In recent decades, ultrasound has been investigated for neural modulation due to its potential to provide high spatial resolution and low invasiveness. However, transcranial application of ultrasound remains a challenge due to the high acoustic impedance of the skull relative to the underlying neural tissue. This effect limits spatial resolution since high frequencies are attenuated and reflected within bone, allowing only low frequencies to effectively couple into neural tissue. To overcome these limitations, a thermoacoustic approach is considered in which RF is used to transmit signal past the skull and better couple high frequency ultrasound to the brain. Ultrasound signal could potentially be superimposed and steered within the brain through the use of a phased array of RF antennas placed outside the skull. To investigate this effect, this thesis presents the development of a 2D finite difference code that incorporates varying RF input parameters to simulate ultrasound initial pressure, velocity, and attenuation through layered phantom and human tissues. In particular, the simulator accounts for RF absorption and fluence within different materials due to varying antenna specifications, including peak power, pulse width, antenna gain, and aperture size. Results of various simulations are discussed, suggesting that increasing the number of antennas in the RF array allows for increased focusing and higher intensity of signal at a distance from the source than can be achieved by one antenna alone. Safety considerations are modeled to determine if adequate ultrasound intensity of 0.3-0.8 MPa can be provided through the thermoacoustic effect to modulate neural activity, while remaining below IEEE safety exposure guidelines of 20 mJ/cm2. Further investigation of more complex array configurations is required to determine if energy density can be spread over a large enough area to lower exposure risk, while providing clinically relevant pressures and frequencies for the purpose of neural modulation. Finally, the finite difference code is used to verify results from a preliminary thermoacoustic array design using omnidirectional antennas that was performed at MIT Lincoln Laboratory. It was found that antennas with larger gain will provide more efficient conversion of RF to ultrasound.

Urbanisation, associated with the construction of ‘hard' impermeable surfaces such as roofs and roads, results in increased stormwater runoff peak flows and volumes and their associated pollutants into downstream receiving waters compared with the pre-development state unless mitigated through Sustainable Drainage Systems (SuDS). Permeable Pavement Systems (PPS), one of the source control options in SuDS suite, are able to control stormwater runoff and reduce the discharge of pollutants (Armitage et al., 2013). Urban runoff typically includes sediment, trash, heavy metals, organic matter, hydrocarbons and nutrients. PPS are able to remove a sizeable proportion of these through sedimentation, filtration, adsorption and biodegradation. The most commonly used PPS in South Africa are Permeable Interlocking Concrete Pavements (PICP) which comprise concrete pavers laid on selected stone layer works with surface infiltration enabled by the presence of carefully designed openings between the pavers filled with fine stone. The treatment performance of PICP systems appear to depend on various factors such as: the layout of the pavers; the size and condition of the stone aggregates; the presence and location of any geotextiles; the type of outlet; and the time period between rain events. While some research on the treatment of stormwater by PICP has been published, not enough is known about the relative performance of different PICP designs. This dissertation describes an investigation on the performance of 10 different PICP systems constructed in the civil engineering laboratory at the University of Cape Town (UCT) for the treatment of various nutrients (ammonia-nitrogen, orthophosphate-phosphorus and nitrate-nitrogen) commonly found in stormwater runoff. Ten experimental cells each housing a different permeable pavement design were constructed in the NEB laboratory at the UCT. Infiltration tests (ASTM C1781) were first conducted to test the hydrological performance of each of the PICP cell. This was followed by ‘clean water' tests to establish the ‘base-line' pollutant values prior to the additional of any pollutants. Finally, typical Cape Town rainfall events were simulated using a synthetic stormwater mixture containing representative nutrients concentrations to test the treatment efficacy for each of the permeable pavement systems over the period of two years with intermittent dry and wet periods. The influent and effluent from all ten experimental cells were periodically collected and analyzed for pH, temperature, electrical conductivity and the effluent concentrations of ammonia-nitrogen, orthophosphate-phosphorus, nitrite-nitrogen