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Enhancement of power transfer capacity in bipolar HVDC system
No full textThesis (Master of Engineering (Electrical Engineering))--Cape Peninsula University of Technology, 2019Economic growth that leads to sustained increase in electricity demand resulted into extension of AC systems. This is due to the correlation between the increase in population and power consumption. It was anticipated that by now the power consumption in developing and emerging countries is expected to have increased by 220%. When such happens the power system will be experiencing problems of uncontrolled loop-flows, overloading and excess of short circuit levels, system instabilities and outages. In order to ensure the continuity of supply, power system enhancement and interconnections needs to have been in place in a form of higher voltage levels, new transmission technologies and renewable energies. As anticipated, power consumption increased to the point where power systems are constrained. The purpose of the study is to enhance the inherent power transmission capacity of the overhead lines on the overloaded existing sub-transmission and distribution networks. FACTS have been developed with the aim to better load flow and voltage control. However the devices help in increasing transport capacity, in avoiding loop power flows, in improving transient and dynamic stability etc but do not increase the inherent transmission capacity of a line. Point-to-point VSC-based HVDC transmission was used as an alternative to upgrade the existing right of way corridors. This was achieved by transformation of an existing AC line with a DC one, making maximum use of conductors and towers with up to 4 times transfer capacity increase. The studies were modelled in the software tool Digsilent Power Factory. Three scenarios were simulated under short circuit and contingency conditions where voltage was being monitored on the bursars and the capacity together with overloading were monitored on the HV lines of substations. In chapter one, the background objectives and significance of the study are presented followed by the insight on to classic HVDC transmission networks in chapter two. This matured technology was studied to trace the increased potential of HVDC applications. VSC-based converters are presented in chapter three. Amongst others, the dynamic voltage support, the system stability and the higher power transfer capacity offered by VSC based converters were the most beneficial pertaining to this thesis. Due to challenges encountered in acquiring the land for new electricity infrastructure. It has been noted that urban electrical system require easy solutions that can be attained within urban boundaries and shot lead times.as a consequence the replacement/conversion of existing AC overhead lines with DC is presented in chapter four. Among the system instability problems encountered on the network at study, Voltage instability was a key issue to be addressed and chapter five presents categories of voltage stability and mitigations thereof. In chapter six the modelling and simulation of the existing AC network to underpin the problem statement for different contingencies is presented. The results are recorded so that they can be compared to results obtained after VSC-HVDC link incorporation. Chapter seven touches on the modelling of VSC-HVDC link on Digsilent Power Factory. Following in chapter eight are the busbar voltage and the loading results after VSC-HVDC incorporation. It was evident that VSC-HVDC incorporation mitigated low voltage and overloading problems in the network. A concluding statement was reached to say the dynamic support of the AC voltage at each converter terminal improved the voltage stability while the transfer capability of the sending and receiving end AC system was improved
The study of African orature in the form of animation : the case of Sankuru in the Democratic Republic of Congo
No full textThesis (MTech (Graphic Design))--Cape Peninsula University of Technology, 2019The research aims to demonstrate the extent to which animation can be used to depict the performance aspect of African oral literature by taking into consideration the various forms of meaning-making that accompany a typical oral literature event. Oral tradition is among the oldest traditions in African culture; it is the channel through which the moral values and belief systems of African peoples were transmitted from older generations to younger ones. African oral literature, or simply orature1, has arguably survived the risk of extinction through publication. Libraries throughout the world feature books on African poetry and written collections of African folktales. However, the one aspect that cannot be depicted in a written format is the element of performance2. Finnegan (2007) states that performance is intrinsic to African oral literature; and, without it, the oral experience cannot be fully realised and still maintain the identity of African narration. Using a selected instance of orature in the Sankuru district in the Democratic Republic of Congo (DRC), this autoethnographic study explores the extent to which animation can be used to capture the intrinsic components of African oral literature. To incorporate the various semiotic devices that are displayed during an orature performance, a multimodal framework was used as a means for 'looking beyond' spoken language. The findings of this exploratory research point to the fact that Sankuru performers embody the essence of their respective performances. The latter are a combination of signs and signifiers which are deeply rooted in the culture as they are imbedded in the performer's words, in the clothes he or she wears, and in the settings within which the performances are held. Thus the performances cannot be divorced from their cultural context. The practical component that resulted from the research suggests an approach in which animation is used to depict and stage the world of the storytelling performance by bringing elements of the story 'into existence' while weaving said depiction with essential semiotic components of the performance
