Search results for: Aleksandra Boldyreva
71 Scanning Transmission Electron Microscopic Analysis of Gamma Ray Exposed Perovskite Solar Cells
Authors: Aleksandra Boldyreva, Alexander Golubnichiy, Artem Abakumov
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Various perovskite materials have surprisingly high resistance towards high-energy electrons, protons, and hard ionization, such as X-rays and gamma-rays. Superior radiation hardness makes a family of perovskite semiconductors an attractive candidate for single- and multijunction solar cells for the space environment and as X-ray and gamma-ray detectors. One of the methods to study the radiation hardness of different materials is by exposing them to gamma photons with high energies (above 500 keV) Herein, we have explored the recombination dynamics and defect concentration of a mixed cation mixed halide perovskite Cs0.17FA0.83PbI1.8Br1.2 with 1.74 eV bandgap after exposure to a gamma-ray source (2.5 Gy/min). We performed an advanced STEM EDX analysis to reveal different types of defects formed during gamma exposure. It was found that 10 kGy dose results in significant improvement of perovskite crystallinity and homogeneous distribution of I ions. While the absorber layer withstood gamma exposure, the hole transport layer (PTAA) as well as indium tin oxide (ITO) were significantly damaged, which increased the interface recombination rate and reduction of fill factor in solar cells. Thus, STEM analysis is a powerful technique that can reveal defects formed by gamma exposure in perovskite solar cells. Methods: Data will be collected from perovskite solar cells (PSCs) and thin films exposed to gamma ionisator. For thin films 50 μL of the Cs0.17FA0.83PbI1.8Br1.2 solution in DMF was deposited (dynamically) at 3000 rpm followed by quenching with 100 μL of ethyl acetate (dropped 10 sec after perovskite precursor) applied at the same spin-coating frequency. The deposited Cs0.17FA0.83PbI1.8Br1.2 films were annealed for 10 min at 100 °C, which led to the development of a dark brown color. For the solar cells, 10% suspension of SnO2 nanoparticles (Alfa Aesar) was deposited at 4000 rpm, followed by annealing on air at 170 ˚C for 20 min. Next, samples were introduced into a nitrogen glovebox for the deposition of all remaining layers. Perovskite film was applied in the same way as in thin films described earlier. Solution of poly-triaryl amine PTAA (Sigma Aldrich) (4 mg in chlorobenzene) was applied at 1000 rpm atop of perovskite layer. Next, 30 nm of VOx was deposited atop the PTAA layer on the whole sample surface using the physical vapor deposition (PVD) technique. Silver electrodes (100 nm) were evaporated in a high vacuum (10-6 mbar) through a shadow mask, defining the active area of each device as ~0.16 cm2. The prepared samples (thin films and solar cells) were packed in Al lamination foil inside the argon glove box. The set of samples consisted of 6 thin films and 6 solar cells, which were exposed to 6, 10, and 21 kGy (2 samples per dose) with 137Cs gamma-ray source (E = 662 keV) with a dose rate of 2.5 Gy/min. The exposed samples will be studied on a focused ion beam (FIB) on a dual-beam scanning electron microscope from ThermoFisher, the Helios G4 Plasma FIB Uxe, operating with a xenon plasma.Keywords: perovskite solar cells, transmission electron microscopy, radiation hardness, gamma irradiation
Procedia PDF Downloads 070 Phrasemes With The Component 'Water' In Polish And Russian - Comparative Aspects
Authors: Aleksandra Majewska
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The subject of this article is phrasemes with the component 'water' in Polish and Russian. The purpose of the study is to analyse the collocations from the point of view of lexis and semantics. The material for analysis was extracted from phraseological dictionaries of Polish and Russian. From the point of view of lexis, an analysis was made of the inflectional component 'water' in phrasal expressions in both languages. Then, the phrasemes were divided into their corresponding semantic groups. That division became the subject of another comparative analysis in a further step. Finally, the functioning of some phrasemes compounds in the contexts of modern Polish and Russian was shown.Keywords: lingustic, language, phraseme, polish and Russian
Procedia PDF Downloads 2569 Recovery of Acetonitrile from Aqueous Solutions by Extractive Distillation: The Effect of Entrainer
Authors: Aleksandra Y. Sazonova, Valentina M. Raeva
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The aim of this work was to apply extractive distillation for acetonitrile removal from water solutions, to validate thermodynamic criterion based on excess Gibbs energy to entrainer selection process for acetonitrile – water mixture separation and show its potential efficiency at isothermal conditions as well as at isobaric (conditions of real distillation process), to simulate and analyze an extractive distillation process with chosen entrainers: optimize amount of trays and feeds, entrainer/original mixture and reflux ratios. Equimolar composition of the feed stream was chosen for the process, comparison of the energy consumptions was carried out. Glycerol was suggested as the most energetically and ecologically suitable entrainer.Keywords: acetonitrile, entrainer, extractive distillation, water
Procedia PDF Downloads 25668 Influence of Lecithin from Different Sources on Crystallization Properties of Non-Trans Fat
Authors: Ivana Lončarević, Biljana Pajin, Radovan Omorjan, Aleksandra Torbica, Danica Zarić, Jovana Maksimović
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Soybean seeds are the main source of lecithin in confectionery industry in Serbia and elsewhere. The extensive production of sunflower and rapeseed oil opens the possibility of using lecithin from these sources, as an alternative. Also, the development of functional foods dictates the use of edible fats with no undesirable trans fatty acids, obtained by fractionation and transesterification instead of common hydrogenation process. Crystallization properties of nontrans vegetable fat with the addition of soybean, sunflower and rapeseed lecithin were investigated in this paper. NMR technique was used for measuring the solid fat content (SFC) of fats at different temperatures, as well as for crystallization rate under static conditions. Also, the possibility of applying Gompertz function to define kinetics of crystallization was investigated.Keywords: non-trans fat, lecithin, fatty acids, SFC
