Mapana Journal of Sciences

UV Continuum And Emission Line Variability study of Mrk 841

Bryan Rithesh Miranda, Dr. Vijayakumar H Doddamani, Dr. Vedavathi P — Tue, 28 Sep 2021 00:00:00 +0000

Seyfert galaxies and quasars are the most interesting class of objects among the active galaxies. They exhibit continuum and line flux variability over a long range of wavelengths and time scales. This paper presents the long-term variability study of Mrk 841 using the spectroscopic data obtained by the International Ultraviolet Explorer (IUE) satellite. The IUE”s archival data has been very useful in characterizing the continuum as well as the emission line variability in MRK 841, a nearby bright and variable Seyfert 1 galaxy. We present our results for the first time on long-term and continuum variability in MRK 841from IUE’s final archive. From the Fvar analysis, we have found the UV continuum to vary by 60 % as the highest at 3025 Å with 10 % variability as the lowest at 2225 Å corresponding to the long-term observational period of 1988 - 1993.

THE NONAGENARIAN NEUTRINO

C Sivaram, Kenath Arun, Kiren OV — Tue, 28 Sep 2021 00:00:00 +0000

December 4, 2020 marks 90 years since the concept of neutrinos was proposed as a consequence of the observed discrepancies in several experiments on radioactive decays of various isotopes. There have been great many developments in our understanding of this elusive particle over the past nine decades, also leading to several Nobel Prizes awarded to work on neutrino physics. But there are many aspects of the neutrinos that are still not completely understood, including even its actual rest mass. The neutrino still remains an enigma and we have yet to learn a lot about its different properties. This article summarises the overall picture of the current understanding of the neutrino, right from its inception.

Influence of Heat Generation and Thermal Radiation on MHD Flow in a Vertical Micro-Porous-Channel in the Presence of Viscous Dissipation

Venkateswarlu Malapati, Bhaskar P — Tue, 28 Sep 2021 00:00:00 +0000

This article analysis the influence of heat generation and thermal radiation on steady hydromagnetic fully developed natural convection flow in a vertical micro–porous–channel in presence of viscous dissipation. The governing ordinary differential equations, exhibiting the physics of the flow formation are displayed. Using the relevant non–dimensional variables, the governing equations are transformed into their corresponding non–dimensional form and then solved exactly by employing perturbation technique. The influence of different admissible parameters such as fluid wall interaction parameter, Knudsen number, heat generation parameter, thermal radiation parameter, magnetic parameter, Eckert number and permeability parameter on the fluid velocity, temperature, skin friction coefficient and heat transfer coefficient at the micro–porous–channel surfaces is discussed with the aid of line graphs and tables.

The Development of silane functionalized ZnO nanoparticles for enhancing anticorrosion application

Apoorva S Devadiga, Geetha Mable Pinto Pinto — Tue, 28 Sep 2021 00:00:00 +0000

The effect of zinc oxide nanoparticles surface modified with N-[3-(Trimethoxysilyl)propyl]ethylenediamine (15.5 nm) on mild steel in 0.5M HCl at five different concentrations and temperatures has been studied using Electrochemical Impedance Spectroscopy (EIS) and Tafel polarization curves. Results show that the inhibition efficiency of synthesized mixed type of inhibitor increases up to 40˚C and then decreases because of both physical and chemical adsorption. The activation parameters calculated using Arrhenius plot confirmed chemical adsorption process. Adsorption process follows Langmuir adsorption isotherm and free energy of adsorption values proved the spontaneous adsorption of inhibitor on mild steel sample. Scanning electron microscopy (SEM) analysis also showed that the synthesized nanoparticle is efficient as corrosion inhibitor. Green synthetic method was adopted in synthesis of inhibitor by using Phyllanthus Emblica (Gooseberry) extract. The inhibitor was characterized by Fourier Transform Infra-red Spectroscopy (FT-IR) and X-Ray Diffraction techniques.

Eigenstates of a Charged Simple Harmonic Oscillator in a Uniform Magnetic Field

Dr. Shivalingaswamy T, Kagali B.A — Tue, 28 Sep 2021 00:00:00 +0000

Exact eigenstates of a simple harmonic oscillator and those of a charged particle in a uniform magnetic field are well known and frequently used. In this short article we work out the exact eigenstates of a charged harmonic oscillator placed in a uniform magnetic field using a novel gauge choice for the vector potential.