Buckling behavior of multilayer cylindrical shells composed of functionally graded nanocomposite layers under lateral pressure in thermal environments

In this study, the stability behavior of multilayer cylindrical shells made of functionally graded nanocomposite layers (FG-NCLs) subjected to the lateral pressure in thermal environments is investigated. It is postulated that nanocomposite layers forming layered cylindrical shells are made of single-walled carbon nanotube (SWCNT)-reinforced polymers that have four types of profiles based on the uniform and linear distributions of mechanical properties. The material properties of SWCNTs are assumed to be dependent on location as well as temperature and are obtained from molecular dynamics simulations. The governing equations are derived as partial differential equations within shear deformation theory (SDT) and solved in a closed form, using the Galerkin procedure, to determine the lateral critical pressure (LCP) in thermal environments. The numerical representations relate to the buckling behavior of multilayer cylindrical shells made of functionally graded nanocomposite layers under the uniform lateral pressure for different CNT patterns and temperatures within SDT and Kirchhoff-Love theory (KLT)

Ab initio calculations of electronic band structure of CdMnS semimagnetic semiconductors

This work is devoted to theoretical investigations of Cd1-xMnxS semimagnetic semiconductors (SMSC). The purpose of this work was to calculate the electronic band structure of ideal and defective Cd1-xMnxS SMSC in both antiferromagnetic (AFM) and ferromagnetic (FM) phases. Ab initio, calculations are performed in the Atomistix Toolkit (ATK) program within the Density Functional Theory (DFT) and Local Spin Density Approximation (LSDA) on Double Zeta Double Polarized (DZDP) basis. We have used Hubbard U potential UMn = 3.59 eV for 3d states for Mn atoms. Supercells of 8 and 64 atoms were constructed. After the construction of Cd1-xMnxS (x = 6.25 %; 25 %) supercells and atom relaxation and optimization of the crystal structure were carried out. Electronic band structure and density of states were calculated, the total energy has been defined in antiferromagnetic (AFM) and ferromagnetic (FM) phases. Our calculations show that the band gap increases with the increase in Mn ion concentration. It has been established that Cd or S vacancy in the crystal structure leads to the change of band gap, Fermi level shifts towards the valence or conduction band

dReDBox: Materializing a full-stack rack-scale system prototype of a next-generation disaggregated datacenter

Current datacenters are based on server machines, whose mainboard and hardware components form the baseline, monolithic building block that the rest of the system software, middleware and application stack are built upon. This leads to the following limitations: (a) resource proportionality of a multi-tray system is bounded by the basic building block (mainboard), (b) resource allocation to processes or virtual machines (VMs) is bounded by the available resources within the boundary of the mainboard, leading to spare resource fragmentation and inefficiencies, and (c) upgrades must be applied to each and every server even when only a specific component needs to be upgraded. The dRedBox project (Disaggregated Recursive Datacentre-in-a-Box) addresses the above limitations, and proposes the next generation, low-power, across form-factor datacenters, departing from the paradigm of the mainboard-as-a-unit and enabling the creation of function-block-as-a-unit. Hardware-level disaggregation and software-defined wiring of resources is supported by a full-fledged Type-1 hypervisor that can execute commodity virtual machines, which communicate over a low-latency and high-throughput software-defined optical network. To evaluate its novel approach, dRedBox will demonstrate application execution in the domains of network functions virtualization, infrastructure analytics, and real-time video surveillance.This work has been supported in part by EU H2020 ICTproject dRedBox, contract #687632.Peer ReviewedPostprint (author's final draft

Legal rationale of biodiversity regulation as a basis of stable ecological policy

© 2018. ASERS Publishing. All rights reserved. The paper understands cross-border natural resources as a totality of characteristics of local ecological systems, which can act as regulators of human’s life space. Authors state that uniqueness of this phenomenon is defined by the fact that all natural resources act as a single system of planet scale. The problem distinguished in the paper is based on the fact that in the period of ecological systems and natural resources development a little attention is paid to cross-border management on the part of nations they belong to. The research subject is an indicator of stability and quality of management of cross-border natural resources in the aspect of their even existing and carrying out of their functions. Scientific novelty of the research is that it’s proved for the first time that each ecological system has s number of parameters, one of which shows how much it resistant to human impact. The system of providing biodiversity is one of such parameters. In the paper the legal characteristics of the issue are identified with the actual state of interstate cooperation and the opportunity of its expansion within the already existing interstate formation is determined. The example of such formation is European Union. The areas of further research can be defined as an expansion of specified cooperation of Asian and South American continent

