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Öğe The effect of PWHT on the mechanical properties of HHA 500 armor steel welds(FEB 2025) Ertek Emre, Hayriye; Kece, Serkan; Kacar, Ramazan; Nohutcu, SametArmor steels are produced to protect against any explosions and armed attacks. In addition, high hardness armor (HHA) steels have excellent ballistic properties due to their hardness and strength. Choosing the correct welding method and providing optimum heat input when joining armor steels is very important in order to obtain the desired properties. Additionally, unwanted residual stresses occur after welding. It can be relieved by post-weld heat treatments (PWHT). This research aims to investigate the effect of PWHT on the mechanical properties and microstructure of Bisalloy HHA500 armor steel welded with gas metal arc welding (GMAW). The Bisalloy HHA500 series armor steels were joined with the automated GMAW method at optimized welding parameters through preliminary experimental tests. After welding processes, PWHT was applied at 650°C for 1 hour. In order to determine the mechanical properties of both as-welded and PWHT joints, tensile, bending, and Charpy-notch impact tests were performed. The microstructure investigation and hardness measurements were carried out. As a result of PWHT, an increase in the Charpy-notch impact strength by 16% was detected. © IMechE 2025.Öğe Dynamic Response Analysis and Active Vibration Control of the Smart Sandwich Composite Plate With FGM Core Layers and MIMO FGPM Actuators and Sensors(MAR 2025) Aktas, Kerim Gokhan; Esen, IsmailThis article deals with the dynamic response analysis and active vibration control of the smart functionally graded material (FGM) composite core plate with FG piezoelectric material (FGPM) surface actuators and sensors. Considering a power law distribution, the mechanical and electrical material characteristics of the FGM and FGPM layers change continually along the thickness plane. The finite element method (FEM) and the first-order shear deformation theory (FSDT) are utilized in the modeling process for the FGM and FGPM layers. In the dynamic analysis, the dynamic response of the sandwich structure under the impact of sinusoidally distributed step load and the corresponding sensor voltage is obtained. To ensure that the simulations are accurate, the findings are compared with previously published research. To analyze the control efficiency of FGPM sensors and actuators on the FGM host structure, the linear quadratic regulator (LQR) controller is utilized. The sandwich structure is considered a multiple-input multiple-output system (MIMO), so sensors and actuators are placed at different locations on the plate surface. The modal strain energy method is utilized to find the appropriate location of the FGPM layers. According to the results of the analysis, it has been determined that piezoelectric material coefficients as well as mechanical properties are extremely important for obtaining optimum control performance from FGPM sensors and actuators. In addition, it is emphasized that active vibration control of FGM plates can be performed effectively with the proper selection of sensors and actuators and their accurate distribution on the plate. These results are expected to contribute to micro-electro-mechanical system (MEMS) sensor and actuator applications, soft robotics applications, and vibration protection and vibration damping applications of nanostructures.Öğe Investigation of The Morphological Characteristics of Cones and Seeds of The Scots pine (Pinus sylvestris L.) in Natural(2025) Seki, NagihanAim of study: The aim of this study is to investigate the morphological characteristics of Scots pine cones and seeds in a variety of natural populations. Area of study: The study was carried out in 12 different natural Scots pine populations in the Western Material and method: A total of 600 cone and 1727 seed samples were collected from 12 natural Scots pine populations. Multivariate Analysis of Variance and post-hoc test were used to investigate differences in cone and seed characteristics including cone length (cl), Acone diameter (cd), cl/cd ratio, ratio between populations. Main results: Cone and seed morphological characteristics of Scots pine individuals showed statistically significant differences between populations. The Dedemda & gbreve; (Tosya) population had the largest cones in terms of both diameter and length, while the K & imath;z & imath;lkaya (Yenice) and Kartalkaya (Alada & gbreve;) populations had the smallest cones. Research highlights: The protection of natural populations of Scots pine is very important, especially for the conservation of seed resources. This study provides important information about potential Scots pine populations in Northwestern T & uuml;rkiye.