Amino-substituted naphthalene sulfonic acid/graphene composite as metal -free catalysts for oxygen reduction reactions

Composites of reduced graphene oxide (rGO) and conducting polymers synthesized from 8-amino-2-naphthalene sulfonic acid (8-ANSA), 5-amino-1-naphthalene sulfonic acid (5-ANSA), 2-amino-1-naphthalene sulfonic acid (2-ANSA), and 4-amino-1-naphthalene sulfonic (4-ANSA) were prepared for use as an electrocatalyst in oxygen reduction reaction (ORR). The electrocatalytic activities were examined in oxygen saturated 0.1 M KOH solution using cyclic and linear sweep voltammetry. The best performing polymer composite was found to be GC/poly(8-ANSA)/rGO, with an enhanced electrocatalytic activity over the rGO only and poly(8-ANSA) only films. More than 100 mV positive shift in the onset potential and 1.6 times increase in current density were observed. The catalytic activity of 2-ANSA, 4-ANSA, 5-ANSA, and 8-ANSA was also validated by density functional theory (DFT). Our calculations predict a much better catalytic activity for 8-ANSA than that of 2-ANSA, 4-ANSA, and 5-ANSA.               KEY WORDS: Poly(amino naphthalene sulfonic acid), Reduced graphene oxide, Oxygen reduction reaction, Electrocatalyst Bull. Chem. Soc. Ethiop. 2019, 33(2), 359-372.DOI: https://dx.doi.org/10.4314/bcse.v33i2.1

Adsorption of Pb(II) ions from aqueous solution using lignin from Hagenia abyssinica

The adsorption of lead(II) ions from aqueous solution onto alkali lignin extracted from Hagenia abyssinica was investigated by electrochemical methods. The effect of solution pH, lignin dosage and contact time were investigated at room temperature in a batch system. Adsorption equilibrium was approached within 80 min. The adsorption kinetics data were described by pseudo-second-order kinetics model, while the equilibrium data were well fitted using the Freundlich model. A maximum adsorption capacity was found to be 80.41 mg g-1 of the dry weight of lignin

Knowledge of reproductive and sexual rights among University students in Ethiopia: institution-based cross-sectional

<p>Abstract</p> <p>Background</p> <p>People have the right to make choices regarding their own sexuality, as far as they respect the rights of others. The knowledge of those rights is critical to youth’s ability to protect themselves from unwanted reproductive outcomes. Reproductive health targeted Millennium Development Goals will not be achieved without improving access to reproductive health. This study was aimed to assess knowledge of reproductive and sexual rights as well as associated factors among Wolaita Sodo University students.</p> <p>Methods</p> <p>An institution-based cross-sectional survey was conducted among 642 regular undergraduate Wolaita Sodo University students selected by simple random sampling. A pretested and structured self-administered questionnaire was used for data collection. Data were entered using EPI info version 3.5.3 statistical software and analyzed using SPSS version 20 statistical package. Descriptive statistics was used to describe the study population in relation to relevant variables. Bivariate and multivariate logistic regression was also carried out to see the effect of each independent variable on the dependent variable.</p> <p>Results</p> <p>More than half (54.5%) of the respondents were found to be knowledgeable about reproductive and sexual rights. Attending elementary and high school in private schools [AOR: 2.08, 95% CI: 1.08, 3.99], coming from urban areas [AOR: 1.46, 95% CI: 1.00, 2.12], being student of faculty of health sciences [AOR: 2.98, 95% CI: 1.22, 7.30], participation in reproductive health clubs [AOR: 3.11, 95% CI: 2.08, 4.65], utilization of reproductive health services [AOR: 2.34, 95% CI: 1.49, 3.69] and discussing sexual issues with someone else [AOR: 2.31, 95% CI: 1.48, 3.62], were positively associated with knowledge of reproductive and sexual rights.</p> <p>Conclusion</p> <p>The level of knowledge of students about reproductive and sexual rights was found to be low. The Ministry of Education has to incorporate reproductive and sexual rights in the curricula of high schools and institutions of higher learning.</p