Corrosion inhibition of mild steel in 15 wt.% HCl by durum wheat

The toxicity of most commercial corrosion inhibitors and strict environmental legislations have required the development of environmentally-friendly, cheap and non-toxic inhibitors. The use of natural products, especially of plant origin as corrosion inhibitors has become an area of increasing research because plant extracts contain an incredibly rich source of natural chemical compounds which can be extracted by simple procedures at low-cost. Durum wheat was investigated in this work because functional groups were identified which suggested that it could be a promising potential inhibitor. The corrosion of mild steel in 15 wt.% HCl solution with and without Durum wheat was investigated and directly compared to results from two commercial corrosion inhibitors, propargyl alcohol and 2- mercaptobenzimidazole, under the same conditions, by comparing weight loss with and without inhibition. The durum wheat powder and adsorbed films were characterised by Fourier transform infrared spectroscopy (FTIR), and the exposed samples were characterised using SEM, EDS spectroscopy and surface profilometry. The effects of concentration, temperature (20-60°C) and immersion time (5-24 h) on the corrosion inhibition were investigated. Durum wheat was shown to be a successful green corrosion inhibitor with a room temperature inhibition efficiency of 97% (as compared to values of 99% and 97% for propargyl alcohol and 2 - mercapto benzimidazole respectively) and at a lower cost per l L of corrosive solution. However, at the severe corrosive conditions chosen for this research, the inhibition performance of both durum wheat and 2- mercaptobenzimidazole was influenced by time and temperature, and the durum wheat corrosion inhibition was reduced to 78% after 24 hours at 60°C, compared to 88% for 2- mercaptobenzimidazole. All the inhibitors investigated obeyed Langmuir adsorption isotherm

Corrosion inhibition of mild steel in 15 wt% HCl solution by synthetic and green compounds

Registration, Evaluation, Authorization, and restriction of CHemicals (REACH) legislation, in conjunction with Paris Commission (PARCOM) recommendations (1991), are driving research into environmentally friendly alternatives to currently-used corrosion inhibitors. The main focus of this thesis is on compounds of plant-origin because they contain components which can be extracted by simple procedures. These plant extracts are relatively benign in their environmental impact compared to the highly toxic compounds, including propargyl alcohol (PA) and 2- mercaptobenzimidazole (MI), which are currently in use to mitigate the corrosion of oil and gas wells during acidizing treatment. The four ‘green’ corrosion inhibitors, chosen for this research, were extracts from durum wheat (DW), aloe vera gel (AV), inulin (IN; extracted from Jerusalem artichoke), and broccoli (BC). The corrosion inhibition performance of PA, MI, DW, BC, IN and AV for mild steel (MS), immersed in 15wt% HCl solution in the absence and presence of the inhibitors, has been investigated. Weight loss and electrochemical (open circuit potential (OCP), potentiodynamic polarization and linear polarization resistance) were used to determine the corrosion inhibition performance of the inhibitors with a variation of concentration of the inhibitors, solution temperature (20-60°C) and immersion time (5- 192 h). Also, gas chromatography-mass spectrometry (GC- MS) and Fourier transform infrared (FTIR) spectroscopy were further employed to characterize all the chemical compounds to determine their main constituents and functional groups. The as-received MS surfaces were analyzed after immersion in uninhibited and inhibited solutions using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and 3D profilometry. X-ray photoelectron spectroscopy (XPS) was performed to determine the nature and composition of the protective film formed at the MS/HCl solution interface. Potentiodynamic polarization results showed that all the studied inhibitors suppressed both the anodic dissolution of MS and cathodic hydrogen evolution – this implies that they can be classified as mixed- type corrosion inhibitors in the corrosive environment investigated. Concentration studies showed that the corrosion rate of MS decreased with increase in the concentration of all the inhibitors until a point where a further increase in strength did not markedly change the corrosion rate. AV required significant concentration (100 g/L) in the electrolyte to be effective. The study also showed that the corrosion inhibition performance of PA was stable with an increase in temperature (over 99% IE), which indicated that the inhibition performance of PA in 15 wt% HCl was not temperature dependent. However, the corrosion inhibition performance of MI, DW, and BC decreased with an increase in solution temperature. The inhibition performance of IN and AV decreased significantly with the increase in temperature especially at 60°C after 24 h immersion. At 20°C, the corrosion inhibition performance of PA (99%), MI (over 84%) and IN (80%) remained stable with prolonged immersion time (up to192 h). However, DW, BC, and AV decreased slightly at the onset but were later stable throughout the immersion time. The adsorption of both the synthetic and ‘green’ inhibitors onto the MS surface followed the Langmuir adsorption isotherm. Thermodynamic parameters suggested that PA, MI and DW interacted with the MS surface at 20°C via both physical and chemical adsorption, while BC, IN and AV were physically adsorbed onto the MS surface. SEM/EDS examinations revealed that the MS surfaces treated with different inhibitors were less corroded compared to the uninhibited surface. 3D profilometry showed that MS surfaces, after immersion in 15wt% HCl in the presence of various inhibitors, have lower surface roughness values. MS exposed to PA inhibited solution had the lowest surface roughness. XPS studies showed that the studied inhibitors adsorbed at the MS/solution interface, then formed a protective layer. The corrosion inhibition performance of the synthetic inhibitors (PA and MI) were better than the ‘green’ inhibitors for the protection of MS in 15wt % HCl. However, DW and BC performed better than other ‘green’ inhibitors in all the experimental conditions studied. Hence, they may be promising candidate inhibitors. PA performed much better than all the inhibitors investigated, while AV poorly protected MS against corrosion in the environment/conditions studied. The economic analysis of the inhibitors showed that DW and BC were cheaper than the commercial inhibitors (PA and MI), while IN and AV were costlier. The high concentration (100 ml/L HCl) and the cost of AV are pointers that it may not currently be economically viable on an industrial scale

