You're using an outdated browser. Please upgrade to a modern browser for the best experience.
Topic Review
Hot Dry Rock Geothermal Energy
Hot dry rock (HDR) is an extremely abundant source of geothermal energy that is difficult to access. A vast store of thermal energy is contained within hot – but essentially dry and impervious crystalline basement rocks found almost everywhere deep beneath Earth's surface. A concept for the extraction of useful amounts of geothermal energy from HDR originated at the Los Alamos National Laboratory in 1970, and Laboratory researchers were awarded a U.S. patent covering it. This technology has been tested extensively with multiple deep wells drilled in several field areas around world including the USA, Japan, Australia, France, and the UK and investment of billions of research funds. It continues to be the focus along with a related technique called EGS for sizable government-led research studies involving costly deep drilling and rock studies. Thermal energy has been recovered in reasonably sustainable tests over periods of years and in some cases electrical power generation was also achieved. However no commercial projects are ongoing or likely due to the high cost and limited capacity of the engineered reservoirs, associated wells, and pumping systems. Commonly tests have opened just one or more fractures such that the reservoir surface heat exchange areas are limited. For this technology to successfully compete with other energy sources, drilling costs would have to drop drastically or new approaches that result in much more extensive, complex, and higher rate flow paths through actual fracture networks would have to be established. The enthusiasim evident here on Wikipedia and in the research community is justified by the vast extent of the energy supply and the low environmental impact of the method however significant breakthroughs will be required to make this a commercial energy resource.
  • 6.9K
  • 30 Oct 2022
Topic Review
Normal Gravity Formula
Normal gravity formulas are mathematical expressions, with which the free-fall acceleration at a point in vicinity to the surface of the earth can be estimated. Along with the mass (known or predicted) of a body, the weight is calculated.
  • 6.6K
  • 10 Nov 2022
Topic Review
Indian Remote Sensing Programme
India's remote sensing program was developed with the idea of applying space technologies for the benefit of human kind and the development of the country. The program involved the development of three principal capabilities. The first was to design, build and launch satellites to a sun synchronous orbit. The second was to establish and operate ground stations for spacecraft control, data transfer along with data processing and archival. The third was to use the data obtained for various applications on the ground.
  • 6.5K
  • 17 Nov 2022
Topic Review
Sandstone
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) mineral particles or rock fragments. Most sandstone is composed of quartz or feldspar (both silicates) because they are the most resistant minerals to weathering processes at the Earth's surface, as seen in Bowen's reaction series. Like uncemented sand, sandstone may be any color due to impurities within the minerals, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black. Since sandstone beds often form highly visible cliffs and other topographic features, certain colors of sandstone have been strongly identified with certain regions. Rock formations that are primarily composed of sandstone usually allow the percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs. Fine-grained aquifers, such as sandstones, are better able to filter out pollutants from the surface than are rocks with cracks and crevices, such as limestone or other rocks fractured by seismic activity. Quartz-bearing sandstone can be converted into quartzite through metamorphism, usually related to tectonic compression within orogenic belts.
  • 6.0K
  • 15 Nov 2022
Topic Review
Bush Encroachment
Bush encroachment (also shrub encroachment, woody encroachment, bush thickening, woody plant proliferation) is a natural phenomenon characterised by the increase in density of woody plants, bushes and shrubs, at the expense of the herbaceous layer, grasses and forbs. It predominantly occurs in grasslands, savannas and woodlands and can cause biome shifts from open grasslands and savannas to closed woodlands. The term bush encroachment refers to the expansion of native plants and not the spread of alien invasive species. It is thus defined by plant density, not species. Bush encroachment is often considered an ecological regime shift and can be a symptom of land degradation. Its causes include land use intensification, such as high grazing pressure and the suppression of wildfires. Climate change is found to be an accelerating factor for woody encroachment. The impact of bush encroachment is highly context specific. It is often found to have severe negative consequences on key ecosystem services, especially biodiversity, animal habitat, land productivity and groundwater recharge. Across rangelands, woody encroachment has led to significant declines of productivity, threatening the livelihoods of affected land users. The phenomenon is observed across different ecosystems and with different characteristics and intensities globally. Various countries actively counter woody encroachment, through adapted grassland management practices and targeted bush thinning. In some cases, areas affected by woody encroachment are classified as carbon sinks and form part of national greenhouse gas inventories. However, carbon sequestration effects of woody encroachment are highly context specific and still insufficiently researched.
