Fabrication and nanoindentation properties of TiN/NiTi thin films and their applications in electrochemical sensing

Nanocrystalline TiN/NiTi thin films have been grown on silicon substrate by dc magnetron sputtering to improve the corrosion and mechanical properties of NiTi based shape memory alloys without sacrificing the phase transformation effect. Interestingly, the preferential orientation of the TiN films was observed to change from (1 1 1) to (2 0 0) with change in nature of sputtering gas from 70% Ar + 30% N₂ to 100% N₂. In present study the influence of crystallographic orientation of TiN on mechanical and corrosion properties of TiN/NiTi thin films was investigated. TiN (2 0 0)/NiTi films were found to exhibit high hardness, high elastic modulus, and thereby better wear resistance as compared to pure NiTi and TiN (1 1 1)/NiTi films. Electrochemical test revealed that TiN coated NiTi film exhibits better corrosion resistance in 1 M NaCl solution as compared to uncoated NiTi film. The application of TiN/NiTi films in the electrochemical sensing of dopamine, which has a critical physiological importance in Parkinson's disease, has been demonstrated. A comparison of voltammetric response of dopamine at silicon based electrodes modified with different nanocrystalline coatings indicated that these films catalyze the oxidation of dopamine.     

A review of the electrical hypothesis of sonoluminescence

The new electrical hypothesis proposed by Degrois and Baldo has been reviewed. The results show that the hypothesis is incompatible with the experimental observations.     

Viscosity of cesium halides,rubidium nitrate,and rubidium lodide in diethyleneglycol and aqueous diethyleneglycol at 25°C

The viscosity of cesium chloride, bromide, and iodide, rubidium nitrate and rubidium iodide in diethyleneglycol, and aqueous diethyleneglycol (20% by weight) at 25°C and at concentrations varying from 0.01 to 0.1M are reported. The results are interpreted in terms of the structure-making/structure-breaking capacity of the electrolyte by estimating theB coefficient of the Jones-Dole equation.     

Torsion units in integral group rings of solvable groups

A weaker version of the Zassenhaus conjecture for torsion units in integral group rings ZG is proved if G is either abelian-by-polycyclic or metabelian. As a consequence we obtain Bovdi's conjecture for torsion units in ZG for metabelian groups     

On the normalizer property for integral group rings

Let R(G) denote the intersection of all nonnormal subgroups of a group G. In this note, we prove that for every finite group G, if R(G) is not trivial, then the normalizer property holds forG.