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
legfrissebb feltöltések
Megjelenítve 1 - 20 (Összesen 801)
Tétel Korlátozottan hozzáférhető TEMPERATURE SENSOR CALIBRATION USING ARDUINO NameEhizuenlen , Emmanuel; Harasztosi , Lajos; DE--Természettudományi és Technológiai Kar--Fizikai IntézetThis thesis presents the design and implementation of a temperature control system that measures, displays, and regulates temperature using an Arduino-based embedded platform. The system employs a DS18B20 digital temperature sensor for accurate thermal measurement, a potentiometer for user-defined setpoint selection, and a MOSFET-driven heating element for actuation. Real-time data is displayed on an OLED screen, while the underlying control loop adjusts output power through PWM to maintain the desired temperature. Comprehensive testing demonstrates stable sensor performance, reliable switching behaviour, and effective closed-loop regulation. The project highlights the practical integration of sensing, actuation, and control within a low-cost, microcontroller-based environment suitable for educational, experimental, and small-scale calibration applications.Tétel Korlátozottan hozzáférhető Superconductors in energy systemChinoera, Tinomudaishe Elisha; Kosa, Janos; DE--Természettudományi és Technológiai Kar--Fizikai IntézetIn this thesis superconductors are the main topic of discussion. We look at their general properties and applications the go deeper into the application at SFCLs.Tétel Korlátozottan hozzáférhető DESIGN AND IMPLEMENTATION OF A TERRAIN-ADAPTIVE ROBOTIC PLATFORM USING MEMS IMU FOR ENHANCED MOTION CONTROL AND TERRAIN CLASSIFICATIONMusawar, Saad Bin; Trencsényi , Réka Eszter; DE--Természettudományi és Technológiai Kar--Fizikai IntézetThis thesis presents a novel approach to enhancing robotic autonomy through the design and simulation of a terrain-adaptive 4WD platform utilizing a low-cost MEMS Inertial Measurement Unit (IMU). Addressing the critical challenge of reliable navigation across diverse, unstructured environments, our work develops a robust framework for adaptive motion control and real-time terrain classification. Within Webots R2025a, the system first implemented adaptive control, dynamically adjusting wheel velocity based on IMU tilt and calculated slip, achieving a 28% reduction in average wheel slip on bumpy terrain. Subsequently, a real-time classification algorithm, fusing IMU vibration characteristics with slip data, demonstrated a 92% accuracy in distinguishing between simulated grass and asphalt surfaces. These capabilities enable the robot to intelligently modify its locomotion parameters, significantly improving stability and traction. Our core contribution lies in validating that accessible IMU technology, combined with sophisticated filtering and a rule-based decision architecture, provides an efficient and scalable solution for advanced robotic mobility. This research offers a strong foundation for developing more resilient autonomous systems vital for applications in challenging, real-world scenarios.Tétel Korlátozottan hozzáférhető Designing a Solar system for the Energy supply of a Residential House.Agbenu, Prince Sena; Trencsényi, Réka Eszter; DE--Természettudományi és Technológiai Kar--Fizikai IntézetTo increase household energy independence, lessen dependency on the national grid and forecast possible financial and environmental benefits, I designed and assessed a home solar photovoltaic (PV) system for this project. With the integration of both the block and circuit diagrams, the system’s structural and electrical architecture have been clearly illustrated, highlighting the energy conversion pathway from solar irradiation to AC distribution and grid interconnection. I modelled the system's performance using the OpenSolar design platform and found that the estimated energy output closely matched the anticipated production metrics, with daily variances of less than 2%.Tétel Korlátozottan hozzáférhető PLC-Based Water Pumping and Distribution System for IrrigationAhmed, Tamim; Sandor , Misak; DE--Természettudományi és Technológiai Kar--Fizikai IntézetThis thesis presents the design and implementation of a PLC-based water pumping and distribution system in a dual-field agricultural irrigation setup to improve its water-use efficiency, reliability, and automation compared to manual irrigation methods. The work starts with an overview of conventional irrigation types and materials, followed by the definition of functional and non-functional requirements for an automated, multi-zone, sensor-driven system with strong safety and environmental considerations. The controller chosen is Eaton easy-E4-DC-12TC1 with the addition of expansion modules, interfaced with soil moisture sensors, level switches, flow sensors, pumps, solenoid valves, and protection devices, all arranged through detailed I/O lists and ladder logic. The work includes the project's virtual simulation done with tools like Factory IO, TIA/Proteus-style tools; a physical test environment; and the development of HMI, web visualization, and SCADA interfaces using Modbus TCP for real-time monitoring, control, and remote access. Implemented are zone-based