East European Journal of Physics https://periodicals.karazin.ua/eejp <p>EEJP is an international peer-reviewed journal devoted to experimental and theoretical research on nuclear physics, cosmic rays and particles, high-energy physics, solid-state physics, plasma physics and controlled thermonuclear fusion, physics of charged particle beams, plasma electronics, radiation materials science, physics of thin films, condensed matter physics, functional materials and coatings, technical thermal physics and industrial power, medical physics and physical technologies in an interdisciplinary context.</p> <p>EEJP registered by the order of Ministry of Education and Science of Ukraine <strong>No. 1643 of 28.12.2019</strong>, and included in the list of scientific professional Editions of Ukraine (<strong>category “A”, specialty: 104, 105</strong>), in which results of dissertations for obtaining Ph.D. and Dr. Sci. degrees in physical and mathematical sciences can be published.</p> <p>The Journal is a part of the <strong>Web of Science Core Collection (ESCI)&nbsp;</strong>scientometric platform and indexed by&nbsp;<strong>SCOPUS</strong>.</p> <p><a title="SCImago Journal &amp; Country Rank" href="https://www.scimagojr.com/journalsearch.php?q=21101018929&amp;tip=sid&amp;exact=no"><img src="https://www.scimagojr.com/journal_img.php?id=21101018929" alt="SCImago Journal &amp; Country Rank" border="0"></a>&nbsp;</p> <p>&nbsp;</p> V.N. Karazin Kharkiv National University en-US East European Journal of Physics 2312-4334 <p>Authors who publish with this journal agree to the following terms:<br><br></p> <ol type="a"> <ul> <li class="show">Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a&nbsp;<a href="http://creativecommons.org/licenses/by/4.0/" target="_new">Creative Commons Attribution License</a> that allows others to share the work with an acknowledgment of the work's authorship and initial publication in this journal.</li> </ul> </ol> <ol type="a"> <ul> <li class="show">Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgment of its initial publication in this journal.</li> </ul> </ol> <ol type="a"> <ul> <li class="show">Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See&nbsp;<a href="http://opcit.eprints.org/oacitation-biblio.html" target="_new">The Effect of Open Access</a>).</li> </ul> </ol> Plasmon-Exciton Interaction in Perspective Hetero-Systems https://periodicals.karazin.ua/eejp/article/view/20950 <p>Surface plasmons and excitons have been widely studied experimentally and theoretically for various material systems. However, a number of aspects require further deeper study and understanding, among which the connection of these quasi-particles occupies an important place. New physical effects arise when plasmons and excitons in nanostructures begin to be localized at certain small distances, as a result, we can talk about their coupling. Complex systems containing the excitation of plasmons and excitons, as well as their coupling, show interesting optical properties that they cannot exhibit individually. In this type of system, the plasmon enhances the coupling between the system and the external field, and the exciton controls certain spectral properties, which opens up new possibilities for tuning their optical response. The transferred energy between plasmons and excitons becomes an important factor affecting their interaction when the resonance frequency of the localized plasmon is very close to the molecular energy transition frequency. Two types of coupling can occur depending on the ratio between the strength of the coupling and the energy losses of individual components in the system, namely strong and weak. In addition to the mutual coupling between the plasmon and the exciton, their different linewidths and ability to couple to an external field provide a variety of means to tune the optical properties of hybrid systems. Thus, it enables precise control of light at the nanometer scale, opening up possibilities for new electronics and photonics applications. In this review, we highlight the features of weak and strong modes of plasmon-exciton coupling, modern trends, and perspectives in the study of hetero-systems semiconductor–metal, metal–2D material, semiconductor–molecule, etc. Semiconductor-metal hybrid nanostructures open up exciting opportunities for the study of quantum phenomena, optical processes, and multiparticle interactions and confidently lead to application in new photonics devices.