Central University of Technology
Central University Of Technology Free State - LibraryCUT, South AfricaNot a member yet
2545 research outputs found
Sort by
Malaria In Nata Village, Northern Botswana: Evaluation Of Vector Control Methods
Get PDFThe main aim of this study was three-fold: to determine villagers‟ knowledge about preferences for malaria control interventions; to investigate which mosquito species were prevalent in Nata village, and to determine whether the Plasmodium parasite that is carried by mosquitoes existed in Nata village from the sampled mosquitoes. Nata village is located in the Tutume malaria-endemic sub-district in Botswana. To meet the first aim of the study, interviewer-administered questionnaires which were completed by 109 volunteer participants. To address the second and third aims, Mosquito specimens were collected by using the H-trap and spray sheet collection methods. For the identification of mosquito species, morphological characteristics and molecular analysis techniques were used. Basic taxonomic keys (wings, abdomen, legs, and proboscis) were examined for morphological identification while the polymerase chain reaction (PCR) was mainly utilized for the molecular identification and detection of the Plasmodium parasite in the collected mosquito samples.
A total of 109 participants consented to take part in the study. The majority (65%) of the participants were females and all the participants (100%) claimed to know about malaria control interventions. Only a small group (12%) of these study participants preferred the use of both long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) for sustained use and protection against malaria. Of the 27 mosquitoes used for the morphological analyses, 41% was identified as the Anopheles species while 59% was identified as Culex. Through PCR and the use of species specific primer, no Plasmodium parasites were detected in the DNA of any of the mosquitoes. It was thus established that the mosquitoes in the study area were not infected with the malaria parasite at the time of the study. However, the presence of the possible potential carriers of this parasite in this area suggests that the threat of malaria may still exist.
For molecular identification of the mosquito sample, PCR was conducted with primers targeting CO1, 16S rRNA, and 18S rRNA. Only 16S rRNA was used for further analysis because no significant matches could be found on the NCBI database for CO1 and 18S rRNA sequences. Through phylogenetic analyses, three genera of mosquitoes, namely Anopheles, Aedes and Culex, were identified as prevalent in the study area. Seven mosquito species, including Culex quinquefasciatus, Culex pipiens quinquefasciatus, Culex coronator, Aedes aegypti, Aedes arborealis, Anopheles maculatus, and Anopheles eiseni were identified through phylogenetic analysis that revealed the existence of multiple mosquito species in Nata village. PCR analysis of the samples revealed the presence of vectors of diseases other than malaria. This investigation also elicited knowledge regarding the preferred methods of malaria control initiatives used by the community. This knowledge should be disseminated to support the implementation of environmentally safe malaria control tools and thereby improving the quality of life and health of humans in malaria-prone regions. This study revealed new findings about hitherto unsuspected species of mosquitoes that might co-exist with malaria carrier species or that might even influence malaria distribution in the study area. This is the first report that identified Aedes and Culex genera in Nata village or in the district where the village is situated, and the finding thus calls for further studies to determine the actual role played by these vectors in a malaria endemic area
Effect Of Dietary Inclusion Levels Of Diatomaceous Earth On Production, Carcass Characteristics And Faecal Egg Count Of Lambs
Get PDFThe aim of this study was to assess the effect of different levels of diatomaceous earth (DE) on the growth performance, carcass characteristics and faecal egg counts of lambs receiving feedlot diets. A total number of fifty (50) Ronderib X Merino lambs (male and female) with an average body weight of ± 37 kg were used in this study. The animals were divided on a stratified body weight and faecal egg count (FEC) basis into five (5) groups of ten (10) lambs each, namely; T0, T1, T2, T3 and T4. Animals in all the groups were provided with the same standard feedlot diet that only differs in DE inclusion levels. Diets were formulated to contain DE at four different inclusion levels, namely 0.5% (T1), 1.0% (T2), 1.5% (T3) and 2% (T4) of the diet. T0 (0% DE) served as the control group. The animals were fed two times a day at 07:00 and 16:00 respectively. Faecal samples were taken at two-hour intervals between 8:00 and 16:00 before the start of the project and faecal egg counts were done to determine the average FEC. The sheep were also weighed prior to treatments being applied to allocate the animals to the different groups on a stratified FEC and body weight basis. Body weights of all the animals were recorded weekly, while faecal samples were collected on a two-weekly basis to determine FEC. Eye muscle area (longissimus dorsi) and fat depth were measured at the start and again at the end of the project before slaughtering. After a 46-day feeding period (20 July – 04 September 2017) the lambs were fasted overnight and slaughtered. All carcass traits were recorded for each animal. No significant differences were observed between the different groups in terms of weekly body weights, body weight change (BWC) and average daily gain (ADG). The inclusion of different DE levels did not have a significant effect on most of the eye muscle area, fat depth, carcass and fat measurements. Regarding FEC, there was a general decrease in the roundworm counts from the start to the end of the project, while the coccidia counts showed a general increase. However, the results did not show a positive response in FEC with the inclusion of different levels of DE. From the results of this study, it can be concluded that DE at different inclusion levels did not have a positive effect on most of the measured parameters
Classification Of PM10 And Fall Out Dust Sampling In The Iron Ore Mining Industry, Northern Cape Province Of South Africa
Get PDFIntroduction: Fall-out dust is present in the iron ore mining industry and are generated by open cast mining activities and regulated by legislation. The aim of this study was to determine the concentrations of different dust types deposited at various dust monitoring points.
