Effects of the use of manipulative materials on grade nine learners’ performance in fractions in public high schools in Chris Hani West Education District, South Africa
- Authors: Adom, George
- Date: 2020-01
- Subjects: Mathematics -- Study and teaching -- Activity programs , Acalculia in children
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/19371 , vital:43058
- Description: The purpose of this study was to investigate the effects of the use of manipulative concrete materials on grade 9 learners’ performance in fractions in public high schools in Chris Hani west education district, in the Eastern Cape Province of the Republic of South Africa. Two hundred and fifty (250) grade nine (9) learners, whose ages ranged between 13-16 years, and ten (10) educators teaching grade nine mathematics, were selected from 40 public high schools with the use of stratified, systematic random sampling, convenience and purposive sampling methods. One hundred and twenty-five (125) learners were put into the experimental group, and another one hundred and twenty-five (125) learners were put into a control group through systematic random sampling method. Pre-test, Post-test, and Control group quasi-experimental design were used as research designs to collect data. Two research instruments were developed. These included: A Fractions Achievement Test (FAT), and Students Questionnaire on Manipulative Concrete Materials (SQMCM). The experimental group were taught with the Manipulative Concrete Materials (Cuisenaire rods, Fraction bar/Fraction title, Paper folding and Computer assisted manipulative), whilst the control group was taught through the lecture method. Four (4) null hypotheses were generated and tested at 0.05 level of significance. The data collected were analysed using Analysis of Covariance (ANCOVA) to find the Mean, Standard Deviation and t-test. The mean and standard deviation were used to compare the pre-test and post-test results between the Experimental group and the Control group. The analysed results of the means, standard deviations and t-tests were used to reject the null hypotheses. The analysed results were illustrated as followed: Cuisenaire rods pre-test (mean = 8.372, SD=1.770), post-test (mean = 12,428, SD=4.732), t=13,024 p< 0.05. Hypothesis (H01) was rejected : Fraction tiles/fraction bars pre-test (mean = 8.372, SD=1.770), post-test (mean = 11,42, SD=3.67), t=12,10 p< 0.05. Hypothesis (H02) was rejected : Paper folding pre-test (mean = 8.372, SD=1.770), post-test (mean = 11,792, SD=4.256), t=12,024 p< 0.05. Hypothesis (H03) was rejected : Computer assisted manipulative pre-test (mean = 8.372, SD=1.770), post-test (mean = 12,212, SD=4.569), t=12,801 p< 0.05. Hypothesis (H04) was also rejected. The comparison of the mean scores and iv standard deviation between the Experimental groups and Control groups indicated that there was no significant difference in the Pre-test in all cases. On the other hand, the mean scores and standard deviations between the Experimental group and Control group in the Post-test showed a vast difference in all cases. There were improvement in the mean scores, and slightly difference in the standard deviations in the Experimental groups, whilst there were drops in the mean scores and standard deviations of the Control groups in all cases. From the studies, there was an indication that manipulative concrete materials have significant effects on grade nine learner’s performance in fractions. It was therefore suggested that manipulative concrete materials should be incorporated into the instructions of fractions in mathematics. , Thesis (PhD) -- Faculty of Education, 2020
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- Date Issued: 2020-01
Enablements and constraints of articulation arrangements and agreements between technical and vocational education and training colleges and one Comprehensive University in the Eastern Cape, South Africa
- Authors: Mantashe, Lunga Xolisa https://orcid.org/0000-0003-1711-8358
- Date: 2020-01
- Subjects: Articulation (Education) , Technical education , Vocational education
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21624 , vital:51736
- Description: This study explored enablements and constraints of Articulation Arrangements and Agreements (AAAs) between Technical and Vocational Education and Training Colleges (TVETs) and one Comprehensive University (CU) in the Eastern Cape, South Africa. The constructs of structure, culture, and agency as propounded by Margaret Archer were employed as the theoretical lens of the study. Each of Archer’s constructs is independent and their dynamic interplay has causal influence on whether AAAs are facilitated or hindered. A qualitative single embedded case study design was applied, owing to the interpretivist paradigm the research chose. To this end, seven participants were purposively chosen and interviewed, and two university documents were analyzed, namely the draft University