An information system framework for validating physical addresses against identity document in the Republic of Angola
No full textThesis (MTech (Information Technology))--Cape Peninsula University of Technology, 2019In the Republic of Angola, home addresses are printed on the national identity (ID) document. However, the physical addresses that are stored in the government's agency (Ministry of Homeland) database and printed on individuals ID document, are often different from citizens' actual residences. As a result, the databases are often filled with duplicated, incorrect and inaccurate physical addresses. This makes it more challenging for the government and its agencies to monitor, trace and manage activities, as well as provide services to individuals and communities. Consequently, the security of the country is also at stake as it enacts fraudulent acts and makes it more difficult for law enforcement agencies to address and uncover criminal acts and intents. Therefore, the aim of the study was to develop an information system framework, which can be used to address the challenges that duplication and inaccuracy of physical addresses in the ID system pose to the Republic of Angola including the government service delivery and citizen's activities. Based on the aim of the study the objectives were: (1) to identify and examine the factors of deficiencies in the current system whereby wrong, duplicate, inaccurate or inconsistent physical addresses are printed on identity documents of individuals; (2) Examine both technical and non-technical factors that can improve the current system. In achieving the objectives of the study, qualitative data was collected from the community of Luanda in Angola, and from one of the Ministries within the Angolan government. Due to ethical considerations, the Ministry was named "Ministry of Homeland" and it was used as a case in the study. This was mainly because this is the Ministry that deals directly with the issuance of IDs and storage of physical addresses. The data was collected through a semi-structured interview technique. The data was hermeneutically analysed from the interpretive approach. The analysis was guided by the lens of the duality of structure from structuration theory perspective. Seven factors were found to be the constraining and enabling factors of the efficiency and deficiency in the ID issuance process in the Republic of Angola. The findings were further interpreted towards the development of the information system framework which can be used to address the challenges that the duplications and inaccuracy of physical addresses in the ID system pose to the Angolan government and its people
The establishment of normal adult reference values for a selected panel of laboratory analytes in South Africa
No full textThesis (PhD (Biomedical Sciences))--Cape Peninsula University of Technology, 201
Multicomponent cystals of selected Hydroxycinnamic Acids
No full textThesis (Master of Applied Sciences in Chemistry)--Cape Peninsula University of Technology, 2019.The solid-state modification of a given active pharmaceutical ingredient is a desired way to alter its physicochemical properties, such as solubility or bioavailability. Multicomponent crystals constructed with p-coumaric acid (pCA) and trans-ferulic acid (TFA) were investigated with the amines (2-amino-4-picoline (2A4MP), 2-amino-6-picoline (2A6MP), 4,4’-bipyridine (BIPY) and pyridine (PYR)) and 1,4-dioxane (DX). Eight compounds were prepared using the slow evaporation technique. pCA formed one co-crystal, two salts and two solvates while TFA formed a co-crystal, a salt and a solvate. The crystal structures were determined using single crystal Xray diffraction crystallography. Further characterisations were done using thermal analysis and FTIR spectroscopy. Z’ > 1 was observed for some of the crystal structures of pCA. The solvent assisted grinding method for preparation of these compounds was not successful as they all resulted in unknown compounds. The Hirshfeld analysis confirmed that the crystal structures generated in this study were dominated by hydrogen bonding (O-H•••O, O-H•••N and C-H•••O) and the π-π stacking had minimal contribution in the packing arrangement of the new solid forms
Barriers encountered by women in career development towards senior management positions in management industry
No full textThesis (MTech (Business Administration in Project Management))--Cape Peninsula University of Technology, 2019The purpose of this study was to investigate the barriers encountered by women in career development towards senior management levels in management industry in organizations in Cape Town. To attempt to delve deeper into the possible reasons why there is less women in career development towards management/leadership positions. Why are the less women at the management levels in the country as whole, where when are in the majority? The researcher believed that women make better deals than men do. Women make more bills and get more support for those bills than male counterparts. This can also be reasoned to the way women operate in business, organization in the world as whole. This is also why the author wanted to identify women based factors that impede the progress of women in their effort to move to other higher levels. The rate of unemployment in South Africa is an ongoing issue, however this has made the South African government to an emphasis on women in career development. The objectives of this study were to identify factors that may contribute to the failure of woman success. In South Africa globally there is less representation of women than men at senior management levels. To address the issue of less representation of woman in organizations in Cape Town. To find a solution to the barriers encountered by women in their career advancement. A questionnaire was generated and used as tool to obtain contributions to fulfil the research questions. This study was based on material collected from Female employees in organizations in Cape Town. The findings are as follows: It seems to be absent is investment in understating the role of women managers ‘representation in organizations, where by organizations become proactive rather than reactive. This is as true for staff development as it is for retaining. Organisations could further capitalize in management industry to ensure that women are taken care of. The recommendations and conclusions were based on the researcher's understanding and interpretation of the meaning of the data that was collected. Based on findings, the results indicated that education has a significant relationship with career advancement is in consensus with findings; it has been shown that the majority of female employees are stuck as general staff support in the organization. Whereas the study indicated that only 3% of the female employees are in Head of operations, followed by 6% of Operations managers, followed by 7% of senior managers
