Live food organisms – Artemia Part II - Artemia cyst and biomass production

The brine shrimp, Artemia a crustacean which is naturally found in hypersaline waters throughout most of the world, has become the most important source of live-feed for the last twenty years. All its life stages such as cysts after decapsulation, freshly hatched nauplii, juveniles, preadults and adults, are used as live-feed according to the feed-size requirement of the predator. Artemia decapsulated cysts and freshly hatched nauplii form as ideal food for the larvae of cultured fish and crustaceans in their hatchery phase while juveniles, pre adults and adults form as suitable diet for prawn/fish juveniles in their nursery phase

Live food organisms – Artemia Part I. Artemia cysts and their utilization

Extensive literature reveals that only very few organisms have been utilized as live feed of which the brine shrimp Artemia, is the most important one. In the growing aquaculture industry, a great demand exists for Arteinia cysts which form as dried inert food source. In these cysts embryos, after development upto gastrula stage, are kept in diapause. The cysts are brownish in colour and mi^asure about 0.3 mm in diameter. When dehydrated, they are biconcave in shape

Direct Evidence of Mg Incorporation Pathway in Vapor-Liquid-Solid Grown p-type Nonpolar GaN Nanowires

Doping of III-nitride based compound semiconductor nanowires is still a challenging issue to have a control over the dopant distribution in precise locations of the nanowire optoelectronic devices. Knowledge of the dopant incorporation and its pathways in nanowires for such devices is limited by the growth methods. We report the direct evidence of incorporation pathway for Mg dopants in p-type nonpolar GaN nanowires grown via vapour-liquid-solid (VLS) method in a chemical vapour deposition technique for the first time. Mg incorporation is confirmed using X-ray photoelectron (XPS) and electron energy loss spectroscopic (EELS) measurements. Energy filtered transmission electron microscopic (EFTEM) studies are used for finding the Mg incorporation pathway in the GaN nanowire. Photoluminescence studies on Mg doped GaN nanowires along with the electrical characterization on heterojunction formed between nanowires and n-Si confirm the activation of Mg atoms as p-type dopants in nonpolar GaN nanowires.Comment: 29 pages, 6 figures, journa

Mapping the potential energy surfaces for ring-closing metathesis reactions of prototypical dienes by electronic structure calculations

The potential energy surfaces for ring-closing metathesis reactions of a series of simple alpha,omega-dienes which lead to 5-10 membered ring products, have been explored using density functional theory methods. We have investigated both the conformational aspects of the hydrocarbon chain during the course of the reactions, as well as the stationary structures on the corresponding potential energy surfaces. Extensive conformational searches reveal that the reaction proceeds via the conformation that would be expected for the cycloalkene product, though most unexpectedly, cyclohexene forms via complexes in boat-like conformations. The M06-L density functional has been used to map out the potential energy surfaces, and has identified metallocyclobutane fragmentation as being generally the highest barrier along the pathway. The structural variations along the pathway have been discussed for the reactant hydrocarbons of differing chain length to identify points at which cyclisation events may begin to affect reaction rates. Our study provides an excellent starting point from which to begin to learn about the way RCM reaction outcomes are controlled by diene structur

Oscillation Criteria of Second-Order Quasi-Linear Neutral Delay Difference Equations

2000 Mathematics Subject Classification: 39A10.The oscillatory and nonoscillatory behaviour of solutions of the second order quasi linear neutral delay difference equation Δ(an | Δ(xn+pnxn-τ)|α-1 Δ(xn+pnxn-τ) + qnf(xn-σ)g(Δxn) = 0 where n ∈ N(n0), α > 0, τ, σ are fixed non negative integers, {an}, {pn}, {qn} are real sequences and f and g real valued continuous functions are studied. Our results generalize and improve some known results of neutral delay difference equations

Large scale phytoplankton batch cultures for rearing of marine prawn larvae

Successful rearing of penaeid prawn larvae depends on the continuous availability of desired species of phytoplankton. A breakthrough in the culture of penaeid larvae was achieved by Japanese scientist Hudinaga when he was able to cultu re the diatom Skeletonema cost8tum to feed the Penaeus japonicus larvae