Procedia PDF Downloads 45167 Ab Initio Multiscale Catalytic Synthesis/Cracking Reaction Modelling of Ammonia as Liquid Hydrogen Carrier
Authors: Blaž Likozar, Andraž Pavlišič, Matic Pavlin, Taja Žibert, Aleksandra Zamljen, Sašo Gyergyek, Matej Huš
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Ammonia is gaining recognition as a carbon-free fuel for energy-intensive applications, particularly transportation, industry, and power generation. Due to its physical properties, high energy density of 3 kWh kg-1, and high gravimetric hydrogen capacity of 17.6 wt%, ammonia is an efficient energy vector for green hydrogen, capable of mitigating hydrogen’s storage, distribution, and infrastructure deployment limitations. Chemicalstorage in the form of ammonia provides an efficient and affordable solution for energy storage, which is currently a critical step in overcoming the intermittency of abundant renewable energy sources with minimal or no environmental impact. Experiments were carried out to validate the modelling in a packed bed reactor, which proved to be agreeing.Keywords: hydrogen, ammonia, catalysis, modelling, kinetics
Procedia PDF Downloads 5666 Direct Assessment of Cellular Immune Responses to Ovalbumin with a Secreted Luciferase Transgenic Reporter Mouse Strain IFNγ-Lucia
Authors: Martyna Chotomska, Aleksandra Studzinska, Marta Lisowska, Justyna Szubert, Aleksandra Tabis, Jacek Bania, Arkadiusz Miazek
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Objectives: Assessing antigen-specific T cell responses is of utmost importance for the pre-clinical testing of prototype vaccines against intracellular pathogens and tumor antigens. Mainly two types of in vitro assays are used for this purpose 1) enzyme-linked immunospot (ELISpot) and 2) intracellular cytokine staining (ICS). Both are time-consuming, relatively expensive, and require manual dexterity. Here, we assess if a straightforward detection of luciferase activity in blood samples of transgenic reporter mice expressing a secreted Lucia luciferase under the transcriptional control of IFN-γ promoter parallels the sensitivity of IFNγ ELISpot assay. Methods: IFN-γ-LUCIA mouse strain carrying multiple copies of Lucia luciferase transgene under the transcriptional control of IFNγ minimal promoter were generated by pronuclear injection of linear DNA. The specificity of transgene expression and mobilization was assessed in vitro using transgenic splenocytes exposed to various mitogens. The IFN-γ-LUCIA mice were immunized with 50mg of ovalbumin (OVA) emulsified in incomplete Freund’s adjuvant three times every two weeks by subcutaneous injections. Blood samples were collected before and five days after each immunization. Luciferase activity was assessed in blood serum. Peripheral blood mononuclear cells were separated and assessed for frequencies of OVA-specific IFNγ-secreting T cells. Results: We show that in vitro cultured splenocytes of IFN-γ-LUCIA mice respond by 2 and 3 fold increase in secreted luciferase activity to T cell mitogens concanavalin A and phorbol myristate acetate, respectively but fail to respond to B cell-stimulating E.coli lipopolysaccharide. Immunization of IFN-γ-LUCIA mice with OVA leads to over 4 fold increase in luciferase activity in blood serum five days post-immunization with a barely detectable increase in OVA-specific, IFNγ-secreting T cells by ELISpot. Second and third immunizations, further increase the luciferase activity and coincidently also increase the frequencies of OVA-specific T cells by ELISpot. Conclusions: We conclude that minimally invasive monitoring of luciferase secretions in blood serum of IFN-γ-LUCIA mice constitutes a sensitive method for evaluating primary and memory Th1 responses to protein antigens. As such, this method may complement existing methods for rapid immunogenicity assessment of prototype vaccines.Keywords: ELISpot, immunogenicity, interferon-gamma, reporter mice, vaccines
Procedia PDF Downloads 16065 Online Authenticity Verification of a Biometric Signature Using Dynamic Time Warping Method and Neural Networks
Authors: Gałka Aleksandra, Jelińska Justyna, Masiak Albert, Walentukiewicz Krzysztof
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An offline signature is well-known however not the safest way to verify identity. Nowadays, to ensure proper authentication, i.e. in banking systems, multimodal verification is more widely used. In this paper the online signature analysis based on dynamic time warping (DTW) coupled with machine learning approaches has been presented. In our research signatures made with biometric pens were gathered. Signature features as well as their forgeries have been described. For verification of authenticity various methods were used including convolutional neural networks using DTW matrix and multilayer perceptron using sums of DTW matrix paths. System efficiency has been evaluated on signatures and signature forgeries collected on the same day. Results are presented and discussed in this paper.Keywords: dynamic time warping, handwritten signature verification, feature-based recognition, online signature
Procedia PDF Downloads 16164 Creativity and Stereotype Threat: Analysis of the Impact of Creativity on Eliminating the Stereotype Threat in the Educational Setting
Authors: Aleksandra Gajda
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Among students between 12 and 13, the probability of activating the stereotype threat increases noticeably. Girls consider themselves weaker in science, while boys consider themselves weaker in the field of language skills. This phenomenon is disturbing because it may result in wrong choices of the further path of education, not consistent with the actual competences of the students. Meanwhile, negative effects of the stereotype threat, observable in the loss of focus on the task and transferring it to dealing with fear of failure, can be reduced by various factors. The study examined the impact of creativity on eliminating the stereotype threat. The experiment in the form of a 2 (gender: male vs. female) x 3 (traditional gender roles: neutral version vs. nontraditional gender roles) x 2 (creativity: low vs. high) factorial design was conducted. The results showed that a high level of creative abilities may reduce the negative effects of stereotype threat in educational setting.Keywords: creativity, education, language skills, mathematical skills, stereotype threat