Methods: Single dust bucket (SDB), and multi directional dust bucket (MDB) methods were used to collect the dust samples. The collected dust was further evaluated for particulate matter smaller than 10 μm (PM10) and analysed for the chemical composition of iron ore fall-out dust with possible impacts on humans and the environment. The influence of environmental parameters on the dust concentrations was also determined. Monitoring was conducted over a twelve-month period. The SDB method was sampled at eight different monitoring points and the MDB method at four monitoring points. Fall-out dust concentrations were determined for all dust sample collections. The sample concentration values were compared to the limit values of the South African National Standard 1929, ambient air quality limits for common pollutants. PM10 monitoring was done at three monitoring points. The chemical analyses of sampled dust for 42 elements was done at an accredited laboratory. The data on environmental parameters used in this study were collected from a centrally located weather station.
Results: The mean dust concentrations for SDB and MDB never exceeded the limit of 600 mg/m²/day for residential areas. The highest level for mean SBD was recorded in November when the wind speed was relatively high. The highest level of mean MDB and mean SDB + MDB fall-out dust where recorded in September. The mean values for SDB, MDB and SDB + MDB were higher from August towards the end of the year as the mean wind speed and relative humidity increased from August. The mean PM10 concentrations never exceeded the limit and the highest level was recorded in February, when the mean wind speed was the lowest with the mean relative humidity the highest of the study period. The highest mean total fall-out dust concentrations of were recorded in September when the predominant wind direction was south south west (SSW). August had the second highest mean total fall-out dust concentration when the wind was predominant in the opposite direction of North. More than 50% of months the wind blows from a predominant multi direction and bi-directional of north west north (NWN) and north east (NE). The mean total PM10 concentration of all the PM10 monitoring points was calculated per month. The fluctuation in the mean total PM10 concentrations per month was limited when the wind directions were multi-directional and bi-directional respectively. Elements with concentrations below the detectable level (BDL) of less than 0.0001 mg/kg had been excluded and only 25 elements are reported on. The results showed that there are only three elements namely calcium, iron and copper that had noticeable higher concentrations than the other elements.
