ABSTRACT
In the experiments on redox potential measurement for a series of identical samples of purified and presettled water it was found that the response to ultraviolet irradiation varies appreciably within a few days after treatment, including stepwise changes. In a few hours after exposure, leading to a higher content of reactive oxygen species as compared with the equilibrium values, long-term changes including variations in redox potential and optical system parameters are recorded in water and diluted aqueous media. We propose a heuristic organization model of the water-gas system with an increased content of reactive oxygen species.
Subject(s)
Oxygen/chemistry , Reactive Oxygen Species/chemistry , Water/chemistry , Potentiometry/methods , Solubility , Time FactorsABSTRACT
For investigation of influence of reactive oxygen species on biological systems the peculiarities of light scattering and fluorescence spectra of aqueous solutions in the presence of photoactive additions of acetone (5 x 10(-4) - 30) and anionic probe ANS (5 microg/l-10 mg/l) have been considered. In water and diluted aqueous acetone and ANS solutions, long-term spontaneous variations in parameters of light scattering and fluorescence spectra have been detected. It has been found that the spectral parameters and the character of ANS influence changed drastically at acetone concentrations of approximately 0.1%, approximately (0.2-0.3)%, and approximately 0.8%. The results can be explained by rearrangement of solvent structure in the surrounding of admixture molecules, photochemical processes with the participation of acetone and reactive oxygen species, as well secondary reactions with their involvement in gas-vapor and acetone bubbles.
Subject(s)
Acetone/chemistry , Anilino Naphthalenesulfonates/chemistry , Fluorescent Dyes/chemistry , Ultraviolet Rays , Water/chemistry , Spectrometry, FluorescenceABSTRACT
Surface phonon polariton (SPP) characteristics of In(0.04)Al(0.06)Ga(0.90)N/AlN/Al(2)O(3) heterostructure are investigated by means of p-polarized infrared (IR) attenuated total reflection spectroscopy. Two absorption dips corresponding to In(0.04)Al(0.06)Ga(0.90)N SPP modes are observed. In addition, two prominent dips and one relatively weak and broad dip corresponding to the Al(2)O(3) SPP mode, In(0.04)Al(0.06)Ga(0.90)N/Al(2)O(3) interface mode, and Al(2)O(3) bulk polariton mode, respectively, are clearly seen. No surface mode feature originating from the AlN layer is observed because it is too thin. Overall, the observations are in good agreement with the theoretical predictions.