41 research outputs found
Possibilities for long-term shifts in higher education assessment praxis: Reflecting on COVID-19 as a stimulus for change
It is widely recognized that assessment impacts on the process and behavior of learning. In this article, we, as academic staff development professionals in two faculties at a research intensive South African university, explore the assessment challenges, processes and behaviours that emerged in the context of Emergency Remote Teaching and Learning during the Covid 19 pandemic. We argue that an analysis of changes in assessment culture and behaviour point to possibilities for a shift from the pre-Covid-19 dominance of the âassessment of learningâ paradigm, to an orientation of assessment where both âassessment of learningâ and âassessment for learningâ are more equitably balanced, with potentially profound implications for shaping the ways students construct their understandings and succeed academically
Resourcefulness matters: Student patterns for coping with structural and academic challenges
There is general agreement that there are many structural constraints beyond studentsâ control which influence the degree of success that students can attain as they learn to participate in academic practice. Less understood are the patterns of studentsâ experiences of the socio-economic environment of their schooling and university, their views of the enabling and constraining conditions of learning and their perceptions of their agency in overcoming these conditions. The data for our study were collected through a questionnaire survey of 591 Bachelor of Education students across three years of the degree at a South African University. Several patterns of resourcefulness and levels of articulation emerged which reveal complex sets of experiences and strategies as students reflect on adversities and challenges they encountered at school and at university. We argue for an in depth understanding of the nature of student agency which recognises its role in shaping their engagement with material, social, academic and affective challenges
Learning to belong: Navigating liminal spaces between disciplinary and teaching identities
The continuous professional learning of academics as university teachers is a national imperative in South Africa. At our university, a Postgraduate Diploma in Education (Higher Education) was introduced in 2015 with the aim to professionalise university teaching through a formal qualification. Students (i.e., candidates) must transition in two ways: firstly, from being disciplinary specialists to being students again; and secondly, into the community of scholarly teaching in higher education. This article examines the liminality experienced by candidates as they navigate the programme and learn to belong to a new scholarly teaching community. Drawing on empirical data collected from graduates and programme coordinators, the authors track candidatesâ shifting identities and showcase how, though initially turbulent and unsettling, the process of learning to belong to a new teaching identity can be rewarding and enriching. The authors conclude by discussing the conditions required to enable candidates to acquire a strong university-teacher identity
Development of highly porous activated carbon from Jacaranda mimosifolia seed pods for remarkable removal of aqueous-phase ketoprofen
In this work, a high porous activated carbon from Jacaranda mimosifolia was developed and employed for ketoprofen adsorption. After the pyrolysis process at 973.15 K, the material presented cavities with different sizes allocated on the particle surface. The material presented a pH at the point of zero charge of 4.1 with the best adsorption at pH 2. The best adsorbent dosage was 0.72 g Lâ1, corresponding to a removal of 96%. The system reached the adsorption equilibrium after 120 min and was described by the linear driving force model. The isotherms revealed that the adsorption capacity decreased with the temperature and followed the Langmuir model, with a maximum adsorption capacity of 303.9 mg gâ1. This high capacity can be associated with the high surface area (928 m2 gâ1) and pore volume (0.521 cm3 gâ1) values. The thermodynamic values indicated that the adsorption system is spontaneous and exothermic. The enthalpy value indicates that the interactions between the adsorbent and adsorbate are physical. Regeneration tests showed a decreasing percentage of removal of 7.86% after 5 cycles. Finally, the adsorbent showed efficiency when treating a simulated effluent containing drugs and inorganic salts, showing the removal of 71.43%
