Research Publications (Engineering and Built Environment)

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39th Johannesburg International Conference on “Chemical, Biological and Environmental Engineering” (JCBEE-23) Nov. 16-17, 2023 Johannesburg (South Africa)
(International Institute of Chemical, Biological & Environmental Engineering (IICBEE), 2023-11-16) Chetty, Manimagalay; Rathilal, Sudesh; Tetteh, Emmanuel; Singh, Nikita
Abstract—Recent energy demand and environmental concerns associated with fossil fuels makes algae biomass a desirable energy source. Algal biomass has a high organic content and a variety of metabolic properties that make it a promising resource for managing wastewater and sequestering CO₂, in addition to producing profitable biobased products. However, the operation and valorization of algae biomass on a large scale are accompanied by significant costs and setbacks. Therefore, the transition towards a biobased economy requires this study to examine emerging technologies that could utilize algae biomass as an industrialized feedstock from the wastewater settings. A comprehensive analysis of various green technologies of producing high-value products (lipids and hydrocarbons) from algae biomass was reviewed. The fundamental principles that limit the cultivation , extraction, and conversion of different types of algae biomasses for commercialization are discussed. Furthermore, the challenges, future research directions and potential opportunities of valorizing algae biomass was highlighted. It was noted that, exploring algae biomass towards sustainable waste management with resources recovery is viable for industrialization.
Academic training evaluation of building technology programme
(Department of Construction Economics and Management, University of Cape Town, 2022-08-01) Obaju, Biodun; Fagbenle, Olaposibo; Amusan, Lekan; Olaniran, Temitope
Training evaluation is one method through which tertiary institutions examine the effectiveness of the training they deliver in order to establish their students' readiness for the workplace. However, several higher institutions' evaluation methods have been confined to assessment in tests and exams without considering the knowledge and competencies acquired by students via training in fulfilling workplace expectations. Hence, the study assessed the training received by Building technology graduates in construction management and construction technology courses. The study adopted the Kirkpatrick model's first two stages of training evaluation (Reaction and Learning levels) with a questionnaire distributed to purposively selected Building technology graduates from two polytechnics in Southwestern Nigeria using a snowball sampling technique. Data obtained were analysed using descriptive statistical tools. The study's findings show that respondents were satisfied with the training acquired and possess the basic competency from the training. However, the graduates lack sufficient knowledge of laws and regulations governing construction work, the use of computer programme for planning and scheduling projects and the ability to use tools and equipment for construction work. The study findings imply that building graduates would be unable to work adequately in the construction industry without additional training, putting enormous strain on construction firms to re-training them to meet their expectations. Tertiary institutions need to revamp their training strategies and methods for students to improve their competency to strive in the construction industry.
Anaerobic treatment of slaugterhouse wastewater: evaluating operating conditions
(WIT Press, 2019-12-11) Chollom, Martha Noro; Rathilal, Sudesh; Swalaha, Feroz Mahomed; Bakare, Babatunde F.; Tetteh, Emmanuel K.
The aim of the study was to elucidate the effect of process parameters on the performance of an upflow anaerobic sludge blanket reactor (UASB) that was treating slaughterhouse wastewater. The UASB reactor was operated continuously under mesophilic conditions to evaluate its performance with respect to the removal of organics and, at the same time, monitor biogas production. Organic loading rate (OLR) was varied while keeping the hydraulic retention time (HRT) constant. Chemical oxygen demand (COD) removal efficiency higher than 75% was achieved at an OLR of 9 kg.COD.m-3.d-1, with a HRT of 12 h. Bulking sludge problems were not observed during the reactor operation period. Stability of the treatment process was achieved by the natural buffering of the system due to the produced alkalinity and also due to the characteristics of the wastewaters which was found to be rich in proteins and fatty acids.
