Commercialization of Asian seabass, Lates calcarifer as a candidate species for cage culture in India

Asian Seabass (Lates calcarifer) a popular edible marine finfish commands consistent demand in domestic and international markets. It is widely distributed in Indo- Pacific region and extending up to Taiwan, South East Australian coast, Papua New Guinea, Arabian Sea and Bay of Bengal and further to Persian Gulf region. In India, seabass fishery is reported from all along the coast including Andaman & Nicobar Islands. Due to the characteristic catadromous pattern of life cycle, its population occupies a wide range of habitats starting from freshwater lakes, rivers, estuaries and inshore coastal waters. However, the adult fish migrate to deeper inshore sea areas for spawning and as such the early cycle is restricted in seawater areas. Besides, exploiting its natural resources from different environmental conditions, seabass become a compatible species for aquaculture in saline water as well as freshwater conditions

Commercial seed production and farming of Asian seabass Lates calcarifer- Winter School on Recent Advances in Breeding and Larviculture of Marine Finfish and Shellfish

The seabass Lates calcarifer is a marine food fish belongs to family, Centropomidae. This eurihaline fish widely distributed in Indo – Pacific region and abundant much all along the Indian coast. In nature this fish grown to the maximum size of 12 – 14 kg with a TL of 72 – 90 cm and its colour is black at dorsal side and rest of the body is silvery white covered with placoid scales. This fish is highly carnivorous and mainly eats small fishes, crustaceans and mollusks, etc. Though the sexes are separate, the fish initially grown as male upto 4 kg. and subsequently transformed into female and this phenomena is named as “Protrondrus Hermaphroditism” The life cycle of the fish is in two phases i.e., spawning and larval development stages takes place in open sea whereas juveniles, sub adults and adults are in brackish water

Primary productivity of seaweeds in the lagoon of Minicoy atoll of Laccadive archipelago

Net primary production (NPP) of 10 commonly available seaweeds varied from 2 to 10 g C/m3/day. The NPP of Enteromorpha compressa and Hypnea valentiae were the highest and that of Caulerpapeltata was the lowest. The mean of NPP of these 10 seaweeds when measured individually was 5.68 g C/m3/d and that of all seaweeds incubated collectively registered 5.32 g C/m3/d. Hence it is presumed that the probable rate of NPP of seaweed community contributing to Minicoy lagoon is approximately 5g/C/m3/d. Except for C.peltata E.compressa and Gelidiella acerosa. The NPP of other species was higher at bottom than at the surface of the lagoon. The results obtained are discussed in the light of distribution of seaweed in Minicoy Lagoo

Effect of Cavity Vacuum Pressure Diminution on Thermal Performance of Triple Vacuum Glazing

Long-term durability of the vacuum edge-seal plays a significant part in retrofitting triple vacuum glazing (TVG) to existing buildings in achieving towards zero-energy buildings (ZEB) target. Vacuum pressure decrement with respect to time between panes affect the thermal efficiency of TVG. This study reports a 3D finite element model, with validated mathematical methods and comparison, for the assessment of the influence of vacuum pressure diminution on the thermal transmittance (U value) of TVG. The centre-of-pane and total U values of TVG calculated to be 0.28 Wm−2K−1 and 0.94 Wm−2K−1 at the cavity vacuum pressure of 0.001 Pa. The results suggests that a rise in cavity pressure from 0.001 Pa to 100 kPa increases the centre-of-pane and total U values from 0.28 Wm−2K−1 and 0.94 Wm−2K−1 to 2.4 Wm−2K−1 and 2.58 Wm−2K−1, respectively. The temperature descent on the surfaces of TVG between hot and cold sides’ increases by decreasing the cavity vacuum pressure from 50 kPa to 0.001 Pa. To maintain the cavity vacuum pressure of 0.001 Pa for over 20 years of life span in the cavity of 10 mm wide edge sealed triple vacuum glazing, non-evaporable getters will maintain the cavity vacuum pressure that will enable the long-term durability to TVG

Deep penetration of ultra-high molecular weight polyethylene composites by a sharp-tipped punch

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.The penetration of unidirectional (UD) and [0o/90o] cross-ply ultra-high molecular weight polyethylene fibre composites by sharp-tipped cylindrical punches has been investigated. While the measured penetration pressure for both composite types increased with decreasing punch diameter, the pressure was significantly higher for the cross-ply composites and increased with decreasing ply thickness. A combination of optical microscopy and X-ray tomography revealed that in both composites, the sharp-tipped punch penetrated without fibre fracture by the formation of mode-I cracks along the fibre directions, followed by the wedging open of the crack by the advancing punch. In the cross-ply composites, delamination between adjacent 0o and 90o plies also occurred to accommodate the incompatible deformation between plies containing orthogonal mode-I cracks. Micromechanical models for the steady-state penetration pressure were developed for both composites. To account for material anisotropy as well as the large shear strains and fibre rotations, the deformation of the composites was modelled via a pressure-dependent crystal plasticity framework. Intra and inter-ply fracture were accounted for via mode-I and delamination toughnesses respectively. These models account for the competition between deformation and fracture of the plies and accurately predict the measured steady-state penetration pressures over the wide range of punch diameters and ply thicknesses investigated here. Design maps for the penetration resistance of cross-ply composites were constructed using these models and subsequently used to infer composite designs that maximise the penetration resistance for a user prescribed value of fibre strength

