian mock-morality, as well as some of his life-long influences. Furthermore, this paper defines Phædra in a new light by considering the classical originals, Sappho’s and Baudelaire’s works, and even a twentieth-century retelling by the Russian poetess Marina Tsvetaeva (1892-1941).
Hamlet Arakelyan
Armenian Folia Anglistika, Volume 17, pp 73-84; https://doi.org/10.46991/afa/2021.17.1.073

Abstract:
The language of advertising is unique and very peculiar in comparison with other elements of media discourse. The effectiveness of speech in advertising media discourse focuses on catching the attention of the target audience. Since the language of advertising is characterized by a distinguished persuasive function, the creators of ads spare no effort to make them catchy, interesting and witty. This is the reason why various linguistic devices are used to facilitate the comprehension and memorization of advertisements. In this regard, wordplay plays a significant role as the intentional usage of puns ensures the effectiveness of the composed texts.
Alina Petrosyan
Armenian Folia Anglistika, Volume 17, pp 35-51; https://doi.org/10.46991/afa/2021.17.1.035

Abstract:
Medicine contributes to every person’s health in terms of diagnosis, treatment or prevention of a disease. Hence, constructing the clinical picture and the diagnosis of a health condition and conveying complex technical information in a comprehensible language is of utmost importance. In this regard, medical professionals rely not only on Greco-Latin terms of Classical times, but also resort to metaphors to illuminate many facets of medical observations and clinical findings. These metaphors stem either from anthropomorphic or zoomorphic areas and act as primary interface between scientific thought and understanding. From this perspective, the present article examines the value of metaphor in medicine and through the employment of descriptive method, explores some of the most widespread zoomorphic metaphors, which denominate certain facial anomalies.
Rafayel Harutyunyan
Armenian Folia Anglistika, Volume 17, pp 52-62; https://doi.org/10.46991/afa/2021.17.1.052

Abstract:
The article considers political discourse as a global unit attaching special significance to its linguistic characteristics that play an essential role in the formulation of political speech. The article reviews the theoretical background of the basic approaches and theories studying political speech and tries to outline their role in the context of the critical analysis of political discourse. The article also touches upon the main components of politics: language, action, conflict and cooperation, etc.
Ofelya Poghosyan, Varduhi Ghumashyan
Armenian Folia Anglistika, Volume 17, pp 63-72; https://doi.org/10.46991/afa/2021.17.1.063

Abstract:
Political discourse carried out with powerful linguistic and extralinguistic means is utterly linked with the usage of antonomasia. In fact, it is the language of politicians used as a tool to manipulate the audience. Political speech is not necessarily a success because of its correctness or truth, rather it may be a matter of persuading valid arguments. Political discourse as a teaching and persuasive, impressive and effective speech is one of the means to give solutions to the most important problems of constructing optimal speech interchange varying from political negotiations to orations and appeals (including the ones in the mass media). It is a well-known fact that the audience of politicians is very large, and their aim is to make the audience believe or agree with them, accept their viewpoints or at least share their approaches to the solutions of these or those problems. In this regard the role of proper utilization of antonomasia in political discourse becomes of utmost importance as it presupposes the realization of a particular language function in terms of the politician’s intention to send the necessary information to his audience, either readers or listeners. In the scope of the present article we focus on the study of the functions of antonomasia in political discourse and apply the methods of observation, discourse analysis, as well as the descriptive and explanatory methods. Hence, in political discourse stylistic devices are frequently used by politicians to carry out this or that particular purpose of utterance and in this connection the usage of antonomasia is not an exception.
Rachid Boukoucha
Proceedings of the YSU A: Physical and Mathematical Sciences, Volume 55, pp 1-11; https://doi.org/10.46991/pysu:a/2021.55.1.01

