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Orders Of Magnitude (radiation)
Recognized effects of higher acute radiation doses are described in more detail in the article on radiation poisoning. Although the International System of Units (SI) defines the sievert (Sv) as the unit of radiation dose equivalent, chronic radiation levels and standards are still often given in units of millirems (mrem), where 1 mrem equals 1/1000 of a rem and 1 rem equals 0.01 Sv. Light radiation sickness begins at about 50–100 rad (0.5–1 gray (Gy), 0.5–1 Sv, 50–100 rem, 50,000–100,000 mrem). The following table includes some dosages for comparison purposes, using millisieverts (mSv) (one thousandth of a sievert). The concept of radiation hormesis is relevant to this table – radiation hormesis is a hypothesis stating that the effects of a given acute dose may differ from the effects of an equal fractionated dose. Thus 100 mSv is considered twice in the table below – once as received over a 5-year period, and once as an acute dose, receive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Absorbed Dose
Absorbed dose is a dose quantity which is the measure of the energy deposited in matter by ionizing radiation per unit mass. Absorbed dose is used in the calculation of dose uptake in living tissue in both radiation protection (reduction of harmful effects), and radiology (potential beneficial effects for example in cancer treatment). It is also used to directly compare the effect of radiation on inanimate matter such as in radiation hardening. The SI unit of measure is the gray (Gy), which is defined as one Joule of energy absorbed per kilogram of matter. The older, non-SI CGS unit rad, is sometimes also used, predominantly in the USA. Deterministic effects Conventionally, in radiation protection, unmodified absorbed dose is only used for indicating the immediate health effects due to high levels of acute dose. These are tissue effects, such as in acute radiation syndrome, which are also known as deterministic effects. These are effects which are certain to happen in a short ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Three Mile Island Accident
The Three Mile Island accident was a partial meltdown of the Three Mile Island, Unit 2 (TMI-2) reactor in Pennsylvania, United States. It began at 4 a.m. on March 28, 1979. It is the most significant accident in U.S. commercial nuclear power plant history. On the seven-point International Nuclear Event Scale, it is rated Level 5 – Accident with Wider Consequences. The accident began with failures in the non-nuclear secondary system followed by a stuck-open pilot-operated relief valve (PORV) in the primary system that allowed large amounts of nuclear reactor coolant to escape. The mechanical failures were compounded by the initial failure of plant operators to recognize the situation as a loss-of-coolant accident (LOCA). The failure of operators is attributed to the out-of-the-loop performance problem. TMI training and procedures left operators and management ill-prepared for the deteriorating situation. During the event these inadequacies were compounded by design ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Health Threat From Cosmic Rays
Health threats from cosmic rays are the dangers posed by cosmic rays to astronauts on interplanetary missions or any missions that venture through the Van-Allen Belts or outside the Earth's magnetosphere. They are one of the greatest barriers standing in the way of plans for interplanetary travel by crewed spacecraft, but space radiation health risks also occur for missions in low Earth orbit such as the International Space Station (ISS). In October 2015, the NASA Office of Inspector General issued a health hazards report related to space exploration, including a human mission to Mars. The deep-space radiation environment The radiation environment of deep space is different from that on the Earth's surface or in low Earth orbit, due to the much larger flux of high-energy galactic cosmic rays (GCRs), along with radiation from solar proton events (SPEs) and the radiation belts. Galactic cosmic rays (GCRs) consist of high energy protons (85%), alpha particles (14%) and oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Cosmic Ray Conference
The International Cosmic Ray Conference, or ICRC, is a physics conference organized biennially by thCommission C4 (Astroparticle Physics) of the International Union of Pure and Applied Physics (IUPAP) since 1947, where physicists from the whole world present the results of their research in Astroparticle Physics. The main topics of Astroparticle Physics are *Cosmic Ray Physics, *Gamma-Ray Astronomy, *Neutrino Astronomy, *Dark Matter Physics, * Multi-Messenger Astrophysics, *Solar and Heliospheric Physics, *Astroparticle Physics Theory and Models, *Experimental Methods, Techniques and Instrumentation and *Outreach & Education in Astroparticle Physics. As part of the opening ceremonies, The O'Ceallaigh Medal is presented to a researcher who has made distinguished contributions to Cosmic Ray Physics.(webpage) * 33rd ICRC : July 2–9, 2013, Rio de Janeiro, Brazilwebpage * 32nd ICRC : August 11–18, 2011, Beijing, Chinawebpage * 31st ICRC : July 7–15, 2009, Łódź, Polandwe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ramsar, Mazandaran
, sports_nickname = , motto = The Paradise on Earth (Behesht-e rooy-e Zamin) , image_skyline = , image_caption = , image_seal = , image_map = , mapsize = , map_caption = , settlement_type = City , coordinates = , pushpin_map = Iran#Caspian Sea , pushpin_label_position = bottom , pushpin_map_caption = Location of Ramsar in Iran , pushpin_mapsize = , subdivision_type = Country , subdivision_name = Iran , subdivision_type1 = Province , subdivision_name1 = Mazandaran , subdivision_type2 = County , subdivision_name2 = Ramsar , subdivision_type3 = Bakhsh , subdivision_name3 = Central , leader_title = Mayor (Ŝahrdār) , leader_name = Mohsen Morradi , established_title = , established_date = 1943 , are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gray (unit)
