K B Lal
Articles written in Bulletin of Materials Science
Volume 24 Issue 5 October 2001 pp 475-482 Crystal Growth
The growth of Sb-based crystals (InSb, GaSb etc) was undertaken using resistive heater furnace by vertical directional solidification (VDS) technique. Crystal–melt interface shape during the growth was shown to convert from concave to convex along the crystal axis of the ingots. Many antimonide (Sb) crystals of 8 mm to 18 mm diameter were grown by optimized growth parameters. The forced convection and absence of conducting support to ampoule showed improvement in crystal quality of as grown ingots. Crystals showed preferred orientation and self-seeding. Results on interface shape and crystallinity of ingots were found to be in good agreement with the experiments.
Volume 26 Issue 2 February 2003 pp 221-225 Sol-gel Materials
The synthesis of titania membrane through sol–gel route involves hydrolysis of alkoxide, peptization of hydrous oxide of titanium to obtain a sol, adjustment of the sol viscosity by including a binder and filtration of the viscous sol through a microporous support, gelation and sintering to desired temperature. The binder plays an important role in that it not only helps in adjustment of sol viscosity but also helps in binding the sol particle with porous support. Here a comparative study on the role of different binders, viz. polyvinyl alcohol, polyethyleneimine, polyacrylamide, effect of their viscosity and surface tension effect on the morphology of the titania membrane is presented. The results show that among the three binders studied polyvinyl alcohol gave rise to membranes of desired characteristics when the sol viscosity was 0.08 pa.s.
Volume 30 Issue 5 October 2007 pp 521-526 Cement
Study on the cementation of the regenerated activity (from spent resin using ferric as regenerant) containing ferric in cement matrix showed that compressive strength and leaching behaviour are better when the ferric strength was < 5 N. The diffusion coefficient of Cs from the cement matrix was found to be in the range 2.4 × 10-5 cm2/day and 5.9 × 10-5 cm2/day with ferric solutions of strength in the range 0.5–3 N. When bentonite and vermiculite were included in the cement matrix, the diffusion coefficient of Cs was found to be in the range 6.2 × 10-7 cm2/day to 1.26 × 10-5 cm2/day with ferric strength in the same range.
Volume 42 | Issue 5
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