Determination of local material properties of OSB sample by coupling advanced imaging techniques and morphology-based FEM simulation

This is the publisher’s final pdf. The published article is copyrighted by Walter de Gruyter & Co. and can be found at: http://www.degruyter.com/.The goal was to determine local mechanical properties inside of oriented strand board (OSB) based on a realistic morphology-based finite element (FE) model and data acquired from a physical test performed on the same material. The spatial information and local grayscale intensity from CT-scans obtained from small OSB sample was transformed into a 2D regular morphology-based FE mesh with corresponding material properties. The model was then used to simulate the actual compression test performed on the specimen using simplified boundary conditions. The simulated strain fields from the model were compared with the actual strain field measured on the specimen surface during the compression test by means of a full-field optical method, named digital image correlation (DIC). Finally, the original set of material properties was adjusted by an iterative procedure to minimize the difference between the simulated and the measured strain data. The results show that the developed procedure is useful to find local material properties as well as for morphological modeling without the need of segmentation of the image data. The achieved results serve as a prerequisite for full 3D analyses of the complex materials

Optical second harmonic generation probe of two-dimensional ferroelectricity

Optical second harmonic generation (SHG) is used as a noninvasive probe of two-dimensional (2D) ferroelectricity in Langmuir-Blodgett (LB) films of copolymer vinylidene fluoride with trifluorethylene. The surface 2D ferroelectric-paraelectric phase transition in the topmost layer of LB films and a thickness independent (almost 2D) transition in the bulk of these films are observed in temperature studies of SHG.Comment: 9 pages, 2 figures, Optics Letters, in prin

An argon ion beam milling process for native AlOx\text{AlO}_\text{x} layers enabling coherent superconducting contacts

We present an argon ion beam milling process to remove the native oxide layer forming on aluminum thin films due to their exposure to atmosphere in between lithographic steps. Our cleaning process is readily integrable with conventional fabrication of Josephson junction quantum circuits. From measurements of the internal quality factors of superconducting microwave resonators with and without contacts, we place an upper bound on the residual resistance of an ion beam milled contact of 50$\,\mathrm{m}\Omega \cdot \mu \mathrm{m}^2$ at a frequency of 4.5 GHz. Resonators for which only $6\%$ of the total foot-print was exposed to the ion beam milling, in areas of low electric and high magnetic field, showed quality factors above $10^6$ in the single photon regime, and no degradation compared to single layer samples. We believe these results will enable the development of increasingly complex superconducting circuits for quantum information processing.Comment: 4 pages, 4 figures, supplementary materia

Electrical resistance of individual defects at a topological insulator surface

Three-dimensional topological insulators host surface states with linear dispersion, which manifest as a Dirac cone. Nanoscale transport measurements provide direct access to the transport properties of the Dirac cone in real space and allow the detailed investigation of charge carrier scattering. Here, we use scanning tunnelling potentiometry to analyse the resistance of different kinds of defects at the surface of a (Bi0.53Sb0.47)2Te3 topological insulator thin film. The largest localized voltage drop we find to be located at domain boundaries in the topological insulator film, with a resistivity about four times higher than that of a step edge. Furthermore, we resolve resistivity dipoles located around nanoscale voids in the sample surface. The influence of such defects on the resistance of the topological surface state is analysed by means of a resistor network model. The effect resulting from the voids is found to be small compared to the other defects

Социальные сети как актуальный инструмент формирования доверия к работе полиции

Актуальность данной темы обусловлена бурным развитием социальных сетей и деятельностью МВД, направленной на формирование доверия населения. Объект исследования – деятельность УМВД по формированию доверия к работе полиции. Предмет – роль социальных сетей в формировании доверия к работе полиции. Цель ВКР состоит в разработке и внедрении проектных рекомендаций по продвижению аккаунтов УМВД России по Томской области в социальных сетях. Методы: анализ и систематизация теоретических положений по проблеме исследования, сбор эмпирических данных – экспертное интервью, контент-анализ, синтез теоретических и эмпирических материалов. Сформулированы рекомендации по продвижению аккаунтов в социальных сетях ведомства. Первичное внедрение рекомендаций повысило охват аудитории и количество подписчиков.The relevance of this topic due to the rapid development of social media and activities of the MIA, aimed at the formation of public confidence. The object of study – the activity of the MIA on the formation of trust towards the police. Subject – the role of social media in shaping trust in the police. The purpose of the WRC is to develop and implement design recommendations for the promotion of accounts MIA of Russia across the Tomsk region on social media. Methods: the analysis of the theoretical positions on the research problem, the collection of empirical data – expert interviews, content analysis. Formulate recommendations for the promotion of accounts in social media Department. The primary implementation of the recommendations has increased the reach and number of subscribers

Quantum spin Hall edge states and interlayer coupling in twisted-bilayer WTe2_2

The quantum spin Hall (QSH) effect, characterized by topologically protected spin-polarized edge states, was recently demonstrated in monolayers of the transition metal dichalcogenide (TMD) WTe$_2$. However, the robustness of this topological protection remains largely unexplored in van der Waals heterostructures containing one or more layers of a QSH insulator. In this work, we use scanning tunneling microscopy and spectroscopy (STM/STS) to explore the topological nature of twisted bilayer (tBL) WTe$_2$ which is produce from folded monolayers, as well as, tear-and-stack fabrication. At the tBL bilayer edge, we observe the characteristic spectroscopic signature of the QSH edge state that is absent in topologically trivial as-grown bilayer. For small twist angles, a rectangular moir\'e pattern develops, which results in local modifications of the band structure. Using first principles calculations, we quantify the interactions in tBL WTe$_2$ and its topological edge states as function of interlayer distance and conclude that it is possible to tune the topology of WTe$_2$ bilayers via the twist angle as well as interlayer interactions

Технологические решения для строительства эксплуатационной наклонно-направленной скважины глубиной 3000 метров на Приобском нефтяном местрождении (ХМАО)

Данный диплом является технологическим строительным проектом эксплуатационной (ННП) скважины Приобского нефтегазового месторождения (Ханты-Мансийский автономный округ-ЮГРА). Цель бурения – вскрытие продуктивных пластов (2670-3000 м) Приобского месторождения. В дипломном проекте сделаны: технические расчеты ,технологические расчеты, экономические расчеты и необходимые данные. В выбранном проекте бурение скважины расчитываеться технический и экономический показатель характеризующий работы АО НФ “ССК” и сводный сметный расче, определяющий затраты на строительство наклоннонаправленой скважины. После расчитаных результатов приводиться составной план (ГТН) на строительство скважины.This diploma is a technological construction project operating in directional wells of Priobskoe oil and gas field (Khanty-Mansi Autonomous Okrug,YUGRA). The purpose of drilling – opening the productive layers (2670-3000 m) of the Priobsky Deposit. The thesis project is done: technical calculations ,process calculations, economic calculations, and required data. In the selected project drilling rasschityvaetsya technical and economic indicators characterizing the work of NF JSC “SSK” and the consolidated estimated calculation that determines the cost of construction of controlled directional wells. After the calculated results driven composite plan (GHP) for the construction of the well