The spin excitation spectrum in superconducting YBa(2)Cu(3)O(6.85)

A comprehensive inelastic neutron scattering study of magnetic excitations in the near optimally doped high-temperature superconductor YBa(2)Cu(3)O(6.85) is presented. The spin correlations in the normal state are commensurate with the crystal lattice, and the intensity is peaked around the wave vector characterizing the antiferromagnetic state of the insulating precursor, YBa(2)Cu(3)O(6). Profound modifications of the spin excitation spectrum appear abruptly below the superconducting transition temperature T(c), where a commensurate resonant mode and a set of weaker incommensurate peaks develop. The data are consistent with models that are based on an underlying two-dimensional Fermi surface, predicting a continuous, downward dispersion relation connecting the resonant mode and the incommensurate excitations. The magnetic incommensurability in the YBa(2)Cu(3)O(6+)(x) system is thus not simply related to that of another high-temperature superconductor, La(2-)(x)Sr(x)CuO(4), where incommensurate peaks persist well above T(c). The temperature-dependent incommensurability is difficult to reconcile with interpretations based on charge stripe formation in YBa(2)Cu(3)O(6+x) near optimum doping.     

A seeding experiment of juvenile great scallops (Pecten maximus (L.)) off the Island of Jersey.

In 1995, landings of Great scallops, Pecten maximus(L.) increased dramatically in Jersey from around one tonne in the previousyear, to 66 tonnes and this continues to rise. This was caused by theintroduction of scallop diving permits and diversification of the fishingfleet.Due to this increase in effort it was decided that the feasibility of ranchingone-year-old juvenile scallops should be investigated. 100,000 scallops werepurchased from Ireland and seeded in specifically selected coastal sites. Thescallops grew from 22.8 mm shell length and 1.17 grams to 57.6mm and 23.2 grams in the first six months after seeding, and to93.3 mm and 88.9 grams during the subsequent 12 months. Growthrateslowed considerably during winter months. Given these growth rates the scallopswill reach market size in three years from settlement, less than the 4, 5 and 6years taken in Guernsey, the Eastern Channel and the offshore Irish Searespectively. Although growth rates are not unique and are comparable withotherinshore sites in the UK, they are significant for scallop farming in Jerseywaters. Mortality following re-seeding and predation rates by crab and starfishappears to be lower than reported by other workers. However this has not yetbeenquantified.     

A seeding experiment of juvenile great scallops (Pecten maximus (L.)) off the Island of Jersey.

In 1995, landings of Great scallops, Pecten maximus(L.) increased dramatically in Jersey from around one tonne in the previousyear, to 66 tonnes and this continues to rise. This was caused by theintroduction of scallop diving permits and diversification of the fishingfleet.Due to this increase in effort it was decided that the feasibility of ranchingone-year-old juvenile scallops should be investigated. 100,000 scallops werepurchased from Ireland and seeded in specifically selected coastal sites. Thescallops grew from 22.8 mm shell length and 1.17 grams to 57.6mm and 23.2 grams in the first six months after seeding, and to93.3 mm and 88.9 grams during the subsequent 12 months. Growthrateslowed considerably during winter months. Given these growth rates the scallopswill reach market size in three years from settlement, less than the 4, 5 and 6years taken in Guernsey, the Eastern Channel and the offshore Irish Searespectively. Although growth rates are not unique and are comparable withotherinshore sites in the UK, they are significant for scallop farming in Jerseywaters. Mortality following re-seeding and predation rates by crab and starfishappears to be lower than reported by other workers. However this has not yetbeenquantified.     

Electron-microprobe analysis of apple fruit tissues affected with bitter pit

The concentrations of the mineral elements K, Ca, Mg, P, S and Cl were compared in pitted and sound tissues of mature fruits of the apple cultivars ‘Akane’, ‘Reine des Reinettes’ and ‘Idared’ using an electron microprobe. Mg, Ca and to a lesser extent S were always present in higher concentrations in pitted areas than in non-pitted ones, in the ratio of 3.0 to 14.4 for Mg and 3.1 to 7.9 for Ca. The K concentration in pitted tissues was variable showing no significant difference in ‘Akane’, and an increase or decrease in ‘Reine des Reinettes’ and ‘Idared’, respectively. P and Cl concentrations were also variable. Serious perturbations were found in the ionic content of the pitted tissues affecting several elements implicated in essential physiological processes.