</p> Natalia Ohon Tetiana Bulavinets Iryna Yaremchuk Rostyslav Lesyuk Copyright (c) 2022 Natalya Ogon, Tetyana Bulavinets, Iryna Yaremchuk, Rostyslav Lesyuk http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 6 22 10.26565/2312-4334-2022-4-01 A Bio-Thermal Convection in a Porous Medium Saturated by Nanofluid Containing Gyrotactic Microorganisms Under an External Magnetic Field https://periodicals.karazin.ua/eejp/article/view/20391 <p>The study of thermal convection in porous media saturated by nanofluid and microorganisms is an important problem for many geophysical and engineering applications. The concept of a mixture of nanofluids and microorganisms has attracted the interest of many researchers due to its ability to improve thermal properties and, as a result, heat transfer rates. This property is actively used both in electronic cooling systems and biological applications. Thus, the purpose of this research is to study biothermal instability in a porous medium saturated by a water-based nanofluid containing gyrotactic microorganisms in the presence of a vertical magnetic field. Given the presence of an external magnetic field in both natural and technological situations, we were motivated to perform this theoretical research. Using the Darcy-Brinkman model, a linear analysis of the convective instability has been considered for both-free boundaries, taking into account the effects of Brownian diffusion and thermophoresis. The Galerkin method was used to perform this analytical study. We have established that heat transfer is accomplished by stationary convection without oscillatory movements. In stationary convection regimes, metal oxide nanofluids (<em>Al<sub>2</sub>O<sub>3</sub></em>), metallic nanofluids (<em>Cu</em>,&nbsp;<em>Ag</em>), and semiconductor nanofluids (<em>TiO<sub>2</sub>,&nbsp;SiO<sub>2</sub></em>) are analyzed. Increasing the Chandrasekhar and Darcy numbers improve system stability significantly, but increasing porosity and modified bioconvection Rayleigh-Darcy number speed up the beginning of instability. To determine the transient behavior of heat and mass transports, a non-linear theory based on the representation of the Fourier series method is applied. In small time intervals, the transitional Nusselt and Sherwood numbers exhibit an oscillatory character. The Sherwood numbers (mass transfer) in the time interval reach stationary values faster than the Nusselt numbers (heat transfer). This research might help with seawater convection in the oceanic crust as well as the construction of biosensors.</p> Michael I. Kopp Volodymyr V. Yanovsky Ulavathi S. Mahabaleshwar Copyright (c) 2022 Michael I. Kopp, Volodymyr V. Yanovsky, Ulavathi S. Mahabaleshwar http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 23 47 10.26565/2312-4334-2022-4-02 Analysis of α-208Pb Elastic Scattering at a Wide Energies by the S-Matrix Model https://periodicals.karazin.ua/eejp/article/view/19292 <p>Investigation of hadron interaction with nuclei is important source of information about nuclear structure and mechanisms of nuclear interaction. Approaches based on different potentials (optical model) or scattering matrix (S-matrix) are used for theoretical description of appropriate experimental data.</p> Yuri A. Berezhnoy Gennadiy M. Onyshchenko Pylyp E. Kuznietsov Volodymyr V. Pilipenko Ivan I. Yakymenko Copyright (c) 2022 Yu.A. Berezhnoy, G.M. Onyshchenko, P.E. Kuznetcov, V.V. Pilipenkoa, I.I. Yakymenko http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 48 56 10.26565/2312-4334-2022-4-03 Study of the Nuclear Structure for Some Nuclei Using Self-Consistent RPA Calculations with Skyrme-Type Interaction https://periodicals.karazin.ua/eejp/article/view/20358 <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; In the present research, some static and dynamic nuclear properties of the closed-shell nuclei; <sup>58</sup>Ni, <sup>90</sup>Zr, <sup>116</sup>Sn, and <sup>144</sup>Sm nuclei have been studied using the Random Phase Approximation (RPA) method framework and different Skyrme parameterizations, particularly SyO-, Sk255, SyO+, SLy4, BSk17, and SLy5. In particular, in studies of static properties such as nuclear densities for neutrons, protons, mass, and charge densities with their corresponding rms radii, the single-particle nuclear density distributions All the obtained results agreed well with the relevant experimental data. Concerning the dynamic properties, the excitation energy, transition density, and giant resonance modes for the excitation to the low-lying negative partite excited states 1–, 3–, 5–, and 7– have also been studied. The findings indicate that estimates of RPA with Skyrme-type interactions are a good way to describe the properties of the structure of even-even, closed-shell nuclei.</p> Noor M. Kareem Ali A. Alzubadi Copyright (c) 2022 Noor M. Kareem, Ali A. Alzubadi http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 57 71 10.26565/2312-4334-2022-4-04 Exotic Structure of 17Ne-17N and 23Al-23Ne Mirror Nuclei https://periodicals.karazin.ua/eejp/article/view/20359 <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; In terms of the core nucleus plus valence nucleon, shell-model calculations using two model spaces and interactions, the relationship between a nucleus' proton skin, and the difference in proton radii of mirror pairs of nuclei with the same mass number are investigated. In this work, two pairs of mirror nuclei will be studied: <sup>17</sup>Ne-<sup>17</sup>N and <sup>23</sup>Al-<sup>23</sup>Ne. For <sup>17</sup>Ne-<sup>17</sup>N nuclei, p-shell and mixing of psd orbits are adopted with Cohen-Kurath (ckii) and psdsu3 interactions. While for <sup>23</sup>Al-<sup>23</sup>Ne, the sd-shell and sdpf shell are adopted with the universal shell model (USD) and sdpfwa interactions. Also, the ground state density distributions, elastic form factors, and root mean square radii of these pairs' nuclei are studied and compared with available experimental data. . In general, it was found that the rms radius of the valence proton(s) is larger than that of the valence neutron(s) in its mirror nucleus. The results show that these nuclei have the exotic structure of a halo or skin.