Browsing by Author "Khan S."

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Laser shock processing of 6061-T6 aluminium alloy: Thermal modelling and analysis
    (Old City Publishing, 2016) Zafar H.; Saklakoglu N.; Irizalp S.G.; Khan S.; Shuja S.Z.; Boran K.; Yilbas B.S.
    Laser shock processing of 6061-T6 aluminium alloy is carried out. Temperature and stress fields are simulated in line with the experimental conditions. Metallurgical changes due to the laser shock and microhardness in the laser treated region are examined using analytical tools that include scanning and transmission electron microscopes and microhardness tester. The depth of shock affected region, plastic strain, and dislocation density are determined numerically and experimentally in the laser treated region. It is found that the temperature attains high values at the centre of the irradiated spot resulting in high rate of evaporation at the surface. The recoil pressure formed, due to high evaporation rate, at the laser treated surface results in plastic deformation of about 500 mm below the surface. A dislocation density of the order 2 × 1013 to 4 × 1013 cm-2 occurs in the surface region. Although high temperature gradients result in high stress levels in the region below the surface vicinity, high recoil pressure results in crack free surface with compressive stress. © 2016 Old City Publishing, Inc.
  • No Thumbnail Available
    Item
    Exfoliated Hydrotalcite-Transition Metal Complex Composite for Eco-Friendly and Efficient Catalytic Degradation of 4-Nitrophenol
    (University of Kerbala, 2025) Khan S.; Memon N.; Memon S.Q.; Yurekli Y.
    Nitrophenols are notorious aquatic organic contaminants found as degradation products of various parent compounds, including pesticides and industrial chemicals that persist in the environment and must be removed. Catalytic degradation is one of the feasible routes to clean the contaminated water systems, however, environmental contamination with catalysts is also widespread. Herein, we report an environmentally friendly catalyst based on composited Fe-Schiff’s base with exfoliated layered double hydroxides (LDH) of aluminum and nickel (hydrotalcite). The composite showed agglomerated pleated LDH structures sheathed with Fe(III)SB. Nitrogen adsorption isotherm data exhibited improved surface area and narrow pores patterns for composite as compared to LDH indicating Fe(III) SB-induced change in the morphology of LDH. Also, significant improvement in catalytic efficiency was observed for Fe(III)SB-LDH over pristine LDH. 4-nitrophenol (10 mg/L) degradation of 99% in five minutes was achieved at pH 6 using a catalyst-to-volume ratio of 1:20 and 20 mM H2O2 as oxidant. It is concluded that phenomenal improvement in catalyst efficiency can be attributed to Fe-Schiff’s base modification. © 2025 University of Kerbala.