Appearance Of Characteristic Peak Research Articles

Detection of domestic wastes in Kurose river using synchronous fluorescence spectroscopy

This study was conducted to determine the applicability of synchronous fluorescence spectroscopy (SFS) in differentiating natural organic matter (NOM) from dissolved organic matter (DOM) derived from domestic wastes and in detecting their presence in Kurose River. Sewage effluent, gray water, water extracts from leaf mold and top soil, respectively, algal culture media, and water samples from different points of the river were analyzed. A laboratory mixing experiment was conducted by combining the leaf mold water extract (LM-NOM) and sewage effluent at different ratios. The SFS of the samples were run at offset value of Δ λ=40 nm (Δ λ= λ em− λ ex). The corrected synchronous fluorescence spectra of LM-NOM and the sewage effluent showed different spectral features. A very intense peak at about 531 nm was observed in the sewage effluent spectrum which was not found in the LM-NOM sample. The mixing of fluorescing organic material in LM-NOM and sewage effluent resulted in the simple addition of their respective spectra. This allows the detection of pollutants in surface waters by the appearance of characteristic peaks of the added wastewater. The corrected spectra of the river water sample from a relatively unpolluted point of Kurose River exhibited a simple spectrum with a single peak while the spectra of those collected downstream showed peaks similar to those found in the sewage effluent and gray water spectra. These results demonstrate the applicability of SFS in detecting the presence of different DOM in surface waters.

Chain effect for the inverse mass ratio of colliding particles in grazing ion–surface interactions

A computer simulation was used to study, in the binary collision approximation, the trajectories, energy and angular distributions of 5–15-keV Kr +, Xe + and Rn + ions scattered from atomic chain ridges on Cu(100) and V(100) surfaces in the 〈110〉 direction with a grazing angle interval 5–25°. It was observed that for the inverse mass ratio of collision partners, i.e. when the incident ion is heavier than target atom, the atomic chain effect manifests itself in a number of features associated with the existence of a limiting scattering angle in a single collision. It has been shown that a specific feature of the atomic row effect for the inverse mass ratio of colliding particles results in the appearance of characteristic peaks in the angular and energy distributions useful for diagnostic purposes.

Kinetics and mechanism of epoxidation of cyclohexene and cyclooctene with potassium hydrogen persulphate catalyzed by aquoethylenediaminetetraacetatoruthenate(III) complex ion in water-dioxane medium

The kinetics of oxygenation of [(EDTA)Ru III(H 2O)] − to [(EDTA)Ru v(O)] − by KHSO 5 was studied spectrophotometrically by following the appearance of characteristic peak of [(EDTA)Ru v(O)] − (ϵ 393 max = 8000) at a fixed pH of 6.0 and ionic strength 0.2 M (NaCiO 4). The time course of subsequent oxygen transfer from [(EDTA)Ru v(O)] − to cyclohexene and cyclooctene was investigated by following the decrease in the characteristic oxo peak at 393 nm as a function of substrate concentration and temperature (30–50 °C) at a constant pH of 6 and ionic strength 0.2 M (NaC1O 4). Activation parameters for both the oxygenation of [(EDTA)Ru III(H 2O)] − to [(EDTA)Ru v(O)] − and oxygen atom transfer from [(EDTA)Ru v(O)] − to cyclohexene and cyclooctene were determined and probable mechanisms for both reactions proposed.