irrigation strategies, delayed starts, rain-based automatic shutdown, and tank level alarms as protection for equipment, prevention of over-irrigation, energy, and water consumption. The thesis concludes that the system successfully meets its objectives and suggests future enhancements like advanced sensor technologies, wireless/IoT integration, and AI-driven sensors for irrigation optimization for more precision agriculture.Tétel Korlátozottan hozzáférhető Solar Energy Systems Protection by SuperconductingOkyere Dapaah, Solomon; Kósa, János Árpád; DE--Természettudományi és Technológiai Kar--Fizikai IntézetThe thesis is a study of how Superconducting technology, especially the High Temperature Superconducting Magnetic Energy Storage (HTSMES) and Superconducting Fault Current Limiters (SFCLs) can be used to improve the protection, reliability, and stability of grid-connected solar photovoltaic (PV) systems. It simulates and designs a superconducting protection system on a 10 MW, 15 kV DC solar plant indicating that HTSMES has the ability to localize fault currents in a short period of time, and short-circuit peak currents are less than half that of systems without superconducting protection. Superconducting technology is integrated to reduce voltage sags by more than 47 percent and enable a fast voltage recovery in less than 0.25 seconds, reducing power fluctuations and also allowing reactive power assistance in the form of inverters. The report incorporates design calculations of SFCLs with the consideration of a particular superconducting wire and simulation of PV array-grid connection and power converters to have strong functionality of the system and to be in accordance with the grid requirements. The simulation findings indicate that the SMES offers rapid response to faults, large fault current limitation, voltage stability, and improved overall quality of power over the traditional systems that do not have superconducting protection. The thesis concludes that superconducting protection systems are practical and very useful in future large scale renewable energy networks, which are better in fault management, system reliability and integration of renewable energy.Tétel Korlátozottan hozzáférhető PLC-Automated Step Up Conveyor System For Bottle CappingSalah , Salah; Sandor, Misak; DE--Természettudományi és Technológiai Kar--Fizikai IntézetThis project showcases the operation of a PLC-Automated Step-Up Conveyor System for Bottle Capping. It demonstrates how programmable logic controllers (PLCs) can be used to automate a complete filling, capping, and bottling process, modeled as a simplified version of an industrial production line. The project focuses on explaining the full automation cycle—from filling to capping—along with the step-up conveyor mechanism. It also details the role and function of each electrical component involved. It highlights how sensors, actuators, and motors etc. are integrated through PLC programming to achieve efficient operations. One achievement at the core of this work involves a step-up conveyor mechanism that assists in minimizing downtime by redirecting bottles during machine delays or stoppages.Tétel Korlátozottan hozzáférhető APPLICATION OF HIGH TEMPERATURE SUPERCONDUCTORS IN ELECTRICAL PROTECTIONUzu, Ugochukwu; Arpad, Kosa; DE--Természettudományi és Technológiai Kar--Fizikai IntézetThis Thesis study shows how high-temperature superconducting technology could positively change the way electrical protection works, making systems stronger and more effective. As these ideas move from research to real-life use, HTS-FCLs will play a huge role in developing the future of reliable power grids.Tétel Korlátozottan hozzáférhető PLC-BASED SMART HOME CONTROL SYSTEM WITH INTEGRATED SAFETY AND COMFORTBerrami, Anas; Sándor, Misák; DE--Természettudományi és Technológiai Kar--Fizikai IntézetThis thesis demonstrates a PLC-based smart home. Two modes auto and manual are the main paths to control the house. When auto is chosen then lighting, heating and cooling, ventilation... are controlled automatically based on sensors and PLC programmed logic. User can at any time use manual commands to override the auto commands. User can also control the house through the designed HMI screen.Tétel Korlátozottan hozzáférhető Simulation and Design of Audio Power AmplifierEmeka Ali, Faithful; Harasztosi, Lajos; DE--Természettudományi és Technológiai Kar--Fizikai IntézetMy thesis work involved the whole process of creating an OPA548 power amplifier. In the body of my thesis work, I started with a brief history, note on amplifier quality parameters, and description of the amplifier to be created. I then discussed extensively on the physical and chemical processes which I performed in the laboratory to create and assemble the PCB. The next stage was the testing and measurement of the amplifier parameters to ensure all parts work correctly. Finally, I compared the measured results and the simulated result.Tétel Korlátozottan hozzáférhető Synthesis of Dithioacetal-β,β-Digalactosides as Potential Lectin LigandsAziz, Nazish; Anikó , Borbás; Ghanem Kattoub, Rasha; DE--Természettudományi és Technológiai Kar--Kémiai IntézetThis work describes