  • 5.8K
  • 08 Nov 2022
Topic Review
Reindeer Distribution
The reindeer is a widespread and numerous species in the northern Holarctic, being present in both tundra and taiga (boreal forest). Originally, the reindeer was found in Scandinavia, eastern Europe, Russia , Mongolia, and northern China north of the 50th latitude. In North America, it was found in Canada , Alaska (United States ), and the northern contiguous USA from Washington to Maine. In the 19th century, it was apparently still present in southern Idaho. It also occurred naturally on Sakhalin, Greenland, and probably even in historical times in Ireland. During the late Pleistocene era, reindeer were found further south, such as at Nevada, Tennessee , and Alabama in North America and Spain in Europe. Today, wild reindeer have disappeared from many areas within this large historical range, especially from the southern parts, where it vanished almost everywhere. Populations of wild reindeer are still found in Norway , Finland , Siberia, Greenland, Alaska, and Canada . Domesticated reindeer are mostly found in northern Fennoscandia and Russia, with a herd of approximately 150–170 semi-domesticated reindeer living around the Cairngorms region in Scotland. The last remaining wild tundra reindeer in Europe are found in portions of southern Norway . A few reindeer from Norway were introduced to the South Atlantic island of South Georgia in the beginning of the 20th century. The South Georgian reindeer totaled some estimated 2600 animals in two distinct herds separated by glaciers. Although the flag and the coat of arms of the territory contain an image of a reindeer, they were eradicated from 2013 to 2017 because of the environmental damage they caused. Around 4000 reindeer have been introduced into the French sub-Antarctic archipelago of Kerguelen Islands. East Iceland has a small herd of about 2500–3000 animals. Caribou and reindeer numbers have fluctuated historically, but many herds are in decline across their range. This global decline is linked to climate change for northern, migratory caribou and reindeer herds and industrial disturbance of caribou habitat for sedentary, non-migratory herds.
  • 5.8K
  • 28 Nov 2022
Topic Review
Muslim World
The terms Muslim world and Islamic world commonly refer to the Islamic community, which is also known as the Ummah. This consists of all those who adhere to the religions beliefs and laws of Islam, or to societies where Islam is practiced. In a modern geopolitical sense, these terms refer to countries where Islam is widespread, although there are no agreed criteria for inclusion. The term Muslim-majority countries is an alternative often used for the latter sense. The history of the Muslim world spans about 1,400 years and includes a variety of socio-political developments, as well as advances in the arts, science, philosophy, and technology, particularly during the Islamic Golden Age. All Muslims look for guidance to the Quran and believe in the prophetic mission of the Islamic prophet Muhammad, but disagreements on other matters have led to the appearance of different religious schools of thought and sects within Islam. In the modern era, most of the Muslim world came under European colonial domination. The nation states that emerged in the post-colonial era have adopted a variety of political and economic models, and they have been affected by secular and as well as religious trends. (As of 2013), the combined GDP (nominal) of 49 Muslim majority countries was US$5.7 trillion, (As of 2016), they contributed 8% of the world's total. As of 2015, 1.8 billion or about 24.1% of the world population are Muslims. By the percentage of the total population in a region considering themselves Muslim, 91% in the Middle East-North Africa (MENA), 89% in Central Asia, 40% in Southeast Asia, 31% in South Asia, 30% in Sub-Saharan Africa, 25% in Asia–Oceania, around 6% in Europe, and 1% in the Americas. Most Muslims are of one of two denominations: Sunni Islam (85-90%) and Shia (10-15%), However, other denominations exist in pockets, such as Ibadi (primarily in Oman). About 13% of Muslims live in Indonesia, the largest Muslim-majority country; 31% of Muslims live in South Asia, the largest population of Muslims in the world; 20% in the Middle East–North Africa, where it is the dominant religion; and 15% in Sub-Saharan Africa and West Africa. Muslims are the overwhelming majority in Central Asia, the majority in the Caucasus and widespread in Southeast Asia. India is the country with the largest Muslim population outside Muslim-majority countries. Sizeable Muslim communities are also found in the Americas, China, and Europe. Islam is the fastest-growing major religion in the world.
