The purpose of this paper is to originally present the generic analytical models of memelement and inverse memelement with time-dependent memory effect.
Abstract
Purpose
The purpose of this paper is to originally present the generic analytical models of memelement and inverse memelement with time-dependent memory effect.
Design/methodology/approach
The variable order forward Grünwald–Letnikov fractional derivative and the memristor and inverse memristor models proposed by Fouda et al. have been adopted as the basis. Both analytical and numerical studies have been conducted. The applications to the candidate practical memristor and inverse memelements have also been presented.
Findings
The generic analytical models of memelement and inverse memelement with time-dependent memory effect, the simplified ones for DC and AC signal-based analyses and the equations of crucial parameters have been derived. Besides the well-known opposite relationships with frequency, the Lissajous patterns of memelement and inverse memelement also use the opposite relationships with the time. The proposed models can be well applied to the practical elements.
Originality/value
To the best of the authors’ knowledge, for the first time, the models’ memelement and inverse memelement with time-dependent memory effect have been presented. A new contrast between these elements has been discovered. The resulting models are applicable to the practical elements.
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Abdelaziz S. Fouda, Mohamed A. Ismail, Rabab M. Abou-shahba, Walaa A. Hussein, Esraa S. El-habab and Ashraf S. Abousalem
The purpose of this paper is to investigate three Arylfuranylnicotinamidine derivatives against corrosion of carbon steel (C-steel) in 1.0 M HCl by chemical and electrochemical…
Abstract
Purpose
The purpose of this paper is to investigate three Arylfuranylnicotinamidine derivatives against corrosion of carbon steel (C-steel) in 1.0 M HCl by chemical and electrochemical means. The inhibition efficiency (%IE) increases with increasing the dose of inhibitors. The tested compounds exhibited improved performance at elevated temperature, with %IE reaching 93 percent at 21 µM. Tafel polarization method revealed that the tested compounds act as mixed-type inhibitors. The inhibition action was rationalized due to chemical adsorption of inhibition molecules on C-steel surface following Temkin’s isotherm. Surface examination was carried out by AFM and FTIR techniques. Further, theoretical chemical approaches were used to corroborate the experimental findings.
Design/methodology/approach
Experimental and computational methods were applied to investigate the efficiency of these new compounds. These studies are complemented with spectral studies and surface morphological scan by AFM. The theoretical results indicate good correlation with experimental findings.
Findings
The tested derivatives are promising corrosion inhibitors for C-steel in the acid environment. The molecular scaffold of this class of compounds can be used to design new highly efficient inhibitors by screening its activity by modeling studies.
Originality/value
The studied compounds are safe inhibitors and greatly adsorbed on Fe surface. The action of compounds is enhanced with temperature, which means these compounds can be used in higher temperature systems. The new compounds are effective at very low concentration.
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A.S. Fouda, S.S Elkaabi and A.K. Mohamed
The inhibitive effect of some substituted phenyl n‐phenylcarbamates on corrosion of iron in 2N HCI have been studied using gaivanostatic polarization measurement. Studies carried…
Abstract
The inhibitive effect of some substituted phenyl n‐phenylcarbamates on corrosion of iron in 2N HCI have been studied using gaivanostatic polarization measurement. Studies carried out with different concentrations of the inhibitor indicated that the compounds act as a mixed inhibitor. The results indicate that the additives reduce the corrosion rate by way of adsorption through the oxygen atom of phenoxy group and nitrogen atom of NH group. The inhibitory character of the compounds depends upon the concentration of the inhibitor, as well as its chemical composition. The results of electrocapillary measurements are consistent with the electrochemical measurements. Thermodynamic parameters for absorption of inhibitors have been calculated and discussed.
