ABSTRACT Untreated industrial effluents discharged into land and surface water are of great environmental concern. Previous studies on physicochemical characteristics of effluents and sediments from discharged points of various industrial sectors in Lagos metropolis are inadequate in scope, duration, chemical treatment options and estimated pollutant discharge load which are of importance in waste water management. This study was designed to investigate the physicochemical characteristics of ...
ABSTRACT Changes in vegetation or land use that affects soil respiration are a major concern for global climate change. Bush clearing in north-central Namibia has been used as a solution to problems of bush encroachment. However, the effect of bush clearing on soil processes, such as the carbon cycle and soil CO2 efflux has not yet been quantified in Namibia. The main aim of this study was to determine and compare the amount of soil respiration between the cleared and uncleared sites at dif...
ABSTRACT The purpose of this study was to find out the appropriate probability distributions that fit suitable to the motor insurance claims in respect of motorcycles, cars, and heavy vehicle insurance claimed amounts. The specific objectives were: to estimate the probability distributions considered, to identify appropriate model that fit best to the motor insurance claims amounts among eight distributions and to test the goodness of fit of the fitted probability distribution models. Daily ...
ABSTRACT This study aimed at investigating the teaching of Biology and Physical Science practical works in Senior Secondary schools in the Zambezi Region, Namibia. The study was guided by four questions: 1. Did the teaching of Biology and Physical Science practical works in Senior Secondary schools in the Zambezi region follow the learning objectives outlined in the subjects’ curricula?; 2. What practical skills do the Biology and Physical Science teachers aim to achieve from the practical...
Abstract. We generate two new exact models for the Einstein–Maxwell field equations. In our models, we consider the stellar object that is anisotropic and charged with linear equation of state consistent with quark stars. We have a new choice of measure of anisotropy that is physically reasonable. It is interesting that in our models we regain previous isotropic results as special cases. Isotropic exact solutions regained include models by Komathiraj and Maharaj; Mak and Harko; and Misner ...
ABSTRACT Network Vulnerabilities are weaknesses that allow attackers to bypass communication systems or network security. This grants the attackers access to crucial information on victim’s computer systems. So, analysis of network vulnerabilities is highly recommended as it helps to identify them in order to ensure a secured network. The experiments for this study were carried out on three networking environments. The first one was the CIVE LAN (as the main target), the second one was the...
Abstract Stated preference (SP) experiments are becoming an increasing popular survey methodology for investigating air travellers’ choices. Analysis of this behaviour, which is an element of the demand prediction, helps for a better future planning and development of competing airlines. In this thesis, emphasis is stressed on the stated preferences of passengers in choosing between low-cost carriers (LCC) and full-service carriers (FSC). Binary logit and probit model and latent class mode...
This paper considers the estimation of stress–strength reliability when two independent exponential inverse Rayleigh distributions with different shape parameters and common scale parameter. The maximum likelihood estimator (MLE) of the reliability, its asymptotic distribution and asymptotic confidence intervals are constructed. Comparisons of the performance of the estimators are carried out using Monte Carlo simulations, the mean squared error (MSE), bias, average length and coverage prob...
Abstract In this study, natural dye-sensitized solar cells (NDSSCs) were fabricated using crude and purified natural dye extracts aimed at investigating the effect of purified natural dyes on the dye-sensitized solar cell (DSSC) performance. Ethanol and methanol solvents were used to extract natural dyes from Senna singueana flowers, Senna singueana leaves, Ximenia caffra fruits, and Bougainvillea glabra bracts. Liquid-liquid extraction (LLE) method was used to purify the ethanol and methano...
ABSTRACT Depression has been the number one disease, causing a high motility rate in the world, marking the need for new highly effective antidepressants that can alleviate the situation. Unfortunately, the price of carrying out experimentally the whole process of drug discovery and design costs an endeavor billion of money. Yet, computer-aided drug design is a cost-effective way of obtaining new potential drugs within a short period of time. A study helpful in designing potent drug candidat...
ABSTRACT Information on genetic variation of breeding materials helps maintain genetically diversity and sustains long term selection gain. Marama bean [Tylosema esculentum (Burchell) Schreiber] occurs naturally in arid, dry parts of Southern Africa and due to the high nutrient value of the seeds and tubers, rich in protein, oil and starch, is a potential crop for arid areas where few conventional crops can survive. Microsatellites are becoming the molecular marker system of choice because t...
ABSTRACT The purpose of this project was to study the antioxidant potential of selected Namibian Leafy Vegetables (NLV), using Total Phenolic Content (TPC), Total Flavonoid contents (TFC) as well as Diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and Reducing Power (RP) assays. The study also aimed at detecting and characterizing eight phenolic acids (4- hydroxybenzoic, trans-ferulic, vanillic, gallic, syringic, sinapic and para-coumaric acids) ...
The Magombera forest is a home of endemic and endangered biological species such as Udzungwa red colobus monkey (Procolobus gordonorum) and the Magombera chameleon (Kinyongia magomberae). However, the forest is facing high threat of disappearing through resources extraction pressure from adjacent local communities. The project aimed at improving conservation of Magombera forest by involving the adjacent communities through provision of conservation education, restoration initiatives and bee k...
ABSTRACT Kinetic and mechanistic investigations on the reactions of ozone with phenol and some of its derivatives (hydroquinone, catechol, phloroglucinol, pentachlorophenol, pentabromophenol, 1,2- dimethoxybenzene, 1,4-dimethoxybenzene and 1,3,5-trimethoxybenzene) have been carried out. These compounds were chosen, as they can serve as models for compounds which are abundant in surface waters and wastewater. The scope of the investigation was widened by including dihydrogen sulfide, often a ...
Abstract T-cell proliferation studies are traditionally carried out with radioactive reagents or fluorescent reagents that require measurement with advanced technology instrumentation. We attempted to calibrate the optimal conditions suitable for the use of a non-radioactive assay for the measurement of a T-cell proliferation assay in bovine fascioliasis, but applicable to the study of other infectious diseases in our developing 'country setting, Crude antigen extract was prepared from 15 adu...