Inhibition of mild steel corrosion using Jatropha Curcas leaf extract

Jatropha Curcas leaf was investigated as a green inhibitor on the degradation of mild steel in 4 M HCl and 4 M H2SO4 aqueous solutions using gasometric technique. Mild steel coupons of dimension 2 × 1.5 cm were immersed in test solutions of uninhibited acid and also those with extract concentrations of 4 ml, 6 ml, 8 ml and 10 ml at 30 oC, for up to 30 minutes. The results showed that as the concentration of the extract increases, there was reduction in the corrosion rate. As the extract concentration increased from 4 ml to 10 ml at 30 minutes exposure, the volume of hydrogen gas evolved decreased from 19.1 cm3 to 11.2 cm3 in H2SO4 medium, while it reduced to 5 cm3 from 9 cm3 in HCl medium. Also, the metal surface-phytoconstituent interaction mechanism showed that 6 minutes is the best exposure time for the adsorption of the extract in both acidic media. The Jatropha Curcas leaf extract was adsorbed on the mild steel surface to inhibit corrosion, while the experimental data obtained at 30 minutes exposure in both acidic media were well fitted with the Langmuir adsorption isotherm. Hence, Jatropha Curcas leaf extract is a good and safe inhibitor in both acidic solutions

Liver mitochondrial membrane permeability modulation in insulin-resistant, uninephrectomised male rats by Clerodendrum volubile P. Beauv and Manihot esculenta Crantz

Background: Non-alcoholic fatty liver disease, which occurs in people who are not alcohol drinkers, describes some of the pathogenic conditions that may be in the least characterized by simple steatosis or can be as serious as non-alcoholic steatohepatitis and cirrhosis. Its mechanistic pathogenesis has been said to arise from insulin resistance and oxidative stress, which may be compounded by obesity. An experimental model showing, systemic insulin resistance, obesity and accumulated hepatic fatty acids was created in adult male rats using high-fat diet manipulation and surgical removal of the left kidney (uninephrectomy). This study sought to identify the impact of these multiple burdens on the liver mitochondrial membrane permeability transition pore opening, and the possible in vitro effects of the extracts of Clerodendrum volubile and Manihot esculenta leaves on the membrane permeabilization. Results: The results indicated that the methanolic extract of Clerodendrum volubile leaf inhibited mitochondrial membrane pore opening in the insulin resistance condition or when it is followed by uni-nephrectomy, while the ethanolic extract of Manihot esculenta leaf does the same in the insulin resistance condition both prior to and following uni-nephrectomy. Conclusion: Since the vegetable extracts were able to abrogate mitochondrial pore opening at low concentrations, the structural integrity of the mitochondria can possibly be restored over time if treated by the vegetable extracts. Research efforts should, therefore, be made to harness the drugability of the bioactives of these vegetables for use in the treatment of non-alcoholic fatty liver disease arising from insulin resistance and renal failure.Fil: Ajayi, Ebenezer Idowu O. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentina. Osun State University; Nigeria. National Institute of Pharmaceutical Education and Research; IndiaFil: Molehin, Olorunfemi R.. Ekiti State University; NigeriaFil: Oloyede, Omotade I.. Ekiti State University; NigeriaFil: Kumar, Vinodu. National Institute of Pharmaceutical Education and Research; IndiaFil: Amara, Venkateswara R.. National Institute of Pharmaceutical Education and Research; IndiaFil: Kaur, Jasmine. National Institute of Pharmaceutical Education and Research; IndiaFil: Karpe, Pinakin. National Institute of Pharmaceutical Education and Research; IndiaFil: Tikoo, Kulbhushan B.. National Institute of Pharmaceutical Education and Research; Indi