A.A. Al‐Suhybani and I.H. Al‐Hwaidi
Introduction The corrosion of iron has been extensively studied in various media. In nitric acid solutions, the corrosion of iron is much faster than in other mineral acids at…
Abstract
Introduction The corrosion of iron has been extensively studied in various media. In nitric acid solutions, the corrosion of iron is much faster than in other mineral acids at comparable concentrations. This is attributed to an autocatalytic process involving some nitrogen oxides, nitrous acid and/or some iron complexes. At high nitric acid concentrations, passivation of iron takes place. The factors affecting the dissolution and the passivation processes are not fully understood. The effect of various inhibitors on the corrosion of iron in acid media has been studied. Thus Ammar et al. have studied the passivation of iron and the effect of some anions, e.g. Br− and I− on the passive film. The effect of amides as inhibitors for iron in nitric acid has been reported by Fouda and Gouda. These authors have found that the corrosion process is controlled by the reaction of amides with HNO3 and not by the surface reaction. The effect of aniline and some aminobenzoic acids on the rate of corrosion of iron has been reported. The present work is aimed at examining the efficiencies of some aniline substitutes as corrosion inhibitors for the corrosion of iron in concentrated nitric acid solution.
The purpose of this paper is to compare the suitability of fractional derivatives in the modelling of practical capacitors. Such suitability refers to ability to provide the…
Abstract
Purpose
The purpose of this paper is to compare the suitability of fractional derivatives in the modelling of practical capacitors. Such suitability refers to ability to provide the analytical capacitance function that matches the experimental ones of each fractional derivative.
Design/methodology/approach
The analytical capacitance functions based on various fractional derivatives of both local and nonlocal types including the author’s have been derived. The derived capacitance functions have been simulated and compared with the experimental ones of aluminium electrolytic and electrical double layer capacitors (EDLCs).
Findings
This paper has found that any local fractional derivative with fractional power law-based relationship with the conventional one is suitable for modelling the aluminium electrolytic capacitor (AEC) by incorporating with the conventional capacitance definition. On the other hand, the author’s nonlocal fractional derivatives have been found to be more suitable than the others for modelling the EDLC by incorporating with the revisited definition of capacitance.
Originality/value
The proposed comparative analysis has been originally presented in this work. The criterion for local fractional derivative, to be suitable for modelling the AEC, has been found. The nonlocal fractional operators which are most suitable for modelling the EDLC have been derived where the unsuitable one has been pointed out.
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Emad ElDin El-Katori and Nady Hashem
The purpose of this paper is to minimize corrosion-related pollution in the environment. From the lemongrass extract (LGE), the authors selected one of the best green inhibitors.
Abstract
Purpose
The purpose of this paper is to minimize corrosion-related pollution in the environment. From the lemongrass extract (LGE), the authors selected one of the best green inhibitors.
Design/methodology/approach
The corrosion and inhibition of mild steel in traditional acidification solutions were estimated by electrochemical measurements. The corrosion appearance was observed with scanning electron microscopy, atomic force microscopy micrographs and attenuated total reflectance infrared spectroscopy spectrum. The correlation was formed between the gained inhibition efficiency (IE)% from electrochemical measurements and certain quantum chemical parameters.
Findings
The results displayed that the IE was up to 90% when the LGE concentration was 300 ppm. The results confirmed that the theoretical experiments are very similar to the experimental observations.
Originality/value
For the first time, LGE was used as a cheap and safe corrosion inhibitor for mild steel corrosion in the acidification process. The mechanism of mild steel corrosion and anti-corrosion in acid solution has been suggested.
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Samy Shaban, Abd Elaziz Fouda, Mohamed Elmorsi, Tarek Fayed and Omar Azazy
The purpose of this study is to inspect the corrosion inhibition of API N80 steel pipelines in uninhibited solution and inhibited with a synthesized surfactant compound…
Abstract
Purpose
The purpose of this study is to inspect the corrosion inhibition of API N80 steel pipelines in uninhibited solution and inhibited with a synthesized surfactant compound [N-(3-(dimethyl octyl ammonio) propyl) palmitamide bromide] (DMDPP), which is prepared through a simple and applicable method.
Design/methodology/approach
Weight loss was inspected at five different temperatures of 25°C, 30°C, 40°C, 50°C and 60°C Potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation were used at room temperature. Density functional theory was used to study the relation between the molecular structure and inhibition theoretically.
Findings
Adsorption of the prepared DMDPP fits the Langmuir isotherm model. The inhibition efficiency of the prepared DMDPP amphipathic inhibitor is directly proportional to temperature increase. Polarization results reveal that the investigated DMDPP amphipathic compound behaves as a mixed-type inhibitor. EIS spectra produced one individual capacitive loop.
