Physics (PHY): Recent submissions
Now showing items 81-100 of 671
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Studies on the preparation and semiconductor properties of clad silcon fibres
This thesis is a report of experiments made with a sample and a new approach to fabricating silicon devices in cylindrical configuration by co-drawing of two materials together at high temperatures. The co-drawing of silicon ... -
Design and construction of a pulsed high magnetic field facility and high field magnetoresistance studies in some semiconductors
Negative magnetoresistance at 77?K saturates to a value of 0.04 to 0.06 and shows anisotropic behavior. In this connection, a critical review of the experimental results and the theoretical models of negative magnetoresistance ... -
Spectroscopic Studies of Single Wall Carbon Nanotubes, Semiconducting Nanoparticles and Metallic LaB6
Raman Spectroscopy Studies on Novel Materials Raman spectroscopy is a powerful probe to study vibrational and structural properties of solids. This thesis includes spectroscopic studies of novel materials having interesting ... -
Numerical studies of three dimensional turbulence with polymer additives and two dimentional tubulence thin films
Our study contrasts clearly dissipation-reduction phenomena in homogeneous, isotropic turbulence and drag reduction in wall-bounded flows. In both these cases, the polymers increase the overall viscosity of the solution ... -
Statistical properties of three-dimensional magnetohydrodynamic turbulence
Magnetohydrodynamic (MHD) turbulence remains a challenging physical problem. Different aspects of MHD turbulence are being studied by physicists, engineers, and fluid dynamicists. In this thesis, we concentrate on studies ... -
Two dimensional vortices in the presence of a periodic potential
The major features of the phase diagram obtained from the simulation have been reproduced qualitatively in the density functional study. Of course, the DFT does not capture the continuous nature of the transition, which ... -
Study of electrical conduction in polypyrrole at various doping levels
Electrical Conduction Mechanism in Conjugated Conducting Polymer Polypyrrole In this thesis, the mechanism of electrical conduction in conjugated conducting polymer polypyrrole has been studied in high and low doping limits. ... -
Non-Resonant Radiofrequency responce of the layered high-temperature superconducter Bi2Sr2CaCu2O8
In pristine Bi2212, the electromagnetic coupling determines the C44C_{44}C44? of the stack of 2D vortices as the field increases. In the presence of columnar defects, the 2D vortices in adjacent CuO bilayers are pinned ... -
Studies on capacitive, conductance and interface properties of silicon and silicon carbide mos structures
Study on Conductance and Capacitance of Oxide Layers on Silicon and Silicon Carbide Through measurements on dc and ac conductance and incremental capacitance of oxide layers on silicon (n-type) and silicon carbide (n- and ... -
Hydrogen passivation and photoconductivity in Si/Si1-xGex and Si1-xGex/Ge modulation doped heterostructures
In conclusion, we have shown for the first time that the parallel conduction and other kinds of parasitic contributions to the channel mobility can be reduced effectively by hydrogen passivation, and an enhancement in the ... -
Electronic structure of strongly correlated Systems from Ab-initio and model Hamiltonion approaches
Strong electron–electron interactions profoundly influence the properties of systems such as transition-metal, rare-earth, and actinide-based compounds, giving rise to a variety of exotic phenomena. In recent times, there ... -
Structural and devitrification studies of GeSe and CuAsSe glasses
Main Conclusions from the Present Studies Alternate Methods for Pair Correlation Function The search for alternate methods of obtaining the pair correlation function g(r)g(r)g(r) from the structure factor S(Q)S(Q)S(Q), ... -
Low-frequency variability of compact extragalactic radio sources.
Metre-wavelength flux-density variations in compact extragalactic radio sources on time-scales of several months to a few years indicate brightness temperatures up to 3½ orders of magnitude higher than the inverse Compton ... -
Some studies of conformal field theories on higher genus Riemann surfaces
The CFT in two dimensions is useful to understand critical phenomena of statistical mechanics in two dimensions [1,2]. The study of CFTs on sphere and higher genus Riemann surfaces is important because of the usefulness ... -
Electron Tunneling Studies on Normal and Superconducting oxides
In this final chapter, we shall summarize our important observations and suggest improvements and problems for further investigation. This research has been a learning experience for us as we had no prior experience in the ...