Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 electrons, of which 6 are valence electrons. Uranium is weakly radioactive; the most common isotopes in natural uranium are uranium-238 and uranium-235. Uranium has the highest atomic weight of the primordially occurring elements, its density is about 70% higher than that of lead, lower than that of gold or tungsten. It occurs in low concentrations of a few parts per million in soil and water, is commercially extracted from uranium-bearing minerals such as uraninite. In nature, uranium is found as uranium-238, uranium-235, a small amount of uranium-234. Uranium decays by emitting an alpha particle; the half-life of uranium-238 is about 4.47 billion years and that of uranium-235 is 704 million years, making them useful in dating the age of the Earth. Many contemporary uses of uranium exploit its unique nuclear properties. Uranium-235 is the only occurring fissile isotope, which makes it used in nuclear power plants and nuclear weapons.
However, because of the tiny amounts found in nature, uranium needs to undergo enrichment so that enough uranium-235 is present. Uranium-238 is fissionable by fast neutrons, is fertile, meaning it can be transmuted to fissile plutonium-239 in a nuclear reactor. Another fissile isotope, uranium-233, can be produced from natural thorium and is important in nuclear technology. Uranium-238 has a small probability for spontaneous fission or induced fission with fast neutrons. In sufficient concentration, these isotopes maintain a sustained nuclear chain reaction; this generates the heat in nuclear power reactors, produces the fissile material for nuclear weapons. Depleted uranium is used in kinetic energy penetrators and armor plating. Uranium is used as a colorant in uranium glass. Uranium glass fluoresces green in ultraviolet light, it was used for tinting and shading in early photography. The 1789 discovery of uranium in the mineral pitchblende is credited to Martin Heinrich Klaproth, who named the new element after the discovered planet Uranus.
Eugène-Melchior Péligot was the first person to isolate the metal and its radioactive properties were discovered in 1896 by Henri Becquerel. Research by Otto Hahn, Lise Meitner, Enrico Fermi and others, such as J. Robert Oppenheimer starting in 1934 led to its use as a fuel in the nuclear power industry and in Little Boy, the first nuclear weapon used in war. An ensuing arms race during the Cold War between the United States and the Soviet Union produced tens of thousands of nuclear weapons that used uranium metal and uranium-derived plutonium-239; the security of those weapons and their fissile material following the breakup of the Soviet Union in 1991 is an ongoing concern for public health and safety. See Nuclear proliferation; when refined, uranium is a weakly radioactive metal. It has a Mohs hardness of 6, sufficient to scratch glass and equal to that of titanium, rhodium and niobium, it is malleable, ductile paramagnetic electropositive and a poor electrical conductor. Uranium metal has a high density of 19.1 g/cm3, denser than lead, but less dense than tungsten and gold.
Uranium metal reacts with all non-metal elements and their compounds, with reactivity increasing with temperature. Hydrochloric and nitric acids dissolve uranium, but non-oxidizing acids other than hydrochloric acid attack the element slowly; when finely divided, it can react with cold water. Uranium in ores is extracted chemically and converted into uranium dioxide or other chemical forms usable in industry. Uranium-235 was the first isotope, found to be fissile. Other occurring isotopes are fissionable, but not fissile. On bombardment with slow neutrons, its uranium-235 isotope will most of the time divide into two smaller nuclei, releasing nuclear binding energy and more neutrons. If too many of these neutrons are absorbed by other uranium-235 nuclei, a nuclear chain reaction occurs that results in a burst of heat or an explosion. In a nuclear reactor, such a chain reaction is slowed and controlled by a neutron poison, absorbing some of the free neutrons; such neutron absorbent materials are part of reactor control rods.
As little as 15 lb of uranium-235 can be used to make an atomic bomb. The first nuclear bomb used in war, Little Boy, relied on uranium fission, but the first nuclear explosive and the bomb that destroyed Nagasaki were both plutonium bombs. Uranium metal has three allotropic forms: α stable up to 668 °C. Orthorhombic, space group No. 63, lattice parameters a = 285.4 pm, b = 587 pm, c = 495.5 pm. Β stable from 668 °C to 775 °C. Tetragonal, space group P42/mnm, P42nm, or P4n2, lattice parameters a = 565.6 pm, b = c = 1075.9 pm. Γ from 775 °C to melting point—this is the most malleable and ductile state. Body-centered cubic, lattice parameter a = 352.4 pm. Th
'Taman Tasik Semenyih or less known as Semenyih Lake Park is a university town adjacent to the University of Nottingham Malaysia Campus located in Selangor, Malaysia. Houses in this neighbourhood are owned by a few landlords who rent out houses to students. Rents are comparatively higher than those of the general area. Most rentable homes are dilapidated, furnished poorly and suffering from animal infestation. Due to the developing state of the campus and general area, basic services are poor at best. Fiber internet is not available in this area, cellphone reception is poor. However, as of the year 2016 TELEKOM MALAYSIA is now operating the fiber internet and mobile services is now available. Taman Tasik Semenyih was developed by a low profile Malaysian developer, Bandar Tasik Semenyih Sdn Bhd or BTS Land Capital as an out of town, low density residential development meant for low to middle income people who works in Klang Valley. In the beginning, the town failed to grow as envision, with most of the residential and commercial lots undeveloped.