Öğe Experimental study on the thermal performance of hybrid nanofluid in a compact plate heat exchanger under the influence of a magnetic field(Elsevier, MAY 2025) Tekir, MutluThis study presents an experimental investigation into the thermal and hydrodynamic performance of a compact plate heat exchanger utilizing Fe3O4/water and Fe3O4–Cu/water hybrid nanofluids under the influence of an externally applied magnetic field (0.46 T). The effects of nanoparticle concentration, hybrid nanoparticle composition, and flow conditions on heat exchanger effectiveness and convective heat transfer were analyzed under laminar flow conditions (172 ≤ Re ≤ 400). The results indicate that while nanofluids enhance overall heat exchanger effectiveness compared to water, the effectiveness increased by up to 20 % for hybrid nanofluids in the absence of a magnetic field. However, the application of a magnetic field reduced effectiveness by up to 15 %. Similarly, the Nusselt number decreased by up to 12 % and the convective heat transfer coefficient declined by up to 10 % with increasing nanoparticle concentration, with higher concentrations (1.0 %) causing greater reductions due to elevated viscosity and suppressed flow mixing. The application of a magnetic field further reduces convective heat transfer performance by approximately 6–8 % for hybrid nanofluids, likely due to nanoparticle retention and local velocity reduction caused by the Lorentz force. These findings provide insights into optimizing nanofluid-based heat exchanger systems, emphasizing the need for careful selection of nanoparticle composition and magnetic field parameters to balance heat transfer performance and flow efficiency.Öğe Investigation of the Critical Buckling Temperatures and Free Vibration Response of Porous Functionally Graded Magneto-Electro-Elastic Sandwich Higher-Order Nanoplates with Temperature-Dependent Material Properties(Springer Nature, FEB 2025) Esen, Ismail; Aktaş, Kerim Gökhan); Pehlivan, FatihPurposeThis article aims to determine the critical buckling temperature and thermomechanical free vibration response of a porous functionally graded material (FGM) nanoplate sandwiched between porous magneto-electro-elastic (MEE) plate layers, taking into account temperature-dependent material properties.MethodsThe upper surface of the FGM host structure is considered zirconia (ZrO ), and the lower surface is stainless steel (SUS304). In addition, the MEE face layers are considered to be homogenous volumetric mixtures of cobalt-ferrite (CoFe O ) and barium-titanate (BaTiO ). It is assumed that the host structure's effective mechanical and thermal material properties are graded in the thickness direction according to the power law distribution. The effective mechanical, electrical, thermal, and magnetic properties of the face plates are obtained by the rule of mixture. This study was conducted using sinusoidal higher-order shear deformation theory (SHSDT) and nonlocal strain gradient elasticity theory (NSGT). Hamilton's theory is utilized to derive the equations of motion of sandwich nanoplates. Closed-form solutions are obtained by the use of Navier's method.ResultsParametric simulations are carried out to examine the effects of the power law index, nonlocal parameters, electric, magnetic, and thermal loads, porosity volume fraction, porosity distribution and volume ratio of CoFe O and BaTiO on the free vibration and buckling behavior of the nanoplate. The results of the simulations are compared with published works to verify the accuracy of the proposed method.ConclusionAccording to the analysis results, it is determined that the power law index, porosity ratio, porosity distribution function, temperature dependent properties, magneto-electro-thermo-mechanical loads and nonlocal factors significantly affect the thermomechanical behavior of the nanoplate.