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Plutonium-239

Plutonium-239 is an isotope of plutonium. Plutonium-239 is the primary fissile isotope used for the production of nuclear weapons, although uranium-235 has been used. Plutonium-239 is one of the three main isotopes demonstrated usable as fuel in thermal spectrum nuclear reactors, along with uranium-235 and uranium-233. Plutonium-239 has a half-life of 24,110 years; the nuclear properties of plutonium-239, as well as the ability to produce large amounts of nearly pure 239Pu more cheaply than enriched weapons-grade uranium-235, led to its use in nuclear weapons and nuclear power plants. The fissioning of an atom of uranium-235 in the reactor of a nuclear power plant produces two to three neutrons, these neutrons can be absorbed by uranium-238 to produce plutonium-239 and other isotopes. Plutonium-239 can absorb neutrons and fission along with the uranium-235 in a reactor. Of all the common nuclear fuels, 239Pu has the smallest critical mass. A spherical untamped critical mass is 10.2 cm in diameter.

Using appropriate triggers, neutron reflectors, implosion geometry and tampers, this critical mass can be reduced by more than twofold. This optimization requires a large nuclear development organization supported by a sovereign nation; the fission of one atom of 239Pu generates 207.1 MeV = 3.318 × 10−11 J, i.e. 19.98 TJ/mol = 83.61 TJ/kg, or about 23,222,915 kilowatt hours/kg. Plutonium is made from uranium-238. 239Pu is created in nuclear reactors by transmutation of individual atoms of one of the isotopes of uranium present in the fuel rods. When an atom of 238U is exposed to neutron radiation, its nucleus will capture a neutron, changing it to 239U; this happens more with lower kinetic energy. The 239U rapidly undergoes two β− decays — an emission of an electron and an anti-neutrino, leaving a proton — the first β− decay transforming the 239U into neptunium-239, the second β− decay transforming the 239Np into 239Pu: U 92 238 + n 0 1 ⟶ U 92 239 → 23.5 min β − Np 93 239 → 2.356 d β − Pu 94 239 Fission activity is rare, so after significant exposure, the 239Pu is still mixed with a great deal of 238U, other components of the original material, fission products.

Only if the fuel has been exposed for a few days in the reactor, can the 239Pu be chemically separated from the rest of the material to yield high-purity 239Pu metal. 239Pu has a higher probability for fission than 235U and a larger number of neutrons produced per fission event, so it has a smaller critical mass. Pure 239Pu has a reasonably low rate of neutron emission due to spontaneous fission, making it feasible to assemble a mass, supercritical before a detonation chain reaction begins. In practice, reactor-bred plutonium will invariably contain a certain amount of 240Pu due to the tendency of 239Pu to absorb an additional neutron during production. 240Pu has a high rate of spontaneous fission events, making it an undesirable contaminant. As a result, plutonium containing a significant fraction of 240Pu is not well-suited to use in nuclear weapons, it is because of this limitation that plutonium-based weapons must be implosion-type, rather than gun-type. Moreover, 239Pu and 240Pu cannot be chemically distinguished, so expensive and difficult isotope separation would be necessary to separate them.

Weapons-grade plutonium is defined as containing no more than 7% 240Pu. Plutonium is classified according to the percentage of the contaminant plutonium-240 that it contains: Supergrade 2–3% Weapons grade 3–7% Fuel grade 7–18% Reactor grade 18% or moreA nuclear reactor, used to produce plutonium for weapons therefore has a means for exposing 238U to neutron radiation and for replacing the irradiated 238U with new 238U. A reactor running on unenriched or moderately enriched uranium contains a great deal of 238U. However, most commercial nuclear power reactor designs require the entire reactor to shut down for weeks, in order to change the fuel elements, they therefore produce plutonium in a mix of isotopes, not well-suited to weapon construction. Such a reactor could have machinery added that would permit 238U slugs to be placed near the core and changed or it could be shut down so proliferation is a concern. A few commercial power reactor designs, such as the reaktor bolshoy moshchnosti kanalniy and pressurized heavy water reactor, do permit refueling without shutdowns, they may pose

Pakistani women's cricket team in Ireland in 2000

The Pakistani women's cricket team toured Ireland in between 23 July and 2 August 2000 to play against the Irish women's national cricket team in a 5 match WODI series and in a one-off Test match, the first test appearance for Ireland women's cricket team and marked the first test match to have held in Ireland. The ODI series between the two teams were scheduled to be held as a 3 match series but both Pakistan and Ireland agreed to play in further two WODI matches after the solitary test finished only within a space of 2 days. Ireland won the only test match. Irish women's cricket team managed to win the WODI series after winning the first three ODI matches just prior to the start of the only test match, with Ireland winning the 4th One Day International on the next day after the conclusion of the test match which ended on 31 July 2000 and the fifth being abandoned due to rain; the Irish team won the historical test match on its debut against Pakistan by an innings and 54 runs, held in Dublin.

