ABSTRACT
The communication network made the globe a single entity and easily acessible by everyone at any time. Growth in communication networks is unimaginable and advanced nowadays. It is growing every day by means of medium or components used in communication. There are various significant components that are generally used in the communication networks. Specifically, wireless communication (WC) is the dominant in today's communication world. It is supported by the transmitting and receiving nodes at each end of communication. The common components in communication antennas are the transmitters and receivers. It has been unalterable for many decades but their capabilities have been improved through various methods including their manufacturing by the use of alternative materials. This article focuses on metamaterial (MM) based wireless antennas. The growth of metamaterials utilization in the fabrication of microstrip antennas has been discussed comprehensively and its future scope has been envisaged through patent landscape analysis. It is done meticulously using the patent database and in addition, the growth of some of the metamaterials was also predicted using the landscape analysis. Some significant technologies related with metamaterials in WC that were patented have been discussed comprehensively along with the reference to recently published articles. This articles serves as a guide to the researchers working in the communication field to envisage the future advancements.
ABSTRACT
The equimolar High Entropy Alloy (HEA) is incorporated on the surface of SS410 steel to enhance the mechanical properties for the current industrial scenario. The objective of the present work is to make a first attempt at surface modification of SS410 steel with gas atomization synthesized AlCrCoFeNi HEA powder through Friction Stir Processing (FSP). The microhardness and ultimate tensile strength of the FSP-HEA sample are increased by 41.3 % and 39.1 % respectively due to the high degree of refined grains with 2.84 µm and evenly distributed HEA particles. The wear rate of FSP-HEA samples is optimized by response surface methodology with process parameters including applied load, sliding distance, and sliding velocity. The most influential factor and regression model are derived from experimental results that predict the wear rate by the analysis of variance technique. The worn surface of FSP-HEA samples is evaluated by morphological analysis with corresponding induced wear mechanisms. The minimum wear rate is achieved by optimum process parameters along with higher hardness through particle-stimulated nucleation mechanism, Hall-Petch relation, and dynamic recrystallization. The grain refinement, barrier effect, and grain growth hindrance of HEA particles lead to enhancement in the strength of processed HEA samples.
ABSTRACT
Lignocellulosic fiber-reinforced polymer composites are the most extensively used modern-day materials with low density and better specific strength specifically developed to render better physical, mechanical, and thermal properties. Synthetic fiber-reinforced composites face some serious issues like low biodegradability, non-environmentally friendly, and low disposability. Lignocellulosic or natural fiber-reinforced composites, which are developed from various plant-based fibers and animal-based fibers are considered potential substitutes for synthetic fiber composites because they are characterized by lightweight, better biodegradability, and are available at low cost. It is very much essential to study end-of-life (EoL) conditions like biodegradability for the biocomposites which occur commonly after their service life. During biodegradation, the physicochemical arrangement of the natural fibers, the environmental conditions, and the microbial populations, to which the natural fiber composites are exposed, play the most influential factors. The current review focuses on a comprehensive discussion of the standards and assessment methods of biodegradation in aerobic and anaerobic conditions on a laboratory scale. This review is expected to serve the materialists and technologists who work on the EoL behaviour of various materials, particularly in natural fiber-reinforced polymer composites to apply these standards and test methods to various classes of biocomposites for developing sustainable materials.
Subject(s)
Lignin , Plant Structures , Animals , Biodegradation, Environmental , PolymersABSTRACT
Materials research relating to bio-based polymers and composites has become the order of the day and several types of research are being undertaken on these materials. This is mainly due to the belief in the ability of these polymers and composites to serve as potential alternatives for synthetic polymers and fiber-reinforced composites and to mitigate problems pertaining to environmental pollution. A majority of synthetic fibers and polymers in the market today are developed from nonrenewable petroleum-based materials. These have the potential to harm the natural biodiversity of the environment. On the other hand, the use of bioplastics and biocomposites is supported by a few facts such as low cost, lesser energy consumption during production, and notable mechanical and thermal characteristics. The usage of bio-based fibers and polymers in the manufacture of biocomposites in numerous applications greatly enhance the sustainability by eradicating the problem of waste generation. Considering all the above points, the current review focuses on the synthesis and characterization of bioplastics and biocomposites. An elaborate discussion on the mechanical and thermal properties of these materials has also been made. In addition, this review comprehensively discusses the applications, challenges, and prospects of bioplastics and biocomposites.