Application of AI for frequency normalization of solar PV-thermal electrical power system
(IEEE, 2020-08) Estrice, Milton; Sharma, Gulshan; Akindeji, Kayode Timothy; Davidson, Innocent Ewaen
Grid-connected solar-PV schemes have become a significant part of the energy balance in the power system to satisfy the growing request for clean, affordable energy. This study attempts to link solar-PV generation with conventional thermal power plants and to integrate the control zone resulting in a hybrid solar PV-thermal electric power system using an AC tie line. An analysis of the frequency dynamics for varying load conditions of the interconnected system is studied. Diverse approaches of proportional, integral, and proportional-integral fuzzy logic built controllers are design and tested in order to match the electric power with variable loads of the system and hence to normalize the frequency ofthe system in shortest possible time. A comparative analysis of the design topologies is conducted out for the PV-Thermal scheme. Results obtain from the implementation are shown to justify the performance of proposed control efforts, using MATLAB software tool
Autonomous classification and spatial location of objects from stereoscopic image sequences for the visually impaired
(IEEE, 2022-07-20) Sivate, Themba M.; Pillay, Nelendran; Moorgas, Kevin; Singh, Navin
One of the main problems faced by visually impaired individuals is the inability or difficulty to identify objects. A visually impaired person usually wears glasses that help to enlarge or focus on nearby objects, and therefore heavily relies on physical touch to identify an object. There are challenges when walking on the road or navigating to a specific location since the vision is lost or reduced thereby increasing the risk of an accident. This paper proposes a simple portable machine vision system for assisting the visually impaired by providing auditory feedback of nearby objects in real-time. The proposed system consists of three main hardware components consisting of a single board computer, a wireless camera, and an earpiece module. YOLACT object detection library was used to detect objects from the captured image. The objects are converted to an audio signal using the Festival Speech Synthesis System. Experimental results show that the system is efficient and capable of providing audio feedback of detected objects to the visually impaired person in real-time.
Availability and operability in optical transport network architectures
(IEEE, 2020-08) Gomba, Masimba; Nleya, Bakhe; Chidzonga, Richard F.
A typical optical transport network interconnects multitudes of offices. With the advent of the Internet of Things (IoT) networking approach, it has become necessary for such transport structures to be flexible enough to accommodate heterogeneous communication services that generate escalating traffic loads every time. It is also key not only to accommodating continuously escalating traffic levels, but also to maintain a consistent Quality of Service, operability as well availability. This can only be achieved through the provisioning of effective and dynamic network control. In this paper, we explore the various operational issues such as incompatibilities in terms of physical layer transmission requirements and other control and management challenges emerging in present and future/ (envisaged) optical transport networks.
Balancing between demand and trading in microgrids
(IEEE, 2020-01) Gomba, Masimba; Chidzonga, Richard; Nleya, Bakhe; Khumalo, Philani
The envisaged future generation power or smart grid (SG) will incorporate ICT technologies as well as innovative ideas for advanced integrated and automated power systems. The bidirectional information and energy flows within the envisaged advanced SG together with other aiding devices and objects, promote a new vision to energy supply and demand response. Meanwhile, the gradual shift to the next generation fully fledged SGs will be preceded by individual isolated microgrids voluntarily collaborating in the managing of all the available energy resources within their control to optimally serve both demand and distribution. In so doing, innovative applications will emerge that will bring numerous benefits as well as challenges in the SG. This paper introduces a power management approach that is geared towards optimizing power distribution, trading, as well as storage among cooperative microgrids (MGs). The initial task is to formulate the problem as a convex optimization problem and ultimately decompose it into a formulation that jointly considers user utility as well as factors such as MG load variance and associated transmission costs. It is deduced from obtained analytical results that the formulated generic optimization algorithm characterizing both aggregated demand and response from the cooperative microgrids assist greatly in determining the required resources hence enabling operational cost viability of the entire system.
Comparative analysis of specific energy consumption and energy consumption benchmarking in galvanising plants
(IEOM Society International, 2022-08-04) Dewa, Mendon
The inadequacy of sustainable energy is endlessly posing major challenges globally. The issue of energy optimisation is indispensable for manufacturing sector, particularly for a hot-dip galvanising process where galvanising furnaces are the significant energy users. This study is aimed at comparative analysis of specific energy consumption and energy consumption benchmarking in four galvanising plants with the view to necessitate the identification of best practices. Energy baselines were used as quantitative reference points to compare energy performance indicators and quantify fluctuations in energy performance during the baseline and reporting periods. A quantitative analysis was also conducted to benchmark four galvanising facilities on factors that included the electricity/zinc ratio, electricity /dips ratio and product tonnage/zinc used ratio. The results revealed improved performance for plant 4 over time relative to the baseline consumption when compared to plants 1, 2 and 3. Plant 4 also outperformed other facilities after the energy efficiency interventions in terms of electricity/zinc ratio and electricity/ product tonnage ratio. Given the disparity between the results of specific energy consumption (SEC) for the four plants, it was concluded that SEC alone should not be used as an energy performance indicator.
