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Process of joining different components by the application of external heat has resulted in induced stress on metals. Friction stir welding has been developed in order to avoid such residual stress development while joining. In this present work, aluminium alloy AA2024 plates were welded by using Friction stir welding process. The experiments were conducted for different combinations of parameters such as rotational speed, transverse speed and axial load. Welded joints developed were tested for mechanical and microstructure analysis. Mechanical joints developed have a maximum hardness of 147.6 hv in nugget zone and maximum tensile strength of 368.76 N/mm 2. Response surface analysis carried out has revealed that transverse speed and rotational speed has high impact on the hardness and tensile strength respectively. The grains at the nugget zone were very fine and uni-axed improving their tensile strength.

Background: Antibiotics play an important role in the treatment of infections to the humans and at the same time, irrational, frequent prescription of higher antibiotics, change in gene composition of microorganisms are all the reasons behind the development and introduction of new antibiotics against different microorganisms. Objective: In this project, an attempt has been made to synthesize some derivatives of diazenyl containing phenyl styryl ketones and also their in vitro screening was conducted against Mycobacterium tuberculosis, Escherichia coli, Klebsiella pneumonia, Bacillus subtilis, Staphylococcus aureus, Aspergillus niger and Candida albicans. Methods: Ten molecules were synthesized which are diazenyl containing chalcones. 4- aminoacetophenone was diazotised and piperidine was coupled with the formed diazonium chloride. Further, the acetoxy group underwent Claisen-Schmidt condensation with differently substituted aldehydes to form the final compounds- the chalcones. The proposed chemical structures were confirmed by different spectroscopic techniques like FTIR, 1H NMR and Mass spectroscopy. TLC was used to know that the reactants were exhausted and the formation of the product occurred. Sharp melting point of the compounds concludes the purity. Results: The MIC of the compounds 3CP, 3DP, 3EP and 3GP is 20 times the MIC of the standard fluconazole drug against Aspergillus niger. The compound 3GP is as equipotent as the standard drug Pyrazinamide with MIC of 3.12 µg/ml against Mycobacterium tuberculosis. Conclusion: The results are quite promising which on further studies may lead to drug molecules against different microorganisms. Especially, 3EP can be considered as a broad spectrum agent due to its potent activity against different microorganisms like Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia and Candida albicans.

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