Наукові публікації кафедри загальної та прикладної фізики

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Electrooptical and Nonlinear Optical Properties of Lyotropic Liquid Crystals Doped with Electrochromic Viologen
(Український фізичний журнал, 2012) Bordyuh, Hanna; Polishchuk, Arkadiy
This work presents the results of experimental studies of the electrooptical and nonlinear optical properties of lyotropic ionic liquid crystals (LILC) with soluted electrochromic admixtures of viologens. It is established that the Smectic A ordering of the LILC of potassium caprylate is not disrupted by the introduction of viologens. Moreover, LILC-viologen composites obtain electrochromic properties inherent to viologens, which produce colored radical cations and dimers, while reducing. The presence of radical cations and dimmers is fixed by the optical absorption spectra. It is found that, under the action of an electric field, the LILC-viologen samples form a bilayer structure consisting of a liquid crystal layer and an absorptive layer of viologen redox products (radical cations and dimers). A dynamic grating recording is realized and studied in bilayer LILC-viologen cells. It is determined that the recording takes place in the colored layer of viologen redox products. A possible mechanism of grating recording in LILC-viologen cells is proposed.
Mechanism of dimerization of viologens in liquid crystalline medium
(Ukr. J. Phys. 2017. Vol. 62, No. 4 294-298, 2017) Bordyuh, Hanna
This work presents the analysis of experimental data on electrooptical properties of viologens incorporated into the liquid crystalline medium. These data along with theoretical considerations allow specifying the mechanism, which leads to the double color change in the liquid crystal – viologen samples stipulated by the application of increasing voltage values. Specifically, it is proved that the first color change takes place due to the one-electron reduction of viologen molecules, and the second color change is caused by the dimerization between viologen molecules, which were fully reduced under the action of a voltage applied, and initial viologen molecules.
Структурні та електрооптичні властивості електрохромних рідкокристалічних композитів
(Національний Авіаційний Університет, 2012) Бордюг, Ганна Борисівна; Поліщук, Аркадій Петрович
Наведено результати структурних та електрооптичних досліджень новостворених композитів на основі ліотропних рідких кристалів каприлату калію та віологенів. Визначено наявність у дослі-джуваних зразках смектичного впорядкування. Описано його основні параметри. Показано, що електрохромні властивості віологенів зберігаються і при розчиненні в рідкокристалічній матриці, що проявляється в забарвленні зразків під дією зовнішнього електричного поля і підтверджується оптичними спектрами поглинання. Проаналізовано процеси, які проходять у композитах ліотропні рідкі кристали – віологен у разі прикладання електричного поля.
Fast Nolinear Optical Mechanisms in Bi-Layered Cells Composed by Lyotropic Ionic Liquid Crystals with Dye and Viologen Films
(Taylor & Francis Group, LLC, Mol. Cryst. Liq. Cryst., Vol. 508, pp. 296[658]–308[670], 2009, 2009) Bordyuh, Hanna
Mechanisms of the fast optical nonlinearity are studied in two types of cells based on lyotropic ionic liquid crystals (LILC) of metal alkanoates. They are (I) bi-layer cell, which consists of a thin dye film covered by LILC, and (II) LILC with electrochromic impurity (viologen). Applying dc electric voltage to the cell II leads to adsorption of viologen redox products with formation of a thin nanosized layer on the cathode. The dynamic holographic technique with pulsed laser radiation of the nanosecond duration was used to investigate nonlinear optical properties in both types of cells. The mechanism of photoconversion of viologen redox products under strong laser radiation is proposed to explain grating recording in the cell II.
Liquid crystal materials with regulated optical properties
(Національний Авіаційний Університет, 2013) Bordyuh, Hanna
In this work we present the results of structural and electrooptical investigations of the new-created composites based on lyotropic liquid crystals (LLC) of potassium caprylate and viologens. Provided structural analysis showed the presence of a Smectic ordering in the investigated samples and allowed to determine its main parameters. It was shown that the electrochromic properties of viologens are preserved after their solution in the liquid-crystalline matrix. They reveal themselves as a coloration of the samples under applying of an electric field and are proved by the optical absorption spectra. Also we analyzed the processes taking place in LLC-viologen composites in the case of an electric field applying.
Conductivity of composites of thermotropic ionic liquid crystals
(Electronics and Control Systems 2015. N 2(44): 29-32, 2015) Gridyakina, Alexandra
This work presents the studies of the transport properties of samples of oriented binary composite of cobalt decanoate with lead decanoate. Found that samples of the mixture at the temperature range of liquid crystal existence are weak electrolytes, which have anisotropy of bulk conductivity caused by the ordering of molecules. The values of mobility and charge concentration were estimated.
