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Cheirosiphon
Greek fire was an incendiary weapon used by the Eastern Roman Empire beginning . Used to set fire to enemy ships, it consisted of a combustible compound emitted by a flame-throwing weapon. Some historians believe it could be ignited on contact with water, and was probably based on naphtha and quicklime. The Byzantines typically used it in naval battles to great effect, as it could continue burning while floating on water. The technological advantage it provided was responsible for many key Byzantine military victories, most notably the salvation of Constantinople from the first and second Arab sieges, thus securing the empire's survival. The impression made by Greek fire on the western European Crusaders was such that the name was applied to any sort of incendiary weapon, including those used by Arabs, the Chinese, and the Mongols. However, these mixtures used formulas different from that of Byzantine Greek fire, which was a closely guarded state secret. Byzantines also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium Phosphide
Calcium phosphide (CP) is the inorganic compound with the formula Ca3P2. It is one of several phosphides of calcium, being described as the salt-like material composed of Ca2+ and P3−. Other, more exotic calcium phosphides have the formula CaP, CaP3, Ca2P2, and Ca5P8. Ca3P2 has the appearance of red-brown crystalline powder or grey lumps. Its trade name is Photophor for the incendiary use or Polytanol for the use as rodenticide. Preparation and structure It may be formed by reaction of the elements, but it is more commonly prepared by carbothermal reduction of calcium phosphate: :Ca3(PO4)2 + 8 C → Ca3P2 + 8 CO The structure of the room temperature form of Ca3P2 has not been confirmed by X-ray crystallography. A high temperature phase has been characterized by Rietveld refinement. Ca2+ centers are octahedral. Uses Metal phosphides are used as a rodenticide. A mixture of food and calcium phosphide is left where the rodents can eat it. The acid in the digestive system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Athens
Athens ( ; el, Αθήνα, Athína ; grc, Ἀθῆναι, Athênai (pl.) ) is both the capital and largest city of Greece. With a population close to four million, it is also the seventh largest city in the European Union. Athens dominates and is the capital of the Attica region and is one of the world's oldest cities, with its recorded history spanning over 3,400 years and its earliest human presence beginning somewhere between the 11th and 7th millennia BC. Classical Athens was a powerful city-state. It was a centre for the arts, learning and philosophy, and the home of Plato's Academy and Aristotle's Lyceum. It is widely referred to as the cradle of Western civilization and the birthplace of democracy, largely because of its cultural and political influence on the European continent—particularly Ancient Rome. In modern times, Athens is a large cosmopolitan metropolis and central to economic, financial, industrial, maritime, political and cultural life in Gre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Malalas
John Malalas ( el, , ''Iōánnēs Malálas''; – 578) was a Byzantine chronicler from Antioch (now Antakya, Turkey). Life Malalas was of Syrian descent, and he was a native speaker of Syriac who learned how to write in Greek later in his life. The name ''Malalas'' probably derived from the Aramaic word (ܡܰܠܳܠܰܐ ''malolo'') for "rhetor", "orator"; it is first applied to him by John of Damascus. The alternative form ''Malelas'' is later, first appearing in Constantine VII. Malalas was educated in Antioch, and probably was a jurist there, but moved to Constantinople at some point in Justinian I's reign (perhaps after the Persian sack of Antioch in 540); all we know of his travels from his own hand are visits to Thessalonica and Paneas. Writing He wrote a ''Chronographia'' () in 18 books, the beginning and the end of which are lost. In its present state it begins with the mythical history of Egypt and ends with the expedition to Roman Africa under the tribune ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anastasius I (emperor)
Anastasius I Dicorus ( grc-gre, Ἀναστάσιος, Anastásios; – 9 July 518) was Eastern Roman emperor from 491 to 518. A career civil servant, he came to the throne at the age of 61 after being chosen by the wife of his predecessor, Zeno. His reign was characterised by reforms and improvements in the government, finances, economy, and bureaucracy of the Empire. He is noted for leaving the empire with a stable government, reinvigorated monetary economy and a sizeable budget surplus, which allowed the Empire to pursue more ambitious policies under his successors, most notably Justinian I. Since many of Anastasius' reforms proved long-lasting, his influence over the Empire endured for many centuries. Anastasius was a Miaphysite and his personal religious tendencies caused tensions throughout his reign in the Empire which was becoming increasingly divided along religious lines. He is venerated as a saint by the Syriac Orthodox Church on 29 July. Early life and family A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resin
In polymer chemistry and materials science, resin is a solid or highly viscous substance of plant or synthetic origin that is typically convertible into polymers. Resins are usually mixtures of organic compounds. This article focuses on naturally occurring resins. Plants secrete resins for their protective benefits in response to injury. The resin protects the plant from insects and pathogens. Resins confound a wide range of herbivores, insects, and pathogens, while the volatile phenolic compounds may attract benefactors such as parasitoids or predators of the herbivores that attack the plant. Composition Most plant resins are composed of terpenes. Specific components are alpha-pinene, beta-pinene, delta-3 carene, and sabinene, the monocyclic terpenes limonene and terpinolene, and smaller amounts of the tricyclic sesquiterpenes, longifolene, caryophyllene, and delta-cadinene. Some resins also contain a high proportion of resin acids. Rosins on the other hand are less ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sextus Julius Africanus