</p> Ruqaya A. Mohammed Wasan Z. Majeed Copyright (c) 2022 Ruqaya A. Mohammed, Wasan Z. Majeed http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 72 79 10.26565/2312-4334-2022-4-05 Heavy-Light Meson Masses in the Framework of Trigonometric Rosen-Morse Potential Using the Generalized Fractional Derivative https://periodicals.karazin.ua/eejp/article/view/20419 <p>Trigonometric Rosen-Morse Potential is employed as a mesonic potential interaction. The extended Nikiforov-Uvarov method is used to solve the N-radial Fractional Schrödinger equation analytically. Using the generalized fractional derivative, the energy eigenvalues are obtained in fractional forms. The current findings are used to calculate the masses of mesons such as charmonium, bottomonium, and heavy-light mesons. The current findings are superior to those of other recent studies and show good agreement with experimental data as a result, the fractional parameter is crucial in optimizing meson masses.</p> Mohamed Abu-Shady Etido P. Inyang Copyright (c) 2022 Mohamed Abu-Shady, Etido P. Inyang http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 80 86 10.26565/2312-4334-2022-4-06 Analytical Solutions to The Schrödinger Equation with Collective Potential Models: Application to Quantum Information Theory https://periodicals.karazin.ua/eejp/article/view/20926 <p>In this study, the energy equation and normalized wave function were obtained by solving the Schrödinger equation analytically utilizing the Eckart-Hellmann potential and the Nikiforov-Uvarov method. Fisher information and Shannon entropy were investigated. Our results showed higher-order characteristic behavior for position and momentum space. Our numerical results showed an increase in the accuracy of the location of the predicted particles occurring in the position space. Also, our results show that the sum of the position and momentum entropies satisfies the lower-bound Berkner, Bialynicki-Birula, and Mycieslki inequality and Fisher information was also satisfied for the different eigenstates. This study's findings have applications in quantum chemistry, atomic and molecular physics, and quantum physics.</p> Etido P. Inyang Funmilayo Ayedun Efiong A. Ibanga Kolawole M. Lawal Copyright (c) 2022 Funmilayo Ayedun, Etido P. Inyang, Efiong A. Ibanga, Kolawole M. Lawal http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 87 98 10.26565/2312-4334-2022-4-07 A Study of Photoneutron Reactions Using Statistical Analysis https://periodicals.karazin.ua/eejp/article/view/20945 <p>The well-known inputs for determining the reaction cross section are nuclear level density (NLD) and -ray strength functions. In this work, effects of -ray strength functions and NLD models on photoneutron reactions of <sup>76<em>,</em>77<em>,</em>78</sup>Se isotopes are analyzed by using the latest version of TALYS computer code. For -ray strength functions, macroscopic and microscopic options which are available in the TALYS, are used in the calculations. Kopecky-Uhl and Brink Axel -ray strength function models as macroscopic options, Hartree-Fock BCS tables, Hartree-Fock Bogolyubov tables and Goriely’s hybrid model as microscopic options are preferred. The statistical analysis is carried out to determine the -ray strength function that reproduces the experimental data quite well. And then, calculations of photoneutron cross section are redone by using the determined -ray strength function via the NLD models. The Constant Temperature Model (CTM), Back Shifted Fermi Gas Model (BSFGM) and Generalized Superfluid Model (GSM) are preferred to use in NLD calculations. The predictions are compared with each other and the available experimental data. EXFOR library is used to take all experimental data.</p> Deniz Canbula Bora Canbula Copyright (c) 2022 Deniz Canbula, Bora Canbula http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 99 103 10.26565/2312-4334-2022-4-08 Effect of Electric Field Modulation on The Onset of Electroconvection in a Couple Stress Fluid https://periodicals.karazin.ua/eejp/article/view/18808 <p>The problem of a convectional instability in a horizontal dielectric fluid layer with electric field modulation under couple stress fluid is examined. The horizontal dielectric upper boundary fluid layer is cooled, and the lower boundary is subjected to an isothermal boundary condition. The regular perturbation method based on the small magnitude of modulation is used to compute the critical Rayleigh number and the corresponding wavenumber. The solidity of the system is the characterised by a correction Rayleigh number, which is computed as a function of thermal, electric, and couple stress parameters and the frequency of electric field modulation. Some of the known findings are retrieved as specific cases in this study. It is demonstrated that the onset of the convection may be advanced or delayed by the proper regulation of different regulation parameters. The outcomes of this study have potential implications for the control of electroconvection with a time-dependent electric field.