  • 5.7K
  • 26 Oct 2022
Topic Review
History, Preparation, Characterization and Applications of Moisturizers
Moisturizers are one of the most widely used preparations in cosmetics and have been extensively used to soften the skin for consumers. Cosmetically, moisturizers make the skin smooth by the mechanism of increasing the water content in the stratum corneum, hence exerting its most vital action, which is moisturizing action and maintaining a normal skin pH.
  • 5.4K
  • 13 Jul 2022
Topic Review
Geodetic Datum
A geodetic datum or geodetic system (also: geodetic reference datum or geodetic reference system) is a coordinate system, and a set of reference points, used for locating places on the Earth (or similar objects). An approximate definition of sea level is the datum WGS 84, an ellipsoid, whereas a more accurate definition is Earth Gravitational Model 2008 (EGM2008), using at least 2,159 spherical harmonics. Other datums are defined for other areas or at other times; ED50 was defined in 1950 over Europe and differs from WGS 84 by a few hundred meters depending on where in Europe you look. Mars has no oceans and so no sea level, but at least two martian datums have been used to locate places there. Datums are used in geodesy, navigation, and surveying by cartographers and satellite navigation systems to translate positions indicated on maps (paper or digital) to their real position on Earth. Each starts with an ellipsoid (stretched sphere), and then defines latitude, longitude and altitude coordinates. One or more locations on the Earth's surface are chosen as anchor "base-points". The difference in co-ordinates between datums is commonly referred to as datum shift. The datum shift between two particular datums can vary from one place to another within one country or region, and can be anything from zero to hundreds of meters (or several kilometers for some remote islands). The North Pole, South Pole and Equator will be in different positions on different datums, so True North will be slightly different. Different datums use different interpolations for the precise shape and size of the Earth (reference ellipsoids). Because the Earth is an imperfect ellipsoid, localised datums can give a more accurate representation of the area of coverage than WGS 84. OSGB36, for example, is a better approximation to the geoid covering the British Isles than the global WGS 84 ellipsoid. However, as the benefits of a global system outweigh the greater accuracy, the global WGS 84 datum is becoming increasingly adopted. Horizontal datums are used for describing a point on the Earth's surface, in latitude and longitude or another coordinate system. Vertical datums measure elevations or depths.
  • 5.4K
  • 24 Nov 2022
Topic Review
Transcaucasia
Transcaucasia, also known as the South Caucasus, is a geographical region on the border of Eastern Europe and Western Asia, straddling the southern Caucasus Mountains. Transcaucasia roughly corresponds to modern Armenia, Georgia and Azerbaijan, and are sometimes collectivelly known as the Caucasian States. The total area of these countries measures about 186,100 square kilometres (71,850 square miles). Transcaucasia and Ciscaucasia (North Caucasus) together comprise the larger Caucasus geographical region that divides Eurasia.
  • 5.2K
  • 23 Nov 2022
Topic Review
First Bulgarian Empire
The First Bulgarian Empire (Old Bulgarian: ц︢рьство бл︢гарское, ts'rstvo bl'garskoe) was a medieval Bulgarian state that existed in Southeastern Europe between the 7th and 11th centuries AD. It was founded in 681 when Bulgar tribes led by Asparuh moved to the northeastern Balkans. There they secured Byzantine recognition of their right to settle south of the Danube by defeating – possibly with the help of local South Slavic tribes – the Byzantine army led by Constantine IV. At the height of its power, Bulgaria spread from the Danube Bend to the Black Sea and from the Dnieper River to the Adriatic Sea. As the state solidified its position in the Balkans, it entered into a centuries-long interaction, sometimes friendly and sometimes hostile, with the Byzantine Empire. Bulgaria emerged as Byzantium's chief antagonist to its north, resulting in several wars. The two powers also enjoyed periods of peace and alliance, most notably during the Second Arab siege of Constantinople, where the Bulgarian army broke the siege and destroyed the Arab army, thus preventing an Arab invasion of Southeastern Europe. Byzantium had a strong cultural influence on Bulgaria, which also led to the eventual adoption of Christianity in 864. After the disintegration of the Avar Khaganate, the country expanded its territory northwest to the Pannonian Plain. Later the Bulgarians confronted the advance of the Pechenegs and Cumans, and achieved a decisive victory over the Magyars, forcing them to establish themselves permanently in Pannonia. During the late 9th and early 10th centuries, Simeon I achieved a string of victories over the Byzantines. Thereafter, he was recognized with