Theses (Faculty of Science and Technology)
Állandó link (URI) ehhez a gyűjteményhez
Theses collection of the XX department/institute. The collection was started in 2017.
At the University of Debrecen, in accordance with the 2022 amendment to the 2011 Higher Education Act, student theses are only accessible from devices connected to the University's Eduroam WiFi network or from a university IP address.
“The thesis or diploma work of a student who has successfully passed the final examination shall be stored in full in the academic system of the higher education institution, and a record shall be maintained thereof. The stored theses and diploma works – with the exception of parts classified as confidential in accordance with the relevant legislation – must be made accessible and searchable without restriction through the academic system.” Further info on the National Higher Education Act in Hungarian: Felsőokt. tv. (új) - 2011. évi CCIV. törvény a nemzeti felsőoktatásról - Hatályos Jogszabályok Gyűjteménye.
Böngészés
Theses (Faculty of Science and Technology) Cím szerinti böngészés
Megjelenítve 1 - 20 (Összesen 744)
Találat egy oldalon
Rendezési lehetőségek
Tétel Korlátozottan hozzáférhető A 10 Year Statistical Analysis of Heavy Metal in River and Sediment in River Tisza, HungaryBabar, Nayna; Czédli, Herta; DE--Természettudományi és Technológiai Kar--Biológiai és Ökológiai IntézetIn course of our research, we did 10-year statistical analysis of heavy metals in Tisza river, Szolnok from 2010-2020. In doing so, we measured As, Zn, Hg, Cd, Cr, Mn, Ni, Pb, Cu, Fe from Tisza river. The sampling point was conducted at the Szolnok road bridge (335.5 TKM) from the small circle of the Tisza to the Hármas-Körös. The samples were collected from the period of 01/01/2010-03/12/2020. We did a time-series analysis on heavy metals.Tétel Korlátozottan hozzáférhető 15-membered rigid macrocyclic ligand for Mn2+ complexation: synthesis and coordination chemical characterizationBaghirova, Aghanana; Tircsó, Gyula; DE--Természettudományi és Technológiai Kar--Kémiai IntézetThe investigation of Mn²⁺ chelates as alternatives to Gd³⁺-based MRI contrast agents has gained significant attention due to their promising safety and performance profiles. My research focused on the synthesis and coordination chemistry of a novel 15-membered bipyridine-based macrocyclic ligand, 15-BPyN5. The ligand demonstrated excellent thermodynamic stability (log K_MnL = 13.44), high kinetic inertness, and favorable relaxivity properties (r1p/r2p = 3.60/6.60 mM⁻¹s⁻¹). Dissociation studies revealed slow exchange kinetics with Zn²⁺ ions, with half-lives of 79.0 and 28.7 hours at 25°C and 37°C, respectively, attributed to the rigid coordination environment provided by the bipyridine moiety. These properties highlight the potential of [Mn(15-BPyN5)] as a safe and effective MRI contrast agent. This work paves the way for developing non-toxic alternatives to gadolinium-based agents, offering improved safety and imaging performance.Tétel Korlátozottan hozzáférhető 2024 Update of Retro-Transposons in the Aspergillus and Penicillium Genera and Other Filamentous FungiAdil, Dastan; Michel , Flipphi; Michel , Flipphi; DE--Természettudományi és Technológiai Kar--Biotechnológiai IntézetRetrotransposons are mobile genetic elements that can generate genomic diversity, impacting gene expression and genomic stability. This thesis investigates the role of Copia-type retrotransposons, specifically Ty1 elements, in filamentous fungi like Aspergillus niger and Penicillium chrysogenum, focusing on their evolutionary and biotechnological significance. The study examines the structural characteristics, integration patterns, and functional impacts of AniTA2, a Copia retrotransposon identified in A. niger, with attention to its influence on genes linked to industrially relevant traits. Further, it discusses the application of Ty1 retrotransposons in industrial strain development, highlighting both their potential to enhance fungal strains and the challenges posed by genomic instability. The research concludes with future possibilities for using genome-editing tools like CRISPR/Cas9 to harness Ty1 elements safely for fungal biotechnology.Tétel Korlátozottan hozzáférhető 33 MVA DISTRIBUTION GRID FOR A NIGERIAN TOWNSHIP USING MEDIUM VOLTAGEMaduagwu, Osinaka; Kosa, Janos; DE--Természettudományi és Technológiai Kar--Fizikai IntézetThe power sector is the backbone of any thriving economy, providing the necessary energy for industrial, commercial, and domestic activities. In Nigeria, as in many developing nations, the power sector has been marred by persistent challenges, hindering the nation's economic growth and development. This