Risk factors associated with early childhood caries: an epidemiological survey in Mariental, Namibia

Magister Scientiae Dentium - MSc(Dent)Early Childhood Caries (ECC) is a public health problem both in developing and developed countries. Its widespread prevalence among children makes it ideal for assessing the risk factors and identifying specific strategies that could be implemented to prevent the disease. The aim of the present study was to determine the risk factors associated with early childhood caries among 5 – 48 month children in Mariental, Namibia. The objectives were to determine (i) the prevalence and severity of early childhood caries in 5 – 48 months old children (ii) the risk of early childhood caries associated with feeding practices, social and cultural behaviour, sugar consumption, dental health awareness, fluoride and risk behaviour. The study design used was cross-sectional and descriptive. A convenience sample was used as mothers visited the post-natal clinic or the hospital for treatment of other ailments or problems. The sample size comprised 230 mothers and their children and only mothers and their biological children in the age range 5- 48 months were included in the survey. Data was collected by using an open- and closed-ended questionnaire that included questions regarding the child‘s dietary and nutritional habits, oral hygiene habits, socio-economic status and beliefs. Mothers and their biological children were examined for presence or absence of dental caries and the findings were recorded on a modified WHO data sheet. The mean age of the children was 24 months, the mean deft 1.5 and the Significant Caries Index (SiC) was 4.5. There was an increase in caries prevalence (add caries prevalence) with increasing age both among girls and boys. The mean DMFT of the mothers was 7.1, their SiC was 17.11 and more than three quarters had at least one tooth missing which was extracted due to caries and just under a quarter had one or more decayed teeth. Despite the fact that most of the mothers reported knowing the importance of good oral hygiene, brush their own teeth and cleaning their children‘s mouth both mothers and their children had high DMFT or deft indices. This is due to a multiplicity of factors – the majority of the mothers were both uneducated and unemployed and have difficulty in making or taking appropriate choices conducive to healthy lifestyles in turn affecting their behaviours and oral hygiene practices

Techno-economic performance comparison of crystalline and thin film PV panels under varying meteorological conditions : a high solar resource southern hemisphere case

Photovoltaic panel technologies have evolved considerably over a limited period. The most popular PV panel technologies can be divided into two main groups, the first being crystalline technologies and second, thin film technologies. This investigation compares the financial performance of three different photovoltaic (PV) panel technologies, namely, monocrystalline, polycrystalline and thin film copper indium gallium selenide (CIGS), based on measurements from a test facility and for varying meteorological conditions. The yield measurements of the panels from the site over a two-year period are used to develop the techno-economic indicator performance, for a proposed commercial installation. Measurements of solar irradiation and temperature are incorporated into a regression model for yield sensitivity analysis, which in turn is used to investigative the sensitivity of financial performance. It was seen that CIGS panels delivered on average 11.6% more yield when compared to monocrystalline technologies per kWp, with sustained outputs even during relatively colder periods. The improved financial performance of CIGS panels over monocrystalline panels was seen via a 24% increase in discounted return on investment, 7.8% reduction in payback period and 21% improvement in net present value. The regression model indicates that CIGS panel yields are less sensitive to lower solar irradiation and more sensitive towards higher temperatures. Overall variation of financial indicators for a range of yield outputs, is lowest for CIGS panels compared to both types of crystalline panels. CIGS panels show lower variability in financial returns particularly in conditions with higher temperatures that makes the results valid in geographical locations with higher temperatures and higher solar irradiation. The findings are useful for multiple stakeholders within the PV industry who have an interest in sub-Saharan Africa and the southern hemisphere, where such investigations are limited though solar resource is abundant.http://www.elsevier.com/locate/apenergy2022-06-24hj2021Electrical, Electronic and Computer EngineeringGraduate School of Technology Management (GSTM

Aggregation and internalisation of electricity externalities in South Africa

Energy-environmental impacts associated with non-renewable electricity generation have attained critical importance in South Africa. These impacts are quantified in order to obtain a monetary cost relative to local electricity prices. The methodology used to perform the analysis is the Impact Pathway Approach. Numerous energy-environmental external impacts have been evaluated in this study. The primary externality contributors were found to be GHG (green-house gas) emissions and public health effects from coal combustion. Other minor but important contributors to externalities are also identified and mentioned within the paper. Aggregated central externality costs were found to range from 5.86 to 35.36 SA c/kWh (1.31e7.95 US c/kWh), with central externalities estimates at 13.43 SA c/kWh (3.02 US c/ kWh). These central estimates were found to be 68.5% of average electricity prices during the year 2008. Conversion of externality costs from South African currency to US currency has been made with purchasing power parity exchange rates for the year 2008. This study provides sufficient methodological parity for countries with similar electricity generation backgrounds in Southern Africa and Africa as well as other developing countries, considering South Africa generates roughly 45% of the electricity on the African continent.South African National Energy Development Institute.http://www.elsevier.com/locate/energy2016-03-31hb201

