Problem: What is the answer for the question: What was the full name of the person who attempted to simplify the problem by using the fast neutrons produced by fission? from the following article ? At Birmingham, Oliphant's team had reached a different conclusion. Oliphant had delegated the task to two German refugee scientists, Rudolf Peierls and Otto Frisch, who could not work on Oliphant's radar project because they were enemy aliens and therefore lacked the necessary security clearance. Francis Perrin had calculated the critical mass of uranium to be about 40 tonnes (39 long tons; 44 short tons). He reckoned that if a neutron reflector were placed around it, this might be reduced to 12 tonnes (12 long tons; 13 short tons). Peierls attempted to simplify the problem by using the fast neutrons produced by fission, thus omitting consideration of moderator. He too calculated the critical mass of a sphere of uranium in a theoretical paper written in 1939 to be "of the order of tons".Peierls knew the importance of the size of the critical mass that would allow a chain reaction to take place and its practical significance. In the interior of a critical mass sphere, neutrons are spontaneously produced by the fissionable material. A very small portion of these neutrons are colliding with other nuclei, while a larger portion of the neutrons are escaping through the surface of the sphere. Peierls calculated the equilibrium of the system, where the number of neutrons being produced equalled the number escaping.Niels Bohr had theorised that the rare uranium-235 isotope, which makes up only about 0.7% of natural uranium, was primarily responsible for fission with fast neutrons, although this was not yet universally accepted. Frisch and Peierls were thus able to revise their initial estimate of critical mass needed for nuclear fission in uranium to be substantially less than previously assumed. They estimated a metallic sphere of uranium-235 with a radius of 2.1 centimetres (0.83 in) could suffice. This amount represented approximately 1 kilogram (2.2 lb) of uranium-235. These results led to the FrischPeierls memorandum, which was the initial step in the development of the nuclear arms programme in Britain. This...

A: Rudolf Peierls
Problem: Given the question: What is the answer for the question: What is the last name of the person who worked for the Institute of Archaeology in London? from the following article ? Vere Gordon Childe (14 April 1892 19 October 1957) was an Australian archaeologist who specialized in the study of European prehistory. He spent most of his life in the United Kingdom, working as an academic for the University of Edinburgh and then the Institute of Archaeology, London, and wrote twenty-six books during his career. Initially an early proponent of culture-historical archaeology, he later became the first exponent of Marxist archaeology in the Western world. Born in Sydney to a middle-class English migrant family, Childe studied classics at the University of Sydney before moving to England to study classical archaeology at the University of Oxford. There, he embraced the socialist movement and campaigned against the First World War, viewing it as a conflict waged by competing imperialists to the detriment of Europe's working class. Returning to Australia in 1917, he was prevented from working in academia because of his socialist activism, instead working for the Labor Party as the private secretary of the politician John Storey. Growing critical of Labor, he wrote an analysis of their policies and joined the far-left Industrial Workers of the World. Emigrating to London in 1921, he became librarian of the Royal Anthropological Institute and journeyed across Europe to pursue his research into the continent's prehistory, publishing his findings in academic papers and books. In doing so he introduced the continental European concept of an archaeological culturethe idea that a recurring assemblage of artefacts demarcates a distinct cultural groupto the British archaeological community.
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The answer is:
Childe
[Q]: What is the answer for the question: What trade networks could the city participate in because of Takalik Abaj's link to long-distance Maya trade routes? from the following article ? Tak'alik Ab'aj (; Mayan pronunciation: [takalik a'a] (listen); Spanish: [takalik aax]) is a pre-Columbian archaeological site in Guatemala. It was formerly known as Abaj Takalik; its ancient name may have been Kooja. It is one of several Mesoamerican sites with both Olmec and Maya features. The site flourished in the Preclassic and Classic periods, from the 9th century BC through to at least the 10th century AD, and was an important centre of commerce, trading with Kaminaljuyu and Chocola. Investigations have revealed that it is one of the largest sites with sculptured monuments on the Pacific coastal plain. Olmec-style sculptures include a possible colossal head, petroglyphs and others. The site has one of the greatest concentrations of Olmec-style sculpture outside of the Gulf of Mexico.Takalik Abaj is representative of the first blossoming of Maya culture that had occurred by about 400 BC. The site includes a Maya royal tomb and examples of Maya hieroglyphic inscriptions that are among the earliest from the Maya region. Excavation is continuing at the site; the monumental architecture and persistent tradition of sculpture in a variety of styles suggest the site was of some importance.Finds from the site indicate contact with the distant metropolis of Teotihuacan in the Valley of Mexico and imply that Takalik Abaj was conquered by it or its allies. Takalik Abaj was linked to long-distance Maya trade routes that shifted over time but allowed the city to participate in a trade network that included the Guatemalan highlands and the Pacific coastal plain from Mexico to El Salvador. Takalik Abaj was a sizeable city with the principal architecture clustered into four main groups spread across nine terraces. While some of these were natural features, others were artificial constructions requiring an enormous investment in labour and materials. The site featured a sophisticated water drainage system and a wealth of sculptured monuments.
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[A]:
Guatemalan highlands