Owing to their simplicity and ease of synthesis, carbon nanotubes (CNTs) have captivated attention of researchers. Many engineering applications have investigated the new features of nanostructured carbon nanotubes, such as large surface area, stiffness and durability. CNTs have opened up new opportunities for environmental improvement, pollution management and application in a variety of fields. Multiple types of pollution are produced as a result of population growth, urbanization and industrialization. CNTs are used to solve a variety of challenges, including environmental difficulties, water pollution, biomedical applications, and so on. It becomes an unavoidable present and future material. Different applications of CNTs have been presented in this review paper. CNTs are potential material having number of uses, including water purification, drug delivery, preservatives, catalysis, genetic engineering and artificial implants which are reviewed in this review article. This paper is presenting an explicit and systematic progress of CNTs for water treatment, medicinal uses drug delivery, artificial implants and so on, and a multitude of CNT applications in broad disciplines and their purification methods have been covered. The issues related to synthesis technologies, purification technology, bio-medicinal application and catalytic property of CNTs within the framework of different engineering applications and environmental impact are discussed in this study.

Copper infiltration is demonstrated as a viable solution to achieve higher mechanical properties by filling the interconnected porosities of a ferrous structure with copper infiltrant. This paper will present the results of a design of experiments study based on the selected processing variables in the copper infiltration process. The variables are the following: Infiltrating temperatures, infiltrating time at pre-heat zone and hot zone, the green density of iron part, the migration of copper into the iron part at different processing conditions. The results show the flexibility of the infiltration process to attain certain mechanical properties by changing the processing conditions.

A comparative study is made on root bending fatigue performance of spur gears and plane bending fatigue performance of notched test bars. R = 0 root bending fatigue tests are made on small spur gears with critical root radius 1.0 mm. The results are compared to plane bending fatigue tests of 0.9 mm radius notched specimens. Results are presented for tests on 4%Ni/2%Cu/1.5%Mo prealloyed PM steel with addition of about 0.6% graphite. Predicted values from the test bars coincide well with the results obtained from the gear root fatigue tests.