Procedia PDF Downloads 10863 Simulation of Wave Propagation in Multiphase Medium
Authors: Edip Kemal, Sheshov Vlatko, Bojadjieva Julijana, Bogdanovic ALeksandra, Gjorgjeska Irena
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The wave propagation phenomenon in porous domains is of great importance in the field of geotechnical earthquake engineering. In these kinds of problems, the elastic waves propagate from the interior to the exterior domain and require special treatment at the computational level since apart from displacement in the solid-state there is a p-wave that takes place in the pore water phase. In this paper, a study on the implementation of multiphase finite elements is presented. The proposed algorithm is implemented in the ANSYS finite element software and tested on one-dimensional wave propagation considering both pore pressure wave propagation and displacement fields. In the simulation of porous media such as soils, the behavior is governed largely by the interaction of the solid skeleton with water and/or air in the pores. Therefore, coupled problems of fluid flow and deformation of the solid skeleton are considered in a detailed way.Keywords: wave propagation, multiphase model, numerical methods, finite element method
Procedia PDF Downloads 15862 ExactData Smart Tool For Marketing Analysis
Authors: Aleksandra Jonas, Aleksandra Gronowska, Maciej Ścigacz, Szymon Jadczak
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Exact Data is a smart tool which helps with meaningful marketing content creation. It helps marketers achieve this by analyzing the text of an advertisement before and after its publication on social media sites like Facebook or Instagram. In our research we focus on four areas of natural language processing (NLP): grammar correction, sentiment analysis, irony detection and advertisement interpretation. Our research has identified a considerable lack of NLP tools for the Polish language, which specifically aid online marketers. In light of this, our research team has set out to create a robust and versatile NLP tool for the Polish language. The primary objective of our research is to develop a tool that can perform a range of language processing tasks in this language, such as sentiment analysis, text classification, text correction and text interpretation. Our team has been working diligently to create a tool that is accurate, reliable, and adaptable to the specific linguistic features of Polish, and that can provide valuable insights for a wide range of marketers needs. In addition to the Polish language version, we are also developing an English version of the tool, which will enable us to expand the reach and impact of our research to a wider audience. Another area of focus in our research involves tackling the challenge of the limited availability of linguistically diverse corpora for non-English languages, which presents a significant barrier in the development of NLP applications. One approach we have been pursuing is the translation of existing English corpora, which would enable us to use the wealth of linguistic resources available in English for other languages. Furthermore, we are looking into other methods, such as gathering language samples from social media platforms. By analyzing the language used in social media posts, we can collect a wide range of data that reflects the unique linguistic characteristics of specific regions and communities, which can then be used to enhance the accuracy and performance of NLP algorithms for non-English languages. In doing so, we hope to broaden the scope and capabilities of NLP applications. Our research focuses on several key NLP techniques including sentiment analysis, text classification, text interpretation and text correction. To ensure that we can achieve the best possible performance for these techniques, we are evaluating and comparing different approaches and strategies for implementing them. We are exploring a range of different methods, including transformers and convolutional neural networks (CNNs), to determine which ones are most effective for different types of NLP tasks. By analyzing the strengths and weaknesses of each approach, we can identify the most effective techniques for specific use cases, and further enhance the performance of our tool. Our research aims to create a tool, which can provide a comprehensive analysis of advertising effectiveness, allowing marketers to identify areas for improvement and optimize their advertising strategies. The results of this study suggest that a smart tool for advertisement analysis can provide valuable insights for businesses seeking to create effective advertising campaigns.Keywords: NLP, AI, IT, language, marketing, analysis
Procedia PDF Downloads 7561 Biological Evaluation and Molecular Modeling Study of Thiosemicarbazide Derivatives as Bacterial Type IIA Topoisomerases Inhibitors
Authors: Paweł Stączek, Tomasz Plech, Aleksandra Strzelczyk, Katarzyna Dzitko, Monika Wujec, Edyta Kuśmierz, Piotr Paneth, Agata Paneth
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In this contribution, we will describe the inhibitory potency of nine thiosemicarbazide derivatives against bacterial type IIA topoisomerases, their antibacterial profile, and molecular modeling evaluation. We have found that one of the tested compounds, 4-benzoyl-1-(2-methyl-furan-3-ylcarbonyl) thiosemicarbazide, remarkably inhibits the activity of S. aureus DNA gyrase with the IC50 below 5 μM. Besides, this compound displays antibacterial activity on Staphylococcus spp. and E. faecalis at non-cytotoxic concentrations in mammalian cells, with minimal inhibitory concentrations (MICs) values at 25 μg/mL. Based on the enzymatic and molecular modeling studies we propose two factors, i.e. geometry of molecule and hydrophobic/hydrophilic balance as important molecular properties for developing thiosemicarbazide derivatives as potent Staphylococcus aureus DNA gyrase inhibitors.Keywords: bioactivity, drug design, topoisomerase, molecular modeling
Procedia PDF Downloads 55560 A Method of Effective Planning and Control of Industrial Facility Energy Consumption
Authors: Aleksandra Aleksandrovna Filimonova, Lev Sergeevich Kazarinov, Tatyana Aleksandrovna Barbasova
