Investigating Concrete Steel Rebar Degradation Using Some Selected Inhibitors in Marine and Microbial Media

Potential monitoring investigations were conducted on concrete steel rebar samples premixed with selected inhibitors accompanied by fixed amount of sodium chloride salt and partially immersed in sulphuric acid and sodium chloride solution. Varying concentration of potassium dichromate, potassium chromate and sodium nitrite inhibitors were used individually and synergistically in this study. The potential readings were taken in accordance with ASTM C 876 through the open circuit potential corrosion monitoring technique. Suppressive quality and dependability of the inhibitor was then assessed by the Weibull probability density distribution as an extreme value statistical modeling approach to study performance effectiveness and forecast the most effective inhibitor concentration in each media. Inhibitor effect on the compressive strengths of the reinforced concrete samples was also examined and reported. Results showed that 0.15M potassium chromate inhibitor had the best overall and individual performance in its inhibiting ability in the H2SO4 medium, while 0.68M sodium nitrite admixture was predicted as showing the lowest probability of corrosion risk in NaCl medium. Also, the best synergistic performance was shown by sample admixed with 0.06M K2Cr2O7, 0.15M K2CrO4 and 0.27M NaNO2 partially immersed in the NaCl medium. The compressive strength of concrete sample admixed with 0.03M K2Cr2O7 and 0.10M K2CrO4 was the highest amongst samples admixed with inhibitor in both media, though the control sample partially immersed in the NaCl medium had the highest overall compressive strength value

Phytochemical Screening and in vivo antioxidant activity of Ethanolic extract of caesalpinia bondus (L.) Roxb

Phytochemical screening, antioxidant activity in vivo and lipid peroxidation of 75 % ethanolic extract of young twigs and leaves of Caesalpinia bonduc were carried out by chemical test, and assessment of catalase and peroxidase activities and lipid peroxidation in Wistar rats after oral administration of different concentrations of the plant extract for ten days. Phytochemical screening of the extract revealed the presence of all major classes of phytochemicals: tannins, flavonoids, saponin, steroids, terpenoids, cardiac glycosides, glycosides, except phlobatannins. There were significant (p<0.05) graded increase in catalase and peroxidase activities and decrease in TBARS concentrations in the extract tested rats in comparison with normal control, Vitamin C and amodiaquine tested rats. The various pharmacological activities of C. bonduc may be due to its antioxidant activity

Aniline effect on concrete steel rebar degradation in saline and sulfate media

Electrochemical potential monitoring experiments were performed on mild steel rebars embedded in concrete admixed with aniline inhibitor and fixed amount of sodium chloride salt partially immersed in sulfuric acid and sodium chloride solution. The open circuit potential corrosion monitoring technique was employed and the potential readings were taken in accordance with ASTM C 876. Repressive attribute and consistency of the inhibitor was then estimated by the Weibull probability density distribution as an extreme value statistical modeling approach to study performance effectiveness and to predict the most efficient inhibitor concentration in each media. Aniline effect on the compressive strengths of the reinforced concrete samples was also investigated and reported. Varying concentrations of the inhibitor were used and its performance improved as concentration changed in NaCl medium, while no particular order of performance was noted in sulfuric medium. In the statistically analyzed experimental results for each of the inhibitor concentrations employed, 0.34 and 0.41 M aniline admixed samples were identified as exhibiting the best inhibiting quality in sodium chloride while 0.14 M aniline was predicted as showing the lowest probability of corrosion risk in sulfuric acid medium. The overall effective inhibitive performance in sulfuric acid was less when compared to the sodium chloride medium. Concrete sample admixed with 0.41 M aniline had the highest improvement in compressive strength in both media

Aniline effect on concrete steel rebar degradation in saline and sulfate media

Electrochemical potential monitoring experiments were performed on mild steel rebars embedded in concrete admixed with aniline inhibitor and fixed amount of sodium chloride salt partially immersed in sulfuric acid and sodium chloride solution. The open circuit potential corrosion monitoring technique was employed and potential readings were taken in accordance with ASTM C 876. Repressive attribute and consistency of the inhibitor was then estimated by the Weibull probability density distribution as an extreme value statistical modeling approach to study performance effectiveness and predict the most efficient inhibitor concentration in each media. Aniline effect on the compressive strengths of the reinforced concrete samples was also investigated and reported. Varying concentrations of the inhibitor were used and its performance improved as concentration changed in NaCl medium, while no particular order of performance was noted in sulfuric medium. In the statistically analyzed experimental results for each of the inhibitor concentrations employed, 0.34 and 0.41 M aniline admixed samples are identified as exhibiting the best inhibiting quality in sodium chloride while 0.14 M aniline was predicted as showing the lowest probability of corrosion risk in sulfuric acid medium. The overall effective inhibitive performance in sulfuric acid was less when compared to the sodium chloride medium. Concrete sample admixed with 0.41 M aniline had the highest improvement in compressive strength in both media

A Framework for M-Commerce Implementation in Nigeria

The Internet has brought about the concept of grobalilation, which has revolutionized the way business is transacted all over the world. The E-comnterce is of particular interest, though widely used but still has some security challenges in terms of transparency and confidentiality of transactiorts. This papei focuses on M-contnrcrce as an extensiott to E-commerce hnplementatiott with the Bankiltg industry proposed as core implementation consideration in ortler to guarantee high level security. We have reviewed some cqses of onlilrc frauds and eliscussed tlte emerging critical issues afficting software development of M-cornmerce applicatiotts. Afranrcworkfor M-commerce implementationis therefore,proposed for countries such as Nigeria, Romania and Indonesia where cases of online scam are alanning

Topological characterization of neutron star crusts

Neutron star crusts are studied using a classical molecular dynamics model developed for heavy ion reactions. After the model is shown to produce a plethora of the so-called "pasta" shapes, a series of techniques borrowed from nuclear physics, condensed matter physics and topology are used to craft a method that can be used to characterize the shape of the pasta structures in an unequivocal way

Ophthalmic disorders among students of School for the Deaf

Aim: This study aimed at determining the prevalence and pattern of ophthalmic disorders amongstudents of School for the Deaf, Akure, Ondo State, Nigeria.Methodology: This is a cross sectional descriptive study was conducted in October, 2011 aspart of activities marking the Annual Physicians’ week of Nigerian Medical Association (NMA),Ondo State. Ethical clearance was obtained from the Ethical Review Committee of FederalMedical Centre, Owo prior to commencement of this study. The permission of the SchoolAuthority was also obtained before the commencement of this study. The respondents wereselected by simple random sampling technique. All enrolled participants were interviewed withthe aid of the study instrument (questionnaire) by the authors and interpreters (school teachers).Results: The respondents comprised of 91(56.9%) Males and 69 Females (43.1%). Nearly all therespondents;158(98.8%) were deaf and dumb. Most respondents; 116(72.5%) had ocularexamination in the past. Few respondents; 118(73.75%) had ophthalmic disorder. The commonest ophthalmic disorder was refractive error which was found in 16 respondents(38.1%). Myopia was diagnosed in 9 respondents.CONCLUSION: Most of the respondents were deaf and dumb. Few respondents hadophthalmic disorder. The commonest ophthalmic disorder was refractive error. Myopia was themost predominant refractive error. There is need for periodic ocular screening and treatment atthe School for the Deaf.