The rime or rhyme of a syllable consists of a nucleus and an optional coda. Snowflakes encapsulated in rime form balls known as graupel. It involves rhyme recognition, syllables, onset, and rime. The vowel and coda may also be grouped as the "rhyme", sometimes spelled "rime". One hierarchical model groups the syllable nucleus and coda into an intermediate level, the "rime". Additionally, the presence of rime or sleet being mistaken for snowflakes should also be considered. The opposite conditions favour ice with higher densities, such as hard rime or clear ice. Elsewhere, snow can accrete on power lines as "sleeves" of rime ice. He is a part of the rap group Psy 4 de la Rime. Additionally, the tube is heated to prevent rime ice formation on the tube. The term "rime" covers the nucleus plus coda. Thus it is the rime (vowel) that is basic to the system. Hearne may have been one of the inspirations for the "Rime of the Ancient Mariner". See "The Rime of the Ancient Mariner" in popular culture. "Terze rime" in 1575 and "Lettere familiari a diversi" in 1580.