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Wave energy is an important renewable energy source. Previous studies of wave energy conversion (WEC) have focused on the maximum power take-off (PTO) techniques of a single machine. However, there is a lack of research on the energy and power quality of wave farm systems. Owing to the pulsating nature of ocean waves and popular PTO devices, the generated electrical power suffers from severe fluctuations. Existing solutions require extra energy storage and overrated power converters for wave power integration. In this study, we developed a master-slave wave farm system with rotor inertia energy storage; this system delivers self-smoothed power output to the grid and reduces the number of converters. Two control methods based on the moving average filter (MAF) and energy filter (EF) are proposed to smooth the output power of wave farms. RTDS simulations show that the proposed systems and control methods facilitate simple and smooth grid integration of wave energy. Keywords: Wave farm, Energy storage, Power smoothing, Power quality, Energy quality

PhD (Business Administration), North-West University, Potchefstroom Campus, 2019 Small and Medium Enterprises (SMEs) are increasingly becoming the productive drivers of economic growth and development in South Africa. This is so because SME sector is the engine of employment creation and the key contributor to the GDP of the country. Despite their contribution to the development of the economy, the rate of failure and discontinuity of SMEs in South Africa is still one of the highest in the world. A lot of business scholars have addressed the issue plaguing the sector by identifying the causes of SME failure but have not provided a solution on what needs to be done for these business ventures to become sustainable. The purpose of this study therefore was to develop a framework for enhancing the sustainability of SMEs in municipalities of the North West province of South Africa. A number of objectives were set to accomplish the purpose of the study that built up to the development of the proposed framework to enhance the sustainability of SMEs in this region. In order to attain the objectives of this study, the study used five principal theories that address the sustainability of SMEs: the financial gap theory, the resource dependence theory, the theory of mergers and acquisitions, investment theory and trickle-down theory. The pragmatist research paradigm underpinned supported the adoption of a sequential explanatory mixed method approach for collecting and analysing quantitative data in a first phase, while the qualitative phase was built on the outcomes of the preliminary quantitative results. The target population of this study was drawn from the current number of formal (duly registered) SMEs in the North-West province as indicated by the Central Supply Database of the Provincial Department of Finance. This population was chosen from the four district municipalities of the North-West province of South Africa and a non-probability sampling method was used to select a sample size of 400 small business owners and managers for the quantitative phase and 20 for the qualitative phase. The Statistical Package for Social Science was used to analyse quantitative data and Atlas-Ti software was used to analyse qualitative data. The findings of the study indicate that the major causes of SME failure and discontinuity in the North West province is due to various factors such as lack of strategic business planning, lack of sufficient finance, poor management, lack of innovation, lack of business research and low level of human capital education and training. Therefore, it is imperative for SME owners and managers to formulate and pursue a strategic business plan for their businesses, seek for measures to foster an improved flow of finances and implement strategic management in their businesses. More so, it is necessary for SME owners and managers to be innovative in business, conduct business research and upgrade the level of education and training of their human capital to ensure successful and sustainable business enterprises. More importantly, because of their contribution to economic growth of the country, the government should endeavour to support and encourage this sector to develop by offering financial and technical assistance to small business enterprises through relevant departments and agencies. Doctoral

Oligotrophic catchments with short spatey streams, upland lakes and peaty soils characterise northwest European Atlantic coastal regions. These catchments are important biodiversity refuges, particularly for sensitive diadromous fish populations but are subject to changes in land use and land management practices associated with afforestation, agriculture and rural development. Quantification of the degree of catchment degradation resulting from such anthropogenic impacts is often limited by a lack of long-term baseline data in what are generally relatively isolated, poorly studied catchments. This research uses a combination of palaeolimnological (radiometrically-dated variations in sedimentary geochemical elements, pollen, diatoms and remains of cladocera), census, and instrumental data, along with hindcast estimates to quantify environmental changes and their aquatic impacts since the late 19th century. The most likely drivers of any change are also identified. Results confirm an aquatic biotic response (phyto- and zooplankton) to soil erosion and nutrient enrichment associated with the onset of commercial conifer afforestation, effects that were subsequently enhanced as a result of increased overgrazing in the catchment and, possibly, climate warming. The implications for the health of aquatic resources in the catchment are discussed Environmental Protection Agency in Ireland (ILLUMINATE 2005-W-MS-40, P.McGinnity was supported by the Beaufort Marine Research Award in Fish Population Genetics funded by the Irish Government under the Sea Change Programme.

