1,720,992 research outputs found
Surface functionalization of bioactive glasses with natural molecules of biological significance, part I: Gallic Acid as model molecule
No full textSurface functionalization of bioactive glasses with natural molecules of biological significance, part II: Grafting of polyphenols extracted from grape skin
No full textMeasurement of total antioxidant capacity of human plasma: setting and validation of the CUPRAC-BCS method on routine apparatus ADVIA 2400.
No full textWeak alkali and alkaline earth metal complexes of low molecular weight ligands in aqueous solution
No full textThis work is aimed at reviewing the chemical literature dealing with thermodynamic aspects of the weak complex formation (species with log K values less than about 3) between alkali and alkaline earth metal ions with low molecular weight inorganic and organic ligands in aqueous solution. The following ligands (up to hexavalent anions) were examined in detail: (i) hydroxide, chloride, sulfate, carbonate and phosphate as inorganic, and (ii) carboxylates, amines, amino acids, complexones and nucleotides as organic ligands. The paper also identifies the main reasons responsible for the dispersion of the stability data on ion pairs in the literature. When possible, the trend of stability for the different metal ions interacting with the same ligand will be considered to find predictive interaction relationships. Since the stability of weak alkali and alkaline earth metal complexes
are mainly due to electrostatic interaction, simple empirical relationships were obtained between log K and the charge of the anionic ligand. The interest for alkali and alkaline earth cations rises since they are used in study of basic science as components of the supporting electrolyte and are widely diffused in natural fluids. Some examples of application of this science were presented too, to show the role of weak complex formation in the modelling process of natural systems
Optimization of the separation of mono- and dichloroanilines in ion interaction high-performance liquid chromatography
No full textSurface functionalization of bioactive and ferrimagnetic glass-ceramics (SC45) with gallic acid and folic acid
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Combining synchrotron radiation techniques for the analysis of gold coins from the Roman Empire
Get PDFFour gold coins minted in the V century have been studied with non-destructive synchrotron radiation techniques, namely X-Ray Fluorescence (XRF) and X-ray Absorption Near Edge Spectroscopy (XANES). XRF data analyzed coupling standard and statistical methods were used to distinguish the composition of the alloy constituting the coins from that of successive deposits processes. Our analysis presents a quantification of the trace elements present in the metallic alloy providing interesting details for historical insight. Furthermore, on the basis of the XRF maps, some regions of interest were selected for XANES at the K-edge of Fe. Our analysis of the Fe spectra points out two main phases which can be related to Fe oxides naturally present in soil. From the relative abundance of these oxides, information on the site where the coins were found can be obtained, providing additional information on their fate across the centuries
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