Irish dance (typically the top half of dancers graded after the first two rounds) of dancers are invited back to perform. The Céilí dances used in competitions are more precise versions of those danced in less formal settings. There is a list of 30 Céilí dances which have been standardised and published in An Coimisiún's "Ar Rinncidhe Foirne" as examples of typical Irish folk dances; these are called the "book" dances by competitive stepdancers. Most Irish dancing competitions only ask for a short piece of any given dance, in the interests of time. There are two types of shoes; soft shoes (also
Irish Sea North Channel about a year after discharge. Measurements of technetium concentrations post-1994 has produced estimated transit times to the North Channel of around six months with peak concentrations off the northeast Irish coast occurring 18–24 months after peak discharge. Less soluble elements such as plutonium are subject to much slower redistribution. Whilst concentrations have declined in line with the reduction in discharges they are markedly higher in the eastern Irish Sea compared to the western areas. The dispersal of these elements is closely associated with sediment activity, with muddy deposits on the seabed acting as sinks, soaking up an estimated