Collaborators: Prof Sebastian Skatulla (University of Cape Town), Prof Ntobeko Ntusi (University of Cape Town), Prof Freedom Gumedze (University of Cape Town, Prof Richard Naidoo (University of Cape Town) and Dr Jagir Hussan (University of Auckland)

Summary: Myocardial tissue is a complex heterogeneous material characterized by different muscle fibre hierarchies interwoven by collagen, elastin, coronary capillaries and various proteins. For instance, fiber orientation, dispersion, thickness, length and relative volume fraction have a considerable local character. The myocardium is a laminated structure with a complex hierarchical organization. These approximately four to six cells thick layers or myocardial sheets are loosely interconnected by perimysial collagen fibers which are able to slide over one another with a relatively low slippage resistance. Moreover, the initially crimped and coiled collagen fibers straighten during passive filling. Another consideration is that for small and intermediate levels of strain the myocardial material response and its stiffness is dominated by kinematics of the myocytes or bundles of myocytes. These are linked to the collagen matrix but remain highly deformable in terms of axial and associated transversal deformation as well as torsional and flexural deformation. See more...

Open

Collaborators: Prof Sebastian Skatulla (University of Cape Town), A/Prof Marcello Vichi (University of Cape Town), Dr Keith MacHutchon (University of Cape Town), Dr Tokoloho Rampai (University of Cape Town), Dr Alfred Bogaers (University of Witwatersrand)}, Prof Joerg Schroeder, Prof Doru Lupascu, Dr Carina Schwarz and Dr Alexander Schwarz (University of Duisburg Essen), Prof Tim Ricken (University of Stuttgart), A/Prof Alessandro Toffoli (University of Melbourne) and Dr Alberto Alberello (University of Tokyo)

Summary: Antarctic sea-ice has a significant impact on the global climate. The seasonal variations in the occurrence of sea-ice controls the exchange between air and sea and consequently influences atmospheric and oceanic circulation. It is therefore important to understand how sea and air temperatures together with the wave dynamics of the ocean impact on the morphology of the ice. Antarctic sea-ice dynamics is poorly understood, because it is significantly different from that in the Arctic where most research efforts have been focused on. Therefore, an interdisciplinary research collaboration has been established between the Department of Civil Engineering and the UCT Departments of Oceanography, Chemical Engineering and Electrical Engineering to combine observations from satellite and deployed buoys, in-situ ice sampling and testing during dedicated expeditions, lab experiments and numerical modelling in an effort to unravel the complex processes in the Antarctic marginal ice zone (Skatulla et al. 2021 https://doi.org/10.5194/tc-2021-209; Marquart et al. 2021 https://doi.org/10.3390/fluids6050176) controlling: (1) the mechanically interaction of sea ice with wind, ocean currents and waves; (2) the wave energy dissipation and scattering as linked to ice type, ice thickness and floe size; and (3) the thermodynamics of ice growth and brine drainage. See more...

Closed

Collaborators: Prof Sebastian Skatulla (University of Cape Town), Prof Ntobeko Ntusi (University of Cape Town), Prof Freedom Gumedze (University of Cape Town, Prof Richard Naidoo (University of Cape Town), Dr Jagir Hussan (University of Auckland)

Summary: The heart is a living structure which can grow stronger, weaker, larger, or smaller within months, weeks, or days as a result of a continuous micro-structural turnover and renewal. In particular, rheumatic heart disease (RHD) is associated with significant ventricular cavity dilation, ultimately leading to heart failure. Modelling is used as one of the research tools to gain basic understanding of the function of the pumping heart in terms of the interaction of electro-physiological, bio-molecular and mechanical processes, under normal and pathological conditions. However, the complexity of computational models results in an exceptionally high demand on computer power. This fact still prevents their application to clinical medicine. This research project aims to develop a computational cardiac mechanics toolbox which facilitates patient-specific modelling of the rheumatic heart making use of the most accurate mathematical description of cardiac function, realistic heterogeneous material composition and highest geometrical detail. In contrast to existing computational models, this approach will match the high degree on accuracy with unparalleled speed and computational efficiency. See more...

Closed

Collaborators: Prof Sebastian Skatulla (University of Cape Town), Prof Hans Beushausen (University of Cape Town), Prof Pilate Moyo (University of Cape Town)

Summary: While it is known that reinforcing steel provides strength and ductility only through bond and anchorage to the concrete, the effectiveness of this connection can be reduced through deterioration of the steel, concrete or both. Therefore, the durability of con-crete structures depends on the resistance of the concrete against chemical and physical factors and its ability to protect the embedded reinforcement against corrosion. In view of the fact that a large number of existing structures are being deteriorated with time by reinforcement corrosion due to environmental exposure, corrosion is one of the main causes for the limited durability of reinforced concrete. The corrosion product, rust, resides at the interface between reinforcement and concrete, degrading the bond be- tween rebar and concrete and thus reducing the service life of the structure. The nonuniformity in bond stress distribution causes difficulties in assessment of the effects of corrosion on bond and thus on the structures. See more...

Closed