</p> Chandrappa Rudresha Chandrashekar Balaji Venkatesh Vidya Shree Sokalingam Maruthamanikandan Copyright (c) 2022 Chandrappa Rudresha, Chandrashekar Balaji, Venkatesh Vidya Shree, Sokalingam Maruthamanikandan http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 104 111 10.26565/2312-4334-2022-4-09 Effect of Magnetic Field Dependent Viscosity on Darcy-Brinkman Ferroconvection with Second Sound https://periodicals.karazin.ua/eejp/article/view/20357 <p>The problem of buoyancy-driven convection in a ferromagnetic fluid saturated porous medium with the Maxwell-Cattaneo law and MFD viscosity is investigated by the method of small perturbation. The fluid motion is described using the Brinkman model. It is assumed that the fluid and solid matrices are in local thermal equilibrium. For simplified boundary conditions, the eigenvalue problem is solved exactly, and closed form solutions for stationary instability are obtained. Magnetic forces and second sound were found to enhance the beginning of Brinkman ferroconvection. However, ferroconvection is hampered when the porous parameters are increased. The results show that MFD viscosity inhibits the beginning of Darcy-Brinkman ferroconvection and that MFD viscosity stabilizing effect is decreased when the magnetic Rayleigh number is significant. Furthermore, it is demonstrated that oscillatory instability arises before stationary instability, assuming that the Prandtl and Cattaneo numbers are sufficiently large.</p> Venkatesh Vidya Shree Chandrappa Rudresha Chandrashekar Balaji Sokalingam Maruthamanikandan Copyright (c) 2022 Venkatesh Vidya Shree, Chandrappa Rudresha, Chandrashekar Balaji, Sokalingam Maruthamanikandan http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 112 117 10.26565/2312-4334-2022-4-10 Effect of Silver Nanoparticles SILAR Cycle on TiO2 Nanoparticles Thin Film: Optical and Structural Study https://periodicals.karazin.ua/eejp/article/view/20948 <p>Titanium dioxide (TiO<sub>2</sub>) has gained a lot of research interests due to its applicability in electronic materials, energy, environment, health &amp; medicine, catalysis etc as a result of its high permittivity, refractive index, efficiency, low-cost chemical inertness, eco-friendliness, photocatalytic activity, photostability and ability of decomposing a wide variety of organic compounds. In this study, the effect of silver nanoparticles (AgNPs) deposited through Successive Ionic Layer Adsorption and Reaction (SILAR) on the optical, structural and morphological properties of TiO<sub>2</sub> was explored systematically. The investigation was achieved via a combined effect of UV-vis spectroscopy, Scanning Electron Microscope (SEM) and X-ray Diffractometer (XRD) characterizing tools. As illustrated from the SEM micrographs, introduction of AgNPs result to enhanced nucleation and films growth with presence of shining surface which can be seen to contribute to good photon management through enhanced light scattering. The XRD results showed that, the presence of AgNPs on TiO<sub>2</sub> results to peaks corresponding to that of the TiO<sub>2</sub> crystallographic planes with no silver peaks detected due to its low concentration in the nanocomposite which shows that it was just homogeneously distributed on the surface of the TiO<sub>2</sub> nanoparticles. The UV-Vis results show a red shift to higher wavelength, showing an increase in visible light absorption which can be ascribed to the strong field effect of the Localized Surface Plasmon Resonance (LSPR). There was a decrease in band gap edge with introduction of AgNPs which indicated an increase in the optical conductivity of the AgNPs modified film.</p> Daniel Thomas Eli Danladi Mary T. Ekwu Philibus M. Gyuk Muhammed O. Abdulmalik Innocent O. Echi Copyright (c) 2022 Daniel Thomas, Eli Danladi, Mary T. Ekwu, Philibus M. Gyuk, Muhammed O. Abdulmalik, Innocent O. Echi http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 118 124 10.26565/2312-4334-2022-4-11 Numerical Study of 25.459% Alloyed Inorganic Lead-Free Perovskite CsSnGeI3-Based Solar Cell by Device Simulation https://periodicals.karazin.ua/eejp/article/view/20949 <p>The toxic lead component as well as the expensive and less stable spiro-OMeTAD in perovskite solar cells (PSCs) pose a great deal of hindrance to their commercial viability. Herein, a computational approach towards modeling and simulation of all inorganic cesium tin-germanium triiodide (CsSnGeI<sub>3</sub>) based perovskite solar cell was proposed and implemented using solar cell capacitance simulator (SCAPS–1D) tool. Aluminium doped zinc oxide (ZnO:Al) and Copper Iodide (CuI) were used as electron and hole transport layers (ETL and HTL) respectively. The initial device without any optimization gave a power conversion efficiency (PCE) of 24.826%, fill factor (FF) of 86.336%, short