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Louis H. Ahrens
Louis Herman Ahrens (24 April 1918 5 September 1990) was a South African born geochemist, academic, and author. Best known for his work in the 1950s in establishing a method of using rubidium–strontium dating as a means of geochronology. Early life Louis Ahrens was born in Pietermaritzburg, South Africa in April 1918 and a descendant of Lutheran missionaries to the country. He was the son of F.W. Ahrens, a district magistrate and would travel with his father in South Africa and South-West Africa. Barely obtaining a matric, he attended the University of Natal and graduated with a Bachelor of Science degree in geology and chemistry in 1939. He would start his career in Johannesburg in 1940 at the National Institute of Metallurgy (then Government Metallurgical Laboratory) as an analytical chemist with emphasis on optical spectrochemical analysis. During this time he worked on his doctorate thesis in chemistry spectrochemical analysis which was granted in 1944 from the Unive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brackets
A bracket is either of two tall fore- or back-facing punctuation marks commonly used to isolate a segment of text or data from its surroundings. Typically deployed in symmetric pairs, an individual bracket may be identified as a 'left' or 'right' bracket or, alternatively, an "opening bracket" or "closing bracket", respectively, depending on the Writing system#Directionality, directionality of the context. Specific forms of the mark include parentheses (also called "rounded brackets"), square brackets, curly brackets (also called 'braces'), and angle brackets (also called 'chevrons'), as well as various less common pairs of symbols. As well as signifying the overall class of punctuation, the word "bracket" is commonly used to refer to a specific form of bracket, which varies from region to region. In most English-speaking countries, an unqualified word "bracket" refers to the parenthesis (round bracket); in the United States, the square bracket. Glossary of mathematical sym ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Cape Town
The University of Cape Town (UCT) ( af, Universiteit van Kaapstad, xh, Yunibesithi ya yaseKapa) is a public research university in Cape Town, South Africa. Established in 1829 as the South African College, it was granted full university status in 1918, making it the oldest university in South Africa and the oldest university in Sub-Saharan Africa in continuous operation. UCT is organised in 57 departments across six faculties offering bachelor's ( NQF 7) to doctoral degrees ( NQF 10) solely in the English language. Home to 30 000 students, it encompasses six campuses in the Capetonian suburbs of Rondebosch, Hiddingh, Observatory, Mowbray, and the Waterfront. Although UCT was founded by a private act of Parliament in 1918, the Statute of the University of Cape Town (issued in 2002 in terms of the Higher Education Act) sets out its structure and roles and places the Chancellor - currently, Dr Precious Moloi Motsepe - as the ceremonial figurehead and invests real leadership ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Academic Staff Of The University Of Cape Town
An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of secondary or tertiary higher learning (and generally also research or honorary membership). The name traces back to Plato's school of philosophy, founded approximately 385 BC at Akademia, a sanctuary of Athena, the goddess of wisdom and skill, north of Athens, Greece. Etymology The word comes from the ''Academy'' in ancient Greece, which derives from the Athenian hero, ''Akademos''. Outside the city walls of Athens, the gymnasium was made famous by Plato as a center of learning. The sacred space, dedicated to the goddess of wisdom, Athena, had formerly been an olive grove, hence the expression "the groves of Academe". In these gardens, the philosopher Plato conversed with followers. Plato developed his sessions into a method of teaching philosophy and in 387 BC, established what is known today as the Old Academy. By extension, ''academia'' has come to mean the accumulation, dev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South African Chemists
South is one of the cardinal directions or compass points. The direction is the opposite of north and is perpendicular to both east and west. Etymology The word ''south'' comes from Old English ''sūþ'', from earlier Proto-Germanic ''*sunþaz'' ("south"), possibly related to the same Proto-Indo-European root that the word ''sun'' derived from. Some languages describe south in the same way, from the fact that it is the direction of the sun at noon (in the Northern Hemisphere), like Latin meridies 'noon, south' (from medius 'middle' + dies 'day', cf English meridional), while others describe south as the right-hand side of the rising sun, like Biblical Hebrew תֵּימָן teiman 'south' from יָמִין yamin 'right', Aramaic תַּימנַא taymna from יָמִין yamin 'right' and Syriac ܬܰܝܡܢܳܐ taymna from ܝܰܡܝܺܢܳܐ yamina (hence the name of Yemen, the land to the south/right of the Levant). Navigation By convention, the ''bottom or down-facing side'' of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1990 Deaths
Year 199 ( CXCIX) was a common year starting on Monday (link will display the full calendar) of the Julian calendar. At the time, it was sometimes known as year 952 '' Ab urbe condita''. The denomination 199 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * Mesopotamia is partitioned into two Roman provinces divided by the Euphrates, Mesopotamia and Osroene. * Emperor Septimius Severus lays siege to the city-state Hatra in Central-Mesopotamia, but fails to capture the city despite breaching the walls. * Two new legions, I Parthica and III Parthica, are formed as a permanent garrison. China * Battle of Yijing: Chinese warlord Yuan Shao defeats Gongsun Zan. Korea * Geodeung succeeds Suro of Geumgwan Gaya, as king of the Korean kingdom of Gaya (traditional date). By topic Religion * Pope Zephyrinus succeeds Pope Victor I, as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1918 Births