A 20 year forecast of water usage in electricity generation for South Africa amidst water scarce conditions

Being a semi-arid country with limited fresh water resources and also a fossil fuel based energy intensive country, South Africa encounters the added pressure of allocating limited water resources. Roughly 90% of electricity in South Africa is generated from coal fired power plants that are located in semi-arid areas and use a combination of wet and dry cooling techniques. The paper aims to forecast water usage within coal based electricity generation in order to facilitate water management in water deficient parts of the country. Some of the older return to service (RTS) power plants which have been brought back to operation due to electricity shortages are water intensive and are located in water constrained water management areas. These power plants should be phased out gradually and replaced by higher efficiency dry cooled power plants - that are currently under construction - by the year 2020. Total water requirements could reach 370 gigalitres by the year 2021 from current levels of 360 gigalitres. Depending on the retirement of inefficient power plants, total water usage can be reduced by roughly 14%. Results show that management of water resources in the electricity generation sector can result in informed water allocations within water management areas. Proposed gradual retirement of the RTS fleet could result in a savings of 15% of the forecasted shortfall of 234 gigalitres by the year 2025. The deficit in electricity generation output caused by the retirement of the RTS fleet will have to be compensated by the simultaneous commissioning and operation of new build power plants. Such measures will provide much required water relief to water constrained water management areas. Overall increases in water usage until 2035 can be minimised if inefficient wet cooled power plants are gradually retired and if dry cooled power plants are more prominent.Water Research Commission (Pretoria, South Africa)http://www.elsevier.com/locate/rser2017-09-30hb2016Graduate School of Technology Management (GSTM

Enablers towards establishing and growing South Africa’s waste to electricity industry

In South Africa the electricity generation mix is relatively un-diverse whereas globally the transformation of the sector is advancing rapidly. Coal remains the predominant fuel source and limited success has to date been achieved in the renewable energy sector. The electricity generation sector is therefore hindered from moving towards an electricity generation landscape where alternative fuel sources is utilised. This research is aimed at gaining insight into the enablers that led towards an increasing trend (observed globally) in exploiting waste as a fuel for electricity generation, and to outline the presence of obstacles that hinder separation of waste for electricity use in the South African context. Furthermore it is an attempt at informing what appropriate interventions (operational and policy) may be considered suitable for South Africa to overcome these barriers in order to enable a sustainable South African waste to electricity (WTE) Industry. Findings show that numerous barriers to a WTE exists in the South African context, however overcoming these barriers is not as simple as adopting the European model with the aim to modify the electricity generation mix and waste management landscape. Selected enablers deemed appropriate in the South African context are adapted from the European model, and are greatly influenced by the prevailing socio-economic status of South Africa. Primary enablers identified were, (i) government support is needed especially in the form of subsidisation for green energy, (ii) increase landfill costs through the implementation of a landfill tax, (iii) streamline the process for Independent Private Power Producers (IPPPs) to connect to the national grid with off-take guaranteed and the inclusion of WTE into an electricity roadmap (effectively government’s strategy). The proposed enabling interventions would help in overcoming the barriers for a South African WTE industry.http://www.elsevier.com/ locate/wasman2018-10-30hj2017Graduate School of Technology Management (GSTM

Resilience is paramount for managing socio-technological systems during and post-Covid-19

The spread of the coronavirus concomitant with the Covid-19 disease highlights the interconnectedness between systems that serve humanity. These systems are typically portrayed in economic, ecology and environment, physical/technological, and socio-political contexts and maybe delineated in terms of the interconnectedness between these contexts. Any delineated socio-technological system represents an intriguing class of interconnected systems in the novel era of Society 5.0 concomitant with fourth industrial revolution. This article describes a framework and resiliency model for socio-technological systems plus an application of the lens of vulnerability and resilience to a case study energy systems enterprise. It is intriguing that the energy systems enterprise is usurping extant socio-economic robustness thereby undergoing an absorptive phase of resilience. The discourse complements existing body of literature on energy systems and society by emphasizing that the principles of vulnerability and resilience are paramount for sustainable management of socio-technological systems, and more so in a post-Covid-19 world.http://ieeexplore.ieee.org/xpl/RecentIssue.jsp/?punumber=46hj2021Graduate School of Technology Management (GSTM