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A method of effective planning and control of industrial facility energy consumption is offered. The method allows to optimally arrange the management and full control of complex production facilities in accordance with the criteria of minimal technical and economic losses at the forecasting control. The method is based on the optimal construction of the power efficiency characteristics with the prescribed accuracy. The problem of optimal designing of the forecasting model is solved on the basis of three criteria: maximizing the weighted sum of the points of forecasting with the prescribed accuracy; the solving of the problem by the standard principles at the incomplete statistic data on the basis of minimization of the regularized function; minimizing the technical and economic losses due to the forecasting errors.Keywords: energy consumption, energy efficiency, energy management system, forecasting model, power efficiency characteristics
Procedia PDF Downloads 38059 Chemometric Estimation of Phytochemicals Affecting the Antioxidant Potential of Lettuce
Authors: Milica Karadzic, Lidija Jevric, Sanja Podunavac-Kuzmanovic, Strahinja Kovacevic, Aleksandra Tepic-Horecki, Zdravko Sumic
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In this paper, the influence of six different phytochemical content (phenols, carotenoids, chlorophyll a, chlorophyll b, chlorophyll a + b and vitamin C) on antioxidant potential of Murai and Levistro lettuce varieties was evaluated. Variable selection was made by generalized pair correlation method (GPCM) as a novel ranking method. This method is used for the discrimination between two variables that almost equal correlate to a dependent variable. Fisher’s conditional exact and McNemar’s test were carried out. Established multiple linear (MLR) models were statistically evaluated. As the best phytochemicals for the antioxidant potential prediction, chlorophyll a, chlorophyll a + b and total carotenoids content stand out. This was confirmed through both GPCM and MLR, predictive ability of obtained MLR can be used for antioxidant potential estimation for similar lettuce samples. This article is based upon work from the project of the Provincial Secretariat for Science and Technological Development of Vojvodina (No. 114-451-347/2015-02).Keywords: antioxidant activity, generalized pair correlation method, lettuce, regression analysis
Procedia PDF Downloads 38158 The Impact of Corn Grain Consolidation on the Emission of Volatile Organic Compounds
Authors: Marek Gancarz, Katarzyna Grądecka-Jakubowska, Urszula Malaga-Toboła, Rafał Kornas, Aleksandra Żytek, Robert Rusinek
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The aim of the research was to determine the emission of volatile organic compounds (VOCs) from corn grain depending on the degree of consolidation of the bulk material, imitating the processes occurring in silos during material storage. An electronic nose and a gas chromatograph were used for VOC analysis. Corn grain was densified under pressure of 40 and 80 kPa. Control samples of corn grain were not compacted and had bulk density. The analyzes were carried out at 14% and 17% humidity (w.b. – wet basis). The measurement system enabled quantitative and qualitative analyzes of volatile compounds and their emission intensity during the 10-day storage period. The study determined the profile of volatile compounds as a function of storage time and grain density level. The test results showed that the highest emission of volatile compounds was recorded in the first four days of storage of corn grain. VOC emissions, as well as grain moisture and volume, can be helpful in determining the quality of material stored in silos and its subsequent suitability for consumption.Keywords: maize, consolidation, storage, VOCs, GC-MS, chemometrics
Procedia PDF Downloads 7057 Controversies Connected with the Admission of Illegally Gained Evidences in Polish Civil Proceedings
Authors: Aleksandra Czubak
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The need to present evidence in civil proceedings is essential for getting the right result. It is for this reason that it is particularly important for the parties to present the most relevant and convincing evidence to the Court. Therefore, parties often try to gain evidence, even when the acquisition of such evidence is in breach of the law. Firstly, there will be discussed how evidence is applied in the Polish civil process and the Polish regulations of the evidence proceedings; with specific reference to evidence of major importance in the developing world. Further, it will be discussed the controversies connected with the admission of illegally gained evidence in civil proceedings. The credibility of the various measures is circumstantial and can only be determined by factors related to the recognized problem. For that reason, it is not the amount of evidence, but the value and relevance of this evidence that should be considered in determining the right result. This paper will also consider whether the end justifies the means? How far should parties go in order to achieve a favorable sentence or to create stronger evidence? Methods of persuasion of the court, as well as the acquisition of evidence, are not always fair and moral. It is on this area of controversy that this essay will focus. This paper concludes by considering the value of evidence and the possibility of using it to achieve a just sentence. Examples are based on Polish law; nevertheless, they encompass ideas common to most civil jurisdictions.Keywords: civil proceedings, Europe (Poland), evidence, law
Procedia PDF Downloads 24456 Energy Consumption Forecast Procedure for an Industrial Facility
Authors: Tatyana Aleksandrovna Barbasova, Lev Sergeevich Kazarinov, Olga Valerevna Kolesnikova, Aleksandra Aleksandrovna Filimonova
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We regard forecasting of energy consumption by private production areas of a large industrial facility as well as by the facility itself. As for production areas the forecast is made based on empirical dependencies of the specific energy consumption and the production output. As for the facility itself implementation of the task to minimize the energy consumption forecasting error is based on adjustment of the facility’s actual energy consumption values evaluated with the metering device and the total design energy consumption of separate production areas of the facility. The suggested procedure of optimal energy consumption was tested based on the actual data of core product output and energy consumption by a group of workshops and power plants of the large iron and steel facility. Test results show that implementation of this procedure gives the mean accuracy of energy consumption forecasting for winter 2014 of 0.11% for the group of workshops and 0.137% for the power plants.Keywords: energy consumption, energy consumption forecasting error, energy efficiency, forecasting accuracy, forecasting
