https://jams.hsu.ac.ir/ Journal of Applied Material Science en daily 1 Sun, 01 Mar 2026 00:00:00 +0330 Sun, 01 Mar 2026 00:00:00 +0330 https://jams.hsu.ac.ir/article_241110.html https://jams.hsu.ac.ir/article_238016.html In this study, the mechanical characteristics of aluminum 6013-red mud particulate composites were fabricated using the liquid melt metallurgy technique. Test samples were fabricated according to ASTM standards, and their mechanical properties, including ultimate tensile strength (UTS), compressive strength (CS), percentage elongation, and Brinell hardness, were systematically evaluated. The results revealed significant improvements in the mechanical behavior with increasing red mud content. UTS increased from 67.86 MPa for the base alloy to 142.20 MPa at 6 wt.% reinforcement, while compressive strength improved from 148 MPa to 182.42 MPa. The elongation percentage also increased from 44% to 72%, indicating enhanced ductility and strain hardening. Hardness values showed a steady increase from 54.92 BHN to 70.41 BHN with higher reinforcement. The observed enhancements are attributed to the uniform particle distribution, grain refinement, dislocation strengthening, and thermal mismatch effects between the matrix and reinforcement. These discoveries validate that red mud-reinforced aluminum 6013 composites are promising materials for structural applications in automotive, aerospace, and industrial sectors. Furthermore, this study highlights the sustainable use of red mud waste as an economical reinforcement material, contributing to the circular economy and environmental sustainability. https://jams.hsu.ac.ir/article_238210.html This study investigates seawater splitting for hydrogen evolution via a photoelectrode-membrane assembly. A composite photoelectrode of nickel oxide (NiO) and iron-doped graphite carbon nitride (g-C₃N₄) was fabricated and characterized to determine its suitability for photocatalytic activity.  PVA-based membranes were integrated within the reactor to explore ion transport and selectivity in photoelectrochemical device (PEC) configurations. Fluorene–Thiophene–Triphenylamine–Coumarin (FTTC) molecular sensitizer when used in conjunction with a novel Fe/g-C₃N₄/NiO photoelectrode system, resulting in an increase in hydrogen production through solar energy from seawater. The seawater splitting experiments were conducted at various applied voltages, and the system's efficiency was evaluated based on the hydrogen evolution rate, current density, and stability when subjected to seawater. These advancements can be pivotal in decarbonizing maritime energy infrastructures and enabling distributed green hydrogen production in coastal regions. PVA membrane emerges as a promising candidate due to its high selectivity and durability, while the Fe-g-C₃N₄/NiO photoelectrode proves effective for solar-driven hydrogen generation in harsh saline environments. The membrane can reject Cl⁻ ions by more than 90% but it allows H⁺ and OH⁻ ions to pass with a conductivity of 10⁻³ S/cm, and this is the reason why, after 24 hours, only 15% of the photocurrent is lost, while in the case of no membrane, 50% decay occurs. https://jams.hsu.ac.ir/article_239879.html This study focuses on the synthesis of crosslinked films using chitosan and starch, with glutaric acid serving as the crosslinking agent. The concentrations of chitosan and starch varied simultaneously, ranging from 0.1/0.9 to 0.9/0.1, while the crosslinking concentration of glutaric acid was fixed at 1%. The crosslinked films were characterized using Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). These blended films are suitable for controlled drug delivery and mass transport processes, as both polymers are biodegradable. The DSC and TGA thermograms reveal that pure starch and pure chitosan, as well as blended chitosan/starch films, exhibit lower stability compared to the crosslinked blended films, which demonstrate greater stability. Additionally, the analysis indicates that the crosslinked blends are miscible and have intermediate thermal degradation properties. Overall, the results from the DSC and TGA analyses suggest that the crosslinked blended films exhibit improved thermal stability, particularly with higher compositions in ascending order. Thermal analysis provides valuable insights into the stability of these films, making them ideal for