Research Publications (Engineering and Built Environment)
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Item 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, NikitaAbstract—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.Item 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, TemitopeTraining 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.Item Acetic acid adsorption onto activated carbon derived from pods of Acacia nilotica var astringens (Sunt tree) by chemical activation with ZnCl2(IISTE, 2015) Elhussien, Mutasim H.; Isa, Yusuf MakarfiThe purpose of this study is to prepare and investigate the adsorption behavior of acetic acid onto two samples of activated carbon prepared from Acacia nilotica var astringens, Sunt tree,( SUNT-C1 and SUNT-C2). Applicability Langmuir, Freundlich, Temkin and Dubinin-Radushkevitch models of adsorptions isotherm have been tested, while acetic acid initial concentration varied between (0.010 – 0.300) mol/dm3. A comparative study of adsorption capacities of these samples was performed. The obtained data were compared and fitted well with the four models; there exist a correlation between physico- chemical properties of the activated carbons and the sorption processes. The maximum monolayer coverage (Qo) from Langmuir isotherm model was determined to be 1.016mg/g. Also from Freundlich Isotherm model, the sorption intensity (n) which indicates favourable sorption and the correlation value are 1.11 and 1.09 respectively.Item Adapt or Die! Building Information Modelling (BIM)(Association of Schools of Construction of Southern Africa, 2016) Haupt, Theo C.; Hefer, ElkePurpose: The emergence of Building Information Modelling (BIM) demands that quantity surveyors review their roles in the construction sector. This study examines the responsiveness of the quantity surveying discipline to BIM. Design/methodology/approach: A sample of quantity surveyors in Durban will be surveyed using an instrument developed from published literature on responses of quantity surveying to BIM. Research limitations: The sample of quantity surveyors was drawn from the Durban area using the Association of South African Quantity Surveyors (ASAQS) and South African Council for the Quantity Surveying Professions (SACQSP) database. Findings: Preliminary findings suggest that quantity surveyors’ knowledge about BIM, software and innovation was at best rather average. They recognized the most obvious benefits of embracing BIM such as the time taken to produce Bills of Quantities and accurate cost estimation. Largely because of their lack of knowledge of available technologies they could not comment assertively on many of the issues surrounding the relationship between BIM and quantity surveying. This further resonates with the uncertainty that exists surrounding BIM and its business value and return on investment. They disagreed that technological advancements presented threats to their existence or the services that they traditionally offered. In the main the findings of the study resonated with those of other studies done particular in developing countries. Response to conference theme: This study identifies the reasons why BIM is not being readily embraced by quantity surveyors more pervasively. Practical implications: The findings provide the opportunity to improve the services currently offered by quantity surveyors but also new and innovative services driven by BIMItem An adaptive neuro-fuzzy inference scheme for defect detection and classification of solar Pv cells(Academy Publishing Center, 2024-09-12) Moyo, Ranganai Tawanda; Dewa, Mendon; Romero, Héctor Felipe Mateo; Gómez, Victor Alonso; Aragonés, Jose Ignacio Morales; Hernández-Callejo, LuisThis research paper presents an innovative approach for defect detection and classification of solar photovoltaic (PV) cells using the adaptive neuro-fuzzy inference system (ANFIS) technique. As solar energy continues to be a vital component of the global renewable energy mix, ensuring the reliability and efficiency of PV systems is paramount. Detecting and classifying defects in PV cells are crucial steps toward ensuring optimal performance and longevity of solar panels. Traditional defect detection and classification methods often face challenges in providing precise and adaptable solutions to this complex problem. In this study the researchers pose an ANFIS-based scheme that combines the strengths of neural networks and fuzzy logic to accurately identify and classify various types of defects in solar PV cells. The adaptive learning mechanism of ANFIS enables the model to continuously adapt to changes in operating conditions ensuring robust and reliable defect detection capabilities. The ANFIS model was developed and implemented using MATLAB and a high predicting accuracy was achieved.Item Advanced distributed cooperative secondary control of Islanded DC Microgrids(MDPI AG, 2022-05-28) Aluko, Anuoluwapo; Buraimoh, Elutunji; Oni, Oluwafemi Emmanuel; Davidson, Innocent EweanIn an islanded DC microgrid with multiple distributed generators (DGs), the droop control is employed to realize proportional current sharing among the DGs in the microgrid. The action of the droop control causes a deviation in the DC bus voltage which is exacerbated by the line impedance between the DG and the DC bus. In this paper, an advanced distributed secondary control scheme is proposed to simultaneously achieve accurate voltage regulation and cooperative current sharing in the islanded DC microgrid system. The proposed distributed secondary controller is introduced in the cyber layer of the system, and each controller shares information with neighbouring controllers via a communication network. The distributed technique maintains the reliability of the overall system if some part of the