33074 research outputs found
Sort by
Factors that influence distributor satisfaction within multi-level marketing in South Africa
Get PDFJournal Article, Faculty of Economic and Management Sciences, Workwell: Research Unit for Economic; Management Sciences-- Potchefstroom CampusPurpose of the study: Limited research has been done in South Africa’s MLM industry, particularly pertaining to distributor satisfaction and the factors that influence distributor satisfaction. This study aims to determine the factors that influence distributor satisfaction within multi-level marketing (MLM) in South Africa.
Design/methodology/approach: The study considered existing literature and was quantitative and descriptive in design. Non-probability convenience sampling was used to draw the sample through self-administered online questionnaires via Google Forms, which resulted in a total of 376 questionnaires collected for data analysis from distributors of health and wellness MLMs in South Africa.
Findings: A standard linear regression analysis was also conducted. Results indicated that the method of diffusing business opportunity, the perceived quality of the recruitment process and the perception of products and services predict distributor satisfaction within health and wellness multi-level marketing (MLMs) in South Africa. Recommendations/value: It is crucial for health and Wellness MLM businesses in South Africa to improve their distributor satisfaction.
Managerial implications: Health and wellness MLM businesses in South Africa who want to improve their distributor’s level of satisfaction can focus on improving the method of diffusing business opportunities and aim to improve the perception that the distributors have of the recruitment process as well as products and services
Prediction of the minimum ignition energy of dust clouds based on heat transfer and particle reaction kinetics
Get PDFJournal Article, Faculty of Natural and Agricultural Sciences, Material Science Innovation and Modelling (MaSIM)-- Mahikeng CampusA numerical model for the calculation of the minimum ignition energy (MIE) of dust clouds is developed based on heat transfer and particle reaction kinetics. The model is an update of previous models relying on the experimental minimum ignition temperature (MIT) of dust clouds. Gas and particle temperature profiles during the spark ignition processes are studied in detail to generate dust cloud MIE prediction. For the 20 dusts studied, with the updated model, the average calculated MIE over experimental MIE ratio is 81.6%, a significant improvement compared with the ratio of 48.1% using a previous model with the MIT. A strong correlation is found between the dust cloud MIE and the MIE of the nearest particle to the spark center in the dust cloud: for all the studied dusts, the latter accounts for over 85% of the dust cloud MIE. Moreover, the minimum spark ignition temperature of a dust particle (SITP) can be defined, which also strongly correlates with the dust particle MIT (MITP) calculated using the Semenov theory. Based on these correlations, simple MIE predictive equations are derived and validated by comparing their MIE predictions with the experimental MIE data.Acknowledgements
The authors gratefully acknowledge the financial contribution from China Scholarship Council (201806030181) and China Postdoctoral Science Foundation (2023M743777)
School Principalship Leadership and Management in Integrated Muslim Schools in South Africa: An Investigation
Get PDFJournal Article, Faculty of Education, Educational Leadership (Edu-Lead)-- Potchefstroom CampusThis research focused on strategies for effective leadership and management in integrated Muslim schools. A qualitative approach within a phenomenological design was utilized to encapsulate qualitative data on the strategies for effective
leadership and management in integrated Muslim schools. Nonprobability sampling methods were employed, and in-depth, semi-structured interviews were used as the primary method to capture the data from the participants. The main findings from this research identified invaluable insights into the nature of integrated Muslim schools from a historical perspective, the governance, bodies of membership and registration of these schools and the existing leadership and management portfolio. The research established that the school principals presiding over leadership and management of integrated Muslim schools have a dichotomous portfolio of leadership and management, that is, the secular curriculum and the Islamic curriculum. Thus, they have dichotomous leadership and management tasks, primarily toward their employers and as a religious duty. Furthermore, it was established that these leadership and management duties are not detailed, which results in role ambiguity and overlapping between the leadership and management role on the one hand and the governance role of school principals on the other
