An investigation of the challenges facing grade 10 science learners in sense-making of mechanics problems : a case study
- Authors: Malunguza, Julius
- Date: 2009
- Subjects: Science -- Study and teaching (Secondary) -- South Africa -- KwaZulu-Natal -- Case studies Mathematics -- Study and teaching (Secondary) -- South Africa -- KwaZulu-Natal -- Case studies Physical sciences -- Study and teaching (Secondary) -- South Africa -- KwaZulu-Natal -- Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1647 , http://hdl.handle.net/10962/d1003529
- Description: The research study was conducted at Ixopo High School, an English medium, former model-C, co-educational school in Kwazulu-Natal. The research is located within an interpretive paradigm and is informed by the constructivism theoretical framework. The learners and educators who participated in this research study did so voluntarily. The principal objective of this case study was to investigate the challenges faced by 30 Grade 10 Science learners in understanding the problems posed in the mechanics section of the Physics syllabus. This investigation was carried out using two learning strategies: problem solving and practical work. Various authors have noted some sections in the Physics syllabus are often misunderstood by the learners, for different reasons. From the literature and from the author’s personal experience it was found that mechanics is a topic that the learners of different races and age groups find difficult to conceptualise. In general, learners have misconceptions and make errors in Physical Sciences. Often educators view children’s errors and misconceptions in terms of low intelligence, low mathematical aptitude, perceptual difficulties or learning disabilities instead of attempting to discover the real causes of the errors. Educators need to find out why the learners make these mistakes, in order to help them. In most cases Mathematics forms a basic common element in scientific study. Hence, science learners need to be able to deal with numbers, operations, symbols and mathematical formulae. The term “science” embraces a very wide area of subject matter. Different learners will have widely differing interests within the many subdivisions of this field. This presents a problem when preparing learners for the scientific language they will need to study different branches of science. This implies that failure to understand the meaning of words or symbols inevitably impairs communication. The data analysed was collected using a variety of data collection tools. The main data generation tools were science tasks, structured interviews and group interviews and questionnaires. The analysis revealed that learners were lacking in mathematical skills and science register (terminology). Both first and second language English speakers encountered problems in science register but the study found that the problem was more pronounced in the latter. The findings of this study also highlighted that learners understand how to think mathematically when they are resourceful, flexible, and efficient in their dealing with new mathematical problems in mechanics. However, mathematical problem solving performance is built on the foundation of basic mathematical knowledge. The study suggested that even when the challenges of a general understanding of English as the medium of instruction and scientific language (register) are overcome, learners are still challenged by mathematical problem solving strategies; reading and writing of science; making meanings of symbols and signs; graphs and scientific mathematical equations in sense making of mechanics problems.
- Full Text:
- Date Issued: 2009
- Authors: Malunguza, Julius
- Date: 2009
- Subjects: Science -- Study and teaching (Secondary) -- South Africa -- KwaZulu-Natal -- Case studies Mathematics -- Study and teaching (Secondary) -- South Africa -- KwaZulu-Natal -- Case studies Physical sciences -- Study and teaching (Secondary) -- South Africa -- KwaZulu-Natal -- Case studies
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1647 , http://hdl.handle.net/10962/d1003529
- Description: The research study was conducted at Ixopo High School, an English medium, former model-C, co-educational school in Kwazulu-Natal. The research is located within an interpretive paradigm and is informed by the constructivism theoretical framework. The learners and educators who participated in this research study did so voluntarily. The principal objective of this case study was to investigate the challenges faced by 30 Grade 10 Science learners in understanding the problems posed in the mechanics section of the Physics syllabus. This investigation was carried out using two learning strategies: problem solving and practical work. Various authors have noted some sections in the Physics syllabus are often misunderstood by the learners, for different reasons. From the literature and from the author’s personal experience it was found that mechanics is a topic that the learners of different races and age groups find difficult to conceptualise. In general, learners have misconceptions and make errors in Physical Sciences. Often educators view children’s errors and misconceptions in terms of low intelligence, low mathematical aptitude, perceptual difficulties or learning disabilities instead of attempting to discover the real causes of the errors. Educators need to find out why the learners make these mistakes, in order to help them. In most cases Mathematics forms a basic common element in scientific study. Hence, science learners need to be able to deal with numbers, operations, symbols and mathematical formulae. The term “science” embraces a very wide area of subject matter. Different learners will have widely differing interests within the many subdivisions of this field. This presents a problem when preparing learners for the scientific language they will need to study different branches of science. This implies that failure to understand the meaning of words or symbols inevitably impairs communication. The data analysed was collected using a variety of data collection tools. The main data generation tools were science tasks, structured interviews and group interviews and questionnaires. The analysis revealed that learners were lacking in mathematical skills and science register (terminology). Both first and second language English speakers encountered problems in science register but the study found that the problem was more pronounced in the latter. The findings of this study also highlighted that learners understand how to think mathematically when they are resourceful, flexible, and efficient in their dealing with new mathematical problems in mechanics. However, mathematical problem solving performance is built on the foundation of basic mathematical knowledge. The study suggested that even when the challenges of a general understanding of English as the medium of instruction and scientific language (register) are overcome, learners are still challenged by mathematical problem solving strategies; reading and writing of science; making meanings of symbols and signs; graphs and scientific mathematical equations in sense making of mechanics problems.
