Universal thermal and electrical transport near the superconductor-metal quantum phase transition in nanowires

We describe the thermal and electrical conductivities of quasi-one dimensional wires, across a quantum phase transition from a superconductor to a metal induced by pairbreaking perturbations. Fluctuation corrections to BCS theory motivate a field theory for quantum criticality. We describe deviations in the Wiedemann-Franz ratio from the Lorenz number, which can act as sensitive tests of the theory. We also describe the crossovers out of the quantum critical region into the metallic and superconducting phases.Comment: 4 pages, 1 figur

HARMONIC MITIGATION AND REACTIVE POWER COMPENSATION USING SHUNT ACTIVE FILTER WITH PI CONTROLLER

Due to the advancement of electrical equipment as most of the load is the nonlinear poor quality of electric supply caused. This paper describes a shunt active filter for power quality improvement. It deals with the problem related to harmonics due to the nonlinear load. The Harmonic current is drawn with the aid of the nonlinear burden from the supply which results in a distortion of the voltage waveform in a supply-side. This distorted voltage and current may make conductors heat up and can lessen the effectiveness and future of the gear. With the goal that the decrease of harmonics is significant in nowadays life.  This filter is utilized to make up for sounds reduced harmonics and receptive power. Three-phase thyristor loads are taken as a nonlinear load. For thyristor 180° scheme is used here. Thyristors are fired for seven different values of firing angle from 0° to 60°. The exhibition of a three-stage shunt dynamic power channel utilizing the instantaneous power hypothesis with a PI controller is clarified in this paper. Simulations are carried out using MATLAB/SIMULINK. simulation results are presented