The notion of using the photons emitted from the sun for propulsion in space is not novel. In fact, as early as 1610, Johannes Kepler noticed the potential of this when he pointed out that “comet trails always pointed away from the sun and theorised that the cause may be solar radiation pressure”. Our previous article provided a brief overview and introduction to solar sailing as well as the controlling mechanisms of sailcrafts. In this article, we investigate the deployment of a spinning solar sail with an understanding of both the theoretical dynamics and practical aspects thereof which forms the focus of the original research listed below. The categories of sailcraft: spin and three-axis stabilised Sail structures and deployment Cubesat solar sail 3-axis stabilization using panel translation and magnetic torquing Conclusion
Increased Global emissions resulted in stronger efforts to reduce emissions in order to stabilise the global warming benchmark at 1.5°C. This means that in order to meet the 2030 emissions targets, G20 countries will have to maximise their efforts in 2020 and “and significantly bolster mitigation, adaptation, and finance measures over the next decade”. In light of the above and closer to home, it has been noted that South Africa has the highest emission intensity in the G20 group of industrialised and developing countries. For the country to meet reach its global warming target, it will have to reduce emissions by 32% in the next 10 years. However, the country’s inconsistent contribution is driven by coal-dependent and crisis-riddled national electricity utility, Eskom, which is compromising South Africa’s commitment to slow global warming.
Interest in solar sailing – a revolutionary way to propel spacecraft through space – has piqued in recent years which lead to significant research and resources being contributed to developing it as well as developing similar and supporting technologies. An example of solar sailing in motion is the Planetary Society’s LightSail 2 mission. In this article we cover: A brief introduction to solar sailing The controlling mechanisms of sailcrafts Conclusion
Traditionally, biological visualisation was limited to two-dimensional displays only. Until recently, using three-dimensional displays for quantitative signal assessment, including precise signal selection, processing of multiple signals and determining their spatial relationship to one another has received fairly little attention. However, recent developments in the virtual reality (VR) arena have seen the development and use of lightweight headsets, offering high resolution, low latency head tracking, and a large field of view. These developments and innovation make VR an attractive form of technology to use in biological data visualisation. Biological data visualisation as a branch of bioinformatics entails the application of computer graphics, scientific visualisation, and information visualisation to different areas of the life sciences. Software tools that can be used for visualising biological data include simple, standalone programs and complex, integrated systems. It allows immersive three-dimensional visualisation, compared to a three-dimensional rendering on a two-dimensional display. Since the visualisations are based on a true three-dimensional awareness of the sample, they not only offer a clear representation but also a more intuitive process of interaction which can ultimately aid the scientific investigation and discovery process.
The Department of Electric and Electronic Engineering recently developed a system to sterilise a fluid using only microwaves. This continuous flow system was designed to be used for the sterilisation of biological growth media but would be just as effective for any fluid. The proof of concept design can be further developed into a commercial product for either large scale continuous process lines or as a small lab appliance that can quickly sterilise any size batch of growth media. The concept of sterilisation can also be applied to other fields such as the food industry in order to sterilise milk or fruit juices. A remarkably interesting application would be where this technology is applied to manufacturing lines where water is used to cool down equipment such as saws or drills. In these situations, the unsterilized water can form biofilms within the water pipes which cause blockages and results in the equipment not being cooled properly. If the water is sterilised before it enters the pipes the biofilms will not form, and the equipment will last longer.
The COVID-19 pandemic has brought with it many teaching and learning challenges in higher education. As the lockdown took root, and new rules were ushered in on social distancing, it not only rendered face-to-face teaching impossible but also required of every one of our lecturers and staff members to be supportive and innovative on a daily basis. We knew that above all, we must deliver each academic programme to ensure that the students of our Department can successfully complete their 2020 study year. We are proud that during these unprecedented times with fairly little preparation time, some technological teething problems and COVID-19 undoubtedly testing the commitment of each of us, we have successfully ventured into remote teaching/learning and are currently going full steam ahead with examinations. We know one thing: What we do today will determine how we emerge from the COVID-19 crisis tomorrow. We will soon start gearing up for 2021 admissions and registrations. Watch this space! Finally, Universities should be sensitive to students’ lived realities during this time as well as the pressures placed on them to complete their studies For more information on Stellenbosch University’s student support during the COVID-19 pandemic click here.
