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Up to date, the development of highly efficient, visible light-active catalysts remains a formidable challenge due to the enhanced rising of atmospheric CO2 concentration. This study discusses a class of ceria-based high-entropy oxides designed to optimize charge carrier dynamics, surface reactivity, and CO2 activation efficiency. Due to the advantages of high configurational entropy and multi-element synergy, these materials achieved improved photocatalytic performance, surpassing conventional ceria-based systems. Structural and spectroscopic analyses reveal that Pr3+/Pr4+ redox pairs and abundant oxygen vacancies create an electronically disordered yet thermodynamically stable environment, which enhances charge separation and suppresses electron-hole recombination. Photocatalytic experiments demonstrated that Ce0.2Zr0.2La0.2Pr0.2Sm0.2O2-delta (CZLPS) achieves the highest CO2 conversion rate, reaching a conversion of 20.3% under visible light irradiation, significantly surpassing pure ceria (1.4%), with a calculated space-time yield (STY) of 10.15 mol(CO)kg(-1)h(-1) under the same conditions. First-principles density functional theory (DFT) simulations were employed to investigate the CO2 reduction mechanism on CZLPS catalysts. The study elucidates the Gibbs free energy changes (Delta G) for each step of the reaction pathways leading to CO and HCOOH formation, highlighting the Zr site of CZLPS as the most active for the CO2RR, which is responsible for the outstanding catalytic activity
Geopolymers have now made their way through as a low-carbon substitute for Portland cement with the increasing demand for construction materials that are both sustainable and thermally resilient. This research revolves around the fly ash–calcium carbide residue (FA–CCR) geopolymer composites and the attempts that are made to optimize their properties and performance comprehensively, i.e. mechanical, thermal, environmental, and economic ones, by applying an experimental and decision-making integrated framework. In total, ten different geopolymer mixes were formulated through CCR content from 0 to 20
Since the 1970s, accelerated urban development in Doha has contributed to a disjointed and inefficient city structure. While the Doha Metro has begun to address spatial and mobility-related challenges, planners continue to call for a more integrated, strategic approach to ensure safe, accessible, and efficient transit connectivity. In response, the Qatar National Development Framework provides a long-term vision for sustainable urban transformation, with a central aim of embedding the Metro system within the existing urban context and aligning expansion with Transit-Oriented Development (TOD), which promotes dense, multifunctional, pedestrian-oriented neighborhoods along transit corridors. Within this context, this study investigates how TOD strategies can enhance quality of life in mixed-use environments, focusing on the area surrounding Al Mansoura metro station and the adjacent Najma and Al Mansoura districts. Using the Integrated Modification Methodology (IMM), the analysis assesses spatial structure across density, spatial diversity, and connectivity, and derives evidence-based recommendations to improve livability and support sustainable revitalization. To broaden regional applicability, the study also compares Al Mansoura with Olaya in Riyadh-two mid-to-late 20th-century, high-density mixed-use districts undergoing TOD-driven transition-highlighting how spatial form, infrastructure legacy, and urban governance shape TOD outcomes and inform adaptable TOD frameworks for Gulf cities.
In this work, a plasma jetting technique was used to create iron oxide nanoparticles (NPs). The best exposure duration for gas-sensing applications was determined by analyzing the effects of plasma exposure times (8 min, 12 min, 16 min, 20 min, and 24 min) on the structural, optical, and morphological characteristics. Ferric oxide phases, Fe3O4 and Fe2O3, were formed at 33.2° and 35.7° angles, according to X-ray diffraction. As the duration of plasma exposure increased, crystallinity improved. The structure of the nanoparticles changed from clumped aggregates at low exposure intervals (8 min) to regular particles with increasing plasma exposure time, according to scanning electron microscopy. Iron and oxygen were found at 61.42
The introduced investigation demonstrates an extensive finite element analyzation in order to explore thermal transportation features of engine oil enriched with triadic hybrid Nano-size particles exposed to 3D inclined plate incorporated with non-Fourier thermal conduction combine with thermal radiation influence. The mathematical modeling is established by incorporating thermal relaxation impacts to attain definite thermal wave speed, which are pivotal in high temperature and also in nanoscale thermal systems. For the realistic description radiative thermal flux, non-linear thermal radiation is invoked exposed to high temperature gradients. The acquired coupled comprehensive partial differential equations specified by momentum as well as energy transport are modified into a weak variational structure and numerically solution is obtained by utilization of robust finite element approach. The impacts of key physical constraints, including Nano-scale particle volume fraction, radiation as well as also thermal relaxation constraint and inclination angle across temperature compartment and also thermal transportation rate is discussed in detail. Attained outcomes depicts that the inclusion of triadic hybrid Nano size particles considerably intensifies thermal efficiency in contrast to conventional fluids, whilst non-Fourier features moderate thermal propagation closed to the plate surface. The proffered examination highlights the collective role of Nanoscale synergy and also modified thermal conduction theory in enhancing thermal management particularly of lubricated mechanical systems.
