Heremba Bailung

By Rakesh Ruchel Khanikar and Heremba Bailung

Cold plasma generated in an open environment with a temperature nearly around room temperature has recently been a topic of great importance. It has unlocked the door of plasma application in a new direction: biomedical applications. Cold atmospheric pressure (CAP) plasma comprises various neutral and charged reactive species, UV radiations, electric current/fields etc., which have several impactful effects on biological matter. Some of the significant biological effects of CAP plasma are inactivation of microorganism, stimulation of cell proliferation and tissue regeneration, destruction of cells by initializing apoptosis etc. Although the detailed mechanism of action of plasma on biomaterials is still not completely understood, some basic principles are known. Studies have indicated that the reactive oxygen species and nitrogen species (ROS, RNS) play a crucial role in the observed biological effects. In this perspective, this chapter first provides a brief discussion on the fundamentals of CAP plasma and its generation methods. Then a discussion on the optical diagnostics methods to characterize the plasma is provided. Optical emission spectroscopy (OES) is used to identify the reactive species and to measure their relative concentration. Other important plasma parameters such as gas temperature, electron/excitation temperature and electron density measurement methods using OES have also been discussed. Then a discussion on the application of CAP plasma in biomedical field is provided. A thorough understanding of biochemical reaction mechanisms involving highly reactive plasma species will further improve and extend CAP plasma technology in biomedical applications.

Part of the book: Plasma Science and Technology

By Palash Jyoti Boruah, Parismita Kalita and Heremba Bailung

This chapter focuses on synthesising nanomaterials using an emerging technology called In-Liquid Plasma, i.e., plasma generation inside a liquid. The generation of various reactive species and energetic electrons in the plasma zone plays a crucial role in synthesising nanomaterials. They act as the reducing agent. Non-requirement of the toxic chemical reducing agents make In-Liquid Plasma an environmentally friendly green approach to fabricate nanomaterials. This method enables the simultaneous synthesis of nanoparticles from the electrode material and liquid precursor, which gains much importance on the single-step synthesis of nanocomposites. Moreover, it gives flexibility in controlling both the physical and chemical parameters, which provide fine-tuning required for the size, shape and composition of nanomaterials.

Part of the book: Plasma Science and Technology

By Yoshiko Bailung and Heremba Bailung

The beauty in the formation of vortices during flow around obstacles in fluid mechanics has fascinated mankind since ages. To beat the curiosity behind such an interesting phenomenon, researchers have been constantly investigating the underlying physics and its application in various areas of science. Examining the behavior of the flow and pattern formations behind an obstacle renders a suitable platform to realize the transition from laminar to turbulence. A dusty plasma system comprising of micron-sized particles acts as a unique and versatile medium to investigate such flow behavior at the most kinetic level. In this perspective, this chapter provides a brief discussion on the fundamentals of dusty plasma and its characteristics. Adding to this, a discussion on the generation of a dusty plasma medium is provided. Then, a unique model of inducing a dusty plasma flow past an obstacle at different velocities, producing counter-rotating symmetric vortices, is discussed. The obstacle in the experiment is a dust void, which is a static structure in a dusty plasma medium. Its generation mechanism is also discussed in the chapter.

Part of the book: Vortex Dynamics