Procedia PDF Downloads 43455 Non-Standard Monetary Policy Measures and Their Consequences
Authors: Aleksandra Nocoń (Szunke)
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The study is a review of the literature concerning the consequences of non-standard monetary policy, which are used by central banks during unconventional periods, threatening instability of the banking sector. In particular, the attention was paid to the effects of non-standard monetary policy tools for financial markets. However, the empirical evidence about their effects and real consequences for the financial markets are still not final. The main aim of the study is to survey the consequences of standard and non-standard monetary policy instruments, implemented during the global financial crisis in the United States, United Kingdom and Euroland, with particular attention to the results for the stabilization of global financial markets. The study analyses the consequences for short and long-term market interest rates, interbank interest rates and LIBOR-OIS spread. The study consists mainly of the empirical review, indicating the impact of the implementation of these tools for the financial markets. The following research methods were used in the study: literature studies, including domestic and foreign literature, cause and effect analysis and statistical analysis.Keywords: asset purchase facility, consequences of monetary policy instruments, non-standard monetary policy, quantitative easing
Procedia PDF Downloads 32254 Protection of Human Rights in Europe: The Parliamentary Dimension
Authors: Aleksandra Chiniaeva
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The following paper describes the activity of national and international parliamentary assemblies of the European region in protection and promotion of human rights. It may be said that parliamentarians have a “double mandate” — as members of the international assembly and of their respective national parliaments. In other words, parliamentarization at both international and national level provides a situation for parliamentarians, where they link people, national governments and international organizations. The paper is aimed towards demonstrating that the activity of the main international parliamentary assemblies of the European region have a real positive impact on the human rights situation in the European region. In addition, the paper describes the assemblies that include protection of human rights in their Agenda as one of the main subjects: the EP, the PACE, the OSCE PA and the IPA CIS. Co-operation activities such as joint election observation; participation in inter-parliamentary associations, such as the IPU; conclusion agreements allow assemblies to provide observation of human right situation in the states that are not members of the particular organization and as consequence make their impact broader.Keywords: human rights, international parliamentary assembly, IPU, EP, PACE, OSCE, international election observation
Procedia PDF Downloads 35553 Antioxidant Characteristics of Serbian Conifers
Authors: Dubravka Štajner, Boris M. Popović, Saša Orlović, Ružica Ždero, Milan Popović, Aleksandra Popović
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Many plants possess antioxidant ingredients that provides efficacy by additive or synergistic activities. Present article highlights an antioxidant capacity of Serbian conifer plants. Antioxidant activities of the crude extracts were assessed using different assays. In this study, quantities of phenolic compounds (total phenols, flavonoids, tannins and proanthocyanidins), contents of photosynthetic pigments (chlorophyll a and b and carotenoids), soluble proteins and proline were examined. MDA quantities and ability of extracts to remove reactive nitrogen and oxygen species (RNOS) were also investigated. Furthermore, antioxidant activities of extracts against DPPH∙, ferric reducing antioxidant power, permanganate reducing antioxidant capacity were also determined. According to almost all used assays, antioxidant and scavenging capacities of silver fir (Abies alba Mill.), and Douglas fir (Pseudotsuga menziesii) were superior compared to spruce. Presented results implicated that leaves of Douglas fir and silver fir possessed outstanding antioxidant characteristics that could diminish damage caused by oxygen radicals which are responsible for many of the bodily changes and susceptibility to different diseases.Keywords: conifers, antioxidant activity, reducing power, lipid peroxidation
Procedia PDF Downloads 33652 Traumatic Experiences as the Predictor of Maladaptive Outcomes among Children in Foster Care
Authors: Aleksandra Bogdanovic, Milicat Tošić Radev, Tatjana Stefanovic Stanojevic
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The aim behind this study was to first analyze the nature and the extent of childhood trauma and existing maladaptive outcomes (internalized and externalized problems and dissociation) among adolescents in the foster system and then analyze the possibility of using traumatic experiences to predict the aforementioned outcomes of childhood trauma. The sample consists of 121 respondents, children, and youths in the care of child protective services, without adequate parental care, residing in temporary foster care families on the territory of Serbia, aged between 11 and 18. The respondents filled out the Childhood Trauma Questionnaire – CTQ, Relationship Questionaire – Clinical version RQ-CV, the Dissociative experience scale for adolescents, A-DES and the Child behavior checklist – youth self-report. The results of the analyses have indicated that physical and emotional neglect are the most frequent forms of maltreatment in early childhood, with a relatively high prevalence of the other individual forms of trauma. Early childhood trauma statistically significantly predicted all the analyzed maladaptive outcomes, explaining approximately 20% of the variance of internalized and externalized problems and dissociation. Recommendations are given for future studies.Keywords: trauma, maladaptive outcomes, disorganization, dissociation
Procedia PDF Downloads 8951 Implementing a Neural Network on a Low-Power and Mobile Cluster to Aide Drivers with Predictive AI for Traffic Behavior
