Open Access Short communication

An Overview of Chemistry Teaching Transformation during COVID-19 Pandemic: An Experience from University of Botswana

Girija S. Singh

Asian Journal of Chemical Sciences, Page 1-6
DOI: 10.9734/ajocs/2021/v10i419097

COVID-19-related disruption in teaching in the University of Botswana led the school to prepare new strategies for running classes and to design innovative way of instruction.  The most notable change was to replace face-to-face lectures with online teaching at least partially (blended teaching and learning). This posed many challenges, especially in the teaching of science and technology subjects. In a laboratory-based discipline such as chemistry the problems encountered were especially daunting.  Moreover, writing mathematical equations, chemical reactions and reaction mechanisms posed their own difficulties.  The present communication provides a brief overview of how chemistry education at the University, the premier national university of Botswana, has been transformed during the last three semesters.  It is based on experience of the author and as judged by the feed-back received from colleagues and the students. Admittedly, the experience is limited and much discussion is still in progress to meet the unresolved challenges. Theory classes at undergraduate levels are now mostly taught online using packages such as Moodle and MS Teams. The tutorial and laboratory sessions have faced the greatest disruptions and the instructors continue to explore ways to conduct these virtually.  Online examinations were found to be limited in their effectiveness, especially in the assessment of drawing chemical structure and reaction mechanisms as well as the students’ ability in scientific writing.

Open Access Original Research Article

Analysis of Pollution Levels of Heavy Elements Using Fractionation Pattern of Street Soils of Langtang North, Plateau State, Nigeria

Lungfa Collins Wuyep, U. F. Hassan, A. A. Mahmoud, T. M. Gudam, M. Siman, Lumi Zakka, Habila Yusuf Thomas

Asian Journal of Chemical Sciences, Page 24-33
DOI: 10.9734/ajocs/2021/v10i419100

Soil Pollution is a serious environmental challenge around the world today. Anthropogenic activities and population explosion have continued to pose great danger to our environment most especially land resources which are fixed. It is against this backdrop that this study assessed the levels of some selected heavy elements (As, Cd, Co, Cr, Cu, Fe, Mn, Ni and Zn). To achieve this, various fractions of exchangeable bound metals, carbonate bound metals, manganese oxide bound metals, iron/manganese bound metals, organic/sulphide bound metals and residual bound metals in soils of Bala, Gantang, She–for, Walang and Yangang Streets as well as Intorok Street which serves as control, Langtang North, Plateau State, Nigeria were assayed using Atomic Absorption Spectrophotometry. The results show that the bioavailable/soluble fractions ranges in (mg/kg) are for: As (BDL – 34.00), Cd (3.00 - 45.00), Co (BDL – 70.00), Cr (42.00 – 155.00), Cu (47.00 – 73.00), Fe (48.00 – 116.00), Mn (46.00 – 119.00), Ni (42.00 – 108.00), Pb (30.00 – 292.00) and Zn (45.00 – 207.00) in all the Streets investigated. The residual/ insoluble fraction ranges in (mg/kg) are for: As (BDL – 5.00), Cd (1.00 – 11.00), Co (BDL – 25.00), Cr (9.00 – 56.00), Cu (11.00 – 19.00), Fe (11.00 – 28.00), Mn (10.00 – 25.00), Ni (10.00 – 21.00), Pb (11.00 – 68.00) and Zn (9.00 – 47.00). The residual fraction is associated with minimal toxicity since migration and transformation of this fraction under general conditions are limited because of being tightly bound to Fe and Mn oxides and hydroxides. The bioavailable fraction is generally observed to be predominant in all the soil, it is usually associated with anthropogenic factors. Higher heavy element concentrations in these streets were recorded in points where there are evidences of organic load discharge and domestic effluents as in the case of Gantang, Yangang, and Bala streets. The fractionation pattern for the six streets assayed showed the northern (hill) part of Langtang North has no potential risk of contamination. However, the plain or southern part of the study area showed high potential risk that if not monitored will result in serious contamination. Topography plays an important role in the risk factor of heavy element contamination in the study area. The overall results showed evidence of some heavy metal pollution in all the Street soils assayed with possible cumulative effect over time.

Open Access Review Article

A Review on Synthesis and Biological Activity of Curcumin and Curcumin Derivatives

. RinaIkhar, Prafulla Sabale, Pravin Kadam

Asian Journal of Chemical Sciences, Page 7-23
DOI: 10.9734/ajocs/2021/v10i419099

Curcumin is a common polyphenolic composite and is the main chemical component of Curcuma longa linn.commonlyknown as turmeric. It is a well-known natural herbal herb traditionally utilized as a flavoring and coloring agent in Indian cooking. Curcumin chemically is diferuloyl methane unit [1,7-bis (4-hydroxy-3- methoxyphenyl)-1,6 heptadiene-3,5-dione] including two ferulic acid residues linked by a methylene bridge. An aromatic o-methoxy phenolic group, α,β-unsaturated β-diketo moiety and a seven carbon linker are essential for the activity. Extensive research gave proof for the role of these various functional groups in its significant biological activities. Due to physiochemical properties such as solubility, stability, bioavailability issues its use is limited in the therapy. To widen its use, various curcumin derivatives and analogs were summarized and assessed for its biological influence. The present review summarisesthe different ways of synthesis of curcumin derivatives with its potential activities that are now in development for the enhancement of bioavailability and therapeutic activity.

Open Access Review Article

Research Progress in the Application of Artificial Neural Networks in Catalyst Optimization

Zhiqiang Liu, Wentao Zhou

Asian Journal of Chemical Sciences, Page 34-46
DOI: 10.9734/ajocs/2021/v10i419101

The catalyst can speed up the chemical reaction and increase the selectivity of the target product, playing an important role in the chemical industry. By improving the performance of the catalyst, the economic benefits can be greatly improved. Artificial Neural Network (ANN), as one of the most popular machine learning algorithms, has parallel processing and self-learning capabilities as well as good fault tolerance, and has been widely used in various fields. By optimizing the catalyst through ANN, time and resource consumption can be greatly reduced, and greater economic benefits can be obtained. This article reviews how CNN technology can help people solve highly complex problems and accelerate progress in the catalytic world.