Journal of University of Babylon

This review examines the photocatalytic degradation of organic pollutants using nano-‎semiconductor photocatalysts, particularly those derived from onion peel extract, as a sustainable ‎solution for wastewater treatment. It highlights the high catalytic activity, cost-effectiveness, and ‎solar energy utilization of these materials. Recent advancements in magnetic nano-‎semiconductors offer improved separation and reusability, addressing key limitations. Modified ‎photocatalysts such as TiO₂ and ZnO it synthesized via sol-gel, microwave, and ultrasonication, ‎methods, show strong potential for greywater treatment. The integration of photocatalysis with ‎oxidants like Fe³⁺ enhances mineralization efficiency. Operational parameters including pH, ‎pollutant concentration, and catalyst loading are also discussed for process optimization. This ‎review identifies promising directions for scalable and efficient photocatalytic wastewater ‎treatment.‎

Moving bed bioreactor technology is one of the innovative solutions in wastewater ‎treatment, which merges efficiency in biological treatment with design flexibility. This technique ‎is based on the use of tiny plastic carriers (media) that freely move inside the reactor, providing a ‎large surface area for the creation of biofilms containing microorganisms responsible for the ‎breakdown of organic wastes and nutrients like phosphorus and nitrogen. Salient benefits from ‎MBBR technology include handling variable organic loads, less land area compared to ‎conventional systems like activated sludge, and a reduction in energy consumption. It also finds ‎its application in various fields that include domestic and industrial wastewater treatment-related ‎segments, such as food and pharmaceutical industries, and even the reuse of treated water for ‎irrigation or any other industrial purpose. For these objectives to be reached, several technological ‎challenges still have to be addressed, such as the improvement of carriers' distribution inside the ‎reactor, the avoidance of clogging of biofilms, and pollutant removal efficiently under extreme ‎conditions. Recent developments in carrier design, including hybrid or nanomaterials, along with ‎the possible combination of MBBR technology with other advanced technologies, like as UV ‎sterilization or reverse osmosis, have improved performance. The current research tries to give a ‎general review of the MBBR technology and its role in wastewater treatment.‎
Further, it analyzes the scientific research published about MBBR technology by using ‎VOSviewer to: Explore the research trends within the sphere, analyze the scientific citations to ‎identify the most important research sources. Investigate research cooperation at the country and ‎institutional levels and identify the main researchers and influential scientific journals in this ‎specialty. In such a way, the current study is supposed to present the development of scientific ‎research about MBBR technology and may contribute to orienting future studies toward the ‎most important aspects to be improved.‎

I provide a thorough assessment of the pyrolysis technique for making carbon black from ‎waste tires in an environmentally friendly way. It looks at the impact of several major factors—‎including temperature, the layout of the reactor and the environment for the gas—on the carbon ‎black’s yield and quality. Various methods to better carbon black properties are explained, as ‎well as a comparison of old and new pyrolysis practices. Both environmental and industry ‎considerations are highlighted and advice is included on how to maximize operation performance ‎and help fit this approach into circular economy guidelines

Urban intersection is essential to the effectiveness of road networks, particularly in ‎regions that are close to important services like government buildings, schools, and hospitals. A ‎crucial intersection with frequent traffic jams and operational inefficiencies is the Al-Warda ‎signalized intersection, which is situated in the center of Samawah city. The intersection still ‎operates at an inadequate Level of Service (LOS F) even with fixed-time traffic lights, indicating ‎the urgent need for action. This study fills this gap by using a simulation-based methodology to ‎assess and enhance the Al-Warda intersection's performance. Two well-known traffic simulation ‎programs are used in the study: VISSIM, which simulates traffic in great detail at the ‎microscopic level, and Synchro 8, which does deterministic analysis based on the Highway ‎Capacity Manual (HCM). Using video footage taken during peak hours throughout a week, the ‎case study focuses on real-world settings. In order to create precise simulation models, geometric ‎features, traffic volumes, and signal timings were retrieved and processed. After the model was ‎calibrated and validated, a number of augmentation techniques were attempted, such as ‎geometric redesign (lane widening and re-marking) and signal timing optimization. The ‎outcomes demonstrated a notable enhancement in intersection performance. The LOS improved ‎from F to C, and the average delay decreased from 111.1 seconds to 36.7 seconds, ‎demonstrating a significant operational improvement. The results show how well geometric ‎adjustments and simulation-based traffic signal optimization work together to reduce congestion ‎at city intersections. Future studies should investigate AI-driven traffic management techniques ‎and signal control to improve urban mobility even more.‎

