Electroless plating—A new technique for the preparation of hard tissue specimens for scanning electron microscopy

Specimens with complicated, intricate three-dimensional structures, which are otherwise difficult to coat adequately by conventional means (sputter or evaporative coating) for scanning electron microscopy, can quickly and simply be rendered conductive by electroless plating. The technique can be recommended only when studying specimens at low magnification because fine detail may be lost.     

Optimization of pocket design to produce a thin shape complex profile

In extrusion practice surface quality problems like flow lines with thin and varying thicknesses of complex profiles are experienced. Minimization of temperature variance inside the forming zone and velocity variation across the face of the die are particularly important during the metal flow in order to maintain a good quality finish. Several parameters such as shape, depth of pocket, location of die hole and local bearing lengths can be altered to minimize these effects, but fundamental understanding between these parameters and homogeneity of metal flow are very limited in the literature. This study investigates the influence of above-mentioned parameters on the flow behaviour during extrusion for simple and more complex geometries.     

White light electroluminescence from PSi devices capped with poly(thiophene)(s) as top contact

For the first time, electrochemically deposited poly(3-methylthiophene) and chemically produced poly(3-methylthiophene) and poly(3-phenoxymethylthiophene) have been employed as top electrical contact on porous silicon light-emitting devices. The polymer-capped devices emitted white light as opposed to the uncapped devices, which emitted orange colour. The polymer-capped devices show much higher rectification ratio (up to 1×10⁵) as opposed to 1×10³ for the uncapped devices at ±10 V. The polymer-capped devices show 10³–10⁴-fold improvement in the luminous efficiency over the uncapped devices. Electrochemically deposited poly(3-methylthiophene) top contacts give a luminous efficiency of 8×10⁻⁵ lm W⁻¹ as opposed to 3×10⁻⁹ lm W⁻¹ obtained from uncapped devices. All the devices were found to fit the space charge limited current model.     

Direct electrodeposition of poly(pyrrole) on continuous carbon-loaded microporous membrane films

Ultrasonication helps direct electrodeposition of inherently conducting polymers (ICPs) into the pores of microporous membranes. Use of microporous membranes in conjunction with a partially immersed cylindrical horizontally revolving electrode (PICHRE) permits the production of conducting films on a continuous basis. Production and electrical and mechanical characteristics are described.     

Light emitting devices from organic charge transfer adduct thin films

For the first time, thin film devices of charge transfer adducts of tetrathiafulvalene (TTF) have been fabricated. A luminance of 5 cd m⁻² has been achieved for a device structure ITO/poly(aniline)/TTF(NO₃)_0.55/Al whose EL spectrum has a broad peak at 645 nm. The devices were fabricated by spin coating from solutions of the adducts. A luminous efficiency of 5×10⁻⁴ lm W⁻¹ has been obtained for these devices which is comparable to that of ITO/poly(aniline)/Alq₃/Al (5.2×10⁻⁴ lm W⁻¹) under same fabrication conditions. The single layer, mixed layer and double layer devices fabricated in this study fit the space charge limited model. Devices fabricated from the adduct [TTF–Alq₃] emit white light (40 cd m⁻²) with a luminous efficiency of 6.6×10⁻⁴ lm W⁻¹. The colour of light emitted appears to depend on the effective oxidation state of TTF in the adducts.     

Fabrication of device for detecting gases using conductivitychanges of electrodeposited Bu4NNi(dmit)2 thinfilms

The fabrication and development of a thin film solid state device for the room temperature detection of sulphur dioxide and nitric oxide is described. Thin films of Bu₄NNi(dmit)₂ were electrodeposited onto a gold interdigitated electrode system and changes in the electrical resistances of the films on exposure to the test gases were monitored. The absorption kinetics followed the Elovich isotherm