Öğe Frequency Regulation of Stand-Alone Synchronous Generator via Induction Motor Speed Control Using a PSO-Fuzzy PID Controller(MDPI, MAR 26 2025) Elhawat, Masoud; Altınkaya, HüseyinThis paper introduces a novel approach to frequency regulation in stand-alone synchronous generators by combining particle swarm optimization (PSO) with a Fuzzy PID controller. This study compares three control methods: a programmable logic controller (PLC)-based PID, a Fuzzy PID, and a PSO-Fuzzy PID controller. An experimental setup is implemented using real physical equipment, including an asynchronous motor, a synchronous generator, and various power and control components. The system is monitored and controlled in real-time via an S7-1215 PLC with the TIA Portal V17 interface, and the controllers are designed using MATLAB/Simulink. PLC-MATLAB communication is implemented using the KEPServerEX interface and the OPC UA protocol. The PSO-Fuzzy PID controller demonstrates superior performance, reducing overshoot, undershoot, and settling time compared to the other methods. These results highlight the effectiveness and real-time applicability of the PSO-Fuzzy PID controller for industrial frequency control, especially under varying load conditions and the nonlinear characteristics of the synchronous generator.Öğe Thermomechanical free vibration buckling of FG graphene-reinforced doubly-curved sandwich shells(Elsevier, 2025-01-31) Eroğlu, Mustafa; Koç, Mehmet Akif; Esen, İsmailThis study explores the thermomechanical free vibration and buckling behavior of doubly-curved sandwich shell structures with a core of FG graphene-reinforced foam and metal or ceramic face layers. Using Hamilton's principle and a Navier-type solution method, the governing equations and boundary conditions for simply supported, functionally graded doubly-curved shells are derived. The numerical results are validated through comparison with existing literature. The analysis focuses on the effects of the material grading index, foam void ratio, graphene volume fraction, side-to-thickness ratio, and temperature variations. Notably, it was observed that as R1 increases from α to 10α, the buckling temperature significantly decreases, highlighting a reduction in thermal stability with increasing radii or inverse correlation between R1 and R2. These findings reveal unexpected thermal instability trends that could influence future design considerations for high-temperature applications. This study provides novel insights into the thermomechanical behavior of advanced sandwich structures, offering valuable contributions to the field in light of evolving technological needs.Öğe Karabük Kent Konseyi ve 2023 Karabük vizyonu(Karabük Valiliği, 2010) Büyükgenç, ÖzcanKent Konseyleri, kent yaşamında; Kent vizyonunun ve hemşehrilik bilincinin geliştirilmesi, kentin hak ve hukukunun korunması, sürdürülebilir kalkınma, çevreye duyarlılık, sosyal yardımlaşma ve dayanışma, saydamlık, hesap sorma ve hesap verme, katılım ve yerinden yönetim ilkelerini hayata geçirmeye çalışan, kent ve yaşam kalitesini geliştiren, demokratik ve bağımsız kuruluşlardır.Öğe Effects of hot rolling on microstructures, wear and corrosion resistance of mo-ni-w p/m alloyed steels(Technical Faculty in Bor, 2024-11) Elkilani R.H.R.; Çuğ H.; Erden M.A.; Abushrenta H.; Albahlol O.; Cicek B.This study analyzes how hot rolling changes microstructure, tensile strength, wear, and corrosion behavior of Fe-0.55C3Mo-10Ni-0.5W alloy steel. The metal powders were pressed at 750 MPa pressure, and the cold-pressed samples were sintered for two hours at 5°C/min up to 1400°C in a mixed-gas environment of 90% nitrogen and 10% hydrogen. The steels produced were then hot rolled at 40% and 80% deformation rate. The microstructures demonstrate that MoC(N), WC(N), and MoWC(N) were produced and that the steels exhibited finer microstructures and better mechanical properties as the deformation rate increased. Wear decreased as the deformation rate increased. Furthermore, the the hot rolling method improved the corrosion resistance, as shown by the Tafel curve analysis. The greatest factor supporting the corrosion resistance was the increase in density value throughout the rolling process.Öğe Energy and exergy analysis of PV modules: Sustainable improvements through fin structure and spray cooling(Elsevier B.V., 2025-01-30) Ismael Ismael, Omar Rashid; Selimli, SelcukStudies in the literature focused on improving photovoltaic energy performance through spray or fin cooling have inspired this study to investigate the combined effect of these methods using a temperature-controlled, water-saving spray technique. The temperature-controlled spraying technique aims to improve energy efficiency through efficient cooling and reduced water loss. The effects of cooling a photovoltaic module with a fin structure and improving cooling by a spray system on energy performance were experimentally tested on three modules: PV₁ works without cooling, PV₂ uses a fin structure, and PV₃ includes both a fin structure and spray cooling. The temperatures of the PV₂ and PV₃ modules are 1.59 % and 4.59 % lower, respectively, as contrasted to the PV₁ module. PV₁, PV₂, and PV₃ modules had energy efficiency of 12.7 %, 14.10 %, and 14.93 %, respectively, and exergy efficiencies of 8.25 %, 11.25 %, and 14.86 %, respectively. The PV₂ and PV₃ modules had a higher energy efficiency of 1.40 % and 2.20 %, respectively, and a higher exergy efficiency of 3 % and 6.61 %, compared to the PV₁ module. The fin structure with spray cooling improved the availability of renewable energy. The sustainability index of PV₁, PV₂ and PV₃ modules are 1.09, 1.13 and 1.17, respectively, which shows that the cooling effect reduces irreversibility and environmental degradation.Öğe An additional value for the disposed wastes: An experimental and RSM optimization study based on the enhancement of waste plastic oil/diesel fuel blend with optimum B₂O₃ nanoparticles for cleaner emissions(Elsevier B.V., 2025-01-23) Uslu, SametIn the current study, the ability of waste cable pyrolysis oil (WCPO) and boron oxide (B2O3) nanoparticles to improve diesel engine response was evaluated. Firstly, WCPO was produced and 20 % was determined as the most suitable mixture ratio for diesel engines. Then, different amounts (20, 40, and 60 ppm) of B2O3 were added to the fuel mixture containing 20 % WCPO/80 % diesel to strengthen the negative aspects of WCPO. The addition of 20 % WCPO reduced BTHE by an average of 7.93 % and with the positive effect of the addition of 20 ppm B2O3, this reduction was increased to an average of 0.83 %. Furthermore, the addition of B2O3 nanoparticles decreased CO and HC emissions, whereas the addition of 20 % WCPO enhanced them. HC decreased by 27.18 % with 20 ppm B2O3, after increasing by an average of 5.61 % with WCPO20 compared to diesel. Likewise, for CO, there was a 67.96 % increase with WCPO20 and a 5.92 % drop with 20 ppm B2O3. However, response surface methodology (RSM) optimization was also carried out to determine the ideal concentration of B2O3 because nanoparticles are expensive. In RSM optimization, the quantity of B2O3 (QoN) and engine load were modeled as variables, and brake thermal efficiency (BTHE), brake-specific fuel consumption (BSFC), nitrogen oxide (NOx), carbon monoxide (CO), hydrocarbon (HC), and carbon dioxide (CO2) were modeled as responses. According to the model, the optimum B2O3 amount was determined as 22 ppm at 1500 W load. Under these conditions, the best results for BTHE, BSFC, NOx, CO, HC, and CO2 are 24.5755 %, 387.533 g/kWh, 523.141 ppm, 0.0413 %, 23.7139 ppm, and 5.2072 % respectively. Moreover, the composite desirability value was within acceptable limits at 0.7156. In addition, the maximum difference between the RSM and the experimental results was 4.81 %, indicating that the RSM gave successful results in this study.Öğe Role of dysprosium substitution on microscopy architecture, structural stability, and crack propagation mechanism in Bi-2212 engineering ceramics(Institute of Physics, 2025-01-28) Kurtul G.; Ulgen A.T.; Armagan O.; Turkoz M.B.; Erdem I.; Yildirim G.This study achieves a strong link between microscopy architecture and fundamental characteristics including electrical conductivity, superconducting, and key mechanical design properties of Bi2.1-xDyxSr2.0Ca1.1Cu2.0Oy (Bi-2212) ceramic structures with different dysprosium molar ratio ranges of 0.00 ≤ x ≤ 0.10. The Dy/Bi substituted Bi-2212 ceramics are characterized by scanning electron microscopy (SEM), electrical resistivity (ρ-T), Electron Dispersive x-ray (EDX) investigations, and microindentation Vickers hardness (Hv) tests. Powder x-ray diffraction (XRD) experimental inspection is also studied to support SEM and Hv results. All experimental findings show significant improvement with an increase in the Dy impurity molar ratio to x = 0.01. On this basis, the Bi2.09Dy0.01Sr2.0Ca1.1Cu2.0Oy ceramic structure exhibits the lowest resistivity of 8.95 mΩ.cm at 300 K and transition width of 4.75 K, and the highest T c o n s e t of 85.00 K and T c o f f s e t of 80.25 K. Additionally, XRD examinations show that optimum Dy ion substitution in the Bi-2212 system stabilizes the high superconducting phase by improving crystallinity, crystallite size, grain orientation distributions, texturing, and interlayer interactions. In contrast, excessive substitution severely deteriorates crystallographic properties. Further, SEM images reveal that the presence of optimum Dy impurity enhances the crystallinity, couplings between the adjacent layers, homogeneous surface appearance, and microstructure. Moreover, the key mechanical design features and stability of the durable tetragonal phase improve significantly for x = 0.01. As a result, the material exhibits superior mechanical properties, including a microhardness of 0.5556 GPa, fracture toughness of 0.5390 MPa.m1/2, elastic modulus of 45.5389 GPa, shear modulus of 18.2156 GPa, yield strength of 0.1852 GPa, and resilience of 0.3766 MPa under a 0.295 N load.