Abstract:
In this paper we characterize the integrability and the non-existence of limit cycles of Kolmogorov systems of the form \begin{equation*} \left\{ \begin{array}{l} x^{\prime }=x\left( R\left( x,y\right) \exp \left( \dfrac{A\left( x,y\right) }{B\left( x,y\right) }\right) +P\left( x,y\right) \exp \left( \dfrac{C\left( x,y\right) }{D\left( x,y\right) }\right) \right) , \\ \\ y^{\prime }=y\left( R\left( x,y\right) \exp \left( \dfrac{A\left( x,y\right) }{B\left( x,y\right) }\right) +Q\left( x,y\right) \exp \left( \dfrac{V\left( x,y\right) }{W\left( x,y\right) }\right) \right) , \end{array} \right. \end{equation*} where $A\left( x,y\right)$, $B\left( x,y\right)$, $C\left( x,y\right)$, $D\left( x,y\right)$, $P\left( x,y\right)$, $Q\left( x,y\right)$, $R\left(x,y\right)$, $V\left( x,y\right)$, $W\left( x,y\right)$ are homogeneous polynomials of degree $a$, $a$, $b$, $b$, $n$, $n$, $m$, $c$, $c$, respectively. Concrete example exhibiting the applicability of our result is introduced.
Feliks V. Hayrapetyan
Proceedings of the YSU A: Physical and Mathematical Sciences, Volume 55, pp 20-28; https://doi.org/10.46991/pysu:a/2021.55.1.020

Abstract:
In the paper an equation $\partial g(z)/\partial \overline{z} = v(z)$ is considered in the unit disc $\mathbb{D}$. For $C^k$-functions $v$ $(k = 1,2,3,\dots, \infty)$ from weighted $L^p$-classes $(1 \leq p < \infty)$ with weight functions of the type $|z|^{2\gamma} (1-|z|^{2\rho})^{\alpha}$, $z \in \mathbb{D}$, a family $g_{\beta}$ of solutions is constructed ($\beta$ is a complex parameter).
Gagik K. Vardanyan
Proceedings of the YSU A: Physical and Mathematical Sciences, Volume 55, pp 44-55; https://doi.org/10.46991/pysu:a/2021.55.1.044

Abstract:
An $n$-poised node set $\mathcal X$ in the plane is called $GC_n$ set, if the fundamental polynomial of each node is a product of linear factors. A line is called $k$-node line, if it passes through exactly $k$-nodes of $\mathcal X.$ At most $n+1$ nodes can be collinear in $\Xset$ and an $(n+1)$-node line is called maximal line. The well-known conjecture of M. Gasca and J.I. Maeztu states that every $GC_n$ set has a maximal line. Until now the conjecture has been proved only for the cases $n \le 5.$ In this paper we prove some results concerning $n$-node lines, assuming that the Gasca--Maeztu conjecture is true.
Khachik S. Smbatyan
Proceedings of the YSU A: Physical and Mathematical Sciences, Volume 55, pp 36-43; https://doi.org/10.46991/pysu:a/2021.55.1.036

Abstract:
Given a proper edge coloring $\alpha$ of a graph $G$, we define the palette $S_G(v,\alpha)$ of a vertex $v\in V(G)$ as the set of all colors appearing on edges incident with $v$. The palette index $\check{s}(G)$ of $G$ is the minimum number of distinct palettes occurring in a proper edge coloring of $G$. A graph $G$ is called nearly bipartite if there exists $ v\in V(G)$ so that $G-v$ is a bipartite graph. In this paper, we give an upper bound on the palette index of a nearly bipartite graph $G$ by using the decomposition of $G$ into cycles. We also provide an upper bound on the palette index of Cartesian products of graphs. In particular, we show that for any graphs $G$ and $H$, $\check{s}(G\square H)\leq \check{s}(G)\check{s}(H)$.
Tigran M. Grigoryan, Artavazd A. Maranjyan
Proceedings of the YSU A: Physical and Mathematical Sciences, Volume 55, pp 12-19; https://doi.org/10.46991/pysu:a/2021.55.1.012

Abstract:
In this paper we proved that the Faber--Schauder functions form an unconditional representation system for $L^1$.
Seyran P. Stepanyan
Proceedings of the YSU A: Physical and Mathematical Sciences, Volume 55, pp 64-71; https://doi.org/10.46991/pysu:a/2021.55.1.064