Comparative study of binary classifiers for reducing false negative detection of melanoma in skin lesions
(IEEE, 2022-10-27) Jooravan, Amith; Reddy, Serendra; Pillay, Nelendran
Reliable and accurate classification of a skin lesion is essential to the early diagnosis of skin cancer, especially melanoma. Traditional classification methods require performing a biopsy on the lesion. The overlap of benign and malignant clinical features may lead to incorrect melanoma diagnosis and/or excising an excessive number of benign lesions. This paper focuses on the use of machine learning to aid physicians with the non-invasive classification methodology of skin lesions, whilst prioritising the minimization of false negative classification. The clinical features used are based on the ABCD rule, representing the asymmetry, border, colour and diameter of the lesion. The dermoscopic images chosen are of melanoma lesions less than 0,76mm in thickness which corresponds to the early stages of cancer. The investigated classification methods include K-Nearest neighbours (KNN), Naïve Bayes and linear support vector machine. (LSVM). This research proposes the use of a LSVM machine learning algorithm to classify a skin lesion as being either melanoma or non-melanoma with the lowest false negative rate of the investigated classification. Classification accuracy of 85% and a false negative rate of 5% is achieved.
Comparative study on the design methods for fly ash-flexible pavement
(University of Zagreb Faculty of Civil Engineering, 2021-05-20) Adedeji, Jacob Adedayo; Abejide, Samuel Olugbenga; Mostafa, Mohamed M. Hassan
Advancement in the design of pavement structures in the recent decade has brought about the use of finite element modelling (FEM) tools. Numerical simulation of flexible pavement through these models are yielding positive results and enhancing pavement design year after year. Various factors contribute to this success; yet, material characterization model in FEM is a major/critical factor. However, in using FEM, there are various material characterization input methods which are; input through laboratory testing; secondly, through correlation and lastly a backward calculation from deflection measurements. Overall, input methods are more realistic and give a better understanding of the mechanical behaviour of the material, nevertheless quite difficult to obtain. Although, the use of fly-ash stabilizer in pavement structure is not new yet its use has not been fully implemented in FEM design. As a result, a comparative study is considered based on input and correlation parameters on fly ash stabilized flexible pavement using Abaqus. Furthermore, the results show that the material input method provides better results and gives some amount of certainty on the design life of the pavement.
Cultural difference and IT project success : a fallacy or reality on the South African ICT sector
(Southern African Institute for Industrial Engineering, 2022-10-03) Javani, Blessing; Thabe, Mogolodi; Dewa, Mendon; Hattingh, Teresa
With high incidences of IT project failure in South Africa and globally. The paper aims to raise awareness of the impacts that cultural differences can have on IT project success, if not appropriately incorporated in project risk planning for practitioners and academics. Data was collected through semi-structured interviews on 15 IT project managers. The research demonstrates that most IT project managers do not regard cultural differences as a risk to project success, and do not regard the impacts that cultural differences of project stakeholders could have on a project as necessary for inclusion in project risk planning. The paper suggests that IT project managers and project team members should be culturally aware and sensitive and that one of the ways to address the impacts of cultural differences in IT projects is to promote trust, collectivism with a team identity in multicultural project settings thereby enhancing project success.
Curbing electricity theft using wireless technique with communication constraints
(IEEE, 2020-08) Tshikomba, Salome C.; Estrice, Milton; Ojo, Evans E.; Davidson, Innocent E.
Utility services are experiencing a common problem of power losses, which impose a significant impact on their annual budget. Practically, power losses consist of technical losses and non-technical losses. Technical losses are due to operations and aging of infrastructure, while nontechnical losses (NTL) are due to non-metered energy. The focus is on managing non-technical losses using an automation wireless method. The wireless ZigBee technique is proposed and further investigated for communication failure over long distances while solving the problem of stealing electricity. Advance-metering infrastructure (AMI) technique and smart meters are feasible for system integration; that is why they are chosen to be part of this study. The success of the study depends on quality data of the Utility, meaning the more accurate the data, the easier the analysis of outliers. The operation and planning of revenue protection contain a large amount of data that needs to be worked on, so data mining assists in that regard. Then the load profiling method assists in illustrating the variation in demandJelectricalload over a specific time. This is a preliminary investigation using a wireless communication technique as a viable solution in curbing electricity theft. The uniqueness of the proposed ZigBee system is that it recognizes the everyday act of stealing electricity through tempering with the meter box and tapping of the supply.
