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In this paper, we have studied the solutions of plane-symmetric Universe with variable ω in the presence and the absence of magnetic field of energy density ρB. A special law of variation for Hubble’s parameter proposed by Bermann in Nuovo Cimento B74, 182 (1983) has been utilized to solve the field equations. Some physical and kinematical properties of the models are also discussed.
Many real-world networks such as the protein–protein interaction networks and metabolic networks often display nontrivial correlations between degrees of vertices connected by edges. Here, we analyse the statistical methods used usually to describe the degree correlation in the networks, and analytically give linear relation in the degree correlation. It provides a simple and interesting perspective...
We study the intensity–intensity correlations of the radiation emitted on probe transition in a three-level cascade electromagnetically-induced transparency (EIT) scheme. Further, we show that by applying even a very weak incoherent pump, the nature of the emitted radiation can be switched from classical to non-classical without significantly affecting the probe transparency.
Two popular methods to analyse the operation of CW CO 2 lasers use the temperature model and the rate equation model. Among the two, the latter model directly calculates the population densities in the various vibrational levels connected with the lasing action, and provides a clearer illustration of the processes involved. Rate equation models used earlier grouped a number of vibration levels together,...
In the present study, we investigated the effect of vacuum annealing on the structural and optical properties of sol–gel dip-coated thin films of Zn0.75Mg0.25O alloy. XRD studies revealed that all these films were polycrystalline with hexagonal wurtzite structure and there was no trace of additional phases other than ZnO. With increase in annealing temperature, the samples showed preferred orientation...
A scintillator-based hodoscope is fully operational at Nuclear Physics Division, Bhabha Atomic Research Centre (NPD-BARC). It was used for characterizing the resistive plate chambers (RPCs) assembled for the RE4 upgrade for the compact muon solenoid (CMS) experiment, installed during the long shut-down (LS1) using cosmic muons. It has now been employed for R & D related to gas mixtures and glass...
The effects of quantum correction on the Rayleigh–Taylor instability (RTI) in stratified plasma layer have been investigated in the presence of suspended particles. A general dispersion relation is obtained from the linearized set of quantum hydrodynamic (QHD) equations. Two particular cases of suspended particle parameters (f∗ and α0) with and without quantum corrections are analysed. The condition...
In this work, the Weibel instability due to inverse bremsstrahlung absorption in laser fusion plasma has been investigated. The stabilization effect due to the coupling of the self-generated magnetic field by Weibel instability with the laser wave field is explicitly showed. The main result obtained in this work is that the inclusion of self-generated magnetic field due to Weibel instability to the...
The parameters of radiofrequency helium discharge under atmospheric pressure were studied by electrical and optical measurements using high voltage probe, current probe and optical emission spectroscopy. Two discharge modes α and γ were observed within certain limits. During α to γ mode transition, a decrease in voltage (280–168 V), current (2.05–1.61 A) and phase angle (76∘–56∘) occurred. The discharge...
This paper presents the results of scattering of 16O+209Bi interaction near the Coulomb barrier. The interaction potential between two nuclei is calculated using the double folding model with the effective nucleon–nucleon (NN) interaction. The calculations of the exchange part of the interaction were assumed to be of finite-range and the density dependence of the NN interaction is accounted for. Also...
In this paper, the famous Klein–Gordon–Zakharov (KGZ) equations are first generalized, and the new special types of KGZ equations with the positive fractional power terms (gKGZE) are presented. In order to derive exact solutions of the new special gKGZE, subsidiary higher-order ordinary differential equations (sub-ODEs) with the positive fractional power terms are introduced, and with the aid of the...
We propose an asymmetrical Mach–Zehnder interferometer (MZI) for efficient pulse generation and compression using porous silicon (PS) waveguide, fibre delay line and couplers. We show a pulse compression of about 0.4 ns at the output port with third-order super-Gaussian input pulse in ∼2 ns time duration and ∼40.3 W peak power level. Also, we show the possibility of obtaining compressed single- or...
We present a numerical investigation on the temperature dependence of gain recovery, of a semiconductor optical amplifier (SOA). It is shown that the decrease in temperature significantly speed-up the gain recovery of the SOA. Under typical operating conditions, a 20 K reduction in temperature of the SOA results in a decrease of 150 ps in the gain recovery time. A comparative estimation of device...
This paper aims to get numerical solutions of one-dimensional KdV equation by Haar wavelet method in which temporal variable is expanded by Taylor series and spatial variables are expanded with Haar wavelets. The performance of the proposed method is measured by four different problems. The obtained numerical results are compared with the exact solutions and numerical results produced by other methods...
A typical device for carrying out sophisticated and complex dusty plasma experiments is designed, fabricated and made operational at the Institute for Plasma Research, India. The device is named as complex plasma experimental device (CPED). The main aim of this multipurpose machine is to study the formation and behaviour of dust vortices in the absence of external magnetic field under the effect of...
The effect of changes in laser-induced stress upon irradiation of monocrystalline silicon was studied in detail using Mach–Zehnder interferometer, high speed camera and computer processing system, real-time detection of stress distribution and stress evolvement under different laser fluences and pulse widths. After irradiation, the changes of interference fringes were used to calculate the stress...
Nanocrystalline Ag-doped indium oxide (AIO) thin films, by employing a much simplified spray pyrolysis technique in different substrate temperatures (300, 350, 400 and 450°C), were fabricated for the first time. The deposited films were subjected to various characterization studies, to explore certain features like the influence of various deposition temperatures on physical and antibacterial properties...
The exact solutions of the field equations with respect to hypersurface-homogeneous Universe filled with perfect fluid in the framework of f(R, T) theory of gravity (Harko et al, Phys. Rev. D84, 024020 (2011)) is derived. The physical behaviour of the cosmological model is studied.
In this paper, we find exact solutions of some nonlinear evolution equations by using generalized tanh–coth method. Three nonlinear models of physical significance, i.e. the Cahn–Hilliard equation, the Allen–Cahn equation and the steady-state equation with a cubic nonlinearity are considered and their exact solutions are obtained. From the general solutions, other well-known results are also derived...
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