RESUMEN
Glass-fiber-reinforced polymer (GFRP) composites are widely used due to their high strength-to-weight ratio and corrosion resistance. However, their properties can degrade under different environmental conditions, affecting long-term reliability. This study examines the effects of temperature and chemical environments on GFRP pipes. Specimens were exposed to salt water and alkaline solutions at 20 °C and 50 °C. Diffusion coefficients and tensile and flexural properties were measured. Advanced techniques (TGA, FT-IR, and XRD) showed a 54.73% crystallinity difference between samples at 20 °C/air and 50 °C/salt water. Elevated temperatures and alkaline conditions accelerated degradation, with diffusion coefficients 68.38% higher at 50 °C/salt water compared to at 20 °C/salt water. Flexural strength decreased by 47.65% and tensile strength by 13.89%, at 50 °C/alkaline compared to 20 °C/air. Temperature was identified as the primary factor affecting mechanical performance, while alkaline environments significantly influenced tensile and flexural modulus. These results underscore the importance of considering environmental factors for the durability of GFRP composites.
RESUMEN
Chemical compounds, such as the CS gas employed in military operations, have a number of characteristics that impact the ecosystem by upsetting its natural balance. In this work, the toxicity limit and microorganism's reaction to the oxidative stress induced by O-chlorobenzylidenemalonitrile, a chemical found in CS gas, were assessed in relation to the green algae Chlorella pyrenoidosa. A number of parameters, including the cell growth curve, the percent inhibition in yield, the dry cell weight, the percentage viability and productivity of algal biomass flocculation activity, and the change in oxygen production, were analyzed in order to comprehend the toxicological mechanisms of O-chlorobenzylidenemalonitrile on algal culture. Using fluorescence and Fourier transform infrared spectroscopy (FTIR), the content of chlorophyll pigments was determined. The values obtained for pH during the adaptation period of the C. pyrenoidosa culture were between 6.0 and 6.8, O2 had values between 6.5 and 7.0 mg/L, and the conductivity was 165-210 µS/cm. For the 20 µg/mL O-chlorobenzylidenemalonitrile concentration, the cell viability percentage was over 97.4%, and for the 150 µg/mL O-chlorobenzylidenemalonitrile concentration was 74%. The ECb50 value for C. pyrenoidosa was determined from the slope of the calibration curve; it was estimated by extrapolation to the value of 298.24 µg/mL. With the help of this study, basic information on the toxicity of O-chlorobenzylidenemalonitrile to aquatic creatures will be available, which will serve as a foundation for evaluating the possible effects on aquatic ecosystems. The management of the decontamination of the impacted areas could take the results into consideration.
RESUMEN
This current study assessed the impacts of morphology adjustment of perovskite BiFeO3 (BFO) on the construction and photocatalytic activity of P-infused g-C3N4/U-BiFeO3 (U-BFO/PCN) heterostructured composite photocatalysts. Favorable formation of U-BFO/PCN composites was attained via urea-aided morphology-controlled hydrothermal synthesis of BFO followed by solvosonication-mediated fusion with already synthesized P-g-C3N4 to form U-BFO/PCN composites. The prepared bare and composite photocatalysts' morphological, textural, structural, optical, and photocatalytic performance were meticulously examined through various analytical characterization techniques and photodegradation of aqueous rhodamine B (RhB). Ellipsoids and flakes morphological structures were obtained for U-BFO and BFO, and their effects on the successful fabrication of the heterojunctions were also established. The U-BFO/PCN composite exhibits 99.2% efficiency within 20 min of visible-light irradiation, surpassing BFO/PCN (88.5%), PCN (66.8%), and U-BFO (26.1%). The pseudo-first-order kinetics of U-BFO/PCN composites is 2.41 × 10-1 min-1, equivalent to 2.2 times, 57 times, and 4.3 times of BFO/PCN (1.08 × 10-1 min-1), U-BFO, (4.20 × 10-3 min-1), and PCN, (5.60 × 10-2 min-1), respectively. The recyclability test demonstrates an outstanding photostability for U-BFO/PCN after four cyclic runs. This improved photocatalytic activity exhibited by the composites can be attributed to enhanced visible-light utilization and additional accessible active sites due to surface and electronic band modification of CN via P-doping and effective charge separation achieved via successful composites formation.