communication link fails. The proposed controller uses the type-II fuzzy logic scheme to adaptively select the secondary control parameters for an improved response of the controller. The sufficient conditions to guarantee the stability of the proposed controller are derived using the Lyapunov method. Comprehensive tests under different operating scenarios are conducted to demonstrate the robustness of the proposed control scheme.Item Advances in sintering of titanium aluminide : a review(Springer Science and Business Media LLC, 2022) Mphahlele, Mahlatse R.; Olubambi, Peter Apata; Olevsky, Eugene A.Item Airborne antenna systems for DVB-RCS solutions(IEEE, 2016) Ilcev, Stojce DimovThis paper introduces development and implementation of new Airborne Satellite Antenna (ASA) used for Very Small Aperture Terminal (VSAT) of Aeronautical Satellite Broadband System (ASBS) known as a Digital Video Broadcasting-Return Channel via Satellite (DVB-RCS). Directional High Gain Antenna (HGA) of ASA system usually needs to be protected by special radome and always positioned in the focus of satellite by a special antenna mechanical and electrical antenna tracking mechanism situated on the special stabilized pedestal. The several possible types of broadband ASA via different Radio Frequency (RF) band, such as Ku-band transceiving, airborne satellite broadband antenna, L and Ku-band antennas for DVB-RCS and Internet Protocol Television (IPTV) solutions, Ka-band transceiving antenna system for DVB-RCS solutions, Antenna Systems for Aeronautical Satellite Broadcasting (ASB) are discussed.Item Airborne satellite antenna steering and mounting systems(IEEE, 2016) Ilcev, Stojce DimovThis paper describes the steering and mount systems of Airborne Satellite Antenna (ASA) as a most important and sensitive part of both Aeronautical Mobile Satellite Communication (AMSA) and Aeronautical Mobile Satellite Broadcasting (AMSB) systems. In general, most of ASA solutions are small and easy to install onboard aircraft such as Low Gain Antenna (LGA). However, in particular, some of ASA systems are quite complex, relatively large and heavy, especially airborne High Gain Antenna (HGA) for Aircraft Earth Stations (AES), such as Inmarsat-H, High Speed Data (HSD), Swift64, SwiftBroadband and Digital Video Broadcasting-Return Channel via Satellite (DVB-RCS) antennas, so they need sophisticated steering and mounting systems. Over the past decade are developed the steering ASA broadband system, which main components are reduced considerably in both physical size and weight. These reductions are presented in this research that brings greater Effective Isotropic Radiated Power (EIRP) from satellite transponders coupled with GaAs-FET technology at the front end the satellite receiver. In this paper are also introduced existing types of mechanical, electrical, combined and other mount systems of ASA steering system. The ASA has to be always pointed towards the satellite in spite of aircraft motions. At this point, the mount airborne satellite system as one of the main requirements in designing the mobile satellite antenna systems from the technical and rational viewpoints is discussed.Item Airborne satellite navigation and other integrated antenna systems(IEEE, 2016) Ilcev, Stojce DimovThis paper is introducing the airborne satellite navigation and other integrated antenna systems for both weather and special navigation systems. In general, most of navigation antennas are omnidirectional, small and easy to install onboard aircraft, such as Global Navigation Satellite Antennas (GNSA) and other integrated antenna systems. However, in particular, some new developments of navigation antennas are providing miniaturized Global Navigation Satellite System (GNSS) antenna array technologies that significantly reduce the size of the antenna elements and the array dimensions. The passive and active GNSA for mobile applications including aeronautical are presented, which include all existing types of GNSS solutions. The GNSS antennas are usually omnidirectional, so they don’t need to be always pointed towards the satellite in spite of aircraft motions. In this paper are presented commercial aspects of the aircraft GNSS antenna technologies, their importance and integration with a digital beam-steering antenna electronics package. In addition, the solutions of different cost effective integrated antenna systems with GNSS antennas, such as airborne WAAS, XM, Weather, Sirius, ISL, DME, ADF, VOR, LOC, GS and other antenna systems are discussed.Item 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.Item Analysis of current Pulses in HeLa-Cell Permeabilization due to high voltage DC corona discharge(IEEE, 2016-09) Chetty, Nevendra K.; Chonco, Louis; Ijumba, Nelson M.; Chetty, Leon; Govender, Thavendran; Parboosing, Raveen; Davidson, Innocent EwaenCorona discharges are commonly utilized for numerous practical applications, including bio-technological ones. The corona induced transfer of normally impermeant molecules into the interior of biological cells has recently been successfully demonstrated. The exact nature of the interaction of the corona discharge with a cell membrane is still unknown, how-ever, previous studies have suggested that it is either the electric fields produced by ions or the chemical interaction of the reactive species that result in the disruption of the cell membrane. This disruption of the cell membrane allows molecules to permeate into the cell. Corona discharge current constitutes a series of pulses, and it is during these pulses that the ions and reactive species are produced. It stands to reason, therefore, that the nature of these corona pulses would have an influence on the level of cell permeabilization and cell destruction. In this investigation, an analysis of the width, rise-time, characteristic frequencies, magnitude, and repetition rate of the nanosecond pulses was carried out in order to establish the relationship between these factors and the levels of cell membrane permeabilization and cell destruction. Results obtained are presented and discussed.Item Analysis of electric-rubber tyred gantries for a more green Durban Container Terminal(International Organization Of Scientific Research (IOSR), 2015-06) Naicker, Rowen; Allopi, DhirenThe Durban Container Terminal (DCT) is currently the biggest and busiest container terminal in Africa and handles about 2.7-million TEUs a year. DCT handles approx. 