Authors: Christopher Lama, Alix Rieser, Aleksandra Molchanova, Charles Thangaraj
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New technologies like Tesla’s Dojo have made high-performance embedded computing more available. Although automobile computing has developed and benefited enormously from these more recent technologies, the costs are still high, prohibitively high in some cases for broader adaptation, particularly for the after-market and enthusiast markets. This project aims to implement a Raspberry Pi-based low-power (under one hundred Watts) highly mobile computing cluster for a neural network. The computing cluster built from off-the-shelf components is more affordable and, therefore, makes wider adoption possible. The paper describes the design of the neural network, Raspberry Pi-based cluster, and applications the cluster will run. The neural network will use input data from sensors and cameras to project a live view of the road state as the user drives. The neural network will be trained to predict traffic behavior and generate warnings when potentially dangerous situations are predicted. The significant outcomes of this study will be two folds, firstly, to implement and test the low-cost cluster, and secondly, to ascertain the effectiveness of the predictive AI implemented on the cluster.Keywords: CS pedagogy, student research, cluster computing, machine learning
Procedia PDF Downloads 9050 Precocious Puberty Due to an Autonomous Ovarian Cyst in a 3-Year-Old Girl: Case Report
Authors: Aleksandra Chałupnik, Zuzanna Chilimoniuk, Joanna Borowik, Aleksandra Borkowska, Anna Torres
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Background: Precocious puberty is the occurrence of secondary sexual characteristics in girls before the age of 8. The diverse etiology of premature puberty is crucial to determine whether it is true precocious puberty, depending on the activation of the hypothalamic-pituitary-gonadal axis, or pseudo-precocious, which is independent of the activation of this axis. Whatever the cause, premature action of the sex hormones leads to the common symptoms of various forms of puberty. These include the development of sexual characteristics, acne, acceleration of growth rate and acceleration of skeletal maturation. Due to the possible genetic basis of the disorders, an interdisciplinary search for the cause is needed. Case report: The case report concerns a patient of a pediatric gynecology clinic who, at the age of two years, developed advanced thelarhe (M3) and started recurrent vaginal bleeding. In August 2019, gonadotropin suppression initially and after LHRH stimulation and high estradiol levels were reported at the Endocrinology Department. Imaging examinations showed a cyst in the right ovary projection. The bone age was six years. The entire clinical picture indicated pseudo- (peripheral) precocious in the course of ovarian autonomic cyst. In the follow-up ultrasound performed in September, the image of the cyst was stationary and normalization of estradiol levels and clinical symptoms was noted. In December 2019, cyst regression and normal gonadotropin and estradiol concentrations were found. In June 2020, white mucus tinged with blood on the underwear, without any other disturbing symptoms, was observed for several days. Two consecutive USG examinations carried out in the same month confirmed the change in the right ovary, the diameter of which was 25 mm with a very high level of estradiol. Germinal tumor markers were normal. On the Tanner scale, the patient scored M2P1. The labia and hymen had puberty features. The correct vaginal entrance was visible. Another active vaginal bleeding occurred in the first week of July 2020. The considered laparoscopic treatment was abandoned due to the lack of oncological indications. Treatment with Tamoxifen was recommended in July 2020. In the initiating period of treatment, no maturation progression, and even reduction of symptoms, no acceleration of growth and a marked reduction in the size of the cysts were noted. There was no bleeding. After the size of the cyst and hormonal activity increased again, the treatment was changed to Anastrozole, the effect of which led to a reduction in the size of the cyst. Conclusions: The entire clinical picture indicates alleged (peripheral) puberty. Premature puberty in girls, which is manifested as enlarged mammary glands with high levels of estrogens secreted by autonomic ovarian cysts and prepubertal levels of gonadotropins, may indicate McCune-Albright syndrome. Vaginal bleeding may also occur in this syndrome. Cancellation of surgical treatment of the cyst made it impossible to perform a molecular test that would allow to confirm the diagnosis. Taking into account the fact that cysts are often one of the first symptoms of McCune-Albrigt syndrome, it is important to remember about multidisciplinary care for the patient and careful search for skin and bone changes or other hormonal disorders.Keywords: McCune Albrigth's syndrome, ovarian cyst, pediatric gynaecology, precocious puberty
Procedia PDF Downloads 18349 Pros and Cons of Distance Learning in Europe and Perspective for the Future
Authors: Aleksandra Ristic
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The Coronavirus Disease – 2019 hit Europe in February 2020, and infections took place in four waves. It left consequences and demanded changes for the future. More than half of European countries responded quickly by declaring a state of emergency and introducing various containment measures that have had a major impact on individuals’ lives in recent years. Closing public lives was largely achieved by limited access and/or closing public institutions and services, including the closure of educational institutions. Teaching in classrooms converted to distance learning. In the research, we used a quantitative study to analyze various factors of distance learning that influenced pupils in different segments: teachers’ availability, family support, entire online conference learning, successful distance learning, time for themselves, reliable sources, teachers’ feedback, successful distance learning, online participation classes, motivation and teachers’ communication and theoretical review of the importance of digital skills, e-learning Index, World comparison of e-learning in the past, digital education plans for the field of Europe. We have gathered recommendations and distance learning solutions to improve the learning process by strengthening teachers and creating more tiered strategies for setting and achieving learning goals by the children.Keywords: availability, digital skills, distance learning, resources