and nitratenitrogen. It was found that there is a reduction of ammonia-nitrogen for all experimental cells ranged from 27.5% to 78.7% compared with the average of 63.7% removal rate from other studies. However, the reduction in the ammonia-nitrogen effluent concentrations may not be true removal as the ammonia-nitrogen may have been converted into nitrite-nitrogen or nitrate-nitrogen through the nitrification process. It was also found that: the cells with geotextiles had higher ammonia-nitrogen reduction than those cells without; the cells with washed aggregates had higher ammonia-nitrogen reduction than those cells with unwashed aggregates; and the cell with a raised outlet (creating a ‘sump' in the underlying stone aggregate) had the highest ammonia- nitrogen reduction of all. The orthophosphate-phosphorus effluent concentrations ranged from 37% orthophosphate-phosphorus addition to 11% orthophosphate-phosphorus reduction compared with the average of 47.7% removal rate of orthophosphate-phosphorusin other studies. The presence of geotextile resulted in higher orthophosphate-phosphorus removal efficiencies than those cells without; the cells with washed aggregates had higher orthophosphate-phosphorus removal efficiency than those cells with unwashed aggregates. The cell with an elevated outlet (sump) had the least orthophosphate-phosphorus removal efficiency. In addition, it was found that all the experimental cells added significant quantities of nitrates having nitrate-nitrogen addition ranging from 160% to 2580% which may be due to the nitrification process of ammonianitrogen (NH3) to nitrate-nitrogen (NO3 - ). The cell with the raised outlet had the highest nitratenitrogen addition which can be explained by its highest ammonia-nitrogen removal efficiency through the nitrification process. It was also found that the presence of geotextile has a negative impact on the nitrate-nitrogen removal efficiencies, possibly because geotextiles provide a habitat for the microbes that encourage nitrification. The nitrification process, promoting the reduction in ammonia-nitrogen effluent concentrations and the increase in nitrate-nitrogen effluent concentrations occurs when the pH is within the optimum range of 7.6-8.8 for growth of nitrifying bacteria, Lower pH results in higher nitrate-nitrogen concentrations. It was also found that the electrical conductivity – a measure of ionic strength – strongly depends on the length of the periods between rainfall ‘seasons'; it decreases rapidly during wet periods and increases during dry periods. A field testing was also carried out on the New Engineering Building (NEB) parking lot at the UCT to confirm the true treatment performance of PPS. The results show the PICP are efficiently removing TSS, ammonia-nitrogen and orthophosphate-phosphorus. The PICP with geotextile was found to have positive impact on TSS, ammonia-nitrogen and orthophosphatephosphorus removal than the one without. It was also found the presence of geotextile has negative impact on nitrate-nitrogen removal, with lower pH resulting in higher nitrate-nitrogen concentrations which aggress the previous laboratory findings.

No description available.

Several experimental and modelling studies have established that leak areas are mostly not fixed but vary linearly with pressure. Introducing this linear relationship into the orifice equation, results in a two-part modified orifice equation for leakage modelling with pressure head exponents of 0.5 and 1.5 respectively. Current hydraulic network solvers apply the conventional power leakage equation to model pressure dependent demands such as leakage. The empirically derived power leakage equation does not explicitly consider the leak area variation with pressure and it has been found to be flawed under certain conditions. The aim of this study therefore, was to incorporate the modified orifice equation into the algorithm of a hydraulic network solver and evaluate the impact this has on leakage modelling. Epanet is the hydraulic modelling software whose algorithm of the network solver was modified. In addition, a stochastic model for network leak generation and distribution was developed. The conventional and the modified software were applied to different levels of stochastically generated and distributed leakage in three differently sized pipe networks. It was found that the conventional power leakage equation results in significant leakage volume and flow rate errors under certain conditions. A methodology was also developed to correct the conventional power leakage equation so that it can be used to model leakage realistically without a change of the software to one that uses the modified orifice equation. The methodology was thereafter applied to an existing model that detects leaks in standard water distribution pipe networks, and the results showed significant improvements in the performance of the model.