Electric properties of ionic thermotropic liquid crystals
(Український фізичний журнал., 2016. Т. 61, № 6, 2016) Gridyakina, Alexandra
This work presents the results of studies of the electric properties of samples of oriented ionic thermotropic liquid crystals (ITLC) of cobalt decanoate, lead decanoate, and their binary mixture. It is found that all studied samples in the temperature range, where a liquid crystal exists, are weak electrolytes. All investigated compounds are characterized by an anisotropy of bulk conductivity caused by the ordering of molecules. The values of electric conductivity, activation energy, charge mobility, and concentration are estimated.
Cubic Susceptibility and Hyper-polarizability of the Lyotropic Liquid Crystal−Viologen System
(Ukr. J. Phys. 2008, Vol. 53, N 12, p.1167-1173, 2008) Bordyuh, Hanna; Polishchuk, Arkadiy
Nonlinear optical properties of the “lyotropic liquid crystal–viologen” system are investigated. The system shows electrochromism under the action of an external electric field. For the colored samples, the recording of dynamic holographic gratings is obtained, by using the pulse laser method. The main characteristics of a recording on such samples are studied. On their base in view of the electrooptical properties of the system, the mechanism of the recording of gratings is proposed. The recording is realized due to a change in the polarizability of the π-electron system of viologen derivatives under the action of an intense laser radiation. The main nonlinear optical parameters (n2, χ(3), γ) of the system under study are determined.
Mechanism of dimerization of viologens in liquid crystalline medium
(Національний Авіаційний Університет, 2015) Bordyuh, Hanna
This work presents the analysis of experimental data on optical properties of viologens introduced to the liquid crystalline medium stipulated by the application of increasing voltage values. These data along with quantum mechanical theory allowed to specify the mechanism of dimerization of violoden molecules which leads to the colour change of the liquid crystal-viologen sample. Specifically, the dimerization of viologen molecules in liquid crystalline medium occurs due to interaction between viologen molecules, which were fully reduced under the action a voltage applied, and initial viologen molecules.
Holographic grating recording in “lyotropic liquid crystal – viologen” system
(Національний Авіаційний Університет, 2013) Bordyuh, Hanna; Polishchuk, Arkadiy
This work presents the results of nonlinear optical experiment run on the samples of lyotropic liquid crystal (LLC) with viologen admixtures. During the experiment we obtained dynamic grating recording on bilayered LLC-viologen samples and determined main characteristics of recoded gratings. It was found out that the recording takes place in a thin near-cathode coloured viologen layer. The analysis of kinetics of thermal gratings erasing showed that contribution of a thermal nonlinearity into general diffraction efficiency is negligible small. The last fact is connected with a separation of LLC-viologen samples under the action of an electric field and heat sink into the liquid crystal layer.
Structure and Intermolecular Interactions in Ionic Liquid Crystals Doped with Electrochromic Viologen
(Russian Journal of Physical Chemistry, Vol. 79, Suppl. 1, 2005, pp. S66–S70, 2005) Bordyuh, Hanna; Polishchuk, Arkadiy
The results of an investigation of structural and electrooptical properties of potassium caprylate lyotropic liquid crystals (LCs) doped with electrochromic viologen are presented. The samples are colored when an electric field is applied. The color deepens with the voltage applied, and relevant features appear in electronic absorption spectra. Two stages may be recognized in the processes that occur in a sample in the field. The first stage (at 2–2.5 V) involves the formation of radical cations (RCs) from viologen molecules, which makes the samples blue (two absorption bands appear at wavelengths of 395 and 610 nm in optical spectra). At the second stage (at 3.5–4 V), the radical cations are dimerized, and the sample becomes red (the spectra show bands in the region of 365 and 520 nm). Absorption in a lyotropic LC increases with the viologen concentration increasing from 1 to 2 to 4%. Small-angle X-ray scattering was measured on unoriented samples of pure potassium caprylate with thicknesses ranging from 30 μm to 1 mm. In all samples, a smectic order was observed in lyotropic ionic LC (LILC). From the X-ray scattering data, the bilayer thickness and the smectic correlation length were computed. It was inferred that viologen molecules, when present in low concentrations (1–4%), are organically incorporated into the matrix without spoiling the layer order intrinsic to the matrix.
Nonlinear optical response of smectic structure glasses based on cobalt alkanoates
(IEEE, 2010, 2010) Gridyakina, Alexandra
Nonlinear-optical response of metal-alkanoates anisotropic glasses based on cobalt-alkanoate was studied using method of the dynamic holography. Fundamental optical (refractive index and absorption coefficient) and nonlinear-optical (nonlinear susceptibilities and polarizabilities) parameters of the mesomorphic glasses based on cobalt-alkanoates can be tuned via varying chain length anion (interlayer distance of homologous lines) and\or by changing of the cation composition (exploiting binary or ternary systems).
