RESUMO
Magnesium is renowned for its favorable low-density attributes, rendering it a viable choice for commercial engineering applications in which weight has substantial design implications. Magnesium (Mg) stands as a readily obtainable metallic element, exhibiting robustness, efficient heat dissipation, and excellent damping properties. The utilization of pure magnesium remains infrequent due to its susceptibility to instability under high temperatures and pronounced vulnerability to corrosion within humid environments. Hence, the incorporation of magnesium alloys into the design process of aircraft, automotive, and biomedical applications assumes paramount importance. This Review presents a comprehensive review of research endeavors and their resultant achievements concerning the advancement of magnesium alloys. Specifically focusing on aerospace, automotive, and biomedical applications, the Review underscores the pivotal role played by alloying constituents, namely aluminum (Al), copper (Cu), calcium (Ca), and PEO coatings, in influencing the microstructural attributes, mechanical potency, and resistance to corrosion.
RESUMO
Since the invention of the aircraft, there has been a need for better surface design to enhance performance. This thirst has driven many aerodynamicists to develop various types of aerofoils. Most researchers have strongly assumed that smooth surfaces would be more suitable for air transport vehicles. This ideology was shattered into pieces when biomimetics was introduced. Biomimetics emphasized the roughness of a surface instead of smoothness in a fluid flow regime. In this research, the most popular 0012 aerofoils of the National Advisory Committee for Aeronautics (NACA) are considered to improve them, with the help of a surface pattern derived from the biological environment. Original and biomimetic aerofoils were designed in three dimensions with the help of Solidworks software and analyzed in the computational flow domain using the commercial code ANSYS Fluent. The implemented biomimetic rough surface pattern upgraded the NACA 0012 aerofoil design in the transonic flow regime. Lift and viscous forces of the aerofoil improved up to 5.41% and 9.98%, respectively. This research has proved that a surface with a little roughness is better than a smooth surface.
RESUMO
Background: The confidence of Bottom 40 (B40) shareholders is crucial for cooperative's sustenance within wider corporate governance. An in-depth study on cooperatives is needed, as they play a crucial role in the Malaysian economic system and contribute greatly to the country's social development. However, in the current landscape, confidence among shareholders is at stake. This study aims to identify the research gap into corporate governance for cooperativess in relation to B40 shareholder confidence, as well as identify current study challenges and develop a conceptual framework for future research. Methods: We conducted a systematic literature review, with the use of agency theory to assess shareholders' confidence. Emerald, ProQuest, InderScience, Scopus and Science Direct were the online databases used in this study to search five keyword phrases: corporate governance, confidence, cooperative, agency theory and Bottom 40% (B40) household. Tranfield's five stages were used to conduct the systematic review. Results: Only 5 of the 324 studies assess shareholders' confidence in cooperatives, as well as one paper on B40 and two papers on agency theory. Our review presents three major findings. First, research in the context of B40 shareholder's confidence in cooperatives is scarce. Second, the challenges related to shareholders' confidence in B40 are major issues in the context. Third, research on agency theory in the context of shareholders' confidence within cooperatives and corporate governance is still scant. Conclusions: This review urges the research community to conduct more studies based on the highlighted research gaps.