the synthesis of novel dithioacetal-digalactoside derivatives as potential inhibitors of Pseudomonas aeruginosa LecA lectin. Pseudomonas aeruginosa is a WHO-classified priority pathogen that uses lectins for biofilm formation, contributing to antibiotic resistance. A library of bivalent and tetravalent thiogalactoside compounds was successfully synthesized through a two-step process involving thioacetalization with aromatic aldehydes followed by Zemplén deacetylation. The synthesized compounds exhibited good to excellent yields and were fully characterized by NMR spectroscopy and mass spectrometry. These sulfur-containing glycomimetics offer enhanced stability compared to natural carbohydrates and represent promising candidates for anti-biofilm therapeutic strategies against antibiotic-resistant bacterial infections.Tétel Korlátozottan hozzáférhető NMR and MS study of the interaction between [(η6-p-cym)Ru]2+ and the ImPropHpH ligandUllah, Irfan; Buglyó, Péter; Ildikó Kovács , Nóra; DE--Természettudományi és Technológiai Kar--Kémiai IntézetMy thesis presents a clear and insightful investigation into the coordination chemistry between the organoruthenium cation and the ambidentate ligand ImPropHpH. I successfully address a major gap in previous research by clarifying the slow and poorly understood interaction between this ligand and ruthenium. Through the combined use of ¹H NMR and ESI-MS, I provide strong, well-interpreted evidence for the formation of both mono- and dinuclear complexes. The consistency between the NMR data and the mass-spectrometric results reinforces the reliability of my structural conclusions. My work is organized logically, demonstrates solid technical understanding, and effectively communicates complex chemical behavior. Overall, the thesis contributes meaningful new characterization that will support the future design of ruthenium-based anticancer agents.Tétel Korlátozottan hozzáférhető Computational Study on the Mechanism of Hydrogen Storage in Hydroborane SystemsNurbanu, Koc; Hollóczki, Oldamur; DE--Természettudományi és Technológiai Kar--Kémiai IntézetThe computational paper investigated the H2 release from ammonia borane (NH3BH3) using an iridium catalyst via Density Functional Theory (DFT). The study found the dehydrogenation reaction to be exothermic. Interestingly, a detailed potential energy surface scan showed no transition state barrier for the H2 abstraction step, indicating a barrier-less reaction under the simulated conditions. This work provides foundational data for future efforts to improve catalysts for hydrogen storage systems.Tétel Korlátozottan hozzáférhető Impact of Manganese Ion Contamination on Fungal Morphology and Organic Acid Yields in Citric Acid and Itaconic Acid Production.Kumah, Israel; Bíró, Vivien; DE--Természettudományi és Technológiai Kar--Biotechnológiai IntézetThis paper examines the impacts of fungal morphology and the yield of citric acid by Aspergillus niger and itaconic acid by Aspergillus terreus under the influence of manganese ion (Mn2+) contamination. The study indicates that the presence of manganese ions at concentrations above critical threshold can interfere with the fungal morphology and organic acid production during the fermentation of citric acid by Aspergillus niger and itaconic acid by Aspergillus terreus. Below the threshold, both fungi can form a favorable pellet morphology, leading to high organic acid yields. On the other hand, excess manganese ion concentrations induces a less productive filamentous growth which lowers the yields of the organic acids. This research establishes that controlling the concentration of manganese is necessary in the production of organic acids in industries. In general, the control of Mn2+ contamination can be considered among the best approaches to reducing cost and increasing the efficiency of industrial fermentation.Tétel Korlátozottan hozzáférhető The Effect of Manganese-Phosphate Interaction on the Fermentation Process of Aspergillus terreus.Affor , Lisvin Edinam Konings; Bíró, Vivien; DE--Természettudományi és Technológiai Kar--Biotechnológiai IntézetItaconic acid (IA) is a sustainable platform chemical with growing industrial relevance, produced mainly by Aspergillus terreus under controlled nutrient conditions. This study evaluates the effects of manganese (Mn²⁺) and phosphate (PO₄³⁻) on IA production from glucose in submerged fermentation. Under trace Mn²⁺ conditions, IA reached 66.52 g/L at 192 h with an 84.76% molar yield, indicating highly efficient carbon conversion. In contrast, excess Mn²⁺ (30–200 μg/L) reduced IA titers to 50 g/L and promoted increased biomass formation and dispersed hyphal morphology. Phosphate supplementation alone also decreased IA yield by shifting metabolism toward biomass, while combined Mn²⁺ PO₄³⁻ treatment caused an almost complete loss of IA production with dry cell weight reaching 40 g/L. These results demonstrate that only under trace Mn²⁺, controlled phosphate levels, and proper fungal morphology can IA production reach its maximum potential, providing valuable guidance for industrial fermentation optimization.Tétel Korlátozottan hozzáférhető The Role of the Second Alternative Oxidase