Design, construction and performance evaluation of an agitated portable biogas digester under greenhouse-regulated temperature
- Authors: Mutungwazi Asheal
- Date: 2017
- Subjects: Sewage -- Purification -- Anaerobic treatment Green technology Renewable energy sources
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/9055 , vital:34222
- Description: Biogas yield in anaerobic digesters is negatively affected by low temperatures during cold seasons and nights, temperature fluctuations and inefficient agitation. Electrical heating and underground digester installations have been used to help minimise these effects but the high cost of electrical heating, infeasibility of underground installations in some terrains, inefficient agitation and difficult maintenance continue to be major set-backs to high biogas yields. In this study a 100 ℓ, agitated, portable carbon steel digester housed within a greenhouse, whose operation temperature is automatically maintained at an optimum of 35 ± 1 oC by means of an ON/OFF electronic circuit for ventilation control through a suitably sized window and insulation offered by an air film trapped in-between a double layer of polyethylene plastic covering of the greenhouse, was designed. Cow dung from a dairy farm at the University of Fort Hare with total solids (TS), volatile solids (VS), chemical oxygen demand (COD) and ammonia nitrogen content of 162348.67 mg/ℓ, 116543.98 mg/ℓ, 37 879 mg/ℓ and 128 - 235 mg/ℓ respectively was used for the performance evaluation of the digester. Analysis of the biogas produced starting from day 6 of the 31-day retention period showed a specific biogas yield of 0.036 m3/kgVSadded and a methane yield of 55percent. The optimum pH maintained was 7.2 and the COD reduction achieved during the digestion period was 61percent. This simple, easy to construct, inexpensive yet efficient design will lead to improved biogas yields and quality and faster dissemination of the biogas technology.
- Full Text:
- Date Issued: 2017
- Authors: Mutungwazi Asheal
- Date: 2017
- Subjects: Sewage -- Purification -- Anaerobic treatment Green technology Renewable energy sources
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/9055 , vital:34222
- Description: Biogas yield in anaerobic digesters is negatively affected by low temperatures during cold seasons and nights, temperature fluctuations and inefficient agitation. Electrical heating and underground digester installations have been used to help minimise these effects but the high cost of electrical heating, infeasibility of underground installations in some terrains, inefficient agitation and difficult maintenance continue to be major set-backs to high biogas yields. In this study a 100 ℓ, agitated, portable carbon steel digester housed within a greenhouse, whose operation temperature is automatically maintained at an optimum of 35 ± 1 oC by means of an ON/OFF electronic circuit for ventilation control through a suitably sized window and insulation offered by an air film trapped in-between a double layer of polyethylene plastic covering of the greenhouse, was designed. Cow dung from a dairy farm at the University of Fort Hare with total solids (TS), volatile solids (VS), chemical oxygen demand (COD) and ammonia nitrogen content of 162348.67 mg/ℓ, 116543.98 mg/ℓ, 37 879 mg/ℓ and 128 - 235 mg/ℓ respectively was used for the performance evaluation of the digester. Analysis of the biogas produced starting from day 6 of the 31-day retention period showed a specific biogas yield of 0.036 m3/kgVSadded and a methane yield of 55percent. The optimum pH maintained was 7.2 and the COD reduction achieved during the digestion period was 61percent. This simple, easy to construct, inexpensive yet efficient design will lead to improved biogas yields and quality and faster dissemination of the biogas technology.
- Full Text:
- Date Issued: 2017
Implementation of visual arts education in one technical and vocational education and training college in the Eastern Cape : the voices of lecturers and students
- Authors: Dayimani, Mbulelo
- Date: 2017
- Subjects: Curriculum planning Vocational education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/12744 , vital:39318
- Description: It can be observed that students actively participate in the learning process of education in our country, and the curriculum gives expression to the knowledge, skills and values worth learning in South African schools and institutions. However, Technical and Vocational Education Training (TVET) Colleges still continue using traditional learning methods, in which the teacher is in the centre, devoid of artistic culture, and practical work. These implementation methods and techniques have been identified as less motivating for students especially for those with no background in Visual Arts (VA) in high school. The aim of this study therefore was to investigate the views of students and lecturers on the implementation of Visual Arts Education (VAE) in the TVET Colleges in the Eastern Cape. This study was premised from a qualitative research approach and therefore interpretivist paradigm was relevant in assisting the researcher making sense of the data gathered. Face-to-face interviews were used to collect the data from five lecturers and fifteen students in N4 level. The interviews were tape-recorded. The research showed that Visual Arts Education can be an engine that drives creativity and innovation in schools, higher Education institution and all tertiary level settings. It is also reasoned that the visual arts, as with other creative arts disciplines, will not become important and necessary engines for change in education without a determination to critically review its implementation starting with how VAE policies are used in the TVET Colleges. It also emerged from the study that the policies that are available for VAE in the College relate to syllabus as well as assessment and enrolment procedures. The syllabus was found by the lecturers to be inappropriate and less motivating for the students. Also the assessment procedure was revealed to be done according to both practical and theoretical components based on task, test, and practical moderation. However, the practical component was based on seventy five percent and the theory on twenty five percent thereby disadvantaging learners who do not have the theoretical background of the VAE. The study therefore recommends that policies that are used in TVET Colleges for VAE need to be revised, re-applied and implemented so as to cater for the needs of lecturers and students pursuing a career in Visual Arts or VAE.
