Journals National University of Science and Technology (NUST)
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Using Mathematics to Understand Malaria Infection During Erythrocytic Stages
Get PDFWe review the basic intra-host model of malaria, without immunity. The model describes the Erythrocytic stage in a malaria-infected human, which involves the interaction between malaria parasites and red blood cells. These two populations interact on a dynamic landscape, in which a population of replicating parasites depletes a population of replenishing red blood cells. This paper shows how concepts from nonlinear dynamics can be used to unravel the underlying dynamical features of the model. The intra-host basic reproductive number R0, crucial to calculations concerning control of the infection is calculated. Using mathematical analysis of stability, conditions necessary for reducing and/or clearing parasites in the host are determined. Numerical simulations are also performed to verify analytic results and illustrate the possible behaviour of the model
The Impact of Change in Fashion and Fabrics Coursework Requirements at Ordinary Level: A Case Study of Lower Gweru Schools in Zimbabwe
Get PDFThe study investigated the impact of change in Fashion and Fabrics coursework requirements from two garments to one at Ordinary Level. The study was done in 2011. A case study of four schools in the Lower Gweru cluster in the Midlands province in Zimbabwe was used to ascertain how the change has affected time usage, content coverage and skills exhibited by pupils. The one garment policy was introduced to reduce material costs paid by parents and to lessen the work on pupils. However the benefits of the policy have not translated and to a rise in the number of students registered for the subject. The descriptive survey design was used to collect data from eight teachers, four school heads and four classes of pupils. Data was collected using questionnaires, interviews and focus group discussions. The results indicated that the one garment policy has brought with it benefits such as reduced costs, ample time to finish the coursework garment and time to concentrate on other components of the syllabus. The misconception noted on the requirements of the policy was that pupils were not being exposed to adequate practical work. It is recommended that teachers should increase the number and types of garments made by pupils from Form one to Form four. Parents should also provide practical requirements on time so that pupils and teachers alike may enjoy the benefits of the one garment polic
CHEMICAL PROPERTIES OF JATROPHA SOAP AND ITS EFFECTS ON REACTIVE DYED COTTON FABRICS AS COMPARED TO COMMERCIAL SOAPS
Get PDFJatropha soap has been produced from oil which is obtained from the jatropha curcas. This is an oil-rich drought resistant shrub, originating from Central America but has been grown in many areas of the world including Zimbabwe. This research focuses on comparing the chemical properties of jatropha soap to commercial soaps and its effects on reactive dyed cotton fabrics. Jatropha soap was synthesised in the laboratory and chemical tests were carried out to compare its chemical properties with other commercial soaps. Three commercial soaps, Elangeni, O’key and Perfection soaps were used for comparing the performance of jatropha soap. Tests on alkalinity, solubility, lathering power, cleansing ability, reactivity in hard water and colour fastness to washing were carried out on the soaps. Results indicated that jatropha soap has comparable alkalinity, solubility, cleaning abilityand foaming capacity in soft and hard water like the other commercial soaps. Colour fastness results showed that after washing with jatropha soap and the commercial soaps, there was no colour change on the dyed fabrics thus a rating of 5 was observed on the colour change grey scales. Colour staining was observed on the cotton section of the multifibre after washing with the four soaps and this shows that there may be some slight staining on adjacent cotton fabrics when washing with these four soaps. All the comparison tests indicate that jatropha soap has comparable properties to commercial soaps therefore its local production should be encouraged so as to boost the country’s economy and rural communitie
Dry season pre-impoundment water quality and the effects of anthropogenic activities: The case of Tokwe river, Zimbabwe