Useful energy utilisation of integrated solar PV and thermal module with storage device
No full textThesis (PhD (Electrical Engineering))--Cape Peninsula University of Technology, 2019Lack of electrical energy has always been an issue for human society development. Several studies point out the expansion and integration of renewable energies into the society to solve the energy crisis. Renewable energies promote sustainable energy development, environmental, social, and economic sustainability throughout their life cycle. The integration of renewable energies, especially in the area of the photovoltaic technology becomes important, as it demotes the rates of consumption of non-renewable resources, therefore, decreasing the fossil fuels dependencies. A photovoltaic system has a low output conversion rate. Integrating photovoltaic and thermal (PV/T) system can improve the photovoltaic conversion efficiency. However, the overall efficiency of the PV/T is always compromised as one of the sub-system performance might overtake the other. This research work is developed to enhance the knowledge of the thermal performance of photovoltaic models and also offered alternatives to improve and co-generate thermal and electrical energy. The purpose of the proposed PV/T model is to analyse the cooling method and the possibility of partially converting photovoltaic electrical energy into useful heat source (for hot water). The working fluid plays the role of cooling the PV cells, therefore, boosting the PV cell performance. The working fluid would collect the useful heat energy through the pipes in a closed loop attached at the back of the PV panel. The study also is aimed at proposing automated intelligent solutions for energy management to adjust the useful heat transfer capacity to working fluid based on energy demand and weather conditions to balance the thermal and electrical energy. The overall research method was based on a theoretical analysis, the review of essential articles, the design of the most appropriate concepts, mathematical modelling and analysis of the proposed PV/T system. Also, an adequate control strategy based on the energy management algorithm to provide multi-functional energy performance was established to prioritise the energy balance according to demand. The simulation model of the PV/T system was developed with MATLAB/Simulink software to predict system performance with reasonable accuracy and to analyse the main phenomena related to thermal behaviour. The simulation result of the proposed PV/T model under different operational conditions evaluated the cooling the PV cells and heating the working fluid. The outcomes turned out to be productive and cost-effective. Also, the PV modules can yield better electrical energy performance due to the cooling effect of the PV cells. The results revealed that the proposed system met cooling and heating based on the demands
Performance improvement of LTE and LTE advanced networks
No full textThesis (Master of Engineering (Electrical, Electronic and Computer Engineering))--Cape Peninsula University of Technology, 2019It has been a decade with Long Term Evolution (LTE) as mobile radio access technology (RAT) and in this, period it became the favoured broadband communication technology. LTE, as a 3rd Generation Project Partnership (3GPP) technology, has entered the frozen stage, no future enhancement beyond release 14 only minor revisions. While over the same time, the revolution in mobile handsets, and internet of thing (IoT) "connected devices" have expedited the surge in desire for more data resources, which are ubiquitous. Undoubtedly LTE as a technology has been the most dominant wireless medium, in transporting broadband services for both voice and data. Thus the efficient operations of an LTE Heterogeous network(HetNets) are of ultimate importance, both in terms of the load balance and the performance delivered to users. The packet scheduling is an advanced radio resource management (RRM) mechanism, which plays a key fundamental role in the delivery of time-frequency resources to users in uplink and downlink. Thus the operation of the packet scheduler determines the overall LTE network performance and also the services level for the user's example (e.g.) the quality of service (QoS), throughput. In this study, two packet algorithm schemes were proposed, firstly one that focuses on modulation and coding scheme(MCS), fairness and QoS called Flexible Fair Allocation Scheme (FFAS). It was evaluated with contemporary algorithms Least Load and Greedy algorithm. The results for FFAS were superior for both simulations scenarios. The second proposed packet scheduling algorithm area of focus was with massive machine type communication (MTC) for HetNets. Where the PR-M2M scheduler was proven to deliver superior outcomes in distributing resources for a human to human(H2H) as well as for Device to device(D2D) communication. The simulations were piloted in Matlab using the Vienna LTE Downlink System simulator, where we were able to conduct diverse network analysis. The network simulations produced outcomes which indicated FFAS and PR-M2M are the best algorithms for LTE Advanced networks. In conclusion, it should be noted while access to additional spectrum is an issue, optimal uti-lization of current license spectrum is of utmost importance. With carrier aggregation as an LTE Advanced feature, operators are able to efficiently use the available spectrum. The sched-uling algorithms proposed plays a pivotal roll in controlling how the resources are distributed to users. Therefore these two scheduling schemes will be contributing to improved performance of LTE Advanced networks
