Absence of anisotropic universal transport in YBCO

There exists significant in-plane anisotropy between $a$ and $b$ axis for various properties in YBCO. However recent thermal conductivity measurement by Chiao et al. which confirms previous microwave conductivity measurement by Zhang et al., shows no obvious anisotropy in the context of universal transport. We give a possible explanation of why the anisotropy is seen in most properties but not seen in the universal transport.Comment: 4 pages, 4 figure

Triplanar Model for the Gap and Penetration Depth in YBCO

YBaCuO_7 is a trilayer material with a unit cell consisting of a CuO_2 bilayer with a CuO plane of chains in between. Starting with a model of isolated planes coupled through a transverse matrix element, we consider the possibility of intra as well as interplane pairing within a nearly antiferromagnetic Fermi liquid model. Solutions of a set of three coupled BCS equations for the gap exhibit orthorhombic symmetry with s- as well as d-wave contributions. The temperature dependence and a-b in plane anisotropy of the resulting penetration depth is discussed and compared with experiment.Comment: To appear in Physical Review B1 01Mar97; 12 pages with 10 figures; RevTeX+eps

Mapping the broad habitats of the Burren using satellite imagery

Teagasc acknowledges the support of the Research Stimulus Fund of the Department of Agriculture and Food, funded by the Irish Government under the National Development Plan 2000 – 2006.End of project reportThis project has successfully used satellite imagery to survey and map the extent and spatial distribution of broad habitat types within the Burren, and we have represented this information on a digitised habitat map. this information on a digitised habitat map. This map is the first to show the distribution of the broad habitats of the Burren and will be an important tool in aiding future decisions as to how the habitats of the Burren should be managed to the benefit of both the farmer and the environment. The map provides the first estimate of the area of the Burren affected by scrub encroachment – this being one of the most significant threats to the EU priority habitats in the region. On a particularly challenging area with a high diversity and complexity of habitats, remote sensing appears to offer a very effective and cost-efficient alternative to broad-scale habitat mapping on a field-by-field basis. The use of high-resolution imagery and ground-truthing should be adopted to complete a detailed national survey of habitats and land use in Ireland. This would support more effective implementation of both the Agriculture sector’s obligations under the Habitats Directive, and agri-environmental schemes with wildlife objectives. The outputs provided by such mapping approaches could inform the targeting of agri-environmental objectives, and increase the efficiency of detecting areas of high conservation value for monitoring by more conventional methods. The detailed land use descriptions offered by such imagery are also of high relevance to modelling approaches and risk assessment for implementation of land use policies such as the Water Framework Directive and Nitrates Directive.Department of Agriculture, Food and the Marin

Botanical rejuvenation of field margins and benefits for invertebrate fauna on a drystock farm in County Longford

peer-reviewedThis study investigates methods to rejuvenate the fl ora of previously degraded fi eld margins on a pastoral farm in County Longford. We also assess the effects of individual treatments on the abundance of various orders of invertebrates recorded within the experimental plots. Field margin treatments were 1.5m-wide unfenced control margins, 1.5m-wide fenced margins or 3.5m-wide fenced margins. Nutrient inputs were excluded from all of the experimental plots. The botanical composition of the plots was examined on four occasions between 2002 and 2004 using permanent, nested quadrats. Emergence traps were used to measure invertebrate abundance within treatment plots and the main sward. Results indicated that 1) exclusion of nutrient inputs had a positive effect on plant species richness within the fi eld margins; 2) plant species richness decreased with increased distance from the hedgerow; 3) herb species richness was greatest in the 1.5m closest to the hedgerow; 4) greater abundance of invertebrates occurred within the 3.5m-wide margins; 5) successful control of Pteridium aquilinum was achieved through spot treatment with the selective herbicide ‘Asulox’; and 6) a combination of management techniques such as cutting and grazing is likely to enhance plant species richness and facilitate the structural diversity of vegetation that is necessary for many invertebrate taxa.Teagasc Walsh Fellowship Programm