Abstract:
In this paper, based on the refined theory of orthotropic plates of variable thickness, a system of differential equations is obtained for solving the problem of bending of an elastically restrained beam with an intermediate condition. The beam thickness is constant and is subject to a uniformly distributed load. The effects of transverse shear are also taken into account. Passing to dimensionless quantities, an analytical closed solution is obtained. The question of the influence of changing the place of application of the intermediate condition on the solution is discussed. Depending on the location of the hinge bearing, the question of optimality was posed and resolved according to the principle of minimum maximum deflection. The results are presented in both tabular and graphical form. Based on the results obtained, appropriate conclusions are drawn.
Tigran A. Grigoryan, Murad S. Hayrapetyan
Proceedings of the YSU A: Physical and Mathematical Sciences, Volume 55, pp 72-80; https://doi.org/10.46991/pysu:a/2021.55.1.072

Abstract:
In this paper several problems related to the implementation of the method for the approximate calculation of distance between regular events for multitape finite automata are considered and resolved. An algorithm of matching for the considered regular expressions is suggested and results of the algorithm application to some specific regular expressions are adduced. The proposed method can be used not only for the mentioned implementation, but also separately.
Arman S. Shahinyan
Proceedings of the YSU A: Physical and Mathematical Sciences, Volume 55, pp 56-63; https://doi.org/10.46991/pysu:a/2021.55.1.056

Abstract:
The linearized dynamics of a UAV is considered along with a pendulum hanging from it. The state trajectories of the center of mass of the UAV are given. Given the trajectory of the center of mass of the UAV and the state trajectory of its yaw angle, we have to find the control actions and conditions under which the UAV would follow the path while holding the pendulum stable around its lower equilibrium point. The problem is solved using the method for solving inverse problems of dynamics. All the state trajectories of the system and all the control actions are calculated. The condition is obtained under which a solution to the path following problem exists. A specified simple trajectory is chosen as an example for visualizing the results.
Artur A. Hoghmrtsyan
Proceedings of the YSU A: Physical and Mathematical Sciences, Volume 55, pp 90-95; https://doi.org/10.46991/pysu:a/2021.55.1.090

Abstract:
In this article, we present energy resolution studies of an electromagnetic calorimeter prototype for Electron–Ion Collider. The results of energy resolution for various configurations of lead tungstate crystals were obtained based on the Geant4 simulation package. The energy resolution was studied as a function of the polar angle of incident electrons in a momentum range of 1 to 10 GeV.
Vazgen S. Gevorgyan
Proceedings of the YSU A: Physical and Mathematical Sciences, Volume 55, pp 81-89; https://doi.org/10.46991/pysu:a/2021.55.1.81

Abstract:
In modern integrated circuits, the channel length of the transistors is reduced, and the supply voltages are also reduced. But the threshold voltages of the transistors cannot be reduced so quickly due to the physical properties of the materials used, which decreases the operating range of the transistors and makes noises comparable to them. Therefore, it is necessary to eliminate the influence of noise sources in the circuits, in particular, reflections between the transmission line and the output of the transmitter. A system is proposed for calibrating the output impedance of the transmitter based on an accurate external resistor with comparator unit offset voltage compensation. Existing analog and reference frequency based solutions have key disadvantages such as the inability to compensate the offset voltage after the integrated circuit is fabricated, and the distribution of the calibration voltage across the Input/Output device and constant power consumption during the operation. The proposed circuit includes a high-precision digital-to-analog converter to compensate the comparator offset voltage. It generates calibration codes for the pull-up and pull-down parts of the transmitter output buffer, and provides fine tuning of the output impedance. The circuit was modeled using 16 nm FinFET process elements and simulated with HSPICE simulator.
Hovhannes Z. Zohrabyan, Victor K. Ohanyan
Proceedings of the YSU A: Physical and Mathematical Sciences, Volume 55, pp 29-35; https://doi.org/10.46991/pysu:a/2021.55.1.029

