ABSTRACT
3,3'-Methylenedisalicylic acid (MDS) was synthesized and ascertained on the basis of elemental analyses (C, H) and spectral measurements (IR, mass, 1H NMR, and UV-vis). Moreover, the prepared MDS compound has been assayed for its antimicrobial action against the growth of fungi as well as Gram-positive and Gram-negative bacteria. The results demonstrated the possibility of its usefulness to restrain the growth of both fungi and bacteria, whereas MDS showed its best impact against Candida albicans. The inhibitive impact of MDS on the corrosion of aluminum (Al) in concentrated sodium chloride solution (3.5 wt % NaCl) has been investigated. The corrosion work was done by potentiodynamic cyclic polarization, electrochemical impedance spectroscopy, and chronoamperometric current-time measurements and complemented by scanning electron microscopy and energy-dispersive X-ray investigations. It was found that MDS molecules protect the aluminum against corrosion, and its ability increases with the increase of concentration from 5 × 10-5 to 1 × 10-4 M and further to 5 × 10-4 M. The electrochemical results were supported by the morphological analysis and proved that the presence of MDS inhibits the uniform and pitting corrosion of Al in the chloride solutions.
ABSTRACT
Corrosion of iron in sodium chloride (3.5% wt) solutions and its inhibition by ethanedihydrazide (EH) have been reported. Electrochemical impedance spectroscopy (EIS), cyclic potentiodynamic polarization (CPP), and change of current with time at -475 mV (Ag/AgCl) measurements were employed in this study. Scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) techniques were utilized to report surface morphology and elemental analysis, respectively. The presence of 5 × 10-5 M EH was found to inhibit the corrosion of iron, and the effect of inhibition profoundly increased with an increase in EH concentration up to 1 × 10-4 M and further to 5 × 10-4 M. The low values of corrosion current and high corrosion resistance, which were obtained from the EIS, CPP, and change of current with time experiments, affirmed the adequacy of EH as a corrosion inhibitor for iron. Surface investigations demonstrated that the chloride solution without EH molecules causes severe corrosion, while the coexistence of EH within the chloride solution greatly minimizes the acuteness of chloride, particularly pitting corrosion.
ABSTRACT
The knowledge of the full-energy peak efficiency for a specific source-detector arrangement is often required in various fields of research and applications, such as the analysis of nuclear waste or environmental samples, where both require modeling because it is not practical to prepare a standard that matches the physical and nuclear properties of every waste or environmental item. Therefore, a new numerical algorithm method (NAM) is proposed in the present work to calibrate the co-axial HPGe cylindrical detectors. Cylindrical sources are used in the calibration process placed perpendicularly to the detector's axis. The self-attenuation and the coincidence summing effects at low source-detector distance are also included in the algorithm. A remarkable agreement between the measured and the calculated efficiencies is achieved with discrepancies less than 3%.