The behaviour of sodium diethyl dithiophosphate (SEDTP) in flotation systems is of major interest to the Platinum Group Mineral (PGM) and Base Metal Sulphide (BMS) industry. Operationally, SEDTP has proved to be a point of contention as there are conflicting views regarding the role of collector with regard to its behaviour at the air-water and solid-water interface in the flotation process. The main objective of this thesis is to attempt to elucidate the surfactant behaviour of SEDTP and in particular its role at both the air-water and solidwater interface. To interpret its behaviour at the air-water interface, bubble pressure tensiometry was used to investigate the effect that SEDTP had on equilibrium surface tension. This was compared to the surface tension of a polypropylene glycol (PPG) frother, which was selected as a benchmark due to it being a surface active agent at the air-water interface and its general use in the industry as a frother. One of the most common collectors used in the PGM industry, sodium ethyl xanthate (SEX), was used as a benchmark collector, which is not known to affect the surface tension. Reagent concentrations were pushed high enough for the air-water surfactant, the frother, to reduce the surface tension (5-100 mM). The maximum concentrations of the three different reagents were tested at pH 7, 9 and 11. The pH was kept constant for other experiments at pH 9 and throughout the investigation the make-up water was deionized water (DIW). To investigate SEDTP’s behaviour at the air-water interface, a frothing column was used to determine its effect on foam stability. Reagent dosages used were similar to those used on plant operations, which are much lower than those used in surface tension experiments. Foam stability experiments were carried out at pH 9 using synthetic plant water (SPW) the constitution of which is shown in the thesis. Solids were subsequently introduced to investigate the effect that SEDTP had on froth stability (3-phase) and compare it to foam stability (2- phase). The solids used were samples from a PGM-containing silicate ore, milled to 60% passing 75 micron. As with the foam stability investigation, the froth stability experiments were carried out at pH 9. The pulp phase floatability of pyrite and galena with SEDTP was measured to investigate the effect that SEDTP had on particle hydrophobicity. Collector-less and pure reagent flotation recoveries were established to relate the effect that reagents had on the floatability. The microflotation of pyrite was carried out at pH 4 and pH 9 to investigate the effect of pH on the flotation of pyrite when using either SEDTP or SEX as single reagents and in the presence of a PPG frother. The effect of frother type and chain length in a mixture containing SEDTP was also investigated on pyrite at pH 4. Microflotation of galena was done at pH 4 to test the relative effect of SEDTP either as a single reagent or in conjunction with a frother compared to pyrite at the same conditions. Collector dosages for all microflotation experiments were determined so as achieve 50% of a single monolayer surface coverage on the mineral surface. This was done by determining the BET surface area of the mineral and using the known surface area footprint of a single collector molecule. Frother concentrations were similar to those used in previous studies. Furthermore, to minimize surface oxidation of the minerals, the samples were stored in nitrogen in a desiccator and acid-washed prior to the experiments. SPW was used to simulate a plant-like solution. Equilibrium surface tension results showed that the reagents used reduced the surface tension in the order: PPG frother, SEDTP, SEX. This is ascribed to the role of these reagents when adsorbing at the air-water interface. Foam stability tests were shown to be more sensitive than surface tension measurements in predicting the surface activity of SEDTP at much lower concentrations than the concentrations used for surface tension experiments. SEDTP did not have any significant effect on foam stability when used as a single reagent. However, when combined with a frother there was a significant improvement in the foam stability. SEX did not display any foam stabilizing effect with either a frother or in a collector mixture with a frother. This is consistent with the surface tension results, thus indicating that, compared to SEX, SEDTP has surface active properties, and more so when in the presence of a frother. The presence of solids in the froth stability experiments diminished the role of SEDTP at the air-water interface since no froth stabilizing effect was observed when it was combined with a frother compared to the two-phase foam system. This may be due to SEDTP partially adsorbing on the solid particles (as was shown by UV-Vis experiments) and thus not being available to affect the air-water interface. The collector mixture containing SEDTP and SEX decreased the froth stability. This may be attributed to increased particle hydrophobicity upon the addition of a collector, which could lend to the destabilization of the froth. Microflotation mineral recoveries are indicative of the bubble-particle attachment efficiency and hydrophobicity. At pH 9, no single reagents improved the recovery of pyrite. Combining SEDTP with a frother did, however, improve the recovery significantly. This was not observed for SEX as a single reagent or when combining SEX with a frother. However a 90 SEDTP: 10 SEX collector mixture containing frother exhibited further synergy by improving the total recovery and flotation rate of pyrite. At pH 4, single reagent flotation improved reagent-less flotation in all cases. The more acidic conditions would give rise to a more reducing environment which accommodates adsorption of surfactants