Creation of near infrared spectroscopy calibration algorithms for soil water content prediction
Get PDFMaster of Science in Environmental Sciences, North-West University, Vanderbijlpark CampusWater is arguably the most important human resource, and fresh water is becoming increasingly scarce. Irrigation in agriculture is one of the most water-demanding sectors, which urges the importance of effective management decisions within this sector. Conducting accurate measurements of soil water content is paramount in making productive decisions in agricultural water management. The problem, however, is those traditional methods of water content measurement in soils, are expensive and immobile. Methods such as the neutron probe is required to calibrate for each soil type and carries a health hazard for users. Additionally, tensiometers and electrical resistance probes are stationary and cannot be relocated to measure different areas. Near infrared spectroscopy (NIRS) can provide a solution to the need for a rapid, accurate, and cost-effective method for measuring soil moisture content. A calibration model is however needed by NIRS in order to make sense of observations. There are unfortunately no such freely available calibration models for South African soils. This study aimed to create such calibration algorithms for soil water content and dry bulk density (DBD) predictions on approximately 213 soil core samples taken at predetermined locations in five catchments in South Africa. Algorithms were also created to compare to the only freely available calibrations algorithms from the Open Soil Spectroscopy Library (OSSL). The samples were scanned with a portable, handheld NeoSpectra NIR scanner at different moisture contents, which was achieved by saturating the samples and then placing them in pressure chambers to gradually reduce the moisture, at pressures of 33 (Drained upper limit), 100, 500, and 1500 kPa (lower limit). At each scan the soil was weighed to determine the gravimetric water content, which was later converted to volumetric water content using the bulk density. Calibration algorithms were then created on the R coding platform using the spectral data and were compared against the lab-determined volumetric water content. The calibration algorithms were trained on 75% of the dataset, selected by K-means clustering on the spectra. Calibration algorithms were created using Random Forest, Cubist, and Partial Least Squares machine learning algorithms and various pre-processing methods including Savitzky-Golay, Multiplicative Scatter Correction, Standard Normal Variate, and Normalization. Various statistical measures were used to evaluate the accuracy of the different machine learning and pre-processing combinations. Validation was performed on the remaining 25% samples of the dataset and the results were evaluated using a range of statistical methods, which include the mean error that measures the bias of the model, the root mean square error (RMSE) indicating overall model accuracy, the correlation coefficient (R2) showing the correlation between predicted and actual values, Lin’s concordance coefficient (rhoC) which is an adapted correlation coefficient used for model precision and accuracy, the ratio of prediction to deviation (RPD) that indicates predictive performance, and lastly the ratio of performance to interquartile distance (RPIQ) that measures predictive performance and model robustness. The best results were obtained by using a combination of Savitzky-Golay pre-processing paired with the Random Forest machine learning technique, with an RMSE of 6.9%, R2 of 0.62, bias of 0.75, rhoC of 0.75, and RPIQ of 1.8. Algorithms for DBD were created, where a combination of removed outliers, Savitzky-Golay with a Cubist model provided the best results with an RMSE of 0.16 g/cm3, an R2 of 0.72, a bias value of 0.01, a rhoC of 0.82, and an RPIQ of 2.31. Calibration algorithms for volumetric water content and DBD were also created for each catchment, where the results showed an overall further improvement over the regional algorithms that used all of the samples. The best catchment calibration algorithm for water content was the upper Olifants catchment’s water content, with a low mean error and RMSE of 0.59 and 5.07% respectively, accompanied by a high rhoC, RPD and RPIQ of 0.81, 1.85, and 1.94 respectively. The best catchment algorithm for DBD was the Sabie catchment with a 0 mean error and low RMSE of 0.08 g/cm3 a high rhoC, RPD, and RPIQ of 0.96, 3.52, and 3.75 respectively. Algorithms were then created for water retention at 33 kPa, 1500 kPa, and bulk density using the regional dataset to compare with the freely available international OSSL algorithms. The validation set of each created algorithm was uploaded to the OSSL prediction service to