Utilization of Pacara Earpod tree (Enterolobium contortisilquum) and Ironwood (Caesalpinia leiostachya) seeds as low-cost biosorbents for removal of basic fuchsin
Wastes from the Pacara Earpod tree (Enterolobium contortisilquum) and Ironwood (Caesalpinia leiostachya) seeds were studied as biosorbents for the removal of basic fuchsin from waters. Both biosorbents were prepared and characterized by different analytical methods. The characterization data showed that both materials were mainly composed of lignin, cellulose, and hemicellulose. Both biosorbents exhibited roughened surfaces and surface functional groups such as C-H, C=O, C=C, C-O, C-N, and OH bonds. Furthermore, the XRD pattern shows an amorphous phase with a wide peak from 10 to 30° due to the lignin. In terms of dosage and pH, the use of 1 g Lâ1 and 9.0, respectively, is recommended. The initial concentrations for the biosorption kinetics ranged from 50 to 500 mg Lâ1, where the Pacara ear and the Ironwood reached an adsorption capacity of 145.62 and 100.743 mg gâ1 for the 500 mg Lâ1. The pseudo-second-order was found to be the proper model for describing biosorption of basic fuchsin onto Pacara Earpod tree and Ironwood, respectively. For the isotherm experiments, the maximum experimental biosorption capacity was found to be 166.858 and 110.317 mg gâ1 for the Pacara Earpod and Ironwood for the initial concentration of 500 mg Lâ1 at 328 K. The Langmuir and the TĂłth models were the best for representing the equilibrium curves for the basic fuchsin on the Pacara Earpod and the Ironwood, respectively. Maximum adsorption capacities of 177.084 mg gâ1 and 136.526 mg gâ1 were achieved for the Pacara Earpod tree and Ironwood, respectively. The biosorption process was spontaneous, endothermic, and favorable for both biosorbents. The biosorbents were also applied for coloration removal of simulated textile effluents, reaching 66% and 54% for the Pacara Earpod and Ironwood, respectively. For the final application, the materials were used in fixed-bed biosorption, with an initial concentration of 200 mg Lâ1, reaching breakthrough times of 710 and 415 min, leading to biosorption capacities of the column of 124.5 and 76.5 mg gâ1, for the Pacara Earpod and Ironwood, respectively
Adsorption of ketoprofen and paracetamol and treatment of a synthetic mixture by novel porous carbon derived from Butia capitata endocarp
In this work, endocarp of the species Butia capitata was employed as precursor material to prepare a novel activated carbon with intrinsic properties to remove ketoprofen and paracetamol from water efficiently. The activated carbon presented a predominantly microporous structure, with an average pore diameter of 1.23 nm, a total pore volume of 0.449 cm3 gâ1, and a high specific surface area, 820 m2 gâ1. The adsorption kinetics showed a rapid initial decay for both pharmaceuticals, with the system entering equilibrium after 120 min for ketoprofen and 180 min for paracetamol. The pseudo-second-order model presented the best fit for ketoprofen and the Elovich model for paracetamol. The adsorption equilibrium data show that temperature can increase or decrease the adsorption capacity, being found a maximum adsorption capacity of 108.79 and 100.60 mg gâ1 for the ketoprofen and paracetamol, respectively. The Freundlich and Langmuir models presented the best statistical adjustments for the adsorption of ketoprofen and paracetamol, respectively. The thermodynamic analysis confirmed an endothermic process for ketoprofen (ÎH0 = 11.98 kJ molâ1) and exothermic for paracetamol (ÎH0 = -13.37 kJ molâ1). The recycle tests revealed that the adsorbent has an average decrease for removal percentage of only 1.88 % for ketoprofen and 1.57 % for paracetamol. Estimations costs indicate that the price of 1 kg of activated carbon costs is 2.39 USD at minimum. Last, the material presented a highly efficient adsorptive activity to treat a synthetic mixture containing several pharmaceutical compounds and salts, reaching 84.82% removal
High-performance removal of 2,4-dichlorophenoxyacetic acid herbicide in water using activated carbon derived from Queen palm fruit endocarp (Syagrus romanzoffiana)