Development of a Permeable Meter for Mould Industries Using Locally Sourced Materials

One of the major factors for production of quality casting is the control of properties of moulds and cores to make them uniform and consistent quality. Permeable meter is used for the determination of the venting ability of sand moulds and cores. This testing equipment is being imported to the country as at today. The cost is high, and they are not readily available to foundry operators.Hence there is need to design and develop a permeable meter using locally sourced materials and make it available at an affordable price, thereby improving foundry technology in Nigeria. Two different method could be used to measure permeability of sand; determination of air flow rate and measurement of pressure difference between the orifice and the top of sand specimen. The first method was adopted in the development of the Permeable meter. On testing, the values of permeability measured using the equipment was comparable to the results obtained from thestandardized imported one. The cost of production was 30% of the cost of imported one, not even now that exchange rate to international currency has skyrocketed. The work has incorporated design and fabrication principles that resulted in a relatively cheap product that can be constructed locally by an average Fabricator and Technicia

Dimensions of Vaccination Attitudes in Nigeria: A Study of the Impacts of COVID-19 Vaccine Risk Perception and Acceptance

Nigeria has been affected by the COVID-19 pandemic, and vaccination is a key strategy. However, the country faces vaccination hesitancy, poor risk perception, and low acceptance. This study aimed to assess the direct and interactive impacts of COVID-19 vaccine risk perception and acceptability on COVID-19 vaccination attitudes in the general Nigerian population. In a cross-sectional approach, participants completed a structured questionnaire including demographics, COVID-19 vaccine risk perception, acceptance, and vaccination attitude from April 2-30, 2021. The sample included 1,026 participants from different ethnicities across four regions (Southwest, South, Southeast, and North Central) in Nigeria, which were selected using the convenience sampling method. Multivariate analysis of variance results showed that the COVID-19 vaccine’s risk perception and acceptability have separate and interactive effects on overall vaccination attitudes. Interactively, individuals with high-risk perceptions and low acceptance expressed more skepticism about its benefits, were concerned about its long-term body effects, believed more in its commercialization, and preferred natural immunity. Nigerians’ apprehension about COVID-19 vaccination is impacted by their high-risk perception and low vaccine uptake

Corrosion inhibition of mild steel in 15 wt% HCl solution by synthetic and green compounds

