134 research outputs found
Theoretical and Experimental Inhibitive Properties of Mild Steel in HCl by Ethanolic Extract of Boscia senegalensis
The experimental aspect of the corrosion inhibition potentials of Boscia senegalensis was carried out using gravimetric and linear polarization techniques techniques as well as scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), whereas the theoretical aspect was done by using the Density functional theory (DFT) calculations to performed and model the electronic structures of some extract constituents, including Physiosorptive interactions with the Fe surface. The analyses of the experimental results showed that the inhibition efficiency increased with increase in concentration of the inhibitor and decreased with increase in temperature. The efficiency of the extract in HCl (70%). Thermodynamic parameters revealed that the adsorption of extract onto the metal surface was spontaneous, exothermic and supported the Physical adsorption process. FTIR results showed that the inhibition mechanism was by absorption process, through the functional groups present in the extract and that of the inhibited. Surface morphology also revealed that corrosion product confirmed the protection offered by the extract on the surface of the metal immersed in the acid media. The data obtained were fitted into various adsorption isotherms though the Freundlich isotherm was found to be best fit. Keywords: Inhibition, density functional theory, corrosion, boscia senegalensis
Application of aqueous extracts of coffee senna for control of mild steel corrosion in acidic environments
Electrochemical and microbial treatment of bromophenol blue dye in aqueous solution
Bromophenol blue (BB) is an important triphenylmethane derivative widely used in research and industry as a dye or colorant for silk, leather, and drugs. BB has a high proclivity for water contamination because of its high solubility and stability, causing damage to living organisms even in low quantities. This study assessed the feasibility of electrochemical and biological for the decolorization of BB using graphite-copper electrode and indigenous microorganisms, respectively. It was found that effectiveness of electrochemical treatment improves with higher electrolysis time, current density, and electrolyte concentration, drops with rising pH, and shows a nonlinear pattern with temperature. The microbial strains identified as Acinetobacter baumaniu, Serratia marcescens, Aspergillus niger, Aspergillus flavus, Bacillus megaterium, Rhizopus stolonifer, and Bacillus subtilis performed poorly, irrespective of the dye/mineral salt ratio. The electrochemical technique was much more effective for decolorizing bromophenol blue dye-contaminated water. The computational results showed clearly that bromine atoms are the most susceptible sites for attack by oxidizing species and, thus, the onset of BB-decolorization
Dimensions of Entrepreneurial Competencies of Agribusiness Managers in Niger Delta Region of Nigeria
Challenges to business survival in developing regions have been noted to be different from those in the developed regions of the world. Thus, the competencies among the business managers in these regions differ considerably in magnitude and direction over eighteen traits that can influence the quality of performances technically; shortfall or proficiency of managers hinges on the quality of exhibition of these traits. Within this context, it became imperative to investigate the attributes of the enterprise managers who have successfully managed their enterprise over challenging business environment. This study assessed the entrepreneurial competencies of agribusiness operators in the Niger Delta Region of Nigeria. A sample size of 85 respondents were selected through snowballing sampling procedure from bakery and restaurant enterprises. Data collected were analyzed using factor analysis. Results reveal that competencies like proactively, networking, and self-efficacy, willingness to take risk, creative thinking and willingness to learn were being possessed by the firm managers. According to the results, it is of utmost importance for entrepreneurs to develop some specific competencies in order to obtain a higher performance.
Keywords: Competency, Entrepreneurial, Agribusiness, Food, Processors, Managers, Dimension
Protection of Mild Steel Corrosion in Sulphuric Acid Environment Using Wheat Starch
Abstract. The corrosion of mild steel in 0.5 M H 2 SO 4 acid solution and the inhibition process by wheat starch (WS) was investigated using weight loss and potentiodynamic polarization measurement techniques respectively. Gravimetric results revealed that there is significant reduction in the corrosion rate of mild steel in the presence of inhibited solution compared to blank solution, and also the inhibition efficiency was found to depend on the concentration of the WS. Data on potentiodynamic polarization results confirmed that WS exhibited mixed type inhibition behaviour, though the cathodic effect was more pronounced. The mode of WS adsorption on the corroding metal surface followed Langmuir isotherm model. In addition, the trend of inhibition efficiency with temperature, activation energy and heat of adsorption parameters revealed a strong interaction between the WS constituents and the corroding metal surface, thus indicating that WS lowered the corrosion process by blanketing the mild steel surface through chemical adsorption mechanism. The mechanism of inhibition was discussed in the light of the chemical structure of starch
Microbial metagenomic approach uncovers the first rabbit haemorrhagic disease virus genome in Sub-Saharan Africa.