dissertation seeks to delve into the intricate workings of the 33 MVA distribution grid in Nigeria, examining its role in the broader context of the nation's power sector, and proposing strategic interventions to address the prevailing issues. Nigeria, with its rapidly growing population and expanding economy, faces a continuous struggle to meet the escalating demand for electricity. The 33 MVA distribution grid plays a pivotal role in the final stage of the power supply chain, distributing electricity to end-users across various regions. However, despite the significance of this grid, there are systemic challenges that have hampered its effectiveness. In this report we are going to have an overview of how I conducted my thesis research report with the help of my supervisor Dr János Kosa. In my research report, we divided it into five main segments of which I wrote a detailed description of each segment to give an idea of what we are working with and how it all builds up together eventually. The following are the five main segments are listed below: 1. Show the Nigerian power grids. 2. Direction of development in Nigeria. 3. Design a medium voltage grid. 4. Calculation of the grid. 5. Applied switch gears in planned system.Tétel Korlátozottan hozzáférhető 3D analysis of the reaction products in Co2Si/Zn solid state diffusionTamel, Doga; Cserháti , Csaba; DE--Természettudományi és Technológiai Kar--Fizikai IntézetIn this thesis, a comprehensive investigation is conducted into the solid-state reaction between cobalt-disilicide (Co2Si) and solid zinc (Zn), with particular focus on the formation of periodic layered microstructures. The interaction between Co2Si and Zn is examined at 390°C, and samples are annealed for various durations to study the development of alternating layers. The reaction zone is characterised using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). Additionally, 3D imaging and analytical mapping are presented to provide a detailed visualisation of the reaction dynamics.Tétel Korlátozottan hozzáférhető A FIRST STEP IN ASSESSING THE DIATOM-BASED ECOLOGICAL STATUS OF INTERMITTENT STREAMS IN THE CARPATHIAN BASINESTHER, SHAMIM; Edina Kundrát-Simon, Viktória B-Béres; DE--Természettudományi és Technológiai Kar--Biológiai és Ökológiai IntézetExtreme weather events such as prolonged droughts or flash floods are currently the most obvious signs of climate change. These disturbances are causing significant environmental stress to the wetland and aquatic communities. In the last century, the average temperature in the Carpathian Basin has increased by approximately 1°C. All of these alterations had a significant impact on the small streams, resulting in a typological shift in many of them: streams that had a permanent water supply became intermittent waters. In recent years, our research group has been studying the effects of stream drying on benthic algal assemblages in small watercourses in the Carpathian Basin. Here, we focus on the differences in diatom indices between (i) intermittent and permanent lowland streams and (ii) different phases of drying such as flowing, standing and dry phasesTétel Korlátozottan hozzáférhető A genetical and oenological analysis of some interspecific hybrids with recombinant and nonrecombinant mitochondrial genomesKumagai, Yukino; Antunovics, Zsuzsa; DE--Természettudományi és Technológiai Kar--Biológiai és Ökológiai IntézetThe interspecies hybrids of Saccharomyces cerevisiae and Saccharomyces uvarum have the possibility to overcome some issues, which wineries face, like the condition changes due to climate change or changes in client demand. In this research, the results indicated that the hybrids are polyploid, which means they have chromosome sets from their parental strains by karyotyping. Also, it was confirmed that some of them have recombinant mitochondrial DNA due to the result of RFLP. With some physiological tests, heterosis is confirmed based on the results, which demonstrate better traits of the hybrids compared to the parents. For example, the hybrids could undergo fermentation with more various sugars, or grow more efficiently under cold temperatures. Additionally, there are some differences between non-recombinant and recombinant mitochondrial DNA contained strains, such as different fermentation rates with disaccharide sugars, or the growth test with glycerol under warmer and colder temperatures. However, overall, the significant differences were not able to be observed in the physiological tests between non-recombinant and recombinant mitochondrial DNA-containing strains. Therefore, further research is required to understand the importance of mitochondrial DNA recombination in