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    Development of QSAR-based (MLR/ANN) predictive models for effective design of pyridazine corrosion inhibitors
    (Elsevier, 2022) Quadri, Taiwo W.; Olasunkanmi, Lukman O.; Akpan, Ekemini D.; Fayemi, Omolola E.; Lee, Han-Seung; Lgaz, Hassane; Verma, Chandrabhan
    Twenty pyridazine derivatives with previously reported experimental data were utilized to develop predictive models for the anticorrosion abilities of pyridazine-based compounds. The models were developed by using quantitative structure-activity relationship (QSAR) as a tool to relate essential molecular descriptors of the pyridazines with their experimental inhibition efficiencies. Chemical descriptors associated with frontier molecular orbitals (FMOs) were obtained using density functional theory (DFT) calculations, while others were obtained from additional calculations effected on Dragon 7 software. Five descriptors together with concentrations of the pyridazine inhibitors were used to develop the multiple linear regression (MLR) and artificial neural network (ANN) models. The optimal ANN model yielded the best results with 111.5910, 10.5637 and 10.2362 for MSE, RMSE and MAPE respectively. The results revealed that ANN gave better results than MLR model. The proposed models suggested that the adsorption of pyridazine derivatives is dependent on the five descriptors.Five pyridazine compounds were theoretically designed.
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    Effects of heat treatment on the corrosion behavior and mechanical properties of aluminum alloy 2024
    (Elsevier, 2023) El Garchani, Fatima Ezzohra; Lgaz, Hassane; Kaya, Savas; Lee, Han-Seung; Ibrahim, Sobhy M.; Chafiq, Maryam; Ko, Young Gun
    Aluminum alloy, specifically 2024, is extensively utilized in the automotive and aerospace industries due to its light weight and superior mechanical properties. This study explores the corrosion behavior and mechanical characteristics of this alloy following quenching and aging heat treatments. Accelerated corrosion tests involved immersing samples in a salt spray chamber with a 5% NaCl solution, maintained at a temperature of 40 degrees C with a neutral pH. The alloy's microstructure and corrosion behavior were examined before and after the corrosion test, which included a heat treatment at 495 degrees C and aging for five days. Multiple tests, such as Vickers microhardness, optical microscopy, scanning electron microscopy (SEM), and tensile tests were performed. The surface characteristics, specifically the refined microstructure and residual stresses, were analyzed and their impact on localized corrosion was evaluated. The maximum strength value rose from 411 MPa to 512 MPa, and elongation increased correspondingly. Concerning corrosion sensitivity, a reduction was observed in the following order: AA2024-T3 (natural condition), AA2024-T3 (tempered condition), and AA2024-T3 (aged condition). The aged treatment appeared to enhance corrosion resistance, potentially due to the minimized size of corrosion products observed post-etching in various regions. (c) 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).