Procedia PDF Downloads 9148 Gymnastics Under Special Surveillance. The Impact Of Western Sanctions On Russian Sport
Authors: Aleksandra Majewska
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The article analyses the impact of Western sanctions on Russian rhythmic gymnastics since the outbreak of war in Ukraine. The chronological presentation of events shows how international political tensions and economic sanctions have affected the organisation of competitions, training and the careers of athletes. The article outlines the key moments and decisions that have changed the landscape of Russian sport, including the decision to change the citizenship made by some gymnasts in order to continue competing in international competitions. Russia strongly opposes participation in competitions without its flag and anthem while maintaining the view that Russian gymnasts are crucial to the prestige of rhythmic gymnastics in the world. In response to the sanctions, Russia created its own rules for rhythmic gymnastics, according to which they now compete domestically. Furthermore, this sport in Russia is strongly linked to politics, which further emphasises its importance in the national and international context. The information collected derives from numerous interviews with Russian athletes, coaches and other people, which are available only in the Russian language. The findings highlight the significant difficulties Russian athletes have faced due to their isolation in the international arena and the adaptive strategies adopted by Russia in the face of these challenges. The article makes an important contribution to understanding the consequences of global politics on the world of sport and the fate of individual athletes.Keywords: sport, gymnastics, war in Ukraine, sanctions
Procedia PDF Downloads 2847 Application of a Geomechanical Model to Justify the Exploitation of Bazhenov-Abalak Formation, Western Siberia
Authors: Yan Yusupov, Aleksandra Soldatova, Yaroslav Zaglyadin
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The object of this work is Bazhenov-Abalak unconventional formation (BAUF) of Western Siberia. On the base of the Geomechanical model (GMM), a methodology was developed for sweet spot intervals and zones for drilling horizontal wells with hydraulic fracturing. Based on mechanical rock typification, eight mechanical rock types (MRT) have been identified. Sweet spot intervals are represented by siliceous-carbonate (2), siliceous (5) and carbonate (8) MRT that have the greatest brittleness index (BRIT). A correlation has been established between the thickness of brittle intervals and the initial well production rates, which makes it possible to identify sweet spot zones for drilling horizontal wells with hydraulic fracturing. Brittle and ductile intervals are separated by a BRIT cut-off of 0.4 since wells located at points with BRIT < 0.4 have insignificant rates (less than 2 m³/day). Wells with an average BRIT in BAUF of more than 0.4 reach industrial production rates. The next application of GMM is associated with the instability of the overburdened clay formation above the top of the BAUF. According to the wellbore stability analysis, the recommended mud weight for this formation must be not less than 1.53–1.55 g/cc. The optimal direction for horizontal wells corresponds to the azimuth of Shmin equal to 70-80°.Keywords: unconventional reservoirs, geomechanics, sweet spot zones, borehole stability
Procedia PDF Downloads 5746 Study on the Presence of Protozoal Coinfections among Patients with Pneumocystis jirovecii Pneumonia in Bulgaria
Authors: Nina Tsvetkova, Rumen Harizanov, Aleksandra Ivanova, Iskra Rainova, Nina Yancheva-Petrova, Dimitar Strashimirov, Raina Enikova, Mihaela Videnova, Eleonora Kaneva, Iskren Kaftandjiev, Viktoria Levterova, Ivan Simeonovski, Nikolay Yanev, Georgi Hinkov
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The Pneumocystis jirovecii (P. jirovecii) and protozoan of the genera Acanthamoeba, Cryptosporidium, and Toxoplasma gondii are opportunistic pathogens that can cause life-threatening infections in immunocompromised patients. Aim of the study was to evaluate the coinfection rate with opportunistic protozoal agents among Bulgarian patients diagnosed with P. jirovecii pneumonia. Thirty-eight pulmonary samples were collected from 38 patients (28 HIV-infected) with P. jirovecii infection. P. jirovecii DNA was detected by real-time PCR targeting the large mitochondrial subunit ribosomal RNA gene. Acanthamoeba was determined by genus-specific conventional PCR assay. Real-time PCR for the detection of a Toxoplasma gondii and Cryptosporidium DNA fragment was used. Pneumocystis DNA was detected in all 38 specimens; 28 (73.7%) were from HIV-infected patients. Three (10,7%) of them were co-infected with T. gondii and 1 (3.6%) with Cryptosporidium. In the group of non-HIV-infected (n=10), Cryptosporidium DNA was detected in an infant (10%). Acanthamoeba DNA was not found in the tested samples. The current study showed a relatively low rate of coinfections of Cryptosporidium spp./T. gondii and P. jirovecii in the Bulgarian patients studied.Keywords: coinfection, opportunistic protozoal agents, Pneumocystis jirovecii, pulmonary infections
Procedia PDF Downloads 14645 An Approach for Vocal Register Recognition Based on Spectral Analysis of Singing
Authors: Aleksandra Zysk, Pawel Badura
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Recognizing and controlling vocal registers during singing is a difficult task for beginner vocalist. It requires among others identifying which part of natural resonators is being used when a sound propagates through the body. Thus, an application has been designed allowing for sound recording, automatic vocal register recognition (VRR), and a graphical user interface providing real-time visualization of the signal and recognition results. Six spectral features are determined for each time frame and passed to the support vector machine classifier yielding a binary decision on the head or chest register assignment of the segment. The classification training and testing data have been recorded by ten professional female singers (soprano, aged 19-29) performing sounds for both chest and head register. The classification accuracy exceeded 93% in each of various validation schemes. Apart from a hard two-class clustering, the support vector classifier returns also information on the distance between particular feature vector and the discrimination hyperplane in a feature space. Such an information reflects the level of certainty of the vocal register classification in a fuzzy way. Thus, the designed recognition and training application is able to assess and visualize the continuous trend in singing in a user-friendly graphical mode providing an easy way to control the vocal emission.Keywords: classification, singing, spectral analysis, vocal emission, vocal register
