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Arisman
Arisman ( fa, اريسمان, also Romanized as Arīsmān and Erīsmān; also known as Azīsmān and Brīsmān) is a village in Emamzadeh Aqaali Abbas Rural District, Emamzadeh District, Natanz County, Isfahan Province, Iran. At the 2006 census, its population was 1,745, in 489 families. Ancient metallurgy At Arisman, some of the oldest evidence of silver production in the world has been found - such as the litharge fragments and cakes. This was taking place around 3600 BC. Arsenical copper production was also taking place.Nima Nezafati, Ernst Pernicka, Barbara Helwing, Dirk KirchnerAncient metallurgy at Arisman, central Iran; A reconsideration.Conference: The First Iran-German Symposium on Archaeometry, TABRIZIAU, November 1-4, 2016 The ore was mined from some polymetallic ore deposits in the same area. These deposits contain a mixture of copper, arsenic, lead, and silver. First, the ore was smelted, and then the second step of cupellation was used to separate arsenical copper an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tepe Sialk
Tepe Sialk ( fa, تپه سیلک) is a large ancient archeological site (a ''tepe'', "hill, tell (archaeology), tell") in a suburb of the city of Kashan, Isfahan Province, in central Iran, close to Fin Garden. The culture that inhabited this area has been linked to the Zayandeh River Culture. History A joint study between Iran's Cultural Heritage Organization, the Louvre, and the Institut Francais de Recherche en Iran also verifies the oldest settlements in Sialk to date to around 6000–5500 BC. The Sialk ziggurat was built around 3000 BC. Sialk, and the entire area around it, is thought to have originated as a result of the pristine large water sources nearby that still run today. The Cheshmeh ye Soleiman ("Solomon's Spring") has been bringing water to this area from nearby mountains for thousands of years. The Fin garden, built in its present form in the 17th century, is a popular tourist attraction. It is here that the kings of the Safavid dynasty would spend their vacations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iran Standard Time
Iran Standard Time (IRST) or Iran Time (IT) is the time zone used in Iran. Iran uses a UTC offset UTC+03:30. IRST is defined by the 52.5 degrees east meridian, the same meridian which defines the Iranian calendar and is the official meridian of Iran. Between 2005 and 2008, by decree of President Mahmoud Ahmadinejad, Iran did not observe daylight saving time (DST) (called ''Iran Daylight Time'' or ''IRDT''). It was reintroduced from 21 March 2008. On 21 September 2022, Iran abolished DST and now observes standard time year-round. Daylight Saving Time transitions The dates of DST transitions in Iran were based on the Solar Hijri calendar, the official calendar of Iran, which is in turn based on the March equinox (Nowruz) as determined by astronomical calculation at the meridian for Iran Standard Time (52.5°E or GMT+3.5h). This resulted in the unique situation wherein the dates of DST transitions didn't fall on the same weekday each year as they do in most other countries. DST st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cupellation
Cupellation is a refining process in metallurgy where ores or alloyed metals are treated under very high temperatures and have controlled operations to separate noble metals, like gold and silver, from base metals, like lead, copper, zinc, arsenic, antimony, or bismuth, present in the ore. The process is based on the principle that precious metals do not oxidise or react chemically, unlike base metals. When they are heated at high temperatures, the precious metals remain apart, and the others react, forming slags or other compounds.Bayley, J. 2008 Since the Early Bronze Age, the process was used to obtain silver from smelted lead ores.Rehren, Th., Eckstein, K. 2002 By the Middle Ages and the Renaissance, cupellation was one of the most common processes for refining precious metals. By then, fire assays were used for assaying minerals: testing fresh metals such as lead and recycled metals to know their purity for jewellery and coin making. Cupellation is still in use today.Hoover, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arsenical Copper
Arsenical copper contains up to 0.5% arsenic which, at elevated temperatures, imparts higher tensile strength and a reduced tendency to scaling. It is typically specified in boiler work, especially locomotive fireboxes. It also helps prevent embrittlement of oxygen free copper by bismuth, antimony and lead by the formation of complex oxides. Copper with a larger percentage of arsenic is called arsenical bronze, which can be work-hardened much harder than copper. See also *Arsenical bronze *Arsenical brass Brass is an alloy of copper (Cu) and zinc (Zn), in proportions which can be varied to achieve different mechanical, electrical, and chemical properties. It is a substitutional alloy: atoms of the two constituents may replace each other with ... References Copper alloys Steam boilers Coinage metals and alloys Arsenic {{alloy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Litharge
Litharge (from Greek lithargyros, lithos (stone) + argyros (silver) ''λιθάργυρος'') is one of the natural mineral forms of lead(II) oxide, PbO. Litharge is a secondary mineral which forms from the oxidation of galena ores. It forms as coatings and encrustations with internal tetragonal crystal structure. It is dimorphous with the orthorhombic form massicot. It forms soft (Mohs hardness of 2), red, greasy-appearing crusts with a very high specific gravity of 9.14–9.35. PbO may be prepared by heating lead metal in air at approximately 600 °C (lead melts at only 300 °C). At this temperature it is also the end product of heating of other lead oxides in air. This is often done with a set of bellows pumping air over molten lead and causing the oxidized product to slip or fall off the top into a receptacle, where it quickly solidifies in minute scales. :PbO2 –(293 °C)→ Pb12O19 –(351 °C)→ Pb12O17 –(375 °C)→ Pb3O4 –(605 °C)→ PbO Historical term ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iran
