Hayk Mirzayans Insect Museum offers training courses, and helps other scientific research centers in completion and maintenance of their insect collections. ITRD acts as the National Identification Service for governmental or non-governmental organizations, publishes various articles, reports, books, data banks and checklists of its holdings, and provides these information free of charge to all visitors. Hayk Mirzayans Insect Museum The Hayk Mirzayans Insect Museum (HMIM) is the largest insect collection in Iran with over 4 million insect specimens, including 20–25,000 local species, hundreds of primary types and paratypes, and a representative collection of exotic insects, especially tropical butterflies. In 1943, Iranian entomologist established a
Comma (music) Pythagorean comma (PC) and the syntonic comma (SC) are basic intervals that can be used as yardsticks to define some of the other commas. For instance, the difference between them is a small comma called schisma. A schisma is not audible in many contexts, as its size is narrower than the smallest audible difference between tones (which is around six cents, also known as just noticeable difference, or JND). Many other commas have been enumerated and named by microtonalists The syntonic comma has a crucial role in the history of music. It is the amount by which some of the