Anna Dilfi, K F; Dr.Thomas, Kurian(Cochin University of Science & Technology, August , 2011)
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Abstract:
Various compositions of linear low density polyethylene(LLDPE) containing bio-filler(either starch or dextrin)of various particle sizes were prepared.The mechanical,thermal,FTIR,morphological(SEM),water absorption and melt flow(MFI) studies were carried out.Biodegradability of the compositions were determined using a shake culture flask containing amylase producing bacteria(vibrios),which were isolated from marine benthic environment and by soil burial test. The effect of low quantities of metal oxides and metal stearate as pro-oxidants in LLDPE and in the LLDPE-biofiller compositions was established by exposing the samples to ultraviolet light.The combination of bio-filler and a pro-oxidant improves the degradation of linear low density polyethylene.The maleation of LLDPE improves the compatibility of the c blend components and thepro-oxidants enhance the photodegradability of the compatibilised blends.The responsibility studies on the partially biodegradable LLDPE containing bio-fillers and pro-oxidants suggest that the blends could be repeatedly reprocessed without deterioration in mechanical properties.
Description:
Dept.of Polymer Science and Rubber Technology,Cochin University of Science and Technology
Sarita,G Bhat; Dr.Bright Singh,I S(Cochin University of Science and Technology, May , 1998)
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Abstract:
The great potential for the culture of non-penaeid prawns, especially
Macrobrachium rosenbergii in brackish and low saline areas of Indian coastal zone has
not yet been fully exploited due to the non availability of healthy seed in adequate numbers
and that too in the appropriate period. In spite of setting up several prawn hatcheries
around the country to satiate the ever growing demands for the seed of the giant fresh
water prawn, the supply still remains fear below the requirement mainly due to the
mortality of the larvae at different stages of the larval cycle. In a larval rearing system of
Macrobrachium rosenbergii, members of the family Vibrionaceae were found to be
dominant flora and this was especially pronounced during the times of mortality
However, to develop any sort of prophylactic and therapeutic measures, the pathogenic
strains have to be segregated from the lot. This would never be possible unless they were
clustered based on the principles of numerical taxonomy It is with these objectives and
requirements that the present work involving phenotypic characterization of the isolates
belonging to the family Vibrionaceae and working out the numerical taxonomy,
determination of mole % G+C ratio, segregation of the pathogenic strains and screening
antibiotics as therapeutics at times of emergency, was carried out.
Description:
School of Environmental Studies.Cochin University of Science and Technology
Bright Singh, I S; Rosamma, Philip; Rejish Kumar, V J; Jayaprakash, N S(Blackwell Publishing Ltd, March 1, 2006)
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Abstract:
Surveys for bacteriological analysis of larval samples
to isolate the associated vibrios were carried out during
1985^1992, 2001 and 2002 in three di¡erent
hatcheries located on the southwest coast of India.
Vibrio isolates were examined for their species diversity,
virulence based on haemolysis in prawn blood
agar, lipolysis, proteolysis and chitinolysis and antibiotic
sensitivity.Vibrio cholerae was the predominant
species in the apparently healthy larval samples,
whereas V. alginolyticus and V. vulni¢cus dominated
during disease and morbidity. No correlation was
found between the hydrolytic properties and haemolytic
activity of the vibrios associated with the larvae.
All isolates were resistant to erythromycin and resistance
to oxytetracycline, ampicillin and streptomycin
sulphate was prevalent among the larger section of
the Vibrio population. This suggested that antibiotic
application may not be of much use to protect the larvae
fromvibriosis. This is the ¢rst report on the diversity
of Vibrio species associated with Macrobrachium
rosenbergii larvae and their virulence characteristics
based on haemolysis in prawn blood agar