However, following the inception and opening of the adjacent university campus. The town has shifted in role and now prominently houses students from the university in the form of off-campus accommodation. Commercial activity is increase albeit at a slow rate with much of the commercial area still void of any activity. Most of the area is made up of low density residential housing with pockets of medium-density housing. In the early 2010s, with the boom of short-term student housing, numerous house are being converted into student hostels. A three bed room landed house is expanded upon and made into 8-10 room hostel; this has raised the issue of noise pollution and general health and safety risk. There is general worry that sewage lines within the estate may not be able to cope with the increasing amounts of solid waste being made. However, since 2016 Indah Water Sewerage treatment plant located along Jalan TTS1/1 have been upgraded and extended to cope with new developments in the area. There is a small commercial area located to the south of the town.
Due to a lack of economic activity and patronage, most of the shops are closed and the area can be classified as a ghost town. A small drain runs along the major arterial road of this town. With the rise in student population, more restaurants have started appearing along this commercial area to the shophouses located adjacent to the main roads. Restaurants are offering middle eastern, south Asian or local cuisine, with most of the international ones offering delivery service. Food prices are higher than average. Taman Tasik Semenyih can be further classified into 7 zones: An intended high income area, of bungalow land lots surrounding a man-made lake; this area comprises 52 bungalow lots ranging from 12,000 sq above. This is the zone with one family club house with a cafeteria open to public, a 20-acre public lake garden and a golf driving range. A premium 3 block of 4-storey walk up apartments are located within this area. Designed and built for University of Nottingham Malaysia off-campus students.
This area is served by a handful of buses and taxis from the university. Lower-medium cost terrace houses fill this small area, a number of houses of this area has been converted to student housing, due to the dense nature of hostel occupancy, parking shortage is an increasing problem. Bungalow lots filled with single storey bungalows; some of these bungalows have been renovated and expanded into 2 storey dwellings and some into student hostels. There at least 5 fraternity and sorority houses located within the area. One of them, dubbed the "white house" was a former church converted into a hostel. However, since Sept 2013, the "white house" was closed; this was due to the widespread cases of theft and break-ins. A mixture of bungalow houses and terrace dwellings student populated and noisy at night; the deeper parts of this zone is gated. Being a middle income area, this area features, a sizable park, a surau, is promoted as a wifi precinct; the zone of nearest access to campus due to presence of pedestrian bridge.
Terrace house with lines of 2 storey bungalows, due to location, one of the popular, inflated rent areas. Houses near to the bridge has been converted to private student hostels. A converted house in this area tend to have 10-24 beds. Due to the noisy, raucous behaviour of students and the chance to cash in on student rentals there has been a mass exodus of family homes, with estimates of 39.4% homes lived by families. While student population over the academic year making up an excess of 62.1% of the living population. EDU Square is a collective of semi detached and interlinked terrace buildings, purpose built as student hostels; these were built by BTS Land Capital. Some of these are managed by varying parties. Rent here is comparatively expensive compared to regular TTS accommodation, but is viewed as being safer due to the use of permanent private security personnel on-site. Though crime index seems to suggest otherwise. Low cost terrace area. Unlike the other areas this area, this area is not popular with students and family home still account for 83.4% of the houses.
Predominantly a Malay area, this area is made up of low-income residents, ethnic Malay students and staff. The newest area with upper-medium cost semi detached houses, with inflated rent, comparable to those in TTS 5; this zone is located at the deep end of the arterial road and is opinion-ed as being situated too far from campus. Unlike other areas, which have vestiges
State Route 236 is a state highway located in extreme southern Maine within York County. It begins at State Route 103 in Kittery and runs 15.72 miles north, terminating at State Route 9 in Berwick. Between Kittery and South Berwick, SR 236 is known as the Harold L. Dow Highway; the highway runs parallel to the New Hampshire border over its entire length. The southern terminus of SR 236 is at the intersection of SR 103, Woodlawn Avenue, Shapleigh Road in Kittery, near the Portsmouth Naval Shipyard, it follows Shapleigh Road and Rogers Road to the Kittery Traffic Circle, where it connects to US 1, US 1 Bypass, Old Post Road. The rotary marks the southern end of the Dow Highway. SR 236 has partial interchanges with US 1 Bypass and I-95 continues northwest along the former right-of-way of the B&M Railroad until intersecting SR 4 in South Berwick at the northern end of the Dow Highway. SR 236 is cosigned with SR 4 in downtown South Berwick splits off to follow Berwick Road into downtown Berwick along Allen Street to its northern terminus at SR 9 1,200 feet east of the New Hampshire state line.
To the west, SR 9 crosses the Salmon Falls River into Somersworth, New Hampshire and continues west as NH 9 / NH 236. NH 236 is a westward extension of SR 236 through downtown Somersworth to NH 108 south of Rochester. Though it does not directly connect to SR 236 as signed, the two routes are connected by SR 9; the northern section of SR 236, from Gould's Corner in Eliot to downtown Berwick, was designated in 1929 as part of SR 103. That route was truncated to its current terminus in 1957, its northern segment was re-designated as SR 236. Both SR 103 and SR 236 have a terminus at the other route. Most of the southern part of SR 236 between I-95 in Kittery and SR 91 in South Berwick was built in 1956 on the former right-of-way of the B&M Railroad after service was discontinued and the tracks removed four years earlier. While railroad service has disappeared, SR 236 is a busy commuter corridor connecting to I-95, the Portsmouth Naval Shipyard, downtown Portsmouth; the entire route is in York County