A case study of the readability of two grade 4 natural sciences textbooks currently used in South African schools
- Authors: Sibanda, Lucy
- Date: 2013
- Subjects: Science -- Study and teaching (Primary) -- Textbooks Reading comprehension -- Study and teaching (Primary) -- South Africa English language -- Textbooks for foreign speakers English language -- Study and teaching (Primary) -- Foreign speakers Education, Primary -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1892 , http://hdl.handle.net/10962/d1006083
- Description: This thesis examines the readability of two grade 4 Natural Sciences textbooks currently used in South African schools. Being important sources of classroom input, particularly in grade 4 where learners are reading to learn, textbooks should be readable. That the Natural Sciences subject is only introduced in grade 4 makes the assessment of Natural Sciences textbooks at this level significant. The goal of this research therefore, is to assess the readability of two grade 4 Natural Sciences textbooks and their understandability by learners who speak English as an additional language. The goal of assessing the Natural Sciences textbooks is achieved by the use of cloze and traditional comprehension tests, classic readability formulae, textual analysis and teacher interviews. Cloze and traditional comprehension tests are used to test learners’ understanding of the textbooks and classic readability formulae are meant to assess the grade levels of the textbooks. The tests gauge learner understandability while readability formulae establish text readability. Textual analysis allows the assessment of text readability on the basis of more factors than those accommodated by readability formulae. The textual analysis also helps to identify the readability factors supporting or impeding readability. Teacher interviews are conducted to better understand the teachers’ perceptions on the readability of the Natural Sciences textbooks. The major findings of the study are that the two Natural Sciences textbooks used in the study are generally above the reading level of the intended readers, grade 4 learners and that the participating learners do not understand these textbooks. The challenges with the readability of the textbooks stem mainly from the vocabulary and concepts used in the textbooks which are not well explained.
- Full Text:
- Date Issued: 2013
- Authors: Sibanda, Lucy
- Date: 2013
- Subjects: Science -- Study and teaching (Primary) -- Textbooks Reading comprehension -- Study and teaching (Primary) -- South Africa English language -- Textbooks for foreign speakers English language -- Study and teaching (Primary) -- Foreign speakers Education, Primary -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1892 , http://hdl.handle.net/10962/d1006083
- Description: This thesis examines the readability of two grade 4 Natural Sciences textbooks currently used in South African schools. Being important sources of classroom input, particularly in grade 4 where learners are reading to learn, textbooks should be readable. That the Natural Sciences subject is only introduced in grade 4 makes the assessment of Natural Sciences textbooks at this level significant. The goal of this research therefore, is to assess the readability of two grade 4 Natural Sciences textbooks and their understandability by learners who speak English as an additional language. The goal of assessing the Natural Sciences textbooks is achieved by the use of cloze and traditional comprehension tests, classic readability formulae, textual analysis and teacher interviews. Cloze and traditional comprehension tests are used to test learners’ understanding of the textbooks and classic readability formulae are meant to assess the grade levels of the textbooks. The tests gauge learner understandability while readability formulae establish text readability. Textual analysis allows the assessment of text readability on the basis of more factors than those accommodated by readability formulae. The textual analysis also helps to identify the readability factors supporting or impeding readability. Teacher interviews are conducted to better understand the teachers’ perceptions on the readability of the Natural Sciences textbooks. The major findings of the study are that the two Natural Sciences textbooks used in the study are generally above the reading level of the intended readers, grade 4 learners and that the participating learners do not understand these textbooks. The challenges with the readability of the textbooks stem mainly from the vocabulary and concepts used in the textbooks which are not well explained.