Sextus Julius Africanus (c. 160 – c. 240; Greek: Σέξτος Ἰούλιος ὁ Ἀφρικανός or ὁ Λίβυς) was a Christian traveler and historian of the late second and early third centuries. He is important chiefly because of his influence on Eusebius, on all the later writers of Church history among the Church Fathers, and on the whole Greek school of chroniclers. Biography The Suda claims Africanus was a "Libyan philosopher", while Gelzer considers him of Roman and Ethiopian descent. Julius called himself a native of Jerusalem – which some scholars consider his birthplace – and lived at the neighbouring Emmaus. His chronicle indicates his familiarity with the topography of historic Judea. Little of Africanus's life is known and all dates are uncertain. One tradition places him under the Emperor Gordianus III (238–244), others mention him under Severus Alexander (222–235). He appears to have known Abgar VIII (176–213). Africa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bellows
A bellows or pair of bellows is a device constructed to furnish a strong blast of air. The simplest type consists of a flexible bag comprising a pair of rigid boards with handles joined by flexible leather sides enclosing an approximately airtight cavity which can be expanded and contracted by operating the handles, and fitted with a valve allowing air to fill the cavity when expanded, and with a tube through which the air is forced out in a stream when the cavity is compressed. xford English Dictionary, 2nd ed: bellows/ref> It has many applications, in particular blowing on a fire to supply it with air. The term "bellows" is used by extension for a flexible bag whose volume can be changed by compression or expansion, but not used to deliver air. For example, the light-tight (but not airtight) bag allowing the distance between the lens and film of a folding photographic camera to be varied is called a bellows. Etymology "Bellows" is only used in plural. The Old English name ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battle Of Delium
The Battle of Delium (or Delion, a city in Boeotia) took place in 424 BC, during the Peloponnesian War. It was fought between the Athenians and the Boeotians, who were allies of the Spartans, and ended with the siege of Delium in the following weeks. Prelude In 424 BC, the Athenian generals Demosthenes and Hippocrates planned to invade Boeotia. Demosthenes mistakenly sailed too early and landed at Siphae, where his plans were betrayed by a Phocian named Nicomachus. As Hippocrates had not yet arrived, Demosthenes could not attack and was forced to withdraw. Hippocrates eventually arrived in Boeotia with an Athenian army and began to fortify the temple at Delium. After five days, the fortifications were complete, and Hippocrates set up a garrison and sent the rest of his army back to Athens. At the same time, the Boeotians gathered their army to challenge Hippocrates, but when they saw that the Athenians were leaving, many of them thought that it was pointless to attack. Pagondas o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thucydides
Thucydides (; grc, , }; BC) was an Athenian historian and general. His ''History of the Peloponnesian War'' recounts the fifth-century BC war between Sparta and Athens until the year 411 BC. Thucydides has been dubbed the father of "scientific history" by those who accept his claims to have applied strict standards of impartiality and evidence-gathering and analysis of cause and effect, without reference to intervention by the gods, as outlined in his introduction to his work. He also has been called the father of the school of political realism, which views the political behavior of individuals and the subsequent outcomes of relations between states as ultimately mediated by, and constructed upon, fear and self-interest. His text is still studied at universities and military colleges worldwide. The Melian dialogue is regarded as a seminal work of international relations theory, while his version of Pericles' Funeral Oration is widely studied by political theorists, historian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neo-Assyrian Empire
The Neo-Assyrian Empire was the fourth and penultimate stage of ancient Assyrian history and the final and greatest phase of Assyria as an independent state. Beginning with the accession of Adad-nirari II in 911 BC, the Neo-Assyrian Empire grew to dominate the ancient Near East throughout much of the 8th and 7th centuries BC, becoming the largest empire in history up to that point. Because of its geopolitical dominance and ideology based in world domination, the Neo-Assyrian Empire is by many researchers regarded to have been the first world empire in history. At its height, the empire was the strongest military power in the world and ruled over all of Mesopotamia, the Levant and Egypt, as well as portions of Anatolia, Arabia and modern-day Iran and Armenia. The early Neo-Assyrian kings were chiefly concerned with restoring Assyrian control over much of northern Mesopotamia and Syria, since significant portions of the preceding Middle Assyrian Empire had been lost during a long ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bitumen
Asphalt, also known as bitumen (, ), is a sticky, black, highly viscous liquid or semi-solid form of petroleum. It may be found in natural deposits or may be a refined product, and is classed as a pitch. Before the 20th century, the term asphaltum was also used. Full text at Internet Archive (archive.org) The word is derived from the Ancient Greek ἄσφαλτος ''ásphaltos''. The largest natural deposit of asphalt in the world, estimated to contain 10 million tons, is the Pitch Lake located in La Brea in southwest Trinidad (Antilles island located on the northeastern coast of Venezuela), within the Siparia Regional Corporation. The primary use (70%) of asphalt is in road construction, where it is used as the glue or binder mixed with aggregate particles to create asphalt concrete. Its other main uses are for bituminous waterproofing products, including production of roofing felt and for sealing flat roofs. In material sciences and engineering, the terms "asphalt" an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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