Looking Inwards for Sustainability: Nigerian Cities and Building Demolition-waste or wealth?

Cities could generally be described as sustainable before the replacement of manual labour with machines known as the industrial revolution of the 18th century in Europe. Nevertheless, the Industrial Revolution has been associated with environmental degradation and other negative impacts. The trend continued for two centuries until it was realised that there is a limit to the capacity of the earth to withstand such impacts. The damage to the earth needs to be halted by choice or forced by natural consequences. The idea of pursuing economic development with minimum negative socio-economic and environmental impacts comes to be known as Sustainability. The built environment becomes at the centre of the sustainability agenda due to the enormous negative impact to the environment. Moreover, it was reported that 90% of all materials resources ever extracted might be used in the built environment. Unfortunately, many of these materials, including 10% unused are discarded as wastes. In the UK example, 90-120 million tonnes of construction and demolition (C&D) waste is generated annually. This makes C&D wastes even more critical to the sustainability agenda; and in search for solution, in the words of Janine Benyus, it may even involve the urban westerners learning from the wisdom of the preindustrial societies that have been living in harmony with the nature. In the preindustrial community of Kano in Nigeria, there is virtually zero C&D waste; rather it is merchandise. The different categories of the stakeholders were interviewed to establish how the system works, the conditions that led to its emergence, and limitations. It was discovered that the end-of-life management of buildings in Kano is a naturally evolved industrial ecology analogous to the natural ecological system, whereby the bye-product of one process becomes the raw material for another with no waste. Furthermore, a conceptual model of the system was developed using the biomorphic adaptation of the shell of an African snail. It was therefore argued that sustainability practices are inherent within the African traditions rather than to be learnt from outside

Heavy metals phytoremediation using Typha domingensis Flourishing in an industrial effluent drainage in Kano, Nigeria

Phytoremediation as a tool employs aquatic macrophytes as a principal and inexpensive strategy for controlling environmental pollution. It is achieved through various mechanisms such as phytoextraction, phytostabilization, and phytovolatilization. In this study, heavy metal content of a contaminated drainage that empties into the Kano River was investigated by assessing the uptake of heavy metal contaminants by a notorious aquatic weed, “Typha domingensis”. Atomic Absorption Spectrophotometer (AAS) was used to determine the concentration of Pb, Cu, Zn, Cr and Fe in the effluent, sediment and T. domingensis in the months of January, April and July 2013, covering the seasonal weather pattern in the area. In addition, the Bioconcentration factor (BCF) of these metal pollutants in T. domingensis, were calculated as the ratio of their concentration in Typha domingensis to the effluent while the Transfer factor (TF), as the ratio of these substances in T. domingensis to the sediment. From the results, Cu, Fe and Zn concentrations were statistically different (p<0.05) in the effluent as well as in the sediment across the sampling months, while Pb and Cr were significant only in the sediment. The BCF values obtained for these metals in the test plant were >1 except for Fe in April, which indicates the plant capacity for phytoextraction. Similarly, TF values obtained were >1 except for Pb, Fe and Cu in the months of January, April and July respectively. This also indicates the potentiality of T. domingensis as a nutrient and metalaccumulating plant through the process of sequestration. The findings of this work have demonstrated the capacity of T. domingensis in the effluent drainage, not only playing an ecological role in the environment, but also to remove heavy metal pollutants. Therefore, the plant species could be used for phytoremediation of industrial effluent contaminating ecosystems.Keywords; T. domingensis, phytoremediation, Heavy metals, industrial effluen

Upgrading n-Heptane via Catalytic Hydroisomerisation

An atmospheric pressure upgrading of n-heptane was carried out in a temperature range of 300 to 450oC over an in situ developed molybdenum carbide phase supported over sulphated zirconia. Although a decreased in surface area with increased in pore volume were observed after carburization, the physicochemical data showed no noticeable alteration to the zirconia structure or the sulphate species. The catalyst formed a good system with high selectivity to iso-heptanes under either low temperature or high space velocity. It therefore has promising features that could offer mitigation to some of the challenges faced by the petroleum refineries with noble metals promoted zeolites. Keywords: n-heptane, hydroisomerisation, carbide catalyst, stability, sulphated zirconia

Phytochemical properties and antibacterial activities of the leaf and latex extracts of calotropis procera (ait.f.) Ait.f.