circuit current density (<em>J</em><sub>sc</sub>) of 26.174 mA/cm<sup>2</sup> and open circuit voltage (<em>V</em><sub>oc</sub>) of 1.099 V. On varying the aforementioned parameters individually while keeping others constant, the optimal values are 1000 nm for absorber thickness, 10<sup>14</sup> cm<sup>-3</sup> for absorber layer defect density, 50 nm for ETL thickness, 10<sup>17</sup> cm<sup>-3</sup> for ETL doping concentration and 260 K for temperature. Simulating with these optimized values results to PCE of 25.459%, <em>V</em><sub>oc</sub> of 1.145 V, <em>J</em><sub>sc</sub> of 25.241 mA/cm<sup>2</sup>, and a FF of 88.060%. These results indicate that the CsSnGeI<sub>3</sub> is a viable alternative absorbing layer for usage in the design of a high PCE perovskite solar cell device.</p> Muhammed O. Abdulmalik Eli Danladi Rita C. Obasi Philibus M. Gyuk Francis U. Salifu Suleiman Magaji Anselem C. Egbugha Daniel Thomas Copyright (c) 2022 Muhammed O. Abdulmalik, Eli Danladi, Rita C. Obasi, Philibus M. Gyuk, Francis U. Salifu, Suleiman Magaji, Anselem C. Egbugha, Daniel Thomas http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 125 135 10.26565/2312-4334-2022-4-12 Assessment of Explicit Models Based on the Lambert W-Function for Modeling and Simulation of Different Dye-Sensitized Solar Cells (DSSCs) https://periodicals.karazin.ua/eejp/article/view/18813 <p>In this paper, the characteristic points were used as input data in five different explicit models based on Lambert W-function for the extraction of model parameters of three DSSCs. Moreover, these model parameters for given values of voltages were used to obtain the corresponding currents for the simulation of the DSSCs. The results show that the sign of the model parameter does not matter for methods that do not have series resistance and shunt resistance. However, when R<sub>sh</sub> was negative the five-parameter single-diode model failed to yield good curve fit except when R<sub>sh</sub> was neglected and four-parameter model used. Moreover, all the model parameters for DSSCs with bitter gourd dye were regular and yielded good curve fit for all the models. On the hand, DSSCs with R<sub>sh</sub> values negative were handled with four-parameter model to obtain good curve fit. Thus, the sign of model parameter matters in simulation of DSSC using single-diode model.</p> Jamu Yerima Dunama William Alkali Babangida Sabastine Ezike Copyright (c) 2022 Jamu Benson Yerima, Dunama William, Alkali Babangida, Sabastine Chinedu Ezike http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 136 144 10.26565/2312-4334-2022-4-13 Study of CIGS Pseudo-Homojunction Thin Film Solar Cell using SCAPS-1D https://periodicals.karazin.ua/eejp/article/view/18826 <p>The present modelling study reports the performance of defected CIGS pseudo-homojunction thin film solar cell (P-HTFSC) and determines its optimum parameters for high performance using the Scaps-1D software under the AM1.5 illumination and the operating temperature of 300 K. To focus the discussion on the optimal parameters (thickness, doping concentrations, deep/interface defect concentrations and bandgap) for the ZnO, CdS, ODC and CIGS thin film layers, cross sectional (1D) simulations have been performed on the ZnO/CdS/ODC/CIGS P-HTFSC device for obtaining its optimal structure that confers high light-into-electricity conversion efficiency. The four light J-V characteristics (short-circuit current: JSC, open-circuit voltage: VOC, fill factor: FF and conversion efficiency: ) have been used as indicators to evaluate the device performances. Simulation outcomes have proved that for a best performance for CIGS P-HTFSC device, the optimal thickness for CIGS and ODC layers should be small than 2 µm and few nm, respectively, while the optimal defect concentration within the layer should be 1013 cm-3 and between 1013 cm-3-1018 cm-3, respectively.</p> Samah Boudour Idris Bouchama Samiha Laidoudi Walid Bedjaoui Leila Lamiri Ouafia Belgherbi Siham Aziez Copyright (c) 2022 Samah Boudour, Idris Bouchama, Samiha Laidoudi, Walid Bedjaoui, Leila Lamiri, Ouafia Belgherbi, Siham Aziez http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 145 152 10.26565/2312-4334-2022-4-14 Sensitivity and Evanescent Field Study of a Uniaxial Anisotropic Planar Waveguide Based Optical Sensor https://periodicals.karazin.ua/eejp/article/view/18831 <p>The effect of source, geometrical and physical parameters of slab waveguide on the sensitivity of optical sensor and its evanescent field have been investigated. The waveguiding film of LiNbO3 was fabricated and the observations revealed that the maximal sensitivities of Transverse Magnetic (TM) modes and their corresponding frequencies are greater than those for Transverse Electric (TE) modes. Furthermore, the optimal source parameters improve the maximal sensitivity and evanescent field in the cover. However, the increment in the core thickness reduces the sensitivity of sensor due to reduction in evanescent field in the cover. The sensitivity of sensor was observed as a function of refractive indices of cover, core and the substrate. The increase in refractive indices of cover and core, directly affect the sensitivity while an inverse relation has been observed regarding increase in the refractive index of the substrate. It is worth noting that, any changes in the physical parameters of waveguide sensor show an insignificant effect on the evanescent fields.