Search results
Results from the WOW.Com Content Network
Under the recommendation of the Seventh Central Pay Commission, the CCA classification was abolished in 2008. The earlier HRA classification of cities was changed from A-1 to X; A, B-1, and B-2 to Y; and C and unclassified cities to Z. [2] [3] [4] X, Y, and Z are more commonly known as Tier-1, Tier-2, and Tier-3 cities, respectively.
Thus, some cathedral cities in England (e.g., Ely, Cambridgeshire) have a much smaller populations than some towns (e.g., Luton). In some parts of the United States, the distinction between town and city is a matter of a decision by local government to incorporate.
In the decade of 1991–2001, migration to major cities caused rapid increase in urban population. [7] [8] The number of Indians living in urban areas has grown by 31.2% between 1991 and 2001. [9] Yet, in 2001, over 70% lived in rural areas.
The urban hierarchy ranks each city based on the size of population residing within the nationally defined statistical urban area. Because urban population depends on how governments define their metropolitan areas, urban hierarchies are conventionally ranked at the national level; however, the ranking can be extended globally to include all cities.
It indicates the mathematical group for the topological invariant of the topological insulators and topological superconductors, given a dimension and discrete symmetry class. [1] The ten possible discrete symmetry families are classified according to three main symmetries: particle-hole symmetry , time-reversal symmetry and chiral symmetry .
Urbanization has a great impact on biodiversity. As cities develop, vital habitats are destroyed or fragmented into patches which leads to them not being big enough to support complex ecological communities. In cities, species can become endangered or locally extinct. The human population is the main contributor to the expansion of urban areas.
Physics (i.e. mathematical physics) is particularly well represented in the classification scheme with a number of different categories including: Fluid mechanics; Quantum mechanics; Geophysics; Optics and electromagnetic theory; All valid MSC classification codes must have at least the first-level identifier.
This article consists of tables outlining a number of physical quantities.. The first table lists the fundamental quantities used in the International System of Units to define the physical dimension of physical quantities for dimensional analysis.