| || Uncertainties in the Measurements in Differential Scanning Calorimeter and Thermomechanical Analyser
Author : Gayathri, V. ;Kishore, K.
Source : Defence Science Journal ; Vol:31(1) ; 1981 ; pp 63-71
Subject : 536 Thermodynamics
Keywords : TMA ;Youngs modulus ;Isothermal modes;Enthalpy output;Calibration factor
Abstract : Reproducibility of the output signal in Differential Scanning Calorimeter has been examined in detail. The ordinate calibration factor has been found to diminish at higher temperatures. Calibration factor for enthalpy output has also been evaluated. A procedure for calibrating the area by the proper selection of the base-line for both scanning and isothermal modes of operation has been described. This factor has largely been ignored in the papers published so far. And also the assessment of the performance of Thermomechanical analyser has been done by using AI as expansion standard varying heating rate, sensitivity and load. A simple method for the determination Youngs modulus at room temperature using TMA is also given.
| || Orientation Dependence of Elastic Constants for Ice
Author : Parameswaran, V.R.
Source : Defence Science Journal ; Vol:37(3) ; 1987 ; pp 367-375
Subject : 531 Mechanics
Keywords : Classical equations ;Elastic constants;Polycrystal moduli;Shear moduli;Youngs modulus
Abstract : Orientation dependence of Young's and shear moduli of ice single crystals has been calculated at various temperatures using the most up-to-date values of elastic constants and classical equations derived for hexagonal materials. Young's modulus is a maximum whereas shear modulus has a minimum value along the c-axis. Along a direction 50 degree to the c-axis, the shear modulus has a maximum value and the Young's modulus, a minimum. Average values of polycrystal moduli calculated from single crystal values showed only mild temperature dependence.