ABSTRACT This work experimentally determines crop water requirements as well as effects of varying irrigation schedules on growth parameters of Celosia Argentea. Irrigation treatments of refilling the soil back to 100%fc, 75%fc and 50%fc were applied to predominant three soil samples from different locations within the South Western part of Nigeria having the same sandy loam textural class. Irrigation application was based on daily maximum crop evapotranspiration. Leaf Area, Number of Leaves...
Abstract A flat-type, 60-egg capacity incubator was designed, constructed and tested. The incubator differs from existing designs in that the cabinet was made from a 3-ply, 4mm thick interior grade plywood to reduce cost and at the same time enhance heat insulation. Also, two domestic kerosene lanterns were provided to supplement heat generation by three 40 W electric bulbs during electricity outages as commonly experienced in Nigeria. When tested with 30 eggs of a commonly sold chicken bre...
ABSTRACT Tuberculous pericarditis is an extra pulmonary form of tuberculosis (TB) which leads to a lifethreatening form of pericardial fibrosis in up to 25% of patients despite anti tuberculous therapy. The mechanisms leading to the fibrotic phenotype following infection are poorly understood. A proof of concept study revealed decreased levels of the antifibrotic N-acetylseryl- aspartyl-lysyl-proline or Ac-SDKP in tuberculous pericardial fluid as compared to control (non infectious) peric...
ABSTRACT Change in land use has a direct effect in catchment hydrologic response. It is caused by human intervention to enhance and diversify their livelihood needs, and at the same time get economic benefits from the land resources. These interventions result in changes in surface runoff, soil erosion and sediment yield among others. If the change in land use is not well managed then it will affect the quantity and quality of water resources as well as production potential of the land. Base...
Abstract Using communication signals for radar applications has been a major area of research in radar engineering. In the recent years, due to the widely available wireless signals, a new area of research called commensal radars has emerged. Commensal radars use available wireless Radio Frequency (RF) signals to detect and track targets of interest. This is achieved by placing two antennas, one towards the transmitting base station and the other towards the surveillance area. The signal rece...
Abstract Abdominal aortic aneurysms affect 0.2% of the population and are closely associated with intraluminal thromboses (ILTs) that develop in the sac. Advanced imaging and treatment techniques are available, however there is room for improvement in the methods used to predict the outcome or necessity of surgical intervention. For a computational model to be useful in this clinical setting, it would need to incorporate relevant patient-specific data and prioritise simplicity and speed over...
ABSTRACT The main focus of this study is to evaluate whether load following operation can be performed using the existing South African nuclear power plant. Of which, knowing that will assist in determining whether the addition of load following capabilities on the planned nuclear fleet is justifiable or not. In this report the relevance of Koeberg Nuclear Power Plant to adapt to the demand is examined and the effects on plant operation simulated. The report analyses the operation of the exi...
Abstract Comminution is a critical stage of mineral processing which aims to reduce the size of ore particles through breakage, consequently increasing the likelihood of the liberation of valuable minerals. However, comminution is highly energy-intensive, and an understanding of the key breakage mechanisms has been identified as an important factor in improving the efficiency of the process. Several factors, such as pre-existing cracks, mineralogical composition, ore shape and size are known...
Abstract The Fischer-Tropsch synthesis (FTS) process, better known for its ability to produce synthetic fuel via the hydrogenation of CO, has shown potential to produce valuable chemicals when ammonia is added to the feed. In this work certain aspects of the pathway to the formation of N-containing compounds that form when NH3 is added during FTS, using mostly iron based catalysts is investigated. In addition, the effect this has on the FTS reaction itself is evaluated. To achieve this goal, ...
Abstract This work tests the hypothesis that nanoparticles of 75 at.% platinum (Pt) composition and anisotropic morphology, will outperform standard catalysts in (PEMFC) hydrogen fuel cells. A survey of the scientific literature on this topic is first presented. The synthetic strategies which were developed for the preparation of novel Pt-based binary (bimetallic) and ternary (trimetallic) nanoparticles, containing nickel (Ni), cobalt (Co) and/or vanadium (V), are then described. The synthes...
Abstract The advent of CubeSats has provided a platform for relatively low-budget programmes to realise space missions. In South Africa, Stellenbosch University and the Cape Peninsula University of Technology have impressive space programmes and have been involved in numerous successful satellite launches. A number of CubeSat projects are currently in progress and commercial-grade Attitude Determination and Control Systems (ADCS), and communications modules, are being developed by the respect...
Abstract Active object recognition provides a mechanism for selecting informative viewpoints to complete recognition tasks as quickly and accurately as possible. One can manipulate the position of the camera or the object of interest to obtain more useful information. This approach can improve the computational efficiency of the recognition task by only processing viewpoints selected based on the amount of relevant information they contain. Active object recognition methods are based around h...
Abstract The Microsoft Kinect sensor is a low cost RGB-D sensor. In this dissertation, its calibration is fully investigated and then these parameters are compared to the parameters given by Microsoft and OpenNI. The parameters found were found to be di_erent to those given by Microsoft and OpenNI therefore, every Kinect should be fully calibrated. The transformation from the raw data to a point cloud is also investigated. Then, the Hough transform is presented in its 2-dimensional form. The ...
Abstract The aim of this research was to develop an understanding of and measure the potential for sustainability in a South African urban water context. This was achieved through the use of a systems approach to develop and evaluate a composite index – the Sustainability Index for Integrated Urban Water Management (SIUWM) – based on a vision of what sustainable urban water management means to decision makers at selected local authorities around the country. The vision was expanded into ...
Abstract Within froth flotation, it is widely acknowledged that froth stability affects flotation performance. As a result, it is expected that through the effective management of froth stability, it would be possible to both control and optimise a flotation cell and bank. However, for this to be possible, the relationships between the operating conditions, froth stability behaviour and flotation performance attributes need to be well understood. In addition, froth stability would need to be ...