obtain predicted values, which were then compared to the created algorithms. Although the created algorithms were poorly predicted, they were still superior to the OSSL calibrations. The OSSL algorithm for the drained upper limit water retention indicate poor results of an RMSE of 17.12%, a mean error of 12.38, and very low RPD and RPIQ of 0.59 and 0.51 respectively. The created algorithm for the drained upper limit water retention performed better, with an RMSE of 8.89%, a mean error of 1.98, and an RPD and RPIQ of 1.13 and 0.99 respectively. The OSSL model for the lower limit water retention performed very poorly with an RMSE, mean error, RPD, and RPIQ of 20.85%, 19.24, 0.39, and 0.5 respectively. The created algorithm performed better with an RMSE, mean error, RPD, and RPIQ of 8.35%, 1.57, 0.97, and 1.24 respectively. The results that were found supported the idea that local calibrations are necessary for accurate and reliable predictions. The eventual compilation of sufficient local calibrations can lead to effective regional calibration algorithms, where sufficient regional algorithms can lead to the effective and accurate use of international algorithms like the OSSL algorithms.Master
The host status of selected soybean cultivars to Meloidogyne enterolobii under field and greenhouse conditions
Get PDFMaster of Science in Environmental Sciences
with Integrated Pest Management, North-West University, Vanderbijlpark CampusSoybean is a popular oilseed crop in South Africa with an increase in prodution and hectares that doubled in last 10 years. Crop production is predicted to increase with 41% by 2030. The crop is infected and damaged by a series of pests and diseases of which plant parasitic nematodes are among the most important pests. In South Africa, root-knot nematodes (RKN), Meloidogyne spp., are the most serious pests of soybean, and growers who have a RKN problem find it difficult to control the nematode and its damage. In the Mpumalanga region, soybean farmers suffer from serious yield losses due to infection of soybean by RKN. Among the different Meloidogyne spp., the more pathogenic Meloidogyne enterolobii, that is difficult to control, was previously found in maize and potato in the Mpumalanga region. The study's objectives are to identify the RKN species present at the field trial site using morphological and molecular techniques, to determine the host status of selected soybean genotypes commonly grown in the Highveld region of the Mpumalanga province to the RKN species occurring in a field site with a high natural infestation and verify the results in a glasshouse trial where inoculation with the RKN species took place. The soybean genotypes evaluated under field conditions, at intervals
of 30, 56 and 100 days after planting confirmed the results of the glass house studies terminated at 56 days after RKN inoculation. Yield of the genotypes at the field plot was also analyzed to determine whether some genotypes were tolerant to M. enterolobii. Results showed that genotype P61T38R and P48T48R were able to suppress the reproduction of RKN under greenhouse conditions significantly compared to the susceptible control while in the field trials, genotype P48T48R had a significantly lower infestation compared to the susceptible control. Genotype P59T33R showed tolerance as it produced a good yield even under high M. enterolobii population densities in the field site. Informing farmers about soybean genotypes that are poor hosts or tolerant to M. enterolobii and that can be cultivated to reduce its population densities, can be a great
shift in ensuring food security.Master
A framework for the implementation of an e-procurement system in local government: A case study of Harare City Council
Get PDFDoctor of Philosophy in Public Management and Governance, North-West University, Vanderbijlpark CampusPublic procurement remains one of the public administration functions often riddled with misgovernance and this has a detrimental effect on service delivery. This is true even though the 21st century has witnessed a significant growth of e-government tools which have the potential to revolutionise and transform governance. Egovernment tools like electronic procurement systems offer opportunities for improved procurement governance and efficient procurement outcomes, yet their implementation has remained slow, especially in the developing country context across all government levels. The implementation of an e-procurement system has also become a challenge at Harare City Council as the metropolitan continues to grapple with procurement misgovernance deriving from conventional methods of procurement. This is because e-procurement remains an underexplored initiative in the public sector, especially in developing countries. Evidence in the literature suggests that what contributes to this is the lack of knowledge