NEVU Journal of Engineering and Architecture

Investigation of the Properties of WC Layer Coated on the New Generation Nodular Graphite Cast Iron Surface with Thermoreactive Diffusion Technique

Erçin YAKUT — 2024-07-23

In this study, WC coatability was investigated on the surface of new generation spheroidal graphite cast iron, which has a high silicon content and is preferred due to its properties, using the Thermo Reactive Diffusion (TRD) method. For this purpose, a mixture of 45% Al₂O₃+45% FeW and 10% NH₄Cl was used as coating powder, and the GGG70 spheroidal graphite cast iron surface, which was the substrate material, was coated with the TRD method at 1000 °C for 4 hours and at 1100 °C for 2, 4 and 6 hours. . The successfully obtained coated samples were sectioned and their coating morphologies, thicknesses and microhardness were examined. The phase structures formed on the coating surface were obtained by the X-Ray Diffraction method (XRD). As a result of the study, the lowest coating thickness was obtained on the sample coated at 1000 °C for 4 hours. Although the highest coating thickness was obtained on the sample coated at 1100 °C for 6 hours, flaking began to occur in the coatings. As a result of the microhardness analysis, it was observed that the hardness of the coating layer was approximately 8 times higher than the substrate material.

Analyzing Photovoltaic System Performance through Two Phase Interleaved Boost Converter and Particle Swarm Optimization-Based Maximum Power Point Tracking

Furkan Dursun — 2024-07-23

Photovoltaic (PV) systems, which convert solar energy into electricity through irradiation, play a crucial role in renewable energy generation. To ensure these systems operate efficiently and maximize power output, Maximum Power Point Tracking (MPPT) is essential. Numerous algorithms have been developed to optimize MPPT, one of which is the metaheuristic Particle Swarm Optimization (PSO) inspired by swarm intelligence. Boost converters are used to increase and regulate the voltage and current output of PV panels, ensuring they operate at the MPP under varying irradiation and temperature conditions. The synergy between boost converters and PSO-based MPPT has been examined, revealing significant potential in enhancing energy harvesting efficiency. Simulations and experimental validations demonstrate that the proposed integration outperforms traditional MPPT techniques. This article presents a comprehensive study on the implementation of a boost converter and the use of the PSO algorithm for MPPT in PV systems. The research contributes to the sustainable use of solar energy resources by enhancing the reliability and efficiency of PV systems. The findings offer substantial insights into the intricate design and optimization processes of photovoltaic installations. These insights are pivotal in advancing the efficiency and reliability of PV systems, which in turn, facilitate the broader adoption of renewable energy technologies. By addressing critical aspects of PV system performance and improving energy harvesting capabilities, this research accelerates the adoption of renewable energy, supports global sustainability efforts, and promotes a cleaner, greener energy landscape.

Towards a study of the operation of a Hydrogen-‎based ‎Proton Exchange Membrane Fuel Cell for ‎Power ‎Generation

Salma El Aimani — 2024-07-23

Energy challenges continue to grow due to the depletion of usual energy sources on the one hand, and climate change due to pollution on the other. The development of new energy production systems is therefore a priority for the scientific community. Hydrogen is a solution for the future that preserves the environment and makes it possible to obtain electricity through chemical reactions. Hydrogen technologies and in particular proton exchange membrane fuel cells (PEMFC) have many advantages to be the clean source of electrical energy of tomorrow. In addition, the fuel cell can operate with pure hydrogen, which can be produced not only from fossil fuels such as natural gas and oil, but also from renewable energies (wind, solar, ‎hydraulic, biomass).‎ Fuel cells (PEMFC) seem to be a promising alternative. One of the most important scientific and technical challenges for the design and production of a fuel cell is to know how a fuel cell behaves in its real environment of use. The purpose of this paper is precisely to analyze the performance of the PEMFC type fuel cell using a modeling and a numerical simulation carried out under the Matlab / Simulink software. In the light of this study, it would be possible to assess the behavior of the PEFMC and compare it to the actual data..

Hibrit Sistemler ile Mikro Şebeke Tasarımı: Nevşehir Hacı Bektaş Veli Üniversitesi Örneği

Elif Tuba Öztürk — 2024-07-23

While the need for energy is increasing day by day with the increase in world population, rapid urbanization and technological developments, the use of fossil fuel resources to meet this need is quite common. However, the use of fossil fuel resources brings with it many disadvantages. While air pollution occurs due to harmful gases released into the atmosphere, climate changes occur with global warming. In addition to the damage to the environment, the tendency towards alternative energy sources has been increasing recently due to the limited nature of these resources. In our country, clean energy can be obtained by using renewable energy resources. Continuity in energy production can be achieved with hybrid systems where resources such as sun and wind are used together. Necessary investigations have been carried out for Nevşehir province, which has high solar and wind energy potential. With this study, hybrid systems containing grid-connected solar, wind and hydrogen energy were designed to meet the electricity needs of Nevşehir Hacı Bektaş Veli University. While the excess energy produced in the designed systems is transferred to the grid, the energy needs of the university are met and additional income is provided. Based on the analyses, the most suitable system was determined.

Channel Estimation of Correlated Channels in RIS-Assisted Wireless Communication Systems

Yasin Kabalci — 2024-07-23

In Reconfigurable Intelligent Surfaces (RIS) aided communication systems, knowledge of the channel state information is critical in optimizing the reflection coefficients of the RIS. However, the existing methods proposed for the non-parametric channel models involve a large training overhead. To reduce the channel estimation overhead, the spatial correlation inherent in the communication systems due to small inter-element distances in the antennas and the RIS as well as the directionality of the antennas can be exploited to group a set of adjacent RIS elements to share a common training reflection coefficient, thus effectively reducing the number of training time slots needed for the channel estimation by a factor of group size. The study defines a correlated channel model for Uniform Linear Array (ULA) and Uniform Planar Array (UPA) antenna arrays and implements a channel estimation algorithm based on the Discrete Fourier Transform (DFT) reflection training pattern at the RIS. The effects of the correlation coefficients and the RIS size on the channel estimation performance are observed. The results show that even at low correlation, the grouping scheme is effective at reducing the training time.