applications in controlled drug delivery and the removal of heavy metals. https://jams.hsu.ac.ir/article_240510.html Copper zinc tin sulfide (CZTS) thin films were prepared by the spin coating technique. The Raman spectrum reveals the kesterite crystal structure of CZTS. Scanning Electron Microscopy (SEM) shows agglomerated surface morphology. The EDAX analysis confirms the presence of all the constituent elements of Cu2ZnSnS4. The material with a band gap of 1.92 eV is a promising candidate for the photocatalytic degradation of Methylene Blue (MB)-dye solution, contributing to the eco-friendly wastewater treatment. Photocatalytic activity was studied using a 250 ml MB-dye solution of concentration 10 mg/L. The MB-dye solution containing the CZTS thin-film catalyst placed at the bottom of the beakers was exposed to visible light for irradiation times of 15, 30, 45, 60, 75, 90, 105, and 120 min. The photocatalytic kinetic study showed apparent rate constants of 0.00562 min⁻¹ and 0.00674 min⁻¹ for 2 cm² and 4 cm² catalysts, respectively, and about 46% and 60% degradation were observed after 120 minutes of irradiation. The result confirms that photocatalytic degradation strongly depends on both the thin-film area and the reaction time. https://jams.hsu.ac.ir/article_240548.html Silver-doped titanium dioxide nanoparticles (Ag-TiO₂ NPs) are widely used and increasingly released into aquatic environments, raising concerns about their ecological impacts. This study evaluated the effects of dietary Ag-TiO₂ nanoparticle exposure on the growth performance of Etroplus suratensis fingerlings. Fish were fed diets supplemented with Ag-TiO₂ nanoparticles at concentrations of 1, 10, 100, and 1000 mg kg⁻¹ for 12 weeks under controlled water quality conditions. Acute toxicity (LC₅₀) tests revealed concentration-dependent mortality, with the highest mortality (24% within 96 h) observed at 1000 mg kg⁻¹. Growth performance, assessed through length and weight measurements, exhibited a clear concentration and time-dependent response. The 10 mg kg⁻¹ treatment group showed the highest percentage weight gain (134.24%) and final biomass (34.01 g), indicating an optimal growth response. One-way ANOVA confirmed significant differences among treatments (p < 0.05). Pearson correlation analysis demonstrated a strong positive relationship between weight gain and biomass, while mortality was negatively correlated. Principal component analysis identified weight gain and biomass as major contributors to PC1, whereas mortality dominated PC2. Cluster analysis further highlighted the adverse effects of higher Ag-TiO₂ concentrations. Overall, the findings demonstrate that Ag-TiO₂ nanoparticles exert concentration-dependent effects on Etroplus suratensis, with prolonged exposure to higher concentrations impairing growth and survival, indicating potential ecological risks in nanoparticle-contaminated aquatic ecosystems. https://jams.hsu.ac.ir/article_240552.html Urease, a nickel-dependent enzyme, hydrolyses urea into ammonia and carbon dioxide. The unhydrolyzed urea, in the presence of silver nitrate and tannic acid, forms a yellow-brown complex. This study examines the effect of urea concentration on urease activity using a colorimetric method that involves tannic acid and silver nitrate. The results revealed that low concentrations of urea, less than or equal to 1.00 mM, may limit substrate availability, leading to an underestimation of enzyme activity. An optimal urea concentration of 3.00 mM produced the highest absorbance, 0.949, indicating maximal urease activity (Vmax). The high urea concentrations, greater than or equal to 4.00 mM, resulted in lower absorbance, possibly due to pH shifts or altered reaction kinetics. Low urea concentrations show narrow or sharp SPR peaks at around 414 nM, whereas higher concentrations display broader or wider peaks. The Lineweaver-Burk method shows that the enzyme kinetics of the urea hydrolysis efficiency were greatest at about 3 mM. At this concentration, catalytic efficiency and enzyme/substrate binding were very high (i.e., low Km and near-saturation Vmax). Higher substrate concentrations led to decreased reaction rates. The changing wavelengths suggested substrate inhibition and possible sensor behavior related to nanoparticles. These results indicate that this approach is viable for a very sensitive urea biosensor.