Öğe Harnessing nuclear power for sustainable electricity generation and achieving zero emissions(SAGE Publications Inc., 2025-01-23) Khaleel, Mohamed; Yusupov, Ziyodulla; Rekik, Sassi; Kılıç, Heybet; Nassar, Yasser F.; El-Khozondar, Hala J.; Ahmed, Abdussalam AliNuclear power plays a pivotal role in sustainable electricity generation and global net zero emissions, contributing significantly to this secure pathway. Nuclear power capacity is expected to double, escalating from 413 gigawatts (GW) in early 2022 to 812 GW by 2050 within the net zero emissions (NZE) paradigm. The global energy landscape is undergoing significant transformation as nations strive to transition to more sustainable energy systems. Amidst this shift, nuclear power has emerged as a crucial component in the pursuit of a sustainable energy transition. This study examines nuclear power's multifaceted role in shaping sustainable energy transition. It delves into nuclear energy's contributions toward decarbonization efforts, highlighting its capacity to provide low-carbon electricity and its potential role in mitigating climate change. Furthermore, the study explores the challenges and opportunities associated with integrating nuclear power into energy transition strategies, addressing issues such as safety, waste management, and public perception. In conclusion, the global nuclear power capacity is anticipated to reach approximately 530 GW by 2050, representing a substantial shortfall of 35% compared with the trajectory outlined in the NZE pathway. Under the NZE scenario, nuclear power demonstrates exceptional expansion, nearly doubling from 413 GW in early 2022 to 812 GW by 2050. Concurrently, the trajectory highlights a transformative shift in renewable energy investments, with annual expenditures surging from an average of US$325 billion during 2016–2020 to an impressive US$1.3 trillion between 2031 and 2035. These projections underscore the critical role of nuclear and renewable energy investments in achieving global sustainability and emission reduction goals.Öğe Effects of pack boriding temperature on wear and corrosion performance of high-strength armor steel(ICE Publishing, 2025-01-28) Neccaroglu, Vahap; Karademir, Ibrahim; Unal, OkanThis study systematically investigates the effects of pack boriding on the microstructure, hardness, wear, and corrosion resistance of armor steel. A saw-like boride layer was formed as a result of the treatment at temperatures of 800, 900, and 1000 °C. The thickness of the boride layer was positively influenced by increases in temperature. At 1000 °C, the microhardness of the borided surface achieved a maximum level of 3250 HV0.02. The wear resistance of the borided specimens was improved significantly, resulting in a notable reduction in volume losses. Furthermore, the boriding process enhanced the corrosion resistance of the steel by a factor of three to four. Specimens borided at 1000 °C demonstrated the highest level of corrosion resistance.Öğe Cybersecurity Defence Mechanism Against DDoS Attack with Explainability(Mesopotamian Academic Press, 2024-12-26) Mahmood, Alaa Mohammed; Avcı, İsaApplication-layer attacks (Layer 7 attacks), a form of distributed denial-of-service (DDoS) aimed at web servers, have become a significant concern in cybersecurity because of their ability to disrupt services by overwhelming server resources. This study focuses on addressing the challenges of detecting and mitigating the impact of such attacks, which are difficult to counter due to their sophisticated nature. The primary objective of this study is to develop an effective monitoring and defence model to detect, defend, and respond to these attacks efficiently. To achieve this, SHapley Additive exPlanations (SHAP) technology was used to understand the behaviour of the model and to increase the efficiency of the detection classifiers. The defence model is designed with three states: normal, observing, and suspicious. The observing mode, which