This was the only international test cricket match hosted by Ireland until 2018. 18 years after the first test appearance for the Ireland women's cricket team, their male counterparts, the Ireland men's national cricket team made its test debut against Pakistan in 2018. Isobel Joyce who made her Women's test debut in 2000 against Pakistan for Irish women's team along with Ed Joyce who made his test debut in 2018 for Irish men's team became only the second brother-sister siblings to have played in test cricket following Denise Emerson and Terry Alderman of Australia. Ed Joyce and Isobel Joyce are the only brother-sister siblings combination to have made their Test debuts when playing for their respective gender teams on the country's first test appearances

Fort Saganne

Fort Saganne is a 1984 French war film directed by Alain Corneau and starring Gérard Depardieu, Philippe Noiret, Catherine Deneuve, Sophie Marceau. Based on the 1980 novel of the same name by Louis Gardel, the film is about a soldier of humble beginnings who volunteers for service in the Sahara in 1911. After falling in love with the beautiful young daughter of the regional administrator, he is ordered to go on missions in the desert, where he engages in several successful campaigns and experiences severe loneliness. While on a diplomatic mission to Paris, he has a brief affair with a journalist. Returning to Africa, he leads a gallant defense against a feared sultan and is awarded the Grand Cross of the Legion of Honour, he returns to his home a national hero and marries the young girl he's not forgotten, but their happiness is interrupted by the onset of World War I. Fort Saganne was screened out of competition at the 1984 Cannes Film Festival. At the time of its production, Fort Saganne was France's biggest-budget film.

The film earned 2,157,767 admissions in France. In 1985, the film was nominated for four César Awards, for Best Actor, Best Cinematography, Best Costume Design, Best Sound. In 1911, a willful and determined man from peasant stock named Charles Saganne enlists in the military and is assigned to the Sahara Desert under the aristocratic Colonel Dubreuilh. Saganne attracts the attentions of the daughter of the regional administrator. In the Sahara, Saganne earns the respect including Amajan, an independent warrior. After several campaigns, Saganne travels to Paris on a diplomatic mission. After having an affair with a journalist in Paris, Saganne returns to Africa, where he leads a valliant defense against Sultan Omar, he is awarded the Grand Cross of the Legion of Honour, marries Madeleine. The onset of World War I puts his happiness at risk. Gérard Depardieu as Charles Saganne Philippe Noiret as Dubreuilh Catherine Deneuve as Louise Sophie Marceau as Madeleine of Saint-Ilette Michel Duchaussoy as Baculard Roger Dumas as Vulpi Jean-Louis Richard as Flammarin Jean-Laurent Cochet as Bertozza Pierre Tornade as Charles' Father Saïd Amadis as Amajar René Clermont as Monsieur de Saint-Ilette Hippolyte Girardot as Courette Sophie Grimaldi as Lady of Saint-Ilette Florent Pagny as Lucien For Saganne was filmed on location at Abbaye du Moncel, Oise and Mauritania where the eponymous fort was built near the Amojjar Pass close to Atar.

At the time of its production, Fort Saganne was France's biggest-budget film. The film earned 2,157,767 admissions in France. At the time of its theatrical release, the film received mixed reviews. In Variety magazine, the reviewer observed that the film "is fine in its large-scale reconstruction of a time and place and a mentality, but falters in its attempts to inscribe well-detailed characters in its wide-screen canvas." The reviewer found the romantic relationships depicted in the film to be underdeveloped. Film is weakest in describing Depardieu's romantic relationships, his brief but intense affair with special guest star Catherine Deneuve, as a journalist who maneuvers him into bed provocatively, lacks fire and poignancy. And young Sophie Marceau gets insufficient screen time to make any impression as the young bourgeois girl who pines for Depardieu and becomes his wife widow. In her review in Allmovie, Eleanor Mannikka gave the film three out of fivstars, noting that the "sweep of this epic skims over the qualities that transformed Saganne from an ordinary officer to a great military leader."