Registration, Evaluation, Authorization, and restriction of CHemicals (REACH) legislation, in conjunction with Paris Commission (PARCOM) recommendations (1991), are driving research into environmentally friendly alternatives to currently-used corrosion inhibitors. The main focus of this thesis is on compounds of plant-origin because they contain components which can be extracted by simple procedures. These plant extracts are relatively benign in their environmental impact compared to the highly toxic compounds, including propargyl alcohol (PA) and 2- mercaptobenzimidazole (MI), which are currently in use to mitigate the corrosion of oil and gas wells during acidizing treatment. The four ‘green’ corrosion inhibitors, chosen for this research, were extracts from durum wheat (DW), aloe vera gel (AV), inulin (IN; extracted from Jerusalem artichoke), and broccoli (BC). The corrosion inhibition performance of PA, MI, DW, BC, IN and AV for mild steel (MS), immersed in 15wt% HCl solution in the absence and presence of the inhibitors, has been investigated. Weight loss and electrochemical (open circuit potential (OCP), potentiodynamic polarization and linear polarization resistance) were used to determine the corrosion inhibition performance of the inhibitors with a variation of concentration of the inhibitors, solution temperature (20-60°C) and immersion time (5- 192 h). Also, gas chromatography-mass spectrometry (GC- MS) and Fourier transform infrared (FTIR) spectroscopy were further employed to characterize all the chemical compounds to determine their main constituents and functional groups. The as-received MS surfaces were analyzed after immersion in uninhibited and inhibited solutions using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and 3D profilometry. X-ray photoelectron spectroscopy (XPS) was performed to determine the nature and composition of the protective film formed at the MS/HCl solution interface. Potentiodynamic polarization results showed that all the studied inhibitors suppressed both the anodic dissolution of MS and cathodic hydrogen evolution – this implies that they can be classified as mixed- type corrosion inhibitors in the corrosive environment investigated. Concentration studies showed that the corrosion rate of MS decreased with increase in the concentration of all the inhibitors until a point where a further increase in strength did not markedly change the corrosion rate. AV required significant concentration (100 g/L) in the electrolyte to be effective. The study also showed that the corrosion inhibition performance of PA was stable with an increase in temperature (over 99% IE), which indicated that the inhibition performance of PA in 15 wt% HCl was not temperature dependent. However, the corrosion inhibition performance of MI, DW, and BC decreased with an increase in solution temperature. The inhibition performance of IN and AV decreased significantly with the increase in temperature especially at 60°C after 24 h immersion. At 20°C, the corrosion inhibition performance of PA (99%), MI (over 84%) and IN (80%) remained stable with prolonged immersion time (up to192 h). However, DW, BC, and AV decreased slightly at the onset but were later stable throughout the immersion time. The adsorption of both the synthetic and ‘green’ inhibitors onto the MS surface followed the Langmuir adsorption isotherm. Thermodynamic parameters suggested that PA, MI and DW interacted with the MS surface at 20°C via both physical and chemical adsorption, while BC, IN and AV were physically adsorbed onto the MS surface. SEM/EDS examinations revealed that the MS surfaces treated with different inhibitors were less corroded compared to the uninhibited surface. 3D profilometry showed that MS surfaces, after immersion in 15wt% HCl in the presence of various inhibitors, have lower surface roughness values. MS exposed to PA inhibited solution had the lowest surface roughness. XPS studies showed that the studied inhibitors adsorbed at the MS/solution interface, then formed a protective layer. The corrosion inhibition performance of the synthetic inhibitors (PA and MI) were better than the ‘green’ inhibitors for the protection of MS in 15wt % HCl. However, DW and BC performed better than other ‘green’ inhibitors in all the experimental conditions studied. Hence, they may be promising candidate inhibitors. PA performed much better than all the inhibitors investigated, while AV poorly protected MS against corrosion in the environment/conditions studied. The economic analysis of the inhibitors showed that DW and BC were cheaper than the commercial inhibitors (PA and MI), while IN and AV were costlier. The high concentration (100 ml/L HCl) and the cost of AV are pointers that it may not currently be economically viable on an industrial scale

Corrosion inhibition of mild steel in 15 wt.% HCl by durum wheat

The toxicity of most commercial corrosion inhibitors and strict environmental legislations have required the development of environmentally-friendly, cheap and non-toxic inhibitors. The use of natural products, especially of plant origin as corrosion inhibitors has become an area of increasing research because plant extracts contain an incredibly rich source of natural chemical compounds which can be extracted by simple procedures at low-cost. Durum wheat was investigated in this work because functional groups were identified which suggested that it could be a promising potential inhibitor. The corrosion of mild steel in 15 wt.% HCl solution with and without Durum wheat was investigated and directly compared to results from two commercial corrosion inhibitors, propargyl alcohol and 2- mercaptobenzimidazole, under the same conditions, by comparing weight loss with and without inhibition. The durum wheat powder and adsorbed films were characterised by Fourier transform infrared spectroscopy (FTIR), and the exposed samples were characterised using SEM, EDS spectroscopy and surface profilometry. The effects of concentration, temperature (20-60°C) and immersion time (5-24 h) on the corrosion inhibition were investigated. Durum wheat was shown to be a successful green corrosion inhibitor with a room temperature inhibition efficiency of 97% (as compared to values of 99% and 97% for propargyl alcohol and 2 - mercapto benzimidazole respectively) and at a lower cost per l L of corrosive solution. However, at the severe corrosive conditions chosen for this research, the inhibition performance of both durum wheat and 2- mercaptobenzimidazole was influenced by time and temperature, and the durum wheat corrosion inhibition was reduced to 78% after 24 hours at 60°C, compared to 88% for 2- mercaptobenzimidazole. All the inhibitors investigated obeyed Langmuir adsorption isotherm