represents the detection part, is triggered when the server load exceeds a predefined threshold. The detection system incorporates five machine learning (ML) algorithms: decision trees (DTs), support vector machines (SVMs), logistic regression (LR), naive Bayes (NB), and K-nearest neighbours (KNNs). A stacked classifier (SC) was then employed to combine these models to achieve optimal performance. The algorithms were evaluated in terms of accuracy (ACC), precision (PRC), recall (REC), F1 score (F1), and time (T). The SC demonstrates superior accuracy in distinguishing between legitimate traffic and malicious traffic. If the server continues to suffer from overload, the suspicious part of the defence model will be activated, and the mitigation algorithm will be called, which, in turn, bans users responsible for the attack and prevents illegitimate users from connecting to the server. The effects of the mitigation algorithm were noticeable in the server traffic rate, transmission rate, memory utilization, and CPU utilization, confirming its ability to defend against application-layer attacks.Öğe Design and Comparative Analysis of a Microstrip Patch Antenna With Different Feed Technique at 2.4 GHz for Wireless Applications(Institute of Electrical and Electronics Engineers (IEEE), 2024-12-17) Hanashi, Salem Mohamed Al; Almohamad, Tarik Adnan; Aladwani, Azam Isam; Aziz, Ahlem; Guneser, Muhammet Tahir; Albreem, Mahmoud A.Nowadays, according to the wireless application's requirements, which grow very fast, the antenna designs must enhance their output parameters to be compatible with the new generation's demand and to have the advantages of being less weight, low cost and highly reliable. In this paper, we present the design and analysis of a Microstrip Patch Antenna (MPA) with different feeding techniques with the same parameters at 2.4 GHz for the applications of wireless communications, the CST 2020 software was used for antenna simulation, and the comparison was made among Microstrip Patch (MP) Antenna with Inset feed line and else with coaxial feeding. The results show that The MPA fed by a coaxial probe yields superior performance in the standing of return loss, bandwidth, and Voltage Standing Wave Ratio (VSWR) compared to the antenna utilizing an inset feed line.Öğe Internet of Robotic Things (IoRT) approach to lifelong learning and medical education with Internet of Medical Things (IoMT)(CEUR-WS, 2024-01-07) Hasko, Roman; Hasko, Oleksandra; Hakan, KutucuThe article describes the use of relatively new Internet of Robotic Things (IoRT) and Internet of Medical Things (IoMT) paradigms as a logical development of the Internet of Things (IoT) concept in terms of Lifelong Learning and the specifics of medical education from the point of view of the applied use of robotics and artificial intelligence. The Internet of Robotic Things (IoRT) is specifically proposed for robotics and will be important for the development of multi-purpose robotic systems. As the Internet of Things (IoT) provides a reliable framework for connecting things to the Internet and simplifies machine-to-machine communication and data transfer over core network protocols, and is developing at such a rapid pace that billions of devices are now connected, with the prospect of trillions in the coming years, it is understandable to use and the expansion of IoT concepts and technologies to other fields, in particular robotics in its various applications, such as in the military, agriculture, industry, health care, and biotechnology. One of these directions is education, especially lifelong and medical. Another branch of IoT in the medical direction should be highlighted separately, i.e. Medical Education with Internet of Medical Things (IoMT). IoRT is a symbiosis of various technologies such as cloud computing, artificial intelligence (AI), machine learning and the Internet of Things. An example of the implementation of IoRT for education is considered on the basis of the active university Laboratory of Robotics with collaborative robots (cobots) Dobot MG400 and the integration of several such cobots into a single Internet-based system based on ROS and applied applications, which allows teaching new skills and knowledge for the implementation of robotic systems on based on IoT in real-world implementations.