</p> Abdelbaki Cherouana Idris Bouchama Abdelhalim Bencheikh Samah Boudour Muhammad Akhtar Copyright (c) 2022 Abdelbaki Cherouana, Idris Bouchama, Abdelhalim Bencheikh, Samah Boudour, Muhammad Akhtar http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 153 163 10.26565/2312-4334-2022-4-15 An Ab Initio Analysis of Structural, optical, Electronic, and Thermal Properties of Cubic SrSnO3 using Wein2k https://periodicals.karazin.ua/eejp/article/view/19297 <p>This paper investigated the structural, optical, electronic and thermal characteristics of SrSnO<sub>3</sub> perovskites that were calculated using the density functional theory. Software called WEIN2K is used to perform the calculation. According to our calculations, the band gap energy of the SrSnO<sub>3</sub> is roughly 4.00 eV and it adopts a distorted cubic shape in the space group <em>Pm3<sup>-</sup>m</em>. The band structure and partial density of state reflects the major contribution of O 2p in the valence band while 5s orbital from Sn in the conduction band. The electron density plot significantly shows the contribution different clusters SrO<sub>12</sub> and SnO<sub>6</sub> that plays crucial role in electronic and optical properties. The creation of covalent bonds between the atoms of Sn and O as well as the ionic interaction between the atoms of Sr and O are both demonstrated by the electron density graphs and SCF calculation. The refractive index and extinction coefficient directly correlated with the real and imaginary part of complex dielectric function. Real part of dielectric function shows higher values at two major point of energy 3.54 eV and 9.78 eV associated with the absorption and optical activity of SrSnO<sub>3</sub>. Negative part of imaginary dielectric function part suggests metallic behavior also supported by -grep lapw method. Thermoelectric and thermal conductivity properties suggest the power factor need to be improved for the device application.</p> Arya Aditya Kumar Varsha Yadav Hari Pratap Bhaskar Sushil Kumar Satyam Kumar Upendra Kumar Copyright (c) 2022 Arya, Aditya Kumar, Varsha Yadav, Hari Bhaskar, Sushil Kumar, Satyam Kumar, Upendra Kumar http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 164 170 10.26565/2312-4334-2022-4-16 Utilizing Spectroscopy and Optical Microscopy to Characterize Titanium Dioxide Thin Films https://periodicals.karazin.ua/eejp/article/view/20378 <p>This paper presents the surface electronic structure and morphological characteristics of the nano-crystalline titanium dioxide (nc&nbsp;TiO<sub>2</sub>) films derived from the two different sol-gels. Using Scanning tunneling microscopy/spectroscopy (STM/S), it was found that the particles of nc-TiO<sub>2</sub> produced from batch A have a surface band gap of ~3.3&nbsp;eV while the particles of nc-TiO<sub>2</sub> produced from batch B have a surface band gap of ~2.6&nbsp;eV. On other hand, the small particles have aggregated together to form larger particles ranging from&nbsp;~120&nbsp;nm to 150&nbsp;nm in size and distributed randomly over the surface of the batch A nc-TiO<sub>2 </sub>films. For batch B nc-TiO<sub>2</sub>films, the small particles have formed larger particles but with their size ranging from 200&nbsp;nm to 225&nbsp;nm. That is ascribed to differences between sol-gels used to prepare nc-TiO<sub>2</sub> films. As a result of that, the electric power of batch A nc-TiO<sub>2</sub>/P3HT solar cells is enhanced by more than 8 times in comparison with batch B solar cells.</p> Hmoud Al Dmour Copyright (c) 2022 Hmoud Al Dmour http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 171 175 10.26565/2312-4334-2022-4-17 Enhancement of Structural and Optical Properties of CMC/PAA Blend by Addition of Zirconium Carbide Nanoparticles for Optics and Photonics Applications https://periodicals.karazin.ua/eejp/article/view/20832 <p>Nanocomposites of (CMC-PAA-ZrC) &nbsp;made with different nano zirconium carbide percentages by casting method (0, 1.5, 3, 4.5, and 6) wt%. The results showed that FTIR spectra shift in peak position and change in shape and intensity, compared with pure (CMC-PAA) blend. Microscopic photographs show a clear difference in the samples when increasing proportions of zirconium carbide nanoparticles, when the concentration of zirconium carbide NP reached 6% wt, the nanoparticles make up a continuous network inside (CMC-PAA) blend. Structural and optical characteristics have investigated the findings showed that the absorption of (CMC-PAA-ZrC) nanocomposites increases with increasing of ZrC NPs, while transmission decrease. The absorption coefficient, extinction coefficient, refractive index, real and imaginary parts of dielectric and optical conductivity are increasing with rises concentration of ZrC. Also optical energy gap decreased from 4.9 eV to 4.05 eV and from 4.5 eV to 3.65 eV for allowed and forbidden indirect transition respectively with increasing ZrC NPs. The results indicate that the (CMC-PAA-ZrC) &nbsp;nanostructures can be considered as promising materials for optoelectronics applications.