Discussion and conclusion: One of the prominent findings of this study was that the individual buckets of the multi-directional dust bucket did not produce significant differences, making the use of this type of bucket redundant. From the results it could be thus concluded that using single dust bucket systems could be used to monitor in a mining environment. Interestingly, the PM10 concentrations never exceeded the limit in the year of study. Furthermore, concentrations of the chemical elements were within environmental and occupation exposure limits. However, copper and iron demonstrated noticeably high concentrations, with copper and iron concentrations exceeding both the environmental and occupational exposure limits at all sampling points. From this study, it can be concluded that wind direction does not has a major influence on the type of method used for measuring fall out dust. Although the limit was never exceeded, the results indicated that the use of the multi-directional bucket system seems to be redundant. Wind speed has an influence on the rate of PM10 dust particle depending on the monitoring point location in relation to dust producing operations. Applicable legislation is needed to monitor the elemental chemical content of dust when conducting environmental sampling
Consumption of Wild-Growing Vegetables in the Honde Valley, Zimbabwe
Get PDFArticleThis study evaluates the relevance of wild-growing vegetables in two villages of the Honde Valley, Zimbabwe, by documenting the use, knowledge of, and attitudes toward these plants. Information on plant use was gathered through 20 food diaries, 8 focus group discussions, and semi-structured interviews with 76 individuals (32 male) from the villages. Forty-two ethnospecies of wild vegetables were recorded and 26 identified to species. Wild leafy vegetables were consumed about twice a week by participating families; Cleome gynandra and Bidens pilosa were eatenmost frequently. Preferred vegetables were dried and conserved for off-season use. Knowledge of wild food plants was transmitted orally within families, acquired in early childhood, and gradually increased with age. Gender differences were found in the quantity and type of knowledge. According to the villagers, the advantages of wild vegetables were their nutritional and economic value, as well as their accessibility. The perceived drawbacks were mainly related to quality issues, strong tastes, and lack of year-round availability. Despite preference for cultivated alternatives among younger people, there was renewed interest in wild
plants due to recent health concerns such as diabetes and HIV
Optimal Peer-to-Peer Energy Sharing Between Prosumers Using Hydrokinetic, Diesel Generator and Pumped Hydro Storage
Get PDFPublished ArticleIn this paper, an optimal Peer-to-Peer energy sharing model between two small prosumers is developed and
simulated in the south African context. For this purpose, a case study of a commercial type prosumer sharing
power with a residential prosumer, both on the same premise, is used to demonstrate the effectiveness of the
model. The commercial prosumer owns a small hydrokinetic system operating in conjunction with a pumped
hydro storage while the residential prosumer has a diesel generator. The developed model aims to minimize the
resulting cost of energy linked to the diesel generator, while optimizing the power flow between the two prosumers.
Using actual data, the developed model has been used to simulate and analyze the complex interaction
between the different power sources, the energy storage and the demands within the proposed system sizing and
operation constraints. The simulation results show that the power flows can be optimally managed, resulting in a
substantial reduction in the residential prosumer's operation cost which can now rely not only on its diesel
generator but also on the power shared by the hydrokinetic and pumped hydro system of the commercial
prosumer
Topology Optimization and Characterization of Ti6Al4V ELI Cellular Lattice Structures by Laser Powder Bed Fusion for Biomedical Applications
Get PDFPublished ArticleTopology optimization approach was used for the design of Ti6Al4V ELI lattice structures with stiffness and
density close to the human bone for implant applications. Three lattice designs with volume densities of 35 %, 40
% and 45 % and corresponding elastic modulus of 18.6 GPa, 23.1 GPa 27.4 GPa close to the human bone were
generated. Laser powder bed fusion (LPBF) technique was used for the manufacturing of the specimens. Physical
measurements and mechanical characterization of specimens were assessed by microCT analyses and compression
test, perpendicular and parallel to the building direction of the specimens.
LPBF Ti6Al4V ELI manufactured lattice structures showed deviations in wall thickness in comparison with the
generated designs, leading to an increase in relative porosity but also a decrease in elastic modulus in comparison
with the original designs. Horizontal walls of the lattice structures showed higher wall thickness in
comparison with the vertical walls, leading to anisotropic behaviour of the lattice structures. Higher elastic
modulus and compression strength were obtained when thicker walls were oriented along the loading direction
of the compression test, showing a complete failure by dividing the specimens into two neighbouring halves. All
specimens showed 45° diagonal shear fracture along the structure. On the other hand, higher energy absorption
at first maximum compression strength peak was observed when samples were tested parallel to the building
direction (when thinner walls were oriented along the loading compression direction). Results showed that
designed lattice structures can possess the levels of human bones’ stiffness and therefore can reduce/avoid stress
shielding on implant applications
Cost-Effectiveness of Direct Metal Laser Sintered Maraging Steel Inserts For Plastic Injection Moulding Process
Get PDFPublished ArticleThis paper describes an investigation into the possible heat transfer benefits of conformal cooling channels using maraging steel MS1 inserts, which could result in a reduction of cycle times and cost per product, and improve part quality by eliminating defects such as warpage and heat sinks. A manufacturing cost and lead-time comparison showed that a conventionally manufactured insert reached its break-even point after fewer injection moulding cycles than an additive manufactured insert, due to its lower manufacturing costs. During high-volume production, the additive manufactured insert becomes more profitable to use, due to its shorter cycle times
Developing Enterprising Cities in South Africa
Get PDFPublished ArticleCities are considered as engines of economic growth. Enterprising activities in the cities have emerged
as the backbone of the economy of cities across the globe. Efforts have been made in many countries
to build or transform cities to reinforce entrepreneurship and in the process develop enterprising cities.
