Ortho effects in organic molecules on electron impact: 21—Oxygen transfers from the ortho nitro group to sulphur in N-aryl-2-nitrobenzenesulphenamides and phenyl-2-nitrophenyl disulphide

Fragment ions arising as a result of oxygen transfers from the nitro group to sulphur have been noticed in N-aryl-2-nitrobenzenesulpbenamides and phenyl-2-nitrophenyl disulphide. In the case of the former a double oxygen transfer to the sulphur has been noticed in the molecular ion whilst a single oxygen transfer to the β-sulphur atom and a double oxygen transfer to the α-sulphur atom have been observed in the latter. The proposed fragmentations are confirmed by high-resolution data, B/E linked-scan spectra and chemical substitution.     

Anomalous dielectric relaxation of water molecules at the surface of an aqueous micelle

Dielectric relaxation of aqueous solutions of micelles, proteins, and many complex systems shows an anomalous dispersion at frequencies intermediate between those corresponding to the rotational motion of bulk water and that of the organized assembly or macromolecule. The precise origin of this anomalous dispersion is not well-understood. In this work we employ large scale atomistic molecular dynamics simulations to investigate the dielectric relaxation (DR) of water molecules in an aqueous micellar solution of cesium pentadecafluorooctanoate. The simulations clearly show the presence of a slow component in the moment-moment time correlation function [PhiMW(t)] of water molecules, with a time constant of about 40 ps, in contrast to only 9 ps for bulk water. Interestingly, the orientational time correlation function [Cmu(t)] of individual water molecules at the surface exhibits a component with a time constant of about 19 ps. We show that these two time constants can be related by the well-known micro-macrorelations of statistical mechanics. In addition, the reorientation of surface water molecules exhibits a very slow component that decays with a time constant of about 500 ps. An analysis of hydrogen bond lifetime and of the rotational relaxation in the coordinate frame fixed on the micellar body seems to suggest that the 500 ps component owes its origin to the existence of an extended hydrogen bond network of water molecules at the surface. However, this ultraslow component is not found in the total moment-moment time correlation function of water molecules in the solution. The slow DR of hydration water is found to be well correlated with the slow solvation dynamics of cesium ions at the water-micelle interface.     

FBG Sensor technology to interfacial strain measurement in cfrp-strengthened concrete beam

Experimental Techniques - Fiber-reinforced polymer (FRP) composite materials are very attractive for use in strengthening of civil engineering structures because of their high strength to weight...     

Extraction of indium,cadmium and thallium by dinonylnaphthalene sulfonic acid

The extraction of indium, cadmium and thallium by dinonylnaphthalene sulfonic acid (HD) from acid media has been studied. HD extracts the metal ion by an ion exchange mechanism. The nature of the species and the extent of aggregation has been evaluated. The effect of diluents on the extraction has also been studied and the results interpreted on the basis of aggregation of HD. A comparative study with solid ion exchangers has also been made.     

Study of mixed complexes by polarography—copper-glycine-α-alanine and cadmium-ammonia-pyridine complexes

The method of DeFord and Hume for the study of complexes by polarography has been extended to the study of mixed complexes of copper-glycine-α-alanine and cadmium-ammonia-pyridine.     

Solvent extraction studies of indium

Solvent extraction of indium from malonic acid medium by Primene JM-T has been studied. The extraction has been studied as a function of pH and concentrations of malonic acid and sodium malonate. The nature of the acid-amine complex has been established by chemical analysis and by the application of the method of Hogfeldt and Fredlund. The equilibrium constant for the reaction has also been calculated. The nature of the indium complexes getting extracted has also been discussed.     

Study of indium complexes by solvent extraction and ion exchange

Complexes of indium with hydroxy carboxylic acids like glycollic, mandelic and thioglycollic acids have been investigated by the method of competitive reactions using HTTA as the auxiliary ligand. An ion exchange study has been made in some cases to confirm the results. An ion exchange study of indium fluoride complexes has also been made. The data have been analysed for the stability constants of the indium complexes.