Modelling of the effects of renewable energy establishments towards the economic growth of a nation

Renewable energy is one of the current hot topics in the global energy forum and many of the conventional fossil fuelsbased establishments have been replaced with renewable sources over the last few decades. Countries such as China, USA and India have already made huge investments on installing renewable energy infrastructure. Hence, many of these countries are in need of investigating the effects of their investments on the countries’ economic growth, carbon footprint and the well-being of their environment. This study provides a comprehensive discussion on how renewable energy usage can contribute towards the economic enhancements mainly to the Gross Domestic Production (DGP). A conceptual model were established to understand the effects of the development of renewable energy establishments on some key economic performance indicative parameters such as the household consumption, government consumption, capital formation, trade balance and energy import and then eventually on the GDP formation. Then, the data collected from an emerging economy were analysed incorporating a path analysis by using SPSS Amos software. Chi square (χ2) test and maximum likelihood indices are used to assess the overall fit of the model. Overall, the findings of this study clearly show that the promotion of renewable energy establishments can cause a significant reduction in energy related imports while increasing the GDP of a nation. Accordingly, it is apparent that Sri Lanka has aligned their economic strategies in terms of becoming a 100% sustainable energy driven nation by 2050 as their major economic indicators are positively correlated with the promotion of renewable energy establishments

The effect of materials, process settings and screw geometry on energy consumption and melt temperature in single screw extrusion

YesPolymer extrusion is an energy intensive production process and process energy e ciency has become a key concern in the current industry with the pressure of reducing the global carbon footprint. Here, knowledge of the pattern of energy usage and losses of each component in the plant is highly useful in the process energy optimization. Moreover, it is essential to maintain the melt quality while improving the energy e ciency in polymer processing. In this work, an investigation was made on the total energy consumption, drive motor energy consumption, power factor and the melt temperature profile across the die melt flow (as an indication of the melt thermal quality) of an industrial scale extruder with three di erent screw geometries, three polymer types and wide range of processing conditions (altogether 135 di erent processing situations were observed). This aims to widen the knowledge on process energy and thermal behaviors while exploring possible correlation/s between energy demand and melt quality (in terms of melt temperature fluctuations across the melt flow). The results showed that the level and fluctuations of the extruder’s power factor is particularly dependent upon the material being processed. Moreover, it seems that there is a relation between the level of energy demand of the heaters and the level of melt temperature fluctuations. While the extruder specific energy consumption decreases with increasing screw speed, specific energy consumption of the drive motor may have either increasing or decreasing behavior. Overall, this study provides new insights in a wide range on process energy demand and melt thermal quality in polymer extrusion. Moreover, further research is recommended to establish strong correlation/s between process energy consumption and melt thermal quality which should help to enhance process control and hence the product quality in single screw polymer extrusion

Investigating the effects of renewable energy utilization towards the economic growth of Sri Lanka: a structural equation modelling approach

With the rapid depletion of natural resources and increased environmental pollution, nations across the world are in a desperate need of achieving the common goal of sustainable development. Combustion of fossil fuels along with other human activities over the past few decades have resulted in increased greenhouse gas emissions leading to the climate change and the multi-scale pollution of land, air and water that the world is experiencing today. Hence, the focus has now been shifted towards the sustainable and renewable energy sources while prompting a circular economy. Being one of the island nations of South Asia, Sri Lanka has also aligned the country's economic strategies with the global trends and aims to be a 100% sustainable energy dependent nation by 2050. Consequently, there has been a gradual rise in the renewable energy establishments in the country over the past two decades. This study aims to analyze the influence of these establishments on the economic growth of the country, using a structural equation modelling approach. A conceptual model was formulated to represent the relationships between the renewable energy consumption and the key economic indicators, and also a path analysis was carried out to explore the relationships among the variables. The fit of the conceptual model to the secondary data collected related to the economic and energy indicators was established using a number of statistical fit indices such as the Chi-square, absolute fit indices and the root mean square error of approximation. The results indicate that there is no significant direct effect of the renewable energy consumption on the GDP of Sri Lanka yet, but there is an indirect positive effect through capital formation and also an indirect negative effect through trade balance. Hence, it is clear that renewable energy establishments have to be promoted through incentives/policies that lead to capital accumulation via increased renewable energy consumption. Moreover, the analysis and the findings presented in this study can be related and are applicable to many of the emerging economies across the globe

Design, Simulation, Analysis and Optimization of PID and Fuzzy Based Control Systems for a Quadcopter

From MDPI via Jisc Publications RouterHistory: accepted 2021-09-07, pub-electronic 2021-09-10Publication status: PublishedUnmanned aerial vehicles or drones are becoming one of the key machines/tools of the modern world, particularly in military applications. Numerous research works are underway to explore the possibility of using these machines in other applications such as parcel delivery, construction work, hurricane hunting, 3D mapping, protecting wildlife, agricultural activities, search and rescue, etc. Since these machines are unmanned vehicles, their functionality is completely dependent upon the performance of their control system. This paper presents a comprehensive approach for dynamic modeling, control system design, simulation and optimization of a quadcopter. The main objective is to study the behavior of different controllers when the model is working under linear and/or non-linear conditions, and therefore, to define the possible limitations of the controllers. Five different control systems are proposed to improve the control performance, mainly the stability of the system. Additionally, a path simulator was also developed with the intention of describing the vehicle’s movements and hence to detect faults intuitively. The proposed PID and Fuzzy-PD control systems showed promising responses to the tests carried out. The results indicated the limits of the PID controller over non-linear conditions and the effectiveness of the controllers was enhanced by the implementation of a genetic algorithm to autotune the controllers in order to adapt to changing conditions