ejaasaari/simplewiki-2025-04-01 huggingface dataset:
Heat conduction (or thermal conduction) is the movement of heat from one object to another one that has different temperature when they are touching each other. For example, we can warm our hands by touching hot-water bottles. When the cold hands touch the hot-water bottle, heat flows from the hotter object (hot-water bottle) to the colder one (hand). People make things with different thermal conductivity, for example cookware to heat things or insulated containers to keep hot things hot or cold things cold. Other ways to transfer heat are by thermal radiation and/or convection. Usually more than one of these processes happen at the same time. Microscopic explanation. In the atomic theory solids, liquids and gases are made of tiny particles called "atoms". The temperature of the material measures how fast the atoms are moving and the heat measures the total amount of energy due to the vibration of the atoms. Conduction can happen when one part of a material is heated. The atoms in this part vibrate faster and are more likely to hit their neighbors. The collisions cause those atoms also to move faster, passing the heat energy to them. In this way the energy travels through the solid. (Rather like the way energy passes along a set of tumbling dominos). The atomic picture also helps explain why conduction is more important in solids: in solids the atoms are close together and unable to move around. In liquids and gases the particles can move past each other, so the collisions are less common. Law of heat conduction. The law of heat conduction, also known as Fourier's law, means that the rate, in time, of heat transfer through a material is proportional to the negative gradient in the temperature and to the area at right angles, to that gradient, through which the heat is flowing:  formula_1 where: "Q" is the amount of heat transferred, and  "t" is the time taken, and  "k" is the material's thermal conductivity' and  "S" is the area through which the heat is flowing, and  "T" is the temperature. Thermal conductivity usually varies with temperature, but the variation can be small, over a significant range of temperatures, for some common materials.
Judith Weir CBE (born 11 May 1954) is a British composer. She is well known for her theatre works, choral music, orchestral music and chamber music. Early life. Weir was born in Cambridge, England to Scottish parents. While she was still at school she trained with the composer John Tavener. She played the oboe in the National Youth Orchestra of Great Britain. She then studied at the University of Cambridge where her teacher was Robin Holloway. Career. Judith Weir’s music has harmonies which are very exciting and original. Her Christmas carol "Illuminare" has become very popular, but it is quite difficult and needs a good choir to pitch the notes of the dissonant chords. She often uses medieval history as inspiration for her music, as well as music from her native Scotland, e.g. piobaireachd, which is a kind of variation form using small intervals. Her music often tells stories. Her operas include "A Night at the Chinese Opera", "The Vanishing Bridegroom", "Blond Eckbert", and "Armida", an opera for television. From 1995 to 2000, she was the artistic director of the Spitalfields Festival in London. She has composed works for the City of Birmingham Symphony Orchestra. She has received many honours, including the CBE in 1995.
A vassal during the feudalism of medieval Europe, was someone who had shared duties with a lord. Usually the vassal provided soldiers to the lord. The lord used his army of soldiers from all of his vassals to protect those vassals. The lord also gave him the piece of land that he held as a fief. By analogy the term "vassal" is used also for similar systems in other feudal societies. Western vassalage. The development of the "vassal", in a society that was increasingly organised around the concept of "lordship"– in French the "seigneur"– is one sign that Antiquity ended and the Early Middle Ages began. Lordship is the basic social institution as Tacitus described them in his book "Germania". The Roman West experienced them for the first time in the Migration Period. As the system developed in the seventh century, the vassals were gangs of freemen who subjected themselves, in some degree of formality, to the authority of a leader, from whom they could expect to be fed, clothed and armed. The quality of a vassal was only in his fighting ability and the strength of his loyalty. The etymology (where the word came from) of "vassal" is from a Celtic word "gwas" "boy" that meant a young male slave, with a Latinised form, "vassus" that appeared in Salic Law (Rouche 1987 p 429), like the way "knight" came from the from Old English word "cniht" and similar words in Frisian and Dutch, all meaning "lad" .
The migration period, or barbarian invasions or Völkerwanderung happened in AD 300–700 in Europe, at the end of ancient history and during the Early Middle Ages. The migrations included the Goths, Vandals, Franks, and other Germanic; Bulgar; and Slavic tribes. They may have been influenced by attacks of the Huns in the East and may also be connected to the Turkic migrations in Central Asia, overpopulation, or climate changes. The migration period also included groups of Angles, Saxons, Frisians, and some Jutes to Britain. Migrations would continue well into the Middle Ages, beyond 1000 AD, with successive waves of Slavs, Roma, Avars, Bulgars, Hungarians, Pechenegs, Cumans, and Tatars, which changed the ethnic makeup of Eastern Europe. Historians in Western Europe, however, tend to stress the migrations that were most relevant to that area.
