Vilnius Gediminas Technical University
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The Impact of Russia’s Import Embargo on the EU Countries’ Exports
No full textPolitical unrest inevitably has consequences for a national economy. International trade in a globalised world has great importance for countries. Unfortunately, due to various political events, countries apply some restrictions to each other. In 2014, Western countries imposed sanctions on trade with Russia, due to the annexation of Crimea. As a response, Russia announced an embargo on importing of some goods from European and North American countries, as well as Australia. The current study investigates the economic impact on EU countries due to the mentioned embargo. The EU countries were grouped according to the average for 1998–2018 exports of products to Russia using a cluster analysis. After the clustering, the gravity model was employed to develop the equations representing the international trade between each cluster and Russia. Although Russia declared an embargo on countries associated with the same group of goods, the economic impact on their economies was different. This study has a couple of limitations. The research reflects only the impact of the embargo on exports regardless of some possible indirect effects; the study assesses the export of all sectors due to limited data; and because the restrictions are applied only to the food sector, the research shows only relative changes in exports
VASMA Weighting: Survey-Based Criteria Weighting Methodology that Combines ENTROPY and WASPAS-SVNS to Reflect the Psychometric Features of the VAS Scales
Get PDFData symmetry and asymmetry might cause difficulties in various areas including criteria weighting approaches. Preference elicitation is an integral part of the multicriteria decision-making process. Weighting approaches differ in terms of accuracy, ease of use, complexity, and theoretical foundations. When the opinions of the wider audience are needed, electronic surveys with the matrix questions consisting of the visual analogue scales (VAS) might be employed as the easily understandable data collection tool. The novel criteria weighting technique VASMA weighting (VAS Matrix for the criteria weighting) is presented in this paper. It respects the psychometric features of the VAS scales and analyzes the uncertainties caused by the survey-based preference elicitation. VASMA weighting integrates WASPAS-SVNS for the determination of the subjective weights and Shannon entropy for the calculation of the objective weights. Numerical example analyzing the importance of the criteria that affect parents’ decisions regarding the choice of the kindergarten institution was performed as the practical application. Comparison of the VASMA weighting and the direct rating (DR) methodologies was done. It revealed that VASMA weighting is able to overcome the main disadvantages of the DR technique—the high biases of the collected data and the low variation of the criteria weights.This article belongs to the Special Issue Symmetric and Asymmetric Data in Solution Model
Determining the Impact of High Temperature Fire Conditions on Fibre Cement Boards Using Thermogravimetric Analysis
No full textWhen exposed to temperatures that are progressively and rapidly raised, large dimension fibre cement boards tend to crack. This occurrence is analysed and explained for a specific issue of asymmetric growth of a curvilinear crack in high temperatures. This phenomenon occurred while performing Single Burning Item (SBI) experiments at fire loads which are higher than those used in countries of the European Union, which better reflect fire events that may occur in high-rise buildings. In such conditions, fibre cement boards crack, allowing the fire to reach the thermal insulating material which then combusts, thereby helping to spread the conflagration to upper floors. This experiment investigated the temperatures at which fibre cement boards crack, and why. Thermal analysis methods and thermogravimetric experiments were conducted on the fibre boards, followed by X-ray phase analysis investigations. During this phase, X-ray structural analysis was performed while the fibre cement was exposed to temperatures of 1000 °C. The article also presents ongoing change results when heating only composite fibre-cement board materials; phase changes that take place in high temperatures are discussed.This article belongs to the Special Issue Materials Science: Synthesis, Structure, Propertie
Skirtingos žemėnaudos dirvožemių bendrosios anglies kiekio ir anglies dioksido emisijos tyrimai bei vertinimas
No full textSummary of doctoral dissertationSummary of doctoral dissertatio
Biochemical Pathways Leading to the Formation of Wyosine Derivatives in tRNA of Archaea
Get PDFTricyclic wyosine derivatives are present at position 37 in tRNAPhe of both eukaryotes and archaea. In eukaryotes, five different enzymes are needed to form a final product, wybutosine (yW). In archaea, 4-demethylwyosine (imG-14) is an intermediate for the formation of three different wyosine derivatives, yW-72, imG, and mimG. In this review, current knowledge regarding the archaeal enzymes involved in this process and their reaction mechanisms are summarized. The experiments aimed to elucidate missing steps in biosynthesis pathways leading to the formation of wyosine derivatives are suggested. In addition, the chemical synthesis pathways of archaeal wyosine nucleosides are discussed, and the scheme for the formation of yW-86 and yW-72 is proposed. Recent data demonstrating that wyosine derivatives are present in the other tRNA species than those specific for phenylalanine are discussed.This article belongs to the Collection Archaea: Diversity, Metabolism and Molecular BiologyJ.U. is supported by the Research Council of Lithuania (LMTLT) grant S-MIP-19-61
Bibliografijos ir PDF tvarkymas
No full textPristatymo tikslas – supažindinti mokslininkus su šiuolaikinėmis technologijomis, kad rankraščių rengimas būtų malonumas, o ne kančia.
Neretai tyrėjams, rengiant mokslinį darbą, kyla sunkumų analizuojant gausybę literatūros ir cituojant ją moksliniame darbe. Daug brangaus mokslininko laiko atima reikalingos informacijos paieška gausybėje PDF dokumentų, surinktų mokslinės veiklos laikotarpiu.
Taip pat moksliniame darbe itin svarbu tinkamai sutvarkyti cituojami šaltiniai, jų bibliografiniai aprašai. Tačiau kiekvieno leidėjo reikalavimai citavimui yra skirtingi, todėl mokslininkui pasirinkus kitą žurnalą citavimą reikia iš naujo sutvarkyti ranka...