the title of Emperor, and proceeded to expand the state to its greatest extent. After the annihilation of the Byzantine army in the battle of Anchialus in 917, the Bulgarians laid siege to Constantinople in 923 and 924. The Byzantines, however, eventually recovered, and in 1014, under Basil II, inflicted a crushing defeat on the Bulgarians at the Battle of Kleidion. By 1018, the last Bulgarian strongholds had surrendered to the Byzantine Empire, and the First Bulgarian Empire had ceased to exist. It was succeeded by the Second Bulgarian Empire in 1185. After the adoption of Christianity, Bulgaria became the cultural center of Slavic Europe. Its leading cultural position was further consolidated with the invention of the Glagolitic and Early Cyrillic alphabets shortly after in the capital Preslav, and literature produced in Old Bulgarian soon began spreading north. Old Bulgarian became the lingua franca of much of Eastern Europe and it came to be known as Old Church Slavonic. In 927, the fully independent Bulgarian Patriarchate was officially recognized. The ruling Bulgars and other non-Slavic tribes in the empire gradually mixed and adopted the prevailing Slavic language, thus gradually forming the Bulgarian nation from the 7th century to the 9th century. Since the late 9th century, the names Bulgarians and Bulgarian gained prevalence and became permanent designations for the local population, both in literature and in common parlance. The development of Old Church Slavonic literacy had the effect of preventing the assimilation of the South Slavs into neighbouring cultures, while stimulating the formation of a distinct Bulgarian identity.
  • 5.2K
  • 25 Oct 2022
Topic Review
ISO Standards for Trailer Connectors
A number of ISO standards cover trailer connectors, the electrical connectors between vehicles and the trailers they tow that provide a means of control for the trailers. These are listed below, with notes on significant deviations from them that can cause problems.
  • 5.2K
  • 07 Nov 2022
Topic Review
Barcelona
Barcelona (/ˌbɑːrsəˈloʊnə/ BAR-sə-LOH-nə, Catalan: [bəɾsəˈlonə], Spanish: [baɾθeˈlona]) is a city in Spain . It is the capital and largest city of Catalonia, as well as the second most populous municipality of Spain. With a population of 1.6 million within city limits, its urban area extends to numerous neighbouring municipalities within the Province of Barcelona and is home to around 4.8 million people, making it the sixth most populous urban area in the European Union after Paris, London, Madrid, the Ruhr area and Milan. It is one of the largest metropolises on the Mediterranean Sea, located on the coast between the mouths of the rivers Llobregat and Besòs, and bounded to the west by the Serra de Collserola mountain range, the tallest peak of which is 512 metres (1,680 feet) high. Founded as a Roman city, in the Middle Ages Barcelona became the capital of the County of Barcelona. After merging with the Kingdom of Aragon, Barcelona continued to be an important city in the Crown of Aragon as an economic and administrative centre of this Crown and the capital of the Principality of Catalonia. Barcelona has a rich cultural heritage and is today an important cultural centre and a major tourist destination. Particularly renowned are the architectural works of Antoni Gaudí and Lluís Domènech i Montaner, which have been designated UNESCO World Heritage Sites. The headquarters of the Union for the Mediterranean are located in Barcelona. The city is known for hosting the 1992 Summer Olympics as well as world-class conferences and expositions and also many international sport tournaments. Barcelona is one of the world's leading tourist, economic, trade fair and cultural centres, and its influence in commerce, education, entertainment, media, fashion, science, and the arts all contribute to its status as one of the world's major global cities. It is a major cultural and economic centre in southwestern Europe, 24th in the world (before Zürich, after Frankfurt) and a financial centre. In 2008 it was the fourth most economically powerful city by GDP in the European Union and 35th in the world with GDP amounting to €177 billion. In 2012 Barcelona had a GDP of $170 billion; and it was leading Spain in employment rate in that moment. In 2009 the city was ranked Europe's third and one of the world's most successful as a city brand. In the same year the city was ranked Europe's fourth best city for business and fastest improving European city, with growth improved by 17% per year, and the city has been experiencing strong and renewed growth for the past three years. Since 2011 Barcelona has been a leading smart city in Europe. Barcelona is a transport hub, with the Port of Barcelona being one of Europe's principal seaports and busiest European passenger port, an international airport, Barcelona–El Prat Airport, which handles over 40 million passengers per year, an extensive motorway network, and a high-speed rail line with a link to France and the rest of Europe.