The art of maintaining our cultural legacy through architecture is known as restoration. It ‎is the process of restoring historic structures that have lost a large amount of their aesthetic value ‎due to deterioration and cracking caused by time, natural disasters, and other factors.‎
Finding engineering solutions to fix cracks and damage in brick walls is necessary to ‎reduce material loss rather than demolishing buildings or preserving historical or archaeological ‎significance because stone buildings and brick walls sustain significant material damage from ‎weather, time, seismic movements, and other factors.‎
In general, restoration seeks to sustain the buildings through engineering and ‎documentation while maintaining the structural integrity of the structures to be repaired. More ‎than just a building or institution, preserving architectural history and emphasizing its worth has ‎become crucial to urban growth. It maintains the character of the location and the structure and ‎forges enduring ties between succeeding generations. Heritage and historically significant ‎structures that represent the nation's age and civilization are being protected more and more these ‎days.‎
‏ ‏There are numerous engineering and scientific ways to address these damages, enhance ‎the walls, and increase the longevity of brick-built structures and walls.‎

Enhancing efficiency in photovoltaic (PV) power production is a significant engineering ‎challenge, particularly under varying weather and climatic conditions. PV systems offer a green ‎and inexhaustible source of energy; actually, their performance is highly affected by climate ‎variables like as solar sunlight, cell temperature, and partially cloudy conditions. The Maximum ‎Power Point Tracking (MPPT) algorithm commonly utilizes Perturb and Observe (P&O) ‎technique. However, when a large perturbation step is utilized, the algorithm method may ‎oscillate around the peak maximum power point. Conversely, using a small step size enhances ‎tracking accuracy but significantly slows the response time, limiting the system's ability to ‎promptly reach the true MPP under rapidly changing environmental conditions. For solving these ‎issues, a better approach is proposed that uses adaptive step sizes within. This improved ‎algorithm dynamically adjusts the duty cycle of the boost‏ ‏converter's, allowing for more efficient ‎and precise tracking of the MPP with changing climate‏ ‏conditions. A microcontroller is required ‎for the hardware implementation of MPPT. This microcontroller is a component of a robust ‎circuit, namely a solar charge controller. The off-grid PV electricity system is simulation based on ‎MATLAB/Simulink R2024a. The adapted P&O algorithm produces a smoother output and ‎achieves higher efficiency than the traditional fixed-step P&O.‎

This study explores how different values of frequencies of harmonic dynamic load affect ‎the vertical displacement of soils located directly underneath the foundation. A wide range of ‎frequencies (1 – 50 Hz was selected in this study, in addition to four types of sandy soil ‎underneath the foundation: loose, medium, dense and very dense with modulus of elasticity, E ‎of 7000, 19000, 36000 and 70000 kN/m2 respectively. Each type of soil was subjected to three ‎levels of distributed dynamic stresses named 100, 200 and 300 kN/m2. The simulation was ‎carried out theoretically using a two-dimensional software finite element model (FEM) in ‎PLAXIS 2-D package. Two models were used to simulate the soil: elastic and Mohr–Coulomb ‎‎(M-C) models. The results showed that the vertical displacement underneath the foundation ‎decreases with increasing the load frequency for all types of sandy soil investigated in this study ‎and for all values of dynamic load. There is a sharp drop in vertical displacement when the load ‎frequency increased from 1to 10 Hz. The vertical displacement remains constant regardless the ‎value of dynamic load when the load frequency exceeds 30 Hz. Finally, the drop in vertical ‎displacement at first parts of curves (frequency from 1 to 10 Hz.) is sharper in loose sand ‎compared with other types of sandy soil i.e. medium, dense and very dense. ‎

Experimental investigations were conducted to quantify the recoverable thermal energy ‎from the exhaust of a 60 kW internal combustion engine (ICE). The evaluation of the shell-and-‎tube heat exchanger's performance was conducted using water as the working fluid for thermal ‎energy transfer. Utilizing the acquired data, a computational simulation was conducted to ‎optimize both the thermal performance and geometric configuration of the heat exchanger. Two ‎separate heat exchangers were incorporated into the system: one dedicated to the generation of ‎saturated steam and the other designed for the production of superheated vapor. These units ‎were configured in both parallel and series arrangements. In the series configuration, exhaust ‎gases first traversed the superheater followed by the saturation unit. Conversely, in the parallel ‎setup, the exhaust stream was split, with each fraction passing through either the superheated or ‎saturated exchanger simultaneously. In both configurations, the water stream was first ‎introduced to the saturation unit, then routed through the superheater. Significantly, the analysis ‎revealed that under operating pressures below 30 bar, the parallel configuration yielded superior ‎power output, whereas at pressures exceeding 30 bar, the series configuration demonstrated ‎greater performance. The turbine output power was also estimated by incorporating realistic ‎isentropic efficiency assumptions. The findings reveal that harnessing the available waste heat ‎from the diesel engine can yield a minimum additional power output of 18%, underscoring the ‎system’s capability to improve overall energy efficiency in a sustainable and economically viable ‎way.‎