70% of South Africa’s containers and generates 60% of South Africa’s revenue (Port of Durban, 2014). The work-horse of the container handling industry is the Rubber Tyred Gantry (RTG) crane. For over 50 years, these heavy duty cranes have been a staple at ports worldwide. Typically powered by diesel engines, these cranes require constant maintenance and fuel management to remain operational. In addition to costs, ports have begun to feel the pressure to become more “Green” by local authorities and governments.Pier 1, at DCT is currently utilizingRTGs. High energy consumption and high pollution result from RTGs operating around the clock. This entails a high cost burden for terminal operators and causes serious environmental pollution.An investigation into solutions to lessen operating costs, strengthen business competitiveness, and alleviate environmental pollution is presented in this paper. The results were analyzed and conclusions, as well as recommendations were made.Item Analysis of temperature and rainfall trends in Vaal-Harts irrigation scheme, South Africa(AJER, 2014) Adeyemo, Josiah; Otieno, Fredrick Alfred O.; Ojo, Olumuyiwa I.Abstract: - Agriculture is crucially dependent on the timely availability of adequate amount of water and a conducive climate. Temperature and rainfall patterns impact the availability of water for agricultural uses. Therefore, temperature and rainfall are twin important environmental factors in agricultural activities such as tillage, planting, irrigation and mechanization. The characteristics of the Vaal-Harts temperature data for year 1996 to 2010 and rainfall data for year 1983 to 2010 were examined in this study using statistical techniques. Basic statistical properties of the data were determined using the mean, variance, coefficient of variation and Pearson’s correlation coefficient. Temperature and rainfall observations with the average of about 17.44 were used. The minimum and maximum temperatures recorded were 9.720C and 23.520C. The Coefficient of variation (CV) was found to be about 29.59. Variance is a measure of how far a set of numbers is spread out; and the variance of this set of observations is 26.625. The average yearly temperature increases insignificantly by a constant of about 0.117 (p = 0.163; 95% CI: -0.054 – 0.288), while rainfall shows decreasing trend annually which means that the dry season will be drier. The involvement of non-zero values in the serial correlation indicated the significance of the deterministic component in the data. The results of this analysis enhance our understanding of the characteristics of air temperature and rainfall in the study area for effective planning of farming operations.Item Analysis of voltage rise phenomena in electrical power network with high concentration of renewable distributed generations(Springer Science and Business Media LLC, 2022-12) Akinyemi, Ayodeji Stephen; Musasa, Kabeya; Davidson, Innocent E.The increasing penetration levels of renewable distributed generation (RDG) into a power system have proven to bring both positive and negative impacts. The occurrence of under voltage at the far end of a conventional electrical distribution network (DN) may not raise concern anymore with RDGs integration into a power system. However, a penetration of RDGs into power system may cause problems such as voltage rise or over-voltage and reverse power flows at the Point of Common Coupling (PCC) between RDG and DN. This research paper presents the impact of voltage rise effect and reverse power flow constraint in power system with high concentration of RDG. The analysis is conducted on a sample DN, i.e., IEEE 13-bus test system, with RDG penetration by considering the most critical scenario such as low power demand in DN and a peak power injection by RDG. For studying the impact of voltage rise and reverse power flow, a mathematical model of a DN integrating RDG is developed. Furthermore, a controller incorporating an advance control-algorithm is proposed to be installed at PCC between DN and RDG to regulate the voltage rise effects and to mitigate the reverse power flow when operating at a worst critical scenario of minimum load and maximum generation from RDG. The proposed control strategy also mitigates the voltage–current harmonic distortions, improves the power factor, and maintain the voltage stability at PCC. The simulations are carried out using MATLAB/Simulink software. Finally, recommendations are provided for the power producers to counteract the effects of voltage rise at PCC. The study has demonstrated that, voltage at PCC can be sustained with a high concentration of RDG during a worst-case scenario without a reverse power flow and voltage rise beyond grid code limits.Item ANN’s vs. SVM’s for image classification(International ASET, 2012-08) Moorgas, Kevin Emanuel; Pillay, Nelendran; Governder, PoobalanIn this paper the dynamic performance of the artificial neural network is compared to the performance of a statistical method such as the support vector machine. This comparison is made with respect to an image classification application where the performance is compared with regards to generalization