Iron is a chemical element with symbol Fe and atomic number 26. It is a metal that belongs to group 8 of the periodic table, it is by mass the most common element on Earth, forming much of Earth's inner core. It is the fourth most common element in the Earth's crust. In its metallic state, iron is rare in the Earth's crust, limited to deposition by meteorites. Iron ores, by contrast, are among the most abundant in the Earth's crust, although extracting usable metal from them requires kilns or furnaces capable of reaching 1,500 °C or higher, about 500 °C higher than what is enough to smelt copper. Humans started to master that process in Eurasia only about 2000 BCE, the use of iron tools and weapons began to displace copper alloys, in some regions, only around 1200 BCE; that event is considered the transition from the Bronze Age to the Iron Age. In the modern world, iron alloys, such as steel, cast iron and special steels are by far the most common industrial metals, because of their high mechanical properties and low cost.
Pristine and smooth pure iron surfaces are mirror-like silvery-gray. However, iron reacts with oxygen and water to give brown to black hydrated iron oxides known as rust. Unlike the oxides of some other metals, that form passivating layers, rust occupies more volume than the metal and thus flakes off, exposing fresh surfaces for corrosion; the body of an adult human contains about 4 grams of iron in hemoglobin and myoglobin. These two proteins play essential roles in vertebrate metabolism oxygen transport by blood and oxygen storage in muscles. To maintain the necessary levels, human iron metabolism requires a minimum of iron in the diet. Iron is the metal at the active site of many important redox enzymes dealing with cellular respiration and oxidation and reduction in plants and animals. Chemically, the most common oxidation states of iron are iron. Iron shares many properties of other transition metals, including the other group 8 elements and osmium. Iron forms compounds in a wide range of oxidation states, −2 to +7.
Iron forms many coordination compounds. At least four allotropes of iron are known, conventionally denoted α, γ, δ, ε; the first three forms are observed at ordinary pressures. As molten iron cools past its freezing point of 1538 °C, it crystallizes into its δ allotrope, which has a body-centered cubic crystal structure; as it cools further to 1394 °C, it changes to its γ-iron allotrope, a face-centered cubic crystal structure, or austenite. At 912 °C and below, the crystal structure again becomes the bcc α-iron allotrope; the physical properties of iron at high pressures and temperatures have been studied extensively, because of their relevance to theories about the cores of the Earth and other planets. Above 10 GPa and temperatures of a few hundred kelvin or less, α-iron changes into another hexagonal close-packed structure, known as ε-iron; the higher-temperature γ-phase changes into ε-iron, but does so at higher pressure. Some controversial experimental evidence exists for a stable β phase at pressures above 50 GPa and temperatures of at least 1500 K.
It is supposed to have a double hcp structure. The inner core of the Earth is presumed to consist of an iron-nickel alloy with ε structure; the melting and boiling points of iron, along with its enthalpy of atomization, are lower than those of the earlier 3d elements from scandium to chromium, showing the lessened contribution of the 3d electrons to metallic bonding as they are attracted more and more into the inert core by the nucleus. This same trend appears for ruthenium but not osmium; the melting point of iron is experimentally well defined for pressures less than 50 GPa. For greater pressures, published data still varies by tens of gigapascals and over a thousand kelvin. Below its Curie point of 770 °C, α-iron changes from paramagnetic to ferromagnetic: the spins of the two unpaired electrons in each atom align with the spins of its neighbors, creating an overall magnetic field; this happens because the orbitals of those two electrons do not point toward neighboring atoms in the lattice, therefore are not involved in metallic bonding.
