Browsing by Subject "models"
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- ItemOpen AccessDigital Open Textbooks for Development: Collaborative, sustainable models for transformation and student involvement(Digital Open Textbooks for Development, 2022-06) Cox, Glenda; Willmers, MichelleThis is a panel presentation by the Digital Open Textbook for Development (DOT4D) initiative members Dr Glenda Cox and Michelle Willmers at the Siyaphumelela Conference in June 2022.
- ItemOpen AccessDOT4D UCT Open Textbook Conversation: Part 2(Digital Open Textbooks for Development, 2020-12) Cox, Glenda; Willmers, Michelle; Masuku, BiancaIn this presentation, the DOT4D team presents an informal webinar in which it shares insights gained relating to the project’s social justice research focus and the trends emerging in the various open textbook development and publishing processes undertaken by lecturers and students at UCT.
- ItemOpen AccessEstimating aerodynamic roughness over complex surface terrain(2013) Nield, Joanna M; King, James; Wiggs, Giles F S; Leyland, Julian; Bryant, Robert G; Chiverrell, Richard C; Darby, Stephen E; Eckardt, Frank D; Thomas, David S G; Vircavs, Larisa H; Washington, RichardSurface roughness plays a key role in determining aerodynamic roughness length (zo) and shear velocity, both of which are fundamental for determining wind erosion threshold and potential. While Zocan be quantified from wind measurements, large proportions of wind erosion prone surfaces remain too remote for this to be a viable approach. Alternative approaches therefore seek to relate Zoto morphological roughness metrics. However, dust-emitting landscapes typically consist of complex small-scale surface roughness patterns and few metrics exist for these surfaces which can be used to predict Zofor modeling wind erosion potential. In this study terrestrial laser scanning was used to characterize the roughness of typical dust-emitting surfaces (playa and sandar) where element protrusion heights ranged from 1 to 199 mm, over which vertical wind velocity profiles were collected to enable estimation of zo. Our data suggest that, although a reasonable relationship (R2> 0.79) is apparent between 3-D roughness density and Zo, the spacing of morphological elements is far less powerful in explaining variations in Zothan metrics based on surface roughness height (R2 > 0.92). This finding is in juxtaposition to wind erosion models that assume the spacing of larger-scale isolated roughness elements is most important in determining Zo. Rather, our data show that any metric based on element protrusion height has a higher likelihood of successfully predicting Zo. This finding has important implications for the development of wind erosion and dust emission models that seek to predict the efficiency of aeolian processes in remote terrestrial and planetary environments.
- ItemOpen AccessInclusivity, collaboration and student co-creation: Open textbook production models for social justice(Digital Open Textbooks for Development, 2022-03) Cox, Glenda; Masuku, Bianca; Willmers, MichelleThis is a presentation by the DOT4D project for Open Education Week in March 2022
- ItemOpen AccessMadagascar: A pacemaker for the Agulhas Current system?(2006) Penven, P; Lutjeharms, J R E; Florenchie, P[1] Western boundary currents are driven by zonally integrated wind-stress curl over the width of subtropical basins. This cross-basin integration is interrupted in the South Indian Ocean where Madagascar presents a formidable barrier. Nevertheless, a western boundary current has been thought to exist in the Mozambique Channel, the Mozambique Current. Recent observations have however shown that no such current exists and that the flow in the channel instead consists of a train of eddies. Is this western boundary anomaly due to the presence of Madagascar? We have used a primitive equations model to investigate the flow in the South West Indian Ocean as if there were no Madagascar. We show that a normal, continuous western boundary current is then formed that constitutes a continuum with the Agulhas Current. The presence of Madagascar is shown to affect the frequency of inter-ocean exchange events south of Africa.
- ItemOpen AccessOpen textbook authorship, quality assurance and publishing: Social justice models of participatory design, engagement, co-creation and partnership(Digital Open Textbooks for Development, 2022-06) Masuku, Bianca; Cox, GlendaThis is a presentation that was given by the DOT4D team as part of the CHED seminar series in June 2022. The presentation demonstrates how academics at UCT are embarking on open textbook initiatives in response to a largely mutual set of social injustices they witness in their classrooms related to affordable access, curriculum transformation and multilingualism. With a focus on student co-creation and inclusion, it presents models that address social (in)justice in the classroom and explores ways in which institutions can address sustainability in order to support open textbook development activity.
