The multi-walled carbon nanotubes (MWCNTs) with controlled diameter distribution are useful in the fabrication of composite materials as reinforcement, due to their superior strength and toughness. Chemical vapor deposition (CVD) is a viable process to synthesize MWCNTs. In this investigation, an attempt has been made to study the effect of CVD process parameters (reaction temperature, flow rate of precursor gas, process time) on the mean diameter of MWCNTs. The MWCNTs of controlled diameter distribution was selectively grown on NiO catalyst supported by Al₂O₃ nano particles. The argon and acetylene were used as carrier and carbon precursor gas, respectively. The catalyst and carbon samples were characterized using field emission scanning electron microscopy, high-resolution transmission electron microscopy, Raman spectroscopy and thermogravimetric/differential thermal analysis. From this investigation, it is understood that the increase in reaction temperature and flow rate of precursor gas increased the mean diameter of MWCNTs but increase in process time decreased the diameter. The diameter distribution and quality of MWCNTs are strongly influenced by the diameter of the catalyst particles.

The purpose of the research is to synthesise a novel series of (E)-2-(4-(1H-indol-3-yl)-6-p-substituted phenylpyrimidin-2-yl)dimethylguanidine derivatives since 3-(1H-indol-3-yl)-1-p-substituted phenylprop-2-en-1-one and evaluate their molecular docking studies, antimicrobial, and anti-diabetic activities. Among all the synthesized compounds (11a-g), compound 11a exhibits excellent CDOCKER energy (−11.36 kcal/mol). The entire compounds (11a-g) confirm very good antimicrobial activity towards the tested microorganisms. In the in vitro anti-diabetic studies, compounds (11a, 11c, and 11g) confirm higher alpha-amylase and alpha-glucosidase inhibition activity. In the in vivo anti-diabetic activities, the synthesized compounds (11a-g) (10 mg/kg, p.o.) investigated by the streptozotocin (60 mg/kg, ip) –nicotinamide (120 mg/kg, p.o.) – induced model in adult male albino Wistar rat and these derivatives show considerable fasting blood glucose level when compared to metformin hydrochloride a potent and well-known anti-diabetic drug as a reference.

Some novel compounds of bis/mono 1-aryl-1H-tetrazole-5-carboxylic acid are synthesized by the hydrolysis of two different synthesized esters, they are ethyl-1-aryl-1H-tetrazole-5-carboxylate and ethyloxo(1-aryl-1H-tetrazol-5-yl)acetate. The ethyl-1-aryl-1H-tetrazole-5-carboxylate is resistant to get hydrolyzed, whereas the ethyloxo(1-aryl-1H-tetrazol-5-yl) acetate undergoes hydrolysis process and converts the ester to title compound. All the synthesized compounds are characterized by IR, ¹H and ¹³C NMR, mass and elemental analysis.The ethyl-1-aryl-1H-tetrazole-5-carboxylateis optimized by DFT B3LYP method and the HOMO and LUMO energy is 5.14 eV and also there is a formation of a weak bond between O₁₈ and C₈ as observed from the AIM analysis result.