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Biblioteka informuoja, 2024 Nr. 48 (692)
No full textNaujai į Web of Science ir Scopus įtrauktų Vilnius Gedimino technikos darbuotojų publikacijų sąrašai ir kitos bibliotekos aktualijos.48 (692)202
Metai ir dienos. Vilniaus Gedimino technikos universitetas 2023 m.
No full textLeidinyje aprašomi Vilniaus Gedimino technikos universiteto 2023 metų svarbiausieji įvykiai, mokslo ir studijų plėtotė, tarptautinis bendradarbiavimas, dalyvavimas tarptautinėse konferencijose, senato ir rektorato priimti sprendimai ir kt. Taip pat pateikiama žinių apie universiteto padalinius: fakultetus, katedras, centrus, institutus ir kt.
Leidinys skirtas plačiajai visuomenei
Metalo ir biomedžiagų nanokompozitų formavimas ir taikymas imuniniuose jutikliuose
No full textImmunosensors are renowned for their high sensitivity and specificity, making them commonly used in diagnostics. Immunosensors are utilized to identify cancerous conditions, conduct histological studies, and as a tool to help control the spread of viral diseases. However, creating quantitative immunological sensors often involves challenges such as the denaturation of the biological recognition element or label, insufficient signal strength, or the need for expensive equipment to convert the signal into a measurable one. The dissertation focuses on the development of a quantitative electrochemical immunosensor by creating a new method to detect labeled antibodies and replacing traditional labels with denaturation-resistant nanoparticles.
The dissertation aims to create a prototype of a quantitative electrochemical immunosensor using a metal-biomaterial composite as the recognition element and scanning impedance microscopy for signal conversion.
The introduction presents the problem formulation, the object, and the relevance of the dissertation. It describes the research methodology, scientific novelty, defending statements, and the structure of the dissertation.
The first chapter provides an overview of immunosensors. It discusses biosensors and focuses on electrochemical immunosensors, their history, and types. The use of nanomaterials, i.e., gold, platinum, reduced graphene, and conductive polymers, in immunosensors is described. The working principles of scanning electrochemical microscopy and electrochemical impedance spectroscopy, as well as their application in immunological sensors, are analyzed. Surface characterization methods are also briefly discussed.
The second chapter reviews the methods and materials used, solution preparation, sample immobilization, and electrode modification protocols. The construction of electrochemical cells and the parameters used are briefly described. This chapter also outlines the mathematical models used to determine reaction kinetics and surface parameters.
The third chapter presents the results of experimental studies on the immunological sensor. It details the advantages and disadvantages of scanning electrochemical impedance microscopy, modifications to ultramicroelectrodes to address high resistance encountered, and the evaluation of a prototype quantitative immunosensor based on gold nanoparticle-labeled antibodies and scanning electrochemical impedance microscopy as the signal converter.
The dissertation’s results have been published in seven scientific articles in journals indexed in the Clarivate Analytics Web of Science database. The dissertation topic has been presented at eleven international conferences.Imuniniai jutikliai garsėja dideliu jautrumu ir specifiškumu, todėl dažnai yra naudojami diagnostikoje. Imuninius jutiklius naudojami vėžiniams susirgimams nustatyti, histologiniams tyrimams atlikti ir kaip priemonę, leidžiančią kontroliuoti virusinių ligų plitimą. Tačiau kuriant kiekybinius imuninius jutiklius dažnai susiduriama su biologinio atpažinimo elemento ar žymens denatūravimu, nepakankamu signalo stiprumu norint signalą paversti išmatuojamu. Disertacijoje pagrindinis dėmesys yra skiriamas kiekybinio elektrocheminio imuninio jutiklio kūrimui. Taikant naują metodą aptikti žymėtą antikūną bei tradicinius žymenis pakeičiant atspariais denatūravimui, grįstus nanodalelėmis.
Šios disertacijos tikslas yra sukurti kiekybinio elektrocheminio imuninio jutiklio prototipą taikant metalo ir biomedžiagos kompozitą kaip atpažinimo elementą ir skenuojamąsias impedanso mikroskopijas signalui keisti.
