RESUMEN
The solvation behavior of protein is an important factor in protein-based food products. In the present study, the xylitol (XY) - ovalbumin (OVN) interaction in an aqueous solution of different pH conditions is analyzed in two methods. In one method, the thermodynamic parameters Gibbs free energy, free volume, and internal pressure are calculated by using ultrasonic velocity, density, and viscosity in addition the refractive index is also measured. The second method is a theoretical method in which using the Laplace transform technique the diffused amount of protein have been calculated for OVN with and without XY in different pH environment. The addition of XY with OVN makes the system with more free energy and free volume as the internal pressure decreases. This trend shows that preferential interaction occurs between solvent-solute molecules. The diffusivity of OVN is reduced after the addition of XY representing the strength of protein-protein interaction. The effect of pH changes is well reflected in both experimental and theoretical results. The results confirm that acidic pH extremity offers more solvation of OVN compared to alkaline pH extremity.
RESUMEN
In new research growth long after glow material is a potential candidate due to its physical properties, chemical stability and wide application in modern solid-state lightning (LED), display devices, dosimetry and sensors. A cerium doped strontium aluminate phosphor (SrAl2O4:Ce3+) was synthesized by conventional solid-state reaction method. The crystal structure and morphology of phosphors, while doping rare earth metal and lithium metal ion was investigated by using X-ray diffraction, Raman spectroscopy and field emission scanning electron microscopy. Fourier transformed infrared spectrum results of the synthesized phosphor composition conforms the characteristic vibration bands of synthesized phosphor. Surface composition analysis of the prepared samples was examined using X-ray photoelectron spectroscopy. Photoluminescence emission band observed at â¼420 nm, â¼490 nm and â¼610 nm region under the excitation wavelength of 256 nm. Wight light emission was confirmed using the Commission Internationale de L'Eclairage (CIE) chromatic coordinate graph. The correlated colour temperature (CCT) value of 0.5% Ce3+ doped SAO of phosphors was calculated is in the range of 1543 K, which is indicated the synthesized phosphors performance as warm white light source. The obtained phosphor has a high dielectric constant and low loss tangent which is useful to optoelectronic devices.