Energy planning in sub-Saharan African telecom networks : decision support using a soft systems methodology

DATA AVAILABILITY STATEMENT : The data that support the findings of this study are available from the corresponding author upon reasonable request.This research paper narrates the application of the soft systems methodology (SSM) as a problem structuring tool, as well as the first step of a methodological approach that will provide decision support based on multi-criteria decision analysis in the planning of energy for telecom networks across sub-Saharan Africa. To ensure applicability of the methodology to a real-world issue, an international telecom tower company based in East Africa was selected as the case study. The SSM is utilized to characterize the decision problem context precisely, identify major stakeholder groups and their connections, and to discover each one's interests. This helps to achieve appropriate and holistic energy planning and management unlike the current trends which employ a reductionist approach. The outcome of the work leads to a model using SSM where stakeholder inputs can be captured, for the telecom company.Carnegie cooperation of New York through the Regional Universities Forum for Capacity Building (RUFORUM); Kyambogo University staff development funding, and the University of Pretoria's funded internal grants.https://wileyonlinelibrary.com/journal/syshj2023Graduate School of Technology Management (GSTM

Review of proposals for practical power sector restructuring and reforms in a dynamic electricity supply industry

South Africa’s electricity supply industry (ESI) remains a vertically-integrated monopoly despite global trends towards restructuring. The monopolistic nature of the ESI could hinder the development of distributed power systems as penetration of renewable electricity increases. The research aims to rationalise South Africa’s ESI evolution; propose practical power sector restructuring in the short-to-medium term; and to determine their potential impact. The research methodology included a single case study instrument, with embedded sub-units of analysis. Primary research data was gathered using semi-structured interviews with industry experts in addition to which secondary data from government documents and archival records were used for triangulation. Research results conclude that South Africa’s ESI grew due to techno-economic industrialisation factors, while Apartheid-era policies influenced the ESI in only some specific respects. The vertically-integrated status quo was sustained in the post-transformation period due to government’s focus on social imperatives; lack of regulatory & policy certainty; and conflicts in political ideology. South Africa didn’t experience the pre-conditions that triggered global power sector reforms in the late 20th century but these pre-conditions are now becoming evident. Privatisation of Eskom Generation and introduction of wholesale and retail competition are not practical in the short-to-medium term, proving the infeasibility of the standard model of reform locally. The introduction of an Independent System and Market Operator (ISMO) using a single-buyer model is seen as the most favourable and practical option, with the ISMO owning transmission infrastructure. The research suggests that ESI changes will increase system efficiencies, economic performance and private sector involvement, but will not reduce electricity tariffs. The scenarios, challenges and proposals identified in this research are also applicable to other countries in Africa and other developing regions of the world, that have similar social and political backgrounds, ensuring sustainable supply of electricity.http://www.elsevier.com/locate/rser2017-09-30hb2016Graduate School of Technology Management (GSTM

Estimation of occupational compensation based on a linear-quadratic methodology for the nuclear industry

Production of nuclear electricity is under scrutiny because of health issues connected with operation of nuclear facilities. National and international regulatory institutions aim to have regulations that ensure that any radiation dose received by the workers are kept as minimal as possible to reduce any risk on human health. Under these circumstances when a controlled nuclear facility is operating in standard conditions the possibility to have direct injuries connected by non-stochastic effects of ionizing radiation will happen only if regulations are violated. In addition, the stochastic effect of radiation may cause cancer. Nuclear power plants calculate the cost of potential health damage caused by ionizing radiation based on the Linear No-Threshold Relationship (LNT) between the dose and cancer risk. However, recent radiological research questions the validity of the LNT relationship for low and very low doses. In this paper, a new methodology based on a linear-quadratic function is proposed for the cost estimation of health risks induced by ionizing radiation, this new methodology results in significantly higher monetary cost for higher doses. At the same time the new methodology also results in lower monetary cost for low exposure levels and even zeros payment for environmental doses because they cannot be avoided. By adopting this new methodology it could provide motivation for nuclear facilities to improve health & safety measures.The Slovak Research and Development Agency under the contract No. APVV-15-0326 .http://www.elsevier.com/locate/ssci2019-06-30hj2018Graduate School of Technology Management (GSTM)Mechanical and Aeronautical Engineerin

A Control System Analysis for a Potential Geostationary Satellite for South Africa

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