rafiq ahmed

Coastal area construction provides the biggest challenges in the country's development. Mechanical strength and durability are the two main challenges in coastal areas when compared to conventional construction. The proposed study explores the effect of recycled melamine powder and  poly (vinyl-co-ethylene) copolymer on workability, setting time, aggregate-to-cement adhesion, and the effect of moisture and saline water on concrete mechanical properties. Portland cement was sieved and dried sand, and aggregate was mixed in the ratio of 1:2:4 (cement: sand: aggregate) by weight. The three constituents were manually mixed with 40-45 wt. % tap water, based on cement content, until a homogenous mixture was visibly observed. Cylindrical samples with continuous tampering to avoid voids were cast in standard molds of 4”x 8” (100 x 200 mm) dimensions. The molds were covered and left for 24 hours for setting. Unmolded concrete samples were cured for 7 and 28 days in tap water. The concrete samples were dried and stored for further testing. The same concrete samples were prepared with an additional 1 wt. % and 3 wt. %, based on the cement content, of melamine and poly(vinyl-co-ethylene) copolymer. The samples were subjected to water slump height, water permeability, compressive strength and flexural tests, and carbonation tests. The results showed a 10 % and 16 % decrease in slump height for 1 % and 3 % loadings, respectively for both polymers when compared to controlled samples. Reinforced concrete showed less water penetration for both polymers due to their hydrophobic nature. Higher compressive and flexural strengths and low carbonation depth were obtained for reinforced concrete irrespective of the polymers used in this research.

In this research, Poly-Naphthalene Sulphonate (PNS) properties and working in concrete are enhanced to get the required workability and high strength of 10000psi. PNS usually does not work in high-strength concrete due to the presence of more cement content in its mix design. PNS dispersing effect in cement particles decreases as the cement content is increased. Therefore, its dispersion property and zeta potential are enhanced to make it compatible with high-strength concrete. Before modification, PNS is optimized in a mixed design of 10000psi concrete. When targeting dispersion, firstly PNS is modified by removing its oligomers which were creating a hindrance for cement particles. The required strength cannot be achieved while the required slump is achieved. In the other trial, sodium sulfate was added to concrete to increase dispersion by increasing sulfate ions in it, this sample did not work due to the presence of silica fume in the mix design. Similarly, many additives are added to increase dispersion like sulphonic acid with the defoaming agent, and by increasing gluconate dosage in the admixture solution. From the gluconate increment, get nearer to the required strength, which was not the exact required one. In the second phase, the hydration of cement is targeted by adding sodium lauryl ether sulfate to increase the viscosity of mixing water by which the active point of cement will increase but it gave the strength failure. Similarly, polytetrafluoroethylene was added which gave a better result but not the required strength. This additive is also tried with a gluconate-incremented sample to target both factors simultaneously. But the strength cannot be achieved and in the last by adding sulfuric acid to the mixing water rate of hydration of cement is slowed down by the water absorption principle and the required strength. The workability was achieved at a very cheap cost.

In the present study, attempts are made to enhance the corrosion resistance in underground storage tanks. For this purpose glass fiber reinforced unsaturated polyester was used to coat the underground storage tank. The coating was applied by the hand layup technique. Multiple layers of glass fiber reinforced coating were applied, with the matrix composition of 97% polyester, 2% hardener, and 1% cobalt as an accelerator. Better corrosion resistance was observed when tested for the corrosion activity of the reinforcing steel with applied coating. It also provides better mechanical properties. For impact energy, the Izod test was performed. The mechanical properties and corrosion resistance were increased as increasing the fiber layers in the composite. This research is very helpful for future use as it provides a more cost-effective and better mechanical properties solution for the coating of the underground storage tank.

A cotton-based hydrogel nanocomposite was effectively arranged through free radical graft co-polymerization of a combination of Acrylic Acid (AA), acrylonitrile (AN), and sodium acrylate (NaA) onto the texture pursued by the addition of Ag nanoparticles. Ammonium persulfate (APS) and potassium persulfate (KPS) were utilized as initiators within sight of a crosslinker methylene bisacrylamide (MBA). These samples are characterized by Fourier Transform IinfraRed (FT-IR), and X-Ray Diffraction (XRD) to affirm the hydrogel nanocomposite structure. At first, the influencing factors onto graft polymerization were efficiently enhanced to accomplish a hydrogel with a swelling limit as high as expected under the circumstances. The came about nanocomposite shows overly hydrophilic and superhydrophobic properties. In this manner, the grafted texture, specifically from oil/water, blends separated water with high separation productivity. The impacts of channel type, level of covered hydrogel on cotton, nearness of Ag nanoparticles, extricated oil type, and temperature effect were studied on the hydrogel. Nanocomposite on the partition effectiveness of channels was additionally examined. The as-prepared materials were super hydrophilic and superoleophobic in air and submerged in water. Diesel oil and vegetable oil were used selectively at 10% and 20% volume in water. The separation efficiencies for each were observed on different samples, with and without Ag nanoparticles. The materials can isolate the scope of various oil/water blends (counting immiscible oil/water blends and surfactant-balanced out emulsions) with >97% separation efficiency. Effect of poly AN-CO-NaA and poly AN-co-AA ratios the samples show the same nature, their weight increases with time. The rates were different owing to the monomer ratios. Hence the more hydrophilic groups present, the greater the absorption rate, which shows the characteristics of this poly AN-co-AA grafted hydrogel. Sodium acrylate at different proportions in poly AN-co-NaA was tested, and it can be deduced that hydrophilicity increased with greater proportions of the sodium acrylate. Along these lines, the straightforward and effortless technique has superb potential in various applications such as industrial oil-polluted wastewater and oil spillage clean-up.

Excessive use of petroleum-based lubricants and their hazardous disposal has increased environmental pollution; hence the need for eco-friendly lubricants has been increased to meet the requirements of industry and automotive. Due to the oil crisis, the world’s attention has been diverted to producing bio-lubricants from non-edible sources. The use of non-edible sources can overcome the problems of toxicity, hazardous nature, and non-biodegradability. This study discusses the effect of various parameters on transesterification reaction to produce bio lubricant from Neem oil. The dried neem seeds were crushed, and the oil was extracted using the Soxhlet extraction method using n-hexane. The bio lube was produced by a double transesterification process using CaO as a catalyst. The effect of temperature, the molar ratio of ethylene glycol to oil, and catalyst wt% on yield bio lubricant was observed. The temperature varied from 110 to 140 °C, molar ratios of ethylene glycol to oil varied from 2:1 to 8:1, and the catalyst wt% was 0.8 to 1.6%, keeping the reaction time and other conditions constant. During the experimentation, it was observed that the yield was low at 110°C, but as the temperature increased, yield also increased, but no significant change in yield was observed beyond 130°C. The maximum yield observed at 130°C, and 140°C was 93.7% and 94.37%, respectively. Similarly, as the molar ratio increases, the yield of bio lube also increases, and the maximum conversion was 94.3% achieved at ethylene glycol to oil molar ratio of 8:1, but a molar ratio 6:1 may be considered optimum because there is no substantial increase in conversion after 8:1. Moreover, the profile was observed by varying the amount of catalyst and it is evident from the results, as the amount of catalyst increases as the conversion increases from 66% to 95%; however, at a catalyst ratio of 1.6 wt %, a yield was decreased slightly to 94.2. It has been observed that the temperature significantly impacts the production yield of Biolube.