TILAPIA: BOTH FISH AND FOWL?

Tilapia aquaculture production is now around one million tonnes and is widely tipped to become an even bigger player in the international arena. This paper considers the case for such claims by reviewing the production environment, costs, the key characteristics of the product and its marketing with particular reference to the emergent EU markets and the increasingly established North American market. It is concluded that tilapia has quite distinct comparative advantages, not least being its diverse production scenarios, low cost, and product attributes which are commonly sought by consumers. Coupled with potentially green marketing attributes, it is concluded that this species is likely to appear in a broadening product range including more added value products.Resource /Energy Economics and Policy,

Early History Of ISNA

The International Symposia on Nonlinear Acoustics, now referred to as ISNA, have convened regularly since 1968, bringing together scientists and engineers to report and discuss the latest developments in this branch of nonlinear physics. The fact that this series of symposia is still going strong after more than four decades is testimony that nonlinear acoustics has established itself as a distinct, important, and vibrant field of research. In this paper we take a look back at the early years of ISNA to recall how it all began and trace the evolution of the symposia into their current form.Applied Research Laboratorie

ON A SMALL COLLECTION OF FULGORIDS FROM THE ISLANDS OF KRAKATAU, VERLATEN AND SEBESI.

abstract not availabl

Ragging The Baby To Sleep

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I\u27ve Been Through The Mill

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The effect of water on the post-spinel transition and evidence for extreme water contents at the bottom of the transition zone

The transition of ringwoodite to bridgmanite and periclase (the post-spinel transition) is a strong control on the 660 phase discontinuity and the boundary between the transition zone and the lower mantle. The transition zone may contain significant amounts of water and thus the effect of water on the post-spinel transition must be known to correctly determine its properties. In this paper we examine the transition of ringwoodite to bridgmanite and periclase in both dry and wet conditions using density functional theory (DFT). In the dry case we calculate a high negative Clapeyron slope ( MPa/K at 1873 K). We also find that the Clapeyron slope is significantly nonlinear with temperature and much lower at 1000 K (−1.31 MPa/K) or if determined by linear interpolation from 1000 K (−2.37 MPa/K). The addition of water causes a large broadening of the transition through the development of a phase loop. Seismic studies suggest that the 660 km discontinuity is narrower than 2 km. For this to be the case our results suggest that the water content at the bottom of the transition zone needs to be either less than ∼700 ppm or, alternatively, above ∼8000 ppm (assuming an effective transition width near the maximum transition width). In the latter case this is above the saturation limit for bridgmanite and so will be accompanied by the production of a free water phase/hydrous melt. The hydration of ringwoodite also causes the onset of the transition to deepen with 1 wt% water increasing the depth of the transition by about 8 km. This is relatively small compared to seismically observed variations in the 660 km discontinuity of around 35 km and so water alone cannot account for the observed 660 km discontinuity topography. Water causes no substantial changes to the Clapeyron slope of the transition, so the 660 km topography could be explained by thermal variations of ∼500 K

I Want To Go Home

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