  • 5.2K
  • 16 Nov 2022
Topic Review
Geography and Cartography in Medieval Islam
Medieval Islamic geography and cartography refer to the study of geography and cartography in the Muslim world during the Islamic Golden Age (variously dated between the 8th century and 16th century). Muslim scholars made advances to the mapmaking traditions of earlier cultures, particularly the Hellenistic geographers Ptolemy and Marinus of Tyre,:193 combined with what explorers and merchants learned in their travels across the Old World (Afro-Eurasia). Islamic geography had three major fields: exploration and navigation, physical geography, and cartography and mathematical geography. Islamic geography reached its apex with Muhammad al-Idrisi in the 12th century.
  • 5.1K
  • 26 Oct 2022
Topic Review
Golan Heights
The Golan Heights (Arabic: هَضْبَةُ الْجَوْلَانِ or Arabic: مُرْتَفَعَاتُ الْجَوْلَانِ, Hebrew: רמת הגולן‎, romanized: Ramat HaGolan), or simply the Golan, is a region in the Levant spanning about 1,800 square kilometres (690 sq mi). The region defined as the Golan Heights differs between disciplines: as a geological and biogeographical region, the term refers to a basaltic plateau bordered by the Yarmouk River in the south, the Sea of Galilee and Hula Valley in the west, the Anti-Lebanon with Mount Hermon in the north and Wadi Raqqad in the east. As a geopolitical region, it refers to the border region captured from Syria by Israel during the Six-Day War of 1967; the territory has been occupied by the latter since then and was subject to a de facto Israeli annexation in 1981. This region includes the western two-thirds of the geological Golan Heights and the Israeli-occupied part of Mount Hermon. The earliest evidence of human habitation on the Golan dates to the Upper Paleolithic period. According to the Bible, an Amorite kingdom in Bashan was conquered by the Israelites during the reign of King Og. Throughout the Biblical period, the Golan was "the focus of a power struggle between the kings of Israel and the Aramaeans who were based near modern-day Damascus." After Assyrian and Babylonian rule, the region came under the domination of Persia, following which Jews were freed from Babylonian captivity and allowed to return and resettle in the land. The Itureans, an Arab or Aramaic people, settled in the area in the 2nd century BCE. In the 16th century, the Golan was conquered by the Ottoman Empire. Within Ottoman Syria, the Golan was part of the Syria Vilayet. The area later became part of the French Mandate in Syria and the State of Damascus. When the mandate terminated in 1946, it became part of the newly independent Syrian Arab Republic. By the late-19th century, the Golan Heights was inhabited mostly by colonized peasants (fellaḥîn), Bedouin Arabs, Druze, Turkmen, and Circassians. Since the Six-Day War of 1967, the western two-thirds of the Golan Heights has been occupied and administered by Israel, whereas the eastern third remains under the control of Syria. Following the war, Syria dismissed any negotiations with Israel as part of the Khartoum Resolution at the 1967 Arab League summit. Construction of Israeli settlements began in the remainder of the territory held by Israel, which was under a military administration until the Knesset passed the Golan Heights Law in 1981, which applied Israeli law to the territory; the move has been described as an annexation. The Golan Heights Law was condemned by the United Nations Security Council in Resolution 497, which stated that "the Israeli decision to impose its laws, jurisdiction, and administration in the occupied Syrian Golan Heights is null and void and without international legal effect", and Resolution 242, which emphasizes the "inadmissibility of the acquisition of territory by war". Israel maintains it has a right to retain the Golan, also citing the text of Resolution 242, which calls for "secure and recognized boundaries free from threats or acts of force". After the onset of the Syrian Civil War in 2011, control of the Syrian-administered part of the Golan Heights was split between the state government and Syrian opposition forces, with the United Nations Disengagement Observer Force (UNDOF) maintaining a 266 km2 (103 sq mi) buffer zone in between to help implement the Israeli–Syrian ceasefire across the Purple Line. From 2012 to 2018, the eastern half of the Golan Heights became a scene of repeated battles between the Syrian Army, rebel factions of the Syrian opposition (including the United States -backed Southern Front) as well as various jihadist organizations such as al-Nusra Front and the Islamic State of Iraq and the Levant-affiliated Khalid ibn al-Walid Army. In July 2018, the Syrian government regained full control over the eastern Golan Heights. On 25 March 2019, then-President of the United States Donald Trump proclaimed US recognition of the Golan Heights as a part of the State of Israel, making it the first country to do so. The 28 member states of the European Union declared in turn that they do not recognize Israeli sovereignty, and several experts on international law reiterated that the principle remains that land gained by either defensive or offensive wars cannot be legally annexed under international law.