- Full Text:
- Date Issued: 2009
Between self and author : an autoethnographic approach towards the crafting of reflexive compositions in post graduate drama studies
- Authors: Moyo, Awelani Lena
- Date: 2009
- Subjects: Drama -- Study and teachng (Higher) College and school drama
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2143 , http://hdl.handle.net/10962/d1002375
- Description: This thesis explores the merits of reflexivity in the processes of creating a performance and of performing research in Drama Studies. In it, I make a case for the validity of autobiographical material as an aid to generating such reflexivity. Through an autoethnographic case study of my work entitled Compositions (a series of performance projects) in which I focus on the theme of migration, I provide an indepth account of my experiences, focusing specifically on the interrelated concerns of body, space and journey in my ritualistic performance. My examination explores the dynamic effects of liminality within identity politics, through which I foreground several issues of concern which I have encountered as an emerging scholar and theatremaker working within an academic institution. I propose that the process of studying drama in a University ultimately requires one to continually negotiate a range of subject positions, whilst finding connections between these various identities that one may take up during the course of one’s studies. By developing an awareness of the overlapping of such identities and inhabiting the spaces in-between subject positions, I demonstrate how taking into account one’s personal lived experience can help illuminate one’s understanding of both the work of art and the research report, as well as the broader contexts in which such practice-based work exists. I illustrate how such an understanding has ultimately maximised the knowledge and learning that I have gathered, and has contributed to the crucial project of developing my authorial voice in writing and performance, which is central to the aims of the Master of Arts degree in Drama.
- Full Text:
- Date Issued: 2009
- Authors: Moyo, Awelani Lena
- Date: 2009
- Subjects: Drama -- Study and teachng (Higher) College and school drama
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2143 , http://hdl.handle.net/10962/d1002375
- Description: This thesis explores the merits of reflexivity in the processes of creating a performance and of performing research in Drama Studies. In it, I make a case for the validity of autobiographical material as an aid to generating such reflexivity. Through an autoethnographic case study of my work entitled Compositions (a series of performance projects) in which I focus on the theme of migration, I provide an indepth account of my experiences, focusing specifically on the interrelated concerns of body, space and journey in my ritualistic performance. My examination explores the dynamic effects of liminality within identity politics, through which I foreground several issues of concern which I have encountered as an emerging scholar and theatremaker working within an academic institution. I propose that the process of studying drama in a University ultimately requires one to continually negotiate a range of subject positions, whilst finding connections between these various identities that one may take up during the course of one’s studies. By developing an awareness of the overlapping of such identities and inhabiting the spaces in-between subject positions, I demonstrate how taking into account one’s personal lived experience can help illuminate one’s understanding of both the work of art and the research report, as well as the broader contexts in which such practice-based work exists. I illustrate how such an understanding has ultimately maximised the knowledge and learning that I have gathered, and has contributed to the crucial project of developing my authorial voice in writing and performance, which is central to the aims of the Master of Arts degree in Drama.