on the key activities involved in e-procurement implementation since most organisations fail to interpret the initial adoption decision into implementation. The study utilised a qualitative research approach by adopting key informant interviews and document searches to aid an investigation of the implementation of an e-procurement system at Harare City Council. A sample of 30 participants was drawn to participate in key informant interviews and these included PRAZ, Ministry of ICT, Postal and Courier Services, Harare City Council, and Combined Harare Residents Association officials. Document search was used to investigate the implementation experiences of centralised and decentralised e-procurement systems from nine (9) different countries. Thematic and content means of data analysis were used to draw inferences from the data collected. Due to the council’s poor performance on the majority of the e-readiness indicators derived from the study, the study established low levels of e-procurement readiness at Harare City Council. The study concluded that low e-readiness levels derail the prospects of successful eprocurement implementation at the council. Additionally, the study established that certain unique characteristics of an organisation interact closely with critical eprocurement factors to influence e-procurement implementation outcomes. The study revealed that the challenges faced in implementing an e-procurement system at Harare City Council are closely tied to the implementation context and these included a lack of central government support, technology immaturity, and unreliable power supply among others. In consideration of the research findings, the study proposes a framework that serves as a guideline for the implementation of eprocurement
in local government.-North-West Universit
A framework to integrate indigenous knowledge into disaster risk reduction to build disaster resilience: insights from rural South Africa
Get PDFArticle, Faculty of Natural and Agricultural Sciences, Potchefstroom CampusPurpose – For millennia, indigenous or local knowledge (IK) has empowered rural communities particularly the most vulnerable and disadvantaged groups to prepare for, cope with and survive disasters instead of relying on external help only. However, this knowledge has been ignored by practitioners and policymakers in favour of Western science and technology-based methods of disaster risk reduction (DRR) and response. This paper proposes a framework for integrating IK into DRR because we believe the simultaneous use of IK and modern DRR measures could increase the resilience of rural communities.
Design/methodology/approach – The study finds solace in the pragmatism research philosophy which places emphasis on practical solutions and outcomes. The study followed a phenomenological approach of qualitative research with a total of 109 respondents participating in the study. The collected data were analysed thematically.
Findings – Participants in the study provided key insights into areas of interventions for improved integration of IK into DRR and these include, trust-building initiatives, recording and systematise traditional practices, developing localised, context-specific approaches to DRR planning and engaging traditional leaders, and increasing their participation in decision-making forums. We submit that the blending of modern and traditional techniques has the potential to create robust, adaptive systems for disaster preparedness, response and recovery, leading to safer and more resilient communities.
Originality/value – Pursuing an integrated approach to the use of IK and modern expert knowledge on DRR would be a step forward in addressing the fragmentation of the two knowledge systems
An experimental evaluation of drying banana slices using a novel indirect solar dryer under variable conditions
Get PDFArticle, Faculty of Natural and Agricultural Sciences, Mahikeng CampusNovel thermal characteristics of drying banana slices in an indirect dryer are presented for four different experimental drying conditions in the forced convection mode. The novel characteristics include measuring the airflow velocity in the drying chamber, measuring the thermal profiles in different trays comprehensively and measuring the relative humidity under different conditions. Two tests are carried for 16 h in two consecutive days (8 h per day for each test). The first test is on acloudy day followed by a sunny day, while the second test is carried out on two consecutive sunny days. Tests 3 and 4 are 24 h tests with high (0.23 m/s) and low (0.11 m/s) average drying chamber airflow velocities under good solar radiation conditions. The maximum temperatures obtained in the collector and the drying chamber are around 80 and 48 ◦C, respectively, for the 16 h tests. Significantly lower collector and drying chamber temperatures are