Analysis of transient action influence in power transformer

This article is focused on the theory of unacceptable effect on transformer winding, mainly the overvoltages and the mechanical forces. In the next part of the article is described the measurement of selfdischarging voltage frequency dependence on transformer. The second measurement shows one of the possible type of SFRA method. The measurement results lead us only to the conclusion that some changes of the winding condition have occurred

Modelování interakce proteinů a peptidů s kovovými ionty

Modelling of interactions of proteins and peptides with metal ions Ondrej Gutten - Diploma thesis Keywords: Metalloproteins, metal ion selectivity, in silico prediction Abstract: An approach for in silico prediction and estimation of selectivity properties of metal-binding peptides is suggested. An in-depth analysis is performed to disclose the justifiability and limitations of this approach. The study is divided into three parts. First part investigates the soundness of two quantum chemical methods (MP2 and DFT) for their use in the set-up quest. The testing includes comparison with CCSD(T), effect of basis selection, performance of the two methods in geometry optimizations and effect of implicit solvent model. Second part foreshadows the approach of searching for a metal selective peptide by thoroughly investigating the ability of simple representative systems, derived from their metalloprotein templates, to retain the property of interest. Final part describes the initial step of extensive combinatorial approach towards examination of vast number of simple systems that represent metal-binding sites, and which are to be used for prediction of metal-selectivity through exploitation of the described approach and, ultimately, to the de novo design of metalloproteins with desired properties.Modelování interakce proteinů a peptidů s kovovými ionty. Ondrej Gutten - Diplomová práce Klíčová slova: Metaloproteiny, selektivita pro ionty kovů, in silico predikce Abstrakt: Byla navržena metoda pro in silico predikci a odhad schopnosti vybraných peptidů selektivně vázat ionty kovů. Dále byly důkladně otestovány použitelnost a omezení navržené metody. Studie je rozdělena do tří částí. První část se zabývá použitelností dvou kvantově- chemických metod (DFT, MP2) pro navržený přístup. Testování zahrnuje porovnání s referenčními výsledky získanými metodou CCSD(T), analýzu vlivu použité báze atomových orbitalů, porovnání obou metod při optimalizaci geometrie a analýzu použitého modelu reprezentujícího vodní prostředí. Ve druhé části jsou porovnávány výsledky predikce selektivity vazby iontů kovů v modelových peptidech a v jednoduchých systémech z nich odvozených. Poslední část diplomové práce popisuje první krok v rozsáhlé snaze prozkoumat obrovské množství jednoduchých modelových systémů, která povede k návrhu metaloproteinů s definovanými vlastnostmi.Department of BiochemistryKatedra biochemieFaculty of SciencePřírodovědecká fakult

Тепловое измерение и его применение для диагностики масляных трансформаторов распределительных сетей

In the first part of the paper the theory of infrared radiation and the use of nondestructive measurement of electrical devices by means of thermovision are under analysis. In the second part of paper basic principles and application of non-contact temperature measurement are examined. In the third part of paper thermal processes in distribution oil transformer – temperature in dependence on height of oil transformer and temperature distribution in sectional plan of oil transformer – are considered. In the fourth part of paper, by means of the experimental measurements and subsequent analysis, practical thermal imaging and contact thermal measurements by optical detectors for the diagnosis of distribution oil transformers in the field of mechanical strength of windings are shown. In this paper, we wanted to show out the possibility of using thermal measurements in this field of analysis and detection of quality of winding for distribution oil transformer. It is possible to use these methods to localize places of faults, and they are also applicable for the diagnosis and detection of disorders of the quality of materials and other anomalies during operation of the equipment. By means of the experimental measurements followed by diagnostic analysis the practical use of thermovision and optical sensors for diagnostics of power oil transformers in field mechanical strength and quality of winding is demonstrated.Cтатья посвящена анализу теории инфракрасного излучения и применения неразрушающего контроля с помощью электрических приборов и тепловизионного оборудования. Изложены основные принципы использования бесконтактного измерения температуры. Проанализированы тепловые процессы в силовом масляном трансформаторе: температура в зависимости от его высоты и распределение температуры в секционном плане масляного трансформатора. Рассмотрены экспериментальные тепловизионное и контактные тепловые измерения оптическими детекторами для диагностики механической прочности обмоток силовых масляных трансформаторов. Также показана возможность использования тепловых измерений для анализа и определения качества обмотки масляного трансформатора. Эти методы позволяют локализовать места неисправностей и могут использоваться для диагностики и выявления нарушений качества материалов и других аномалий в ходе эксплуатации оборудования. Путем экспериментальных измерений с последующим анализом определено практическое применение тепловизионных и оптических датчиков для диагностики силовых масляных трансформаторов в части механической прочности и качества обмоток