Seagrass production in Minicoy Atoll of Lakshadweep Archipelago

Minicoy lagoon harbours extensive beds oiThalassia hemprichii in apsociation with Syringodium isoetifolium, Halophila ovalis and Halodule uninervis. The total area occupied by seagrass flat ranges from 2.0 to 2.2 sq.km. Net primary production (NPP) of seagrass species varied from 5.0 gC/mVday (0.5 gC/kg (wet wt.)/day for Syringodium to 10 gC/m¥day (1.0 gC/kg (wet wt.)/day for Halodule. It was estimated that an impairement upto 50 % on the NPP of Thalassia plants was caused by the prolonged exposure of the beds to bright sunshine in the intertidal areas during ebb stage when compared to those Thalassia plants growing in the unexposed habitats. Wet biomass, density of seagrass species and their NPP potential on the community metabolism of the lagoon are discussed

Compressive response of a 3D non-woven carbon-fibre composite

The compressive response of a three-dimensional (3D) non-interlaced composite comprising three orthogonal sets of carbon fibre tows within an epoxy matrix is analysed. First, the compressive response is measured in three orthogonal directions and the deformation/failure modes analysed by a combination of X-ray tomography and optical microscopy. In contrast to traditional unidirectional and two-dimensional (2D) composites, stable and multiple kinks (some of which zig-zag) form in the tows that are aligned with the compression direction. This results in an overall composite compressive ductility of about 10% for compression in the low fibre volume fraction direction. While the stress for the formation of the first kink is well predicted by a usual micro-buckling analysis, the composite displays a subsequent hardening response associated with formation of multiple kinks. Finite element (FE) calculations are also reported to analyse the compressive response with the individual tows modelled as anisotropic continua via a Hill plasticity model. The FE calculations are in good agreement with the measurements including prediction of multiple kinks that reflect from the surfaces of the tows. The FE calculations demonstrate that the three-dimensionality of the microstructure constrains the kinks and this results in the stable compressive response. In fact, the hardening and peak strength of these composites is not set by the tows in direction of compression, but rather set by the out-of-plane compressive response of the tows perpendicular to the compression direction

Surface instabilities in shock loaded granular media

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.The initiation and growth of instabilities in granular materials loaded by air shock waves are investigated via shock-tube experiments and numerical calculations. Three types of granular media, dry sand, water-saturated sand and a granular solid comprising PTFE spheres were experimentally investigated by air shock loading slugs of these materials in a transparent shock tube. Under all shock pressures considered here, the free-standing dry sand slugs remained stable while the shock loaded surface of the water-saturated sand slug became unstable resulting in mixing of the shocked air and the granular material. By contrast, the PTFE slugs were stable at low pressures but displayed instabilities similar to the water-saturated sand slugs at higher shock pressures. The distal surfaces of the slugs remained stable under all conditions considered here. Eulerian fluid/solid interaction calculations, with the granular material modelled as a Drucker–Prager solid, reproduced the onset of the instabilities as seen in the experiments to a high level of accuracy. These calculations showed that the shock pressures to initiate instabilities increased with increasing material friction and decreasing yield strain. Moreover, the high Atwood number for this problem implied that fluid/solid interaction effects were small, and the initiation of the instability is adequately captured by directly applying a pressure on the slug surface. Lagrangian calculations with the directly applied pressures demonstrated that the instability was caused by spatial pressure gradients created by initial surface perturbations. Surface instabilities are also shown to exist in shock loaded rear-supported granular slugs: these experiments and calculations are used to infer the velocity that free-standing slugs need to acquire to initiate instabilities on their front surfaces. The results presented here, while in an idealised one-dimensional setting, provide physical understanding of the conditions required to initiate instabilities in a range of situations involving the explosive dispersion of particles

Bivalirudin versus heparin in primary PCI: clinical outcomes and cost analysis.

Background: The evidence for benefits of bivalirudin over heparin has recently been challenged. We aimed to analyse the safety and cost-effectiveness following reintroduction of heparin instead of bivalirudin as the standard anticoagulation for primary percutaneous coronary intervention (PPCI) in a high-volume centre. Methods and results: This analysis was an open-label, prospective registry including all patients admitted to our centre for PPCI from April 2014 to April 2016. Heparin was reintroduced as standard anticoagulant in April 2015. During the 2 years, 1291 patients underwent a PPCI, 662 in the Bivalirudin protocol period (Cohort B) and 629 in the Heparin protocol period (Cohort H). Baseline and procedural characteristics were not significantly different, except for a higher use of thromboaspiration and femoral access in the earlier Cohort B. Glycoprotein 2b3a (Gp2b3a) antagonists were used in 24% of the patients in Cohort B versus 28% in Cohort H (P<0.01). We did not observe any differences in death at 180 days (11.03% in Cohort B vs 11.29% in Cohort H)(HR 95% CI 0.98 (0.72 to 1.33), P=0.88). The incidence of any bleeding complications at 30 days did not differ between the two periods (21.9% vs 21.9%, P=0.99). The cost related to the anticoagulants amounted to £246 236 in Cohort B versus £4483 in Cohort H (£324 406 vs £102 347 when adding Gp2b3a antagonists). Conclusion: We did not find clinically relevant changes in patient outcomes, including bleeding complications with reintroduction of heparin in our PPCI protocol. However, the use of heparin was associated with a major reduction in treatment costs