Photovoltaic-powered wireless communication system for rural schools outside national utility grid
- Authors: Kaseke, Richmore https://orcid.org/0000-0002-8295-5016
- Date: 2007-02
- Subjects: Photovoltaic power systems , Photovoltaic power generation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/29032 , vital:76492
- Description: Access to global information is inarguably one of the key ways of bringing development to any community. In developing worlds, many rural schools lie outside both the Internet Service Provider’s (ISP) cable network and the national utility grid. Rapid developments in information and communication technology (ICT) continue to widen the digital divide between urban and rural schools. In South Africa, although these rural areas are outside the ISP’s cable network, they enjoy excellent mobile (cellular) communications network coverage. Fortunately, leading mobile operators in the country (MTN and Vodacom) have incorporated mobile data packet services into their cellular communication networks since 2002. A stand-alone photovoltaic (PV) system for powering ICT equipment in off grid rural schools was designed and installed; and its performance monitored. Performance of the system was considered in two categories, which are; cost and service performance. In cost performance, return on investment (ROI) and payback period (PB) are the two critical considerations. The PV system designed in this study gave an impressive ROI and PB of 286percent and 5 years, respectively. In order to monitor and evaluate the service performance a data acquisition system (DAS) was designed and installed. Besides proving the potential of PV in powering ICT equipment, results from the DAS also suggested a more efficient way of employing PV as a power source for powering equipment that is based on Switched-Mode Power Supply Units. Concurrent and continuous change in irradiance and temperature result in a four-segment pattern of rising and falling module efficiency throughout the day. Generally, modules produce more energy on cooler sunny days than hotter sunny days. Infrared (IR) Thermography was also used as part of both indoor and outdoor module tests. During indoor tests at pre-deployment stage, IR Thermography showed development of hot spots in mismatched cells of reverse-biased modules. On the outdoors, IR Thermography reiterated the effect of bird droppings on module surfaces byshowing hot spots forming on areas covered by the droppings. For internet connectivity, a customized Mobile Internet Device (MIDevice) was designed, built and tested. The device allows remote computer systems to be connected to the Internet via the already existing mobile communication network using General Packet Radio Services (GPRS). An entire rural school local area network (LAN) can be connected to the Internet via a single MIDevice. An experimental setup was designed in order to monitor and evaluate performance of GPRS in specific and mobile Internet solutions in general. Results obtained proved that GPRS can indeed be a solution for remote Internet connectivity in rural schools. In order to improve performance of GPRS or mobile Internet connections, caching, pop-up blocking and proxy filtering are necessary. , Thesis (MSc) -- Faculty of Science and Agriculture, 2007
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Assessment of antibacterial potentials of Garcinia Kola seed extracts and their interactions with antibiotics
- Authors: Sibanda, Thulani
- Date: 2007
- Subjects: Drug resistance in microorganisms , Garcinia , Antibiotics
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/19236 , vital:43038
- Description: The antibacterial potency of the extracts of the seed of Garcinia kola (bitter kola) was investigated in this study against a panel of referenced, environmental and clinical bacterial strains. The killing rates of the active extract as well as their potential for combination antibacterial therapy with standard antibiotics were also elucidated using standard procedures. The aqueous and acetone extracts of the seed were screened for activity against 27 bacterial isolates. The aqueous extract exhibited activity mainly against Gram positive organisms with Minimum inhibitory concentration (MIC) values ranging from 5 mgml-1 – 20 mgml-1, while the acetone extract showed activity against both Gram negative and Gram positive organisms with MIC values ranging from 10 mgml-1 - 0.156 mgml-1. The acetone extract also showed rapid bactericidal activity against Staphylococcus aureus ATCC 6538 with a 3.097 Log10 reduction in counts within 4 hours at 0.3125 mgml-1 and a 1.582 Log10 reduction against Proteus vulgaris CSIR 0030 at 5 mgml-1 after 1 hour. In addition, the aqueous, methanol and acetone extracts of the seeds also exhibited activity against four clinical strains of Staphylococcus isolated from wound sepsis specimens. The MIC values for the aqueous extract were 10 mgml-1 for all the isolates while the acetone and methanol extracts had lower values ranging from 0.3125 - 0.625 mgml-1. The acetone extract was strongly bactericidal against Staphylococcus aureus OKOH3 resulting in a 2.70 Log10 reduction in counts at 1.25 mgml-1 