One of the ways of reducing metal corrosion and its devastating effects is by using organic corrosion inhibitors. This is because of the π-conjugation in their moieties, their ability to donate electrons to the metal’s vacant d-orbitals, and their low lying LUMO orbitals for accepting electrons as well from the metal, all these improve their adsorption on the metal surface. (E)-5-((4-benzoylphenyl)diazenyl)-2-hydroxybenzoic acid (AD4) was synthesized via the coupling reaction of p-aminobenzonephenone and Salicylic acid, characterized via FTIR, UV/Vis, 1H-NMR, and 13C-NMR spectroscopy. The melting point of AD4 is 103oC–106oC indicating that it is thermally stable and pure. Gravimetric and potentiodynamic polarization techniques were employed to obtain the corrosion rates (Cr) and percentage inhibition efficiency (%IE) at different concentrations of the inhibitor and at different temperatures. The thermodynamic parameters like Enthalpy, ∆Hoads, Entropy, ∆Soads and free energy of adsorption (∆Gads) of Adsorption were calculated. The Langmuir adsorption isotherm was used to describe the adsorption of AD4 molecules on mild steel. Quantum mechanical calculations were employed to calculate the electronic properties and global reactivity descriptors of AD4. The theoretical results are broadly consistent with experimental results. From the results obtained AD4 could be used as a corrosion inhibition agent in the oil and gas industries.

This study develops a deterministic two-sex compartmental model to investigate the population-level effects of continuous sterile-male releases on Anopheles mosquitoes. The model distinguishes aquatic stages, unmated females, fertile-mated females, sterile-mated females, wild males, and released sterile males, while incorporating density-dependent aquatic recruitment, sex-specific adult emergence, natural mortality, and mating competition between wild and sterile males. We establish the nonnegativity and boundedness of solutions and characterise the wild-mosquito-free and nontrivial wild-mosquito equilibria. The wild-mosquito-free equilibrium is locally asymptotically stable because viable reproduction requires the joint presence of unmated females and wild males, generating a mate-finding Allee effect near extinction. Accordingly, population persistence is characterised by an explicit release-dependent threshold rather than a conventional infectious-disease reproduction number. When the intrinsic demographic condition $\mathcal{Q}>1$ holds, two nontrivial wild-mosquito equilibria may coexist below the critical release rate. Numerical eigenvalue calculations at sampled baseline release levels identify the lower branch as unstable and the upper branch as locally asymptotically stable. A center-manifold/Lyapunov–Schmidt argument establishes a nondegenerate saddle–node bifurcation of the full six-dimensional system at the critical continuous release rate. Numerical simulations are consistent with bistability under subcritical releases and show suppression of the selected established wild population under the sustained supercritical scenarios examined here; these observations are not asserted as a global convergence theorem. For the illustrative baseline parameter set, the critical release rate is approximately 1850 sterile males per day. One-at-a-time and Latin-hypercube/partial rank correlation analyses identify recruitment, maturation, adult survival, sterile-male mortality, and mating competitiveness as major determinants of the release requirement and post-intervention mosquito abundance. Although the numerical threshold is not an operational release recommendation, the framework provides an analytically transparent basis for evaluating continuous sterile-insect interventions and identifying the parameters requiring reliable field estimation.