  • 5.0K
  • 18 Nov 2022
Topic Review
List of Research Stations in the Arctic
A number of governments maintain permanent research stations in the Arctic. Also known as Arctic bases, polar stations or ice stations, these bases are widely distributed across the northern polar region of the earth. Historically few research stations have been permanent. Most of them were temporary, being abandoned after the completion of the project or owing to lack of funding to continue the research. Some of these were military or intelligence stations (listening posts) created as a result of the proximity of the U.S. and Soviet Union to each other's landmass across the polar region. Ice stations are constructed on land or on ice that rests on land, while others are drifting ice stations built on the sea ice of the high latitudes of the Arctic Ocean.
  • 5.0K
  • 30 Nov 2022
Topic Review
Kiev
Kiev or Kyiv (Ukrainian: Київ; Russian: Киев, romanized: Kiyev) is the capital and most populous city of Ukraine . It is in north-central Ukraine along the Dnieper River. Its population in July 2015 was 2,887,974 (though higher estimated numbers have been cited in the press), making Kiev the seventh-most populous city in Europe. Kiev is an important industrial, scientific, educational and cultural center of Eastern Europe. It is home to many high-tech industries, higher education institutions, and historical landmarks. The city has an extensive system of public transport and infrastructure, including the Kiev Metro. The city's name is said to derive from the name of Kyi, one of its four legendary founders. During its history, Kiev, one of the oldest cities in Eastern Europe, passed through several stages of prominence and obscurity. The city probably existed as a commercial center as early as the 5th century. A Slavic settlement on the great trade route between Scandinavia and Constantinople, Kiev was a tributary of the Khazars, until its capture by the Varangians (Vikings) in the mid-9th century. Under Varangian rule, the city became a capital of the Kievan Rus', the first East Slavic state. Completely destroyed during the Mongol invasions in 1240, the city lost most of its influence for the centuries to come. It was a provincial capital of marginal importance in the outskirts of the territories controlled by its powerful neighbours, first Lithuania, then Poland and Russia. The city prospered again during the Russian Empire's Industrial Revolution in the late 19th century. In 1918, after the Ukrainian National Republic declared independence from Soviet Russia, Kiev became its capital. From 1921 onwards Kiev was a city of Soviet Ukraine, which was proclaimed by the Red Army, and, from 1934, Kiev was its capital. The city was almost completely ruined during World War II but quickly recovered in the postwar years, remaining the Soviet Union's third-largest city. Following the collapse of the Soviet Union and Ukrainian independence in 1991, Kiev remained Ukraine's capital and experienced a steady influx of ethnic Ukrainian migrants from other regions of the country. During the country's transformation to a market economy and electoral democracy, Kiev has continued to be Ukraine's largest and wealthiest city. Its armament-dependent industrial output fell after the Soviet collapse, adversely affecting science and technology, but new sectors of the economy such as services and finance facilitated Kiev's growth in salaries and investment, as well as providing continuous funding for the development of housing and urban infrastructure. Kiev emerged as the most pro-Western region of Ukraine; parties advocating tighter integration with the European Union dominate during elections.