San Francisco Bay is a shallow bay in northern California, along the Pacific Ocean. It is an estuary because salt water from the ocean mixes with fresh water from rivers, especially the Sacramento and San Joaquin rivers. These rivers carry water from the Sierra Nevada mountains through the Central Valley. Water from about forty percent of California enters the bay. The Sacramento and San Joaquin rivers enter the Suisun Bay. There water flows through the Carquinez Strait to meet with the Napa River at the entrance to San Pablo Bay. This connects at its south end to the San Francisco Bay. The San Francisco Bay is connected to the Pacific by a strait called the Golden Gate. However, this entire group of interconnected bays is often called "the San Francisco Bay". San Francisco Bay lies in the US state of California and is surrounded by a region known as the San Francisco Bay Area, that includes the big cities of San Francisco, Oakland, and San Jose. The Bay covers somewhere between 400 and 1,600 square miles (1,040 to 4,160 square kilometres), depending on which sub-bays (such as San Pablo Bay), estuaries, wetlands, and so on are included in the measurement.
Ahmed Yassin (Arabic: الشيخُ أَحْمَدُ إِسْمَاعِيلُ) (June 1936 – March 22, 2004) was a spiritual leader of the militant Palestinian group Hamas. Life. Ahmed Yassin was born on June 1936 in al-Jura, British Mandate of Palestine. He helped create Hamas and became its spiritual leader in 1987. To other members of Hamas he was a hero but he was blamed by the Israeli government for planning suicide bombings and other attacks against Israel. He claimed that was the only way of fighting occupation. He was confined to a wheelchair because he was paralyzed since age 12, he was also nearly blind and could barely hear. He was very powerful and influential. Yassin's birth date is in dispute. He claimed he was born 1/1/1938, however, his passport indicated 1/1/1937. To some he was a hero, to some he was a well known member of a terrorist organization. He was also a symbolic figure for Palestinians to fight against Israel. Death. Yassin was killed in an airstrike in Gaza City by the Israeli Army after he left a mosque in Gaza in the early morning hours. He was 67 years old.
In physics, the field strength of a field is the magnitude (size) of its (vector) value. This means that the force exerted by the field on a given object is proportional to the field strength. In differential geometry, the field strength is another name for the curvature form. For the electromagnetic field, the curvature form is an antisymmetric matrix whose elements are the electric field and magnetic field: the electromagnetic tensor. In radio engineering, field strength is the strength of radio waves in a particular location.
In physics, a field means that a physical quantity is assigned to every point in space (or, more generally, spacetime). A field is seen as extending throughout a large region of space so that it influences everything. The strength of a field usually varies over a region. Michael Faraday became the first to coin the term "field", in 1849. For some fields, there is a number for each point in space. They are called "scalar fields". For more complicated fields, there are more than one number for each point in space. They are called "vector fields" or "tensor fields". For example, one can model a gravitational field by a vector field where a vector indicates the acceleration a mass would experience at each point in space. Other examples are temperature fields or air pressure fields, which are often illustrated on weather reports by isotherms and isobars by joining up the points of equal temperature or pressure respectively. Types of fields. Quantum fields. It is now believed that quantum mechanics should underlie all physical phenomena. Field theory. A field theory is a physical theory that describes how one or more physical fields interact with matter.
In mathematics, the trigonometric functions are a set of functions which relate angles to the sides of a right triangle. There are many trigonometric functions, the 3 most common being sine, cosine, tangent, followed by cotangent, secant and cosecant. The last three are called reciprocal trigonometric functions, because they act as the reciprocals of other functions. Secant and cosecant are rarely used. Definition. The trigonometric functions sometimes are also called circular functions. They are functions of an angle; they are important when studying triangles, among many other applications. Trigonometric functions are commonly defined as ratios of two sides of a right triangle containing the angle, and can equivalently be defined as the lengths of various line segments from a unit circle (a circle with radius of one). Right triangle definitions. In order to define the trigonometric functions for the angle "A", start with a right triangle that contains the angle "A": We use the following names for the sides of the triangle: All triangles are taken to exist in Euclidean geometry, so that the inside angles of each triangle sum to π radians (or 180°); therefore, for a right triangle, the two non-right angles are between zero and π/2 radians. Notice that strictly speaking, the following definitions only define the trigonometric functions for angles in this range. We extend them to the full set of real arguments by using the unit circle, or by requiring certain symmetries and that they be periodic functions. 1) The sine of an angle is the ratio of the length of the opposite side to the length of the hypotenuse. In our case formula_1 Note that since all those triangles are similar, this ratio does not depend on the particular right triangle that is chosen, as long as it contains the angle "A". The set of zeroes of sine (that is, the values of formula_2 for which formula_3) is formula_4 2) The cosine of an angle is the ratio of the length of the adjacent side to the length of the hypotenuse. In our case formula_5 The set of zeroes of cosine is formula_6 3) The
An archer is a person who practices archery, using a bow to shoot arrows. Archer or Archers may also refer to:
Archery is the practice of using a bow to shoot arrows. Archery has historically been used in hunting and combat and has become a precision sport. A person practicing archery is called an "archer", and one who enjoys or is an expert at archery is sometimes called an toxophilite. History. The earliest evidence of archery dates back more than 9,000 years. The bow probably was used in hunting first and later adopted as a tool of warfare. It was one of the earliest forms of artillery.  Classical civilizations, notably the Persians, Macedonians, Nubians, Greeks, Parthians, Indians, Japanese, Chinese, and Koreans, had large numbers of archers in their armies. Archers in chariots were especially important in armies of ancient Egypt. Arrows were very destructive against massed formations, and the use of archers helped win battles.  One of the primary sub-genres of archery is mounted archery. Japanese Samurai, North American tribes, Turkish nomadic groups, Persian armies and more honed the skill of hunting and warfare through mounted archery. The army of the Mongol Empire was mostly archers on horseback. Though archery fell out of practical use, it never fully went away as a sport. As early as the 1480s in Britain, societies like the Ancient Society of Kilwinning Archers were having archery competitions.
