Aswaghosh Loganathan | Anna University (original) (raw)
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Papers by Aswaghosh Loganathan
Journal of the Taiwan Institute of Chemical Engineers, 2017
Los problemas de desestructuración familiar han registrado un incremento alarmante en España en l... more Los problemas de desestructuración familiar han registrado un incremento alarmante en España en los últimos años. Con frecuencia producen problemas de adaptación tales como reacciones emocionales desadaptativas en los miembros de la familia. El presente trabajo muestra la evaluación e intervención en una adolescente que presenta un problema adaptativo con sintomatología ansiosa y depresiva como consecuencia de un problema de desestructuración familiar. Durante el proceso de evaluación se recogió información con el objetivo de evaluar el problema, y se utilizaron medidas del grado de ansiedad y depresión que indicaron, entre otros síntomas, dificultad para respirar, incapacidad para relajarse y pérdida de interés generalizada. El programa de intervención cognitivo-conductual constó de seis sesiones de 50 minutos desarrolladas durante un mes y medio. Consistió en el entrenamiento de estrategias de regulación de la activación fisiológica, exposición con prevención de respuesta y reestructuración cognitiva. Tras el tratamiento se obtuvo una reducción clínicamente significativa de la sintomatología, si bien persistió cierto grado de pérdida de interés por los demás. Este trabajo muestra la utilidad de realizar intervenciones tempranas breves en los hijos que sufren problemas adaptativos asociados a situaciones de desestructuración familiar.
Journal of the Chinese Chemical Society, 2017
Here we report the effect of microwave treatment on a silica-carbon (SiO 2 /C) filler derived fro... more Here we report the effect of microwave treatment on a silica-carbon (SiO 2 /C) filler derived from rice husk and the function of the microwave-treated filler in an epoxy matrix for electronic packaging applications. Thermogravimetric analysis revealed improved thermal stability of the SiO 2 /C filler upon microwave treatment. X-ray diffraction analysis indicated partial SiC formation after the microwave treatment. For packaging applications, compared to that of the pure epoxy polymer, the thermal conductivity of the epoxy-SiO 2 /C composite was improved by 178% at 40 wt % content of the microwave-treated SiO 2 /C filler. Furthermore, an improvement of 149% in storage modulus and 17.6 C in glass transition temperature of the epoxy-SiO 2 /C composites was realized. The improvement in thermal stability of SiO 2 /C filler could be achieved via a simple microwave treatment, which in turn enhanced the thermal stability, thermal conduction, and thermomechanical strength of the electronic packaging materials.
Materials Letters, 2017
Stabilization of high temperature cubic phase of BaTiO 3 at room temperature is established by ra... more Stabilization of high temperature cubic phase of BaTiO 3 at room temperature is established by rapid quenching of the surfactant assisted sonochemically synthesized BaTiO 3 after calcination for 2 h at 800°C. The quenched BaTiO 3 is stabilized to cubic phase at room temperature in contrast to the BaTiO 3 obtained by normal cooling at a rate of 1°C/min, which exists in the tetragonal phase at room temperature. BaTiO 3 prepared by the same synthetic procedure but two different heat treatment methods possesses almost similar morphology (i.e.) 1dimensional nanorod structure but with different aspect ratio. Quenching prevents the low temperature phase transformation c→t from occurring by providing a narrow window of time in which the reaction is both thermodynamically favourable and kinetically accessible.
Ultrasonics Sonochemistry, 2015
The present study explores the features of tetragonally stabilized polycrystalline zirconia nanop... more The present study explores the features of tetragonally stabilized polycrystalline zirconia nanophosphors prepared by a sonochemistry based synthesis from zirconium oxalate precursor complex. The sonochemically prepared pristine zirconia, 3 mol%, 5 mol% and 8 mol% yttrium doped zirconia nanophosphors were characterized using thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS) and photoluminescence spectroscopy (PL). The reaction mechanism of formation of zirconia nanophosphors is discussed in detail. The probable sonochemical formation mechanism is being proposed. Stabilization of tetragonal phase of pristine zirconia even at room temperature was effectively established by controlling the particle size using ultrasonic waves. Improved phase purity and good surface morphology of the nanophosphors is being achieved via sonochemical route. FE-SEM micrographs reveal that the nanoparticles have uniform spherical shape and size. The narrow particle size distribution (∼15-25 nm) of the zirconia nanoparticles was found from FE-SEM statistical analysis and further confirmed by TEM. Zirconia nanophosphors exhibit a wide energy band gap and which was found to vary with yttrium dopant concentration. The highlight of the present study is the synthesis of novel nanocrystalline ZrO₂ and Y-ZrO₂ phosphor which simultaneously emits extremely sharp as well as intense UV, violet and cyan light on exciting the host atom. The yttrium ion dopant further enhances the photoluminescence property of zirconia. These nanocrystalline phosphors are likely to have remarkable optical applications as light emitting UV-LEDs, UV lasers and multi color displays.
