The Single Langmuir Probe under Orbital-Limited Conditions in a Low-Density Collisional Plasma

The cylindrical Langmuir probe under orbital-limited conditions was used to determine the charge density in a low-density collisional plasma. The Langmuir's theory was applied to both electron and ion saturation currents in their respective accelerating regions. Present study indicates that the length of the probe significantly affects the probe characteristics. A probe of suitable length under orbital-limited conditions may be useful under the experimental conditions where the radius of the probe is much smaller than the Debye lengt.

Platinum particles supported on titanium nitride: an efficient electrode material for the oxidation of methanol in alkaline media

In the present study, titanium nitride which shows exceptional stability, extreme corrosion resistance, good electronic conductivity and adhesion behaviour is used to support platinum particles and then used for methanol oxidation in an alkaline medium. The catalyst shows very good CO tolerance for the electrochemical oxidation of methanol. In situ infrared spectroelectrochemical data show the remarkable ability of TiN to decompose water at low over potentials leading to -OH type functional groups on its surface which in turn help in alleviating the carbon monoxide poisoning associated with methanol oxidation. TiN supported catalysts are found to be very good in terms of long term stability, exchange current density and stable currents at low over voltages. Supporting evidence from X-ray photoelectron spectroscopic data and cyclic voltammetry clearly demonstrates the usefulness of TiN supported Pt catalysts for efficient methanol oxidation in alkaline media.

Optical properties of activated reactive evaporated TiO2 films

This paper discusses the optical properties of single-layer TiO2 films deposited using an activated reactive evaporation process. The combined effects of substrate temperature (in the range 70–200 °C) and discharge currents (0–400 mA) on refractive index, extinction coefficient and packing density of these films are investigated. Significant changes in refractive index values have been observed with increases in substrate temperature and discharge current. The change in refractive index is correlated with the variation in packing density. The variation in extinction coefficient was reduced using the combined effects of substrate temperature and discharge currents. A comparison with films deposited in neutral oxygen has also been made.