Öğe Corrosion behaviour of biodegradable Mg-Zn-Mn-Ce, Mg-Zn-Ca-Ce, and Mg-Zn-Ca-Mn quaternary magnesium alloys in phosphate-buffered saline(Elsevier BV, 2025-01-09) Zengin, Hüseyin; Hofinger, Manuel; Silva Campos, Maria del Rosario; Blawert, Carsten; Polat, Safa; Nienaber, Maria; Bohlen, Jan; Zheludkevich, Mikhail; Hassel, Achim WalterIn this study, lean quaternary magnesium alloys with nominal compositions (wt%) of Mg-1Zn-0.5Mn-0.3Ce (Mg-Zn-Mn-Ce), Mg-1Zn-0.2Ca-0.3Ce (Mg-Zn-Ca-Ce) and Mg-1Zn-0.2Ca-0.5Mn (Mg-Zn-Ca-Mn) were produced using permanent mould direct chill casting and the corrosion behaviours up to 168 h of immersion in phosphate buffer solution (PBS) at 37 °C were investigated. Various techniques were employed to conduct corrosion tests, including weight loss, hydrogen evolution, inductively coupled plasma optical emission spectroscopy (ICP-OES) to quantify the amount of released Mg during both static immersion tests and downstream analysis using a flow cell, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). The obtained data was analysed in detail to compare the corrosion resistance of the three magnesium alloys and the effectiveness of the various test methods. Among the studied alloys, the Mg-Zn-Mn-Ce alloy exhibited the highest dissolution rate during the initial immersion period. However, a substantial improvement in the corrosion resistance was observed for this alloy, especially after 24 h of immersion due to the formation of a dense and compact protective surface film. Additionally, the Mg-Zn-Ca-Mn alloy displayed better corrosion resistance compared to the Mg-Zn-Ca-Ce alloy for immersion durations up to 24 h, above which it significantly decreased.Öğe Co-stand: swashplateless micro aerial robot test stand(Strojarski Facultet, Sveuciliste Josipa Jurja Strossmayera u Osijeki, 2025) Karasahin, Ali Tahir; Gungor, GokhanMicro aerial robots are mainly employed for tasks in indoor environments where high maneuverability is required, particularly in navigating complex and constrained spaces with numerous closely positioned obstacles. Swashplateless mechanisms can reduce noise, increase operational efficiency, and enhance maneuverability, enabling agile and precise movements in indoor operations. This paper introduces a test stand, called Co-Stand, designed to evaluate the performance of the micro aerial robots equipped with the swashplateless mechanisms using ground-based testing, without requiring actual flight tests. The Co-Stand is constructed to collect data on operational performance to investigate the design criteria of the swashplateless mechanisms. The experiments performed on the Co-Stand are used to evaluate both the swashplateless and standard propeller design performances. The results demonstrate that the swashplateless mechanisms achieve the performance criteria of the standard propellers, showcasing their advantages in indoor environments.Öğe An innovative real-time recursive framework for techno-economical self-healing in large power microgrids against cyber–physical attacks using large change sensitivity analysis(Multidisciplinary Digital Publishing Institute (MDPI), 2025-01-04) Jahromi, Mehdi Zareian; Yaghoubi, Elnaz; Yaghoubi, Elaheh; Maghami, Mohammad RezaIn the past, providing an online and real-time response to cyber–physical attacks in large-scale power microgrids was considered a fundamental challenge by operators and managers of power distribution networks. To address this issue, an innovative framework is proposed in this paper, enabling real-time responsiveness to cyberattacks while focusing on the techno-economic energy management of large-scale power microgrids. This framework leverages the large change sensitivity (LCS) method to receive immediate updates to the system’s optimal state under disturbances, eliminating the need for the full recalculation of power flow equations. This significantly reduces computational complexity and enhances real-time adaptability compared to traditional approaches. Additionally, this framework optimizes operational points, including resource generation and network reconfiguration, by simultaneously considering technical, economic, and reliability parameters—a comprehensive integration often overlooked in recent studies. Performance evaluation on large-scale systems, such as IEEE 33-bus, 69-bus, and 118-bus networks, demonstrates that the proposed method achieves optimization in less than 2 s, ensuring superior computational efficiency, scalability, and resilience. The results highlight significant improvements over state-of-the-art methods, establishing the proposed framework as a robust solution for real-time, cost-effective, and resilient energy management in large-scale power microgrids under cyber–physical disturbances.