wine industry applications.Tétel Korlátozottan hozzáférhető A Novel Approach Utilizing Polylactic Acid and Chitosan for Enhanced Shelf Life and Sustainability.Uurtsaikh, Tselmegzaya; Norbert , Ág; DE--Természettudományi és Technológiai Kar--Biotechnológiai IntézetBiopolymers, such as chitosan and polylactic acid (PLA), are being thought of more and more as alternatives to synthetic polymers because they are better at being renewable and biodegradable. Reinforcement techniques like grafting and mixing are being used to further enhance their properties. One of the best things about PLA is that it is easy to get, biodegradable, flexible, and can be strengthened with different natural fibers and fillers. Bioplastics are being explored as viable alternatives to traditional synthetic plastics, in light of international agreements concerning plastics.Tétel Korlátozottan hozzáférhető A Quick Study on The Basics of Dynmaical Fields and Their PotentialsABDELRAZEQ, ALHASAN; Trócsányi , Zoltán; DE--Természettudományi és Technológiai Kar--Fizikai IntézetAmong the most compelling topics within this discipline are the dynamics of cosmological fields and the enigmatic forces driving the universe’s accelerated (or decelerated) expansion, commonly attributed to dark energy. This thesis embarks on a systematic study of dynamical fields, delving into their mathematical formulations, physical interpretations, and cosmological implications.Tétel Korlátozottan hozzáférhető A study and simulations of short interest rates and some effects on the market instruments using Vasicek ModelSukkar, Izzat; GÁLL, József; DE--Természettudományi és Technológiai Kar--Matematikai IntézetStudying the movements of short interest rates is a very important research field. Almost all banks and investment institutes borrow or lend money with floating interest rates. Thus, this study is essential to measure the risk and hedge it or to speculate a possible gain in the future. In this work we will focus on researching the short interest rates movements using Vasicek model and review some other models. Simulations for the interest rates and market instruments are presented using the Vasicek model in R.Tétel Korlátozottan hozzáférhető Accumulation and translocation of metals in Sudan grass during a 3-month-long field experimentMunuhe, Esther; Tőzsér, Dávid; DE--Természettudományi és Technológiai Kar--Biológiai és Ökológiai IntézetHeavy metal accumulation in plants is a critical aspect of phytoremediation strategies aimed at mitigating environmental pollution. A study was conducted in which we investigated the heavy metal accumulation in Sudan grass ((Sorghum bicolor (L.) Moench × Sorghum sudanense (Piper) cultivated in a contaminated area located in Lovász-zug. We monitored metal accumulation in the roots, stems and leaves to assess their remediation potential. Through analysis, we identified notable variations in the accumulation capacity of different metals within the plant organs with time. Based on the results obtained, our study concluded Sudan Grass as a tolerant plant species in soils with low to moderate levels of contamination. The main depository organ of Sudan grass is the root. It can be effectively utilized to phytoremediate heavy metal contaminated soils through extraction, stabilization and transfer processes in the plant organs. The findings prospects Sudan grass as a promising candidate for phytoremediation.Tétel Korlátozottan hozzáférhető Accumulation and translocation of metals in Sudan grass during a 3-month-long field experimentMunuhe, Esther; Tőzsér, Dávid; DE--Természettudományi és Technológiai Kar--Biológiai és Ökológiai IntézetHeavy metal accumulation in plants is a critical aspect of phytoremediation strategies aimed at mitigating environmental pollution. A study was conducted in which we investigated the heavy metal accumulation in Sudan grass ((Sorghum bicolor (L.) Moench × Sorghum sudanense (Piper) cultivated in a contaminated area located in Lovász-zug. We monitored metal accumulation in the roots, stems and leaves to assess their remediation potential. Through analysis, we identified notable variations in the accumulation capacity of different metals within the plant organs with time. Based on the results obtained, our study concluded Sudan Grass as a tolerant plant species in soils with low to moderate levels of contamination. The main depository organ of Sudan grass is the root. It can be effectively utilized to phytoremediate heavy metal contaminated soils through extraction, stabilization and transfer processes in the plant organs. The findings prospects Sudan grass as a promising candidate for phytoremediation.Tétel Korlátozottan hozzáférhető Accumulation