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Samrong Sen
Samrong Sen (alternates: Somron-Seng, Somrong Seng, Somrong Sen, Som-Ron-Sen;Sophady (2007), p. 7 km, សំរោងសែន) on the east bank of the Stueng Chinit River is a prehistoric archaeological site in the Kampong Chhnang Province, Cambodia. Consisting of a very large fluviatile shell midden, it flourished in particular from 1500 BC to 500 BC. Excavations at Samrong Sen, which started in the 1880s, have been described as the earliest prehistoric archaeological studies which gave credence to the concept of Southeast Asian Bronze Age.Miksic (2003), p. 208 Excavations conducted to depths of stratifications have revealed that Samrong Sen provides a link to the professional skills and burial practices of the Bronze Age communities who lived in the Banchiang area on the banks of the Chinit River. As Samrong Sen was almost the only known prehistoric settlement in Cambodia for many years, it was visited by many archaeologists and its artefacts were studied by scientists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Christian Era
The terms (AD) and before Christ (BC) are used to label or number years in the Julian and Gregorian calendars. The term is Medieval Latin and means 'in the year of the Lord', but is often presented using "our Lord" instead of "the Lord", taken from the full original phrase "''anno Domini nostri Jesu Christi''", which translates to 'in the year of our Lord Jesus Christ'. The form "BC" is specific to English and equivalent abbreviations are used in other languages: the Latin form is but is rarely seen. This calendar era is based on the traditionally reckoned year of the conception or birth of Jesus, ''AD'' counting years from the start of this epoch and ''BC'' denoting years before the start of the era. There is no year zero in this scheme; thus ''the year AD 1 immediately follows the year 1 BC''. This dating system was devised in 525 by Dionysius Exiguus, but was not widely used until the 9th century. Traditionally, English follows Latin usage by placing the "AD" abbr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kampong Chhnang City
Kampong Chhnang ( km, កំពង់ឆ្នាំង ) is the capital city of Kampong Chhnang Province, in central Cambodia. It is located just west of the Tonlé Sap River and is a noted port. The small city is connected to Phnom Penh by a national highway route and railway. Phnom Kong Rei is a landmark located north of the city across the Tonle Sap River. The economy of the area is dominated by rice production and many locals live on floating fishing villages during the high-water monsoon season. References External links at the Cambodia National and Provincial Resources Data Bank ...
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Oudong
( km, ឧដុង្គ; also romanized as Udong or Odong) is a former town of the post-Angkorian period (1618–1863) situated in present-day ''Phsar Daek'' Commune, Ponhea Lueu District, Kandal Province, Cambodia. Located at the foothill of the mountain Phnom Oudong, also known as Phnom Preah Reach Troap ( km, ភ្នំព្រះរាជ្យទ្រព្យ), about 35 km northwest of the modern capital Phnom Penh via National Road No. 5, Oudong was a royal residence and Cambodia's capital for almost 250 years until 1866. A monumental royal necropolis of sovereigns of several centuries is scattered on top of the prominent bisected mountain, which runs from the southeast to the northeast. Etymology The city's name is derived from the Sanskrit word "" ( sa, उत्तुङ्ग), meaning tall, which probably refers to the mountain. As it had gained religious merit and significance it might have undergone extension towards: "great" or "supreme". History Oudong was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon-14
Carbon-14, C-14, or radiocarbon, is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons. Its presence in organic materials is the basis of the radiocarbon dating method pioneered by Willard Libby and colleagues (1949) to date archaeological, geological and hydrogeological samples. Carbon-14 was discovered on February 27, 1940, by Martin Kamen and Sam Ruben at the University of California Radiation Laboratory in Berkeley, California. Its existence had been suggested by Franz N. D. Kurie, Franz Kurie in 1934. There are three naturally occurring isotopes of carbon on Earth: carbon-12 (), which makes up 99% of all carbon on Earth; carbon-13 (), which makes up 1%; and carbon-14 (), which occurs in trace amounts, making up about 1 or 1.5 atoms per 1012 atoms of carbon in the atmosphere. Carbon-12 and carbon-13 are both stable, while carbon-14 is unstable and has a half-life of 5,730 ± 40 years. Carbon-14 decays into nitrogen-14 () through bet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accelerator Mass Spectrometry
Accelerator mass spectrometry (AMS) is a form of mass spectrometry that accelerates ions to extraordinarily high kinetic energies before mass analysis. The special strength of AMS among the mass spectrometric methods is its power to separate a rare isotope from an abundant neighboring mass ("abundance sensitivity", e.g. 14C from 12C). The method suppresses molecular isobars completely and in many cases can separate atomic isobars (e.g. 14N from 14C) also. This makes possible the detection of naturally occurring, long-lived radio-isotopes such as 10Be, 36Cl, 26Al and 14C. Their typical isotopic abundance ranges from 10−12 to 10−18. AMS can outperform the competing technique of decay counting for all isotopes where the half-life is long enough. Other advantages of AMS include its short measuring time as well as its ability to detect atoms in extremely small samples. The method Generally, negative ions are created (atoms are ionized) in an ion source. In for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiocarbon Dating
Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was developed in the late 1940s at the University of Chicago by Willard Libby. It is based on the fact that radiocarbon () is constantly being created in the Earth's atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting combines with atmospheric oxygen to form radioactive carbon dioxide, which is incorporated into plants by photosynthesis; animals then acquire by eating the plants. When the animal or plant dies, it stops exchanging carbon with its environment, and thereafter the amount of it contains begins to decrease as the undergoes radioactive decay. Measuring the amount of in a sample from a dead plant or animal, such as a piece of wood or a fragment of bone, provides information that can be used to calc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spearheads
An armoured spearhead (American English: armored spearhead) is a formation of armoured fighting vehicles, mostly tanks, that form the front of an offensive thrust during a battle. The idea is to concentrate as much firepower into a small front as possible, so any defenders in front of them will be overwhelmed. As the spearhead moves forward, infantry units following in the gap behind them form up on either side of the line of advance in order to protect the flanks. The tactic is quite risky. A determined enemy can counterattack against the infantry on the flanks, thereby cutting off the spearhead from resupply and quickly bringing it to a halt. In order to avoid this the spearhead must move as fast as possible in order to keep the defense from re-organizing in this fashion . The first use of an armored spearhead was during World War II in the 1940 Battle of France, the German Army's invasion of the Low Countries, against the British and French armies . Surprising them out of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crucible
A crucible is a ceramic or metal container in which metals or other substances may be melted or subjected to very high temperatures. While crucibles were historically usually made from clay, they can be made from any material that withstands temperatures high enough to melt or otherwise alter its contents. History Typology and chronology The form of the crucible has varied through time, with designs reflecting the process for which they are used, as well as regional variation. The earliest crucible forms derive from the sixth/fifth millennium B.C. in Eastern Europe and Iran. Chalcolithic Crucibles used for copper smelting were generally wide shallow vessels made from clay that lacks refractory properties which is similar to the types of clay used in other ceramics of the time. During the Chalcolithic period, crucibles were heated from the top by using blowpipes.Hauptmann A., 2003, ''Developments in copper Metallurgy During the Fourth and Third Millennia B.C. at Feinan'', Jorda ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boston University
Boston University (BU) is a private research university in Boston, Massachusetts. The university is nonsectarian, but has a historical affiliation with the United Methodist Church. It was founded in 1839 by Methodists with its original campus in Newbury, Vermont, before moving to Boston in 1867. The university now has more than 4,000 faculty members and nearly 34,000 students, and is one of Boston's largest employers. It offers bachelor's degrees, master's degrees, doctorates, and medical, dental, business, and law degrees through 17 schools and colleges on three urban campuses. The main campus is situated along the Charles River in Boston's Fenway-Kenmore and Allston, Massachusetts, Allston neighborhoods, while the Boston University Medical Campus is located in Boston's South End, Boston, South End neighborhood. The Fenway campus houses the Wheelock College of Education and Human Development, formerly Wheelock College, which merged with BU in 2018. BU is a member of the Bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratigraphy
Stratigraphy is a branch of geology concerned with the study of rock (geology), rock layers (Stratum, strata) and layering (stratification). It is primarily used in the study of sedimentary rock, sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithostratigraphy (lithologic stratigraphy), biostratigraphy (biologic stratigraphy), and chronostratigraphy (stratigraphy by age). Historical development Catholic priest Nicholas Steno established the theoretical basis for stratigraphy when he introduced the law of superposition, the principle of original horizontality and the principle of lateral continuity in a 1669 work on the fossilization of organic remains in layers of sediment. The first practical large-scale application of stratigraphy was by William Smith (geologist), William Smith in the 1790s and early 19th century. Known as the "Father of English geology", Smith recognized the significance of Stratum, strata or rock layering and the importance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