This year is noted for the end of the World War I, First World War, on the eleventh hour of the eleventh day of the eleventh month, as well as for the Spanish flu pandemic that killed 50–100 million people worldwide. Events Below, the events of World War I have the "WWI" prefix. January * January – 1918 flu pandemic: The "Spanish flu" (influenza) is first observed in Haskell County, Kansas. * January 4 – The Finnish Declaration of Independence is recognized by Russian Soviet Federative Socialist Republic, Soviet Russia, Sweden, German Empire, Germany and France. * January 9 – Battle of Bear Valley: U.S. troops engage Yaqui people, Yaqui Native American warriors in a minor skirmish in Arizona, and one of the last battles of the American Indian Wars between the United States and Native Americans. * January 15 ** The keel of is laid in Britain, the first purpose-designed aircraft carrier to be laid down. ** The Red Army (The Workers and Peasants Red Army) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding the National Advisory Committee for Aeronautics (NACA), to give the U.S. space development effort a distinctly civilian orientation, emphasizing peaceful applications in space science. NASA has since led most American space exploration, including Project Mercury, Project Gemini, the 1968-1972 Apollo Moon landing missions, the Skylab space station, and the Space Shuttle. NASA supports the International Space Station and oversees the development of the Orion spacecraft and the Space Launch System for the crewed lunar Artemis program, Commercial Crew spacecraft, and the planned Lunar Gateway space station. The agency is also responsible for the Launch Services Program, which provides oversight of launch operations and countdown management f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Association Of GeoChemistry
The IAGC (International Association of GeoChemistry, formerly known as the International Association of Geochemistry and Cosmochemistry) is affiliated with the International Union of Geological Sciences and has been one of the pre-eminent international geochemical organizations for over thirty-five years. The principal objective of the IAGC is to foster co-operation in, and advancement of, geochemistry in the broadest sense. This is achieved by: # working with any interested group in planning symposia and other types of meetings related to geochemistry, # sponsoring publications in geochemistry of a type not normally covered by existing organizations and, # the activities of working groups which study problems that require, or would benefit from, international co-operation. The scientific thrust of the IAGC takes place through its Working Groups (many of which organize regular symposia) and the official journal, Applied Geochemistry. The specific objectives of the IAGC are: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mineralogical Society Of America
The Mineralogical Society of America (MSA) is a scientific membership organization. MSA was founded in 1919 for the advancement of mineralogy, crystallography, geochemistry, and petrology, and promotion of their uses in other sciences, industry, and the arts. It encourages fundamental research about natural materials; supports the teaching of mineralogical concepts and procedures to students of mineralogy and related arts and sciences; and attempts to raise the scientific literacy of society with respect to issues involving mineralogy. The Society encourages the general preservation of mineral collections, displays, mineral localities, type minerals and scientific data. MSA represents the United States with regard to the science of mineralogy in any international context. The Society was incorporated in 1937 and approved as a nonprofit organization in 1959. Publications * ''American Mineralogist: An International Journal of Earth and Planetary Materials'', is the print journal of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Institute Of Chemistry
The Royal Institute of Chemistry was a British scientific organisation. Founded in 1877 as the Institute of Chemistry of Great Britain and Ireland (ICGBI), its role was to focus on qualifications and the professional status of chemists, and its aim was to ensure that consulting and analytical chemists were properly trained and qualified. The society received its first Royal Charter on 13 June 1885, and King George VI awarded the society royal patronage with effect from 14 May 1943, from which date it became the Royal Institute of Chemistry of Great Britain and Ireland (RICGBI). This re-designation was formally confirmed by the grant of a Supplemental Charter on 29 March 1944. As well as insisting on thorough professional qualifications, it also laid down strict ethical standards. Its main qualifications were Licentiate (LRIC) (professional training following a course of practical study to a standard lower than an honours degree), Graduate (GRIC) (completion of study equivalent to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cape Town
Cape Town ( af, Kaapstad; , xh, iKapa) is one of South Africa's three capital cities, serving as the seat of the Parliament of South Africa. It is the legislative capital of the country, the oldest city in the country, and the second largest (after Johannesburg). Colloquially named the ''Mother City'', it is the largest city of the Western Cape province, and is managed by the City of Cape Town metropolitan municipality. The other two capitals are Pretoria, the executive capital, located in Gauteng, where the Presidency is based, and Bloemfontein, the judicial capital in the Free State, where the Supreme Court of Appeal is located. Cape Town is ranked as a Beta world city by the Globalization and World Cities Research Network. The city is known for its harbour, for its natural setting in the Cape Floristic Region, and for landmarks such as Table Mountain and Cape Point. Cape Town is home to 66% of the Western Cape's population. In 2014, Cape Town was named the best place ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meteorites
A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or moon. When the original object enters the atmosphere, various factors such as friction, pressure, and chemical interactions with the atmospheric gases cause it to heat up and radiate energy. It then becomes a meteor and forms a fireball, also known as a shooting star; astronomers call the brightest examples " bolides". Once it settles on the larger body's surface, the meteor becomes a meteorite. Meteorites vary greatly in size. For geologists, a bolide is a meteorite large enough to create an impact crater. Meteorites that are recovered after being observed as they transit the atmosphere and impact the Earth are called meteorite falls. All others are known as meteorite finds. Meteorites have traditionally been divided into three broad categories: stony meteorites that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