patterns of metals in selected plant species - meta-analysisYelamanova, Ayash; Edina Kundrát-Simon, Edina; DE--Természettudományi és Technológiai Kar--Biológiai és Ökológiai IntézetThe study investigates the concentration and accumulation of heavy metals in amaranth plant tissues. The results indicate that the accumulation pattern of metals is different. The study also demonstrates that heavy metals were translocated from soil to plant organs. The Bioaccumulation Factor (BAF) was calculated for evaluation of the plants accumulation potential. Therefore, it can be dangerous to consume amaranth plants grown in polluted soil, because they greatly absorb much of these toxic metals.Tétel Korlátozottan hozzáférhető Accuracy Assessment of Airborne-Based Photogrammetry using UAVOyewole, Eriifeoluwa; Szabó, Gergely; DE--Természettudományi és Technológiai Kar--Földtudományi IntézetAccuracy assessment using unmanned aerial vehicles (UAVs) involves evaluating the accuracy and precision of the data collected through photogrammetric methods. This can be done by comparing the UAV data to a ground truth dataset, such as GPS or survey data. The accuracy assessment process involves establishing ground control points (GCPs) to ensure accurate positioning, and then comparing the UAV data to the ground truth data through statistical analysis. This statistical analysis includes calculating square values, absolute vertical difference, mean, standard deviation, and root mean square error (RMSE) values. The results of the accuracy assessment is used to draw conclusions about the validity of the photogrammetric method used in the study and to provide recommendations for future research or applications.Tétel Korlátozottan hozzáférhető Accuracy constraints of different UAV sensor data of a landslide survey in HungaryNkunzi Rugamba , Fabrice; Bertalan, Laszlo; DE--Természettudományi és Technológiai Kar--Földtudományi IntézetThis study is about using modern technology to study and measure landslides, which are very dangerous events where rocks, soil, or mud slides down hills or mountains. Landslides can cause serious problems. Because they destroy homes, roads, farms and sometimes even take people’s lives. In many places around the world. These particular events they often happen mostly during heavy rain or because of different human activities like farming, deforestation and poor building methods. This topic was chosen in order to solve real-life problem in my country Rwanda and to gain skills in using smart technology to keep people safe. The study has several goals like how to detect landslide using LIDAR technology and different methods for analyzing results, get real results, and reduce landslide impact using remote sensing and 3D point cloud technology. This study uses remote sensing technology like LIDAR. INSAR and UAVs. These tools allowed the scanning from the sky without needing to go to dangerous place. Lidar uses laser beams to measure the land’s shape. Drones take many pictures, and special software is like Agisoft Metashape turns these images into 3D models. The study was done into steps where, the first step was fly the drone over the study area to take many high-quality pictures. These pictures were cleaned and processed to remove vegetation so that the land could be seen clearly. Then LIDAR and structure from motion (SFM) method were used to create 3D point cloud. Millions of small points and these points shows the land’s surface very Cleary. These point clouds were turned into digital elevation models (DEMs). DEMs are 3D maps that show the height and shape of the land. Finally, software’s like SAGA GIS, Arc GIS, Cloud compare, QGIS and past were used to analyze and get Statistical results and basic terrain analysis.Tétel Korlátozottan hozzáférhető Acoustic Emission During Structural Transformation in TWIP SteelsGuliyeva, Mehin; Dároczi, Lajos; DE--Természettudományi és Technológiai Kar--Fizikai IntézetThis thesis investigates the acoustic emission (AE) behavior during deformation of FeMn(Cr) steel. The primary objective of this study was to correlate AE signals with the stress-strain curve of the deformation prcess. A combination of uniaxial tensile testing and in-situ acoustic emission measurements was employed to capture real-time AE and simultaneous stress-strain data. Optical microscopy and scanning electron microscopy (SEM) were used to get additional microstructural informations and determine the chemical composition. This research offers a thorough exploration of the acoustic emission phenomena in TWIP steels, highlighting how AE can serve as an effective tool for real-time monitoring of material behavior during mechanical testing.Tétel Korlátozottan