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Utpal Deka

Publications and source records attributed to Utpal Deka.

3 recordsLinked to original sources

Plasma sheath physics: A circuital description, amelioration, and application

A synoptic review of the electrical circuital model-based analysis of laboratory plasma sheaths, alongside their stability features in a realistic broader horizon, is systematically presented herein. It explains the basic physics responsible for the inductive (L_sh), capacitive (C_sh), and resistive (R_sh) properties simultaneously, exhibited by plasma sheaths. The analyzed model sheath behaviors are judiciously described in the light of the state-of-the-art sheath scenarios, illustratively. The sheath-based circuital components are minutely contrasted with the traditionally available circuital counterparts. The applications of the novel circuital sheath model in widespread fields of research having both fundamental and applied importance are discussed. The main merits of modelling plasma sheaths through the circuital formalism over the existing non-circuital theoretical ones are briefly outlined, jointly with future applied scope.

physics.plasm-ph

Transformative Effect of Oxygen Plasma to Upshot the Structural and Electrical Properties of Pr0.5Sr0.5MnO3 Manganites

A methodical inquiry of the outcome of oxygen plasma exposure in low bandwidth compounds belonging to the perovskite family Pr1-xSrxMnO3 manganites where x = 0.5, has been presented in this communication by comparing the structural and transport properties of the untreated and plasma treated samples. It is witnessed that the high-temperature transmission is carried out by small polarons while the low-temperature transmission is attributed to variable range polarons. The changes in the transport properties may be attributed to the structural modification due to plasma exposure as revealed by the Rietveld analysis of the X-ray diffraction pattern. Further, oxygen plasma exposure boosts the conductivity due to the integration of oxygen ions in the plasma-exposed samples, thereby rendering them oxygen-rich.

cond-mat.mtrl-sci

Stochastic and Vibrational Resonances in a Uni-junction Transistor Relaxation Oscillator

The effects of perturbation of a weak periodic signal (WPS) assisted by noise or a high frequency signal (HFS) respectively on an excitable uni-junction transistor relaxation oscillator (UJT-RO) is presented here. When the perturbation by a WPS modulated with the noise is optimum, the UJT-RO has been observed to produce regular dynamics that mimics the WPS maximum, which is termed as stochastic resonance (SR). Interestingly, when the noise component is replaced by a HFS, the system shows the same SR kind of behavior, which is called vibrational resonance (VR). Here the system produces the dynamics that mimics the WPS resembling the SR assisted by the optimum level of HFS. Both SR and VR have been confirmed through PSPICE simulation. The results show that the regular dynamics that mimics the WPS in case of HFS modulation is better than the noise perturbation.

nlin.AO