A comparative preliminary study on the phytochemistry and antibacterial effects of ethanolic and aqueous extracts of the leaves and latex of Calotropis procera on four pathogenic clinical bacterial isolates namely Escherichia coli, Staphylococcus aureus, Salmonella species and Pseudomonas species was carried out using paper-disc diffusion and broth dilution techniques. The results obtained revealed that ethanol was the best extractive solvent for a fraction with antibacterial properties of the C. procera leaves and latex. Generally, the aqueous extracts showed no activity on the isolates. The minimum inhibitory concentration (MIC) for the leaf ethanolic extract was 1000 – 2000 μg/ml while the minimum bactericidal concentration (MBC) of the latex ethanolic extract was 2000 μg/ml. Phytochemical analysis of the leaf and latex extracts showed the presence of tannins, steroids, saponins and flavonoids while alkaloids were absent in both extracts. Generally, the antibacterial effects of the plant parts revealed that the leaf extracts had stronger activity in comparison with those of the latex

Production of Liquefied Petroleum Gas (LPG) Range Alkanes from n-Octane via Catalytic Hydroconversion

The production of light range alkanes with potentials as LPGs was carried out at 1 atm pressure over a range of reaction temperatures using both in situ and ex situ prepared molybdenum carbide supported sulphated zirconia catalysts. The in situ synthesized material formed the best system in terms of stability, conversion and selectivity to desired reaction products, as well as resistance to thermal treatment. This suggests its prospects as industrial material. Mechanistically, the reaction was believed to involved the participation of both the carbide and the sulphated zirconia surfaces via hydrogenolysis and hydrocracking, respectively. Reactions over the carbide formed mainly methane whereas propane and butanes could significantly be obtained over the sulphated zirconia. Keywords: n-octane, hydroconversion, light gases, fuel, prospect

Total Phenolic and Flavonoid Contents, Antioxidant Activity and Phytochemical Screening of Calotropis Procera Stem Bark Extracts

Communication in Physical Sciences 2020, 5(3): 233 Authors: Abdullahi Usman, Ruth O. Onore, Osebuohien A. Oforghor, Jibrin Mohammed, and Nasiru L. Usman Received 19 May 2020/Accepted 29 May 2020 In continuation of the need to search for phytochemicals in parts of some rare and native plants of Nigeria origin. This study was designed to carry out phytochemical screening, antioxidant properties and determination of total phenolics and flavonoid contents in Calotropis procera Stem. The phytochemical screening of stem bark of C. procera using aqueous and methanol extracts revealed the presence of tannins, phenols and flavonoid. The aqueous extract was also found to contain saponins while methanol extract also has steroids. Steroids was the only metabolite present in hexane extract. The anti-oxidant activity, total phenolic and flavonoid contents of aqueous and methanolic extracts of stem bark of C. procera were evaluated by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, Folin-Ciocalteau and aluminium chloride colorimetric assays. From the results obtained, the methanolic extract was observed to have demonstrated a significant concentration of phenolic (81.65±0.92 mg GAE/g), and flavonoid (46.08±0.71 mg RE/g) than the aqueous extract (66.07±0.43 mg GAE/g, 31.34±0.39 mg RE/g). The aqueous and methanol extracts showed maximum activities of 28.16±0.64% and 81.65±0.71% at 1 mg/ml respectively. However, the ascorbic acid exhibited 83.12±1.02% in the DPPH assay. The results of the present study, shows that both aqueous and methanolic extracts could serve as a valuable source of natural antioxidants

Robust Input Shaping for Sway Control of an Overhead 3D Crane

This paper presents a robust input shaping control of an overhead 3D crane. Control of a crane in the presence of wind disturbance during payload hoisting is extremely challenging, as hoisting with wind disturbance causes high unwanted payload sway, which makes payload positioning difficult to achieve. Two robust input shaping techniques are presented, the zero vibration derivative-derivative (ZVDD) and extra insensitive (EI) shapers. Simulations using a nonlinear 3D overhead crane model were performed and the performances of the two robust input shapers are compared. In these investigations a wind disturbance force of magnitude 0.3 N is considered for the robustness test, in addition different payload mass were tested. It is predicted that the method can be very useful in reducing the complexity of closed-loop controllers for both tracking and sway control

Waist Circumference, Waist Hip Ratio and Body Mass Index in Female Undergraduates of a Tertiary Institution in Nigeria: a Cross-sectional Study