The gray (symbol: Gy) is the unit of ionizing radiation dose in the International System of Units (SI), defined as the absorption of one joule of radiation energy per kilogram of matter. It is used as a unit of the radiation quantity absorbed dose that measures the energy deposited by ionizing radiation in a unit mass of matter being irradiated, and is used for measuring the delivered dose in radiotherapy, food irradiation and radiation sterilization. It is important in predicting likely acute health effects, such as acute radiation syndrome and is used to calculate equivalent dose using the sievert, which is a measure of the stochastic health effect on the human body. The gray is also used in radiation metrology as a unit of the radiation quantity kerma; defined as the sum of the initial kinetic energies of all the charged particles liberated by uncharged ionizing radiation in a sample of matter per unit mass. The gray is an important unit in ionising radiation measuremen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guarapari
Guarapari is a coastal town of Espírito Santo, Brazil, a popular tourist destination. Its beach is famous for the high natural radioactivity level of its sand. Location Guarapari is a part of Greater Vitoria, 47 km south of the state capital Vitória. Its population is 126,701 (2020) and its area is 592 km². It is a well-known tourist destination, known for its curving white sand beaches backed by commercial development, which extend southward to Nova Guarapari and Meaípe. With its heavily built-up coastline like Vila Velha and Vitória, it caters heavily to seasonal tourists, and consequently has quite a dramatic seasonal population fluctuation. The municipality contains the Concha d'Ostra Sustainable Development Reserve, established in 2003 to protect the mangroves of the Bay of Guarapari. It also contains the Paulo César Vinha State Park, which protects an area of dunes, lagoons and marshes along the Atlantic shore. Formerly called the Setiba nature reserve, it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chernobyl Disaster
The Chernobyl disaster was a nuclear accident that occurred on 26 April 1986 at the No. 4 reactor in the Chernobyl Nuclear Power Plant, near the city of Pripyat in the north of the Ukrainian SSR in the Soviet Union. It is one of only two nuclear energy accidents rated at seven—the maximum severity—on the International Nuclear Event Scale, the other being the 2011 Fukushima nuclear disaster in Japan. The initial emergency response, together with later decontamination of the environment, involved more than 500,000 personnel and cost an estimated 18 billion roubles—roughly US$68 billion in 2019, adjusted for inflation. The accident occurred during a safety test meant to measure the ability of the steam turbine to power the emergency feedwater pumps of an RBMK-type nuclear reactor in the event of a simultaneous loss of external power and major coolant leak. During a planned decrease of reactor power in preparation for the test, the operators accidentally dropp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ural Mountains
The Ural Mountains ( ; rus, Ура́льские го́ры, r=Uralskiye gory, p=ʊˈralʲskʲɪjə ˈɡorɨ; ba, Урал тауҙары) or simply the Urals, are a mountain range that runs approximately from north to south through western Russia, from the coast of the Arctic Ocean to the river Ural and northwestern Kazakhstan.Ural Mountains Encyclopædia Britannica on-line The mountain range forms part of the conventional boundary between the regions of and |
Positron Emission Tomography
Positron emission tomography (PET) is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in Metabolism, metabolic processes, and in other physiological activities including blood flow, regional chemical composition, and absorption. Different tracers are used for various imaging purposes, depending on the target process within the body. For example, 18F-FDG, -FDG is commonly used to detect cancer, Sodium fluoride#Medical imaging, NaF is widely used for detecting bone formation, and Isotopes of oxygen#Oxygen-15, oxygen-15 is sometimes used to measure blood flow. PET is a common medical imaging, imaging technique, a Scintigraphy#Process, medical scintillography technique used in nuclear medicine. A radiopharmaceutical, radiopharmaceutical — a radioisotope attached to a drug — is injected into the body as a radioactive tracer, tracer. When the radiopharmaceutical undergoes beta plus decay, a positron is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Santa Fe, New Mexico
Santa Fe ( ; , Spanish for 'Holy Faith'; tew, Oghá P'o'oge, Tewa for 'white shell water place'; tiw, Hulp'ó'ona, label=Tiwa language, Northern Tiwa; nv, Yootó, Navajo for 'bead + water place') is the capital of the U.S. state of New Mexico. The name “Santa Fe” means 'Holy Faith' in Spanish, and the city's full name as founded remains ('The Royal Town of the Holy Faith of Saint Francis of Assisi'). With a population of 87,505 at the 2020 United States census, 2020 census, it is the List of municipalities in New Mexico, fourth-largest city in New Mexico. It is also the county seat of Santa Fe County. Its metropolitan area is part of the Albuquerque, New Mexico, Albuquerque–Santa Fe–Las Vegas, New Mexico, Las Vegas Albuquerque–Santa Fe–Las Vegas combined statistical area, combined statistical area, which had a population of 1,162,523 in 2020. Human settlement dates back thousands of years in the region, the placita was founded in 1610 as the capital of . It replace ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yangjiang
Yangjiang (, ), alternately romanized as Yeungkong, is a prefecture-level city in southwestern Guangdong Province in the People's Republic of China. It borders Maoming to the west, Yunfu to the north, Jiangmen to the east, and looks out to the South China Sea to the south. The local dialect is the Gaoyang dialect, a branch of Yue Chinese. During the 2020 census, its population was 2,602,959 inhabitants of whom 1,292,987 lived in the built-up (''or metro'') and largely urbanized area comprising Jiangcheng District and Yangdong County. History Under the Qing, made up part of the commandery of Zhaoqing. It was later split off as a separate prefecture in its own right. Administration The prefecture-level city of Yangjiang administers 4 county-level divisions, including 2 districts, 1 county-level city and 1 counties. Yangjiang is located, 2:30 hours from Guangzhou by bus. Notable areas include the Zhapo Beach and Hailing Island near Shapa Town. Economy and culture Yangjia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
