Ice accretion on rotary-wing unmanned aerial vehicles (RWUAVs) needs to be studied separately from the fixed-wing UAVs because of the additional flow complexities induced by the propeller rotation. The aerodynamics of rotatory wings are extremely challenging compared to the fixed-wing configuration. Atmospheric icing can be considered a hazard that can plague the operation of UAVs, especially in the ...

Wind power is an excellent source of renewable energy in areas with sufficient wind resources. Usually, the best locations for wind turbines are on the tops of hills and ridges, where there are lower temperatures [1]. Cold temperatures are responsible for novel challenges [2, 3]. Due to cold climatic conditions, turbine blades are subjected to icing [4]. A number of methods have been proposed and ...

To avoid the worst impacts of climate change a rapid green energy transition is required where traditional fossil fuels are replaced by low-carbon alternatives. One attractive route to emissions reduction is blue hydrogen, which has lower CO₂ emissions that traditional hydrogen production. For hydrocarbon exporters, increased blue hydrocarbon production can be achieved in two main ways: ...

Inverter-based resources (IBRs), such as solar and wind power are gaining popularity because of their increasing acceptance, environmental benefits and decreasing costs. However, their integration into power systems can lead to significant impacts on system inertia and frequency stability, which are crucial for maintaining the reliability of the power grid. In traditional power systems, the synchronous ...

In recent years, the environmental pollutions at the Three Gorges Dam have become an increasingly concerning issue of the Chinese government. One of the most significant environmental problems is the carbon emissions from the lockage operations at the two ship locks of the Three Gorges Dam. Currently, due to the large amount of vessels passing through the dam, there is always a long queue of vessels ...

This paper presents the benefits of PVA fibers in improving the mechanical properties of class F fly-ash-based geopolymer concrete. The activator used in the geopolymer was 8M sodium hydroxide (NaOH) and sodium silicate (Na₂SiO₃), with a mass ratio of Na₂SiO₃ to NaOH varied from 1.5 to 2.5. Cylindrical specimens with a diameter of 100 mm and a height of ...

The study of the network design problems related to reverse supply chain and reverse logistics is of great interest for both academicians and practitioners due to its important role for a sustainable society. However, reverse logistics network design is a complex decision-making problem that involves several interactive factors and faces many uncertainties. Thus, in order to improve the reverse ...

With the focus on sustainable development, the value recovery from End-of-Life (EOL) and End-of-Use (EOU) products has been given considerable attention by the whole society. Reverse logistics is the process for value recovery and re-creation through a series of activities, i.e., repair, remanufacturing, recycling and energy recovery. However, due to the stochastic reverse product flow, unstable ...

The Zeppelin observatory is a research station near the village Ny-Ålesund in Svalbard. The facility delivers data to international projects devoted to high data quality monitoring of the background air pollution in the Arctic. An approach for quantifying the influence of local and regional pollution on measurements that may be misinterpreted as long-range transported one, is presented here. The ...

This work presents a problem undergoing conjugate heat transfer (CHT). Conjugate heat transfer problems are common is domestic heating/cooling, industrial heat exchangers, cooling of electronics (e.g. PC fans). It is to be noted that in conjugate heat transfer problems, the convection part of the heat transfer is dominated. In the given study, a hypothetical case is built where a heat source (a ...