at the solid-water interface. A 90 SEDTP: 10 SEX collector mixture showed synergy in terms of recovery, i.e. the combined effect was much greater than would have been expected from a weighted sum of each individual contribution. It has been proposed that this may be due to the heterogeneity of the surfaces, viz. the stronger collector adsorbing onto the coarser size fraction and weaker, possibly more selective collectors adsorbing onto a finer particle fraction. Once again, a mixture of SEDTP and a frother improved the flotation recovery synergistically, which is not observed when SEX is combined with a frother. Surfactant type, size and structure all contribute to the strength of the surfactant at the airwater interface. However, variable frother types (alcohols and PPG’s) at different molecular weights all displayed a similar synergistic effect with SEDTP. Furthermore, the mineral specificity of this synergistic phenomenon was tested on a second mineral, galena. The galena responded similarly to pyrite, in that an SEDTP-frother mixture significantly improved flotation rate and recovery above any single reagent. The findings in the thesis indicate that SEDTP plays a surfactant role as indicated by its ability to reduce surface tension and improve foam stability. However the presence of solids reduced this effect. In microflotation experiments, SEDTP displayed a synergistic effect when combined with a frother, therefore indicating that it also plays a collecting role by adsorbing at the solid-water interface. This synergistic effect between SEDTP and a frother can be explained by the ability of SEDTP, as well as the frothers, to adsorb at both the air-water interface and the solid-water interface. Furthermore, the presence of one of these surfactants at an interface improves the adsorption of the other in order to maintain electroneutrality. It is proposed that these observations provide supporting evidence for the classical Leja-Schulman penetration theory on the respective role of frothers and collectors in flotation. This theory proposes that during bubble-particle attachment, these interfaces come into contact with one another and condense to form a new mixed collector-frother monolayer at the bubble-particle film. The combination of surfactants that have bubble stabilizing ability and increase particle hydrophobicity at the bubble-particle interface will ultimately improve the flotation of the particles. However, it was shown in this dissertation, that this synergistic interaction is significant only in the case of SEDTP. SEX showed no evidence of this mechanism operating at all. This may be because all available xanthate molecules are adsorbed onto the solid surface and are unavailable to act at the airwater interface. In addition, it was shown that SEX is an extremely poor surfactant at the airwater interface. These findings have important ramifications for the current processing of PGMs and BMS where DTP is widely used.

The South African economy has in the past been categorised as carbon intensive due to an energy and capital intensive development path and an associated set of economic activities termed the minerals-energy complex. International export markets, specifically the European Union (EU), are systematically applying pressure on imported products with a high carbon footprint through potential trade barriers, border tariffs and consumer lobbying. The objective of this research is to determine whether South African pome fruit has a higher global warming potential (GWP) per kg fruit compared to pome fruit cultivated and packaged in other countries. Following on from this finding, is to determine whether the Greenhouse Gas (GHG) emissions for pome fruit in South Africa are declining, ,as could be expected based upon the declining carbon intensity of the South African economy since 1990 and efficiency improvements in the industry itself. The Attributional Life Cycle Assessment (ALCA) methodology is used to determine the Global Warming Potential (GWP) per kg fruit for multiple boundaries within the value chain, retrospectively for the years 2000, 2010 and prospectively for 2020. The product system boundary includes the farm, packhouse, controlled atmosphere store (CA) and cold store (CS). For the Life Cycle Inventory (LCI), the temporal variations in pome fruit cultivation, packing and storing for the export and local market are taken into account for each of the years studied. Using the single issue characterisation methods – the GHG Protocol and the IPCC GWP 2013 100a – the results for each of the years under study are compared at a value chain, boundary and activity level. The results indicate that the baseline GWP result for South African pome fruit in the year 2000 was relatively high compared to similar international LCA research on apples and pears during this period. However, the results for the years 2010 and 2020 clearly indicate a sustained decline in relative GHG emissions of South African pome fruit according to the GWP indicator result per kg fruit and the normalised results for the industry. It is clear that there has been an increase in eco-efficiency in a number of farming and agro-processing practices since 2000 which correlates to the declining CO2e emissions in the boundaries and value chain of South African pome fruit. The carbon intensity and efficiency of the pome fruit value chain is also determined for each year using the kg CO2e per kg fruit and the industry revenue for a specific year (ZAR 2010 adjusted for PPI). The findings support the hypothesis that the carbon intensity of the pome fruit industry has indeed declined since the year 2000. This decline in carbon intensity represents a relative decoupling of CO2e emissions from economic growth of the industry from 2000 to 2020.

