HET acid based oligoesters – TGA/FTIR studies

One of the important reactive halogenated dicarboxylic acids used in the synthesis of flame retardant unsaturated polyester resins is 1,4,5,6,7,7-hexachlorobicyclo [2.2.1] hept-5-ene-2,3-dicarboxylic acid (HET acid). In the present investigation four different oligoesters are synthesized using HET acid as the diacid component and 1,2-ethane diol, 1,2-propane diol, 1,3-propane diol and 1,4-butane diol as the aliphatic diols. Melt condensation technique in vacuum is used for the synthesis of the oligoesters. The number average molecular weights of the oligoesters are determined using end group analysis. The degree of polymerization is estimated to be 3–5. The structural characterization is done using FTIR and NMR (1H and 13C) techniques. In the present investigation, TGA-FTIR studies for the different oligoesters are carried out in nitrogen atmosphere. The materials are heated from ambient to 600 °C at a heating rate of 20 °C/min. The main volatile products identified are CO, HCl, H2O, CO2, hexachlorocyclopentadiene and HET acid/anhydride. The evolution profile of these materials with respect to the structure of the oligoesters is discussed in detail and presented. The importance of β-hydrogens in the diol component and the plausible mechanism for the flame retardant behavior of these oligoesters are presented

Current Status of Crab Fishery in the Artisanal Sector along Gulf of Mannar and Palk bay Coasts

Among the exploited crustacean fishery resources, portunid crabs constitute a significant proportion in the landings along both the east and west coasts of India. From 4% in 1966 the composition of crabs gradually increased and reached 12% in 2006 showing an upward trend from year to year (Rao et al., 1973; Manissery and Radhakrishnan, 2003). This steady increase in the landings of crabs is mainly attributed to the intensification of fishing operation using different types of modern gears and also due to the exploration of new fishing grounds in deeper waters targeting crabs in order to meet the ever increasing demand for the processed crab meats in the domestic as well as in the international markets

Landing of Neophocaena phocaenoides at Rameswaram

Porpoise along Palk Bay coast and Mandapam. Report gives details of morphometric characters of Neophocaena phocaenoides

On two species of marine turtles stranded at Mandapam

A female olive ridely turtle Lepidochelys olivacea was stranded on 21.7.2000 near CMFRI Jetty at Gulf of Mannar coast. Another female green turtle Chelonia mydas was stranded on 6.9.2000 at the same place. Both the turtles had severe injuries resulting in death in the sea and then stranded. Their carapace length was 58, 82 cm' and width 56, 62 cms respectively

Thermal Degradation Studies on PMMA–HET Acid Based Oligoesters Blends

Imparting thermal stability to polymethyl methacrylate (PMMA) without affecting its optical clarity is attempted by incorporating HET acid based oligoesters. Pure PMMA and PMMA containing five and 20 wt% of four different oligoesters are separately prepared using bulk polymerization. The thermal properties of the materials studied using DSC, TG, TG–FTIR and Pyr–GC–MS are presented. The main volatile degradation products identified are CO, HCl, CO2, H2O, hexachlorocyclopentadiene, hexachloroendomethylene tetrahydrophthalic acid/anhydride and methyl methacrylate. A detailed mechanism for the influence of the degradation products of HET acid based oligoesters on the thermal degradation of PMMA is also presented

Landings of porpoise,Neophocaena phocaenoides at Rameswaram.

Paper is reporting the morphometric measurements of female porpoise, Neophocaena phocaenoides caught by gill net, operated off Rameswaram at a depth of 16m

Continuous culture of cladoceran, Moina sp. for rearing of postlarval prawns

A low-cost method for large scale culture of the fresh water cladoceran Moina sp. has been evolved. Moina is used in the frozen condition to feed the postlarvae of penaeid prawns reared at the NPCL of CMFRI

मान्नार खाडी के ज्वारीय क्षेत्र में स्थापित नितलस्थ पिंजरों में पेनिअस सेमिसलकाटस का पालन

कृपया पूरा लेखा पढ

An unusual bumber catch of white prawn, Penaeus indicus from Kovalam bay near Madras

In the history of the fishing village, namely, Kovalam (lat. 12°47'N long. 80°15'E), formerly known as Covelong, situated 35 km south of Madras City, heavy landings of the Indian white prawn, Penaeus indicus caught with gill net have occurred for the firsi time during 16th-20th December, 1984. Recent mark-recapture experiments on P. indicus have also established the fact that a longer migration of tagged white prawns took place from Cochin, (place of release) to Ovari - Manappad fishing villages on the southeast coast (Tinnaveli coast), covering a distance of 330-380 km in 68 to 103 days at a rate of 3.5 to 5.5 km/day. The southward migration of white prawns during the present study was in conjunction with the prevailing southerly current along the coast

First experience in the larviculture of cobia, Rachycentron canadum (Linnaeus, 1752) in India

Cobia aquaculture has been gaining momentum internationally and has spread to more than 23 countries, half of them in the Asia-Pacific region. Envisaging the prospects of cobia farming in India, broodstock development was initiated and the first successful induced breeding was achieved in March 2010. Larviculture was experimented in Fibre Reinforced Plastic (FRP) tanks as well as Reinforced Cement Concrete (RCC) tanks and protocols were evolved. Green water technique employing the microalga, Nannochloropsis oculata was used. The critical stage for the larvae was from 5 to 9 days post-hatch (dph), when cumulative mortality reached around 90%. Enriched rotifers were fed from 3 to 10 dph and enriched Artemia nauplii from 9 to 18 dph. Weaning with larval inert feed was initiated from 18 dph and grading was carried out once in four days to avoid cannibalism. The study was conducted for 31 days and the final larval survival noted in the FRP and RCC tanks were 2 and 1%, respectively. At the end of the experiment, the specific growth rate of larvae in the FRP system was 30.1% of body weight per day, while the same in RCC tank was 28.3% of body weight per day. The low survival and specific growth rate of larvae in the RCC tanks could be attributed to the low densities of live feed maintained. The present experience indicated that cobia seed production can be successfully practised and by refining the methodology, the survival and growth can be enhanced to achieve commercial level fingerling production