In the absence of an external source of magnetic field, the atoms get spontaneously partitioned into magnetic domains, about 10 micrometers across, such that the atoms in each domain have parallel spins, but different domains have other orientations. Thus a macroscopic piece of iron will have a nearly zero overall magnetic field. Application of an external magnetic field causes the domains that are magnetized in the same general direction to grow at the expense of adjacent ones that point in other directions, reinforcing the external field; this effect is exploited in devices that needs to channel magnetic fields, such as electrical transformers, magnetic recording heads, electric motors. Impurities, lattice defects, or grain and particle boundaries can "pin" the domains in the new positions, so that the effect persists after the external field is removed -- thus tur
Jan Kaplický was a Neofuturistic Czech architect who spent a significant part of his life in the United Kingdom. He was the leading architect behind Future Systems, he was best known for the neofuturistic Selfridges Building in Birmingham and the Media Centre at Lord's Cricket Ground in London. Jan Kaplický, the only child of a sculptor and a botanical illustrator, was born on 18 April 1937 in Prague and grew up in a suburb of Prague called Ořechovka. Between 1956 and 1962 he studied at the College of Applied Arts and Architecture and Design in Prague, receiving a Diploma in Architecture, he worked in private practice in Czechoslovakia between 1964 and 1968. In the wake of the Prague Spring, the Soviet invasion of Czechoslovakia, he escaped to London in September 1968 with fellow architect Jaroslav Vokoun carrying only US$100 and a few pairs of socks. In 1969 in London he met again Eva Jiřičná whom he had known in Prague, who became his girlfriend. In England, Kaplický first worked for Denys Lasdun and Partners obtained employment with the office of Renzo Piano and Richard Rogers, where he worked on DRU extension at Aybrook Street and helping to develop the design for the Centre Georges Pompidou in Paris by joining the team of more than 30 strong.
When the practice relocated to Paris, he was unable to follow as at that time he still did not have a British passport. After working with Jiřičná, a short spell at Spencer and Webster, Associates, he joined Foster Associates, now Foster and Partners. At the same time, in 1979 Kaplický set up his own architectural think tank called Future Systems with David Nixon, began to develop an architectural style that combined organic forms with high tech futurism. Among the drawings he made were structures orbiting the earth built by robots, weekend houses resembling survival capsules that could be transported by helicopter, home interiors that could be manipulated. In the 1980s his design for the Grand Buildings in Trafalgar Square, was a free-form monocoque structure pierced by portholes. Kaplický told BusinessWeek in 2005: "Where is it written that buildings have to be boxes? People aren't boxes."Amanda Levete joined Future Systems as a partner in 1989. Kaplický and Levete were a couple for 15 years.
Although they divorced in 2006, they continued their professional association in the architectural practice, saying that the separation strengthened their working relationship. Although Kaplický was a finalist for the Prince Philip Prize for designer of the year in 1991, for the first 15 years of its existence Future Systems received few commissions, it was not until 1994 that the company was commissioned to build the new media centre at Lord's Cricket Ground which won the Royal Institute of British Architects Stirling Prize – considered the most prestigious architecture award in the UK – in 1999 and the World Architecture Awards in 2001. Kaplický considered the media centre "my favourite creation", saying, "It is something, revolutionary in many areas – a real technical achievement – but above all, the people operating inside it have said:'We love it,' and that's great." In 2000, he was made an Honourable Fellow of RIBA. Future Systems' next major project, the iconic Selfridges Building in the Bull Ring in Birmingham, won seven awards, including the RIBA Award for Architecture 2004.
That year, Kaplický was the subject of a Czech documentary entitled Profil. In 2007, Kaplický won the design competition for the new Czech National Library building; this was to have been his first major building in his home country, he said the project was the most important event in his life. However, the design for the building, resembling a green and purple blob and nicknamed by locals "the Octopus", was criticised. President of the Czech Republic Václav Klaus was overheard saying he would be willing to prevent the building going ahead with his own body. Pavel Bém, the Civic Democrat Mayor of Prague, supported the design when it was selected but become hostile to it, saying that the City Council of Prague, dominated by the Civil Democratic Party, would not allow the Octopus to be built as it would ruin Prague's panorama. Vlastimil Jezek, a former director of the Library, regarded Kaplický as "another protagonist of Czech culture, crushed by Czech narrow-mindedness." Although the design was dropped, Kaplický remained hopeful that the building would be built through funds from a private foundation established for this purpose.
