SUMMARY / RELATED TOPICS

Alevism

Alevism is a syncretic and local Islamic tradition, whose adherents follow the mystical teachings of Ali, the Twelve Imams and a descendant—the 13th century Alevi saint Haji Bektash Veli. Alevis are found in Turkey among ethnic Turks and Kurds, make up somewhere between 10 and 20% of Turkey's population, they are the second-largest sect of Islam in Turkey, with Sunni Islam being the largest. After the death of the Islamic prophet Muhammad, a dispute arose about his legitimate successor; the Islamic community was divided into those who adhered to Abu Bakr, named Sunnis, those who sided with Ali, called Shia. Concurrently, people who sided with Ali were called Alevis, defined as "those who adore Ali and his family". Therefore, some authors use Shiism synonymously with Alevism. However, Alevism is not Shiism though it is influenced by it and although they share some common beliefs with the Twelver Shia, their rites and practises are different from Shiism, thus Alevism incorporates Turkish folk beliefs present during the 14th century, such as Folk Belief's, mixed with Shia and Sufi beliefs that were adopted by some Turkish tribes and integrated into Sunni Islam.

Alevis have some links with Twelver Shia Islam, but do not follow taqlid towards a Marja' "source of emulation". Some practices of the Alevis are based on Sufi elements of the Bektashi tariqa. "Alevi" is explained as referring to Ali, the cousin and son-in-law of Muhammad. The name represents a Turkish form of the word ‘Alawi "of or pertaining to Ali". A minority viewpoint is that of the Ishikists, who assert, "Alevi" was derived from "Alev" in reference to fire, extensively used in Alevi rituals. According to them the use of candles is based on Quran chapter 24, verses 35 and 36: "God is the Light of the heavens and the earth; the example of His light is like a niche within which there is a lamp, the lamp is encased in a glass, the glass is like a radiant planet, lit from a blessed olive tree, neither of the east nor of the west, its oil nearly gives off light if not touched by fire. Light upon light, God guides to His light whom He pleases, and God sets forth examples for the people, God is aware of all things.

In houses, which God has permitted to be raised to honor. According to scholar Soner Çağaptay, Alevism is a "relatively unstructured interpretation of Islam". Journalist Patrick Kingsley states that for some self-described Alevi, their religion is "simply a cultural identity, rather than a form of worship". Many teachings are based on an orally transmitted tradition, traditionally kept secret from outsiders. Alevis profess the Islamic shahada, but adding "Ali is the friend of God"; the basis for Alevis' most distinctive beliefs is found in the Buyruks. Included are hymns by figures such as Shah Ismail or Pir Sultan Abdal, stories of Hajji Bektash and other lore. In Alevi cosmology, God is called Al-Haqq or referred to as Allah. God created life, so the created world can reflect His Being. Alevis believe in the unity of Allah and Ali, but this is not a trinity composed of God and the historical figures of Muhammad and Ali. Rather and Ali are representations of Allah's light, being neither independent from God, nor separate characteristics of Him.

In Alevi writings are many references to the unity of Muhammad and Ali, such as: Ali Muhammed'dir uh dur fah'ad, Muhammad Ali, Gördüm bir elmadır, el-Hamdû'liLlâh. The phrase "For the love of Allah-Muhammad-Ali" is common to several Alevi prayers. Despite the different description of God, there can't be found a trace of God ruling based on fear. Accordingly, God will not judge the people by their acts of worship and there is no literal hell or heaven with material punishments or pleasures; however Alevism believes in the immortality of the soul. Alevis, who believe in a literal existence of supernatural beings believe in good and bad angels the same as Orthodox Islam, in spirits; however Alevis, who do not believe in the supernatural regard Satan as a metaphor for human's evil desires. Alevis, who believe in a literal existence of spiritual creatures adhere to superstitional beliefs such as jinn or the evil eye. Like Orthodox Islam, all Alevis acknowledge at least the four scriptures revealed from heaven.

Additionally, Alevis don't mind to look to other religious books outside the four major ones as sources for their beliefs including Hadiths, Nahjul Balagha and Buyruks. Alevism acknowledges the Islamic prophets; the Twelve Imams are part of another common Alevi belief. Each Imam represents a different aspect of the world, they are realized as twelve services or On İki Hizmet which are performed by members of the Alevi community. Each Imam is believed to be a reflection of Ali ibn Abu Talib, the first Imam of the Shi'ites, there are references to the "First Ali", Imam Hasan the "Second'Ali", so on up to the "Twelfth'Ali", Imam Mehdi; the Twelfth Imam represents the Messianic Age. There are two sides to

1825 Klare

1825 Klare, provisional designation 1954 QH, is an asteroid from the central region of the asteroid belt 15 kilometers in diameter. It was discovered on 31 August 1954, by German astronomer Karl Reinmuth at Heidelberg Observatory in southern Germany; the asteroid was named after Heidelberg astronomer Gerhard Klare. The stony asteroid orbits the Sun in the central main-belt at a distance of 2.4–3.0 AU once every 4 years and 5 months. Its orbit has an inclination of 4 ° with respect to the ecliptic. First identified as 1934 CH at Uccle Observatory in 1934, Klare's observation arc begins 20 years prior to its official discovery observation. Klare has been the subject of multiple photometric lightcurve studies, which gave a well-determined rotation period between 4.741 and 4.744 hours with a brightness variation between 0.70 and 0.90 magnitude. Measurements have been used as the basis for generating a three-dimensional model of its shape; the Collaborative Asteroid Lightcurve Link adopts a period 4.744 hours with an amplitude of 0.70 magnitude.

