As the demand for energy-efficient homes continues to rise, the importance of advanced mechanical ventilation systems in maintaining indoor air quality (IAQ) has become increasingly evident. However, challenges related to energy balance, IAQ, and occupant thermal comfort persist. This review examines the performance of mechanical ventilation systems in regulating indoor climate, improving air quality, and minimising energy consumption. The findings indicate that demand-controlled ventilation (DCV) can enhance energy efficiency by up to 88% while maintaining CO₂ concentrations below 1000 ppm during 76% of the occupancy period. Heat recovery systems achieve efficiencies of nearly 90%, leading to a reduction in heating energy consumption by approximately 19%. Studies also show that employing mechanical rather than natural ventilation in schools lowers CO₂ levels by 20–30%. Nevertheless, occupant misuse or poorly designed systems can result in CO₂ concentrations exceeding 1600 ppm in residential environments. Hybrid ventilation systems have demonstrated improved thermal comfort, with predicted mean vote (PMV) values ranging from –0.41 to 0.37 when radiant heating is utilized. Despite ongoing technological advancements, issues such as system durability, user acceptance, and adaptability across climate zones remain. Smart, personalized ventilation strategies supported by modern control algorithms and continuous monitoring are essential for the development of resilient and health-promoting buildings. Future research should prioritize the integration of renewable energy sources and adaptive ventilation controls to further optimise system performance.

This paper aims to traitted the combined effects of ferromagnetic particles and magnetic field on mixed convection in the Falkner Skan equation using analytical solution by the Duan–Rach method. Visualization and grouping of effects of various physical parameters such as electrical conductivity of ferro-particles (electrical conductivity calculated using Maxwell model), ferro fluid volume fraction for Magnetite-Fe₃O₄-water and magnetic field represented by the Hartmann number in a set of third- and second-order nonlinear coupled ordinary differential equations. This set of equations is analytically processed using the Duan–Rach Approach (DRA). Obtained DRA results are validated using a numerical solution (Runge–Kutta–Fehlberg-based shooting method). The main objective of this research is to analyze the influence of physical parameters, in particular electrical conductivity, Ferrofluid volume fraction in the case of Magnetite-Fe₃O₄-water, in addition to the types of solid nanoparticles and Hartmann number on dynamic and thermal distributions (velocity/temperature). Results of the comparison between the numerical solution (Runge–Kutta–Fehlberg-based shooting method) and the analytical solution (DRA) show that the DRA data are in good agreement with numerical data and available literature. The study uses Runge–Kutta–Fehlberg-based shooting method) and the analytical solution (DRA) to investigate the effect of mixed convection, in the presence of Ferro particles (Magnetite-Fe₃O₄) in a basic fluid (water for example) and subjected to an external magnetic field on the Falkner–Skan system.

Scour near the banks of a river, particularly at the piers of bridges, is one of the most important components of hydraulic engineering because it plays a significant role in the stability and durability of bridges. This paper performs a complete investigation, utilizing an HEC-RAS-based hydraulic (Hydrologic Engineering Center’s River Analysis System) to evaluate the scour risk in the beds and banks at the Abu Nuwas Bridge piers on the Tigris River in Baghdad, Iraq. Studies that looked at different hydraulic factors, like flow rate, sediment transport, and the shape of the riverbed, were used in the evaluation to guess and model the possible scour depths of existing structures. Calibration (Manning’s n) and model validation were performed with measured discharges of 700 and 425 m3/s, respectively. In the calibration, the n value of 0.03 for the overflow banks and 0.023 for the main channel gives an acceptable performance with R2=0.84, RMS=0.3m, and NSE=0.83. In comparison, the model was valid with R2=0.82, RMS=0.39m, and NSE=0.81. These values are considered acceptable for modelling large rivers like the Tigris River. The research results showed that the risks of scouring under the cladding on the banks, even a small depth of scour, can lead to the collapse of both banks and the stone cladding versus scouring at the bottom of the bed. The study results indicated that the depth of the scour ranged from 0.0 to 2.8 m, with the greatest scour observed at Piers D30 and D148. Further, these results help improve our knowledge of the scour phenomenon and make specific contributions to the design and management of bridges near riverbanks.