In this work, an activated carbon sample with a high adsorptive performance for the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) was prepared from queen palm endocarp (Syagrus romanzoffiana) by pyrolysis process. The activated carbon presented an XRD pattern related to carbon graphite and functional groups such as CâH, CËO, OâH. The material particles presented a highly-porous structure, being beneficial to the adsorption process. The activated carbon showed a remarkable specific surface area of 782 m2 gâ1 and pore volume of 0.441 cm3 gâ1. The solution pH presented a strong influence on the adsorption process, with ideal pH = 2, being the best adsorbent dosage, 0.5 g Lâ1. The correspondent removal percentage was 95.4%. The pseudo-second-order model represented kinetic data, presenting R2 > 0.992 and MSR 0.997) and lowest values of MSR (< 92.04 (mg gâ1)2), indicating a maximum capacity of 367.77 mg gâ1. The thermodynamic study indicated a spontaneous operation, with ÎG0 ranging from â23.2 to â32.6 kJ molâ1 and endothermic process (ÎH0 = 67.30 kJ molâ1), involving physical interactions in the adsorbent/adsorbate system. The adsorbent could be regenerated by NaOH and used 7 times with the same adsorption capacity. Hence, overall, the activated carbon prepared from the JerivĂĄ endocarp corresponds to a promising adsorbent in removing 2,4-D herbicide in wastewater
Green synthesis of carbon nanotubes impregnated with metallic nanoparticles: Characterization and application in glyphosate adsorption
In the present work, multi-walled carbon nanotubes (MWCNTs) were used as support material for the impregnation of metallic nanoparticles (MNPs) produced by green synthesis. The influences of the plant extracts (pomegranate (Punica Granatum), Eucalyptus, and pecan (Carya illinoinensis, leaves), metal species (copper and iron), metallic concentrations, and type of functionalization (OH and COOH) on the characteristics of the obtained materials were studied. The precursor and impregnated MWCNTs were characterized through X-ray diffraction, Fourier transformed infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, point of charge, N2 adsorption/desorption isotherms and, X-ray photoelectron spectroscopy. All the synthesized materials were tested as adsorbents to remove glyphosate (GLY) in an aqueous medium. The MWCNTs were resistant to withstand the synthesis process, preserving its structure and morphological characteristics. The copper and iron on the surface of MWCNTS confirm the successful synthesis and impregnation of the MNPs. The MWCNTs impregnated with high metallic concentrations showed favorable adsorption of GLY. The adsorption capacity and percentage of removal were 21.17 mg gâ1 and 84.08%, respectively, for the MWCNTs impregnated with iron MNPs using the pecan leaves as a reducing agent. The results indicated that an advanced adsorbent for GLY could be obtained by green synthesis, using MWCNTs as precursors and pecan leaves as a reducing agent
"Then you get a teacher" - Guidelines for excellence in teaching
Background: Current literature calls for the explicit teaching to health-science educators of the skills, knowledge and dispositions
that are required for successful teaching in higher education.
Aims: This paper draws on evidence from an Oral Hygiene department at a South African university in order to
illustrate these teaching-competency needs. Insights from the evidence are synthesised with current literature regarding best
teaching practice, in support of an appropriate framework for the development of teaching competencies to health-science
educators.
Description: A qualitative approach, using a case study, was adopted. The cohort comprised fifteen students in the first-year Oral
Hygiene cohort class and the ten educators who taught their programme. Data was collected through semistructured interviews
and open-ended questionnaires. The topics that emerged from the combined analysis of the interviews and the questionnaires
were organised into a grid so that common themes could be identified. Current literature regarding teaching and learning was used
as a framework for interpreting the empirical evidence, from which three categories emerged. The first category included
suggestions from students regarding what to do to teach better. A review of the literature indicates that these competencies can be
effectively learnt from self-help guides. The second category included requests for skills development. Literature review suggests
that these might effectively be learnt from single-event workshops facilitated by more able peers. Responses in the final category
highlighted the need for an underpinning theory of teaching and learning, and signalled the need for a more theoretically
grounded and detailed approach to teacher development.
Conclusion: The framework developed from the empirical study and current literature makes it possible for individual clinical
teachers, and staff developers, to construct teaching-competency development plans that are pertinent to individual teachersâ
needs, relevant and practical, educationally sound, and cost-effective in terms of time and effort