Journal of Brilliant Engineering (BEN)

Azhar Hussein Razuqi Mustafa Albdairi

Autonomous Vehicles, Aggressive Driving Behavior, Traffic Congestion, Signalized Intersection, Regression Modeling. This study evaluates the impact of varying penetration rates of aggressive autonomous vehicles (AVs) on traffic congestion at a four-legged signalized intersection in Al-Qadisyah, Kirkuk City, Iraq. A simulation using SUMO and regression modeling quantified the relationship between penetration rates and congestion metrics. Introducing 25% aggressive AVs reduced the Mean Max Jam Length by approximately 7% compared to 100% human-driven scenarios, while a full transition to 100% aggressive AVs achieved a 30% reduction. Linear and quadratic regression models were calibrated to represent these relationships, with quadratic models demonstrating superior accuracy based on validation metrics like Coefficient of determination. (R²), Mean Squared Error (MSE), and Mean Absolute Error (MAE). Predictions for intermediate penetration rates aligned with observed trends, offering actionable insights for traffic planning. This research highlights the potential of aggressive AV behavior in reducing congestion, optimizing intersection performance, and informing AV deployment strategies, supported by rigorous calibration and validation of predictive models.

https://doi.org/10.36937/ben.2025.41035

Abdullah Gözüm Taner Tekin Oğuzhan Akgöl

WR-90 (X-band) and WR-62 (Ku-band) are among the most common waveguide sets used in several engineering areas particularly at high frequencies. Conventionally manufactured metallic waveguides are expensive to fabricate due to their need for highly sensitive machining processes. This study presents the development and application of conductive polyurethane-based coating on 3D-printed waveguide structures intended for high-frequency electromagnetic applications. This study presents the development and application of a conductive polyurethane-based coating on 3D-printed rectangular waveguides designed for X-band (8–12 GHz) and Ku-band (12.4–18 GHz) frequencies. Electromagnetic characterization of PLA was conducted to determine its relative permittivity and permeability, enabling accurate simulation of waveguide performance. The designed structures were evaluated using CST Microwave Studio to simulate signal transmission behavior, and the results were compared with Perfect Electric Conductor (PEC) models. The obtained results indicated that the coated waveguides exhibit transmission characteristics highly comparable to metallic ones, with over 99% transmission of electromagnetic waves at the frequencies higher than the cut-off frequencies in both X and Ku bands. The suggested approach offers a low-cost, lightweight, and customizable alternative for microwave and millimeter-wave systems and wherever the waveguides are needed.

https://doi.org/10.36937/ben.2025.41043

Abdüssamed KABAKUŞ Mansur Mustafaoğlu

This research focuses on improving the thermal efficiency of microchannel heat sinks (MCHSs) by integrating porous materials into the channel architecture. Numerical simulations were carried out in COMSOL Multiphysics, utilizing the Brinkman–Forchheimer extended Darcy model to comprehensively represent momentum and heat transfer within the porous structure. Various simulations assessed how different porous layer thicknesses influence critical performance metrics such as the heat transfer coefficient, pressure loss, Nusselt number, and Reynolds number. The incorporation of porous media was found to markedly boost thermal performance by expanding the fluid–solid interface area and promoting enhanced convective heat transfer. When compared with traditional MCHS designs, the porous-enhanced configurations showed a 15–30% improvement in both heat transfer coefficient and Nusselt number, though accompanied by an approximately 20% increase in pressure drop. The optimal performance was achieved with a porous layer thickness of 0.1 mm, as evidenced by the peak Figure of Merit (FOM), reflecting the most favorable trade-off between thermal enhancement and hydraulic resistance. These outcomes highlight the potential of porous-augmented microchannels as a compact and efficient thermal management strategy for electronics subjected to high heat fluxes. The study adds to the current body of knowledge by offering detailed insights into design factors affecting the effectiveness of porous microchannel systems.

https://doi.org/10.36937/ben.2025.41053

Abdulkadir ÖZER Sinem Kayar

Zn1-xCoxO (0 ≤ x ≤ 0.07) samples have been prepared by co-precipitation method. The structural and optical properties of Co-doped samples were characterized using XRD, SEM, EDS, XPS, Raman and UV-Visible spectroscopy. XRD, XPS and Raman spectroscopy results show that the ZnO hexagonal wurtzite structure of all samples is preserved and Co2+ ions are replaced by Zn2+ ions in the ZnO lattice. The average crystallite size of the Zn1-xCoxO nanoparticles were within the range of 25.64–35.86 nm. It was observed that crystal growth increased with increasing Co doping to ZnO. It is seen in SEM images that homogeneously dispersed powders generally have a nanoparticle structure. With the increase of Co concentration, the (Eg) values of Zn1-xCoxO nanoparticles increased from 3.15 to 3.32 eV.

https://doi.org/10.36937/ben.2025.41064

Mehmet Emin ARZUTUĞ

Mass transfer is one of the most important processes in all engineering systems, especially in chemical processes. Mass transfer at the micro- and macroscales, resistances encountered during mass transfer, types of mass transfer, and the measurement of mass transfer rates are key topics. In this context, the methods used to measure the mass transfer coefficient play a key role in measuring mass transfer rates. Since the fluid flow occurs within closed channels and systems, especially in engineering contexts, understanding the mass transfer and determining its rate between a solid surface and a fluid are of primary importance. The most commonly used methods are the Electrochemical Limiting Diffusion Current Technique (ELDCT) and the Napthalene Sublimation Technique (NST). This study reviews the advantages and disadvantages of both methods based on the literature. It is found that ELDCT is suitable for determining convective mass transfer coefficients in liquid fluid flow systems with strongly turbulent conditions. However, NST is more appropriate for gas fluid flow systems.

https://doi.org/10.36937/ben.2025.41070