Effect of Aminobenzene Concentrations on the Corrosion Inhibition of Mild Steel in Sulphuric Acid

The inhibiting action of aminobenzene concentration against the corrosion of mild steel in dilute sulphuric acid contaminated with 5% sodium chloride was studied using weight-loss method, calculated corrosion rates from the obtained weight loss data, potentiodynamic polarization measurements and metallographic macrographs. Results show aminobenzene has strong inhibitory effects with inhibitor efficiency increasing with increase in inhibitor concentration at ambient temperature. Maximum efficiency of 99.83% was obtained at 20% concentration of aminobenzene due to adhesion of the inhibitive precipitates through physisorption on the mild steel. This is further justified by the graphs of weight- loss and corrosion rate against exposure which illustrates the corrosion inhibition performance of the inhibitor. Results obtained from potentiodynamic experiments had good correlation with those of the gravimetric methods. The obtained macrographs could also be correlated with the gravimetric method dat

Effects of Nicotiana tobaccum extract additive on the quality of electroplating of zinc on mild steel.

Experimental investigations have been performed to determine the effects of nicotiana tobaccum (tobacco) extract additive on the electrodeposition of zinc on mild steel in acid chloride solution. The experiments were performed under different plating time, different additive concentrations and fi xed pH conditions. Zinc electrodeposition on mild steel was performed using a DC – supply at defi ned operating parameters. The surface of the plated steel was examined using scanning electron microscopy (SEM); and Energy Dispersive Spectroscopy (EDS) for the surface elemental composition analysis. Different surface characteristics were obtained depending upon the concentration of the additive and the plating time. The corrosion resistance of the plated surface was also determined by a gravimetric method. The quality of the electro-deposition of zinc was good as indicated by the microstructural morphology of the plated surface except for the few porosities observed. The electrodeposition process was sensitive to the changes in the additive concentration and plating time. Any variation in the plating parameter produced an entirely new and different surface morphology

Effect of P-Phenylediamine on the Corrosion of Austenitic Stainless Steel Type 304 in Hydrochloric Acid

The effect of P-Phenylediamine on the corrosion behaviour of 304 stainless steel in 3M Hydrochloric acid solution contaminated with 3.5% sodium chloride was investigated using weight loss and potentiostatic polarization techniques. Corrosion parameters such as anodic and cathodic Tafel slope constants, corrosion potential, corrosion current, corrosion current densities, surface coverage and inhibition efficiency were calculated. The polarization measurements indicated that the inhibitors are of mixed type and inhibit corrosion by adsorption on the surface of steel due to the presence of more than one active centre in the inhibitor molecule. The inhibition effect ranged from 38.1% to 81.9% maximum at a concentration of between 0.125% to 1% before dropping sharply to between 9% and 4% at 1.25% to 1.5% concentration. The adsorption obeyed Langmuir adsorption isotherm up to 1% inhibitor concentration

Electrochemical studies of mild steel corrosion inhibition in sulfuric acid chloride by aniline

The corrosion behavior of mild steel in dilute hydrochloric acid under the inhibiting action of various concentrations of aniline was studied using the weight loss and linear polarization resistance technique. The efficiency of the inhibitor increased with the increase in the inhibitor concentration. The results obtained reveal that aniline performed effectively as a corrosion inhibitor. The adsorption mechanism indicates mixed molecular interaction from values of Gibbs free energy. The values of the inhibition efficiency calculated from the two tech- niques are in reasonably good agreement. The adsorption of the inhibiting com- pound was found to obey Langmuir, Frumkin and Freudlich adsorption isotherms. The mechanism of inhibition was discussed in the light of the chemical structure of the inhibiting compound and their adsorption on steel surfaces in relation to the potentiodynamic parameters

Inhibition Effect of N, N'-Dimethylaminoethanol on the Corrosion of Austenitic Stainless Steel Type 304

The effect of N,N'-dimethylaminoethanol on the corrosion of austenitic stainless steel type 304 in 3M H2SO4 has been studied by weight-loss method and linear polarization measurement in different concentrations of the compound. The inhibition efficiencies of the inhibitor compound on the corrosion of the stainless steel were evaluated through assessment of the anodic and cathodic polarization curves of the alloy, the spontaneity of the electrochemical process, inhibition mechanism and adsorption isotherm. The inhibitor efficiency increased with increase in the inhibitor concentration. Results obtained reveal that the inhibitor performed effectively on the stainless steel providing good protection against pitting and uniform corrosion in the chloride containing acidic solutions. The compound act through physiochemical mechanism on the stainless steel surface and obeyed Langmuir adsorption isotherm. The values of the inhibition efficiency calculated from the two techniques are in reasonably good agreement. Polarization studies showed that the compounds behave as mixed type inhibitor in the aggressive media

Audience responses to news media images of Pacific health

News media contain a multitude of images of Pacific peoples and health. This paper presents findings from a social psychological study of audience responses to such images. Two Pacific and two Palagi groups took part in discussions in which they responded to specific print media articles. These discussions were used to explore how different New Zealand audiences view and respond to the portrayals of Pacific people and their health. Responses from the Pacific and Palagi focus groups were compared showing both salience and difference in audience reactions. In appropriating aspects of news coverage, audience members do not simply regurgitate what they are shown by the media. They engage in complex dialogues with other audience members regarding issues raised by media coverage and in the process socially negotiate shared interpretations

Inhibition Effect of Extracts of Carica Papaya and Camellia Sinensis Leaves on the Corrosion of Duplex (α β) Brass in 1M Nitric Acid

The effect of C. Papaya (pawpaw) leaves and C. Sinensis (tea) extracts as an organic „green‟ inhibitor on the corrosion of α β (duplex) brass (65-35% Cu-Zn alloy) in 1MHNO3 (nitric acid) was studied at ambient temperature. Weight loss/corrosion rate and potential measurement techniques were used for the experimental work. The tea extract was obtained from the green tea leaves. The results obtained showed effective corrosion inhibition of the extracts on the brass test specimens in the 1M nitric acid used. The different combined extracts concentrations also gave good corrosion inhibition performance. They also exhibited effective corrosion reactions synergism. The test specimen (duplex brass) gave some appreciable corrosion resistance in the test environmen