Teaching and learning in multi-grade classrooms : the LEPO approach

Abstract: The article examines teaching and learning in multi-grade classrooms using the Learning Environment, Learning Processes and Learning Outcomes (LEPO) as a conceptual framework. The article seeks to know how the learning environment is created, how the processes of teaching and learning takes place and how assessment is used to determine the achievement of learning outcomes in multi-grade classrooms. A qualitative research design is used, where interviews were conducted with nine teachers from schools with multi-grade classrooms. Data was analysed thematically. The data revealed the following: the learning environment can be created by grouping learners appropriately in classrooms, creating learning stations and reading stations, proper use of time-tables and adaptation of teaching plans; the learning process should take place through the differentiated curricular approach or quasi-monograde, learners should be afforded the opportunity to learn from their family members, teaching and learning should take place through self-directed learning, peer tutoring and cooperative learning and lessons should cater for different learning styles; to determine the realisation of learning outcomes teachers should assess learners in different grades informally with either the same or grade-specific assessment activities and formally assess with grade-specific assessment tasks. The article also addresses the main criticisms against the LEPO framework by explaining how teachers and learners should interact with the learning environment, learning process and learning outcomes in multi-grade classrooms. I conclude that if the LEPO framework can be implemented in multi-grade classrooms, teaching and learning can be strengthened in such classrooms

Ion beam effects of 26.0 MeV Cu7+ ions in thin metallic and insulating films during heavy ion ERDA measurements

We report on an investigation carried out to determine effects of the probing beam on the structure of typical metallic and insulating thin films during Elastic Recoil Detection Analysis (ERDA) using a heavy ion beam. Metallic niobium nitride (NbN) and insulating calcium fluoride (CaF2) thin films (used as test samples) were irradiated by 26.0 MeV 63Cu7+ ions to fluences of 1.70 1014 ions/cm2 and 2.70 1014 ions/cm2, respectively. The effects of irradiation on the structural properties of the films were studied using Rutherford Backscattering Spectrometry (RBS), X-ray diffraction (XRD) and Atomic Force Microscopy (AFM). RBS results showed a significant (18%) reduction in the thickness of the CaF2 film due to electronic sputtering compared to only 1% reduction in the NbN film. XRD results showed no significant peak shifts in both films, but rather formation of unidentified peaks in the insulating film. AFM results indicated a substantial decrease in the average surface roughness of the insulating film and only a nominal increase in that of the metallic film. Results of electronic sputtering yield measurements carried out by ERDA are explained in terms of both the Coulomb explosion and the inelastic thermal spike models.NECSA, Tshwane University of Technology, University of Pretoria and iThemba LABS Gauteng.http://www.elsevier.com/locate/nimb2016-04-30hb201

Development of an integrated database and data collation system for monitoring and evaluating the public sector antiretroviral treatment (ART) in the Free State province, South Africa

Meeting: 16th International AIDS Conference, Toronto, Canada, August 13 - 18, 2006ISSUES: Paper-based structured clinical records are widely used for monitoring and evaluating the public sector HIV antiretroviral (ART) treatment program in South Africa. Computerized systems are sometimes used for operational data capture but are usually limited to individual clinics and hospitals. Important information also exists in other databases. A requirement exists to collate information into electronic format and integrate data from a variety of sources to facilitate reporting and quality controls. DESCRIPTION: Handheld computers (PDA's) were used to collate data from paper records at urban and rural sites during the first nine months of the ART roll-out program in the Free State province of South Africa. Thereafter a commercial online computer system (Meditech) was implemented. A Microsoft SQL Server 2000 database server was used to deploy the information into a relational and dimensional format using Microsoft Data Transformation Services. External laboratory and resistance data were integrated as well. After 18 months 19013 patients were registered on the system, of which 2743 were ART patients. A total of 143751 forms have been captured with a median of 4 forms/non- ARV patient and 26 forms/ARV patient. Six quality categories with a total of 32 quality routines were implemented. The system has also been used to compile quarterly reports and national indicators. LESSONS LEARNED: PDAs compare favourably with online systems for data collection from remote rural and urban sites and are useful where online systems or connectivity are lacking. Dimensional data modelling and data warehousing techniques are fundamental for creating databases that are optimized for querying, aggregated reporting, longitudinal analysis and research. RECOMMENDATIONS: Data quality remains the most challenging aspect of information systems for monitoring and evaluation. The next phase will be to feed information back to the health care workers and patients to give them the benefit of information systems and to encourage better input data quality