Gene in Aspergillus nigerKattah, Sandra Seyram; Márton, Alexandra; DE--Természettudományi és Technológiai Kar--Biotechnológiai IntézetThis thesis investigates the role of the second alternative oxidase gene, aoxB, in Aspergillus niger, one of the most researched filamentous fungi for industrial citric acid production. The hypothesis states that a wild-type strain with functional aoxB and aoxA is a more productive strain than a mutant strain with a non-functional aoxB. A series of fermentation experiments, morphology experiments and growth characterization experiments in submerged and solid state revealed that aoxB presence does not significantly impact productivity under acid production settings or submerged fermentation morphology but does impact metabolic diversity in low carbon conditions. The aoxB mutant strain exhibited varying colony morphology, reduced radial growth on solid state media, and increased biomass generation at the cost of citric acid. Therefore, aoxB does not play a significant role in citric acid production but instead in continued generation and survival under stressful conditions. These results bear significance to those studying mitochondrial respiratory diversity as well as applicability to biotechnological endeavours in the field.Tétel Korlátozottan hozzáférhető Temporal analysis of forest cover change using random forest classification (1995-2020)Amanpoor Gharaei, Samaneh; Szábo, Szilard; DE--Természettudományi és Technológiai Kar--Matematikai IntézetIn Europe, more than 39 percent of the land is covered by forests; also, in Hungary, 21 percent of the land is covered by forests, with significant variations in their distribution ( European Environment Agency, 2018). The city of Debrecen, which is in the eastern part of Hungary, has experienced urban development and land transformation during the past decades. As one of the largest cities in Hungary, Debrecen’s forest is facing pressure from urbanization, agricultural activity, and the expansion of infrastructure. Understanding the forest cover dynamics in this region is essential for urban planning and forest management. In this study, we will analyze how much forest cover has changed.Tétel Korlátozottan hozzáférhető Investigating the Role of Xylose Transporters in Aspergillus niger.ANDOH , ANTOINETTE ARABA; Bíró , Vivien; DE--Természettudományi és Technológiai Kar--Biotechnológiai IntézetThis thesis aims to determine the physiological role of D-xylose transporters in Aspergillus niger and their impact on sugar uptake efficiency. The study compares the fermentation profiles of a wild-type strain against mutant strains with transporter gene deletions under low and high xylose concentrations. At the low concentration, the mutant strains displayed a significant delay in substrate depletion compared to the wild type, indicating that missing transporters are crucial for high-affinity uptake. Under high conditions, the wild type exhibited a rapid acceleration uptake after 24 hours, whereas the mutants followed a slower, linear consumption pattern. Despite these delays, the mutant strains were eventually able to fully consume the xylose, suggesting the presence of alternative, unidentified transport pathways. The results conclude that while Aspergillus niger possesses redundant systems, the specific transporters studied are essential for optimizing fermentation speed and handling varying substrate levels.Tétel Korlátozottan hozzáférhető Machine Learning based land use classification and identification of driving factors in Google Earth EngineLi, Junyi; Abriha, Dávid; DE--Természettudományi és Technológiai Kar--Földtudományi IntézetThis thesis utilizes Google Earth Engine and machine learning to classify land use and analyze driving factors in Dalian, China, from 2000 to 2020. It employs a Random Forest algorithm on Landsat imagery to generate land use maps for four categories: agricultural land, vegetation, water, and built-up areas. Using Principal Component Analysis and Multiple Linear Regression, it identifies the primary drivers of land use change. The research demonstrates the effectiveness of cloud computing platforms for large-scale, long-term land use monitoring and provides a scientific basis for regional land management.Tétel Korlátozottan hozzáférhető Fermentation of Rhodococcus spp. for Biomass ProductionYavorska de Sousa Pires, Ekaterina; Biró, Vivien; DE--Természettudományi és Technológiai Kar--Biotechnológiai IntézetThis thesis focuses on the aerobic fermentation of Rhodococcus sp. with the aim of documenting the cultivation process and evaluating the strain's growth behavior under controlled conditions. The experimental work included the preparation of inocula in shake flasks, followed by cultivation in a 5 L fermenter and finally in a 150 L stainless-steel bioreactor. Throughout the fermentation, pH, dissolved oxygen, and biomass concentration were monitored to assess process stability and physiological activity. The culture showed steady growth and maintained conditions, reaching approximately 10 g/L of dry cell weight by the end of the batch. These findings confirm that the applied conditions supported efficient biomass formation at large scale.