  • 5.0K
  • 10 Nov 2022
Topic Review
Cyrillic Script
The Cyrillic script (/sɪˈrɪlɪk/ sə-RIL-ik) is a writing system used for various languages across Eurasia and is used as the national script in various Slavic, Turkic, Mongolic, Uralic, Caucasian and Iranic-speaking countries in Southeastern Europe, Eastern Europe, the Caucasus, Central Asia, North Asia and East Asia. (As of 2019), around 250 million people in Eurasia use Cyrillic as the official script for their national languages, with Russia accounting for about half of them. With the accession of Bulgaria to the European Union on 1 January 2007, Cyrillic became the third official script of the European Union, following the Latin and Greek alphabets. In the 9th century AD, the Bulgarian tsar Simeon I the Great – following the cultural and political course of his father Boris I – commissioned a new script, the Early Cyrillic alphabet, to be made at the Preslav Literary School in the First Bulgarian Empire, which would replace the Glagolitic script, produced earlier by Saints Cyril and Methodius and the same disciples that created the new Slavic script in Bulgaria. The usage of the Cyrillic script in Bulgaria was made official in 893. The new script became the basis of alphabets used in various languages, especially those of Orthodox Slavic origin, and non-Slavic languages influenced by Bulgarian. For centuries Cyrillic was used by Catholic and Muslim Slavs too (see Bosnian Cyrillic). Cyrillic is derived from the Greek uncial script, augmented by letters from the older Glagolitic alphabet, including some ligatures. These additional letters were used for Old Church Slavonic sounds not found in Greek. The script is named in honor of the Saint Cyril, one of the two Byzantine brothers, Saints Cyril and Methodius, who created the Glagolitic alphabet earlier on. Modern scholars believe that Cyrillic was developed and formalized by the early disciples of Cyril and Methodius in the Preslav Literary School, the most important early literary and cultural centre of the First Bulgarian Empire and of all Slavs. The school developed the Cyrillic script: The earliest datable Cyrillic inscriptions have been found in the area of Preslav. They have been found in the medieval city itself, and at nearby Patleina Monastery, both in present-day Shumen Province, in the Ravna Monastery and in the Varna Monastery. With the orthographic reform of Saint Evtimiy of Tarnovo and other prominent representatives of the Tarnovo Literary School (14th and 15th centuries) such as Gregory Tsamblak or Constantine of Kostenets the school influenced Russian, Serbian, Wallachian and Moldavian medieval culture. That is famous in Russia as the second South-Slavic influence. In the early 18th century, the Cyrillic script used in Russia was heavily reformed by Peter the Great, who had recently returned from his Grand Embassy in Western Europe. The new letterforms, called the Civil script, became closer to those of the Latin alphabet; several archaic letters were abolished and several letters were designed by Peter himself. Letters became distinguished between upper and lower case. West European typography culture was also adopted. The pre-reform forms of letters called 'Полуустав' were notably kept for use in Church Slavonic and are sometimes used in Russian even today, especially if one wants to give a text a 'Slavic' or 'archaic' feel.
  • 4.9K
  • 22 Nov 2022
Topic Review
Science, Technology, Society and Environment Education
Science, technology, society and environment (STSE) education, originates from the science technology and society (STS) movement in science education. This is an outlook on science education that emphasizes the teaching of scientific and technological developments in their cultural, economic, social and political contexts. In this view of science education, students are encouraged to engage in issues pertaining to the impact of science on everyday life and make responsible decisions about how to address such issues (Solomon, 1993 and Aikenhead, 1994)
  • 4.9K
  • 20 Oct 2022
Topic Review
Younger Dryas
The Younger Dryas (around 12,900 to 11,700 years BP) was a return to glacial conditions after the Late Glacial Interstadial, which temporarily reversed the gradual climatic warming after the Last Glacial Maximum (LGM) started receding around 20,000 BP. It is named after an indicator genus, the alpine-tundra wildflower Dryas octopetala, as its leaves are occasionally abundant in late glacial, often minerogenic-rich sediments, such as the lake sediments of Scandinavia. Physical evidence of a sharp decline in temperature over most of the Northern Hemisphere has been discovered by geological research. This temperature change occurred at the end of what the earth sciences refer to as the Pleistocene epoch and immediately before the current, warmer Holocene epoch. In archaeology, this time frame coincides with the final stages of the Upper Paleolithic in many areas. The Younger Dryas was the most recent and longest of several interruptions to the gradual warming of the Earth's climate since the severe LGM, about 27,000 to 24,000 years BP. The change was relatively sudden, taking place in decades, and it resulted in a decline of temperatures in Greenland by 4 to 10°C (7.2 to 18°F) and advances of glaciers and drier conditions, over much of the temperate Northern Hemisphere. It is thought to have been caused by a decline in the strength of the Atlantic meridional overturning circulation, which transports warm water from the Equator towards the North Pole, in turn thought to have been caused by an influx of fresh, cold water from North America to the Atlantic. The Younger Dryas was a period of climatic change, but the effects were complex and variable. In the Southern Hemisphere and some areas of the Northern Hemisphere, such as southeastern North America, a slight warming occurred.
  • 4.8K
  • 14 Oct 2022
  • Page
  • of
  • 16
Video Production Service