Rani, Joseph(Gordon and Breach Science Publishers, Inc., November 28, 1986)
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Abstract:
Polymer-solvent interaction parameters for the blends of natural rubber (NR) with
styrene-butadiene rubber (SBR) and polybutadiene rubber ( BR) are calculated using
the Flory-Rehner equation by equating the network density of the vulcanizates in
two solvents.
Paulose,C S; Dakshinamurti,K; Subah,Packer; Newman,L Stephens(Department of Biotechnology, 1986)
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Abstract:
Pyridoxal phosphate (PLP) is the coenzyme of various decarboxylases involved in the
formation of monoamine urotransmitters such as y-aminobulyric acid (GAE3A),
serotonin (5-HT) and dopamine. 1-lowever; in the pyridoxine-deficient rats GABA and
5-HT are decreased in various brain areas including the hypothalamus, with no change
in the catecholamine levels. Serotonin and GABA are known to be involved in blood
pressure control mechanisms. In this study adult Sprague-Dawley rats placed on a
pyridoxine-deficient diet for 8 weeks showed significant hypertension compared with
pyridoxine-supplemented controls. This was associated with a general sympathetic
stimulation. Treatment of deficient rats with a single dose of pyridoxine (10 mg/kg body
weight) reversed the blood pressure to normal levels within 24 h, with concomitant
restoration of hypothalamic 5-HT and GABA, as well as the return of plasma
norepinephrine to nornr;l levels. The results indicate that there is a cause-and-effect
relationship between pyridoxine deficiency and hypertension.
Rani, Joseph(Huthig & Wepf Verlag, Basel, April 29, 1986)
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Abstract:
Tribasic lead sulphate is tried as a practical curing agent for polychloroprene. The
cure characteristics of the compounds as well as the technical properties of the
vulcanizates show that it can act as a potential curative.
Rani, Joseph(Hitthig & Wepf Verlag, Basel, October 13, 1986)
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Abstract:
A carbon black filled 50/50 natural rubber (NR)/styrene-butadiene rubber (SBR)
blend is vulcanized using several conventional curing systems designed by varying the
amounts of sulphur and accelerator. The cure characteristics and the properties of the
vulcanizates are compared. The quantity and quality of crosslinks in each case are
evaluated by chemical probes to correlate them with the properties.
Rani, Joseph(Gordon and Breach Science Publishers, Inc., November 13, 1986)
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Abstract:
A carbon black filled 50/50 Natural Rubber (NR)/Polybutadiene Rubber (BR) blend
is vulcanized using several conventional systems designed by varying the amounts of
sulphur and accelerator . The cure characteristics and the vulcanizate properties are
compared. The quality and quantity of crosslinks in each case are deciphered by
chemical probes to correlate them with the vulcanizate properties.
Sudha Kartha, C; Ramachandran, T; Nampoori, V P N; Sathianandan, K(Elsevier, 1986)
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Abstract:
Variations in the decay times of the characteristic green emissions at 522.7, 551.3, 549.6, 547.6, 542.2, 540.2, 535.9 and 533.5 nm from CaF2:Ho3+ with concentration are studied at RT and LNT. A pulsed N2 laser beam of power density 1.5 MW cm-2 is used for the excitation. Temperature dependent concentration quenching of the decay times are observed for all the emission bands. But an increase in the decay time due to the reabsorption process is also observed for a few of the above bands.
Studies conducted on butadiene-acrylonitrile copolymer (NBR)/poly(vinyl chloride) (PVC)
blends at different temperatures indicate that an optimum temperature exists for the formation
of a particular blend. The mechanical properties of the blends confirm this observation.
PVC stabilizer based on, magnesium oxide , zinc oxide, and stearic acid was found to be very
useful in NBR/PVC blends.