Given the highly climate-sensitive character of agricultural production, climate change has obvious and important ramifications for agricultural commercialisation, which in turn has a bearing on poverty, gender empowerment, and food and nutrition security. The nature and extent of climate change implications for agricultural commercialisation will depend on: the magnitude of the climate impacts that farmers have to deal with; and, the extent to which sustainable intensification processes can be pursued in ways which strengthen, rather than weaken, adaptive capacity and resilience in the face of climate change. This brief provides a summary of a longer working paper, which offers a review of recent literature on the implications of climate change for agricultural commercialisation and APRA’s research in this area.

This Article examines the genesis and context of SE4All, placing the effort within both itshistorical and international policy contexts. It highlights the voluntary nature of the initiative andargues that its effective implementation and the achievement of its goals require the articulation ofan applicable international legal framework that aids the transformation of SE4All’s policy actionsinto binding international legal commitments. The article contends that such a transformation doesnot depend on the creation of entirely new legal rules or institutions. Instead, an effective frame-work for successful implementation of SE4All can be derived from existing rules of internationalhuman rights law and sustainable development law. Reliance on these twin bodies of interna-tional law will increase the prospects for SE4All to achieve energy access and related goals thatits predecessor initiatives have failed to accomplish

Thesis (MEng)--Stellenbosch University, 2018. ; ENGLISH ABSTRACT: The development of a prototype variable valve duration reciprocating steam expander was undertaken. A variable valve duration system was developed which could vary the cut-off ratio from 15 % to 90 %. An existing internal combustion engine was converted into the prototype reciprocating steam engine. Thermodynamic models were developed to determine the theoretical power output and working fluid consumption of the manufactured prototype engine. Proof of concept tests were performed on the engine. The engine was operated at 500 rpm where the output power and air consumption were measured. Tests were performed for various cut-off ratios to determine the influence on output power and air consumption. The experimental results showed a strong correlation to the theoretical effect of cut-off ratio on power output and air consumption. The maximum experimental output achieved was 1.396 kW at an 80 % cut-off ratio. The experimental power output was lower than the theoretical results which neglected mechanical losses in the system. The thermodynamic model over predicted the air consumption due to the assumption of instantaneous valve events. ; AFRIKAANSE OPSOMMING: Die ontwikkeling van 'n prototipe veranderlike klep duur wederkerige stoom uitsitter is onderneem. 'n Veranderlike klep-duurstelsel is ontwikkel wat die afsnyverhouding van 15% tot 90% kan wissel. 'n Bestaande verbrandingsmotor was omskep as die bewys van konsep wederkerige stoom-enjin. Termodinamiese modelle was ontwikkel om die teoretiese kraguitset en werkvloeistofverbruik van die vervaardigde prototipe-enjin te bepaal. Bewys van konseptoetse is op die enjin uitgevoer. Die enjin is teen 500 rpm bedryf en die uitlaatkrag en lugverbruik was gemeet. Toetse is uitgevoer vir verskillende afsnyverhoudings om die invloed op die uitsetkrag en lugverbruik te bepaal. Die eksperimentele resultate het 'n sterk verband getoon met die teoretiese effek van afsnyverhouding op kraguitset en lugverbruik. Die ...

Devon County Council

Spider webs must be able to absorb the energy of impacting insects, and similarly, rock support must absorb the energy of ejected rock in rockbursts. A consideration of the properties of spider webs shows that spider silks (threads) are extremely strong, typically three times as strong as common steel. Spiders also construct their webs with yielding mechanisms to enhance their energy-absorbing capability. In this paper, the techniques employed in web construction are compared with those used in rock support in excavations prone to rockbursting. It is shown that the design of rockburst support could benefit from some of the capabilities used by spiders in the construction of their webs.

