My research interests are in the field of Theoretical Physics, Dielectric relaxation and Theoretical Chemistry in particular:
I am interested in both experimental and theoretical research.
My interests are not limited to the above-mentioned areas and I am eager to pursue new directions and concepts, which are most promising and profitable for today. I am always open to interesting ideas, new collaboration and job opportunities.
Brief summary of my research activities
1) Designing of Microwave components using Finite Element Method :
The study of electromagnetic propagation through various guiding structures and devices has got great significance in development of microwave communication network and technology. However, in physical development of the guiding structures, there is always a possibility of occurrence of certain irregularities in these guiding structures. The main stress of our activities is on Numerical methods and development of programs combining these methods to achieve some objective. Finite Element Method (FEM) is one such procedure, which is useful in different branch of Science and Engineering, for the approximate solution of differential equation. FEM has the main advantage that it can be used for any complicated geometry with irregular shape, and that it is also useful for inhomogeneous and anisotropic media. We have developed our own Finite Element Method Program in Turbo-Basic. The development of FEM involves numerical integration, use of mapping functions, derivative calculation, matrix manipulation like finding eigenvalues and solving set of simultaneous equations. Special storage and evaluation ideas are to be used because large size matrices are involved in process. FEM program developed requires general description of the geometry and material properties. It shows graphically the structure on the screen when needed. It generates the detailed data required for further processing. It automatically divides the structure into elements. For different steps in FEM, separate subroutines are used. The method used for the solution of the eigenvalue equation is Subspace iteration method, which is combination of Jacobi and Strum sequence check method. The developed FEM program has been used to study problems of Electrodynamics for the solution of Maxwell's equations. It involves the study of the effect of discontinuities on electromagnetic propagation through waveguides and resonator. Please see List of Publication
2) Dielectric Relaxation study using Time Domain Reflectometry technique :
Dielectric relaxation spectroscopy probes the interaction of macroscopic sample with a time dependent electric field. The observed dielectric polarization yields information on structural aspects and dynamical processes which is only partly accessible with other methods. The dielectric relaxation behavior of liquid mixtures has gained increasing interest in recent years. For pure liquids and liquid mixtures at ambient temperature, dynamical processes in the time scale of pico-to-nano seconds arise from the orientation of molecular dipole moment, from kinetic processes involved with intermolecular hydrogen bonding. The dielectric properties of solutions have important effect on charge transport, chemical specification and various thermodynamic properties of solutions. An increasing need for dielectric data, characterizing the interaction of materials with microwaves also arises from emerging technical applications such as heating, moisture sensors and process control. We have used the Time Domain Reflectometry (TDR) to find the dielectric properties such as static permittivity, permittivity at high frequency and relaxation time, of binary and ternary mixtures of polar liquids, with the help of a storage oscilloscope having GPIB interfacing card. This time domain data is converted in frequency domain using Fourier transformation, which in turn, is used to calculate reflection coefficient. Finally, by using Least-squares fit method the dielectric parameters are obtained with assumption of different models such as Debye, Havriliak-Nigami model, Cole-Davidson, Cole-Cole etc. Using these values other parameters such as excess permittivity, excess inverse relaxation time, Kirkwood correlation factor, Bruggeman factor, Thermodynamic parameters are also obtained. The computer programs are developed in TURBO-BASIC for the Time Domain Reflectometry (TDR) experiment.
Please see List of Publication.
3) Computer simulation of catalytic reactions :
Heterogeneous catalysis is a field of considerable interest for its practical application. In all heterogeneous chemistry systems, the geometry and structure of the environment in which the chemical process takes place plays a key role in determining the reaction rate and its performance. One of the most challenging problems in surface science is the understanding of the effect of surface roughness on many physical, chemical and biological processes taking place at the interfaces. The study consequently is of great interest for many practical purposes. We have analyzed the catalytic surface reaction over rough surfaces generated by Random deposition and Random deposition with surface diffusion model. The Multifractal scaling analysis has been used for the analysis of reaction probability distribution (RPD) and RPD are transferred into a useful compact form through the multifractal formalism namely through the t(q) and f(a) plots. We have also analyzed catalytic surface reactions over fractal surface of diffusion-limited aggregation and applied dynamic scaling theory to explore the time-dependent effect involved in these reactions over fractal surface. Catalytic surface reactions, by Langmuir-Hinshelwood mechanism, are also analyzed over rough surfaces. The effect of surface roughness on coverage of the reacting species and production rate is studied. The computer programs necessary for these studies are developed in VISUAL FORTRAN.
4) Computational Chemistry
Hydrogen bonding is a topic of considerable interest in physics, chemistry and biology. The strong intermolecular interaction through hydrogen bonds in molecular liquids results in a peculiar dynamical property. The structures of hydrogen-bonded liquids are complicated due to molecular clusters and network structures through hydrogen bonds. Hydrogen bonding has a considerable effect on the microscopic as well as the macroscopic properties of fluid and plays a fundamental role in the understanding and designing of process of biological and environmental importance. Knowledge of the conformation and interactions of amino acids in water is important for the ultimate understanding of protein hydration and the role of water in biological systems. We have studied hydrogen-bonding interactions in organic solvent-water and amino acids-water complexes using ab initio and density functional theory (DFT) methods. Further, the binding energies, dipole-dipole interaction are calculated using the optimized geometries for these complexes. Effect of different basis sets is also studied and the Basis set Superposition errors are calculated for these complexes. We are also interested in Many body interaction and solvent effect in biomolecules. We have used Gaussian 98 for these studies.
I have many other research plans and, of course, I am eager to pursue new directions and concepts, which can be most profitable for today. I am always open for fruitful co-operation with different research groups. If you are interested in my research expertise, we can succeed together!