Molybdenum disulfide (MoS₂) is a two-dimensional material with electronic and thermal properties that make it promising for thermoelectric applications. This research presents the results of synthesizing and characterizing MoS₂ thin films obtained by Physical Vapor Deposition (PVD) on silicon dioxide (SiO₂) substrates. Three experimental approaches were explored to assess how changes in deposition conditions affect the material quality. In the first trial, films were formed from commercial MoS? powder in a sulfur-rich (S₂) atmosphere using a PVD tubular furnace. Next, water vapor (H₂O) was added to the process to observe possible improvements in material formation. Finally, silver doping was investigated, introduced during deposition to examine structural and vibrational changes in the MoS₂. The samples were characterized by Optical Microscopy (OM) and Scanning Electron Microscopy (SEM), as well as Energy Dispersive Spectroscopy (EDS), used to evaluate surface morphology and composition. X-ray Diffraction (XRD) was employed to identify the crystalline structure, while Raman Spectroscopy revealed the E₂g¹ and A₁g vibrational modes, associated with the crystallinity of the material. The results indicated that the presence of H2O during deposition favored the growth of more ordered films, with more intense peaks in XRD and Raman spectra. On the other hand, silver doping caused vibrational changes that suggest modifications in the electronic structure of MoS₂.  These findings reinforce the material’s potential for use in thermoelectric devices and demonstrate that variations in synthesis conditions can significantly enhance its structural and functional properties.

Masonry infill walls are commonly used in reinforced concrete (RC) frame buildings for both architectural and environmental reasons.  Although many consider RC systems to be non-structural, their interaction with surrounding frames can have a significant impact on their lateral stiffness, strength, and seismic performance. This can lead to stiffness issues and soft-story failures during earthquakes. This study looks at the structural function of masonry infills. It compares the experimental load-displacement backbone curve of an infilled RC frame with numerical predictions from four well-known Equivalent Diagonal Strut (EDS) models: Holmes, Mainstone, Liau and Kwan, and Paulay and Priestley. We looked at how well the models performed for both serviceability (initial stiffness) and ultimate limit states (peak lateral strength). The findings demonstrate a definite trade-off in predictive accuracy. With a mean stiffness ratio of 1.38, the Mainstone model yielded the most accurate estimate of elastic stiffness. The Holmes and Liau and Kwan models, on the other hand, significantly overestimated stiffness (ratio = 1.92). All models were conservative (ratios < 1.0) for peak strength. Holmes and Liau and Kwan produced the closest predictions (ratio = 0.84), while Mainstone was the most conservative (ratio = 0.80). These results indicate that the best choice of EDS model depends on the design goal: Mainstone is better for serviceability assessments, while Holmes and Liau and Kwan provide more realistic predictions for ultimate lateral capacity.

The role of borax as a setting-time modifier in Class F fly ash-based geopolymer concrete is not yet well understood. Particularly with respect to its effects on mechanical and fresh properties. This research investigates the influence of borax incorporation on the properties of geopolymer concrete. Class F fly ash from the Tanjung Jati B power plant was used. Borax was added at fly ash weights of about 0%, 5%, 10%, and 15%. Tests were arranged to observe setting time, compressive strength, elastic modulus, and slump value to assess mechanical performance and workability. The results represent, borax effectively prolongs the initial and final setting times, with greater effectiveness in Class F fly ash (low CaO) than in Class C fly ash (high CaO). The addition of 5% borax resulted in a higher compressive strength and modulus of elasticity. However, higher borax dosages reduced mechanical properties by inhibiting geopolymerization. An increase in borax content reduced slump values, reflecting lower workability due to higher mixture viscosity. While borax can effectively regulate setting time in Class F fly ash–based geopolymer concrete, its dosage must be carefully optimized to prevent negative effects on strength and fresh concrete performance.

The increasing presence of recalcitrant organic pollutants in water bodies has driven the development of advanced treatment technologies capable of promoting effective degradation beyond conventional processes. In this study, a graphene oxide (GO)–titanium dioxide (TiO2) composite was synthesized via a chemical route and evaluated for photocatalytic degradation of methylene blue under UVC irradiation. Graphene oxide was produced by electrochemical exfoliation of graphite, followed by incorporation into TiO2 at 5 wt.% to form the TiO2:GO5 composite. Structural and morphological characterizations by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and FTIR confirmed the formation of anatase-phase TiO2 and successful integration of GO without secondary phase formation. Photocatalytic performance was assessed by monitoring dye concentration decay over 5 h of irradiation. The TiO2:GO5 composite achieved more than 70% methylene blue removal, reaching a final C/C0 value of 0.28, compared to 0.29 for pure TiO? under identical conditions. The degradation followed pseudo-first-order kinetics, with apparent rate constants of 2.302 × 10-¹ h-¹ for the composite and 2.241 × 10-¹ h-¹ for pure TiO2, corresponding to a 2.7% increase in reaction rate. Enhanced initial adsorption and slightly faster absorbance decay were observed for the composite throughout the irradiation period. Although the performance enhancement is moderate, the incorporation of graphene oxide improved charge separation and adsorption behavior without requiring high-temperature calcination. These findings demonstrate that GO modification represents a viable strategy to enhance TiO2 photocatalytic activity under energy-efficient synthesis conditions, highlighting its potential application in advanced water and wastewater treatment systems.

Carbon quantum dots (CQDs) have emerged as promising spectral modifiers for photovoltaic devices due to their photoluminescent down-conversion properties. In parallel, silica-rich industrial residues represent an environmental liability but also a potential source of functional materials. This study investigated the valorization of SiO2-rich mining residue for the production of a sodium silicate matrix incorporating CQDs as a spectral conversion overlayer for solar panels. The treated residue successfully yielded sodium silicate, and CQDs were synthesized and integrated into the matrix. Photovoltaic testing demonstrated that panels coated with industrial-derived sodium silicate exhibited an initial efficiency increase of 8.91% compared to standard panels. However, coatings containing CQDs with the residue-derived sodium silicate showed reduced performance in early-stage testing, and all samples exhibited progressive opacity after six months, indicating limited long-term stability. These findings highlight both the potential and the challenges of integrating CQD-based spectral management with mining residue valorization. While the approach demonstrates feasibility in short-term performance enhancement, material stability remains a critical barrier for practical implementation.