Advanced Optical Materials
Advanced Energy Materials
Journal of the American Ceramic Society
The present study explores the features of tetragonally stabilized polycrystalline zirconia nanop... more The present study explores the features of tetragonally stabilized polycrystalline zirconia nanophosphors
prepared by a sonochemistry based synthesis from zirconium oxalate precursor complex. The sonochemically prepared pristine zirconia, 3 mol%, 5 mol% and 8 mol% yttrium doped zirconia nanophosphors were characterized using thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS) and photoluminescence spectroscopy (PL). The reaction mechanism of formation of zirconia nanophosphors is discussed in detail. The probable sonochemical formation mechanism is being proposed. Stabilization of tetragonal phase of pristine zirconia even at room temperature was effectively established by controlling the particle size using ultrasonic waves. Improved phase purity and good surface morphology of the nanophosphors is being achieved via sonochemical route. FE-SEM micrographs reveal that the nanoparticles have uniform spherical shape and size. The narrow particle size distribution (15–25 nm) of the zirconia
nanoparticles was found from FE-SEM statistical analysis and further confirmed by TEM. Zirconia nanophosphors exhibit a wide energy band gap and which was found to vary with yttrium dopant concentration. The highlight of the present study is the synthesis of novel nanocrystalline ZrO2 and Y-ZrO2
phosphor which simultaneously emits extremely sharp as well as intense UV, violet and cyan light on exciting the host atom. The yttrium ion dopant further enhances the photoluminescence property of zirconia. These nanocrystalline phosphors are likely to have remarkable optical applications as light emitting UV-LEDs, UV lasers and multi color displays.
Journal of the Taiwan Institute of Chemical Engineers, 2017
Los problemas de desestructuración familiar han registrado un incremento alarmante en España en l... more Los problemas de desestructuración familiar han registrado un incremento alarmante en España en los últimos años. Con frecuencia producen problemas de adaptación tales como reacciones emocionales desadaptativas en los miembros de la familia. El presente trabajo muestra la evaluación e intervención en una adolescente que presenta un problema adaptativo con sintomatología ansiosa y depresiva como consecuencia de un problema de desestructuración familiar. Durante el proceso de evaluación se recogió información con el objetivo de evaluar el problema, y se utilizaron medidas del grado de ansiedad y depresión que indicaron, entre otros síntomas, dificultad para respirar, incapacidad para relajarse y pérdida de interés generalizada. El programa de intervención cognitivo-conductual constó de seis sesiones de 50 minutos desarrolladas durante un mes y medio. Consistió en el entrenamiento de estrategias de regulación de la activación fisiológica, exposición con prevención de respuesta y reestructuración cognitiva. Tras el tratamiento se obtuvo una reducción clínicamente significativa de la sintomatología, si bien persistió cierto grado de pérdida de interés por los demás. Este trabajo muestra la utilidad de realizar intervenciones tempranas breves en los hijos que sufren problemas adaptativos asociados a situaciones de desestructuración familiar.
Journal of the Chinese Chemical Society, 2017
Here we report the effect of microwave treatment on a silica-carbon (SiO 2 /C) filler derived fro... more Here we report the effect of microwave treatment on a silica-carbon (SiO 2 /C) filler derived from rice husk and the function of the microwave-treated filler in an epoxy matrix for electronic packaging applications. Thermogravimetric analysis revealed improved thermal stability of the SiO 2 /C filler upon microwave treatment. X-ray diffraction analysis indicated partial SiC formation after the microwave treatment. For packaging applications, compared to that of the pure epoxy polymer, the thermal conductivity of the epoxy-SiO 2 /C composite was improved by 178% at 40 wt % content of the microwave-treated SiO 2 /C filler. Furthermore, an improvement of 149% in storage modulus and 17.6 C in glass transition temperature of the epoxy-SiO 2 /C composites was realized. The improvement in thermal stability of SiO 2 /C filler could be achieved via a simple microwave treatment, which in turn enhanced the thermal stability, thermal conduction, and thermomechanical strength of the electronic packaging materials.