Safety in a Nuclear Power Plant (NPP) is of utmost importance, as the implications of a nuclear event have dire consequences on people, animals, and the environment and on unborn generations. This dissertation is about Open Phase Conditions (OPCs), which occur when one or two of the three electrical phases are lost or open circuited, e.g. one circuit breaker phase doesn’t open or close. The study of this condition is important, as it can affect important-to-safety equipment, which is critical to the safe shutdown systems of the reactor in a nuclear power plant. The OPC can occur in the transmission (TX) switchyard or at the transformers connected to the nuclear plant. It also has the capability to make the offsite supply inoperable, which is the alternate source of power for the nuclear safety systems. As many as sixteen (16) cases of Open Phase events have occurred in different countries worldwide from 1994 till 2015. An event also occurred in the Koeberg Nuclear Power Station (KNPS) in South Africa on the 11th November 2005. When these events occurred, the protection schemes did not “see” nor isolate the condition, as this was discovered to be a design vulnerability. This was due to oversight in the design of the protection to detect this condition. This dissertation seeks to answer the following research question: Is it possible to prevent or mitigate an open phase condition from occurring in the switchyard of a nuclear power plant? Previous work has attempted to address the lack of awareness of people working in close proximity to a Nuclear power station i.e. amongst staff working in the switchyard and operators in a nuclear plant, by sharing the operating experience (OE) of OPC occurrences. The approach to answer the research question lies in the analysis of the awareness of the people involved, as the condition cannot be prevented if it is not known. Case studies of the documented OE were categorised and analysed using a simplified root cause analysis method. A survey was conducted to assess the OPC awareness and perceptions of people in the system operator, i.e. TX division and at the Koeberg nuclear power station, within the Eskom Holdings utility. The results demonstrate that there is insufficient overall knowledge and understanding of this condition within the system operator. Operators in the nuclear plants all over the world have been required by the US Nuclear regulator, to be trained and to be aware of this condition. The results of this dissertation highlight the focus areas in people’s awareness that need attention. And that educating the system operator through training will strengthen the relationship between transmission and the nuclear plant within Eskom holdings.

Digital innovation from the Internet of Things (IoT), Artificial Intelligence, Tactile Internet and Industry 4.0 applications is transforming the way we work, commute, shop and play. Current deployment strategies of these applications emphasize mandatory cloud connectivity. However, this is not feasible in many real-world situations particularly where data dense and mission critical applications with stringent requirements are concerned. Cloud computing offers unlimited on-demand computing, storage and networking power for industry to leverage. However, as its scope and scale continues to expand, its limitations like high latency, accessibility, security and compliance shortcomings prevent its greater use and applicability particularly in scenarios where real-time communication and the quality of rapid computing delivered is a necessity. Fog computing hopes to bridge this gap by introducing an intermediary computing layer between end users and the cloud. At present, architectures for fog computing exist in specialized areas with current implementations being proprietary, vendor-locked and requiring dramatic and non-transferable changes to hardware and software to meet vendor requirements. Moreover, fog computing is still quite a recent area which makes the state of the art incipient regarding architecture definitions, middleware and real-world implementations. There is therefore an urgent need for standardization of these technologies. This is of paramount importance as otherwise, there will exist multiple and not necessarily compatible solutions which could lead to a fragmented marketplace that would fail to grow. In an effort to address these limitations in current fog architectures, this dissertation proposes and implements a novel fog computing architecture that aligns the reference architectures from a leading industry consortium, OpenFog, and a leading standards setting organization, the European Telecommunications Standards Institute (ETSI). This cooperation framework from industry, academia and regulatory institute aims to make it easier for both application developers and infrastructure solution providers to develop towards a common, open and interoperable fog computing environment. The proposed framework has the following attributes: modular, plug-in design, generic, open, standards compliant, vendor agnostic and runs on high volume standard hardware whilst preserving the benefits offered by public clouds such as containerization, virtualization, orchestration, manageability and efficiency. Moreover, for the various stakeholders in the fog value chain where it is key to strike a balance between information technology and business operations, this thesis tenders insights and best practices to help achieve these multiple and sometimes competing goals. The proposed framework was implemented in a testbed environment made up entirely of free and open source software, therefore creating a convenient point of departure for further research by others. Two geographically distributed fog node data centres and a cloud management and orchestration tool were setup in the testbed. While this evaluation framework and practical implementation demonstrated proof of concept, further evaluations were conducted to benchmark the performance against existing alternative solutions. These evaluations were based on a prototype industrial IoT application that was deployed on the testbed to evaluate the impact of the Open Vendor Agnostic Fog Framework (OVAFF) solution on application performance. The implementation showed that the proposed OVAFF solution is feasible, implementable and supports distributed edge cloud data centres. Results from the prototype application showed that OVAFF can extremely provide up to tenfold throughput and ultra-low latency, jitter and packet loss rate better than the remote clouds. Moreover, there is more superiority exhibited by the OVAFF for other non-performance based attributes like data reduction, compliance and geographical locality of control. In addition, the results also pointed towards the viability of open business models like federated infrastructure sharing and a fog market place in the fog ecosystem. Finally, this thesis tackled the highlighted open challenges in current fog systems such as orchestration, distribution, tiering, heterogeneity and resilience; which were outlined in the research motivation and problem definition.