Originality/value
The originality is the preparation of cationic surfactants through a simple method, which can be used as corrosion inhibitors in oil production. The synthesized inhibitors were prepared from low-price materials. The work studied the behavior of the synthesized surfactants in inhibiting the corrosion of the steel in an acidic medium. Electrochemical and theoretical studies were presented, besides gravimetric and surface examination.
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A.S. Fouda, A. Abd El‐Aal and A.B. Kandil
To show the effect of organic compounds containing O and N atoms on the corrosion inhibition of Cu in HNO3 and; the effect of some donating substituent groups on the corrosion…
Abstract
Purpose
To show the effect of organic compounds containing O and N atoms on the corrosion inhibition of Cu in HNO3 and; the effect of some donating substituent groups on the corrosion inhibition.
Design/methodology/approach
A range of published papers (1956‐1995), which aim to discuss the effect of organic compounds on the corrosion inhibition process. Two methods were used to determine the rate of corrosion, these methods were weight loss and polarisation. The effect of temperature and concentration were studied. The thermodynamic parameters for the process were computed and discussed.
Findings
Provides information about weight loss and polarisation methods and how to prepare the Cu samples before and after tests. This will provide many academics relevant information before teaching or researching duties.
Research limitation/implications
The paper may be using withdrawing substituting groups in addition to donating groups, this will improve the discussion, also the paper does not use the technique of impedance spectroscopy for comparison.
Practical implications
To use Cu alloy for comparison and to use other compounds with larger molecular weights.
Originality value
The use of some phthalimide derivatives as corrosion inhibitors for Cu in HNO3, provide more information on Cu corrosion for academic researchers and provide practical help for starting researchers.
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A.S. Fouda, S.A. EL‐Sayyad and M. Abdallah
The purpose of this paper is to investigate the inhibiting properties of four N‐3‐hydroxyl‐2‐naphthoyl hydrazone derivatives in 0.5 M H2SO4 solution and to study the mechanism of…
Abstract
Purpose
The purpose of this paper is to investigate the inhibiting properties of four N‐3‐hydroxyl‐2‐naphthoyl hydrazone derivatives in 0.5 M H2SO4 solution and to study the mechanism of their action.
Design/methodology/approach
The effect of various parameters on the behavior of these inhibitors has been studied using the weight loss and polarization measurements.
Findings
The inhibiting action of the investigated compounds depends primarily on their concentration and molecular size. The compounds act as mixed type inhibitors and function via adsorption on carbon steel surface, which follows Frumkin adsorption isotherm. The addition of KI, KBr and KSCN to N‐3‐hydroxyl‐2‐naphthoyl hydrazone derivatives had a synergistic effect in enhancing the efficiency of corrosion inhibition.
Originality/value
This paper provides useful information regarding inhibition effect of N‐3‐hydroxyl‐2‐naphthoyl hydrazone derivatives and clarifies the role of the molecular structure and substituents on the inhibition efficiency of these investigated compounds on the corrosion of carbon steel in acidic solutions.
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M.M. El‐Tagouri, M.R. Mostafa, H.M. Abu El‐Nader and G.M. Abu El‐Reash
The efficiency of some 2‐heterocarboxaldehyde‐2′‐pyridyl‐hydrazones as inhibitors for the acid dissolution of Al was studied by mass loss, hydrogen evolution and polarization…
Abstract
The efficiency of some 2‐heterocarboxaldehyde‐2′‐pyridyl‐hydrazones as inhibitors for the acid dissolution of Al was studied by mass loss, hydrogen evolution and polarization measurement techniques. The corrosion rate was measured in 2M HCI at different temperature and concentrations; maximum percentage protection (85%) was obtained at 103M for the compound containing oxygen atom. The activation energies were calculated for all the additives used. The rate constant decreases as the inhibition efficiency increases. The results show that the studied materials influencing both the cathodic and anodic process. The mechanism of inhibition was proposed on the basis of the formation of a protective monolayer by the inhibitors molecules on the metal surface according to Langmuir isotherm.