- ItemOpen AccessOpen textbook authorship, quality assurance and publishing: Social justice models of participatory design, engagement, co-creation and partnership(Digital Open Textbooks for Development, 2022-05) Cox, Glenda; Masuku, Bianca; Willmers, MichelleA presentation by the DOT4D project for the OE Global Conference held in Nantes, France on the 23-25 May 2022 on collaborative open textbook development models at UCT.
- ItemOpen AccessOpen Textbook Journeys: Lessons learnt at the University of Cape Town(Digital Open Textbooks for Development, 2022-11) Cox, Glenda; Masuku, BiancaThis is a presentation by members of the Digital Open Textbooks for Development (DOT4D) initiative, Glenda Cox and Bianca Masuku, for the European Network of Open Education Librarians (ENOEL) in November 2022.
- ItemOpen AccessOpen Textbooks for Curriculum Change and Student Co-Creation: Collaborative models of open textbook production and student co-creation (Workshop 2)(Digital Open Textbooks for Development, 2022-09) Cox, Glenda; Willmers, Michelle; Masuku, BiancaThis is the second of two workshop presentations by the Digital Open Textbooks for Development (DOT4D) initiative team as part of the Siyaphumelela Workshop Series in September 2022. This session introduced participants to practical ways in which to initiate open textbook production and engage students in authorship, quality assurance and publishing processes.
- ItemOpen AccessPatterns of stress and strain rate in southern Africa(2006) Bird, Peter; Ben-Avraham, Zvi; Schubert, Gerald; Andreoli, Marco; Viola, GiulioThe southward propagation of the East Africa rift presents an opportunity to study plate boundary formation. We tabulate orientation data which confirm the province of NW-SE directed most compressive horizontal principal stress (Wegener stress anomaly) earlier tentatively attributed to ridge push. We also collect information on stress regime, described by the associated Andersonian fault type(s). We use thin shell finite element models with realistic rheology to test three causes of stress: (1) lateral variations in density moment, (2) resistance of unbroken lithosphere to relative plate rotation, and (3) stress concentration ahead of a crack tip. Models with stress due primarily to variations in density moment are unsuccessful in their predictions (59-73% incorrect regimes; 32-40° azimuth errors). Models in which Africa-Somalia spreading is regulated at realistic rates by remote boundary conditions are more accurate (18-41% incorrect regimes; 25-35° azimuth errors). Treating the East Africa rift as a frictionless crack degrades the fit in either case. Apparently, the Wegener stress anomaly is caused primarily by resistance to the relative rotation between the Somalia and Africa plates. The East Africa rift north of 21°S may be weakened by strain but has residual friction ≥0.1. Greater strength of oceanic lithosphere is likely to cause stress increases, reorientations, and regime changes offshore. The predicted strain rate map has high rates along the rift, curving at 12°S into a western arc through Angola-Namibia-South Africa. Seismic hazard in Namibia may be greater than the instrumental catalog suggests. However, a number of unfit data indicate that these models represent only a first step.
- ItemOpen AccessSustainable, collaborative models of open textbook production for social justice and student co-creation: Open textbooks at the University of Cape Town(Digital Open Textbooks for Development, 2022-09) Masuku, Bianca; Willmers, MichelleThis is a workshop presentation by Digital Open Textbooks for Development (DOT4D) initiative members Michelle Willmers and Bianca Masuku at the SASUF Goes Digital Workshop in September 2022. This interactive session provided an overview of open textbook development approaches, focusing on sustainability and collaboration. The workshop session also drew attention to the capacity building and support required at an institutional level to support this work as part of institutional transformation efforts to address social injustice in higher education. This workshop was organized by the SASUF-funded Open Education for Social Justice initiative and was presented in partnership with collaborators from University West and University of Gothenburg.