Įvade pristatoma darbo problematika, tyrimo objektas, disertacijos aktualumas ir svarba, aprašoma tyrimo metodika, mokslinis naujumas, ginamieji teiginiai ir disertacijos struktūra.
Pirmajame skyriuje pateikiama imuninių jutiklių apžvalga. Aptariami biologiniai jutikliai ir koncertuojamasi į elektrocheminius imuninius jutiklius, jų istoriją ir tipus. Aprašomas nanomedžiagų: aukso, platinos, redukuoto grafeno ir laidžių polimerų panaudojimas imuniniuose jutikliuose. Analizuojami skenuojamosios elektrocheminės mikroskopijos ir elektrocheminio impedanso spektroskopijos veikimo principai bei jų taikymas imuniniuose jutikliuose. Trumpai aprašomi paviršiaus charakterizavimo metodai.
Antrajame skyriuje apžvelgiami taikyti metodai ir naudotos medžiagos, tirpalų paruošimo bei mėginio imobilizavimo ir elektrodo modifikavimo protokolai. Pateikiama elektrocheminių celių konstrukcija ir trumpai aprašomi naudoti parametrai. Šiame skyriuje taip pat aprašomi matematiniai modeliai, taikyti reakcijų kinetikai ir paviršiaus parametrams nustatyti.
Trečiajame skyriuje pateikiami imuninio jutiklio eksperimentinių tyrimų, kurių metu buvo nustatyta skenuojamosios elektrocheminės impedanso mikroskopijos privalumai ir trūkumai, rezultatai, modifikuoti ultramikroelektrodai, kuriais siekiama išspręsti registruojamą didelės varžos problemą. Taip pat įvertintas prototipinis kiekybinis imuninis jutiklis, paremtas aukso nanodalele žymėtais antikūnais ir skenuojamąja elektrocheminio impedanso mikroskopija kaip signalo keitikliu.
Disertacijos rezultatai pristatyti septyniuose moksliniuose straipsniuose, publikuotuose Clarivate Analytics Web of Science duomenų bazėje esančiuose žurnaluose. Disertacijos tema perskaityta 11 pranešimų tarptautinėse konferencijose.Taip / Ye
Analysis of the impact of indoor climate conditions on office building energy modeling results
No full textTyrimas atliekamas naudojant dinaminio energinio modeliavimo programą IDA ICE. Tyrimo objekto, administracinės paskirties pastato, modelis sukurtas remiantis realiais duomenimis. Pastato energijos sąnaudos normalizuojamos, modelis kalibruojamas. Atlikti oro matavimai parodė, kad pastate susiduriama su sausu patalpų oru – tai didžiausia nagrinėjamo pastato mikroklimato problema. Pirminė simuliacija parodė, kad modelio rezultatai koreliuoja su atliktais matavimais. Žemos santykinės drėgmės problemai spręsti modelyje vėdinimo įrenginių oro tiekimo būdas pakeičiamas iš pastovaus oro srauto į kintamojo oro srautą su drėgmės reguliavimu. Pakeitus įvesties duomenis metinės energijos poreikis sumažėjo 6 MWh, o nepatenkintų žmonių kiekis (PPD) sumažėjo 3 %.The study is conducted using the dynamic energy modeling program IDA ICE. The model of the office building under investigation is created based on real data. The building’s energy consumption is normalized, and the model is calibrated. Air measurements have shown that the building is experiencing dry indoor air – this is the biggest microclimate issue of the building under investigation. The primary simulation has shown that the model results correlate with the conducted measurements. To address the low relative humidity issue, the ventilation system’s air supply mode is changed from constant air volume to variable air volume with humidity control. By changing the input data, the annual energy demand decreased by 6 MWh, and the percentage of dissatisfied people (PPD) also decreased by 3%.Taip / Ye
Remains of Gediminas Castle hill (Vilnius, Lithuania): 3D numerical model behaviour
No full textThis manuscript represents a historical influence of Gediminas Hill constructions and buildings for nowadays condition. According to latest investigations realized in 2019–2020 and obtained results, it was prepared three-dimensional numerical model. In this model it is included Gediminas Hill geological profiles with geotechnical parameters and Gediminas Castle remains (including pedestrian path, tunnels, funicular, etc.). Due to a very large computational resources necessity simulations realized in a private Vilnius Gediminas Technical University cloud. Created numerical model allows to simulate nowadays problems, mainly – slope stability. Gediminas Hill slope stability is lowest at the slope surfaces, where is the thickest technogenic soil layers. According to the shape and size of possible landslides formations, landslides assigned to shallow local landslides. Updated in-situ investigation results are used in the numerical model and it allows to simulate various environmental conditions which are affecting slopes stability and, in some case, can make influence for Gediminas Castel remains
Influence of geopolitical risk on stock volatility in the Middle East and North Africa states