Remote sensing provides accurate and timely data for earth’s change detections for better decision making. Both land use and land covers (LULC) are important dynamics in understanding the dynamics interaction between human activities and the environment and the changes within the environment due to these interactions. Rapid population growth together with an irreversible process of urbanisation results in productive agricultural land which serves as the main source of livelihood under pressure for residential purposes. The reason being rapid urbanisation led to rapid increase of informal settlement in the developing countries and hence information about location and the extent of these informal settlements is needed to guide resources allocation distribution for upgrading and decision making processes. Thus a quantitative measure like the spatial metrics is used in this research to provide information on the rate and pattern of urban expansion for urban planners to device a mechanism for proper spatial planning and provide a management policy direction for solving complex problem of population growth and the encroachment of the informal settlements into fertile agricultural land along the urban peripheries emanating from internal and international migrations. The study indicates that there has been an increase of 928 Ha in the built up land between 2005 and 2016, while at the same time the agricultural has decreased by 820 Ha at the expense of the built up land. This indicates that in 11 years, percentage decrease of 0.35% in agricultural land is lost for built up land annually. In the similar manner, around the urban peripheries there is a loss of 3.4% of agricultural land (60.36 Ha) annually for informal settlement between 2005 and 2016 The spatial metrics which provide the quantitative description of composition and configuration of landscape shows that the urban peripheries are gradually being transformed from being simple compact to being more fragmented and complex as indicated by Area Weighted Mean Patch Fractal Dimension (AWMPFD) greater than one. This study indicates a need for immediate intervention through planned settlement to cater for an ever increasing population growth from natural birth and different types of migrations.

Leakage detection and management have been proposed as effective ways of mitigating and managing water losses in an age where water scarcity has become prevalent. To this end, several methods have been developed and suggested with different benefits and drawbacks The presently available leakage detection methods, however, fail to identify and characterise the leakage while simultaneously assessing the condition of the water distribution network (WDN). This function is imperative for understanding and addressing leakage. WDN assessments are also important as knowledge of the network parameters helps in reducing water losses through planned infrastructure maintenance programmes. A pipe condition assessment device (PCAD) was thus developed which can detect, characterise leakage and assess the condition of the WDN. However, the efficacy and reliability of this device had not yet been established. In this study, the device was used to characterise leakage and assess system conditions in water networks. Initially, laboratory tests on six known leak types were conducted on a standardised laboratory setup. The leakage characteristics of these pipes were found through regression analysis. The results from the tests established that to 95% level of confidence; the standardised setup can produce repeatable and comparable results to previous studies. The accuracy of the PCAD instrumentation was verified and the device calibrated, the same pipes were then tested on the standardised setup using the PCAD. An overlap of the results from the laboratory experiments and the PCAD revealed that to 95% level of confidence, the device could adequately characterise leakage in pipes. A low variance of less than 4% of the mean parameter, across all tests conducted using the PCAD, informed that the results obtained through using the PCAD are repeatable and reliable. Field tests in the Kensington DMA were done and revealed the limitations of the device, such as its inability to characterise leakage in pipe sections that cannot be successfully isolated. However, in pipelines that were successfully isolated, the PCAD was able to detect and identify leakage characteristics in water networks and aid in conducting maintenance runs. Consequently, this study contributed to the body of knowledge by statistically establishing that the PCAD could adequately, and reliability characterise leakage in real water distribution networks.