Materials Letters, 2017
Stabilization of high temperature cubic phase of BaTiO 3 at room temperature is established by ra... more Stabilization of high temperature cubic phase of BaTiO 3 at room temperature is established by rapid quenching of the surfactant assisted sonochemically synthesized BaTiO 3 after calcination for 2 h at 800°C. The quenched BaTiO 3 is stabilized to cubic phase at room temperature in contrast to the BaTiO 3 obtained by normal cooling at a rate of 1°C/min, which exists in the tetragonal phase at room temperature. BaTiO 3 prepared by the same synthetic procedure but two different heat treatment methods possesses almost similar morphology (i.e.) 1dimensional nanorod structure but with different aspect ratio. Quenching prevents the low temperature phase transformation c→t from occurring by providing a narrow window of time in which the reaction is both thermodynamically favourable and kinetically accessible.
Ultrasonics Sonochemistry, 2015
The present study explores the features of tetragonally stabilized polycrystalline zirconia nanop... more The present study explores the features of tetragonally stabilized polycrystalline zirconia nanophosphors prepared by a sonochemistry based synthesis from zirconium oxalate precursor complex. The sonochemically prepared pristine zirconia, 3 mol%, 5 mol% and 8 mol% yttrium doped zirconia nanophosphors were characterized using thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS) and photoluminescence spectroscopy (PL). The reaction mechanism of formation of zirconia nanophosphors is discussed in detail. The probable sonochemical formation mechanism is being proposed. Stabilization of tetragonal phase of pristine zirconia even at room temperature was effectively established by controlling the particle size using ultrasonic waves. Improved phase purity and good surface morphology of the nanophosphors is being achieved via sonochemical route. FE-SEM micrographs reveal that the nanoparticles have uniform spherical shape and size. The narrow particle size distribution (∼15-25 nm) of the zirconia nanoparticles was found from FE-SEM statistical analysis and further confirmed by TEM. Zirconia nanophosphors exhibit a wide energy band gap and which was found to vary with yttrium dopant concentration. The highlight of the present study is the synthesis of novel nanocrystalline ZrO₂ and Y-ZrO₂ phosphor which simultaneously emits extremely sharp as well as intense UV, violet and cyan light on exciting the host atom. The yttrium ion dopant further enhances the photoluminescence property of zirconia. These nanocrystalline phosphors are likely to have remarkable optical applications as light emitting UV-LEDs, UV lasers and multi color displays.
Advanced Optical Materials
Advanced Energy Materials
Journal of the American Ceramic Society
The present study explores the features of tetragonally stabilized polycrystalline zirconia nanop... more The present study explores the features of tetragonally stabilized polycrystalline zirconia nanophosphors
prepared by a sonochemistry based synthesis from zirconium oxalate precursor complex. The sonochemically prepared pristine zirconia, 3 mol%, 5 mol% and 8 mol% yttrium doped zirconia nanophosphors were characterized using thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS) and photoluminescence spectroscopy (PL). The reaction mechanism of formation of zirconia nanophosphors is discussed in detail. The probable sonochemical formation mechanism is being proposed. Stabilization of tetragonal phase of pristine zirconia even at room temperature was effectively established by controlling the particle size using ultrasonic waves. Improved phase purity and good surface morphology of the nanophosphors is being achieved via sonochemical route. FE-SEM micrographs reveal that the nanoparticles have uniform spherical shape and size. The narrow particle size distribution (15–25 nm) of the zirconia
nanoparticles was found from FE-SEM statistical analysis and further confirmed by TEM. Zirconia nanophosphors exhibit a wide energy band gap and which was found to vary with yttrium dopant concentration. The highlight of the present study is the synthesis of novel nanocrystalline ZrO2 and Y-ZrO2
phosphor which simultaneously emits extremely sharp as well as intense UV, violet and cyan light on exciting the host atom. The yttrium ion dopant further enhances the photoluminescence property of zirconia. These nanocrystalline phosphors are likely to have remarkable optical applications as light emitting UV-LEDs, UV lasers and multi color displays.