Magnetic and magneto-optical properties of CdS:Mn quantum dots in PVA matrix

We have studied the magnetic and magneto-optical properties of CdS:Mn quantum dots in polyvinyl alcohol matrix synthesized by co-precipitation method. The size of quantum dots was estimated by means of absorption spectroscopy. The results of measurements of magnetic susceptibility as a function of temperature and spectral dependence of the Faraday rotation of CdS:Mn quantum dots / polyvinyl alcohol composites are presented. In this work magnetic susceptibility was investigated by Faraday’s method at the temperatures of (78-300) K in magnetic fields of (0.05-0.8) T. The inverse magnetic susceptibility as a function of temperature follows a Curie Weiss law. Formation of ferromagnetic coupling between magnetic ions is supposed. Magneto-optical Faraday rotation has been investigated in the wavelength region (400-700) nm at temperature 300 K in a magnetic field up to 5 T. Sign of the Verdet constant is found to be negative

Approximation of 2π-periodic functions by Taylor—Abel—Poisson operators in the integral metric

We obtain direct and inverse approximation theorems of 2π-periodic functions by Taylor — Abel — Poisson operators in the integral metric.Отримано прямі та обернені теореми наближення 2π-періодичних функцій операторами Тейлора — Абеля — Пуассона в інтегральній метриці.Получены прямые и обратные теоремы приближения 2π-периодических функций операторами Тейлора — Абеля — Пуассона в интегральной метрике

Formation and transformation of II-VI semiconductor nanoparticles by laser radiation

Pulsed laser deposition has been applied for fabrication of Cd1-xMnxTe nanocrystals embedded in SiO2 matrix. By further thermal annealing an increase of average size of nanoparticles and narrowing of their size distribution was reached. Colloidal chemistry methods were used for preparing of Cd1-xMnxS nanoparticles. After UV irradiation of the colloidal solution with Cd1-xMnxS nanoparticles the average size and size distribution was changed owing size-selective photoetching mechanism. Results of optical and magneto-optical characterizations of the as-grown and the treated nanoparticle samples are described.The work was partially supported by the Ministry of Education and Science of Ukrain

New data on the fauna and bionomics of Lepidoptera of Crimea. Part II

Dahlica triquetrella (Hübner, 1813), Phyllonorycter cephalariae (Lhomme, 1934), Exaeretia thurneri (Rebel, 1940), Agonopterix lessini Buchner, 2017, Blastodacna vinolentella (Herrich-Schäffer, 1854), Bryotropha terrella ([Denis et Schiffermüller], 1775), Procapperia linariae (Chrétien, 1922), Synanthedon andrenaeformis (Laspeyres, 1801), Pediasia huebneri Błeszyński, 1954, Titanio ledereri (Staudinger, 1870), Phibalapteryx virgata (Hufnagel, 1767), Rhiza stenoptera (Boursin, 1970), Mythimna pudorina ([Denis et Schiffermüller], 1775) are recorded for Crimean Peninsula for the first time. New faunistic information for 4 species, Luquetia lobella ([Denis et Schiffermüller], 1775), Buszkoiana capnodactylus (Zeller, 1841), Procapperia maculatus (Constant, 1865), Millieria dolosalis (Heydenreich, 1851) known from Crimea by single and old records, is provided. New data on larval host plants for 9 species, Phyllonorycter cephalariae, Exaeretia thurneri, Agonopterix lessini, Monochroa uralensis Junnilainen, 2010, Buszkoiana capnodactylus, Procapperia linariae, Millieria dolosalis, Cucullia biornata Fischer von Waldheim, 1840, C. lactea (Fabricius, 1787), are given. The bionomics of immature stages of Exaeretia thurneri, Monochroa uralensis, Cucullia biornata, C. lactea is studied for the first tim

Evolution of CdS:Mn nanoparticle properties caused by pH of colloid solution and ultrasound irradiation

The effects of pH value and precursors concentrations in the growth solution as well as of ultrasound irradiation on the properties of CdS:Mn nanoparticles in PVA matrix are studied. Analysis of the photoluminescence spectra indicates that the increase of the pH value in the growth solution leads to the increase of the density of surface electron states that participate in radiative transitions and to the enlargement of CdS:Mn nanoparticles.We discuss a stabilization of the sizes of CdS:Mn nanoparticles at pH=6 and change of nanoparticle size with decreasing pH value at elevated concentrations of ions HS- . It is shown that in the ultrasound-treated samples the size of the particles does not depend on pH value. The effects of ultrasound result primarily from acoustic cavitation. It is demonstrated that the action of two external factors (the value of the medium pH and ultrasound treatment) on the characteristics of nanoparticles is correlated

Nucleation and growth kinetics of colloidal nanoparticles CdS:Mn in aqueous solution of polyvinyl alcohol