In this study, the effect of the addition of low-density polyethylene (LDPE) at different ‎weight percentages (0, 10, 20, 30, 40, and 50) % The thermal and mechanical features of the ‎high-density polyethylene (HDPE) were examined. The HDPE/LDPE combinations were ‎prepared by using a twin-screw extruder. The mechanical properties (tensile properties, impact ‎strength, hardness) , thermal properties using differential scanning calorimetry (DSC) were ‎investigated‏ ‏‎, the Fourier Transform Infrared Spectroscopy (FTIR) test was also conducted to ‎examine whether a chemical bond was formed in the combination or not And Surface ‎morphological alterations of HDPE, LDPE, and HDPE/LDPE were analyzed using scanning ‎electron microscopy (SEM). The results indicate a reduction in tensile strength and Young's ‎modulus, accompanied by an increase in elongation at rupture. The impact strength was improved ‎by the LDPE addition, while the Shore D hardness decreased. The DSC results indicate that the ‎addition of LDPE reduced both the melting point and the degree of crystallinity. The FTIR ‎indicated that there is a physical interaction between the two polymers. The SEM test revealed ‎that the combination of two phases of LDPE exhibited superior softness compared to the LDPE ‎sample, in addition to the presence of the phases.‎

Extreme weather and climate conditions pose significant challenges to the durability and ‎performance of asphalt pavements, accelerating distresses such as rutting, moisture damage, and ‎cracking. To address these challenges, this study presents the development of a climate-resilient ‎asphalt mixture enhanced with 4% Styrene-Butadiene-Styrene (SBS) polymer, 0.5% Amine-‎Based Anti-Stripping Agent (AD-here® LOF 65-00 EU), and 5% Tall Oil rejuvenator (Delta-S). ‎Laboratory experiments, involving the Hamburg wheel-track test for rutting resistance and the ‎strain-controlled four-point bending beam test for fatigue life (Nf) evaluation and revealed ‎important enhancements over the unmodified control mix. The modified asphalt achieved a 55% ‎decrease in rut depth at 20,000 passes and exhibited a 50% increase in initial stiffness, reaching ‎‎720 MPa at 200 µε and 700 MPa at 400 µε. In terms of fatigue performance, the mix sustained ‎‎120,000 cycles at 200 µε and 65,000 cycles at 400 µε, nearly tripling the durability compared to ‎the control. Moreover, Artificial Neural Network (ANN) models were employed to predict ‎rutting depth and fatigue life up to 100,000 passes and 600 µε, providing a reliable tool for ‎performance forecasting under extreme climatic conditions. The findings reveal that the proposed ‎amendment approach significantly enhances the structural integrity, moisture resistance, and ‎long-term durability of asphalt pavements. This work not only bridges the gap between ‎laboratory testing and practical implementation, but additionally establishes a new benchmark for ‎resilient and sustainable pavement design in challenging environments by promoting longer ‎service life and reducing maintenance needs, leading to minimizing resource consumption.‎

‎ This article presents the design, simulation, and analysis of a high gain, compact size, ‎circularly polarized antenna array operating at 28 GHz frequency in response to the growing ‎needs of 5G networks for small, low profile, high gain, and high-performance antennas. Four ‎identical square patch antennas with two truncated corners make up the antenna array. The patch ‎antennas are powered by a corporate feeding network, which also provides a wide axial ratio ‎bandwidth and enhances the antenna gain. Using Altair FEKO software, antenna simulations ‎revealed an antenna gain of 20.4476 (13.1 dB) and a radiation efficiency of around 99%. The ‎reflection coefficients (S11) were approximately -19 dB throughout a broad bandwidth from ‎‎27.25 GHz to 31.75 GHz. Throughout the 27.7 GHz to 28.3 GHz bandwidth, the antenna axial ‎ratio is less than 3dB. As per the outcomes of the calculations, the suggested antenna is ‎appropriate for millimeter-wave communications, particularly for 5G applications that function at ‎frequencies of 28 GHz.‎

This research aims to enhance the stability of multi-machine power systems by optimizing ‎the design and parameterization of Power System Stabilizers (PSSs). These stabilizers are ‎integrated into the excitation control system to counteract the limitations of Automatic Voltage ‎Regulators (AVRs), which can negatively affect system damping and lead to oscillatory ‎instability.‎
The study begins by highlighting the role of PSSs in damping electromechanical ‎oscillations through the modulation of the excitation signal. The main objective is to ensure that ‎the generated damping torque is in phase with the generator's rotor oscillations, thereby ‎maintaining system frequency within acceptable limits and preventing widespread outages.‎
To achieve these objectives, the research investigates the application of advanced ‎optimization algorithms for the design of PSSs. A comparative analysis is conducted between ‎four optimization techniques: Genetic Algorithm (GA), Particle Swarm Optimization (PSO), ‎Simulated Annealing (SA), and Tabu Search (TS). The strengths and weaknesses of each method ‎are assessed based on their ability to determine optimal parameters that improve system ‎performance.‎
Moreover, the study explores hybridization between global and local search methods to ‎combine the advantages of both approaches. Results show that hybrid algorithms provide ‎superior performance in terms of damping oscillations and enhancing overall system stability.‎
Finally, the research identifies two key challenges: the variability of optimal PSS ‎parameters depending on system operating conditions, and the high computational cost of ‎metaheuristic techniques, which limits their application in real-time scenarios. These findings ‎suggest that adaptive and computationally efficient solutions are necessary for practical ‎implementation in modern power systems.‎