REACH is a joint venture between the University of Cambridge and Stellenbosch University in South Africa. With primary funding for hardware and logistics from the Kavli Foundation (through the Kavli Institute for Cosmology in Cambridge) and Stellenbosch University, REACH will be deployed in the Karoo region of South Africa, a unique Radio Frequency Interference (RFI) quiet site that is also home to the Square Kilometer Array telescope. The team has conceived the basics of the proposed system over a period of 2 years and is now in the next phase – construction and the ultimate deployment and operation over the period 2020-2021 (taking into account a probable delay due to the COVID-19 pandemic). The Big Bang model is a theory mapping out the origin and evolution of the Universe and has, over time, become a well-studied field of research. It facilitated a better understanding of the subsequent theory of evolution, over billions of years, of stars and other celestial objects. However, less is known about the period spanning approximately 0.35 to 1 billion years after the assumed Big Bang. According to the theory, during this time, the Universe transitioned from “being a vast volume filled with a cooling neutral gas” to a realm of cosmic objects observable from Earth.
The global demand for energy is rapidly increasing each year. In fact, BP’s Statistical Review of World Energy indicates that “[p]rimary energy consumption grew at a rate of 2.9% … almost double its 10-year average of 1.5% per year, and the fastest since 2010” moving even further away from the accelerated transition envisaged by the Paris climate goals. It has, therefore, become crucial to develop and utilise alternative techniques to meet global energy needs. To facilitate a global energy transition to the clean, sustainable and eco-friendly generation of electricity, the energy sector continuously searches for ways to shift the world to a low-carbon economy; promoting energy-efficient techniques through renewable energy sources for reducing the world’s dependence on fossil fuels. Floating photovoltaic systems, as discussed in this article, are one such technique. We have compiled a table of contents for ease of navigation: Background What are floating photovoltaic systems and how do they work? Conclusion
The current COVID-19 pandemic has sparked a controversial debate around whether radio frequencies such as the latest 5G communication band can be connected to human illness or disease. Most of the claims made online stems from the fact that radio waves are technically radiation. Radiation is more often than not viewed in a negative light without realising that not all radiation is bad and that a distinction should be drawn between ionizing and non-ionizing radiation. Two of the most prevalent questions are: Can viruses be transmitted through electromagnetic energy and can electromagnetic energy transmitted at these frequencies penetrate the human body or alter it in any significant way? In this article, we consider the 5G phenomenon as well as, to our current knowledge, the effect of 5G signals on the human body.
1. Introduction and objectives The ability to accurately forecast energy usage has become progressively more important, especially in the current South African milieu. An interest in energy conservation within today’s energy-conscious society has also grown rapidly. In addition, increased public awareness and political pressure resulted in a universal push to “move away from carbon-emitting energy supplies”. Schools are but one scenario where this has become topical. The problem, however, is that the “current techno-economic sizing of [photovoltaic] PV solutions for schools in South Africa rely on hourly smart meter measurements, costly equipment and scarce skills.” Schools are currently billed on commercial and industrial tariff structures, and by reducing their energy usage and maximum monthly demand, the money saved can be utilised towards improving the quality of education delivered. The recent reductions in PV costs and the convenient concurrence of insolation and schools’ energy usage have piqued interest in enhancing supply with solar PV to save on energy costs and so unburden the grid in developing countries. Furthermore, with the recent advances in PV technology, the costs of the actual solar panels have reduced dramatically. In response, the Department of Electric and Electronic Engineering presented a novel approach to forecast schools’ hourly demand using only monthly utility bills and a trained forecasting model by (1) developing a computationally low-cost, accurate forecasting model using easily accessible input parameters, (2) using the forecast to develop a method capable of adequate load-matching using a solar model, (3) combining the thermal-storage capabilities of EWHs with load-matched solar through smart-scheduling techniques to decrease peak monthly demand and basic energy usages, and (4) providing accurate cost and savings forecasts to determine the viability of the energy-saving intervention at a particular school.