Articulation Guidelines (UAGs) and the university general prospectus. It was found that there were no formal, written, or even verbal TVET-CU agreements. Articulation happened on an ad hoc basis. The change of role-players in the institutional role array played a role in the non-existence and collapse of AAAs. On admissions, challenges included disparate requirements between National Senior Certificate and National Certificate Vocational. Nevertheless, articulation-enabling practices manifested themselves in the credit transfer decisions of participants. However, the Work Integrated Learning (WIL) component of a TVET national diploma programme enjoyed no parity with non-TVET and university cosrordinated experiential learning in some departments. In addition, there were nuanced views over the (inherent) value of WIL which affected its ultimate treatment. Finally, the study found that though TVET-university national diploma programmes were somewhat similar and enabled AAAs, they were still misaligned at the level of design and interface, resulting in duplication of content, waste of time, and state resources. The university also did not have TVET programmes in mind in the design and review of programmes. The researcher deduced a conceptual framework for understanding and explaining how and why TVET-university AAAs succeed or fail. The framework touts the importance of having knowledgeable, articulation- cultured and acculturated leadership and officials (responsible for admissions, credit transfer, and RPL) as crucial for exploiting structural enablements and creatively circumventing inherent structural constraints, including challenging subtle ideas which may wittingly or unwittingly harbor views of TVET programmes as inferior. To this end, it is suggested that there be an establishment of an articulation office to coordinate AAAs that take a form of a hybrid model whereby there would be a combination of multilateral, direct in-house, and franchise TVET-CCU AAAs. The framework should also resolve programme design alignment issues by incorporating CAT and RPL principles, including other articulation instruments during curriculum analysis. RPL should equally be applied in the treatment of TVET WIL. , Thesis (PhD) -- Faculty of Education, 2020
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- Date Issued: 2020-01
Integration of nanostructured metal sulfides into titanium (iv) oxide for high performance dye sensitized solar cell
- Authors: Agoro, Adedoyin Mojeed
- Date: 2020-01
- Subjects: Nanostructured materials , Sulfur compounds
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/21523 , vital:48857
- Description: The work in this thesis describes synthesis, characterization and integration of nanostructured metal sulfides into titanium (IV) oxide for high performance dye sensitized solar cell. The synthesised single source precursors were evaluated using TGA, FTIR, , UV-Vis, PL,1H and 13CNMR, SEM, EDS, HRTEM, XRD, AFM, Raman, I-V, CV, Bode plot and EIS. TGA revealed the thermal degradation and quantified the mass percentage of metal sulphides as 33percent, 45percent and 27percent for CuS, PbS and SnS nanoparticles, respectively. FTIR analysis showed bands at 1580-1450 cm-1, and 1060-940 cm-1 tentatively assigned to C-N and C-S stretching frequencies correspondingly. The (M-S) stretching was observed at 577-406 cm-1 for the complexes using bis(N-di-isopropyl-N-octyldithiocarbamato) as primary ligands. IR spectra of bis(N-1,4-phenyl-N-(4-morpholinedithiocarbamato) as secondary ligands suggested the presence of (C-N) vibrations at 1508-1513 cm-1 for the complexes and 1507-1584 cm-1 for the ligands. The bands in the region of 973-1030 cm-1 were assigned to the complexes and 974- 983 cm-1 were attributed to the ligands, whereas vibration frequencies at 416-625 cm-1 were Nelson's Choice were included in these preliminary variety trials (PVTs) as checks. Twenty-five hybrids expressing high values for the Smith – Hazel selection index were identified across sites over years. Among those hybrids were two checks, namely Q16 (PAN5Q649R) and Q33 (Phb31MO7BR). The top five high – yielding hybrids selected based on the selection index were considered to be the most productive, stable and adaptable based on the GGE biplot and AMMI stability values. None of these single cross hybrids over yielded the best hybrid check (Q16) in the current study. A high potential environment, Centane, was the ideal environments for evaluating genotypes in the present study. The studies showed inbred lines L22, L23, L26, L28, L25, L29 and L31 to be low N stress tolerant at 0 kg N ha-1 based on the low N stress tolerance indices under glasshouse and the field conditions; they were also among the top ten grain-yielders under field conditions at 0 kg N ha-1. Also, in the NUE study, they were found to be among the top ten most N-efficient inbred lines under low N soils, under 30 kg N ha-1, and were among the top twenty-four inbred lines