According to the survey carried out by the Japanese Akari satellite, Klare measures 14.69 kilometers in diameter, its surface has an albedo of 0.167, while CALL assumes an albedo of 0.10 – a compromise value for asteroids with a semi-major axis between 2.6 and 2.7 AU, for which neither a S nor a C type has been determined – and calculates a diameter of 19.21 kilometers with an absolute magnitude of 11.7. Klare was named after Gerhard Klare, an observing astronomer at Heidelberg Observatory since 1960, whose fields of interest include minor planets, he is known for his numerous contributions in the yearbook series "Reviews in Modern Astronomy" of the Astronomische Gesellschaft. The official naming citation was published by the Minor Planet Center on 18 April 1977. PowerPoint presentation – Asteroid 1825 Klare, by Mahfuz Krueng Asteroid Lightcurve Database, query form Dictionary of Minor Planet Names, Google books Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend Discovery Circumstances: Numbered Minor Planets - – Minor Planet Center 1825 Klare at AstDyS-2, Asteroids—Dynamic Site Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info 1825 Klare at the JPL Small-Body Database Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters

Prompt criticality

In nuclear engineering, prompt criticality describes a nuclear fission event in which criticality is achieved with prompt neutrons alone and does not rely on delayed neutrons. As a result, prompt criticality causes a much more rapid growth in the rate of energy release than other forms of criticality. Nuclear weapons are based on prompt criticality, while most nuclear reactors rely on delayed neutrons to achieve criticality. An assembly is critical if each fission event causes, on average one additional such event in a continual chain; such a chain is a self-sustaining fission chain reaction. When a uranium-235 atom undergoes nuclear fission, it releases between one and seven neutrons. In this situation, an assembly is critical if every released neutron has a 1/2.4 = 0.42 = 42% probability of causing another fission event as opposed to either being absorbed by a non-fission capture event or escaping from the fissile core. The average number of neutrons that cause new fission events is called the effective neutron multiplication factor denoted by the symbols k-effective, k-eff or k.

When k-effective is equal to 1, the assembly is called critical, if k-effective is less than 1 the assembly is said to be subcritical, if k-effective is greater than 1 the assembly is called supercritical. In a supercritical assembly the number of fissions per unit time, N, along with the power production, increases exponentially with time. How fast it grows depends on the average time it takes, T, for the neutrons released in a fission event to cause another fission; the growth rate of the reaction is given by: N = N 0 k t / T Most of the neutrons released by a fission event are the ones released in the fission itself. These are called prompt neutrons, strike other nuclei and cause additional fissions within nanoseconds. A small additional source of neutrons is the fission products; some of the nuclei resulting from the fission are radioactive isotopes with short half-lives, nuclear reactions among them release additional neutrons after a long delay of up to several minutes after the initial fission event.

These neutrons, which on average account for less than one percent of the total neutrons released by fission, are called delayed neutrons. The slow timescale on which delayed neutrons appear is an important aspect for the design of nuclear reactors, as it allows the reactor power level to be controlled via the gradual, mechanical movement of control rods. Control rods contain neutron poisons as a means of altering k-effective. With the exception of experimental pulsed reactors, nuclear reactors are designed to operate in a delayed-critical mode and are provided with safety systems to prevent them from achieving prompt criticality. In a delayed-critical assembly, the delayed neutrons are needed to make k-effective greater than one, thus the time between successive generations of the reaction, T, is dominated by the time it takes for the delayed neutrons to be released, on the order of seconds or minutes. Therefore, the reaction will increase with a long time constant; this is slow enough to allow the reaction to be controlled with electromechanical control systems such as control rods, as such all nuclear reactors are designed to operate in the delayed-criticality regime.

In contrast, a critical assembly is said to be prompt-critical if it is critical without any contribution from delayed neutrons and prompt-supercritical if it is supercritical without any contribution from delayed neutrons. In this case the time between successive generations of the reaction, T, is only limited by the fission rate from the prompt neutrons, the increase in the reaction will be rapid, causing a rapid release of energy within a few milliseconds. Prompt-critical assemblies are created by design in nuclear weapons and some specially designed research experiments; when differentiating between a prompt neutron versus a delayed neutron, the difference between the two has to do with the source from which the neutron has been released into the reactor. The neutrons, once released, have no difference except the energy or speed which have been imparted to them. A nuclear weapon relies on prompt-supercriticality, whereas nuclear power reactors use delayed-criticality to produce controllable power levels for months or years.

In order to start up a controllable fission reaction, the assembly must be delayed-critical. In other words, k must be greater than 1 without crossing the prompt-critical threshold. In nuclear reactors this is possible due to delayed neutrons; because it takes some time before these neutrons are emitted following a fission event, it is possible to control the nuclear reaction using control rods. A steady-state reactor is operated so that it is critical due to the delayed neutrons, but would not be so without their contribution. During a gradual and deliberate increase in reactor power level, the reactor is delayed-supercritical; the exponential increase of reactor activity is slow enough to make it possible to control the criticality factor, k, by inserting or withdrawing rods of neut