Dynamic grating recording in lyotropic ionic smectics of metal alkanoates doped with electrochromic impurities
(Elsevier, Optical Materials 31 (2009) 1109–1114, 2009) Bordyuh, Hanna; Polishchuk, Arkadiy
In this work, we investigated nonlinear-optical properties in lyotropic ionic liquid crystals (LILC) of potassium caprilate doped with electrochromic impurities (viologens). It is known that after applying a direct electric field to the LILC-viologen cells colouration of samples is observed [1]. Dynamic grating recording under the action of nanosecond pulse laser radiation was obtained for the coloured samples. We analyzed the origin of the optical nonlinearity in the investigated materials taking into account their electrochemical and electrooptical properties. To explain grating recording in LILC doped with viologens, we proposed the mechanism of photoconversion in viologen molecules.
Mechanism of optical nonlinearity in “Lyotropic Liquid Crystal-Viologen” system
(2014) Bordyuh, Hanna; Polishchuk, Arkadiy
In the present work we analyze the characteristics of holographic grating recording and consider a mechanism of optical nonlinearity in the lyotropic liquid crystal (LLC) —viologen samples. Taking into account structural and electrooptical properties of the admixture molecules it is possible to suggest that the recording is realized due to the change of polarizability of -electron system of coloured viologen derivatives under the action of laser radiation. The main nonlinear optical parameters such as nonlinear refraction coefficient, cubic nonlinear susceptibility, and hyperpolarizability were calculated.
Діагностика та моніторинг теплоенергетичного обладнання на базі Smart Grid
(Архивариус, 2020-01-20) Свердлова, Анастасия Дмитриевна
Розглянуті можливості використання «розумних мереж» в системах моніторингу та діагностики теплоенергетичного обладнання. Проаналізовано причини несправностей і аварійних ситуацій обладнання генерації, транспортування та споживання теплової енергії. Розглянуто основні методи неруйнівного контролю застосовні для діагностики технічних вузлів, і інформативні сигнали, які виникають в процесі експлуатації енергетичного обладнання. Запропоновано структури функціонування теплоенергетичного обладнання для застосування технології Smart Grid в системах моніторингу та діагностування відповідних ієрархічних рівнів. Досліджено основні переваги енергетичних мереж на базі технології Smart Grid перед традиційними мережами.
Особенности mesh-сети для диагностирования энергетического оборудования на базе мультисенсорных систем
(Научный журнал "Архивариус", 2019-06-20) Свердлова, Анастасия Дмитриевна
Разработан метод диагностики теплотехнического оборудования теплоэнергетических объектов, основанный на применении «умных сетей» Smart Grid. Создана структура многоуровневой системы диагностики теплотехнического оборудования, что характеризуется возможностью использования большого количества модульных сенсоров (первичных преобразователей). Разработан аппаратно-программный комплекс для реализации алгоритмов статистической обработки информационных сигналов, создании эталонных диагностических функций по результатам измерений с использованием методов неразрушающего контроля, принятия диагностических решений, оценки остаточного ресурса и планирования отказов на базе концепции «больших данных» Big Data и «облачных» технологий.
Создание и эволюция Вселенной От Библии к науке
(LAP LAMBERT Academic Publishing. - 2018. – 625 p., 2018) Кондратенко, Петро Олексійович
Монография посвящена освещению основных принципов и законов Библии, из которых следует истинная информация о нашей Вселенной, значительно превышающая понимание современной науки. Законы единства и подобия, подробно изложенные в Библии, позволяют построить истинную картину Вселенной. Дело творческих людей – познакомиться с этими Законами и принципами, осознать их и использовать для познания Вселенной в целом и каждого ее участка в частности. На основании Законов Библии автор разработал новую модель рождения и эволюции Вселенной, в которой выполняются все известные законы физики. Модель позволила описать механизмы фундаментальных взаимодействий в мире элементарных частиц. Показано, что Супер-Вселенная представлена расслоенным пространством и состоит из четырех Миров: одномерного Мира Поля-времени, двумерного Мира дионов (частиц Планка), трехмерного Мира кварков и четырехмерного (3 + 1) Мира - нашей Вселенной. В монографии изложен механизм рождения атомных ядер, планетарных систем, кратных звездных систем и галактик, а также приводится решение ряда других важных научных вопросов.
Контроль процесса сжигания топлива в котлоагрегатах малой и средней мощности с использованием сенсоров кислорода
(Научные известия на НТСМ, 2017-06) Запорожец, Артур Александрович; Бабак, Виталий Павлович; Пономаренко, Александр Васильевич
Boiler’s technical condition which are using in communal and industrial power engineering is being analyzed. The method of improving the accuracy of the excess air ratio which based on present level of oxygen’s concentration in the air is offered. The structure of fuel combustion monitoring and directing system is developed. The structure based on fluent speed regulation of ventilator ‘s engine on signals of oxygen sensors in the exhaust gases are elaborated. The results of experimental research of developed system based on boiler NIISTU-5 are showed.
Фізика Високозбуджених Станів Барвників
(2018) Кондратенко, Петро Олексійович
Про енергетичні потоки у Всесвіті
(2018) Кондратенко, Петро Олексійович

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