Rabbit Haemorrhagic Disease (RHD) causes high morbidity and mortality in rabbits and hares. Here, we report the first genomic characterization of lagovirus GI.2 virus in domestic rabbits from sub-Saharan Africa. We used an unbiased microbial metagenomic Next Generation Sequencing (mNGS) approach to diagnose the pathogen causing the suspected outbreak of RHD in Ibadan, Nigeria. The liver, spleen, and lung samples of five rabbits from an outbreak in 2 farms were analyzed. The mNGS revealed one full and two partial RHDV2 genomes on both farms. Phylogenetic analysis showed close clustering with RHDV2 lineages from Europe (98.6% similarity with RHDV2 in the Netherlands, and 99.1 to 100% identity with RHDV2 in Germany), suggesting potential importation. Subsequently, all the samples were confirmed by RHDV virus-specific RT-PCR targeting the VP60 gene with the expected band size of 398Â bp for the five rabbits sampled. Our findings highlight the need for increased genomic surveillance of RHDV2 to track its origin, understand its diversity and to inform public health policy in Nigeria, and Sub-Saharan Africa
Review of forms of corrosion and mitigation techniques: A visual guide
Over the years, issues relating to corrosion have been a serious challenge confronting effective scientific and engineering applications of metallic materials in the industry. Annual loss due to corrosion issues has been quite alarming as it runs into trillions of dollars. In this review, forms of corrosion, factors affecting each form, mechanism of formation, and different aggressive environments that propagate corrosion have been identified. Mitigation techniques against this threat were all discussed, especially those involving the use of eco-friendly, cheap, available, and non-toxic materials. It was observed that the principle, process, and conditions governing each form of corrosion must be well understood before it can be effectively mitigated. This can be done either by proper material selection and design, environmental measures, modification and engineering design, modification of corrosive media, use of inhibitors, or sacrificial and protective coatings. However, adequate knowledge of the environment and nature of metal to be deployed in such an environment is essential in ensuring such material's protection, safety, and durability. For efficient and effective corrosion prevention and control, these mitigation techniques can either be implored exclusively or collectively depending on the material's nature and the setting in which it will be used
Adsorption and corrosion inhibition characteristics of 2–(chloromethyl) benzimidazole for C1018 carbon steel in a typical sweet corrosion environment: Effect of chloride ion concentration and temperature
Benzimidazole derivatives are emerging as promising corrosion inhibitors for oil and gas application because
they exhibit high efficiency and very good environmental profile. Although long alkyl and phenyl chains enhance
their efficiency, they also increase their toxicity. Finding benzimidazole derivatives devoid of long hydrocarbon
chains and with lower toxicity has become a priority. 2–(chloromethyl)benzimidazole (CMB), with log Po/w =
2.2, has been investigated as a promising low-toxic sweet corrosion inhibitor for C1018 carbon steel in
CO2–saturated NaCl solution under static condition using experimental and theoretical approaches. At 25 ◦C,
Open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization
(PDP) techniques confirm that CMB is an anodic-type sweet corrosion inhibitor which is able to form a protective
layer on the steel surface and provide inhibition efficiency of 97.54% at 10 ppm. The efficiency increased to
98.40% and 98.58% upon increasing the temperature to 40 â—¦C and 60 â—¦C, respectively but decreased to 96.32%
and 94.76% as the salt concentration was raised to 5.0% and 7.0% NaCl, respectively. The latter was attributed
to the antagonistic competition between Cl– ions and CMB for anodic adsorption. The CMB–steel interaction is
facilitated by the free electrons around N heteroatoms and C = C bonds, based on FTIR analysis and computational calculations. This eventually ameliorates the surface degradation of the steel during the sweet
corrosion at 25 and 60 â—¦C. CMB performance is highly comparable with reported sweet corrosion inhibitors with
higher toxicity values
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