John Felix Anthony Cena Jr. (born April 23, 1977) is an American professional wrestler, actor and former rapper. He currently works for the WWE. Cena has won the WWE Championship/WWE World Heavyweight Championship a record thirteen times, the World Heavyweight Championship three-times, the United States Championship five times and both the WWE and World Tag Team Championship twice. Also, Cena won the Royal Rumble in 2008 and 2013. As for his musical career, Cena has released an album called "You Can't See Me". Cena has also been featured in the movies "The Marine", "12 Rounds" and "Legendary". He starred as Peacemaker in the 2021 movie "The Suicide Squad" and his own television series for HBO Max. His most famous catchphrase is "You Can't See Me" which has become a very well-known meme in Western Society. Career. WWE (2001–present). Cena was signed by the person in charge of Talent Relations, Jim Ross on behalf of the WWE (then known as the World Wrestling Federation WWF). According to Ross, when he returned to Connecticut after signing Cena he walked into Vince McMahon's office and told him "I just signed your main event for WrestleMania in 5 years." Cena would eventually make his WrestleMania debut 3 years later at WrestleMania XX in 2004, winning the WWE United States Championship from The Big Show. At WrestleMania 21 the following year, he won the WWE Championship from John "Bradshaw" Layfield. At 2006's WresteMania 22 he wrestled for the first time in a WrestleMania main event, beating Triple H to keep his WWE Championship. He would go on to main event WrestleMania in 2007 vs. Shawn Michaels, in 2011 vs. The Miz, and in 2012 and 2013 vs. The Rock. He also wrestled in many other WWE premium live events. In 2010, during a match between Wade Barrett and Randy Orton, Orton won so Cena was forced to retire. He was rehired by Wade Barrett and defeated him at . He was
A signal transduction in biology is a cellular mechanism. It converts a stimulus into a response in the cell. There are two stages in this process: So, signal transduction starts with a signal to a cell receptor, and ends with a change in cell function. In either step, the signal can be amplified. Thus, one signalling molecule can cause many responses. Receptors are in the cell membrane, with part of the receptor outside and part inside the cell.  The chemical signal binds to the outer portion of the receptor, changing its shape. This causes another signal inside the cell.  Some chemical messengers, such as testosterone, can pass through the cell membrane, and bind directly to receptors in the cytoplasm or nucleus. Sometimes there is a cascade of signals within the cell. With each step of the cascade, the signal can be amplified, so a small signal can result in a large response. Eventually, the signal creates a change in the cell, either in the expression of the DNA in the nucleus or in the activity of enzymes in the cytoplasm. Most often, ordered sequences of biochemical reactions inside the cell are involved. These are carried out by enzymes and linked through second messengers. So a "second messenger pathway" is produced. These things usually happen quickly, sometimes very quickly. They may last from milliseconds (in the case of ion flux) to days for gene expression. The number of proteins and other molecules that take part increases during the process. So a 'signal cascade' develops and "a relatively small stimulus may cause a large response". In bacteria and other single-cell organisms, the transduction processes a cell has limits the number of ways it can respond to its environment. In multicellular organisms, lots of different signal transduction processes are used to coordinate the behavior of individual cells. By this means the function of the organism as a whole is organized. The more complex the organism, the more complex the repertoire of signal transduction processes the organism must possess. Thus, sensing of both the external and internal environment at the cellular level, relies on signal transduction. Many disease processes such as diabetes, heart disease, autoimmunity and cancer arise from defects in signal transduction pathways. This highlights the critical importance of signal transduction to biology and medicine. These systems of communication between cells are extremely ancient, and are found in all metazoa.