Šių problemų sprendimui mokslininkai iš įvairių pasaulio šalių sukūrė programinius paketus kurie automatiškai sutvarko PDF dokumentų biblioteką ir cituojamos literatūros aprašus. Vilniaus Gedimino Technikos universiteto doktorantas Edgaras Timinskas išsamiai pristato vieną tokių programinių paketų – Mendeley
Tolydžiųjų asimetrinių reaktyviosios galios kompensatorių kūrimas
No full textThe aim of the performed research is development of reactive power compensators for the smooth and asymmetric reactive power compensation in the low voltage utility grid.
The cascaded inverter has been modified and adapted for the smooth compensation of reactive power. The topologies of the conventional and cascaded inverter-based reactive power compensators with the individual inverters for the every phase for the asymmetric compensation of reactive power have been proposed. The shunt-connected compensator for the smooth and asymmetric compensation of reactive power in the low voltage utility grid has been developed. The investigation of developed reactive power compensators was performed using simulation and experimentally.
The dissertation consists of an introduction, three chapters, general conclusions, references and the list of author's publications on the topic of the dissertation.
The research problem, the relevance of the work, the object of research are presented in the introductory chapter. The aim and objectives of the work, the research methodology, scientific novelty of the work, the practical significance of the work results, defended statements are presented as well. At the end of the introduction, the author's publications and conference papers on the topic of the dissertation and the structure of the dissertation are given.
The first chapter analyzes the reactive power compensation techniques and compensator types. The inverter-based reactive power compensators and shunt-connected reactive power compensators are analyzed. The conclusions are drawn out and the tasks of the dissertation are formulated.
The conventional and cascaded inverter based reactive power compensators are analyzed in the second chapter. The topologies of reactive power compensators with the individual ordinary inverters and cascaded inverters for the every phase for the asymmetric compensation of reactive power are proposed. The Matlab/Simulink models of compensators were created and investigation of compensators using simulation was performed.
In the third chapter the developed shunt-connected compensator for smooth asymmetric compensation of reactive power in low voltage utility grid is presented. The investigation of compensator was performed experimentally using developed experimental test bench.
The main results of the dissertation have been published in 4 scientific publications – 3 of them have been published in peer-reviewed scientific journals, 1 in conference proceedings. The results were presented at 5 scientific conferences.Doctoral dissertatio
Metai ir dienos. Vilniaus Gedimino technikos universitetas 2019 m.
Get PDFLeidinyje aprašomi Vilniaus Gedimino technikos universiteto 2019 metų svarbiausieji įvykiai,
mokslo ir studijų plėtotė, tarptautinis bendradarbiavimas, dalyvavimas tarptautinėse konferen-
cijose, senato ir rektorato priimti sprendimai ir kt. Pateikiama žinių apie universiteto padalinius:
fakultetus, katedras, centrus, institutus ir kt
Nature-Related Cognitive Schemas and Self-Reported Psychological Flourishing
No full textSome sustainability-related belief systems (or schemas in Cognitive Behavior Therapy) might result in shame, guilt, or denial if a person fails to meet the standards. The psychology of Harmonization relates sustainability to flourishing but not to human misery and delineates flourishing one’s own life. What nature-related cognitive schemas coexist with psychological flourishing? The purpose of this study was to identify the nature-related cognitive schemas that correlate to self-reported psychological flourishing. This paper provides some data on an overall survey (n = 722) that aimed at evaluating the cognitive schemas, strengths, and cognitive abilities of Lithuanian gymnasium students. We applied the Flourishing Scale (FS) of E. Diener alongside several measures to investigate nature-related cognitive/emotional/behavioral variables. The results revealed associations between different nature-related cognitive schemas (experiential, consumeristic, eco-protectionist, and valorist) and psychological flourishing, positive emotional reactions to nature, and spending time in nature. As this study demonstrates only positive or negative relationships among the examined variables, one of the implications for future research is identifying schemas as predictors of behavioral sustainability and creating an experimental or longitudinal design.This article belongs to the Special Issue Well-Being and Happiness for Harmonization of Natural and Cultural Resources: Cross-Cultural Pillars of SustainabilityThis research (data collection) was funded by the Lithuanian Business Support Agency, grant
number J05-LVPA-K-01-0066
Effect of Electrode Covering Composition on the Microstructure, Wear, and Economic Feasibility of Fe-C-Cr Manual Arc-Welded Hardfacings
No full textManual arc-welded hardfacings are widely used for the protection of new or the restoration of worn parts in agriculture, forestry, and mining applications. A study was conducted to investigate the effect of electrode covering composition on the microstructure, wear (low, average stress abrasion; erosion at 30, 50, and 80 m s−1), and economic feasibility of Fe–C–Cr manual arc-welded hardfacings. Hardfacings were produced with the carbon and chrome contents varied in the ranges of 0.87–2.95 and 1.3–33.2 wt.%, respectively. The major phases composing the microstructures of the hardfacings were austenite, perlite, ledeburite, and various carbides, including eutectic M7C3. Technical and economic analyses were performed to assess the economic feasibility of hardfacings and reference wear-resistant steel Hardox 400. A wear and economic feasibility map was created to specify various types and facilitate the selection of optimal hardfacings for specific conditions. The produced Fe–C–Cr coatings were the most effective in low-stress abrasive conditions (up to 7.8 times greater than Hardox 400) and quite effective in erosive conditions (up to 2.9 times greater than Hardox 400).This article belongs to the Special Issue Manufacturing and Surface Engineering IIThis research was supported (M. Antonov) by the Estonian Ministry of Higher Education and Research under Projects (M-ERA.NET MOBERA9 DURACER ETAG 18012, SS427, PRG643)