hozzáférhető Acute Exercise-Induced Modulation of NOD-like Receptors (NLRs) Expression in Skeletal MuscleElsayed, Eman Abdallah Elsayed; Benkő, Szilvia; Eduárd, Bíró; DE--Természettudományi és Technológiai Kar--Biológiai és Ökológiai IntézetNod-like receptors (NLRs) are part of the innate immune system, but they are also found in many other cell types, and their role in skeletal muscle remains largely underexplored. To address this, we developed a reproducible treadmill-based acute exercise model in mice, conducted at Zeitgeber Time 16 (ZT16) to align with their active nocturnal phase. Muscle samples were collected from the gastrocnemius at 4-, 8-, and 24-hours post-exercise to capture immediate and delayed gene expression responses. The aim of this thesis was to investigate the role of NLRs in muscle function by assessing how acute exercise affects the expression of NOD1 and NOD2 in skeletal muscle and comparing their expression between males and females. Gene expression analysis using qPCR confirmed that the early response gene NR4A3 was significantly upregulated at 4 hours in both male and female mice, indicating successful activation of exercise-responsive pathways. NOD2 expression was significantly elevated at 8 hours post-exercise in males only, suggesting a sex-specific activation possibly linked to cellular stress and the release of DAMPs following muscle damage. The downstream signalling molecule RIPK2, which is activated by NOD2, was also upregulated in males at 24 hours, further supporting this pathway's involvement. In contrast, NOD1 expression remained unchanged in both sexes. These results suggest that acute exercise triggers sex-specific molecular responses in skeletal muscle, particularly involving NOD2 signalling pathways. The study highlights the importance of considering biological sex in experiments investigating immune and exercise-related gene expression in skeletal muscle tissue.Tétel Korlátozottan hozzáférhető Adsorption of bovine serum albumin on silica aerogel surface: Detailed kinetic model of the systemRanga, Madalina; Forgács, Attila; DE--Természettudományi és Technológiai Kar--Kémiai IntézetIn this thesis, I investigated the interaction of bovine serum albumin (BSA) and mesoporous silica aerogel, which can be used as a potential drug carrier and tissue scaffold in the biomedical field. Since bovine serum albumin is similar to human serum albumin (HSA), it is suitable for modeling the aerogel-protein system.During the experiments, BSA adsorption was observed on the mesoporous silica surface, which was confirmed by light microscopic examinations. The obtained UV-vis kinetic data were corrected using the Dual-Wavelength Method of background correction, to eliminate the background caused by the turbidity of the aerogel suspension. The results suggest that a complex process occurs after the injection of BSA solution into the aerogel suspension.Tétel Korlátozottan hozzáférhető Advanced glycation end productsDat, Pham Thai; Barna, Teréz; DE--Természettudományi és Technológiai Kar--Biotechnológiai IntézetAdvanced glycation end products (AGEs) are a heterogeneous group of compounds formed by non-enzymatic interactions between the carbonyl groups of reducing sugars and free amino groups of proteins, lipids, or nucleic acids. Browning, fluorescence, and protein cross-linking may occur as a result of the Maillard process, which produces AGEs. AGEs can be produced in the body, but they can also come from outside the body, such as smoking and certain foods. The concept of AGEs receptor - RAGE is mentioned. In this thesis research, the theory on AGEs classifications, absorption, and toxic AGE will be reviewed. In addition, the contents of AGEs in food and beverages, the AGEs reduction in food processing will be discussed.Tétel Korlátozottan hozzáférhető Allogeneic reactions of pre-activated CAR T cells on target-negative cancer cellsLi, Artyom; Nagy, Lőrinc; DE--Természettudományi és Technológiai Kar--Biotechnológiai IntézetT cells were isolated from 2 donor's PBMCs and transduced with HER2-CAR construct. The study evaluated the cytotoxic activity of HER2-CAR T cells against three cell lines: HER2-negative MDA cells and HER2-positive MDA-HER2 and MDA-HER2-231 cells. The results demonstrated significant cytotoxicity against MDA-HER2 cells, confirming the specificity of HER2-CAR T cells, while no cytotoxic effects were observed for HER2-negative MDA cells and MDA-HER2-231 cells, which had low expression of HER2 antigen. It implies that HER2-CAR T cells are unlikely to target healthy tissues with low expression of HER2. The same pattern was observed in the case of pre-activated T cells, and regardless of IL-2 and the donor of T cells.