within 4 hours of exposure and a complete elimination of the organism after 8 hours. The bactericidal activity of the same extract against Staphylococcus aureus OKOH1 was weak, achieving only a 2.92 Log10 reduction in counts at 1.25 mgml-1 (4× MIC) in 24 hours. In the test for interactions between the acetone extract of the seeds and antibiotics, synergistic interactions were observed largely against Gram positive organisms using the FIC indices, (indices of 0.52 - 0.875) with combinations against Gram negatives yielding largely antagonistic interactions (indices of 2.0 to 5.0). Synergy (≥ 1000 times or ≥ 3 Log10 potentiation of the bactericidal activity) against both Gram negative and Gram positive organisms was detected by time kill assays mainly involving the antibiotics tetracycline, chloramphenicol, amoxycillin and penicillin G. Combinations involving erythromycin and ciprofloxacin consistently gave antagonistic or indifferent interactions. We conclude that the acetone extract of Garcinia kola seeds possess strong bactericidal activities against both Gram positive and Gram negative organisms and can be therapeutically useful in the treatment of bacterial infections including the problematic staphylococcal wound infections. In addition, the acetone extract can be a potential source of broad spectrum resistance modifying compounds that can potentially improve the performance of antibiotics in the treatment of drug resistant infections. , Thesis (MSc)-- Microbiology, University of Fort Hare, 2007
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An evaluation of the brand perception of FortHare University amongst Grade 12 learners of the Buffalo City Municipality
- Authors: Mtetwa, Webster
- Date: 2006-11
- Subjects: Branding (Marketing)
- Language: English
- Type: Honours theses , text
- Identifier: http://hdl.handle.net/10353/24509 , vital:63050
- Description: The research seeks to determine the overall perception potential students have of the University of Fort Hare. This was done through comparing the university with other nearby universities based on the reputation, image, characteristics of each university and other factors. The research will build brand awareness of the university amongst potential students. It will also publicise and assist the university in initiating strategies meant to inform potential students about the advantages of learning at the University of Fort Hare. The research will also provide reasons as to why students do not intend/intend to register at the University Fort Hare. The reasons behind the students’ perceptions were detected which were attributed to the qualities possessed by the University. Students also reflected that their brand choice was attributed from brand awareness in that, the students were not informed about the qualifications offered by the universities. , Thesis (BCom Hons) -- Faculty of Management and Commerce, 2006
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Role of early childhood development practitioners in developing children’s oral language in three selected centres in Buffalo City
- Authors: Nodlela, Lumka
- Subjects: Early childhood education , Language acquisition , Early childhood teachers
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10353/27887 , vital:70453
- Description: The child's language development is one of the most notable achievements of the preschool years. Children must develop their language skills effectively to access the curriculum. Practitioners of Early Childhood Development (ECD) have a substantial impact on children's spoken language development. As a result, three centers in the Buffalo City Education District are the subject of this dissertation's investigation into how ECD practitioners contribute to children's oral language development. The applicable theory used in the study was Vygotsky's Zone of Proximal Development (ZPD) theory. The existent phenomenon was examined using the interpretivist research paradigm and the qualitative research methodology. The study used a phenomenological research approach to examine the perspectives, functions, and experiences of individuals (ECD practitioners) in the growth of children's oral language. The study used purposive sampling. Participants were purposively selected as because of their proximity to the researcher’s workplace. The fifteen practitioners in the chosen ECD centers were interviewed in semi-structured interviews, and data were also gathered through observations. Following transcription, sorting, and categorization, the gathered data were thematically analysed using themes inferred from the study objectives. The study's conclusions showed that ECD specialists help children improve their oral language in a useful way. As a result, they require training in the creation and application of various strategies for fostering oral language in young children. Short courses will also assist practitioners in fostering the overall development of children. One of the key elements that interferes with effective teaching and learning at ECD centers, though, is a shortage of resources. , Thesis (MEd) -- Faculty of Education, 2023
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