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Go to Editorial ManagerThis research investigates the influence of single and hybrid mineral nanofillers on the morphological, thermal, and electrical properties of epoxy-based glass fiber composites. Nanocomposites were fabricated using hand lay-up technique, incorporating nano-calcium carbonate (CaCO₃) and nano-talc with particle size of 50 to 100 nm into an epoxy matrix with 5-ply E-glass/S-glass fiber. The study evaluates composites with 2-8 wt% of nano-CaCO₃, and hybrid systems containing nano-CaCO₃ (2-8 wt%) and nano-talc (1-4 wt%). Morphological analysis via Scanning Electron Microscopy (SEM) assessed nanofiller dispersion, while thermal properties were analyzed using Differential Scanning Calorimetry (DSC) for glass transition temperature (Tg). Electrical performance was evaluated through dielectric breakdown voltage (ASTM D149) and surface resistivity (ASTM D257). SEM analysis showed filler dispersion depended on concentration, with optimal distribution at 4-6 wt% before significant agglomeration at higher concentrations. DSC results revealed increased Tg with nanofillers, peaking for the composite with 6 wt% CaCO₃ and 3 wt% talc, indicating enhanced thermal stability. The dielectric breakdown voltage peaked at 17.6 kV for 2 wt% CaCO₃ and 1 wt% talc composite, while surface resistivity was highest for 4 wt% CaCO₃ and 2 wt% talc (73.74×1012Ω). All formulations maintained UL 94 V-1 flammability rating. The study concludes that the synergistic interaction between nano-CaCO₃ and nano-talc enables significant tailoring of thermal and electrical properties for advanced applications.
A rapidly expanding global population has heightened the need for engineering technologies aimed to enhancing the mechanical properties of weak soil, raising concerns about the sustainability of engineering practices that depend on energy-intensive materials and methods from earlier times. Traditional ground improvement techniques like compaction, preloading, vibration, and chemical grouting are typically costly and frequently have very high energy and CO2 footprints. Soil stabilization employing bio-enzymes has been viewed as a resilient and ecologically beneficial method for modifying the soil characteristics. Calcite-induced precipitation methods have recently become potential techniques in geotechnical engineering for improving the shear strength of soils. One of the most promising methods among them is enzyme-induced calcite precipitation (EICP). Enzyme induced calcite precipitation (EICP) is a bio-inspired technique based on the precipitation of calcium carbonate for enhancing the geo-mechanical properties of soils. In this technique, calcium carbonate acts as a cementitious agent that binds the soil particles together at the points of contact hence, increasing the strength and stiffness of treated soils, while relatively reducing the soil permeability and porosity. The achieved enhancements make EICP useful for applications such as ground improvement, construction materials, and erosion control over traditional binders. It is an environmental friendly technique that has generated great interest to geotechnical engineers. EICP particularly, has proven to be more effective since its application to all soils coarse and fine which have small pore size. This review thoroughly assesses the use of the EICP approach as a soil stabilization strategy conducted by various researchers. This review article studies urease and its implication on the characteristics of treated soil such as shear strength, permeability and micro-structural changes.
Accurately identifying the kind and amount of dissolved metal salts in wastewater used in oil refining processes is an iconic feature of ultraviolet and visible absorption spectroscopy. This method relies on the dissolved metal salts' ability to absorb light at certain wavelengths after reacting with it. The experiments were conducted in a lab setting with a broadband source (200-800 nm) to measure the absorbance of dissolved element salts and precisely identify the lowest concentration up to 2 ppm. A mixture of the mineral salts from oil refining operations was prepared and diluted to different concentrations using a standard solution. This allowed us to study and compare this result with the absorbance behavior of the wastewater from the Al-Dora Refinery. The two results reinforced that we can accurately estimate the detection parameters for the lowest water contamination. These materials are lead nitrate (PbNO3), phenol, calcium carbonate (CaCO3), sodium chloride (NaCl2), sulfide (SO4), and nitrate (NO3). At wavelengths of 340, 404, and 741 nm, the concentrations (10, 20, 30, 40, 50, 60, 70, 80, 90, and 100) ppm were found, and for the concentration of 10ppm, the absorbance (0.15323, 0.15326, and 0.14685) was found, respectively. The process that has been tested with varying concentrations is considered and simulates the variation in river water concentrations caused by the river's water level and flow rate changes by the effect of rain abundance and thawing. It is fast, accurate data analysis, and a lower cost compared with the other chemical analysis and conventional methods.