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmenistan to the north, by Afghanistan and Pakistan to the east, and by the Gulf of Oman and the Persian Gulf to the south. It covers an area of , making it the 17th-largest country. Iran has a population of 86 million, making it the 17th-most populous country in the world, and the second-largest in the Middle East. Its largest cities, in descending order, are the capital Tehran, Mashhad, Isfahan, Karaj, Shiraz, and Tabriz. The country is home to one of the world's oldest civilizations, beginning with the formation of the Elamite kingdoms in the fourth millennium BC. It was first unified by the Medes, an ancient Iranian people, in the seventh century BC, and reached its territorial height in the sixth century BC, when Cyrus the Great fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Romanize
Romanization or romanisation, in linguistics, is the conversion of text from a different writing system to the Roman (Latin) script, or a system for doing so. Methods of romanization include transliteration, for representing written text, and transcription, for representing the spoken word, and combinations of both. Transcription methods can be subdivided into ''phonemic transcription'', which records the phonemes or units of semantic meaning in speech, and more strict ''phonetic transcription'', which records speech sounds with precision. Methods There are many consistent or standardized romanization systems. They can be classified by their characteristics. A particular system’s characteristics may make it better-suited for various, sometimes contradictory applications, including document retrieval, linguistic analysis, easy readability, faithful representation of pronunciation. * Source, or donor language – A system may be tailored to romanize text from a particular lan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iran Daylight Time
Iran Standard Time (IRST) or Iran Time (IT) is the time zone used in Iran. Iran uses a UTC offset UTC+03:30. IRST is defined by the 52.5 degrees east meridian, the same meridian which defines the Iranian calendar and is the official meridian of Iran. Between 2005 and 2008, by decree of President Mahmoud Ahmadinejad, Iran did not observe daylight saving time (DST) (called ''Iran Daylight Time'' or ''IRDT''). It was reintroduced from 21 March 2008. On 21 September 2022, Iran abolished DST and now observes standard time year-round. Daylight Saving Time transitions The dates of DST transitions in Iran were based on the Solar Hijri calendar, the official calendar of Iran, which is in turn based on the March equinox (Nowruz) as determined by astronomical calculation at the meridian for Iran Standard Time (52.5°E or GMT+3.5h). This resulted in the unique situation wherein the dates of DST transitions didn't fall on the same weekday each year as they do in most other countries. DST st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Countries
The following is a list providing an overview of sovereign states around the world with information on their status and recognition of their sovereignty. The 206 listed states can be divided into three categories based on membership within the United Nations System: 193 UN member states, 2 UN General Assembly non-member observer states, and 11 other states. The ''sovereignty dispute'' column indicates states having undisputed sovereignty (188 states, of which there are 187 UN member states and 1 UN General Assembly non-member observer state), states having disputed sovereignty (16 states, of which there are 6 UN member states, 1 UN General Assembly non-member observer state, and 9 de facto states), and states having a special political status (2 states, both in free association with New Zealand). Compiling a list such as this can be a complicated and controversial process, as there is no definition that is binding on all the members of the community of nations concernin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Provinces Of Iran
Iran is subdivided into thirty-one provinces ( fa, استان ''ostân''), each governed from a local centre, usually the largest local city, which is called the capital (Persian: , '' markaz'') of that province. The provincial authority is headed by a governor-general (Persian: ''ostândâr''), who is appointed by the Minister of the Interior subject to approval of the cabinet. Modern history Iran has held its modern territory since the Treaty of Paris in 1857. From 1906 until 1950, Iran was divided into twelve provinces: Ardalan, Azerbaijan, Baluchestan, Fars, Gilan, Araq-e Ajam, Khorasan, Khuzestan, Kerman, Larestan, Lorestan, and Mazandaran. In 1950, Iran was reorganized to form ten numbered provinces with subordinate governorates: Gilan; Mazandaran; East Azerbaijan; West Azerbaijan; Kermanshah; Khuzestan; Fars; Kerman; Khorasan; Isfahan. Iran has had a historical claim to Bahrain as its 14th province: Bahrain Province, until 1971 under British colonial o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rural Districts Of Iran
Dehestan ( fa, دهستان, lit=rural district, also Romanized as "dehestān") is a type of administrative division of Iran. It is above the village and under the bakhsh A ( fa, بخش, also romanized as ) is a third-level administrative division of Iran. While sometimes translated as "county," it is more accurately translated as "district," similar to a township in the United States or a district of En .... , there were 2,400 dehestans in Iran. References Subdivisions of Iran Types of administrative division {{Iran-gov-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emamzadeh District
Emamzadeh District ( fa, بخش امامزاده) is a district (bakhsh) in Natanz County, Isfahan Province, Iran. At the 2006 census, its population was 23,211, in 5,994 families. The District has two cities: Badrud and Khaledabad. The District has two rural districts (''dehestan''): Emamzadeh Aqaali Abbas Rural District and Khaledabad Rural District , native_name_lang = fa , settlement_type = Rural District , image_skyline = , imagesize = , image_alt = , image_caption = , image_flag = , flag_alt .... References Natanz County Districts of Isfahan Province {{Natanz-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