Abstract:
In this paper, we showed that it is possible to use gradient descent method to get minimal error values of loss functions close to their Bayesian estimators. We calculated Bayesian estimators mathematically for different loss functions and tested them using gradient descent algorithm. This algorithm, working on Normal and Poisson distributions showed that it is possible to find minimal error values without having Bayesian estimators. Using Python, we tested the theory on loss functions with known Bayesian estimators as well as another loss functions, getting results proving the theory.
Valentina M. Mavisakalyan, Mejlum L. Yeritsyan
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 7-11; https://doi.org/10.46991/pysu:b/2021.55.1.007

Abstract:
By the interaction between N-methylolthiourea and Co2+, Mn2+ acetates are obtained compounds that were later used for the synthesis of vinyl bifunctional groups containing polymerizable chelate complexes. These compounds are recommended to be used as crosslinkers for obtaining, on the basis of water-based soluble monomers, spatially cross-linked water-swellable copolymers with applied purpose. There are dynamics of water absorption of copolymers from the time of their stay in water.
Heghine Kh. Gevorgyan, Anait V. Vassilian, Karen A. Trchounian
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 67-74; https://doi.org/10.46991/pysu:b/2021.55.1.067

Abstract:
This research is focused on the investigation of specific growth rate changes of $E.~coli$ wild type and mutant strains with defect of Hyd, FDH enzymes and FhlA regulatory protein in the presence of $N,N'$-dicyclohexylcarbodiimide (DCCD) and external formate various concentration during co-fermentation of glucose, glycerol and formate at pHs $5.5-7.5.$ The highest value of SGR was observed at pH 7.5. It was revealed that SGR depends on external formate concentration at all pHs. DCCD inhibitory effect was shown mainly at pH 7.5 and partially at pH 6.5 and 5.5. In the case of the F0F1-ATPase inhibition FhlA compensatory effect on SGR was revealed.
Svetlana H. Apoyan, Samvel M. Vardapetyan, Anahit M. Hovhannisyan, Gohar F. Mkrtchyan
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 12-15; https://doi.org/10.46991/pysu:b/2021.55.1.012

Abstract:
The amount of tannins in the leaves of stinging nettle was determined depending on the phenological phase (budding phase, mass flowering phase and fruiting phase). UV spectrophotometric and high performance liquid chromatographic (HPLC) methods were used to quantify tannins in the plant. It was found that the maximum accumulation of this group of substances in nettle leaves occurs in the fruiting phase. Based on the results of the study, the chromatographic method is optimal for the analysis of tannins in nettle leaves.
Tatevik O. Kamalyan, Petros S. Gukasyan, Samvel M. Vardapetyan, Oleg A. Kamalyan
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 1-6; https://doi.org/10.46991/pysu:b/2021.55.1.001

Abstract:
By the example of heterogeneous catalytic oxidation of propane the process of peroxide radicals transfer from the surface of catalysts into the reactor volume is studied. For comparison ZnO/SiO2 contacts obtained by depositing the active phase on the silica surface by sol-gel and chemical transport reaction (CTR) were used. It was established that for the case both the temperature of the radicals transfer from the surface to the volume and the value of the activation energy are lower than in the case. It was shown that the modification of the silica gel surface with zinc oxide by the CTR method is more effective as compared with the sol-gel method. It is established that in both cases the active phase of the catalyst exhibits paramagnetic properties. On the basis of the given, semi-artificial kinetic method of radical detachment, the obligatory mechanism of activation failed.
Marine A. Parsadanyan
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 39-45; https://doi.org/10.46991/pysu:b/2021.55.1.039

Abstract:
The study of complexes of groove binding ligand Hoechst 33258 (H33258) with Calf Thymus DNA has been carried out. The data obtained revealed that the melting curves of the complexes of H33258 with DNA are monophasic at low ligand concentrations (0 < r ≤ 0.2) and become biphasic at relatively high concentrations (0.2 < r ≤ 0.33). This effect was revealed to depend on the ionic strength of the solution, and can also occur at high concentrations of the ligand. Comparison of the obtained data with the results for poly(rA)-poly(rU) and poly(dA)-poly(dT) shows a coincidence in the case of DNA and poly(rA)-poly(rU), while in the case of poly(dA)-poly(dT) the melting curves become biphasic at low ligand concentrations and actually do not depend on the ionic strength of the solution.
Mikael M. Ginovyan, Naira Zh. Sahakyan, Margarit T. Petrosyan, Armen H. Trchounian
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 25-38; https://doi.org/10.46991/pysu:b/2021.55.1.025