The new Heavy Ion ERDA set up at iThemba LABS Gauteng : multilayer thin film depth profiling using direct calculation and Monte Carlo simulation codes

We report here on the recently built Heavy Ion ERDA set up at iThemba LABS Gauteng; describing a typical application in the study of interfacial reactions in an Al2O3–Ti ceramic–metal multilayer structure annealed in vacuum at 800 C for 2 h. Depth profile extraction was found to be best obtained through combined use of direct calculation and Monte Carlo simulation codes as opposed to using just either of the methods. The obtained profile suggests a case of the Kirkendall effect, whereupon the inter-diffusion between the metal and the ceramic was largely due to the faster diffusion of the metal into the amorphous ceramic than diffusion of the ceramic elements into the metallic layer.National Research Foundation (iThemba LABS) and the International Atomic Energy Agency (IAEA).http://www.elsevier.com/locate/nimbhb201

Effect of Xe ion (167 MeV) irradiation on polycrystalline SiC implanted with Kr and Xe at room temperature

The effect of swift heavy ion (Xe 167 MeV) irradiation on polycrystalline SiC individually implanted with 360 keV Kr and Xe ions at room temperature to fluences of 2×1016 cm-2 and 1×1016 cm-2 respectively, was investigated using transmission electron microscopy (TEM), Raman spectroscopy and Rutherford backscattering spectrometry (RBS). Implanted specimens were each irradiated with 167 MeV Xe+26 ions to a fluence of 8.3×1014 cm-2 at room temperature. It was observed that implantation of 360 keV Kr and Xe ions individually at room temperature amorphized the SiC from the surface up to a depth of 186 and 219 nm respectively. Swift heavy ion (SHI) irradiation reduced the amorphous layer by about 27 nm and 30 nm for the Kr and Xe samples respectively. Interestingly, the reduction in the amorphous layer was accompanied by the appearance of randomly oriented nanocrystals in the former amorphous layers after SHI irradiation in both samples. Previously, no similar nanocrystals were observed after SHI irradiations at electron stopping powers of 33 keV/nm and 20 keV/nm to fluences below 1014 cm-2. Therefore, our results suggest a fluence threshold for the formation of nanocrystals in the initial amorphous SiC after SHI irradiation. Raman results also indicated some annealing of radiation damage after swift heavy ion irradiation and the subsequent formation of small SiC crystals in the amorphous layers. No diffusion of implanted Kr and Xe was observed after swift heavy ion irradiation.National Research Foundation (NRF)http://iopscience.iop.org0022-37272016-10-20hb201

Iodine assisted retainment of implanted silver in 6H-SiC at high temperatures

The effect of high temperature thermal annealing on the retainment and diffusion behaviour of iodine (I) and silver (Ag) both individually and co-implanted into 6H-SiC has been investigated using RBS, RBS-C and heavy ion ERDA (Elastic Recoil Detection Analysis). Iodine and silver ions at 360 keV were both individually and co-implanted into 6H-SiC at room temperature to fluences of the order of 1 1016 cm 2. RBS analyses of the as-implanted samples indicated that implantation of Ag and of I and co-implantation of 131I and 109Ag at room temperature resulted in complete amorphization of 6H-SiC from the surface to a depth of about 290 nm for the co-implanted samples. Annealing at 1500 C for 30 h (also with samples annealed at 1700 C for 5 h) caused diffusion accompanied by some loss of both species at the surface with some iodine remaining in the iodine implanted samples. In the Ag implanted samples, the RBS spectra showed that all the Ag disappeared. SEM images showed different recrystallization behaviour for all three sets of samples, with larger faceted crystals appearing in the SiC samples containing iodine. Heavy Ion ERDA analyses showed that both 109Ag and 131I remained in the co-implanted SiC samples after annealing at 1500 C for 30 h. Therefore, iodine assisted in the retainment of silver in SiC even at high temperature.National Research Foundation (NRF)http://www.elsevier.com/locate/nimbhb201

Effects of Ag and Sr dual ions implanted into SiC

Please read abstract in the article.National Research Foundation of South Africa, Knowledge Interchange and Collaboration Programme (KIC).http://www.elsevier.com/locate/nimbhj2021Physic

The effects of helium, strontium, and silver triple ions implanted into SiC

DATA AVAILABILITY STATEMENT : Data will be made available on request.Please read abstract in the article.https://www.cell.com/heliyonam2024PhysicsSDG-07:Affordable and clean energ