Journal of Brilliant Engineering (BEN)

Taner Tekin Derya Birhan Hakan Kızıltaş Gökhan Öztürk Tuba Öznülüer Özer Ensar Oğuz

In this study, a core-shell structured Fe3O4@SiO2-Ag nanocomposite structure was synthesized by in situ wet chemistry method with the help of polyvinylpyrrolidone used as stabilizer and auxiliary. SEM-EDS, XRD, and FTIR analyses were performed for the characterization of nanocomposites. Doping Ag nanoparticles on the silica surface prevent agglomeration and small-sized and highly dispersed Ag nanoparticles are obtained. Fe3O4@SiO2-Ag nanocomposite shows superior photocatalytic activity on Brillant Green dyestuff. The Fe3O4@SiO2-Ag nanocomposite showed superior performance in the photocatalytic degradation of Brillant Green, and even after operating 5 times, there was no significant decrease in the activity of the catalyst and it could be easily recycled by creating an external magnetic field.

https://doi.org/10.36937/ben.2024.4905

Beyza Nur Zegerek Bülent Çavuşoğlu

Rain attenuation in 5G satellite communications needs to be considered in planning the communication settings due to the fact that it causes significant attenuation especially above 10 GHz and in low elevation angle Earth-space connection paths. Even though various rain attenuation models have been developed by using measured meteorological data, it is important to know especially which model provides better results for 5G frequencies since direct satellite communication over 5G channels is planned to be used in the near feature. Hence, in this study, prominent rain attenuation models such as the Simple Attenuation Model, Garcia-Lopez model, and ITU-R P.618-14 model were examined. Using these models, rain attenuations occurring at elevation angles of 30°, 60°, and 85° were identified in three different cities in Turkey. Average annual precipitation data from the General Directorate of Meteorology of Turkey for the years 1930-2023 were utilized. The studies on various rain models using different parameters revealed that the attenuation in the 470-780 MHz frequency band is 2.849x10-4 dB, whereas there is a 12.63 dB attenuation in the range of 40.5-43.5 GHz. It was observed that the attenuation increases further with frequencies above 43.5 GHz. Therefore, it is evident that rain attenuation is a crucial parameter in satellite communication systems, particularly in 5G and beyond. This study has revealed that ITU-R P.618-14 model is the best suitable one for high elevation angles and at high frequencies (above 40GHz). As for lower elevation angles Garcia model is more appropriate.

https://doi.org/10.36937/ben.2024.4912

Beyza Sena ÖZLER Beyhan KOCADAĞISTAN Alper Erdem YILMAZ

The rapid increase in the number of microplastics (MPs) in aquatic environments reveals the risk of increasing their harmful effects on living life. MPs, especially those with smaller particle sizes, are very difficult to detect and measure when they reach the aquatic environment. This study investigated the presence of microplastics at the entrance and exit points of the Erzurum Urban Wastewater Treatment Plant. The results showed that the average number of MPs in the influent and effluent was 36400 MP/m3 and 2875 MP/m3, respectively. Primary and secondary treatment processes cannot provide high removal efficiencies in removing MPs from wastewater. However, in WWTPs where tertiary treatment is carried out, as in the WWTP examined, the removal efficiency exceeds 90%.

https://doi.org/10.36937/ben.2024.4914

Shamema Jahan Nirmal Chandra Roy Md. Hafizur Rahman NHM Kamrujjaman Serker

The compressive strength (CS) is a great importance parameter for devising concrete constructions. The concrete frameworks may be exposed to unintentional fire hazards and explosions throughout their worship life. The components of the building include columns, beams and slabs will be exposed to extreme heat in the accidental case of fire hazard. To ensure the execution of concrete construction, it is crucial to comprehend the modifications to the characteristics of concrete under extreme temperature exposure. This study aims to investigate the effects of variation of temperatures, water/cement (w/c) ratios and variation of fly ash on the compressive strength of cement mortar. Fly ash percentages of 0%, 20%, 25%, 30%, 35%, and 40% were taken into consideration. The ratios of cement to water were evaluated as follows: 0.35, 0.40, 0.45, 0.50, and 0.55. The following temperature ranges were taken into consideration: 25 °C, 100 °C, 200 °C, 350 °C, 450 °C, and 600 °C. The test's findings show that, up to 200 °C, the compressive strength of cement mortar with various w/c ratios improves. The strength behavior of concrete increases up to w/c ratio 0.45 and then decreases gradually with the increases in water cement ratios. The strength properties of concrete increase in temperature at up to 200 °C, then decrease gradually with the increases in temperature. Conversely, though above 200˚C, compressive strength decreases gradually with the elevation of temperature.

https://doi.org/10.36937/ben.2024.4918

Hassan Abdullahi Maikano Toyin Yahaya Akanbi

This study explores the effect of steel fiber content on the mechanical properties of Lytag concrete, a lightweight concrete alternative. Splitting tensile tests were conducted on six Lytag concrete mixes containing varying fiber volume percentages (0%, 1%, and 2%). The results demonstrate a significant improvement in splitting tensile strength with increasing fiber content. All fiber-reinforced mixes surpassed the Eurocode 2 (EC2) recommendations for similar strength class lightweight concrete, highlighting the effectiveness of steel fibers in enhancing tensile resistance. Compressive behavior was evaluated using cube specimens. While fiber addition improved post-cracking behavior compared to plain concrete, the elastic modulus of all fiber-reinforced cubes fell short of EC2 recommendations. Additionally, prisms exhibited lower peak loads compared to cubes due to their geometry. The steel fiber content in Lytag beams displayed a positive correlation with both peak load capacity and ductility. However, proper fiber distribution during casting is crucial, as uneven dispersion can negatively impact flexural performance. Incorporating steel fibers offers a valuable approach to improving the tensile and flexural performance of Lytag concrete for applications experiencing these stresses.

https://doi.org/10.36937/ben.2024.4933