Mannikka concluded: Even though the costuming, landscape and charisma of Depardieu as Saganne and Noiret as Colonel Dubreuilh are outstanding, several subsidiary characters deliver compelling vignettes, the protagonists as an ensemble have not been scripted with much depth of character—making the three-hour epic seem a bit too long in the end. 1985 César Award Nomination for Best Actor 1985 César Award Nomination for Best Cinematography 1985 César Award Nomination for Best Costume Design 1985 César Award Nomination for Best Sound. Fort Saganne on IMDb Fort Saganne at Rotten Tomatoes Fort Saganne at AllMovie

Sirona Dental Systems

Sirona Dental Systems Inc. was a global dental equipment manufacturer, the world's largest dental equipment provider, which used to be part of Siemens. It became an independent company in 1997; the company is headquartered in New York. So far, it serves over 100 countries and districts. In 2011, the company was ranked at 27th in the list of America's Best Small Companies by Forbes; the company built the world's first dental X-ray unit, REKORD. In 2013, the company was awarded the Top Employer Award for Germany and Engineer in 2013, its subsidiary in China, Sirona China, was given Top Employer China 2014. In 2014, it won the Good Design Award 2013 for its excellence design of two products; the company was originated from Erwin Moritz Reiniger, a mechanical engineer at the University of Erlangen. In 1880s, with his technologies, he invited two business partners to set up a company producing electric-powered dental drill; the company built the world’s first dental X-ray unit in 1905 and was acquired by Siemens & Halske in 1925.

After that, the company has been engaged in developing and manufacturing a variety of dental equipment. In 1997, Sirona became an independent company when Siemens sold its dental subsidy to Schroder Ventures, acquired several industrial companies to enlarge its business in subsequent years. In 2003, the Swedish private equity firm EQT Partners acquired Sirona, only to sell this company to Madison Dearborn Partners two years later. Under their ownership, Sirona merged with Schick Technologies Inc. an American producer of X-ray devices, through a reverse takeover, resulting in a NASDAQ listing for Sirona in 2006. On 15 September 2015, Dentsply agreed to acquire Sirona Dental Systems Inc. for $5.5 billion in stock, renaming itself to Dentsply Sirona in the process. Sirona operates its business through four segments including Dental CAD/CAM Systems, Imaging Systems, Treatment Centers and Instruments. Dental CAD/CAM is engaged in providing material and equipment for dental restoration. Imaging Systems offers 3D imaging systems for dental diagnostics.

Treatment Centers produces dental basic infrastructure for medical centers. Additionally, Instruments segment manufactures a variety of dental treatment instrument, its customer base consists of dental practices and laboratories and the company distributes its products through over 450 facilities in the world

Orenburg Nature Reserve

Orenburg Nature Reserve is a Russian'zapovednik' dedicated to the preservation and restoration of four separate types of steppe landscape: Transvolga, Ural Mountains, Southern Urals and Trans-Urals. The reserve does this by spreading out across four sections across 400 km of steppes in Orenburg Oblast below the southern terminus of the Ural Mountains; the city of Orenburg sits in the middle of the four sectors 1,200 km southeast of Moscow. The reserve protects historical and archaeological sites of the Sarmation people from the seventh to third century BCE; the reserve was formally established in 1988, covers a total area of 21,653 ha. The Orenburg Reserve is divided into four sectors that exhibit different ecological communities of the region: Talovskaya Steppe; the western-most sector, with no permanent streams or rivers. Terrain is undulating plain with gullies and ravines. Sarmation burial mound. There are dark-brown soil. Burtinskaya Steppe. Sector closer to the city of Orenburg, with more developed water sources and the upper reaches of several streams.

Steppe landscape of fescue-feather grass and forb-fescue-feather grass communities. Karst lakes with waterfowl. Populations of marsh turtles. Complex of 13 Sarmation burial mounds, the largest of, 40 meters in diameter and 2.5 meters in height. Low-humus heavy loam soil. Aytuarskaya Steppe. Sector with South-Ural-Mountain-Steppe landscape of fescue-feather grass and forb-fescue-feather grass communities, with many springs. Mountainous area with tracts of aspen and black alder of unusually large size; the Aytuarka River flows along the western border. 16 Sarmation burial mounds. Karst topography with rocky outcrops and dark soil. Aschisayskaya steppe. Eastern-most sector. Site of Lake Zhurmankol, with waterfowl that includes the Mute swan. Burial mound of a nomadic tribe from the Middle Ages; the reserve is in a border zone between the semi-arid lands of Kazakhstan to the south, the forest-steppe to the north. Orenburg is located in the Pontic–Caspian steppe ecoregion; the Pontic steppe, is a grassland that stretches from eastern Romania to Kazakhstan, across the northern edges of the Black Sea and Caspian Sea.

It is an expansive prairie, flat and with fertile soil. The climate of Orenburg is Humid warm summer; this climate is characterized by large swings in temperature, both diurnally and seasonally, with warm summers and cold winters. The area has hot dry winds in the summer from central Asia; the average temperature ranges from −16 °C in January to 22 °C in July. Average precipitation ranges from 250 to 390 mm/year; the plant life of the reserve is a rich collection herbaceous plants, with only 4% shrub cover. There are some meadow communities in moist hollows. Only 842 hectares in the reserve have woody vegetation alder and aspen. Scientists on the reserve have recorded 1,350 species of vascular plants, from 110 families; the animal life of the reserve reflects the location across several geographical zones, including steppe species, broad leaf forest species, species of semi-desert ecosystems. Scientists on the reserve have recorded 48 species of mammals, 193 of birds, 7 of reptiles, 5 of amphibians, 6 species of fish.

