|
Rho
Rho (; uppercase Ρ, lowercase ρ or ; or ) is the seventeenth letter of the Greek alphabet. In the system of Greek numerals it has a value of 100. It is derived from Phoenician alphabet, Phoenician letter resh . Its uppercase form uses the same glyph, Ρ, as the distinct Latin alphabet, Latin letter P; the two letters have #Character encodings, different Unicode encodings. Uses Greek Rho is classed as a liquid consonant (together with Lambda (letter), Lambda and sometimes the nasals Mu (letter), Mu and Nu (letter), Nu), which has important implications for Morphology (linguistics), morphology. In both Ancient Greek, Ancient and Modern Greek, it represents an alveolar trill , alveolar tap , or alveolar approximant . In polytonic orthography, a rho at the beginning of a word is almost always written ⟨⟩ (''rh'') with a rough breathing mark, indicating that it is voiceless consonant, voiceless. Very rarely, it is written ⟨⟩ (''r'') with a smooth breathing mark, indicatin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass Density
Density (volumetric mass density or specific mass) is the ratio of a substance's mass to its volume. The symbol most often used for density is ''ρ'' (the lower case Greek language, Greek letter rho), although the Latin letter ''D'' (or ''d'') can also be used: \rho = \frac, where ''ρ'' is the density, ''m'' is the mass, and ''V'' is the volume. In some cases (for instance, in the United States oil and gas industry), density is loosely defined as its weight per unit volume, although this is scientifically inaccurate this quantity is more specifically called specific weight. For a pure substance, the density is equal to its mass concentration (chemistry), mass concentration. Different materials usually have different densities, and density may be relevant to buoyancy, purity and packaging. Osmium is the densest known element at standard conditions for temperature and pressure. To simplify comparisons of density across different systems of units, it is sometimes replaced by t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Density
The density of air or atmospheric density, denoted '' ρ'', is the mass per unit volume of Earth's atmosphere at a given point and time. Air density, like air pressure, decreases with increasing altitude. It also changes with variations in atmospheric pressure, temperature, and humidity. According to the ISO International Standard Atmosphere (ISA), the standard sea level density of air at 101.325 kPa (abs) and is . At the non-standard sea level temperature of , the density would decrease to . This is about that of water with a density of about . Air density is a property used in many branches of science, engineering, and industry, including aeronautics;Olson, Wayne M. (2000) AFFTC-TIH-99-01, Aircraft Performance FlightICAO, Manual of the ICAO Standard Atmosphere (extended to 80 kilometres (262 500 feet)), Doc 7488-CD, Third Edition, 1993, .Grigorie, T.L., Dinca, L., Corcau J-I. and Grigorie, O. (2010) Aircraft's Altitude Measurement Using Pressure Information:Barometric Altitud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liquid Consonant
In linguistics, a liquid consonant or simply liquid is any of a class of consonants that consists of rhotics and voiced lateral approximants, which are also sometimes described as "R-like sounds" and "L-like sounds". The word ''liquid'' seems to be a calque of the Ancient Greek word (; ), initially used by grammarian Dionysius Thrax to describe Greek sonorants. Liquid consonants are more prone to be part of consonant clusters and of the syllable nucleus. Their third formants are generally non-predictable based on the first two formants. Another important feature is their complex articulation, which makes them a hard consonant class to study with precision and the last consonants to be produced by children during their phonological development. They are also more likely to undergo certain types of phonological changes such as assimilation, dissimilation and metathesis. Most languages have at least one liquid in their phonemic inventory. English has two, and . His ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