Degree accreditation report auto-generation by logic encoding and processing
(2021-11-10) Chetty, Manimagalay; Rawatlal, Randhir
Maintaining the accreditation profile of an academic programme is a key activity in so-called professional degrees such engineering, commerce and law. The complexity of the accrediting criteria tends to rise over time as accrediting bodies require quantitative evidence of competence of increasingly specific graduate attributes. Evaluation of graduate attributes may therefore require complex logic processing which challenges the human capacity. This has the negative side effect of discouraging curriculum revision not for pedagogic reasons but simply due to the complexity of evaluating complex logic patterns against a data set whose structure is shifting. These challenges can be overcome through the application of logic encoding and processing. A computing system is better suited to such processing tasks since logic processing is fundamental and well-established to such systems. On the other hand, the efficient representation of a complex accreditation logic rule base then becomes the challenge. This paper describes the representation of the accreditation logic of eight engineering academic programmes at the Durban University of Technology through the AutoScholar Advisor System in preparation for evaluation by the Engineering Council of South Africa. It is shown that the system generates accurate reports even with deeply nested logic structures and with changes in curriculum over time.
Design and implementation of a didactic cascade tank level control system
(IEEE, 2021-12-09) Pillay, N.
Engineering students in the field of industrial process control usually experience difficulty in assimilating theoretical concepts and its practical application. Typically, a laboratory practical based solely on computer driven software simulation offers the course facilitator a simple and cost effective solution to demonstrate control engineering fundamentals. The use of commercially available educational hardware kits may provide an improved learner experience but are relatively expensive. This paper describes the design and implementation of a low cost alternative to introduce realism into control education. The didactic system consists of dual cascaded tanks, continuous level sensors, a pump, a regulated power supply and an Arduino® MEGA2560 microcontroller connected to a computer. An automatic control system is designed in MAT LAB SIMULINK™ and deployed to the proposed hardware system to ensure that the tank level reaches a desired set-point. Experimental results indicate that the embedded control system is beneficial in demonstrating practical process modelling techniques and satisfies automatic controller design objectives in a laboratory environment.
Effective risk management practice and project success : the case of a water utility’s construction projects
(Southern African Institute for Industrial Engineering, 2022-10-03) Javani, Blessing; Mamena, H.G.; Dewa, Mendon
Failure to complete projects can significantly put an organisation’s competitive advantage, its strategic position, and competitive survival in jeopardy. The study sought to establish the effectiveness of applying project risk management tools and techniques at Rand Water, a state-owned entity. A quantitative approach with a survey research strategy was used in this study and 63 of the total population of 69 responded to the questionnaire that was issued. The Rand Water case study findings suggest that, in order to reduce project failure, one of the tools being utilized in managing projects is effective project risk management. In addition, the findings indicate that executive management must continue to apply project risk management tools and techniques coupled with regular project team training.
Effectiveness of dynamic voltage restorer in enhancing voltage profile in low voltage electric power distribution networks under normal mode operation
(IEEE, 2017-11) Taiwo, Ogunboyo Patrick; Tiako, Remy; Davidson, Innocent E.; Okafor, K.C.; Atimati, E.E.; Achumba, I.E.
© 2017 IEEE. This work addresses the compensation of power quality disturbance in electric power distribution network as a result of voltage variation and voltage unbalanced using one of the most effective power electronics based custom power controller known as Dynamic Voltage Restorer (DVR). DVR usually connected between the source voltage and the customer load. The new setup of DVR has been put forward using dqo controller and proportional integral (PI) controller method. The simulations are achieved using MATLAB/Simulink Sim Power System tool box. The simulation results attest to the effectiveness of the proposed DVR configuration in compensating the power quality problems in secondary distribution system. The simulation results runs are presented with different settings of parameter used in the model in order to help the validity of the function of DVR in enhancing the quality of power supply at customer side.