Взаимосвязь маркеров эндотелиальной дисфункции при гнойном холангите у больных с хроническим гепатитом и без хронического гепатита на фоне обтурационной желтухи

Цель. Изучение взаимосвязи маркеров эндотелиальной дисфункции при гнойном холангите у больных с хроническим гепатитом и без хронического гепатита на фоне обтурационной желтухи, выявление его раннего перехода в цирроз печени и оптимизация тактики лечения в до- и послеоперационном периоде с оценкой показателей исследуемых лабораторных тестов. Материалы и методы. Исследование проведено в отношении 15 больных с гнойным холангитом, из них у 9 больных был хронический гепатит, у 6 больных хронического гепатита не было. Из 9 больных с хроническим гепатитом 4 больным противовирусную терапию не проводили, 5 - проводили. Результаты. Непосредственные результаты проведенного лечебно-диагностического исследования свидетельствуют о сходных проявлениях эндотелиальной дисфункции при гнойном холангите у больных с хроническим гепатитом и без хронического гепатита. Всем больным с гнойным холангитом выполняли декомпрессию желчных протоков, устраняли причины обтурации, проводили дезинтоксикационную терапию. По данным корреляционного анализа показателей функционального состояния эндотелия у больных с хроническим гепатитом, получавших противовирусную терапию, улучшение отметили на 10-е сут, через 1 мес оно было более выраженным, чем у больных, не получавших противовирусную терапию. У 6 больных с гнойным холангитом без хронического гепатита своевременное хирургическое, дезинтоксикационное лечение совместно с озонотерапией привело к улучшению показателей функционального состояния эндотелия на 10-е сут, через 1 мес они приблизились к норме. Выводы. Своевременное выявление эндотелиальной дисфункции при гнойном холангите у больных с хроническим гепатитом и без хронического гепатита способствует раннему прогнозированию его перехода в стадию цирроза печени и правильному выбору тактики лечения в до- и послеоперационном периоде. Подытожив полученные данные, можно сделать вывод о том, что при гнойном холангите у больных с хроническим гепатитом целесообразно проведение противовирусной терапии до и после операции

Effect of the C/N ratio modification on the corrosion behavior and performance of carbonitride coatings prepared by cathodic arc deposition

This study focuses on investigating carbonitride coatings, specifically CNTi-(Zr, ZrNb, and ZrSi), as promising candidates for enhancing the durability and efficiency of Ti6Al4V materials used in nuclear fusion technology. X-ray diffraction analysis identified distinct phases, including TiN, ZrN, ZrC, and TiC. The corrosion studies showed complete degradation of the TiN, ZrC, and ZrN phases in the TiZrCN coating after tests, while the TiC phase exhibited relative stability. The surface morphologies and elemental mapping analysis demonstrated the loss of homogeneity in element distribution after corrosion process. The addition of Si and Nb elements into TiZrCN significantly influenced the coatings' corrosion behavior, with breakaway corrosion observed in CNTi- (Zr and ZrSi) coatings and localized corrosion in CNTi-(ZrNb) coatings. Notably, the CNTi-(ZrSi) coating formed an oxide phase in the presence of NaCl, whereas the CNTi-(ZrNb) coating exhibited continuous resistance and a low corrosion rate. Irradiation was carried out for the generation of active isotopes, showing that no radioactive isotopes were formed in any of the investigated samples

Negative magneto-resistance of electron gas in a quantum well with parabolic potential

We have studied the electrical conductivity of the electron gas in parallel electric and magnetic fields directed along the plane of a parabolic quantum well (across the profile of the potential). We found a general expression for the electrical conductivity applicable for any magnitudes of the magnetic field and the degree of degeneration of the electron gas. A new mechanism of generation of the negative magnetoresistance has been revealed. It has been shown that in a parabolic quantum well with a non-degenerated electron gas the negative magnetoresistance results from spin splitting of the levels of the size quantization.Comment: 15 pages, 3 figure