- Full Text:
- Date Issued: 2009
Mariculture as a means to add value to the east coast rock lobster Panulirus homarus rubellus subsistence fishery : a physiological approach to define transport and growout protocols for wild caught juveniles
- Authors: Kemp, Justin Oliver Gordon
- Date: 2009
- Subjects: Lobster fisheries -- South Africa , Lobster culture -- South Africa , Lobsters -- Growth -- South Africa , Mariculture -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5299 , http://hdl.handle.net/10962/d1005144
- Description: In a context of declining capture fisheries and public pressure for greater access to marine resources, marine aquaculture is receiving increasing interest from the South African government as a means to increase the diversity of economic activities in coastal regions, thereby providing employment and reducing poverty. The east coast rock lobster Panulirus homarus rubellus is currently harvested by subsistence fisherman along the former Transkei coastline of south-east South Africa and presents a possible opportunity for ongrowing wild juvenile lobsters in culture facilities. Lack of compliance coupled with poor enforcement of the minimum size limit (65 mm carapace length) has resulted in the ongoing harvest of undersize size lobsters by subsistence fishers. Generally, fishers either consume these undersize lobsters or sell them to tourists for low prices. In line with international trends in rock lobster aquaculture, interest has subsequently arisen in the possibilities of ongrowing these undersize lobsters as a means of adding value to the P. h rubellus resource for subsistence fishers. The aim of this physiological study was to assess the biological feasibility of harvesting, transporting and culturing wild caught juvenile lobsters, thereby provide empirical data to inform the development of suitable transport and culture protocols. The experimental objectives were to asses the effect of temperature on growth and survival of P. h. rubellus, as well as the effects of a suite of extrinsic and intrinsic factors on ammonia excretion and oxygen consumption. Juvenile lobsters were collected by hand from near-shore reefs (2-15 m depth) off Mdumbi in the former Transkei, Eastern Cape Province and transported by road (7 hours) to the Port Alfred Marine Research Laboratory where they were held in a recirculating culture system. The effect of temperature over a range of 9.7 °C (18.9±0.7 to 28.6±1.5 °C) on the growth and survival of juvenile P. h. rubellus fed a diet of fresh mussel flesh was investigated. Specific growth rate (SGR) was significantly different between temperatures (p = 0.01), with the highest values recorded for the 24 °C and 28 °C treatments. There was no significant difference in moult increment (MI) between temperatures, however, intermoult period (IMP) differed significantly between temperatures (p = 0.0015) with mean IMP lowest at 24 °C, although not significantly different from the means of the 26 °C and 28 °C treatments. IMP was highest at 19 °C and 21 °C. Apparent feed intake was significantly different between treatments (p < 0.0001) and exhibited a strong positive correlation with increasing temperature. Food conversion ratio (FCR) differed significantly between temperatures (p = 0.02) with 24 °C exhibiting the most efficient FCR. The results for growth rate and food conversion efficiency suggested that 24 °C is optimal for the growout of juvenile P. h. rubellus. In the second study, the effect of body weight, emersion, daily rhythm, feeding and ambient ammonia on the total ammonia nitrogen (TAN) excretion rate was investigated. Body weight (n = 16, range of 16.8 – 322 g) was positively correlated to daytime TAN excretion rate (mg h⁻¹). Re-immersion after one hour emersion in a moist environment was characterized by a significant increase in TAN excretion rate for the first hour compared to pre-immersion levels. The amount of TAN excreted during this period was as expected if basal TAN excretion rates were maintained during emersion. TAN excretion rates returned to pre-emersion levels by the end of the second hour. There was no evidence of a daily rhythm in TAN excretion rate for P. h. rubellus. TAN excretion rates were elevated following feeding. An initial peak in TAN excretion rate after seven hours (7.58 times pre-feeding rate) was followed by a smaller peak after 13 hours (6.69 times pre-feeding rate). TAN excretion rate dropped to levels not significantly different from pre-feeding levels after 23 hours and consistently returned to pre-feeding levels after 42 hours. The TAN excretion rates of lobster exposed for two hours to an ambient TAN concentration of 1.02±0.10 mg l⁻¹ and 2.3± 0.2 mg l⁻¹ were not significantly different from TAN excretion rates recorded at low ambient water TAN prior to exposure. Exposure to an ambient TAN concentration of 4.45±0.78 mg l⁻¹ had a significant effect on the TAN excretion rate, with pronounced ammonia uptake occurring for all animals at this concentration. The third study investigated the effects of body weight, diurnal rhythm, feeding and emersion on lobster oxygen consumption. Body weight was positively correlated to both standard and active oxygen consumption (mg O2 h⁻¹) while body weight was negatively correlated to mass-specific standard oxygen uptake (mg O2 g⁻¹ h⁻¹). Diurnal rhythm exhibited a strong effect on the lobsters oxygen consumption, with average night time values 67% greater than those recorded during the day. This was related to activity driven by intrinsic nocturnal foraging behaviour. Feeding resulted in a classic specific dynamic action (SDA) response, with postprandial oxygen consumption increasing to a peak before decreasing gradually to preprandial levels. Emersion resulted in a significant increase in oxygen consumption, with lobsters rapidly recovering to pre-emersion levels after four hours. Results from these studies suggest that the capture, transport and culture of juvenile P. h. rubellus is biologically feasible. Empirical data generated were used to provide recommendations regarding species optimised transport and culture protocols. A purge time of 48 hours before transport is suggested to ensure that ammonia excretion and oxygen consumption are at basal levels. Furthermore, emersed transport for a period of one hour is characterised by rapid recovery upon re-immersion. In order to prevent the accumulation of stressors, it is suggested that consecutive periods of emersion are interjected with recovery periods (five hours) in water to allow the removal of accumulated ammonia and repayment of the oxygen debt incurred. The recorded ammonia rates indicate that a biological filter size of 4.8 m³ is recommended for 1000 kg of fed lobsters in a culture situation, although this can be reduced considerably if lobsters are being held without feeding (0.72 m³). A flow rate of 112 l kg⁻¹ h⁻¹ is required to meet the metabolic requirements of lobsters. Bottlenecks to the viable commercial culture of P. h. rubellus, and the ability of this practice to provide the socio-economic benefits that were envisioned, are discussed.
- Full Text:
- Date Issued: 2009
- Authors: Kemp, Justin Oliver Gordon
- Date: 2009
- Subjects: Lobster fisheries -- South Africa , Lobster culture -- South Africa , Lobsters -- Growth -- South Africa , Mariculture -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5299 , http://hdl.handle.net/10962/d1005144
- Description: In a context of declining capture fisheries and public pressure for greater access to marine resources, marine aquaculture is receiving increasing interest from the South African government as a means to increase the diversity of economic activities in coastal regions, thereby providing employment and reducing poverty. The east coast rock lobster Panulirus homarus rubellus is currently harvested by subsistence fisherman along the former Transkei coastline of south-east South Africa and presents a possible opportunity for ongrowing wild juvenile lobsters in culture facilities. Lack of compliance coupled with poor enforcement of the minimum size limit (65 mm carapace length) has resulted in the ongoing harvest of undersize size lobsters by subsistence fishers. Generally, fishers either consume these undersize lobsters or sell them to tourists for low prices. In line with international trends in rock lobster aquaculture, interest has subsequently arisen in the possibilities of ongrowing these undersize lobsters as a means of adding value to the P. h rubellus resource for subsistence fishers. The aim of this physiological study was to assess the biological feasibility of harvesting, transporting and culturing wild caught juvenile lobsters, thereby provide empirical data to inform the development of suitable transport and culture protocols. The experimental objectives were to asses the effect of temperature on growth and survival of P. h. rubellus, as well as the effects of a suite of extrinsic and intrinsic factors on ammonia excretion and oxygen consumption. Juvenile lobsters were collected by hand from near-shore reefs (2-15 m depth) off Mdumbi in the former Transkei, Eastern Cape Province and transported by road (7 hours) to the Port Alfred Marine Research Laboratory where they were held in a recirculating culture system. The effect of temperature over a range of 9.7 °C (18.9±0.7 to 28.6±1.5 °C) on the growth and survival of juvenile P. h. rubellus