Efficient index modulation techniques for 5G and beyond
(IEEE, 2023-11-16) Mgobhozi, Bhekinkosi; Nleya, Bakhe
Index modulation (IM) techniques are emerging as promising approaches to improve spectral efficiency and reliability for 5G/future wireless networks. This paper pro vides an overview of key IM schemes including spatial modula tion, orthogonal frequency division multiplexing with index modulation (OFDM-IM), and enhanced variants like SIM OFDM. The spectral efficiency gains of these techniques are quantified mathematically. Spatial modulation uses antenna indices to convey additional information bits, while OFDM-IM utilizes subcarrier indices. SIM-OFDM further activates sub carriers selectively based on incoming bits. Experiments demonstrate spectral efficiency improvements over classical OFDM.
Energy demand and trading optimization in isolated microgrids
(IEEE, 2020-04-30) Chidzonga, Richard; Gomba, Masimba; Nleya, Bakhe
Future generation or smart grid (SG) will incorporate ICT technologies as well as innovative ideas for advanced integrated and automated power systems. The bidirectional information and energy flows within the envisaged advanced SG together with other aiding devices and objects, promote a new vision to energy supply and demand response. Meanwhile, the gradual shift to the next generation fully fledged SGs will be preceded by individual isolated microgrids voluntarily collaborating in the managing of all the available energy resources within their control to achieve optimality in both demand and distribution. In so doing, innovative applications will emerge that will bring numerous benefits as well as challenges in the SG. This paper introduces a power management approach that is geared towards optimizing power distribution, trading, as well as storage among cooperative microgrids (MGs). The initial task is to formulate the problem as a convex optimization problem and ultimately decompose it into a formulation that jointly considers user utility as well as factors such as MG load variance and associated transmission costs. It is deduced from obtained analytical results that the formulated generic optimization algorithm characterizing both overall demand and response by the cooperative microgrids assist greatly in determining the required resources hence leading to cost effectiveness of the entire system.
An energy efficient resource provisioning scheme for joint all photonic and wireless networks
(IEEE, 2022-08-04) Molefe, Mlungisi; Nleya, Bakhe
Flexible joint all photonic and wireless transport networks are a promising backbone network technological solution to accommodate the various dynamic bandwidth natured applications. In this paper, we mitigate methods aimed at maximizing available resources in a joint-photonic and wireless transport network in an energy-efficient manner. In so doing, we take into account challenges posed by transmission impairments as they tend to degrade signals and reduce their optical reach. We thus propose a state-of-the-art and innovative network architecture that can efficiently process a large amount of data. This architecture is designed to cater for bandwidth-hungry and bandwidth-dynamic applications and services. We further propose a load aware energy efficient resource optimization scheme using LERA algorithm, which couples with related service reconfiguration functions to maximize higher spectral efficiencies and minimal blocking in both optical and wireless sections of the composite network. Performance analysis shows that the proposed architectural scheme based on the LERA algorithm outperforms traditional benchmark techniques in achieving minimal blocking while efficiently maximizing spectral utilization compared to legacy benchmark approaches. Hence this scheme drastically enhances the utilization of the available resources and the overall network throughput.
Energy-aware lightpath routing algorithm for optical transport networks
(TELKOM, 2019-09-01) Gomba, Ndadzibaya Masimba; Nleya, Bakhe; Dewa, Mendon; Mutsvangwa, Andrew; Khumalo, Zephaniah Philani
Current as well as future applications and services are characterized by bandwidth intensiveness and as such are directly driving the need for the deployment as well as operation of backbone networks that optimize on bandwidth provisioning. Since infrastructural hardware equipment requirements are trebling every two years because of continued surging bandwidth demands, the telecommunication industry is also a growing direct contributor to worldwide greenhouse gases (GHG) emissions as well as energy consumption. This is driving necessities to research on more energy efficient networking approaches. A novel optimized energy-aware lightpath routing (OEA-LR) algorithm is herein proposed. It primarily takes into account the effects of physical layer impairments (PLI) since their effects in high capacity translucent optical networks may not be ignored when formulating routing and wavelength assignment (RWA) algorithms. We assume an all-optical network hence connection requests from source to destination are entirely provisioned in the optical domain, thus optical-electrical-optical (OEO) conversions are not utilised. Both analytical and simulation results indicate that the proposed algorithm improves both energy efficiency operation as well as resource utilization of the network. We further conclude on a general observation of reciprocations between energy savings and blocking performance.