Get PDFDamming of rivers and the subsequent increase in human activities bring adverse changes to aquatic systems both downstream andupstream of the impoundment. Changes in physicochemical water quality are one such adverse change usually associated withimpoundments, but, in Africa, no prior characterisation of the water body is usually done to provide baseline data. A pre-impoundment study was carried between July 2013 and July 2015 to assess the water quality of Tokwe River, Zimbabwe, in the cold dry and hot dry seasons. The study also aimed at assessing the effects of anthropogenic activities along the river on water quality and make inferences on the suitability of the water for freshwater aquatic life. Selected physicochemical parameters were assessed in situ using digital meters and in the laboratory using standard methods. There were spatiotemporal differences in water quality attributable to changes in water volume and anthropogenic activities. Except for sulphates and phosphates, there were no significant differences in water quality parameters amongst zones. Sulphates and phosphates were significantly higher in upstream than in inundated and downstream reaches (p < 0.05) whereas TDS, salinity and conductivity were relatively higher upstream than in inundated and downstream zones. Ammonia was higher in upstream and downstream reaches whereas pH was high in inundated area. There were significant (p < 0.05) seasonal changes in temperature, pH, total dissolved solids, salinity, conductivity and ammonia between seasons presumably because of local variations in input from runoff and anthropogenic activities. Major anthropogenic activities observed wereagriculture, bathing, laundry, cattle grazing, and to some extent, mining and veld-fires used in land clearing for farming. The results of this study showed that water quality of Tokwe River was comparable to other rivers and within levels of good quality prior to impoundment and efforts should be maintained to keep it in good health. physicochemical; spatial; temporal; impoundment; inundate
A kinetics study of the treatment of groundwater using commercial activated carbon
Get PDFThe kinetics of groundwater purification obtained from Irrua, Esan Central LGA, Edo State, Nigeria is examined by running the sample at different flow rates through a sediment filter with a commercial granular activated carbon (GAC) adsorbent/filter encapsulated in a cartridge at room temperature. The physicochemical parameters of untreated and treated water samples were determined following standard methods for water and wastewater analysis. Their kinetics were examined using the Lagergren Pseudo First Order as well as Pseudo Second Order models respectively, and their volumetric flow rates rationalized with water quality parameters (DO, COD and BOD). BOD5 results shows that its treatments adequately fits the Pseudo Second Order model with correlation coefficient of 0.967 as against the Pseudo First Order model with a correlation coefficient of 0.578, while treatment of COD fits the Pseudo First Order model having obtain a correlation coefficient of 0.989 as against 0.928 for Pseudo Second Order model. As flow rate decreas es, COD and BOD5 decreases, while DO increases as a result of adsorption. The optimum flow rate determined for groundwater is 111cm3 /min which is in consonance with the contaminant load of the groundwater
High Frequency Mesh Network for Control and Sensor Arrays
Get PDFThis paper explores wireless mesh networking by establishing short-range telemetry links in the Industrial Scientific and Medical (ISM) frequency band of 13.56MHz and demonstrating the forwarding capabilities of a mesh network. For this purpose three transceivers are designed and built which act as nodes on the network, two of which are embedded nodes. The transceivers are designed
Synthesis and In vitro Biological Activity Evaluation of Substituted Chalcones : Chalcones; Claisen-Schmidt Condensation; In vitro Biological Activity.
No full textChalcones and its derivatives are gaining a great deal of attention due to their biological and molecular activities in humans with an ever increasing investigation by in vitro or preclinical studies. In this study, four substituted chalcone derivatives (I-IV) were successfully synthesized using the conventional Claisen-Schmidt condensation between various substituted aromatic ketones and aromatic aldehydes in the presence of aqueous sodium hydroxide. The synthesized compounds gave good yields between 72.5 – 81.8%. In vitro Anti-inflammatory, antimicrobial and antioxidant activities were conducted to evaluate compounds’ pharmacological efficacy. In the anti-inflammatory test, compound 1 was most active which exhibits 20.9 % Membrane Stabilization Effect at 50 mg/mL which is lower than Diclofenac used as the standard. At the concentration of 3.91 µg/mL, compounds III and IV were found to neutralize 50 % of the DPPH free radicals, while the lowest activity was found in compound II at the concentration of 68.7 µg/mL. All the synthesized compounds were found to possess moderate activity against the test organisms when compared to the standards. Chalcones should be explored more as scaffold pharmacophore agents
Dispersion modelling and leachability of heavy metals from tailings dam material of a gold cyanidation plant in Zimbabwe