In the wake of arguments for building enterprising cities in South Africa, this study examined the
dimensions of enterprising cities, the status of cities in terms of entrepreneurial attributes and strategies
essential for building enterprising cities in South Africa. A Delphi research method was adopted for the
study. The study revealed that enterprising cities have distinct dimensions such as economic land scape
(Industrial and service activities), entrepreneurial friendly policy, smart infrastructure (both
transportation and communication), capacity to attract investment, international embeddedness,
research and development and innovation, smart technology, enabled quality communication, and
distinct economic image. The South African cities currently do not portray distinct images of
entrepreneurial cities at both regional or global level. The paper argues that a combination of strategies
for reinforcing economic and social and spatial related entrepreneurial attributes in addition to the
strengthening of entrepreneurship policy for creating an entrepreneurial ecosystem will assist in
creating enterprising cities in South Africa in which tourists as well as locals can find value
The Significance of Indigenous Knowledge Systems (IKS) for Africa’s Socio-Cultural and Economic Development in the Dawn of the Fourth Industrial Revolution (4IR)
Get PDFPublished ArticleConsidering the frictions and tensions about the socio-cultural and economic
development of Africa and the existence of some of tendencies and actions that
are not in favour of the continent’s advancement, the main aim of this article is
to argue for the deliberate reinstatement and retrieval of African Indigenous
Knowledge Systems (IKS). The purpose this argument which in the main is a
political position of an African cultural activist is to motivate for the use of IKS
as a tool for socio-cultural change and economic development strategies that are
vital in the era of globalisation and the Fourth Industrial Revolution (4IR). This
is not new in that as demonstrated by situations of Japan and other Asian
countries, IKS has all the potential to enable the African continent to meet the
challenges of globalisation and chart its future. In addition, the article argues
that the deliberate re-centering of IKS has a potential of complementing the 4IR initiatives with sciences that are embedded in life and work of communities
that are majority in the world and are still depended on the natural resources
that are under threat of diminishing
Managerial Interpersonal Competencies and the Performance of Family-and Non-Family-Owned Small and Medium-Sized Enterprises in Zimbabwe and South Africa
Get PDFPublished ArticleOrientation: Regardless of the contribution done by small and medium-sized enterprises
(SMEs) in modern economies, and the critical role managerial interpersonal competencies play
in sustaining these enterprises, no known comparative study has been conducted in SMEs in
developing economies.
Research purpose: This study purposed to establish the impact of managerial interpersonal
competencies on SME performance as measured by innovation and return on investment
(ROI) in both family-owned SMEs (FOSMEs) and non-family-owned SMEs (NFOSMEs) in
Zimbabwe and South Africa.
Motivations for the study: Efforts at understanding managerial competencies and firm
performance among SMEs have taken a holistic approach, using all known managerial
competencies; yet, recently, there is acknowledgement that interpersonal competencies are
more effective in business sustainability than other competencies. With this observation, the
need to extent this finding in other contexts among FOSMEs and NFOSMEs in developing
countries becomes apparent.
Research approach/design and method: The study whose design was a descriptive
comparative case study adopted a quantitative approach.
Main findings: The study found a positive and significant relationship between managerial
interpersonal competencies and firm performance as measured by innovation and ROI in
FOSMEs in both countries.
Practical/managerial implications: NFOSMEs may need to focus their training on interpersonal
competencies for managers in order to be sustainable. For FOSMEs, continuous enhancement
of managerial interpersonal competencies is important as it promotes innovation and business
sustainability.
Contribution/value-add: The study helps fill the lacuna between research and practice with
respect to managerial interpersonal competencies in FOSMEs and NFOSMEs in the two
countries