Apart from his design work, Kaplický was active in the education of architects. He taught from 1982 to 1988 at the Architectural Association School of Architecture, the oldest independent architectural school in the UK, in 1992 at the School of Architecture in Bordeaux and at the Design Workshop of the Technische Universität Berlin, he was an external examiner for the Architectural Association between 1995 and 1998, in 2000 was an assessor for the Domus Awards of the B. B. J. Competition in Milan. In October 2008, news broke that Kaplický and Levete intended to go their separate ways after having collaborated professionally for 20 years. Kaplický was due to keep the Future Systems practice name. Towards the end of his life, Kaplický began to spend more time in the Czech Republic, where he was awaiting the construction of the Czech National Library and where his design for the Congress and Concert Ha
The Preventing Sex Trafficking and Strengthening Families Act is a US bill that would address federal adoption incentives and would amend the Social Security Act to require the state plan for foster care and adoption assistance to demonstrate that the state agency has developed policies and procedures with respect to the children it is working, which are a victim of sex trafficking or a severe form of trafficking in persons. The bill furthermore requires states to implement the 2008 UIFSA version, required so the 2007 Hague Maintenance Convention can be ratified by the US; the bill was introduced into the United States House of Representatives during the 113th United States Congress. The bill is a compromise measure made up of pieces of six other bills. Adoptions in the United States may be either domestic or from another country. Domestic adoptions can be arranged either through adoption agency or independently. Adoption agencies must be licensed by the state; the U. S. government maintains a website, Child Welfare Information Gateway, which lists each state's licensed agencies.
There are both public adoption agencies. Private adoption agencies focus on infant adoptions, while public adoption agencies help find homes for waiting children, many of them presently in foster care and in need of a permanent loving home. To assist in the adoption of waiting children, there is a U. S. government-affiliated website, AdoptUSKids.org, assisting in sharing information about these children with potential adoptive parents. The North American Council on Adoptable Children provides information on financial assistance to adoptive parents when adopting a child with special needs. Independent adoptions are arranged by attorneys and involve newborn children. 55% of all U. S. newborn adoptions are completed via independent adoption. The 2000 census was the first census; the estimated number of children adopted in the year 2000 was over 128,000, bringing the total U. S. population of adopted children to 2,058,915. In 2008 the number of children adopted increased to nearly 136,000. Provisions for recovery of child support are a subject of state-law in the US.
For the international recovery of child support, bilateral agreements are in place between the US and a number of countries, certain US States have bilateral agreements with countries in place. In 2007 the Hague Maintenance Convention was adopted within the framework of the Hague Conference on Private International Law, aimed at recovery of international maintenance; the convention requires countries to set up Central Authorities to coordinate recovery of maintenance, provides for recognition and enforcement measures of judicial maintenance decisions. The US was the first to sign the convention in 2007 and the Senate approved it several years later. Ratification by the US could not take place. Meanwhile the agreement has entered into force with respect to the European Union and 5 other European countries: Albania and Herzegovina, Norway and Ukraine; this summary is based on the summary provided by the Congressional Research Service, a public domain source. The Preventing Sex Trafficking and Strengthening Families Act would amend part E of title IV of the Social Security Act to require the state plan for foster care and adoption assistance to demonstrate that the state agency has developed policies and procedures for identifying, documenting in agency records, determining appropriate services with respect to, any child or youth over whom the state agency has responsibility for placement, care, or supervision who the state has reasonable cause to believe is, or is at risk of being, a victim of sex trafficking or a severe form of trafficking in persons.
The bill would authorize a state, at its option, to identify and document any individual under age 26 without regard to whether the individual is or was in foster care under state responsibility. The bill would add as state plan requirements: the reporting to law enforcement authorities of instances of sex trafficking, as well as the locating of and responding to children who have run away from foster care; the bill would include sex trafficking data in the adoption and foster care analysis and reporting system. The bill would direct the state agency to report information on missing or abducted children or youth to law enforcement authorities for entry into the National Crime Information Center database of the Federal Bureau of Investigation and to the National Center for Missing and Exploited Children; the bill would require the designated state authority or authorities to: develop a reasonable and prudent parent standard for the child's participation in age or developmentally appropriate extracurricular, enrichment and social activities.
The bill would direct the Secretary to provide assistance to states on best practices for devising strategies to assist foster parents in applying a reasonable and prudent parent standard in a specified manner. The bill would make it a purpose of the John H. Chafee Foster Care Independence Program to ensure that children who are to remain in foster care until age 18 have regular, ongoing opportunities to engage in age or developmentally-appropriate activities. Authorizes increased appropriations for the program beginning in FY2020; the bill would limit to children age 16 or older the option, in an initial permanency hearing, of being placed in a planned perman