- Full Text:
- Date Issued: 2013
Investigation into the technical feasibility of biological treatment of precious metal refining wastewater
- Authors: Moore, Bronwyn Ann
- Date: 2013
- Subjects: Sewage -- Purification -- Biological treatment -- South Africa Sewage -- Purification -- Activated sludge process -- South Africa Water reuse -- South Africa Flotation -- South Africa Platinum mines and mining -- Waste disposal -- South Africa Platinum mines and mining -- Economic aspects -- South Africa Mine water -- Environmental aspects -- South Africa Platinum mines and mining -- Waste minimization -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3888 , http://hdl.handle.net/10962/d1002013
- Description: The hydrometallurgical refining of platinum group metals results in large volumes of liquid waste that requires suitable treatment before any disposal can be contemplated. The wastewater streams are characterized by extremes of pH, high inorganic ion content (such as chloride), significant residual metal loads and small amounts of entrained organic compounds. Historically these effluents were housed in evaporation reservoirs, however lack of space and growing water demands have led Anglo Platinum to consider treatment of these effluents. The aim of this study was to investigate whether biological wastewater treatment could produce water suitable for onsite reuse. Bench-scale activated sludge and anaerobic digestion for co-treatment of an acidic refinery waste stream with domestic wastewater were used to give preliminary data. Activated sludge showed better water treatment at lab scale in terms of removal efficiencies of ammonia (approximately 25%, cf. 20% in anaerobic digestion) and COD (70% cf. 43% in digestion) and greater robustness when biomass health was compared. Activated sludge was consequently selected for a pilot plant trial. The pilot plant was operated on-site and performed comparably with the bench-scale system, however challenges in the clarifier design led to losses of biomass and poor effluent quality (suspended solids washout). The pilot plant was unable to alter the pH of the feed, but a two week maturation period resulted in the pH increasing from 5.3 to 7.0. Tests on algal treatment as an alternative or follow-on unit operation to activated sludge showed it not to be a viable process. The activated sludge effluent was assessed for onsite reuse in flotation and it was found that there was no significant difference between its flotation performance and that of the process water currently used, indicating the effluent generated by the biological treatment system can be used successfully for flotation. Flotation is the method whereby minerals refining operations recover minerals of interest from ore through the addition of chemicals and aeration of the ore slurry. Target minerals adhere to the bubbles and can be removed from the process.
- Full Text:
- Date Issued: 2013
- Authors: Moore, Bronwyn Ann
- Date: 2013
- Subjects: Sewage -- Purification -- Biological treatment -- South Africa Sewage -- Purification -- Activated sludge process -- South Africa Water reuse -- South Africa Flotation -- South Africa Platinum mines and mining -- Waste disposal -- South Africa Platinum mines and mining -- Economic aspects -- South Africa Mine water -- Environmental aspects -- South Africa Platinum mines and mining -- Waste minimization -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3888 , http://hdl.handle.net/10962/d1002013
- Description: The hydrometallurgical refining of platinum group metals results in large volumes of liquid waste that requires suitable treatment before any disposal can be contemplated. The wastewater streams are characterized by extremes of pH, high inorganic ion content (such as chloride), significant residual metal loads and small amounts of entrained organic compounds. Historically these effluents were housed in evaporation reservoirs, however lack of space and growing water demands have led Anglo Platinum to consider treatment of these effluents. The aim of this study was to investigate whether biological wastewater treatment could produce water suitable for onsite reuse. Bench-scale activated sludge and anaerobic digestion for co-treatment of an acidic refinery waste stream with domestic wastewater were used to give preliminary data. Activated sludge showed better water treatment at lab scale in terms of removal efficiencies of ammonia (approximately 25%, cf. 20% in anaerobic digestion) and COD (70% cf. 43% in digestion) and greater robustness when biomass health was compared. Activated sludge was consequently selected for a pilot plant trial. The pilot plant was operated on-site and performed comparably with the bench-scale system, however challenges in the clarifier design led to losses of biomass and poor effluent quality (suspended solids washout). The pilot plant was unable to alter the pH of the feed, but a two week maturation period resulted in the pH increasing from 5.3 to 7.0. Tests on algal treatment as an alternative or follow-on unit operation to activated sludge showed it not to be a viable process. The activated sludge effluent was assessed for onsite reuse in flotation and it was found that there was no significant difference between its flotation performance and that of the process water currently used, indicating the effluent generated by the biological treatment system can be used successfully for flotation. Flotation is the method whereby minerals refining operations recover minerals of interest from ore through the addition of chemicals and aeration of the ore slurry. Target minerals adhere to the bubbles and can be removed from the process.
- Full Text:
- Date Issued: 2013
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