Cloud computing adoption readiness by small enterprises in Cape Town, South Africa
No full textThesis (MTech (Information Technology))--Cape Peninsula University of Technology, 2019In contemplation of business sustainability and competitive participation in the market, there is a compelling need for small, medium and micro-sized enterprises (SMMEs) to embrace technology innovations. However, the adoption rate and use of Information and Communications Technology (ICT) specifically by Small Enterprises (SEs) is still very low. The slow adoption rate is mainly attributed to the non-availability of sufficient resources in SEs. Cloud Computing (CC) technology promises to provide the needed computing capacities to SEs at affordable cost. SEs do not have a clear understanding of what CC entails and are therefore not able to determine their readiness level for CC adoption. This research aimed to explore the extent of the CC adoption readiness of SEs in the city of Cape Town as well as SEs’ level of understanding of CC technology. Two primary research questions with two sub-questions each were posed. The primary research questions were formulated as follows: 1) To what extent are SEs prepared for cloud computing technology adoption? 2) How do SEs determine their readiness for the adoption of cloud computing? The research was qualitatively designed, with a subjectivist and interpretivist approach. Semi-structured interviews by means of an interview guide were conducted with SEs in Cape Town and surroundings. The SEs were purposively selected using the non-random sampling technique. The research was conducted according to the code of ethics as prescribed by the University. Respondents had to consent to participating in the research, and the researcher continuously provided assurance of confidentiality to the respondents. The research findings offer direction on the understanding, awareness, and readiness of SEs in general in Cape Town. Some of the main findings of the research revealed that SEs do not have a clear understanding of CC technology, consequently, it could not clearly be determined whether SEs are ready for the adoption. This has led to drawing conclusions that point to the low level of CC adoption readiness of SEs
Bi-rads final assessment categories in breast cancer patients
No full textThesis (MSc (Radiography))--Cape Peninsula University of Technology, 2019INTRODUCTION: The Breast Imaging Reporting and Data System (BI-RADS) was developed by the American College of Radiology (ACR). The BI-RADS is an internationally accepted method of assessing and reporting on mammograms and breast ultrasound images. The BI-RADS consists of a lexicon (descriptors) and assessment categories. The ACR aimed to standardise mammography reporting and placing the findings in the appropriate assessment category. The aim of this study was to establish the accuracy of the BI-RADS assessment categories for mammography and breast ultrasound images in women diagnosed with breast cancer. METHOD: Data were retrieved from 77 patients who were diagnosed with breast cancer from 1 January 2013 to 31 December 2014. Seven did not meet the inclusion criteria and were excluded. The study sample size was 70 (n=70) patients. All mammography reports included a BI-RADS assessment category of all patients diagnosed with breast cancer within the study period. These reports were analysed and compared with histopathology results. The BI-RADS assessment category and descriptors were collected from the mammogram reports; the histopathology report indicated the type of breast cancer. All reports were obtained from the patients' folders at the research site. In addition, questionnaires were distributed among radiologists to assess whether their experience and training had an influence on the accuracy of reporting in the BI-RADS assessment categories. Descriptive and inferential statistical analysis was used for data analysis. RESULTS: The most common malignancy diagnosed was invasive ductal carcinoma with a total of 70% (n=54), followed by ductal carcinoma in situ with 10.4% (n=8) and invasive lobular carcinoma with 9.1% (n=7). The histology results confirmed breast cancer for all BI-RADS 4 and 5 assessment categories. The mammogram was able to detect 93.5% of abnormalities and breast ultrasound 84.4% of abnormalities in this study sample. Breast ultrasound was used as an adjunct to mammography and hence an overall combined diagnostic rate was 100%. Mammography descriptors: The more common malignancy findings were spiculated mass margin, 35.1% (n=27). Ultrasound descriptors: The more common malignancy findings were hypoechoic echo pattern, 55.8% (n=43). There was no significant association (p=0.152) between the radiologists' years of experience and BI-RADS 3, 4 and 5 assessment category reporting. Of the 15 responses, 67% agreed that the BI-RADS standardises breast imaging reporting and reduces confusion, 33% agreed that the BI-RADS allows better communication between radiologists and referring physicians, and 40% agreed that the BI-RADS clarifies further management for patients by helping to stratify risk management. CONCLUSION: The outcome of this study indicated that the use of BI-RADS assessment categories is useful for predicting the likelihood of malignancy when used correctly. The outcome of BI-RADS 4 and BI-RADS 5 had a positive predictive value of 100%, which corresponded well with histology results. The descriptor findings suggested that spiculated mass margins, irregular-shaped masses, hypoechoic echo pattern and posterior shadowing were high predictors of malignancy and warranted a placement in the BI-RADS 5 assessment category