obtained due to cloudy conditions. Maximum collector temperatures are around 84 and 95 ◦C for the high and low average airflow chamber velocities for the 24 h tests. The corresponding maximum temperatures in the drying chamber are around 50 ◦C for the 24 tests. The final moisture ratios are 0.26 (cloudy and sunny days) and 0.20 (two sunny days), respectively, for the 16 h tests. These final moisture ratios are lower than those obtained for the 24 h tests which are 0.32 and 0.28, respectively. Increasing the drying chamber airflow velocity results in faster moisture removal during sunshine hours for the 24 h tests. For tests 1, 2, 3 and 4, the maximum average collector efficiencies during the sunshine period are around 60, 80, 40 and 10 %, respectively. The average drying efficiencies for the total solar drying period for tests 1,2,3 and 4 on day 1 are 6.9, 6.9, 5.5 and 5.7 % respectively. These values are comparable, suggesting that the average collector powers, airflow velocities and efficiencies have a very small effect on the average solar drying efficiency for the whole drying period. The quality of the bananas slices mainly in terms of the colour and shape is also compared with previous studies and commercially available products. A reasonably acceptable quality product is obtained
Microstructure, mechanical and tribological properties of Al/Cu functionally graded material fabricated through powder metallurgy
Get PDFJournal Article, Faculty of Engineering (Chemical Engineering)) -- North-West University, Mahikeng CampusMechanical and tribological behavior of five layered Al/Cu functionally graded material (FGM) produced by powder metallurgy was presented in the study. Compressive strength and hardness was evaluated on Universal testing machine and Vickers hardness tester respectively. Tribological characteristics in terms of frictional coefficient and wear rate was examined on pin-on-disc tribometer under the influence of different normal loading, sliding velocity and sliding distance conditions. FGM showed varied hardness along the thickness direction and maximum hardness of 86 HV was found at graded region due to the formation of intermetallic compound (CuAl2). Compressive strength of FGM was 40.9% and 22.7% greater than pure Al and pure Cu samples. Al/Cu FGM exhibited superior friction and wear characteristics over base materials. To understand the failure mechanisms on fracture and worn out surfaces, they were observed under Scanning Electron Microscopy (SEM).Affordable and Clean Energ
Worst-Case Accident Analysis of Accident Tolerant Fuel in NuScale Using RELAP5/MOD3-Based Code
Get PDFJournal Article, Faculty of Engineering, Unit for Energy and Technology Systems-- Potchefstroom CampusResearch in nuclear engineering focusses on improving the safety of light water reactors (LWRs), driven by accidents like Fukushima in 2011. The severity of this accident was a result of active cooling system failures and cladding material oxidation resulting in hydrogen explosions. To this end, efforts concentrate on the improvement of passive safety in LWRs and the development of accident tolerant fuel (ATF). Natural circulation small modular reactors (SMRs) are new reactor concepts designed around passive safety. One such SMR called the NuScale SMR was chosen for this study. This study aimed to evaluate the combination of one selected passively safe reactor system with two selected ATF cladding materials, namely FeCrAl alloy and a silicon-carbide (SiC) composite, to determine if this combination would greatly increase the safety of LWRs. The use of ATF cladding materials in the NuScale for possible mitigation of a potential worst-case scenario accident has not been evaluated. A model of the SMR was developed using ASYST 3.4 thermal–hydraulics code and validated for steady state operation and one worst-case scenario accident transient using data taken from the NuScale final safety analysis report (FSAR) and literature. Results indicated minimal impact on steady state operation when employing ATF cladding materials. FeCrAl and SiC caused minor changes in peak cladding temperature (PCT) and peak fuel centerline temperature (PFCT). The worst-case scenario accident transient involved the inadvertent opening of one reactor vent valve (RVV) with subsequent failure of the emergency core cooling system (ECCS) and decay heat removal system (DHRS). In the current model, this led to failure of the Zr-alloy cladding after 6.42 h. This coping time was increased with the use of ATF cladding, with FeCrAl and SiC providing an increase of 0.5 and 4.35 h, respectively.Funding
This work is based on research supported through financial support by the Centre for Nuclear Safety and Security (CNSS), an initiative by the National Nuclear Regulator (NNR) of South Africa dedicated to developing skills demanded by the South African nuclear sector