fed a diet of fresh mussel flesh was investigated. Specific growth rate (SGR) was significantly different between temperatures (p = 0.01), with the highest values recorded for the 24 °C and 28 °C treatments. There was no significant difference in moult increment (MI) between temperatures, however, intermoult period (IMP) differed significantly between temperatures (p = 0.0015) with mean IMP lowest at 24 °C, although not significantly different from the means of the 26 °C and 28 °C treatments. IMP was highest at 19 °C and 21 °C. Apparent feed intake was significantly different between treatments (p < 0.0001) and exhibited a strong positive correlation with increasing temperature. Food conversion ratio (FCR) differed significantly between temperatures (p = 0.02) with 24 °C exhibiting the most efficient FCR. The results for growth rate and food conversion efficiency suggested that 24 °C is optimal for the growout of juvenile P. h. rubellus. In the second study, the effect of body weight, emersion, daily rhythm, feeding and ambient ammonia on the total ammonia nitrogen (TAN) excretion rate was investigated. Body weight (n = 16, range of 16.8 – 322 g) was positively correlated to daytime TAN excretion rate (mg h⁻¹). Re-immersion after one hour emersion in a moist environment was characterized by a significant increase in TAN excretion rate for the first hour compared to pre-immersion levels. The amount of TAN excreted during this period was as expected if basal TAN excretion rates were maintained during emersion. TAN excretion rates returned to pre-emersion levels by the end of the second hour. There was no evidence of a daily rhythm in TAN excretion rate for P. h. rubellus. TAN excretion rates were elevated following feeding. An initial peak in TAN excretion rate after seven hours (7.58 times pre-feeding rate) was followed by a smaller peak after 13 hours (6.69 times pre-feeding rate). TAN excretion rate dropped to levels not significantly different from pre-feeding levels after 23 hours and consistently returned to pre-feeding levels after 42 hours. The TAN excretion rates of lobster exposed for two hours to an ambient TAN concentration of 1.02±0.10 mg l⁻¹ and 2.3± 0.2 mg l⁻¹ were not significantly different from TAN excretion rates recorded at low ambient water TAN prior to exposure. Exposure to an ambient TAN concentration of 4.45±0.78 mg l⁻¹ had a significant effect on the TAN excretion rate, with pronounced ammonia uptake occurring for all animals at this concentration. The third study investigated the effects of body weight, diurnal rhythm, feeding and emersion on lobster oxygen consumption. Body weight was positively correlated to both standard and active oxygen consumption (mg O2 h⁻¹) while body weight was negatively correlated to mass-specific standard oxygen uptake (mg O2 g⁻¹ h⁻¹). Diurnal rhythm exhibited a strong effect on the lobsters oxygen consumption, with average night time values 67% greater than those recorded during the day. This was related to activity driven by intrinsic nocturnal foraging behaviour. Feeding resulted in a classic specific dynamic action (SDA) response, with postprandial oxygen consumption increasing to a peak before decreasing gradually to preprandial levels. Emersion resulted in a significant increase in oxygen consumption, with lobsters rapidly recovering to pre-emersion levels after four hours. Results from these studies suggest that the capture, transport and culture of juvenile P. h. rubellus is biologically feasible. Empirical data generated were used to provide recommendations regarding species optimised transport and culture protocols. A purge time of 48 hours before transport is suggested to ensure that ammonia excretion and oxygen consumption are at basal levels. Furthermore, emersed transport for a period of one hour is characterised by rapid recovery upon re-immersion. In order to prevent the accumulation of stressors, it is suggested that consecutive periods of emersion are interjected with recovery periods (five hours) in water to allow the removal of accumulated ammonia and repayment of the oxygen debt incurred. The recorded ammonia rates indicate that a biological filter size of 4.8 m³ is recommended for 1000 kg of fed lobsters in a culture situation, although this can be reduced considerably if lobsters are being held without feeding (0.72 m³). A flow rate of 112 l kg⁻¹ h⁻¹ is required to meet the metabolic requirements of lobsters. Bottlenecks to the viable commercial culture of P. h. rubellus, and the ability of this practice to provide the socio-economic benefits that were envisioned, are discussed.
- Full Text:
- Date Issued: 2009
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