Flux is a term in physics and mathematics. It is broadly defined as "How much stuff goes through a thing" (or into an area). The word "flux" is similar to "flow". For instance, in a butterfly net the amount of air passing through the net is the flux. Movement of substances. In the study of transport phenomena (heat transfer, mass transfer and fluid dynamics), flux is defined as flow per unit area, where flow is the movement of some quantity per time. Flux, in this definition, is a vector. There are many fluxes used in the study of transport phenomena. Each type of flux has its own distinct unit of measurement along with distinct physical constants. Six of the most common forms of flux from the transport literature are defined as: Electromagnetism. In the field of electromagnetism, flux is usually the integral of a vector quantity over a finite surface. The result of this integration is a scalar quantity. The magnetic flux is the integral of the magnetic vector field over a surface, and the electric flux is defined similarly. Using this definition, the flux of the Poynting vector over a specified surface is the rate at which electromagnetic energy flows through that surface. Confusingly, the Poynting vector is sometimes called the "power flux", which is an example of the first usage of flux, above. It has units of watts per square metre (W/m2).
Neuroscience (or neurobiology) is the scientific study of the nervous system. It is the branch of biology which investigates every aspect of the brain and nervous system. The nervous system is made of billions of neurons connected together and to other systems in the body. The central nervous system includes the brain, spinal cord and retina. It is connected to the rest of the body via the peripheral nervous system.  Research themes. Neuroscience research focusses on a set of themes and questions.
Conversation analysis (commonly abbreviated as CA) is the study of talk in social interaction. CA tries to describe the structure and patterns of interaction, whether this is institutional (in the school, doctor's surgery, courts or elsewhere) or casual conversation.  The term “conversation” to label this disciplinary movement is misleading if read in a colloquial sense, as many have.
Mark-Anthony Turnage (born Grays, Essex, 10 June 1960) is an English composer. He is one of the most original composers in his country today.  Turnage studied at the Royal College of Music and won all the major prizes. He became famous when he wrote an opera called "Greek". It is typical of his musical style: quite lyrical but also very dramatic and aggressive. His music is often inspired by jazz. Other works include "Kai", "Rockaby", "Blood on the Floor", "Dispelling the Fears", "Drowned Out" and "Three Screaming Popes". He has written music for the English National Opera, City of Birmingham Symphony Orchestra and the Chicago Symphony Orchestra.
A hydrothermal vent is an opening in the seabed of the Earth by which geothermal energy escapes. Sea water enters, becomes very hot, and rises. The hottest ones carry many black chemicals and are called black smokers. Scientists have found fewer white smokers. Heat escapes from underground in many places. If they are on land, they are usually hot springs, geysers, or fumaroles. Many archaea and bacteria live near hydrothermal vents. They support giant tube worms, clams and shrimp, and many other eukaryotes. The earliest known life forms are thought to have lived near such vents. Biological communities. Deep sea organisms have no access to sunlight, so they must depend on nutrients in the chemical deposits and hydrothermal fluids in which they live. Despite this, hydrothermal vent zones have more than 10,000 to 100,000 times as much life as the rest of the seafloor. Hydrothermal vent communities are able to sustain such vast amounts of life because vent organisms depend on chemosynthetic bacteria for food, as opposed to the photosynthetic plants other ecosystems use. These bacteria use sulfur compounds, particularly hydrogen sulfide, a chemical highly toxic to most other organisms, to produce organic material through the process of chemosynthesis. The chemosynthetic bacteria grow into a thick mat which attracts other organisms such as amphipods and copepods which graze upon the bacteria directly. Larger organisms such as snails, shrimp, crabs, giant tube worms, fish, and octopus form a food chain of predator and prey relationships above the primary consumers.  The main groups of organisms around seafloor vents are worms, gastropods, and crustaceans, with large bivalves, and 'eyeless' shrimp making up the bulk of non-microbial organisms. Tube worms form an important part of the community around a hydrothermal vent. They absorb nutrients directly into their tissues. There are approximately 285 billion bacteria per ounce of tubeworm tissue. Tubeworms have red plumes which contain haemoglobin. Haemoglobin combines hydrogen sulfide and transfers it to the bacteria living inside the worm. In return the bacteria nourish the worm
Guavas are plants in the genus "Psidium" of the family Myrtaceae. There are about 100 species of tropical shrubs and small trees in the genus. They are native to Mexico, the Caribbean, Central America and the northern part of South America. Now they are found in all the tropical, and in some subtropical, regions because they are edible fruits. Guava are also a kind of berry fruit on those plants. There are many kinds of guavas. The most common guava is the apple guava ("Psidium guajava"): it is so common that the word 'guava' usually refers to this species. Red guavas are called marooonguava. In 100 g of guava are 200 mg of vitamin C, which means that guavas have five times more vitamin C than oranges.