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Papers by Ahmed Mohammed
Journal of Advanced Concrete Technology, 2012
ABSTRACT
Chemical mitigation is regularly used as one of the principal prevention and control techniques i... more Chemical mitigation is regularly used as one of the principal prevention and control techniques in reinforcement corrosion. Hence this study presents the effect of toluene and dioctylphthalate on the rebar corrosion of medium carbon steel in seawater and cassava fluid with a view to determining inhibitive potentials of the different inhibitors in the two media. Gravimetric and voltametric techniques were employed in this study and a total of forty-five corrosion coupons of different dimensions were produced. Forty coupons were used for gravimetry and the remaining five for corrosion potentials measurements. Eight of the samples were used as control; while other eight samples were admixed with dioctylphthalate and toluene in concrete cubes. It was later immersed in seawater and cassava fluid for a total duration of 32 days and the measurements were taken at interval of 4 days in order to determine the corrosion rates in mils per year (mmpy). Two controls and admixed samples were later immersed in seawater and cassava fluid, respectively, for durations of thirty-two days to determine the corrosion potentials using a voltmeter and a Copper-Copper Sulphate Electrode (Cu/CuSO 4 ). The pH of each medium was also measured throughout the period of exposure. The results obtained showed that all the samples except the control samples, displayed some degree of inhibition. The inhibition levels for the admixed samples in seawater were on the higher side compared with those in cassava fluid. The inhibition efficiencies for different inhibitors followed different trends in different environment. The inhibition efficiencies for toluene in cassava fluid and seawater were 21.64% and 45.78% respectively. The study concluded that organic inhibitors were effective in inhibiting corrosion in cyanide and chloride contaminated concrete cubes.
Revista Matemática Iberoamericana, 2000
We prove a Harnack's inequality for non-negative solutions of some degenerate elliptic operators ... more We prove a Harnack's inequality for non-negative solutions of some degenerate elliptic operators in divergence form with the lower order term coefficients satisfying a Kato type condition.
Communications in Partial Differential Equations, 1998
Bulletin of the Australian Mathematical Society, 2000
The American Mathematical Monthly, 2005
... Shif Berhanu and Ahmed Mohammed ... (We will see in section 4 that C does, in general, depend... more ... Shif Berhanu and Ahmed Mohammed ... (We will see in section 4 that C does, in general, depend on A and B as well as on a and b.) Alex Harnack (1851-1888) first introduced inequality (1.2) in his book Grundlagen der Theorie des Logarithmischen Potentials (Leipzig, 1887). ...
Journal of Advanced Concrete Technology, 2012
ABSTRACT
Chemical mitigation is regularly used as one of the principal prevention and control techniques i... more Chemical mitigation is regularly used as one of the principal prevention and control techniques in reinforcement corrosion. Hence this study presents the effect of toluene and dioctylphthalate on the rebar corrosion of medium carbon steel in seawater and cassava fluid with a view to determining inhibitive potentials of the different inhibitors in the two media. Gravimetric and voltametric techniques were employed in this study and a total of forty-five corrosion coupons of different dimensions were produced. Forty coupons were used for gravimetry and the remaining five for corrosion potentials measurements. Eight of the samples were used as control; while other eight samples were admixed with dioctylphthalate and toluene in concrete cubes. It was later immersed in seawater and cassava fluid for a total duration of 32 days and the measurements were taken at interval of 4 days in order to determine the corrosion rates in mils per year (mmpy). Two controls and admixed samples were later immersed in seawater and cassava fluid, respectively, for durations of thirty-two days to determine the corrosion potentials using a voltmeter and a Copper-Copper Sulphate Electrode (Cu/CuSO 4 ). The pH of each medium was also measured throughout the period of exposure. The results obtained showed that all the samples except the control samples, displayed some degree of inhibition. The inhibition levels for the admixed samples in seawater were on the higher side compared with those in cassava fluid. The inhibition efficiencies for different inhibitors followed different trends in different environment. The inhibition efficiencies for toluene in cassava fluid and seawater were 21.64% and 45.78% respectively. The study concluded that organic inhibitors were effective in inhibiting corrosion in cyanide and chloride contaminated concrete cubes.
Revista Matemática Iberoamericana, 2000
We prove a Harnack's inequality for non-negative solutions of some degenerate elliptic operators ... more We prove a Harnack's inequality for non-negative solutions of some degenerate elliptic operators in divergence form with the lower order term coefficients satisfying a Kato type condition.
Communications in Partial Differential Equations, 1998
Bulletin of the Australian Mathematical Society, 2000
The American Mathematical Monthly, 2005
... Shif Berhanu and Ahmed Mohammed ... (We will see in section 4 that C does, in general, depend... more ... Shif Berhanu and Ahmed Mohammed ... (We will see in section 4 that C does, in general, depend on A and B as well as on a and b.) Alex Harnack (1851-1888) first introduced inequality (1.2) in his book Grundlagen der Theorie des Logarithmischen Potentials (Leipzig, 1887). ...