Colloidal undoped CdS and doped CdS:Mn nanoparticles were synthesized in the solution of polyvinyl alcohol polymer, and the process of nanoparticles growth was monitored by optical absorption measurements. The inclusion of Mn²⁺ impurity was checked by electron paramagnetic resonance measurements. It is shown that the core of CdS:Mn nanoparticle is undoped. The results obtained demonstrated that the rate of the band gap value decrease during nanoparticles growth is slower for the Mn-doped nanoparticles as compared to the undoped ones. This effect was ascribed to the inhibition of nanoparticles growth in the solution containing manganese salt. The model of the adsorptive doping of CdS NPs with manganese was proposed

A system for sorting radioactive waste of the Chernobyl exclusion zone

This work is extending the research started in 1998, which are directed on development of a Chernobyl origin radioactive waste sorting system. In this paper the principal scheme and possible engineering solutions of the system for sorting the waste placed in temporary localization dumps of the Chernobyl Exclusion Zone are described

Динамическое формирование персонализированного контента туристического мобильного приложения "Мультимедийный путеводитель"

Проведено поглиблений аналіз процесів інтелектуального динамічного індивідуального формування аудіо- та відеоконтенту для мобільного інформаційного супроводу користувача під час реалізації ним туристичної подорожі. Основною метою є розроблення методологічних підходів, які доцільно використати для проектування однієї із підсистем інноваційної інтелектуальної системи "МІАТ" (Мобільний інформаційний асистент туриста), яка забезпечуватиме формування та опрацювання аудіо- та відеоконтенту, потрібного для індивідуального інформаційно-технологічного супроводу користувача під час здійснення ним туристичних екскурсій, та узагальнене подання результатів проведеного авторами дослідження. Запропоновано використовувати туристичні путівники у форматі DAISY, як джерела мультимедійного контенту, що супроводжує подорож чи екскурсію.The in-depth analysis of the processes of intellectual dynamic individual formation of audio and video content to mobile information user's support during his tourist travel is conducted. The main goal is to develop methodological approaches that are appropriate to apply for designing one of the subsystems of innovative intelligent system "MIAT" (Mobile Information Assistant Tourists) which provides formation and processing of audio and video content required for individual information technology user support during his excursions. The presentation of the research conducted by the authors of the study is generalised. Some proposals to use the travel guide in DAISY format, as sources of multimedia content, something accompanies a trip or excursion, are presented.Проведен углубленный анализ процессов интеллектуального динамического индивидуального формирования аудио- и видеоконтента для мобильного информационного сопровождения пользователя при реализации им туристической поездки. Основной целью является разработка методологических подходов, которые целесообразно использовать для проектирования подсистемы инновационной интеллектуальной системы "МИАТ" (Мобильный информационный ассистент туриста), которая обеспечивает формирование и обработку аудио- и видеоконтента, необходимого для индивидуального информационно-технологического сопровождения пользователя при осуществлении ним туристических экскурсий, и обобщенное представление результатов проведенного авторами исследования. Предложено использование туристических путеводителей в формате DAISY, как источников мультимедийного контента, что сопровождает путешествие или экскурсию

The first record of Loxostege ayhanana Kemal et Koçak, 2017 (Lepidoptera: Crambidae) from the Europe, with notes on its bionomy

The first record of the micromoth Loxostege ayhanana Kemal et Koçak, 2017 from the Europe is presented, the larva, the moth with genitalia of both sexes are figured, and the larval foodplant and other details of biology are determined

New data on fauna and biology of Lepidoptera of Crimea

Nemophora prodigellus (Zeller, 1853), Cephimallota tunesiella (Zagulajev, 1966), Phyllonorycter issikii (Kumata, 1963), Lyonetia prunifoliella (Hübner, 1796), Agonopterix feruliphila (Millière, 1866), Agonopterix flurii Sonderegger, 2013, Depressaria floridella Mann, 1864, Scythris buszkoi Baran, 2004, Stathmopoda pedella (Linnaeus, 1761), Stagmatophora heydeniella (Fischer V. Röslerstamm, 1841), Atremaea lonchoptera Staudinger, 1871, Caryocolum marmorea (Haworth, 1828) Anacampsis scintillella (Fischer V. Röslerstamm, 1841), Eucosma aspidiscana (Hübner, 1817), Alucita cancellata (Meyrick, 1908), Phycita poteriella (Zeller, 1846), Algedonia terrealis (Treitschke, 1829), Chariaspilates formosaria (Eversmann, 1837), Cinglis humifusaria (Eversmann, 1837), Eucarta virgo (Treitschke, 1835) are recorded for Crimea Peninsula for the first time. New faunistic information for 8 species known from Crimea by single and old records is provided. New data on larval host plants and biology of immature stages for 19 species are given. The biology of Depressaria subalbipunctella Lvovsky, 1981, Depressaria floridella Mann, 1864, Dirhinosia interposita Bidzilya et Budashkin, 2015, Eugnosta lathoniana (Hübner, 1800), Aeschremon disparalis (Herrich-Schäffer, 1851), Evergestis nomadalis (Lederer, 1871), Eumannia lepraria (Rebel, 1909), Cleta perpusillaria (Eversmann, 1847), Haemerosia vassilininei A.  Bang-Haas, 1912, Gortyna cervago Eversmann, 1844, Cardepia hartigi Parenzan, 1981, Saragossa siccanorum (Staudinger, 1870) is studied for the first tim