Procedia PDF Downloads 29444 The Influence of Silica on the Properties of Cementitious Composites
Authors: Eva Stefanovska, Estefania Cuenca, Aleksandra Momirov, Monika Fidanchevska, Liberato Ferrara, Emilija Fidanchevski
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Silica is used in construction materials as a part of natural raw materials or as an additive in powder form (micro and nano dimensions). SiO₂ particles in cement act as centers of nucleation, as a filler or as pozzolan material. In this regard, silica improves the microstructure of cementitious composites, increases the mechanical properties, and finally also results into improved durability of the final products. Improved properties of cementitious composites may lead to better structural efficiency, which, together with increased durability, results into increased sustainability signature of structures made with this kind of materials. The aim of the present work was to investigate the influence of silica on the properties of cement. Fly ash (as received and mechanically activated) and synthetized silica (sol-gel method using TEOS as precursor) was used in the investigation as source of silica. Four types of cement mixtures were investigated (reference cement paste, cement paste with addition of 15wt.% as-received fly ash, cement paste with 15 wt.% mechanically activated fly ash and cement paste with 14wt.% mechanically activated fly ash and 1 wt.% silica). The influence of silica on setting time and mechanical properties (2, 7 and 28 days) was followed. As a matter of fact it will be shown that cement paste with composition 85 wt. % cement, 14 wt.% mechanically activated fly ash and 1 wt. % SiO₂ obtained by the sol-gel method was the best performing one, with increased compressive and flexure strength by 9 and 10 % respectively, as compared to the reference mixture. Acknowledgements: 'COST Action CA15202, www.sarcos.eng.cam.ac.uk'Keywords: cement, fly ash, mechanical properties, silica, sol-gel
Procedia PDF Downloads 13443 Hyaluronic Acid Binding to Link Domain of Stabilin-2 Receptor
Authors: Aleksandra Twarda, Dobrosława Krzemień, Grzegorz Dubin, Tad A. Holak
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Stabilin-2 belongs to the group of scavenger receptors and plays a crucial role in clearance of more than 10 ligands from the bloodstream, including hyaluronic acid, products of degradation of extracellular matrix and metabolic products. The Link domain, a defining feature of stabilin-2, has a sequence similar to Link domains in other hyaluronic acid receptors, such as CD44 or TSG-6, and is responsible for most of ligands binding. Present knowledge of signal transduction by stabilin-2, as well as ligands’ recognition and binding mechanism, is limited. Until now, no experimental structures have been solved for any segments of stabilin-2. It has recently been demonstrated that the stabilin-2 knock-out or blocking of the receptor by an antibody effectively opposes cancer metastasis by elevating the level of circulating hyaluronic acid. Moreover, loss of expression of stabilin-2 in a peri-tumourous liver correlates with increased survival. Solving of the crystal structure of stabilin-2 and elucidation of the binding mechanism of hyaluronic acid could enable the precise characterization of the interactions in the binding site. These results may allow for designing specific small-molecule inhibitors of stabilin-2 that could be used in cancer therapy. To carry out screening for crystallization of stabilin-2, we cloned constructs of the Link domain of various lengths with or without surrounding domains. The folding properties of the constructs were checked by nuclear magnetic resonance (NMR). It is planned to show the binding of hyaluronic acid to the Link domain using several biochemical methods, i.a. NMR, isothermal titration calorimetry and fluorescence polarization assay.Keywords: stabilin-2, Link domain, X-ray crystallography, NMR, hyaluronic acid, cancer
Procedia PDF Downloads 39442 Transmission of Values among Polish Young Adults and Their Parents: Pseudo Dyad Analysis and Gender Differences
Authors: Karolina Pietras, Joanna Fryt, Aleksandra Gronostaj, Tomasz Smolen
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Young women and men differ from their parents in preferred values. Those differences enable their adaptability to a new socio-cultural context and help with fulfilling developmental tasks specific to young adulthood. At the same time core values, with special importance to family members, are transmitted within families. Intergenerational similarities in values may thus be both an effect of value transmission within a family and a consequence of sharing the same socio-cultural context. These processes are difficult to separate. In our study we assessed similarities and differences in values within four intergenerational family dyads (mothers-daughters, fathers-daughters, mothers-sons, fathers-sons). Sixty Polish young adults (30 women and 30 men aged 19-25) along with their parents (a total of 180 participants) completed the Schwartz’ Portrait Value Questionnaire (PVQ-21). To determine which values may be transmitted within families, we used a correlation analysis and pseudo dyad analysis that allows for the estimation of a baseline likeness between all tested subjects and consequently makes it possible to determine if similarities between actual family members are greater than chance. We also assessed whether different strategies of measuring similarity between family members render different results, and checked whether resemblances in family dyads are influenced by child’s and parent’s gender. Reported similarities were interpreted in light of the evolutionary and the value salience perspective.Keywords: intergenerational differences in values, gender differences, pseudo dyad analysis, transmission of values
Procedia PDF Downloads 498