Диагностика частотной области изоляции трансформатора

The first part of paper deals with the base information about diagnostics of power transformers. In this part are presented differently insulating methods, for example method of recovery voltage method, method of polarization and depolarization currents and chromatographic analysis. The second part of paper deals use of method of frequency domain spectroscopy for oil power transformers. This method is used in analysis insulating condition of power transformer with system of oil-paper. It was found, that the results of these tests are highly impacted by the operating temperature during the experimental measurement. Moisture and conductivity between insulating paper and oil in an insulating system are highly dependent from temperature. In the other part, the paper presents experimental results of the frequency diagnostic measurement for a real single-phase traction transformer 110/27 kV at different operating temperatures and states (with oil and without). Finally in the last part, the paper presents comparing frequency insulating measurements among several the same single-phase transformers 110/27 kV

Диагностика частотной области изоляции трансформатора

The first part of paper deals with the base information about diagnostics of power transformers. In this part are presented differently insulating methods, for example method of recovery voltage method, method of polarization and depolarization currents and chromatographic analysis.The second part of paper deals use of method of frequency domain spectroscopy for oil power transformers. This method is used in analysis insulating condition of power transformer with system of oil-paper. It was found, that the results of these tests are highly impacted by the operating temperature during the experimental measurement. Moisture and conductivity between insulating paper and oil in an insulating system are highly dependent from temperature.In the other part, the paper presents experimental results of the frequency diagnostic measurement for a real single-phase traction transformer 110/27 kV at different operating temperatures and states (with oil and without).Finally in the last part, the paper presents comparing frequency insulating measurements among several the same single-phase transformers 110/27 kV.В первой части статьи приведены базовые сведения о методах диагностики силовых трансформаторов. В этой части представлены различные методы исследования изоляции, в частности, метод восстановления напряжения, метод токов поляризации и деполяризации и метод хроматографического анализа.Во второй части статьи рассмотрено использование метода частотной спектроскопии для масляных силовых трансформаторов. Данный метод использован для анализа состояния изоляции силовых трансформаторов с системой масло-бумага. Определено, что на результаты такого анализа значительное влияние оказывает температура окружающей среды при проведении измерений. Влажность и проводимость между бумажной изоляцией и маслом существенно зависят от температуры.Далее в статье приведены экспериментальные результаты диагностических частотных измерений для однофазного тягового трансформатора 110/27 кВ при различных значениях температуры окружающей среды и в различных состояниях (с маслом и без масла).В завершающей части статьи выполнено сравнение результатов частотных измерений нескольких однотипных однофазных трансформаторов 110/27 кВ

The synthesis and unexpected solution chemistry of thermochromic carborane-containing osmium half-sandwich complexes

YesThe functionalisation of the 16-electron complex [Os(η6-p-cymene)(1,2-dicarba-closo-dodecarborane- 1,2-dithiolato)] (1) with a series of Lewis bases to give the 18-electron complexes of general formula [Os(η6-p-cymene)(1,2-dicarba-closo-dodecarborane-1,2-dithiolato)(L)] (L = pyridine (2), 4-dimethylaminopyridine (3), 4-cyanopyridine (4), 4-methoxypyridine (5), pyrazine (6), pyridazine (7), 4,4’-bipyridine (8) and triphenylphosphine (9)) is reported. All 18-electron complexes are in equilibrium in solution with the 16-electron precursor, and thermochromic properties are observed in some cases (2, 3, 5, 8, and 9). The binding constants and Gibbs free energies of the equilibria are determined using UV-visible titrations and their stabilities investigated. Synthetic routes for forcing the formation of the 18-electron species are proposed, and analytical methods to characterise the equilibria are described.We thank the Leverhulme Trust (Early Career Fellowship No. ECF-2013-414 to NPEB), and the University of Warwick (Grant No. RD14102 to NPEB)

Pseudo electron-deficient organometallics: limited reactivity towards electron-donating ligands

YesHalf-sandwich metal complexes are of considerable interest in medicine, material, and nanomaterial chemistry. The design of libraries of such complexes with particular reactivity and properties is therefore a major quest. Here, we report the unique and peculiar reactivity of eight apparently 16-electron half-sandwich metal (ruthenium, osmium, rhodium, and iridium) complexes based on benzene-1,2-dithiolato and 3,6-dichlorobenzene-1,2-dithiolato chelating ligands. These electron-deficient complexes do not react with electron-donor pyridine derivatives, even with the strong σ-donor 4-dimethylaminopyridine (DMAP) ligand. The Ru, Rh, and Ir complexes accept electrons from the triphenylphosphine ligand (σ-donor, π-acceptor), whilst the Os complexes were found to be the first examples of non-electron-acceptor electron-deficient metal complexes. We rationalized these unique properties by a combination of experimental techniques and DFT/TDFT calculations. The synthetic versatility offered by this family of complexes, the low reactivity at the metal center, and the facile functionalization of the non-innocent benzene ligands is expected to allow the synthesis of libraries of pseudo electron-deficient half-sandwich complexes with unusual properties for a large range of applications

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