with high NUE values across the N levels in the study. Inbred lines L29 and L22 also produced testcross hybrids that were among the top twenty based on GY under 0 kg N ha-1. The testcross hybrids produced from these inbred lines were also among the top twenty-five with outstanding SCA effects for GY. These inbred lines were also parental lines of some of the top twenty- five best hybrids selected based on the Smith – Hazel selection index in the PVT study. Inbred lines L22, L23, L26, L28, L25, L29 and L31 can therefore further be evaluated and used as sources of N-tolerance genes in QPM breeding programs. tentatively assigned to M-S bond in the complexes. UV-Vis spectroscopy analysis for the complexes and from primary and secondary ligands are between within the range of 338 – 340 nm. PL studies of the primary ligands with metal complexes indicated emissions at 464 nm, 462 nm, 462 nm for Pb(II) and Sn(II), and Cu(II). The presence of secondary ligands was revealed by the absorption peaks at 455, 456 and 457 nm, exhibiting both the signals and chemical constituents of the respective ligands and their corresponding complexes. The electrochemistry in chapters 3 and 4 reveals that phase angle in the Bode plots changes with frequencies for Sn(II) complexes at 58, 57 and 8 respectively. Bode plots showed remarkable electronics of Cu(II) and Pb(II) complex interfaces. The CV curves exhibit two kinds of redox peaks indicating reduction at the negative potentials and oxidation at the positive potentials. The EIS, electrodes produced Rct for Pb(II), Cu(II) and Sn(II) electrodes in chapter 3. Moreover The EIS revealed that Sn(II) sensitizer displaced a stronger chemical capacitance and improved efficiency which could lead to better electron lifetime yield. The obtained CV exhibited anodic and cathodic peaks for Pb(II), connoting a reduction in Pb2+ and oxidation in Pb2-. Bode plot phase angle displayed Sn(II) and Pb(II) with maxima phase, indicating the presence of time constants of the electrode processes in Bis(N-1,4-Phenyl-N-Morhpo-dithiocarbamato bis(Mo/1,4-PHDTC) complexes. From the results in chapter 4, the XRD patterns exhibited good crystalline nature of CuS as a result of sharp and strong diffraction peaks obtained. There are eight peaks of 2θ angle between 26° and 79° relating to orthorhombic structure of SnS. While PbS has a cubic structure with polycrystalline nature, PbS/HDA and PbS both correspond to their crystalline planes of (200), (111), (220), (311), (222), (400), (331), (420) and (422) affirming to PbS QDs structure. SnS/HDA and SnS photosensitizers displayed eleven peaks between the values of 27.02° to 66.05° for SnS/HDA and 26.03° to 66.04° for SnS, in confirming the orthorhombic structure. SEM analysis revealed hexagonal structure for CuS, while PbS and SnS exhibited mesoporous nanostructures with spherical nanoparticles. HRTEM images indicated spherical nano-particles with particle sizes in the range of 3.14 - 44.39 nm. The outcome of HRTEM analysis revealed crystallite sizes varying as 10.90 – 11.57 nm, 3.14 – 5.95 nm and 14.96 – 44.39 nm for the CuS, PbS and SnS, originated from the primary ligands. HRTEM images originating from the Bis(N-1,4-Phenyl-N-Morhpo-dithiocarbamato bis(Mo/1,4-PHDTC) complexes indicated spherical nano-particles with particle sizes of 3.14 - 44.39 nm. Raman images in chapter 5 revealed the presence of Raman active modes of E2g 66 cm-1 and 304, cm-1 and E1g 627 cm-1 and 706 cm-1 for CuS, the active modes of TO 65 cm-1 and 2LO 626 cm-1 for PbS, active modes of B1g 69 cm-1 for SnS and 266 cm-1 for Ag. From the AFM results in chapter 5, CuS photosensitizer displayed a smooth surface and particle estimated to be 0.50 μm and height profile of 12percent. The PbS photosensitizer exhibited particle size of 1.82 μm and 0.654 μm for PbS/HDA, depicting a regular crystal growth rate. The size distribution of SnS nanoparticle at 357 nm connotes smooth surface and good compactness on the substrate. However, SnS/HDA at 122 nm displayed shape and size of non-symmetrical particles. AFM analysis in chapter 8 revealed good size roughness for CuS film. PbS exhibited particle size of 365 nm and size height of 18percent as the smoothest film, while PbS/HDA revealed 1.22 um size with 9percent size height. The evaluated particle sizes varied as 0.11- 1.18 um for SnS/HDA and 0.054 – 0.54 um for SnS films grown at 360 ℃ with size height of 16.8 and 8.4percent. The I-V efficiency obtained indicated that the CuS exhibited a much better efficiency in the QDSCs with higher Voc and the highest η being 2.85percent compared to CuS/HDA and Cu(II). High JSC of 11 mA/cm has been observed in the PbS/HDA QDSSCs, compared to the PbS and Pb(II) cells. The SnS/HDA exhibited a better performance compared to SnS and Sn(II) sensitizers due to the presence of HDA capping agent. , Thesis (MSc) -- Faculty of Science and Agriculture, 2020
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- Date Issued: 2020-01