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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.
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  • 25 Oct 2022
Topic Review
Soufrière Hills Volcano
User:RMCD bot/subject notice The Soufrière Hills volcano is an active, complex stratovolcano with many lava domes forming its summit on the Caribbean island of Montserrat. Many volcanoes in the Caribbean are named Soufrière (French: "sulfur outlet"). These include La Soufrière or Soufrière Saint Vincent on the island of Saint Vincent, and La Grande Soufrière on Guadeloupe. After a long period of dormancy, the Soufrière Hills volcano became active in 1995 and has continued to erupt ever since. Its eruptions have rendered more than half of Montserrat uninhabitable, destroying the capital city, Plymouth, and causing widespread evacuations: about two thirds of the population have left the island. It is andesitic in nature, and the current pattern of activity includes periods of lava dome growth, punctuated by brief episodes of dome collapse which result in pyroclastic flows, ash venting, and explosive eruption. The volcano is monitored by the Montserrat Volcano Observatory. Volcanic gas emissions from this volcano are measured by a Multi-Component Gas Analyzer System, which detects pre-eruptive degassing of rising magmas, improving prediction of volcanic activity.
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  • 25 Oct 2022
Topic Review
Foreshadow (Security Vulnerability)
Foreshadow (known as L1 Terminal Fault (L1TF) by Intel) is a vulnerability that affects modern microprocessors that was first discovered by two independent teams of researchers in January 2018, but was first disclosed to the public on 14 August 2018. The vulnerability is a speculative execution attack on Intel processors that may result in the disclosure of sensitive information stored in personal computers and third-party clouds. There are two versions: the first version (original/Foreshadow) (CVE-2018-3615) targets data from SGX enclaves; and the second version (next-generation/Foreshadow-NG) (CVE-2018-3620 and CVE-2018-3646) targets virtual machines (VMs), hypervisors (VMM), operating systems (OS) kernel memory, and System Management Mode (SMM) memory. A listing of affected Intel hardware has been posted. Foreshadow is similar to the Spectre security vulnerabilities discovered earlier to affect Intel and AMD chips, and the Meltdown vulnerability that also affected Intel. However, AMD products, according to AMD, are not affected by the Foreshadow security flaws. According to one expert, " lets malicious software break into secure areas that even the Spectre and Meltdown flaws couldn't crack". Nonetheless, one of the variants of Foreshadow goes beyond Intel chips with SGX technology, and affects "all [Intel] Core processors built over the last seven years". Foreshadow may be very difficult to exploit, and there seems to be no evidence to date (15 August 2018) of any serious hacking involving the Foreshadow vulnerabilities. Nevertheless, applying software patches may help alleviate some concern, although the balance between security and performance may be a worthy consideration. Companies performing cloud computing may see a significant decrease in their overall computing power; individuals, however, may not likely see any performance impact, according to researchers. The real fix, according to Intel, is by replacing today's processors. Intel further states, "These changes begin with our next-generation Intel Xeon Scalable processors (code-named Cascade Lake), as well as new client processors expected to launch later this year ." On 16 August 2018, researchers presented technical details of the Foreshadow security vulnerabilities in a seminar, and publication, entitled "Foreshadow: Extracting the Keys to the Intel SGX Kingdom with Transient Out-of-Order Execution" at a USENIX security conference.
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  • 25 Oct 2022
Topic Review
Forensic Identification
Forensic identification is the application of forensic science, or "forensics", and technology to identify specific objects from the trace evidence they leave, often at a crime scene or the scene of an accident. Forensic means "for the courts".
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  • 25 Oct 2022
Topic Review
MRCI (Microsoft)
DriveSpace (initially known as DoubleSpace) is a disk compression utility supplied with MS-DOS starting from version 6.0 in 1993 and ending in 2000 with the release of Windows Me. The purpose of DriveSpace is to increase the amount of data the user could store on disks by transparently compressing and decompressing data on-the-fly. It is primarily intended for use with hard drives, but use for floppy disks is also supported. This feature was removed in Windows XP and later.
  • 481
  • 25 Oct 2022
Topic Review
Work
In physics, work is the energy transferred to or from an object via the application of force along a displacement. In its simplest form, it is often represented as the product of force and displacement. A force is said to do positive work if (when applied) it has a component in the direction of the displacement of the point of application. A force does negative work if it has a component opposite to the direction of the displacement at the point of application of the force. For example, when a ball is held above the ground and then dropped, the work done by the gravitational force on the ball as it falls is equal to the weight of the ball (a force) multiplied by the distance to the ground (a displacement). When the force F is constant and the angle between the force and the displacement s is θ, then the work done is given by: [math]\displaystyle{ W = F s \cos{\theta} }[/math] Work is a scalar quantity, so it has only magnitude and no direction. Work transfers energy from one place to another, or one form to another. The SI unit of work is the joule (J), the same unit as for energy.
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  • 25 Oct 2022
Topic Review
Electricity Meter
thumb|North American domestic analogue electricity meter. thumb|Electricity meter with transparent plastic case (Israel) thumb|North American domestic electronic electricity meter An electricity meter, electric meter, electrical meter, or energy meter is a device that measures the amount of electric energy consumed by a residence, a business, or an electrically powered device. Electric utilities use electric meters installed at customers' premises for billing and monitoring purposes. They are typically calibrated in billing units, the most common one being the kilowatt hour (kWh). They are usually read once each billing period. When energy savings during certain periods are desired, some meters may measure demand, the maximum use of power in some interval. "Time of day" metering allows electric rates to be changed during a day, to record usage during peak high-cost periods and off-peak, lower-cost, periods. Also, in some areas meters have relays for demand response load shedding during peak load periods.
  • 1.9K
  • 27 Oct 2022
Topic Review
Culture Inside
CultureInside is a non-profit free social networking site for the artistic community. Founded by Gila and Dominique Paris in 2008, it has offices in Luxembourg and New York City (United States). They frequently use the network to organize online exhibitions, as well as international exhibits in the United States and European Union. In April 2009 they received the label Creativity and Innovation in the European Year 2009.
  • 1.0K
  • 25 Oct 2022
Topic Review
Silicate Minerals
Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of the Earth's crust. In mineralogy, silica (silicon dioxide) SiO2 is usually considered a silicate mineral. Silica is found in nature as the mineral quartz, and its polymorphs. On Earth, a wide variety of silicate minerals occur in an even wider range of combinations as a result of the processes that have been forming and re-working the crust for billions of years. These processes include partial melting, crystallization, fractionation, metamorphism, weathering, and diagenesis. Living organisms also contribute to this geologic cycle. For example, a type of plankton known as diatoms construct their exoskeletons ("frustules") from silica extracted from seawater. The frustules of dead diatoms are a major constituent of deep ocean sediment, and of diatomaceous earth.
  • 3.6K
  • 25 Oct 2022
Topic Review
Trachodon Mummy
The Trachodon mummy is a fossilized natural mummy of Edmontosaurus annectens (originally known as Trachodon annectens), a duckbilled dinosaur. One of the finest dinosaur specimens so far discovered, it was the first including a skeleton encased in skin impressions from large parts of the body. This specimen has considerably influenced the scientific conception of duckbilled dinosaurs. Skin impressions found in between the fingers have been interpreted as evidence for an aquatic lifestyle; this hypothesis is now rejected. The mummy was found by fossil hunter Charles Hazelius Sternberg and his three sons near Lusk, Wyoming, United States in 1908. Although Sternberg was working under contract to the British Museum of Natural History, Henry Fairfield Osborn of the American Museum of Natural History managed to secure the mummy.
  • 2.0K
  • 27 Oct 2022
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