No full textThe paper aims to explore the impact of geopolitical risk (GPR) on volatility dynamics in the Middle East and North Africa (MENA) states following the conflict between Ukraine and Russia (started in February 2022) and Israel and Hamas (started in October 2023). Fourteen states were analyzed between 01 January 2022 and 31 December 2023 using exponential general autoregressive conditional heteroskedastic (EGARCH) and vector autoregression (VAR). We find that GPR influenced the MENA markets slightly, and only Iraq reacted significantly to the Ukraine conflict. We also observed a clustering tendency of stock markets in the analyzed area and a slight influence in a few MENA states during the Israel–Hamas conflict. The MENA countries’ regulators and politicians, tasked with overseeing macro and micro rules based on a holistic approach that leaves no one behind, will find valuable information in this study. Because it demonstrates how quickly the stock markets respond to ongoing conflicts, this study also provides important insights to investors, managers, policymakers, and society at large.Taip / Yes
Spatial and Wavelet Attention-Enhanced Super-Resolution for Small Object Detection in Satellite Imagery
No full textEnhancing the detection of small objects in satellite imagery is of paramount importance for applications such as military surveillance and security monitoring. The challenge lies in addressing issues such as low resolution and image noise, which often lead to edge blurring and complicate object detection. This paper investigates super-resolution enhanced small object detection, particularly for ships in satellite images, employing a transformer-based architecture designed to emphasize and improve edge sharpness. The proposed model eliminates the window attention mechanism, substituting it with spatial and frequency self-attention to reinforce superior super-resolution detail learning, thereby enhancing the model's ability to capture finer details through spatial and frequency enhancements. Furthermore, the model optimizes performance by replacing depthwise-separable convolution, reducing computational complexity without compromising efficiency. Evaluated on the FGSCR dataset, with a specific focus on ship images, the proposed model achieves a notable 0.51 PSNR improvement and a 7% reduction in GFLOPs compared to the baseline SwinIR model. Finally, the proposed model was evaluated on YOLO object detection for practical application.Taip / Ye
Sustainable electromobility development in Lithuania comparing with EU countries in context of the European green deal
No full textThe global climate is currently warming due to human activity. The period 2011–2020 was recorded as the
warmest decade. CO2 produced by human activity is the biggest contributor to global warming. Since every ton of CO2 emitted contributes to global warming, all emissions reductions can help to slow it down. Currently, the cars used by the population still do not ensure a sufficient reduction of CO2 emissions. The purpose of paper is to investigate the potential of electromobility development as a means to mitigate CO2 emissions in EU countries. The research methodology: statistical and comparable analysis of environmental and economic factors influencing the electromobility development in EU countries during last decade were performed. The conclusions of paper provide results of electromobility development, the main obstacles and needed government policies and incentives.Taip / Yes
Education paradigm change and impact on sustainable economic development: A case study of Latvia
No full textThis research paper analyses the importance of a sustainable education-economy nexus in Latvia by analysing theoretical sources and expert opinions. The study reveals a paradigm shift in education towards an integrated, problem-oriented approach that promotes an eco-efficient economy. The focus is on synergies between education and industry, with particular emphasis on the role of knowledge-intensive business services in sustainable development. The article provides a new perspective of human capital on the interaction between education and the economy, pointing to the need for adaptive lifelong learning to promote sustainable economic development in Latvia. The results show that the Triple Helix integrated approach promotes knowledge sharing and positively recommends an innovation ecosystem, which is essential for sustainable economic development. However, the validity of the findings is limited by the country focus and data limitations. The study highlights the need for further research and improvements in policy making.Taip / Yes