- Full Text:
- Date Issued: 2017
- Authors: Dayimani, Mbulelo
- Date: 2017
- Subjects: Curriculum planning Vocational education
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/12744 , vital:39318
- Description: It can be observed that students actively participate in the learning process of education in our country, and the curriculum gives expression to the knowledge, skills and values worth learning in South African schools and institutions. However, Technical and Vocational Education Training (TVET) Colleges still continue using traditional learning methods, in which the teacher is in the centre, devoid of artistic culture, and practical work. These implementation methods and techniques have been identified as less motivating for students especially for those with no background in Visual Arts (VA) in high school. The aim of this study therefore was to investigate the views of students and lecturers on the implementation of Visual Arts Education (VAE) in the TVET Colleges in the Eastern Cape. This study was premised from a qualitative research approach and therefore interpretivist paradigm was relevant in assisting the researcher making sense of the data gathered. Face-to-face interviews were used to collect the data from five lecturers and fifteen students in N4 level. The interviews were tape-recorded. The research showed that Visual Arts Education can be an engine that drives creativity and innovation in schools, higher Education institution and all tertiary level settings. It is also reasoned that the visual arts, as with other creative arts disciplines, will not become important and necessary engines for change in education without a determination to critically review its implementation starting with how VAE policies are used in the TVET Colleges. It also emerged from the study that the policies that are available for VAE in the College relate to syllabus as well as assessment and enrolment procedures. The syllabus was found by the lecturers to be inappropriate and less motivating for the students. Also the assessment procedure was revealed to be done according to both practical and theoretical components based on task, test, and practical moderation. However, the practical component was based on seventy five percent and the theory on twenty five percent thereby disadvantaging learners who do not have the theoretical background of the VAE. The study therefore recommends that policies that are used in TVET Colleges for VAE need to be revised, re-applied and implemented so as to cater for the needs of lecturers and students pursuing a career in Visual Arts or VAE.
- Full Text:
- Date Issued: 2017
“The Hellenistic ruler cult and Ptolemy I’s quest for legitimacy”
- Authors: Ntuli, Sihle
- Date: 2017
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/6097 , vital:21031
- Description: Alexander III died suddenly in Babylon in 323 BC. With Philip III Arrhidaeus in a mentally deficient state and Alexander IV not being of age, Alexander died without a suitable heir. The task of succeeding one of the most storied legacies in the ancient world was left to the generals of Alexander III. On his deathbed, Alexander was asked who should lead the Macedonians, of which he allegedly replied “the strongest”. Thus began the process of selecting the individual who would succeed Alexander the Great, which ended up becoming a contentious task due to Macedonian succession customs. Subsequently the ‘Successors’ quarrelled over who should succeed Alexander as the true successor. The wars of the Successors are founded on an issue of legitimacy that qualifies the notion of the strongest. Being deemed the true successor of Alexander the Great meant the opportunity to continue a period of Macedonian dominance following the reigns of Philip II and Alexander III. Alexander III is hailed as one of the most extraordinary individuals of the ancient world with his imperial campaigns being widely documented, political stability being pinpointed as one of the Macedonian strong points during the period of their dominance. The ruler cult is a point of reference for the explaining the relative political stability throughout the reign of Alexander the Great. The ruler cult can be understood as a sociopolitical construct that hybridized the notion of the ruler with that of a religious leader. The oriental influence of Alexander’s campaigns in Asia would inform the customs and practices of the divine ruler. The Macedonians’ ability to establish a presence in foreign territories made such a social construct a necessity in the task of centralizing of minds for political stability. Alexander’s rendition of the cult informed the formalized Ptolemaic ruler cult. The similarities and differences of the renditions help us to understand this political tool that Ptolemy I required in order to be deemed the true successor of Alexander the Great. The following will be an investigation into whether Ptolemy I is able to attain legitimacy, firstly as a successor to Alexander the Great, secondly as Pharaoh of Egypt.
- Full Text:
- Date Issued: 2017
- Authors: Ntuli, Sihle
- Date: 2017
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/6097 , vital:21031
- Description: Alexander III died suddenly in Babylon in 323 BC. With Philip III Arrhidaeus in a mentally deficient state and Alexander IV not being of age, Alexander died without a suitable heir. The task of succeeding one of the most storied legacies in the ancient world was left to the generals of Alexander III. On his deathbed, Alexander was asked who should lead the Macedonians, of which he allegedly replied “the strongest”. Thus began the process of selecting the individual who would succeed Alexander the Great, which ended up becoming a contentious task due to Macedonian succession customs. Subsequently the ‘Successors’ quarrelled over who should succeed Alexander as the true successor. The wars of the Successors are founded on an issue of legitimacy that qualifies the notion of the strongest. Being deemed the true successor of Alexander the Great meant the opportunity to continue a period of Macedonian dominance following the reigns of Philip II and Alexander III. Alexander III is hailed as one of the most extraordinary individuals of the ancient world with his imperial campaigns being widely documented, political stability being pinpointed as one of the Macedonian strong points during the period of their dominance. The ruler cult is a point of reference for the explaining the relative political stability throughout the reign of Alexander the Great. The ruler cult can be understood as a sociopolitical construct that hybridized the notion of the ruler with that of a religious leader. The oriental influence of Alexander’s campaigns in Asia would inform the customs and practices of the divine ruler. The Macedonians’ ability to establish a presence in foreign territories made such a social construct a necessity in the task of centralizing of minds for political stability. Alexander’s rendition of the cult informed the formalized Ptolemaic ruler cult. The similarities and differences of the renditions help us to understand this political tool that Ptolemy I required in order to be deemed the true successor of Alexander the Great. The following will be an investigation into whether Ptolemy I is able to attain legitimacy, firstly as a successor to Alexander the Great, secondly as Pharaoh of Egypt.
- Full Text:
- Date Issued: 2017
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