</p> Majeed Ali Habeeb Zainab Sabry Jaber Copyright (c) 2022 Majeed Ali Habeeb, Zainab Sabry Jaber http://creativecommons.org/licenses/by/4.0 2022-11-10 2022-11-10 4 176 182 10.26565/2312-4334-2022-4-18 Preparation and Characterization of Cu2CrSnS4 Thin Films Deposited at Different Temperatures https://periodicals.karazin.ua/eejp/article/view/20834 <p>In this study, Cu<sub>2</sub>CrSnS<sub>4</sub> thin films are prepared using chemical pyrolysis technique at various deposition temperatures (200, 250, 300, 350, 400 and 450 <sup>°</sup>C) and without any annealing process. The structure characteristics of the films have been studied by X ray diffraction (XRD), micro-Raman spectroscopy, and Field Emission Scanning Electron Microscope (FESEM), while the optical characteristics are investigated by UV-Visible spectrophotometry, and the electrical properties aree described by Hall Effect test. Results of XRD for Cu<sub>2</sub>CrSnS<sub>4</sub> (CCTS) films showed the tetragonal crystal structure of stannite phase with (112) preferred orientation. The results of&nbsp;Raman&nbsp;spectroscopy of the prepared&nbsp;CCTS&nbsp;thin films showed a clear peak at ~ 336 cm<sup>-1</sup>. Furthermore, the morphology results and through (FESEM) images of thin films surface showed different forms and shapes with different granular size ranging from 40 to 294 nm. Optical examination of the ultraviolet-visible spectrum showed an optical energy gap of (1.69-1.59 eV) which are considered to be suitable for thin films solar cells applications. The electrical measurements through Hall Effect test showed that the films have charge carriers of (p-type). From results analysis, the optimized temperature of the prepared (CCTS) samples&nbsp;was 350 <sup>o</sup>C.</p> Huda Talib Nabeel A. Bakr Mohammed A. Abed Copyright (c) 2022 Huda Talib, Nabeel A. Bakr, Mohammed A. Abed http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 183 189 10.26565/2312-4334-2022-4-19 Effect of Solvent Polarity on the Absorption and Fluorescence Spectra of Nicotinamide: Determination of Ground and Excited State Dipole Moments https://periodicals.karazin.ua/eejp/article/view/20363 <p>Nicotinamide (NIC) is an amide-form vitamin with a carboxamide group at b positions that is involved in a variety of biological activities. The drugs contain functional groups which control the type and degree of interaction with different solvents. In this research, the ground and excited state dipole moments of nicotinamide (NIC) were estimated using solvatochromic effects and computational work. A general overview of solvent effects on the electronic absorption and fluorescence spectra of NIC is presented. In both spectra, pronounced solvatochromic effects were observed, and the shift of emission peaks was larger than the corresponding absorption spectra. The experimental ground state ( μ<sub>g</sub> ) and excited state (μ<sub>e</sub>) dipole moments of NIC are estimated from solvatochromic shifts of absorption and fluorescence spectra. The differences between the excited and ground state dipole moments determined by all the methods are quite similar. The HOMO-LUMO energy band gaps were calculated and found to be 5.566 eV. The excited state dipole moment is found to be higher than those of the ground state for all of the used methods, and it is attributed to the more polar excited state of NIC. Finally, the observed spectral properties, measured values of dipole moments, and electronic structures of NIC in different solvents provide important details about charge distribution and solute-solvent interactions that may be helpful in the investigation of these molecules in biological systems.</p> Ataklti Abraha Gebreyohanes Abebe Belay Getachew Alemu Copyright (c) 2022 Ataklti Abraha Gebreyohanes, Abebe Belay, Getachew Alemu http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 190 199 10.26565/2312-4334-2022-4-20 Relativistic Symmetries of Bosonic Particles and Antiparticles in the Background of the Position-Dependent Mass for the Improved Deformed Hulthen Plus Deformed Type-Hyperbolic Potential in 3D-EQM Symmetries https://periodicals.karazin.ua/eejp/article/view/20865 <p>The bound state solutions of the deformed Klien-Gordon equation have been determined in the three-dimensional extended relativistic quantum mechanics 3D-ERQM symmetries using position-dependent mass (PDM) with unequal scalar and vector potential for the improved Hulthén plus improved deformed type-hyperbolic potential (PDM-SVID(H-TP)) models. PDM with unequal scalar and vector potential for the Hulthén plus deformed type-hyperbolic potential (PDM-(SVH-DTP)) models, as well as a combination of radial terms, which are coupled with the coupling <strong>LΘ</strong>, which explains the interaction of the physical features of the system with the topological deformations of space-space. The new relativistic energy eigenvalues have been derived using