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Papers by Noor Firas
American Journal of Engineering and Applied Sciences, 2009
The aim of this research was to study the effect of Sr substitution on structure and thermal diff... more The aim of this research was to study the effect of Sr substitution on structure and thermal diffusivity of Ba l-x Sr x TiO 3 ceramic at room temperature. Approach: Structural and thermal diffusivity of Ba 1-x Sr x TiO 3 were studied by performing X-ray diffraction and photoflash measurements. The effects of Sr substitution on the structure and on the thermal diffusivity of Ba 1-x Sr x TiO 3 (0≤x≤1) were investigated. All samples were prepared by standard solid state reaction technique. Results: The results showed that by substituting of Ba 2+ ion with the Sr 2+ the crystallite size decreased. The effect made the thermal diffusivity of Ba 1-x Sr x TiO 3 decreased from 11.30×10 −3 cm 2 sec −1 (for BaTiO 3) to 6.467×10 −3 cm 2 sec −1 (for SrTiO 3) as x varied from 0-1. Conclusion: This study showed a significant effect of structure on thermo-physical property of materials.
American Journal of Engineering and Applied Sciences, 2008
Thermal effusivity of virgin coconut oil-methanol mixtures were measured using open photoacoustic... more Thermal effusivity of virgin coconut oil-methanol mixtures were measured using open photoacoustic cell technique. The samples were prepared by simply mixing virgin coconut oil and methanol using similar procedure applied for preparation of biodisel. Thermal effusivity of the sample was obtained by fitting the experimental data of photoacoustic amplitude signal to the expression of photoacoustic signal as a function of chopping frequency. Thermal effusivity of mixtures decrease between 0.0851 W s 1/2 K −1 cm −2 (pure virgin coconut oil) and 0.0644 W s 1/2 K −1 cm −2 (pure methanol) with the increasing of methanol in the mixture.
American Journal of Engineering and Applied Sciences, 2009
The aim of this research was to study the effect of Sr substitution on structure and thermal diff... more The aim of this research was to study the effect of Sr substitution on structure and thermal diffusivity of Ba l-x Sr x TiO 3 ceramic at room temperature. Approach: Structural and thermal diffusivity of Ba 1-x Sr x TiO 3 were studied by performing X-ray diffraction and photoflash measurements. The effects of Sr substitution on the structure and on the thermal diffusivity of Ba 1-x Sr x TiO 3 (0≤x≤1) were investigated. All samples were prepared by standard solid state reaction technique. Results: The results showed that by substituting of Ba 2+ ion with the Sr 2+ the crystallite size decreased. The effect made the thermal diffusivity of Ba 1-x Sr x TiO 3 decreased from 11.30×10 −3 cm 2 sec −1 (for BaTiO 3) to 6.467×10 −3 cm 2 sec −1 (for SrTiO 3) as x varied from 0-1. Conclusion: This study showed a significant effect of structure on thermo-physical property of materials.
American Journal of Engineering and Applied Sciences, 2008
Thermal effusivity of virgin coconut oil-methanol mixtures were measured using open photoacoustic... more Thermal effusivity of virgin coconut oil-methanol mixtures were measured using open photoacoustic cell technique. The samples were prepared by simply mixing virgin coconut oil and methanol using similar procedure applied for preparation of biodisel. Thermal effusivity of the sample was obtained by fitting the experimental data of photoacoustic amplitude signal to the expression of photoacoustic signal as a function of chopping frequency. Thermal effusivity of mixtures decrease between 0.0851 W s 1/2 K −1 cm −2 (pure virgin coconut oil) and 0.0644 W s 1/2 K −1 cm −2 (pure methanol) with the increasing of methanol in the mixture.