Abstract:
Adverse effect of oxidative stress is a huge problem in medicine. In several circumstances, exogenous antioxidants are needed to regulate the amount of reactive species in the body. Plants are considered as a promising source for new antioxidant compounds. The goal of this study was to evaluate the antioxidant potential of extracts of the following herbs: Agrimonia eupatoria, Hypericum alpestre, Rumex obtusifolius and Sanguisorba officinalis using different chemical-based tests. GC-MS technique was used for identification of plant’s volatile bio-active constituents. The results revealed good potential of the tested herbs as sources for new antioxidant compounds.
Armenuhi V. Moghrovyan
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 46-51; https://doi.org/10.46991/pysu:b/2021.55.1.046

Abstract:
The article reports the results of microscopic studies of the oregano leaf in the pre-blossom period. In particular, the following anatomical and morphological features of the oregano leaf during the pre-blossom period were revealed: sinuous cuticle, multicellular simple trichomes, capitate trichomes, stomata, essential oil glands. The latter were located only in the central part, and were absent at the margins. The essential oil glands were of high density mostly in the central part of the raw materials preparation, which were harvested from the regions of dry climatic conditions as opposed to the raw materials harvested from the region of wet climatic conditions. The results of the investigation were definitely conditioned by the climatic features of the regions.
Nonna M. Grigoryan, Varuzhan S. Hovhannisyan
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 52-57; https://doi.org/10.46991/pysu:b/2021.55.1.052

Abstract:
The article presents two species of the genus Amauromyza (Diptera, Agromyzidae): A. leonuri (Spencer, 1971) and A. flavifrons (Meigen, 1830), which are widespread in Artsakh Republic. Their biological, ecological and morphological features, prevalence and intensity of infestation, as well as the types of mines are described.
Anna F. Karapetyan, Anna V. Grigoryan, Gevorg A. Avagyan
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 85-90; https://doi.org/10.46991/pysu:b/2021.55.1.085

Abstract:
Morphofunctional changes in the lungs of rats under the influence of aflatoxin B1 were studied. The data obtained indicate that aflatoxicosis causes marked regressive changes due to pulmonary insufficiency, which are accompanied by massive destruction of lung cells, the presence of altered fields of view of emphysema, diffuse inflammatory foci, as well as an increase in the number of mast cells.
Siranush А. Mkrtchyan, Razmik А. Dunamalyan, Lilit E. Ghukasyan, Marine A. Mardiyan, Karen K. Grigoryan
Proceedings of the YSU B: Chemical and Biological Sciences, Volume 55, pp 91-102; https://doi.org/10.46991/pysu:b/2021.55.1.091

Abstract:
The developmental and behavioral disabilities remain high in children and in adults who were born preterm. In this case assessment of quality of life and development of preterm infants can be very informative and interesting. This is a prospective longitudinal (at 3, 6, 9 and 12 months) study of preterm birth and term control infants selected from pediatric polyclinics of Yerevan. The quality of life (QL) measures were done with QUALIN questionnaire and the developmental measures with Battelle Developmental Inventory. A total of 71 preterm and 105 term control infants underwent study. Among 71 preterm birth infants, who selected on the study at 3 months, 40 infant's score on the BDI was <–1 SD and 1 infants' score on the BDI was <–2 SD. However, at the age of 12 months 32 of these same children showed a BDI score >85. Parents and pediatricians reported worse QL for of preterm infants compared with control group. At same time parents of preterm infants reported better QL for their children compared with pediatricians. The lowest QL and developmental scores among preterm children were detected at 3 months. Improvement of QL and developmental score was observed in the next age groups.
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