Importance of the Caspian Countries for the European Union

When there is a lack of energy resources in the EU and it has to look for suppliers from other countries, Russia provides the world with most of the oil and gas. Diversification of energy resources is one of the objectives for the EU. The majority of international participants are interested in discovering the potential of the sea. However, the development of the region’s resources still faces many obstacles, such as lack of export pipelines, difficulties due to security of supply considerations, transit complications, political and legal considerations and market uncertainties. This study focuses on the countries of the former Soviet Union such as Uzbekistan, Kazakhstan and Turkmenistan in Central Asia, and Azerbaijan in Transcaucasia. One of the six priority areas of the EU in the energy infrastructure of - the Southern Energy Corridor (SEC), the purpose of which is to link the Caspian basin and potentially Middle Eastern gas to Europe. In the article, we analyzed the potential of the Caspian basin in terms of energy and its impact on the energy security of the European Union.Коли в ЄС виникає брак енергоресурсів, і він повинен шукати постачальників з інших країн, Росія забезпечує світ більшістю нафти та газу. Диверсифікація енергетичних ресурсів є однією з цілей для ЄС. Більшість міжнародних учасників зацікавлені у відкритті потенціалу моря. Проте для розвитку ресурсів регіону як і раніше виникають чимало перешкод, таких як відсутність експортних трубопроводів, труднощі з точки зору безпеки поставок, ускладнення транзиту, політичні та правові міркування та невизначеність ринку. Це дослідження присвячено країнам колишнього Радянського Союзу, таким як Узбекистан, Казахстан та Туркменістан в Центральній Азії, а також Азербайджану в Закавказзі. Одна з шести пріоритетних напрямків діяльності ЄС в енергетичній інфраструктурі - Південний енергетичний коридор (SEC), метою якої є з'єднання Каспійського басейну та потенційно ближнього східного газу до Європи. У статті ми проаналізували потенціал Каспійського басейну з точки зору енергії та її вплив на енергетичну безпеку Європейського Союзу.Когда в ЕС отсутствует дефицит энергоресурсов, и он должен искать поставщиков из других стран, Россия предоставляет миру большую часть нефти и газа. Диверсификация энергетических ресурсов является одной из целей для ЕС. Большинство международных участников заинтересованы в обнаружении потенциала моря. Однако развитие ресурсов региона по-прежнему сопряжено со многими препятствиями, такими как отсутствие экспортных трубопроводов, трудности, связанные с безопасностью соображений предложения, осложнениями транзита, политическими и юридическими соображениями и неопределенностью рынка. В этом исследовании основное внимание уделяется странам бывшего Советского Союза, таким как Узбекистан, Казахстан и Туркменистан в Центральной Азии, а также Азербайджан в Закавказье. Один из шести приоритетных направлений ЕС в энергетической инфраструктуре Южного энергетического коридора (SEC), целью которого является увязка Каспийского бассейна и потенциально ближневосточного газа с Европой. В статье мы проанализировали потенциал Каспийского бассейна с точки зрения энергетики и ее влияния на энергетическую безопасность Европейского Союза

The Conditions of Economic Efficiency and Competitiveness of Tourism Enterprises

The transition to a market system of management in Russia has put a lot of tourism enterprises in a predicament when the competition forces them to look for new ways of survival, use of competitive advantages and provision competitiveness of tourism enterprises and their service. As practice shows, many Russian tourism enterprises of are not ready for active competition, for most of them, the management of competitiveness cannot be referred to and does not act as a standalone system or subsystem in the management process. Despite having a large database and various methods of comprehensive analysis of enterprises (both in Russia and abroad), statistics of tourism enterprises do not currently offer their competitiveness assessment methods. The specific questions of measuring and competitiveness forecasting in terms of competitive market of various properties are no quite adequately developed, there are no well-defined method for competitiveness forecasting of various industrial classification enterprises. The competitiveness of tourism enterprises in the terms of competitive pressure increase is increasingly predetermined by internal and external competitive advantage o territorial subject. If the formation of internal competitive advantages depends on the competitive potential of tourism enterprise, the effectiveness of its management, the formation of external advantages - on the level of competitiveness of a country, region and industry. Keywords: competitiveness, economical efficiency, tourism JEL Classifications: L26, L82, L83, M3

Importance of the Caspian Countries for the European Union Energy Security

When there is a lack of energy resources in the EU and it has to look for suppliers from other countries, Russia provides the world with most of the oil and gas. Diversification of energy resources is one of the objectives for the EU. The majority of international participants are interested in discovering the potential of the sea. However, the development of the region's resources still faces many obstacles, such as lack of export pipelines, difficulties due to security of supply considerations, transit complications, political and legal considerations and market uncertainties. This study focuses on the countries of the former Soviet Union such as Uzbekistan, Kazakhstan and Turkmenistan in Central Asia, and Azerbaijan in Transcaucasia. One of the six priority areas of the EU in the energy infrastructure of - the Southern Energy Corridor (SEC), the purpose of which is to link the Caspian basin and potentially Middle Eastern gas to Europe. In the article, we analyzed the potential of the Caspian basin in terms of energy and its impact on the energy security of the European Union. Keywords: Caspian Sea, Central Asia, European Union, Southern Corridor, Pipeline, Energy Security JEL Classifications: F52, H55, H56