Girijavallabhan, C P; Radhakrishnan, P; V P N Nampoori; Nibu, A George; George, A K(Journal of Physica: Condensed Matter, Institute of Physics Publishing, November 28, 2000)
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Abstract:
The thermal effusivity values in the isotropic phase of certain comb-shaped
polymers have been evaluated for the first time using an open photoacoustic
cell configuration. The compounds investigated have siloxane and acrylate
backbone and they carry mesogenic groups in their side chain. The results
indicate that the polymer chain length as well as the side chain length have
pronounced influence on the thermal effusivity values in liquid crystalline
polymers.
Radhakrishnan, P; V P N Nampoori; Girijavallabhan, C P; Nibu, A George; George, A K(Journal of Physica: Condensed Matter, Institute of Physics Publishing, November 28, 2000)
[+]
[-]
Abstract:
The thermal effusivity values in the isotropic phase of certain comb-shaped
polymers have been evaluated for the first time using an open photoacoustic
cell configuration. The compounds investigated have siloxane and acrylate
backbone and they carry mesogenic groups in their side chain. The results
indicate that the polymer chain length as well as the side chain length have
pronounced influence on the thermal effusivity values in liquid crystalline
polymers
Jyothi, T M; Sugunan, S; Rao, B S(Catalysis Letters, 2000)
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Abstract:
A comparative study on the anisole methylation with methanol over lanthanum-promoted Sn02 catalyst and its sulfate-doped analogue
is presented. A maximum 2.6-xylenol selectivity of 82% was achieved at 400 degreeC under optimized conditions at an anisole
conversion of 65% over lanthanum-promoted Sn02 catalyst. The sulfate modification resulted in the dealkylation of anisole to phenol
followed by several unselective side reactions due to the creation of strong acid sites. The activity of lanthanum-modified tin oxide
catalysts in the selective formation of 2.6-xylenol is ascribed to the presence of weak Lewis acid sites and comparatively stronger basic
sites.
In Vembanad Lake and its confluent rivers (Kerala, India), the catches of Macrobrachium rosenbergii (de Man) were reported
to have dwindled to a mere 39 t in the 1980s from average landings of 300 t during the 1960s. This decline is due to the impact
of a number of human interventions affecting the ecosystem and, hence, the stocks of M. rosenbergii. Monitoring of landings in
1994-1995 and 1995-1996 indicates an improvement in catches. This paper discusses the reasons for the decline and revival
in stocks and suggestions for their replenishment.
V P N Nampoori; Radhakrishnan, P; Girijavallabhan, C P; Nibu, A George; George, A K(Journal of Physica: Condensed Matter, Institute of Physics Publishing, November 28, 2000)
[+]
[-]
Abstract:
The thermal effusivity values in the isotropic phase of certain comb-shaped
polymers have been evaluated for the first time using an open photoacoustic
cell configuration. The compounds investigated have siloxane and acrylate
backbone and they carry mesogenic groups in their side chain. The results
indicate that the polymer chain length as well as the side chain length have
pronounced influence on the thermal effusivity values in liquid crystalline
polymers
Girijavallabhan, C P; Radhakrishnan, P; V P N Nampoori; George, N A; Paul, T; Sebastian, M T(Journal of Materials Science Letters,Kluwer Academic Publishers, 2000)
Ceramic dielectric resonators in the BaO-RE2O3-TiO2 (RE=rare earth) system have been
prepared by the conventional solid state ceramic route. The dielectric properties have been
tailored by substitution of different rare earth oxides and by bismuth oxide addition. The
dielectric constants increased with Bi addition whereas the Q decreased. The temperature
coeffecient of the resonant frequency improved with bismuth addition.
Radhakrishnan, P; V P N Nampoori; Girijavallabhan, C P; George, N A; Paul, T; Sebastian, M T(Journal of Materials Science Letters,Kluwer Academic Publishers, 2000)
V P N Nampoori; Radhakrishnan, P; Girijavallabhan, C P; George, N A; Paul, T; Sebastian, M T(Journal of Materials Science Letters,Kluwer Academic Publishers, 2000)