African UnionThe African Union (AU) is a continental union consisting of 55 member states located on the continent of Africa. The AU was announced in the Sirte Declaration in Sirte, Libya, on 9 September 1999, calling for the establishment of the African Union. The bloc was founded on 26 May 2001 in Addis Ababa, Ethiopia, and launched on 9 July 2002 in Durban, South Africa. The intention of the AU was to replace the Organization of African Unity (OAU), established on 25 May 1963 in Addis Ababa by 32 signatory governments; the OAU was disbanded on 9 July 2002.
African diasporaThe global African diaspora is the worldwide collection of communities descended from Native Africans or people from Africa, predominantly in the Americas. The term most commonly refers to the descendants of the native West and Central Africans who were enslaved and shipped to the Americas via the Atlantic slave trade between the 16th and 19th centuries, with their largest populations in the United States, Brazil, and Haiti (in that order).
PorosityPorosity or void fraction is a measure of the void (i.e. "empty") spaces in a material, and is a fraction of the volume of voids over the total volume, between 0 and 1, or as a percentage between 0% and 100%. Strictly speaking, some tests measure the "accessible void", the total amount of void space accessible from the surface (cf. closed-cell foam). There are many ways to test porosity in a substance or part, such as industrial CT scanning.
Pan-AfricanismPan-Africanism is a worldwide movement that aims to encourage and strengthen bonds of solidarity between all indigenous and diasporas of African ancestry. Based on a common goal dating back to the Atlantic slave trade, the movement extends beyond continental Africans with a substantial support base among the African diaspora in the Americas and Europe.
Banach spaceIn mathematics, more specifically in functional analysis, a Banach space (pronounced ˈbanax) is a complete normed vector space. Thus, a Banach space is a vector space with a metric that allows the computation of vector length and distance between vectors and is complete in the sense that a Cauchy sequence of vectors always converges to a well-defined limit that is within the space. Banach spaces are named after the Polish mathematician Stefan Banach, who introduced this concept and studied it systematically in 1920–1922 along with Hans Hahn and Eduard Helly.
Effective porosityEffective porosity is most commonly considered to represent the porosity of a rock or sediment available to contribute to fluid flow through the rock or sediment, or often in terms of "flow to a borehole". Porosity that is not considered "effective porosity" includes water bound to clay particles (known as bound water) and isolated "vuggy" porosity (vugs not connected to other pores). The effective porosity is of great importance in considering the suitability of rocks or sediments as oil or gas reservoirs, or as aquifers.