Rodents are the most common mammals. In May 2016, the Orenburg reserve opened a Center for the reintroduction of the Przewalski Horse; the program includes the addition of a fifth sector to the reserve. As a strict nature reserve, the Orenburg Reserve is closed to the general public, although scientists and those with'environmental education' purposes can make arrangements with park management for visits. There is an'ecotourist' route in each of the four sectors of the reserve, however; these are open to the public, but require permits to be obtained in advance, visits must be in the presence of a guide. The main office is in the city of Orenburg; the administration of the reserve is shared jointly with the Shaytan-Tau Nature Reserve List of Russian Nature Reserves National Parks of Russia Map of Orenburg Reserve, OpenStreetMap Map of Orenburg Reserve, ProtectedPlanet

Miskito grammar

This article provides a grammar sketch of the Miskito language, the language of the Miskito people of the Atlantic coast of Nicaragua and Honduras, a member of the Misumalpan language family. There exists a brief typological overview of the language that summarizes the language's most salient features of general typological interest in more technical terms; the exact status of vowel length is not clear. Word stress is on the first syllable of each word. Ligature is a useful term for describing a grammatical feature of Miskito traditionally referred to with less accuracy in the Miskito context as'construct'. A ligature is a morpheme which occurs when a noun is linked to some other element in the noun phrase. In Miskito, most of the elements that require the presence of ligature are ones that precede the head noun: Ligature takes a variety of forms: Some nouns take no ligature morpheme; the personal pronouns differentiate three persons and have an exclusive/inclusive distinction in the first person plural.

The general plural morpheme nani is added to form plurals. Use of these pronouns is optional when person is indexed in the possessed form, relational or verb group; the pronouns are not case-specific, may, under comparable conditions, be marked by the same postpositions as other noun phrases. Relationals are quasi-nouns expressing some relationship to their possessor complement. Many of the relationals perceivably originate in locatives of nouns designating parts of the body employed metaphorically to convey spatial or other relations. Finite forms include several tenses and moods, in each of which the person of the subject is marked by suffixes; the tenses themselves have characteristic suffixes. In addition to synthetic tenses, there is a considerable range of periphrastic tenses; these are formed with a non-finite form of the main verb followed by an auxiliary verb. Some of the synthetic tenses represent original periphrastic tense structures that have become welded into single words; this helps to explain why there are two different forms each in the present and future.

In addition to a subject index which form part of a verb's suffix, for transitive verbs the verb group includes an object index in the form of a preverbal particle marking the person of the object. The subject markers vary somewhat according to the tense, but the most usual forms are shown in the following table; the stem of a verb is obtained by removing the -aia suffix from the infinitive. Most verb stems end in a consonant, are conjugated as follows. Verbs whose stems end in i vary from the above paradigm in a few minor points. Bal-aia w-aia ` go', have an irregular Present I tense; the verb yabaia'give' is anomalous in a different way by having irregularly derived non-third-person object-indexing forms. The most irregular verb of all is the defective and irregular kaia'to be'; the range of aspectual and other notions that can be expressed is enlarged by the availability of various periphrastic constructions in which a verb acting as auxiliary is placed after the main verb. The conjugated component can take a variety of tenses, including periphrastic ones, the periphrases themselves may be combined.

Some representative examples of such periphrases follow: While no systematic case marking differentiates formally between subjects and objects, there exist certain option for achieving disambiguation. A system of specialized postpositions is used to identify topics and focused constituents: Most verbs are built up from a monosyllabic lexical root ending in a vowel or a single consonant, to which an extension or stem consonant is often added; the extensions correlate with transitivity: transitive stems have either -k- or -b-, while intransitive stems have -w-. There is a valency-decreasing verb-prefix ai- which, added to transitive stems, produces unergative, reciprocal or middle verbs. See the section on Derivation for examples. There are two major constructions which may be used to form relative clauses in Miskito, the'external head' strategy and the'internal head' strategy; as regards origin, the Miskito lexicon consists of the following principal components: words of native Miskito origin.

Some derivational affixes: Miskito language Miskito language Miskito Misumalpan languages Richter, Elke. Observaciones acerca del desarrollo lexical miskito en Nicaragua. Salamanca, Danilo. Gramática escolar del Miskito/Manual de Gramática del Miskito. Draft version on the Internet. Salamanca, Danilo. EI idioma miskito: estado de la lengua y características tipológicas. Ethnologue Diccionario Miskito by Danilo Salamanca Lengua Miskito — short page in Spanish containing several e