Purpose: Obesity and overweight are associated with variety of conditions detrimental to health, wellbeing and longevity. Waist circumference and waist to hip ratio are indicators of risk of central adiposity while body mass index is an indicator of overall risk of obesity. Body mass index has been traditionally used as a standard for determining overweight and obesity. This study was designed to determine the relationship between waist circumference, waist to hip ratio and body mass index among female undergraduates of a Nigerian University. Also prevalence of obesity based on waist circumference, waist to hip ratio and body mass index was explored. Methods: Three hundred and sixty four apparently healthy subjects were recruited for the study using a cross-sectional simple random sampling technique. Waist circumference, waist to hip ratio and body mass index were determined using standard methods. Descriptive statistics were used to summarize the physical characteristics of the participants. Pearson correlation coefficient was used to analyze the relationship between waist circumference, waist to hip and body mass index. Results: The mean age, waist circumference, waist to hip ratio and body mass index of the participants were 22.5 (±2.20) years, 79.36 (±10.4) cm, 0.81 (±0.06), and 22.48 (±4.50) kg/m2 respectively. The prevalence of obesity based on body mass index, waist circumference and waist to hip ratio was found to be 6.3%, 17.6% and 25.5% respectively. Significant relationship was found between waist circumference and body mass index (r = 0.81; p\u3c 0.001), and between waist to hip ratio and body mass index (r = 0.25; p\u3c 0.001). Conclusions: Body mass index was related to waist circumference, as well as to waist to hip ratio. The prevalence of obesity based on waist to hip ratio was highest among female undergraduates in a Nigerian university. Awareness on the importance of waist to hip ratio as indicator of risk of obesity should be created among female undergraduates in Nigerian Universities and by extension among the women population in general

Global impacts of scientific publications by academic staff: a case study of College of Medical Sciences, University of Maiduguri, Nigeria

The impacts of scientific research by an individual or institution are measured using various bibliometric indices such as the h-index and citations index among others. Objective: The present study assessed the global impacts of scientific publications by academic staff of the College of Medical Sciences, University of Maiduguri (CMS-UNIMAID) using selected bibliometric indices. Methodology: The data (demographic data, research experience, and the number of publications) of the 202 academic staff of College of Medical Sciences CMS-UNIMAID were obtained from the records submitted for the 2019/2020 annual appraisal. The h-index, citations index (CI), number of documents (ND), RG score, research interest (RI), citation/item, and citation/year of the staff were extracted from Google Scholar, Publons, ResearchGate, and Scopus using th authors search until 25 December 2020. Staff and publication online visibilities were determined. Descriptive statistics were prepared for all records obtained and subjected to appropriate inferential statistics. Results: The mean age and research experience of the staff were 45.4±9.2 and 13.9±9.6 years, respectively. The majority (p<0.05) of the staff were male (85.1%), had a PhD/Professional Fellowship (61.4%), and were senior academic staff (53.5%). Atotal of 4940 publication entries were submitted for the appraisal. Only 2.5% of the staff were visible on all platforms with staff online visibility of 63.9, 55.5, 15.8, and 5.0% (p<0.05) on Scopus, ResearchGate, Google Scholar, and Publons, respectively. Male staff (68.0%) were more visible (p<0.05) than their female counterparts (40.0%) on Scopus while senior academic staff were more visible (p<0.05) than junior academic staff on all platforms except Publons. Publication online visibility was highest (p<0.05) in Google Scholar (78.4%) and ResearchGate (65.9%) than Publons (28.0%) and Scopus (25.1%). The mean h-index, CI, and ND were 8.3±1.1, 401.8±97.8, and 36.2±4.9, respectively on Google Scholar and 5.0±0.4, 166.4±25.6 and 9.0±0.9, on ResearchGate. Publons showed means h-index, CI, and ND of 5.0±0.3, 77.2±13.7, and 25.6±2.1, respectively while Scopus showed 4.0±1.6, 144.4±95.3, and 14.5±6.2, respectively. In addition, the means RG score and RI were 10.0±0.7 and 113.1±15.4, respectively while the means citation/item and citation/year were 3.9±1.7 and 10.7±6.8, respectively. Conclusions: Low bibliometric indices indicate poor global impact of scientific publications from CMS-UNIMAID. Concerted efforts are required to improve the quality of research and publication through adequate funding, infrastructure, and mentorship among others