Papers by Author: M. Sivabharathy

Abstract: In this paper, the application of the photo-acoustic method to study the thermal properties of modified 9Cr-1Mo Steel is described. The photo-acoustic measurements are carried out for the thermal properties of modified 9Cr-1Mo steel samples of various thicknesses. The theoretical basis for quantitative measurements is discussed, together with the advantages and limitations of these methods as compared with conventional measurements.

Abstract: The ornamental granite stone-processing industries of Tamilnadu state produce tons of fine powder wastes during sawing and polishing. It is a non-biodegradable waste that can be easily inhaled by human being and animals and is also harmful to the environment. The main objective of this study is to investigate experimentally the suitability of granite powder (GP) waste as a substitute material for fine/natural aggregate in concrete production. The physical and chemical characterization of the GP waste was also addressed. The experimental parameter was the percentage of granite powder substitution. The cubes and cylinders were prepared using 0%, 5%, 10%, 15%, 20% and 25% of fine/natural aggregate substituted by GP waste. To understand fully the influence of GP waste on the behavior of concrete, several tests such as density, slump cone, split tensile strength, flexural strength; ultra sonic pulse velocity (UPV) and compressive strength tests were performed. The Young’s modulus of elasticity of the concrete was also determined. The GP waste exhibited a very high specific surface value of about 340kg/m2 and chemical analysis results showed that the examined material contains about 77% of silica (SiO2). Experimental results revealed that the rough texture and high specific area of the GP waste significantly decreased the workability of the concrete especially for the substitution level of 20% and 25%. The obtained test results show that the substitution of GP waste up to 15% does not affect the mechanical and fresh concrete properties of the concrete and it was recommended that the replacement of natural sand by GP waste up to 15% of any formulation would be favorable for concrete making.

Abstract: A detailed analysis on the depth profiles of 30 keV H+ ion implanted n-GaAs for various doses from 1014 to 1017 cm-2 was carried by using Secondary ion mass spectrometry (SIMS), to identify the buried amorphous layer. The results are correlated with Raman and XRD strain parameter studies. Various thermal parameters are computed for the 30 keV H+ ion implanted n-GaAs and SIMS study reported for the first time.

Abstract: In this paper, the application of photoacoustic methods to study thermal properties of Al-Li alloy is described. The photoacoustic measurements are carried out for thermal properties on Al-Li alloy and studied for various thicknesses. The theoretical basis for quantitative measurements is discussed together with the advantages and limitations of these methods as compared with conventional measurements. Applications to spectroscopic and depth-profile analysis and also to thermal property measurements in Al-Li samples heat-treated at 755K per hour and annealed at 505K are discussed. The results are compared with literature values, and discussed.

Abstract: Zircaloy-2, an useful nuclear material is studied here by photoacoustics to correlate with the measurements of X-rays. The microstructure variations observed in X-rays could be explained on the basis of thermal diffusivity measured by photoacoustics technique.

Abstract: The nuclear material, Zircaloy-2 is studied here by photoacoustics and the results are correlated with ultrasonic measurements and metallographic microstructures. Precipitation of hard intermetalics and formation of α-martensite, due to thermal aging are also explained through photoacoustic studies.

Abstract: Alloy D9 is a candidate material for core components of fast breeder reactors. This alloy has been 20% cold worked and thermally aged at 1073 K for different time durations and their thermal properties have been studied using photoacoustic (PA) measurements. The results of the PA measurements have been correlated well with the ultrasonic velocity and hardness measurements.