and robustness. Image vectors are compressed in order to reduce the dimensionality and the salient feature vectors are extracted with the principle component algorithm. The artificial neural network and the support vector machine are trained to classify images with feature vectors. A comparative analysis is made between the artificial neural network and the support vector machine with respect to robustness and generalization.Item The applicability of nanofiltration for the treatment and reuse of textile reactive dye effluent(AJOL, 2015) Chollom, Martha Noro; Rathilal, Sudesh; Pillay, Visvanathan Lingamurti; Alfa, DorcasThe main aim of the study was to test the feasibility of using nanofiltration (NF) processes for the treatment of reactive dye-bath effluents from the textile industry, in order to recover the water and chemicals (salts) for reuse purposes. The study of the reusability of nanofiltered water for dyeing has been given little or no attention. About 30% of reactive dyes remain unfixed on fibres; the unfixed dyes are responsible for the colouration in effluents. Membrane processes were employed to treat reactive dye-bath effluents to recover the salts and water. Investigations were conducted firstly with ultrafiltration (UF) used as a pre-treatment for NF. Secondly, evaluations were performed for 2 types of NF membranes (SR90 and NF90), in terms of quality of permeate produced and fluxes achieved for 2 different samples of effluent. The effect of cleaning on membrane performance was assessed. A reusability test was carried out on both permeate samples for dyeing light and dark shade recipes. The use of UF as pre-treatment to NF resulted in rejection of colloidal substances > 90% and a 15% flux improvement. Permeate from NF90 had a conductivity of 76 µS/cm and total organic carbon (TOC) of 20 mg/ℓ, as compared to SR90 which had a conductivity of 8.3 mS/cm and a TOC of 58 mg/ℓ. Light shade from NF90 gave satisfactory results on dyeing, with no colour difference. However a variation in colour was noticed when the medium sample was used to dye the light shade. Both NF permeates gave satisfactory results when used to dye the dark shades. Permeate from NF90 was within the accepted range for reuse, while permeate from SR90 had a higher salt recovery. Chemical cleaning resulted in 80% flux recovery. From the reusability test it was concluded that permeate from NF90 met the reuse criteria for feed water to the dye bath.Item The application and benefits of emerging digital technologies for Industry 4.0(2024-05) Govender, Nevek; Olanrewaju, Oludolapo A.Industry 4.0 technology advancement in recent years has enabled organizations to capitalize on new processes and tools towards making their businesses more profitable and efficient. 4IR Technologies such as Artificial Intelligence, Machine Learning, Condition Monitoring and Internet of Things have been at the forefront of the digital revolution and have transformed the way organizations do business. However, these complex technologies come with many challenges such as startup costs, lack of knowledge experts as well as the limited technology foundation for both business owners, as well as their employees. Therefore, this study looks at the current knowledge of Industry 4.0 from individuals in the industry, which will provide information on the current trends as well as possible knowledge gaps. The research also explores the benefits of Industry 4.0 technologies by using machine learning technology to elaborate on how we can enhance organizations’ efficiencies. The purpose of this study is to contribute towards the successful implementation of Industry 4.0 and provide encouragement for organizations to start their digital revolution. The research follows both a qualitative and quantitative analysis process. The qualitative data is analyzed from a survey of individuals which enables us to dissect and better identify the current trends, and possible knowledge gaps whilst the quantitative data is analyzed using machine learning software to highlight the potential that can be attained if organizations decide to implement these types of technologies. A content and grounded theory method was used to analyze the qualitative data, as the feedback from the interviewees was constantly reviewed and compared with each other whilst also comparing that to the initial hypothesis statements. It was seen that current trend is that individuals in the industry are excited and are aware of Industry 4.0, but there are still some challenges such as legacy machines, return of investment and knowledge gaps. For the quantitative data, a thematic analysis was used, in the form of machine learning software, to identify patterns in the results and interpret them in a way that can be understood better. From the analysis, it was seen that the machine learning software has a positive impact as the software was able to identify the highest points of failure as well as the type of failure which occurred for a machine. The timeline of failure was also deduced and therefore the organization would be able to put measures in place to restrict these failures from happening. The research provides great benefit for future researchers as well as organizations on topics relating to Industry 4.0 towards connecting the power of the technologies to create a smooth transition within the workplace. The survey analysis offers a better understanding of the current trends in the industry, and the research in general provides a foundation towards the understanding of Industry 4.0, and provides valuable insight on the greater role that new digital technologies play towards creating a better future for organizations.Item 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 EwaenGrid-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