انجنيئرنگ اينڊ ٽيڪنالاجيMehran University of Engineering & Technology (Sindhi: انجنيئرڱ ۽ ٽيڪنيڀياس جي جامعہ مهراڻ) (Often referred as Mehran University or MUET) is a public research university located in Jamshoro, Sindh, Pakistan focused on STEM education.Established in July 1976, as a campus of the University of Sindh, and a year later was chartered as an independent university. The academician S.M. Qureshi was appointed as the founding Vice Chancellor of the university. It was ranked sixth in engineering category of Higher Education Institutions in the "5th Ranking of Pakistani Higher Education Institutions" in 2016.
The electrocatalytic valorization of nitrate waste into nitrogenous products - spanning ammonia, urea, and amino acids - represents a transformative approach to sustainable nitrogen management. This review establishes a comprehensive framework for nitrate conversion along three key pathways: (1) selective reduction to ammonia (reaching >95 % Faradaic efficiency), (2) C-N coupling to urea (up to 68 % yield), and (3) direct amino acid synthesis via nitrite (NO2-) and hydroxylamine (NH2OH) intermediates. We systematically analyze shared catalytic challenges, including the competition between N-N vs. C-N bond formation and hydrogen evolution side reactions, while elucidating design principles for tailored catalyst architectures. Single-atom alloys optimize ammonia production at industrial current densities (-500 mA cm(-2)), whereas facet-controlled oxides enable urea synthesis through CO-NH2 coupling. For amino acids, enzyme-inspired motifs stabilize reactive nitrogen species for nucleophilic attack on alpha-ketoacids (68 % alanine selectivity). Reactor innovations emerge as critical enablers: pulsed electrolysis extends catalyst lifetimes 5-fold, while gas-diffusion electrodes overcome mass transport limitations in all three pathways. Techno-economic and life-cycle analyses reveal ammonia production as the immediate economic opportunity ($0.42/kg), with urea and amino acids becoming competitive below $1.50/kg at scale. By unifying fundamental mechanisms, materials design, and process engineering across the nitrate valorization chain, this work provides a roadmap for closing the anthropogenic nitrogen loop - from environmental pollutants to fertilizers and bio-based chemicals.
With the growing global population and the consequent rise in energy and food demands, the search for sustainability has intensified. Solar drying technology emerges as a viable solution for agro-product preservation, offering an eco-friendly alternative to conventional drying methods mainly reliant on fossil fuels. Solar food dryers available in various sizes and designs are tailored to meet diverse agricultural needs. The selection of an appropriate dryer is often influenced by the availability, its types and usage. A comprehensive review of these designs, along with construction details and operational principles of various solar-energy drying systems, is presented. The review hunts recent advancements in the design and optimization of solar dryers for agricultural products, examining direct, indirect, and mixed-mode systems. Key performance parameters such as air flow rate, temperature, moisture content, and drying time are discussed. The review highlights innovations in thermal energy storage, and methods for improving drying uniformity and efficiency. Additionally, economic and environmental benefits are evaluated, highlighting the potential of solar dryers in reducing CO2 emissions and raising food security. Comparative analyses of various dryer configurations and a detailed exploration of future research directions are provided, showcasing the progress and ongoing challenges in this field. The findings show that direct solar dryers, whether active or passive, offer the most cost-effective and practical solution for home use, indirect dryers excel in preserving the quality of delicate products like medicinal herbs, and hybrid systems deliver the efficiency needed for large-scale industrial drying.
Chemical deprotonation behavior of flotation reagents, especially organic chemicals, crucially determines their chemical interactions with mineral surfaces and thereby the selectivity and efficiency of flotation process. This paper systematically investigates the mechanisms of pH-induced deprotonation and complexation of organic reagents in mineral flotation, focusing on tricarboxystarch (TCS) as a model eco-friendly modifier in Cu-Fe flotation systems. In flotation separation, TCS achieved a significant difference of over 75 % in the flotation recovery of pyrite and chalcopyrite from a mixture of these minerals under controlled pulp conditions (pH 6-7). Under controlled pulp conditions, complete deprotonation of TCS was achieved, leading to the formation of large amounts of stable metal hydroxy species on the pyrite surface, but little or no metal hydroxy species on the chalcopyrite surface. Deprotonated TCS (-COO-) was preferentially adsorbed and complexed on the pyrite surface due to the abundance of the highly stable metal hydroxide species Fe(OH)3(s), but its interaction with the chalcopyrite surface was very weak due to the insufficient of metal hydroxide species. FT-IR and zeta potential measurements confirmed the selective adsorption and complexation of TCS onto the pyrite surface over that of chalcopyrite. This basic research improved the selectivity and efficiency of organic flotation reagents through pH-controlled deprotonation and selective complexation, contributing to promoting the sustainability of green flotation technology in mineral separation.
This study introduces an optimal fourth-order iterative method derived by combining two established methods, resulting in enhanced convergence when solving nonlinear equations. Through rigorous convergence analysis using both Taylor expansion and the Banach space framework, the fourth-order optimality condition is verified. We demonstrate the superior efficiency and stability of this new method compared to traditional alternatives. Numerical experiments confirm its effectiveness, showing a reduction in the average number of iterations and computational time. Visual analysis with polynomiographs confirms the method's robustness, focusing on convergence area index, iteration count, computational time, fractal dimension, and Wada measure of basins. These findings underscore the potential of this optimal method for tackling complex nonlinear problems in various scientific and engineering fields. (c) 2025 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY-NC license (http:// creativecommons.org/licenses/by-nc/4.0/).
Conventional desalination methods require significant energy and pose environmental challenges, whereas systems powered by renewable energy face issues related to efficiency and cost-effectiveness. Direct contact membrane distillation in hybrid photovoltaic-thermal systems shows potential, but thorough techno-economic and environmental evaluations are still scarce. A validated numerical model is necessary to accurately represent thermal and electrical behavior across various meteorological conditions. The performance of the system was enhanced through the application of metaheuristic algorithms, specifically Particle Swarm Optimization and Genetic Algorithm, focusing on three critical parameters: outlet fluid temperature, permeate flux, and electrical efficiency. Annual optimization results indicate that May is the peak-performing month, characterized by maximum solar irradiance, which allows a one-panel system to attain a permeate flux of 13.92 kg/m2 & sdot;h and electrical efficiency of 12.7%. The model was expanded to multi-panel configurations (ranging from 2 to 10 panels), with optimal flow rates identified to maintain thermal stability (Tfout <= 343 K). The 10-panel configuration attained a maximum permeate flux of 305.36 kg/m2 & sdot;h and produced 1404.09 m3/year of freshwater. Economic analysis indicated a decrease in the levelized cost of energy from 0.6769 USD/m3 for one panel to 0.2102 USD/m3 for ten panels, alongside a reduction in the payback period from 102 days to 33.3 days. The profitability of the highest configuration over a 25-year project lifespan surpassed $300,000. The environmental assessment indicated a possible carbon offset of 26.57 metric tons of COQ per year, with carbon credit revenue estimated at $13,700 annually based on current emissions trading values. The findings confirm the Photovoltaic-Thermal solar-driven Direct Contact Membrane Distillation desalination system as a scalable and economically feasible desalination option, particularly for off-grid areas with limited water resources. The system integrates renewable electricity generation, low-grade thermal energy recovery, and sustainable freshwater production effectively.
