What proportion of banana that produce an effevtive sunscreen?5 answersThe research studies on banana peels indicate that they contain bioactive compounds like phenolics, flavonoids, tannins, and carotenoids, which contribute to their sunscreen effectiveness. Different extraction methods have been explored, such as using methanol, ethanol, and acetone, with ethanol extracts showing the highest antioxidant activity at 75.71%. Additionally, incorporating titanium dioxide into sunscreen formulations based on papaya fruit extracts has shown to increase SPF values by up to 61%. Pineapple rind extracts have also been studied for sunscreen formulations, with SPF values ranging from 2.66 to 2.83, demonstrating their potential as sun protectors. Furthermore, a combination of mountain papaya fruit and mangosteen peel extracts in skin lotions has shown promising SPF values of 21.70 to 28.64, indicating their effectiveness as sun protectors.
Amount of percentage for replacement of sand and cement in concrete4 answersThe research studies provide insights into the replacement percentages for sand and cement in concrete. For sand replacement, studies suggest that 30 to 40% of natural sand can be effectively replaced with crushed stone waste. Additionally, replacing 25% of natural fine aggregate with used foundry sand is found to be successful, with a decrease in compressive strength beyond this percentage. Furthermore, replacing 50% of river sand with M-sand in concrete mixtures has shown excellent strength parameters and economic benefits. When it comes to cement replacement, one study recommends not exceeding 25% replacement with fly ash to achieve desired strength levels. Another study indicates that sawdust can replace up to 20% of sand in concrete, with a recommended water-cement ratio not exceeding 0.5 for optimal properties.
Does the addition of banana fibers as additives significantly improve the water resistance of concrete?5 answersThe addition of banana fibers as additives in concrete has shown significant improvements in water resistance. Research indicates that incorporating banana fibers in high-strength concrete (HSC) enhances durability properties, such as long-term compressive performance, rapid chloride penetration, sorptivity, and water absorption. Additionally, the inclusion of banana fibers in high-performance fiber reinforced concrete composites blended with agricultural wastes like bagasse ash and rice husk ash led to substantial improvements in the mechanical properties of the concrete. Furthermore, the use of banana stem fibers in ferrocement lightweight fiber concrete resulted in increased compressive and tensile strengths, demonstrating enhanced water resistance and durability of the material. These findings collectively suggest that incorporating banana fibers in concrete formulations can indeed significantly improve water resistance properties.
Why is the hydration rate of cement not constant?4 answersThe hydration rate of cement is not constant due to various factors such as the influence of curing temperatureand the presence of supplementary cementitious materials like palm oil fuel ash (POFA). Additionally, the anisotropic growth of calcium-silicate-hydrate (C-S-H) in cement hydration plays a role, as classical models fail to explain the kinetics due to the nonlinear evolution of C-S-H supersaturation. Models like the Affinity Hydration model have been developed to simulate the hydration process, showing that hydration behavior is complex and influenced by environmental conditions. Furthermore, new models have been proposed to predict hydration over extended periods, considering factors like pore relative humidity and temperature variations, crucial for structures with design lifetimes exceeding a hundred years.
What are the skin benefits from banana peels?3 answersBanana peels have several skin benefits. They are rich in natural antioxidants, which can have a moisturizing and anti-oxidizing effect on the skin. The peel also contains phenolic compounds and enzymes that can be used as a health supplement due to their richness in natural antioxidants. Additionally, banana peels have been documented as an antimicrobial agent, which can help protect the skin from harmful bacteria. The texture of banana peel is similar to human skin, making it a suitable alternative for practicing suturing skills in medical training. Furthermore, banana peels have bioactive chemical components that can be used for pharmaceutical purposes in treating various skin diseases. Overall, banana peels offer a natural and eco-friendly option for skincare and can be utilized in various applications such as textile clothing and masks.
How does banana peel powder contribute in concrete strength?4 answersBanana peel powder contributes to the strength of concrete by increasing the flexural strength and reducing the exothermal reaction. The use of banana peel powder as an admixture in concrete has been found to increase the flexural strength, although the increase in compressive strength is relatively lesser. Additionally, the exothermal reaction in concrete, which can lead to temperature emission, is reduced when dried banana peel powder is used as an admixture. The specific engineering properties of banana skin ash (BSA) have also been studied, and it has been found that concrete containing BSA exhibits improved compressive strength and microstructures. The optimal percentage of BSA as a supplementary cement material in concrete has been determined to be 1.25%. Banana fibers have also been used to reinforce concrete and decrease the rate of crack propagation, with the proportion of fibers optimized to maximize compressive strength.