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This paper aims to investigate the stability of passive oxide film formed on the surface of 316L stainless steel in 3.5 Wt.% NaCl in the presence of two environmentally non-toxic inhibitors, i.e. leaf extracts of Musa spp. (MS) and Jatropha curcas (JC).

Current transients and potentiodynamic polarization curves were used to explain the stability of the passive film on Current transients and potentiodynamic polarization curves were used to explain the stability of the passive film on 316L stainless steel at both ambient temperature (25 °C) and 70 °C. For the potentiostatic tests, the coupons underwent cathodic stripping to remove the native oxide on their surfaces at −850 mV for 600 s, and a potential of 50 mV was imposed to observe the repassivation for 200 s. For the potentiodynamic tests, the pitting potential measured at 100 μA/cm2, corrosion potential and cathodic current density were obtained for analysis.

The current transients perfectly fitted into the exponential decay curve; i = i_s + i_peak exp(−t/τ), where the decay constant, τ measures the repassivating speed and extent to which the newly formed film heals and stabilizes. The current transients showed that MS and JC help in the repassivating process, especially at 300 ppm and 200 ppm, respectively, both at the lower temperature. The potentiodynamic curves mostly correlated with the current transients except for the hybrid inhibitor. The inhibitors increased the pitting potentials at concentrations that are correlated to their scanning electron micrograph images.

Because they are cheap and environmentally friendly, plant extracts that are proven corrosion inhibitors could be used to aid the formation of passive film on passive alloys in not-so-aggressive environments.

Both MS and JC improve the film stability mostly at intermediate concentrations of 200 and 300 ppm, respectively, at ambient temperature and 70° C.

Using leaf extracts of plants as green inhibitors is considered an environmentally friendly engineering solution.

The leaf extracts are a convenient resource of green inhibitors because their plants are readily available or could be easily naturalized, the processing technique to obtain the extracts is very cheap and the inhibitors are environmentally friendly. In addition, cathodic stripping exposes a relatively larger surface area than that obtained using the most common forms of depassivation; hence, the efficiency of the inhibitor in aiding the formation of the new oxide film to cover the bare surface would be better measured. There is very lean research data on the combined use of green inhibitors and cathodic stripping to study repassivating kinetics of passive alloys.

The purpose of this study was to compare the physico-chemical properties and amino acid profile of three maize hybrid cultivars grown in Nigeria.

Two normal maize endosperm varieties, yellow SUWAN-ISR (YNM) and white ART/98/SW05-OB-WC (WNM), and one yellow QPM variety, TZE-POP-DT-STR-QPM (YQPM), were selected for the study. Physico-chemical properties, physical tests, proximate composition analysis, functional properties and characteristics and amino acid profile tests were carried out on the grains using standard methods.

Protein was significantly higher (p < 0.05) in YQPM (10.49 per cent) than in normal endosperm, YNM (8.83 per cent) and WNM (8.50 per cent). Amino acid profile of the grains revealed that total amino acid of YQPM (94.67 g/100 g of protein) and essential amino acid of YQPM (39.070) were the highest among the three, with highest significantly different value of tryptophan (0.388 g/100 g of protein) at p < 0.05. The cooking quality of YQPM was found to be better than the other two, with highest hydration capacity and increase in volume after cooking (90.8 ± 0.01 g/1000 grains and 147.53 ± 0.02 per cent).

YQPM will be highly beneficial in the tropics, where maize is grown as the major staple food to reduce hunger and malnutrition because of its amino acid balance and its better cooking quality.

Research on the living conditions of slum dwellers in the inner cities of developing countries has received much attention. Nevertheless, there is little empirical research on the influence of personal attributes on the poor environmental condition of the slum area. This study aims to examine the relationship between the socio-economic characteristics and the physical condition of the slum environment in the inner city of Ibadan, Nigeria.

Data was collected through the use of questionnaire administration from a household survey of 491 slum dwellers. Systematic random sampling was used in the selection of the respondents. The study used descriptive, factor and multiple regression to analyse the data collected.

The study used descriptive, factor and multiple regression to analyse the data collected. The study reveals an interplay between various socio-economic factors and environmental conditions. The results show that out of ten (10) socio economic variables that were submitted in the regression model, only eight (8) of these variables such as income, household size, occupation, level of education, age, marital status, year of residency and nativity were significant.

The study concluded that despite the fact that the condition of the slum environment is a product of multiple interrelated factors, personal attributes also contribute to the poor environmental condition of the slum area. The study recommended that improving the socio-economic conditions of slum dwellers would lead to improved environmental conditions.

This study aims to investigate the prevalence of metabolic syndrome (MetS) among people living with HIV (PLWHIV) considering a comparative study.

A comparative cross-sectional study was carried out with 247 respondents which include 123 HIV patients and 124 people without HIV (PWoH) recruited using a simple random sampling method. Anthropometric measurements were taken using the standard procedures and instruments. Systolic and diastolic blood pressure was measured in all the subjects. The lipid level and blood glucose were obtained using a vacutainer method to collect at least 5 ml of venous blood into a heparin-containing bottle and fluoride bottle, and a chemical pathology analysis was conducted at the pathology laboratory.

Using the International Diabetes Federation criteria, the overall prevalence of MetS was 21.1%, while 27.6% and 14.5% prevalence were observed among the PLWHIV and PWoH, respectively. In all, 4% of the respondents were underweight, 40.9% had normal body mass index, 29.6 were overweight and 18.6 were obese I. The mean total cholesterol and triglycerides (TG) for PLWHIV and controls were 162.59 ± 37.80, 177.54 ± 34.23, 91.62 ± 51.74 and 69.59 ± 33.87 mg/dl, respectively. There was no significant association between gender and MetS. Of all the determinants of MetS, central obesity has the highest prevalence (71.5%, 65.3%) among the PLWHIV and the controls. Raised TGs were the components of MetS with the least prevalence (9.8% and 4.8%) among PLWHIV and PWoH. There was a significant association between reduced high-density lipoprotein cholesterol (HDL-C) (p = 0.001) and raised blood pressure (p = 0.001) of PLWHIV and PWoH. This study reveals that the burden of MetS among PLWHIV is higher than apparently healthy individuals.

This study could not measure the association between specific antiretroviral therapy (ART) regimens and MetS because all the PLWHIV in the study are on one regimen Tenofovir disoproxil/lamivudine/dolutegravir. Therefore, longitudinal studies on the extent of ART on MetS should be carried out while using newly diagnosed HIV patients who are not yet on ART as controls.

Prevalence of MetS and its components toward the high range among PLWHIV compared to the PWoH who are apparently healthy individuals was found. Higher prevalence of central obesity and reduced HDL-C among PLWHIV was also found. Overall, MetS is high among PLWHIV, and this might predispose them to adverse metabolic diseases such as cardiovascular diseases, diabetes and kidney diseases among others. Therefore, screening for metabolic risk factors should be adopted as part of routine HIV care.

The findings reveal the magnitude of MetS among PLWHIV compared to the apparently healthy individuals.