Gabrielle Hecht | |
---|---|
Born | 1965 (age 58–59) |
Academic background | |
Education | University of Pennsylvania (MA, PhD), MIT (BS) |
Academic work | |
Discipline | history |
Institutions | Stanford University |
Main interests | sociology of science |
Gabrielle Hecht (born 1965) is an American historian and Stanton Foundation Professor of Nuclear Security and Professor of History at Stanford University. She is known for her works on radioactive residues,mine waste,air pollution,and the Anthropocene in Africa. [1]
Uranium is a chemical element;it has 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 protons and 92 electrons,of which 6 are valence electrons. Uranium radioactively decays,usually by emitting an alpha particle. The half-life of this decay varies between 159,200 and 4.5 billion years for different isotopes,making them useful for dating the age of the Earth. 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 and slightly lower than that of gold or tungsten. It occurs naturally in low concentrations of a few parts per million in soil,rock and water,and is commercially extracted from uranium-bearing minerals such as uraninite.
Enriched uranium is a type of uranium in which the percent composition of uranium-235 has been increased through the process of isotope separation. Naturally occurring uranium is composed of three major isotopes:uranium-238,uranium-235,and uranium-234. 235U is the only nuclide existing in nature that is fissile with thermal neutrons.
Willard Frank Libby was an American physical chemist noted for his role in the 1949 development of radiocarbon dating,a process which revolutionized archaeology and palaeontology. For his contributions to the team that developed this process,Libby was awarded the Nobel Prize in Chemistry in 1960.
Martin Edward Hellman is an American cryptologist and mathematician,best known for his invention of public-key cryptography in cooperation with Whitfield Diffie and Ralph Merkle. Hellman is a longtime contributor to the computer privacy debate,and has applied risk analysis to a potential failure of nuclear deterrence.
The Nuclear Threat Initiative,generally referred to as NTI,is a non-profit organization located in Washington,D.C. The American foreign policy think tank was founded in 2001 by former U.S. Senator Sam Nunn and philanthropist Ted Turner and describes itself as a "nonprofit,nonpartisan global security organization focused on reducing nuclear and biological threats imperiling humanity."
Charles Thomas Fingar,is a professor at Stanford University. In 1986 Fingar left Stanford to join the State Department. In 2005,he moved to the Office of the Director of National Intelligence as the deputy director of National Intelligence for Analysis and concurrently served as the chairman of the National Intelligence Council until December 2008. In January 2009,he rejoined Stanford as a Payne Distinguished Lecturer in the Freeman Spogli Institute for International Studies.
Project 596 was the first nuclear weapons test conducted by the People's Republic of China,detonated on 16 October 1964,at the Lop Nur test site. It was a uranium-235 implosion fission device made from weapons-grade uranium (U-235) enriched in a gaseous diffusion plant in Lanzhou.
Eugene Rabinowitch was a Russian-born American biophysicist who is known for his work in photosynthesis and nuclear energy. He was a co-author of the Franck Report and a co-founder in 1945 of the Bulletin of the Atomic Scientists,a global security and public policy magazine,which he edited until his death.
The Dr. A. Q. Khan Research Laboratories,is a federally funded research and development laboratory located in Kahuta at a short distance from Rawalpindi in Punjab,Pakistan. Established in 1976,the laboratory is best known for its central role in Pakistan's nuclear weapons program and its understanding the nuclear science.
The uranium market,like all commodity markets,has a history of volatility,moving with the standard forces of supply and demand as well as geopolitical pressures. It has also evolved particularities of its own in response to the unique nature and use of uranium.
Uranium mining is the process of extraction of uranium ore from the ground. Over 50 thousand tons of uranium were produced in 2019. Kazakhstan,Canada,and Australia were the top three uranium producers,respectively,and together account for 68% of world production. Other countries producing more than 1,000 tons per year included Namibia,Niger,Russia,Uzbekistan,the United States,and China. Nearly all of the world's mined uranium is used to power nuclear power plants. Historically uranium was also used in applications such as uranium glass or ferrouranium but those applications have declined due to the radioactivity of uranium and are nowadays mostly supplied with a plentiful cheap supply of depleted uranium which is also used in uranium ammunition. In addition to being cheaper,depleted uranium is also less radioactive due to a lower content of short-lived 234
U and 235
U than natural uranium.
Frank N. von Hippel is an American physicist. He is Professor and Co-Director of Program on Science and Global Security at Princeton University and the Princeton School of Public and International Affairs.
Anti-nuclear organizations may oppose uranium mining,nuclear power,and/or nuclear weapons. Anti-nuclear groups have undertaken public protests and acts of civil disobedience which have included occupations of nuclear plant sites. Some of the most influential groups in the anti-nuclear movement have had members who were elite scientists,including several Nobel Laureates and many nuclear physicists.
Jim Falk is a physicist and academic researcher on science and technology studies.
Canada's Deadly Secret:Saskatchewan Uranium and the Global Nuclear System is a 2007 book by Jim Harding which chronicles the struggle over Saskatchewan's uranium mining,and demonstrates the negative impacts on Aboriginal rights and environmental health,and the effect of free trade. Harding argues that nuclear energy cannot mitigate global warming and that the "peaceful nuclear technology" does not exist. Helen Caldicott wrote the foreword to the book.
Uranium production is an important part of the African economy,with Niger,Namibia and South Africa creating up to 18% of the world's annual production. Many African countries produce uranium or have untapped uranium ore deposits.
William Taylor Miller was an American professor of organic chemistry at Cornell University. His experimental research included investigations into the mechanism of addition of halogens,especially fluorine,to hydrocarbons. His work focused primarily on the physical and chemical properties of fluorocarbons and chlorofluorocarbons,and the synthesis of novel electrophilic reagents.
The Fletcher School of Law and Diplomacy is the graduate school of international affairs of Tufts University,in Medford,Massachusetts. Fletcher is one of America's oldest graduate schools of international relations. As of 2017,the student body numbered around 230,of whom 36 percent were international students from 70 countries,and around a quarter were U.S. minorities.
Martha Crenshaw FBA is a political scientist who is prominent for her research on terrorism. She is professor of political science at Stanford University since 2007,as well as senior fellow at the Freeman Spogli Institute for International Studies (FSI) and Center for International Security and Cooperation (CISAC).
Gabrielle Calvocoressi is an American poet,editor,essayist,and professor.