Sushil Kumar

The significant expansion of connected aerial vehicles – Unmanned Aerial Vehicles (UAVs)/drones – is widened in various areas because of high mobility, dynamic configuration and low maintenance cost of UAVs. The researchers have not fully explored the various research issues in aerial network despite of rapidly increased usage of UAVs in several areas over the last few years. In this context, this chapter presents a comprehensive review on autonomous and connected aerial vehicles such as UAVs/drones in Internet of Things (IoT) environments focusing on research issues-based studies. The issues-based techniques in the aerial environment have been categorically described focusing on their limitations and technical contributions while considering various research metrics. The techniques suggested by researchers have been categorized based on five various issues existing in the research area of connected aerial vehicles. These five issues are named as data collection, computing, routing, security and energy efficiency. Specifically, the significance of autonomous and connected aerial vehicles in IoT environments is highlighted. Following the issues-based taxonomy, a technique-based qualitative review is carried out on various research challenges raised in aerial environments while focusing on main functional components, weaknesses and strengths. The open research challenges related to connected aerial vehicles: UAVs and drones are identified as future research directions in the area.

Africa is full of natural resources but is lacking to fulfil the energy needs of continent due to lack of technology. Nigeria as it seems is situated in the of Africa. with over 210 million population and 768 km² area Nigeria is still struggling to fulfil the electricity requirement of the country, as the data shows 46% of the overall country population is still not connected to grid and most of the electricity generation is being done by non-renewable energy resources which is responsible for pollution in the country. being as a developing nation Nigeria has to find out new possibilities to fulfil the electricity requirement and what is a better way than utilising the resource the entire Africa is known for i.e., sun. solar radiation level of Africa is far more than of the other continents. the research paper consists of the study of six zones of Nigeria and its potential to generate green energy in the country.

WHO and Environment protection agencies have reported that the trending brake pad materials are harmful to human health. These materials (Asbestos and Kevlar) produce toxic gases when used in brake pad composites. It is a cause of lung cancer, mesothelioma, affects the respiratory system, and causes many diseases. It has been causing many million people's death. Kevlar (aramid) is the trending material used in the brake pads. So, it is necessary to find a substitute for these toxic elements. In this direction synthetic fiber has been replaced by natural fiber. The main aim of this study is to find a substitute for asbestos and synthetic fibers (Kevlar) in brake friction material. There are very few comparative studies of Kevlar and natural fiber‐based reinforced polymer composites. In this research Abaca fiber and Kevlar fibers have been reinforced as brake friction material and compared studies. The brake pads were developed by using the various percentages of Abaca fibers (5–20%) and Kevlar fiber (5–10%) with other important ingredients of brake in the hydraulic hind Brake melding Machine. The results of physio‐mechanical properties reveal that % porosity, % water absorption, % compressibility increases as increase the percentage of Abaca fiber and Kevlar fiber in the polymer composite while ash, hardness, and density decrease with an increased percentage of Abaca and Kevlar fiber in the composite matrix. The tensile strength, ultimate compressive strength, impact energy, flexural strength, flexural modulus, tensile modulus shows the best performance for 5% brake pad composites among all Abaca fiber composites and while ultimate shear strength and proof stress show the best performance for 10% brake pad composites among all Abaca mixtures. The Abaca fiber composites with 5 wt% have shown improved results for the coefficient of friction, fade percentage and wear among all‐natural fiber composites while the performance in terms of recovery was observed to increase with an increased percentage of Abaca fiber. In the comparative study it has been found that Kevlar‐based brake pad specimens showed little better results in %‐fade, coefficient of friction, and in wear performance than that of Abaca‐composites while mechanical properties have shown nearby results. The wear rate and thermal stability were recorded highest for 20% Abaca fiber composite and 10% Kevlar composite.