Unusually high corrosion resistance in MoxCrNiCo medium entropy alloy enhanced by acidity in aqueous solution

High corrosion resistance of alloys is essential for their structural applications; however, most alloys suffer from degradation of their corrosion resistance with the increasing acidity of their surround-ings. Nonetheless, we developed a series of medium-entropy alloys (MEAs) in this work, which ex-hibit high strength, superior fracture toughness and ultra-high corrosion resistance, outperforming the variety of corrosion resistant alloys hitherto reported. Most interestingly, our MEAs exhibit an unusual anti-corrosion behavior and their corrosion resistance increases with acidity in Cl- containing solutions. Through extensive thermodynamic calculations, density functional theory (DFT) simulations and experi-ments, we reveal that the unusual anti-corrosion behavior of our MEAs can be attributed to their surface chemical complexity, which facilitates the physio-chemical-absorption of H2O and O 2 and thus the rapid formation of metastable medium entropy passive films that contain the lowest amount of defects, as compared to the passive films on conventional alloys reported in the literature.(c) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology

Cooperative Communication Techniques in Wireless-Powered Backscatter Communication:Preambles and Technical Perspective

User cooperation is considered as a key enabling technology in wireless-powered backscatter communication (BaKcom) to improve the energy efficiency of the overall network while comparing to a traditional non-cooperative system. In light of the literature on BaKcom, most researchers consider such scenarios, where they backscatter the information directly to the receiver. The channel fading limits the system throughput between each transmitter and receiver pair. The limitation in system throughput motivates us to provide an introductory guideline and technical perspective of cooperative communication in the backscatter scenario. While this chapter mainly focuses on the technical aspects and potential applications of cooperative BaKcom, a brief historical perspective of cooperation techniques in general for wireless communications along with their implementation details, applications and research challenges is described. Section 2 of this chapter focuses on the role and uses of low powered Internet of Things (IoT) devices in future wireless communications and shows how BaKcom technology benefits such devices. In Section 3, we start our discussion by designing a system model and explaining the basic working of cooperative communication in backscatter scenarios. Based on the available literature, some potential cooperative techniques are provided, along with their comparative analysis. Finally, Section 4 concludes the chapter by providing future research directions