Sharma J.N.,National Institute of Technology Hamirpur |
Singh H.,Lyallpur Khalsa College Jalandhar |
Sharma Y.D.,National Institute of Technology Hamirpur
Multidiscipline Modeling in Materials and Structures | Year: 2011
Purpose The purpose of this paper is to analyze the free vibrations in a stress free and thermally insulated (or isothermal), homogeneous, transversely isotropic, solid cylinder based on three-dimensional coupled thermoelasticity, which is initially undeformed and kept at uniform temperature. Design/methodology/approach The displacement potential functions have been introduced in the equations of motion and heat conduction in order to decouple the purely shear and longitudinal motions. The system of governing partial differential equations is reduced to four second-order coupled ordinary differential equations in radial coordinate by using the method of separation of variables. The matrix Frobenius method of extended power series is employed to obtain the solution of coupled ordinary differential equations along the radial coordinate. The convergence analysis of matrix Frobenius method has been successfully carried out. Findings The purely transverse mode is found to be independent of the rest of the motion and temperature change. The natural frequency, dissipation factor, inverse quality factor and frequency shift of vibrations in a stress free solid cylinder get significantly affected due to thermal variations and thermo-mechanical coupling. Originality/value A new procedure is used and compared to other methods available in the literature. © Copyright - 2011 Emerald Group Publishing Limited. All rights reserved.
Kalia S.B.,Himachal Pradesh University |
Priyanka,P.A. College |
Kaushal G.,Lyallpur Khalsa College Jalandhar |
Lumba K.,P.A. College
Proceedings of the National Academy of Sciences India Section A - Physical Sciences | Year: 2014
The instantaneous formation of green colour obtained on mixing methanolic solutions of thiophanate-methyl (TM) and iron(III) has led to the development of spectrophotometric and potentiometric titration procedures for the determination of thiophanate-methyl—a well known commercial fungicide. Spectrophotometric measurements have been made at λmax = 365 nm. Green colour results from the formation of a complex between disulphide derivative of TM i.e. TMDS (an oxidized product of TM) and iron(II)—a reduced form of iron(III). Potentiometric titrations are marked by an increase in potential with equivalence point at TM to iron(III) ratio of 4:1 (molar ratio). The methods have been successfully adapted to the analysis of commercial fungicide formulations. The proposed methods for the determination of TM are simple, rapid and reliable. © 2014, The National Academy of Sciences, India.