Low-frequency phase diagram of irradiated graphene and periodically driven spin-1/2 XYXY chain

We study the Floquet phase diagram of two-dimensional Dirac materials such as graphene and the one-dimensional (1D) spin-1/2 $XY$ model in a transverse field in the presence of periodic time-varying terms in their Hamiltonians in the low drive frequency ($\omega$) regime where standard $1/\omega$ perturbative expansions fail. For graphene, such periodic time dependent terms are generated via the application of external radiation of amplitude $A_0$ and time period $T = 2\pi/\omega$, while for the 1D $XY$ model, they result from a two-rate drive protocol with time-dependent magnetic field and nearest-neighbor couplings between the spins. Using the adiabatic-impulse method, we provide several semi-analytic criteria for the occurrence of changes in the topology of the phase bands of such systems. For irradiated graphene, we point out the role of the symmetries of $H(t)$ and $U$ behind such topology changes. Our analysis reveals that at low frequencies, phase band topology changes may also happen at $t= T/3, 2T/3$ (apart from $t=T$). We chart out the phase diagrams at $t=T/3, 2T/3,\, {\rm and }\, T$ as a function of $A_0$ and $T$ using exact numerics, and compare them with the prediction of the adiabatic-impulse method. We show that several characteristics of these phase diagrams can be analytically understood from results obtained using the adiabatic-impulse method and point out the crucial contribution of the high-symmetry points in the graphene Brillouin zone to these diagrams. Finally we study the 1D $XY$ model with a two-rate driving protocol using the adiabatic-impulse method and exact numerics revealing a phase band crossing at $t=T/2$ and $k=\pi/2$. We also study the anomalous end modes generated by such a drive. We suggest experiments to test our theory.Comment: v1; 26 pages, 19 Fig

Design and Implementation of Soft Switching Boost Converter

The design and implementation of closed loop soft switching boost DC-DC converter have been proposed. The staedy state analysis of open loop converter with operational modes are evaluated. Equations for the design of all the circuit parametrs are attainted and discussed in details for simulation and experimental purpose. The proposed circuit has resonant circuit which has one inductor and two capacitor to achieve soft switching of converter by operating it at zero voltage condition

CARDIOPROTECTIVE EFFECT OF INDIGOFERA TINCTORIA LINN. AGAINST MYOCARDIAL INFARCTION-INDUCED RATS

  Objective: The aim and objective of the present study are to study the protective effects of ethanolic extract of Indica tinctoria (EEIT) in isoproterenol-induced acute myocardial infarction (AMI) in rats.Methods: The effect of two doses of isoproterenol (5 mg/kg and 8.5 mg/kg body weight) changes in aspartate transaminase (AST), alanine transaminase (ALT), lactate dehydrogenase (LDH), creatine phosphokinase (CPK), and total protein (TP) and lipid hydroperoxides, superoxide dismutase (SOD), and glutathione (GSH) in blood serum and heart homogenate, for the two consecutive days (29 and 30), were administered subcutaneously in rats in pre-treatment with EEIT for the 28-day study.Results: There was increased the AST, ALT, LDH, CPK, and lipid peroxides levels and decreased the TP, SOD, GSH with Isoproterenol-induced group. Pre-treatment for 28 days with Indigofera tinctoria significantly (p<0.05) increased antioxidants (SOD , GSH) , TP levels and decreased the cardiotoxic agents significantly (p<0.05) such as LPO, AST, ALT, LDH, and CPK levels in treatment groups.Conclusion: I. tinctoria contains beneficial bioactive photochemicals that have been protective effective against isoproterenol-induced AMI in rats