the parametric Bopp shift method and standard perturbation theory which is sensitive to the atomic quantum numbers (<em>j,l,s,m</em>), mixed potential depths (<em>V<sub>0</sub>S<sub>0</sub>V<sub>1</sub>S<sub>1</sub></em>), the rest, and perturbed mass (<em>m<sub>0</sub>,m<sub>1</sub></em>), the screening parameter's inverse <em>α</em>, and noncommutativity parameters (<em>Θ,τ,χ</em>). Within the framework of 3D-ERQM symmetries, we have treated certain significant particular instances that we hope will be valuable to the specialized researcher. We have also treated the nonrelativistic limit and applied our obtained results to generate the mass spectra of heavy-light mesons (HLM) such as cc<sup>-</sup> and bb<sup>-</sup>&nbsp;under PDM-SE with improved deformed Hulthén plus improved hyperbolic potential (PDM‑ID(H-TP)) models. When the three simultaneous limits (<em>Θ,τ,χ</em>) were applied, we recovered the normal results of relativistic in the literature ( 0,0,0) for the PDM‑ID(H-TP)) models.</p> Abdelmadjid Maireche Copyright (c) 2022 Abdelmadjid Maireche http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 200 212 10.26565/2312-4334-2022-4-21 Detection of Lysozyme Amyloid Fibrils Using Trimethine Cyanine Dyes: Spectroscopic and Molecular Docking Studies https://periodicals.karazin.ua/eejp/article/view/20979 <p>Due to their unique photophysical and photochemical properties and high sensitivity to the beta-pleated motifs, cyanine dyes have found numerical applications as molecular probes for the identification and characterization of amyloid fibrils <em>in vitro</em> and the visualization of amyloid inclusions <em>in vivo. </em>In the present study the spectroscopic and molecular docking techniques have been employed to evaluate the amyloid sensitivity and the mode of interaction between the trimethine cyanine dyes and native (LzN) and fibrillar (LzF) lysozyme. It was found that the trimethine association with non-fibrilar and fibrillar lysozyme is accompanied by the changes in dye aggregation extent. The molecular docking studies between trimethine dyes and lysozyme in the native and amyloid states indicate that: i) trimethines tend to form the most stable complexes with deep cleft of the native lysozyme; ii) the dye binding with non-fibrillar protein is governed by the hydrophobic interactions, π-stacking contacts between aromatic or cyclopentane ring of the cyanine and Trp in position 63 or 108 and hydrogen bonds between the OH-groups of the trimethines and acceptor atoms of Asp 101 (AK3-7) and Gln 57 (AK3-8) of LzN; iii) cyanine dyes form the energetically most favorable complexes with the groove Gly 2-Leu 4/Ser 8-Trp 10 of the lysozyme fibril core; iv) cyanines-LzF interaction is stabilised by hydrobhobic contacts, π-stacking interaction and hydrogen bonds. The dyes AK3-7, AK3-5 and AK3-11 were selected as the most prospective amyloid probes.</p> Olga Zhytniakivska Uliana Tarabara Atanas Kurutos Kateryna Vus Valeriya Trusova Galyna Gorbenko Copyright (c) 2022 Olga Zhytniakivska, Uliana Tarabara, Atanas Kurutos, Kateryna Vus, Valeriya Trusova, Galyna Gorbenko http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 213 221 10.26565/2312-4334-2022-4-22 A Demonstration Bench for Representing the Character of Phase Transitions of the First and Second Kind https://periodicals.karazin.ua/eejp/article/view/20982 <p>The paper presents the description of a demonstration bench, which includes a mathematical model and analysis tools for understanding the features of phase transitions of the first and second kind. The advantage of this demonstration bench is the rejection of all phenomenology and the obvious limitation of the application of various approximations and hypotheses. The description is formed on the well-known equations of hydrodynamics, which are well-tested and are a reliable basis for the construction of realistic models. The Proctor-Sivashinsky model, which was used to describe the process of convection development in a thin layer of liquid with poorly conductive heat boundaries, is the basis for the demonstration bench. Exactly this model allows to observe phase transitions of the first and second kind. The feature of the model is that it allocates one spatial scale of interaction, leaving for the evolution of the system the possibility to choose the nature of symmetry. All spatial disturbances of the same size but of different orientation interact with each other. This allows us not to distract from the main task of this work, which is to demonstrate the process of structure formation as a result of a cascade of phase transitions. The mechanism of phase transitions associated with the presence of minimums of the interaction coefficients of modes of the spectrum of the instability. There are a large number of structural defects, which appear as attributes of phase transition. The instability spectrum modes interference is the reason of the high rate of correlations in the propagation of a new phase.</p> Ivan V. Gushchin Copyright (c) 2022 Ivan V. Gushchin http://creativecommons.org/licenses/by/4.0 2022-12-06 2022-12-06 4 222 225 10.26565/2312-4334-2022-4-23