Get PDFNotable pollution impacts on tailings dams and surrounding areas at gold mines have been a major concern in Zimbabwe. This study investigated the major environmental pollutants propagating from tailings dams in gold operations. Soil and water samples werecollected from a gold mine’s active slimes dam and its surroundings. The samples were analysed for physico-chemical parameters and 13 elements which included; lead, chromium, iron, manganese, nickel, copper, arsenic, cobalt, cadmium, mercury, sodium, cyanide and sulphide. Atomic Absorption Spectroscopy (Varian Spectra AA 200 model) was used in the chemical analysis of heavy metals. In order to determine the relationship between parameters in the tailings dam and seepage (SP) water, a correlation matrix and a panel of regression equations were formulated. Single batch, 24-hour column leach tests were done on the tailings dam soil to ascertain the dissolution and mobility rate of the heavy metals, manganese, arsenic, iron, chromium and lead, under varying pH conditions. Highly positive correlations (> 0.90) were observed between the following pairs; Mn(SP) and Fe (0.99), Mn(SP) and Ammonia (0.96), Mn(SP) and Na (0.92), Fe(SP) and Fe(0.975), Fe(SP) and Ammonia (0.93), Ni(SP) and Fe (0.908), and Ni(SP) and Na (0.92). Relatively weak correlations (<0.50) were found between the following variables: Sulphate(SP) and TDS (0.293), TDS(SP) and Na (0.248), TDS(SP) and Ammonia (0.382), and TDS(SP) and TDS (0.316). The results also showed that heavy metals;manganese, iron and nickel in the see-page water stream have a high correlation value (> 0.80). The findings indicate that theseheavy metals are being released from a common source; dissolution of sulphide minerals within the tailings dam soil.Manganese had thehighest extraction rate across the pH range investigated, having a maximum of 5.8% extraction at pH 3.It was concluded that a pH range of 6 to 9 proved to be the optimum in minimizing the heavy metals solubility
Quantification Of Solid Leather Waste And Waste Mitigation Methods Used In The Zimbabwean Leather Industry: A Case Study
Get PDFThe production processes involved in the manufacture of leather have an adverse negative effect on the environment which can be attributed to the high levels of solid, liquid and gaseous emissions generated during these processes. Literature says that, about 75% out of a tonne of raw hides is not utilised but remains as waste. Of the generated waste approximately 50% is considered hazardous as the waste is mainly from tanning and post tanning operations and thus may contain chromium. It is in this regard that a study was carried out to quantify the levels of solid waste being generated as well as the waste mitigation efforts being used, if any, in the Zimbabwean leather industry. This study analysed the actual processes performed in some of the still functioning tanneries in Zimbabwe in order to propose tannery solid waste management practices. The main aim of this study therefore, was to gather accurate and useful data of the nature and amount of solid waste generated during leather making operation from raw hides and skins input to finished leather. To achieve these goals, 3 tanneries were visited across Zimbabwe. This enabled to have a first-hand experience and also facilitated an in-depth study of the chosen facilities. A diagnostic industrial survey was conducted using both quantitative and qualitative methods. From these findings, it was clear that there exists a gap in waste mitigation in Zimbabwean tanneries and therefore there is a need to educate tanners on the advantages of introduction of such schemes for the benefit of the environment. Also huge costs are incurred in the disposal of the solid waste therefore introduction of recovery and recycling projects may be of greater advantage to the tanners
Zimbabwe’s print media coverage of Gender Based Violence: An analysis of the factors influencing journalists’ coverage of Gender-Based Violence issues
Get PDFPurpose: This paper interrogates factors influencing journalists' coverage of Gender-Based Violence (GBV) in the Global South, specifically in Zimbabwe. The study analyses mainstream daily newspapers the Chronicle and NewsDay, is motivated by the numerous pressing GBV issues and cases affecting Zimbabwe, chief among them child marriages, sexual abuse, and domestic violence, largely against women. Therefore, the expectation is that with all these challenges on women and children, GBV stories will dominate the front pages of newspapers and airwaves in Zimbabwe as the media plays its role of mitigating the negative perceptions on issues of gender-based violence.
Methodology: The study adopted a qualitative research approach and utilised qualitative content analysis for the news articles and in-depth interviews with journalists and editors.
Findings: The study reveals that there is generally low coverage of GBV stories in both media, with rape dominating such stories. Further, law enforcement officers are major sources in GBV stories, rather than the victims. Key factors identified include lack of prioritisation of GBV stories by newsrooms, lack of journalistic skills to cover GBV issues, and a culture of silence within society on such issues.
Originality: Combining journalistic agency, the social construction of reality, and political economy of media theories in this paper helps unravel how gender-based violence issues remain absent in the order of priorities within Zimbabwean newsrooms, leading us to conclusions that GBV remains de-prioritised rendering the media ineffective in the fight against the GBV