The phenomenon of ���climate change litigation��� has come to the fore in recent years as campaigners and activists have become increasingly frustrated at a perceived lack of action on the part of the international community and individual states in terms of getting to grips with the climate change problem. Existing legal mechanisms available to private parties and other bodies, such as non-governmental organizations (NGOs) have been used as a means of endeavouring to hold governments and polluters to account for the effects of climate change. The physical impact of climate change on life and property has been thrown into sharp relief by floods and wildfires in all parts of the globe. One aspect of climate change litigation focuses on the role that tort might play in attempting to secure compensation for at least part of such losses. No one would pretend that actions of this nature can actually solve the problem, but they may serve to shame polluters and so forth by establishing an actual link between their activities and the tangible consequences of climate change. However, such actions raise formidable causation difficulties which have, until recently, rendered such claims outlandish and highly speculative. Nevertheless, developments in extreme weather event attribution may be about to reduce the conceptual and theoretical barriers to bringing such claims. In this article it is argued that, from a UK perspective, existing causality tests may be capable of accommodating such evidence, although, one must be aware of countervailing policy considerations which may inhibit the courts from adopting such an approach. Keywords: Climate change, climate change litigation, attribution science, tort, causation ALJ 2021, 268���284

Master of Commerce in Management Accountancy, North-West University, Vanderbijlpark Campus Access to electricity is one of the key drivers of economic activity, and sustaining a reliable electricity supply is essential for South Africa to grow its economy, reduce the unemployment rate, and alleviate poverty. Since 2007, the country has grappled with electricity shortages, resulting in continuous power cuts in the form of load shedding. This predicament is mainly attributed to an aging power generation fleet, with much of the infrastructure reaching the end of its operational lifespan. The aging fleet’s reliance on coal, a non-renewable fossil fuel, contributes to excessive emissions of greenhouse gases (GHG) into the atmosphere. These emissions cause environmental challenges such as global warming, manifesting in increased temperatures, intensified storm events, and rising sea levels. To address the electricity challenges without harming the environment, South Africa is transitioning from fossil fuel power generation technologies to Renewable Energy Technologies (RET) such as Concentrated Solar Power (CSP) technology. The research question driving this study was whether CSP could be economically viable as a renewable energy (RE) source in South Africa. Thus, the primary objective was to evaluate the economic viability of CSP as an RE source using a cost-benefit analysis. The study further applied a PESTLE analysis and a SWOT analysis to evaluate the economic viability of CSP as an RE source. The research followed a qualitative methodology. Data were collected through semi-structured interviews with eight participants who were selected using purposive sampling. The sampling was performed based on the individuals’ knowledge of CSP plants from a strategic and operational point of view. The sample comprised two CEOs, two CFOs, two plant managers and two operations managers from two CSP plants in the Northern Cape Province, South Africa. The findings from the literature review and empirical study indicate that CSP systems equipped with thermal energy storage (TES) not only generate electricity during sunlight hours, but can continue to generate electricity after sunset. This capability stems from TES’s ability to store energy or heat acquired during the day, allowing the technology to use the stored heat after sunset for sustained electricity generating. The ability to generate electricity after sunset enables CSP technology to provide baseload power to the grid as requested by grid operators. In contrast, other RETs, such as wind and photovoltaic (PV), can only generate electricity when there is adequate wind and sunlight respectively, leading to grid instability. The results from the cost-benefit analysis, the PESTLE analysis and the SWOT analysis showed that, for the South African context, CSP technology is indeed economically viable as an RE source. The study recommends that the South African government maintain its support for CSP technology and consider increasing the allocated electricity generation capacity by CSP beyond the 600 MWh currently designated in the Integrated Resource Plan. It is advised that the country’s infrastructure be upgraded to accommodate further CSP developments in the Northern Cape. These recommendations are based on the fact that the Northern Cape has some of the world’s highest levels of direct normal irradiance, which is crucial for the optimal functioning of CSP technologies. Masters