Vowel whose quality does not change over the duration of the vowel is called a monophthong. Monophthongs are sometimes called "pure" or "stable" vowels. A vowel sound that glides from one quality to another is called a diphthong, and a vowel sound that glides successively through three qualities is a triphthong. All languages have monophthongs and many languages have diphthongs, but triphthongs or vowel sounds with even more target qualities are relatively rare cross-linguistically. English has all three types: the vowel sound in "hit" is a monophthong , the vowel sound in "boy" is in most dialects a diphthong , and
Types of mesh to know how good your mesh is from the point of purpose of comparative results. There are two types of two-dimensional cell shapes that are commonly used. These are the triangle and the quadrilateral. Computationally poor elements will have sharp internal angles or short edges or both. This cell shape consists of 3 sides and is one of the simplest types of mesh. A triangular surface mesh is always quick and easy to create. It is most common in unstructured grids. This cell shape is a basic 4 sided one as shown in the figure. It is most common in