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International Commission On Radiation Units And Measurements
The International Commission on Radiation Units and Measurements (ICRU) is a standardization body set up in 1925 by the International Congress of Radiology, originally as the X-Ray Unit Committee until 1950. Its objective "is to develop concepts, definitions and recommendations for the use of quantities and their units for ionizing radiation and its interaction with matter, in particular with respect to the biological effects induced by radiation". The ICRU is a sister organisation to the International Commission on Radiological Protection (ICRP). In general terms the ICRU defines the units, and the ICRP recommends how they are used for radiation protection. Development During the first two decades of its existence, its formal meetings were held during the International Congress of Radiology, but from 1950 onwards, when its mandate was extended, it has met annually. Until 1953, the president of the ICRU was a national of the country that was hosting the ICR, but in that year it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Quantity
A physical quantity is a physical property of a material or system that can be quantified by measurement. A physical quantity can be expressed as a ''value'', which is the algebraic multiplication of a ' Numerical value ' and a ' Unit '. For example, the physical quantity of mass can be quantified as '32.3 kg ', where '32.3' is the numerical value and 'kg' is the Unit. A physical quantity possesses at least two characteristics in common. # Numerical magnitude. # Units Symbols and nomenclature International recommendations for the use of symbols for quantities are set out in ISO/IEC 80000, the IUPAP red book and the IUPAC green book. For example, the recommended symbol for the physical quantity ''mass'' is ''m'', and the recommended symbol for the quantity ''electric charge'' is ''Q''. Subscripts and indices Subscripts are used for two reasons, to simply attach a name to the quantity or associate it with another quantity, or index a specific component (e.g., row or co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dose Quantities And Units
Dose or Dosage may refer to: Music * ''Dose'' (Gov't Mule album), 1998 * ''Dose'' (Latin Playboys album) * ''Dosage'' (album), by the band Collective Soul * "Dose" (song), a 2018 song by Ciara * "Dose", song by Filter from the album '' Short Bus'' Science * Dose (biochemistry), a measured quantity of a medicine, nutrient, or pathogen which is delivered as a unit. * Dosage form, a mixture of active and inactive components used to administer a medication * Dosing, feeding chemicals or medicines when used in small quantities * Effective dose (pharmacology), a dose or concentration of a drug that produces a biological response *Absorbed dose, a measure of energy deposited in matter from ionizing radiation *Equivalent dose, a measure of cancer/heritable health risk in tissue from ionizing radiation *Effective dose (radiation), a measure of cancer/heritable health risk to the whole body from ionizing radiation *Median lethal dose, a measure of the lethal dose of a toxin, radiati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standards Organizations In Sweden
Standard may refer to: Symbols * Colours, standards and guidons, kinds of military signs * Standard (emblem), a type of a large symbol or emblem used for identification Norms, conventions or requirements * Standard (metrology), an object that bears a defined relationship to a unit of measure used for calibration of measuring devices * Standard (timber unit), an obsolete measure of timber used in trade * Breed standard (also called bench standard), in animal fancy and animal husbandry * BioCompute Standard, a standard for next generation sequencing * ''De facto'' standard, product or system with market dominance * Gold standard, a monetary system based on gold; also used metaphorically for the best of several options, against which the others are measured * Internet Standard, a specification ratified as an open standard by the Internet Engineering Task Force * Learning standards, standards applied to education content * Standard displacement, a naval term describing the w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiology Organizations
Radiology ( ) is the medical discipline that uses medical imaging to diagnose diseases and guide their treatment, within the bodies of humans and other animals. It began with radiography (which is why its name has a root referring to radiation), but today it includes all imaging modalities, including those that use no electromagnetic radiation (such as ultrasonography and magnetic resonance imaging), as well as others that do, such as computed tomography (CT), fluoroscopy, and nuclear medicine including positron emission tomography (PET). Interventional radiology is the performance of usually minimally invasive medical procedures with the guidance of imaging technologies such as those mentioned above. The modern practice of radiology involves several different healthcare professions working as a team. The radiologist is a medical doctor who has completed the appropriate post-graduate training and interprets medical images, communicates these findings to other physicians ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sievert
The sievert (symbol: SvNot be confused with the sverdrup or the svedberg, two non-SI units that sometimes use the same symbol.) is a unit in the International System of Units (SI) intended to represent the stochastic health risk of ionizing radiation, which is defined as the probability of causing radiation-induced cancer and genetic damage. The sievert is important in dosimetry and radiation protection. It is named after Rolf Maximilian Sievert, a Swedish medical physicist renowned for work on radiation dose measurement and research into the biological effects of radiation. The sievert is used for radiation dose quantities such as equivalent dose and effective dose, which represent the risk of external radiation from sources outside the body, and committed dose, which represents the risk of internal irradiation due to inhaled or ingested radioactive substances. According to the International Commission on Radiological Protection (ICRP) one sievert results in a 5.5% prob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiation Protection
Radiation protection, also known as radiological protection, is defined by the International Atomic Energy Agency (IAEA) as "The protection of people from harmful effects of exposure to ionizing radiation, and the means for achieving this". Exposure can be from a source of radiation external to the human body or due to internal irradiation caused by the ingestion of radioactive contamination. Ionizing radiation is widely used in industry and medicine, and can present a significant health hazard by causing microscopic damage to living tissue. There are two main categories of ionizing radiation health effects. At high exposures, it can cause "tissue" effects, also called "deterministic" effects due to the certainty of them happening, conventionally indicated by the unit gray and resulting in acute radiation syndrome. For low level exposures there can be statistically elevated risks of radiation-induced cancer, called " stochastic effects" due to the uncertainty of them happening, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Radiation Protection Association
The International Radiation Protection Association (IRPA) is an independent non-profit association of national and regional radiation protection societies, and its mission is to advance radiation protection throughout the world. It is the international professional association for radiation protection.) IRPA is recognized by the IAEA as a Non Governmental Organization (NGO) and is an observer on the IAEA Radiation Safety Standards Committee (RASSC). IRPA was formed on June 19, 1965, at a meeting in Los Angeles; stimulated by the desire of radiation protection professionals to have a world-wide body. Membership includes 50 Associate Societies covering 65 countries, totaling approximately 18,000 individual members. Structure The General Assembly, made up of representatives from the Associate Societies, is the representative body of the Association. It delegates authority to the Executive Council for the efficient administration of the affairs of the Association. Specific duti ... [...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 measurem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charitable Organization
A charitable organization or charity is an organization whose primary objectives are philanthropy and social well-being (e.g. educational, religious or other activities serving the public interest or common good). The legal definition of a charitable organization (and of charity) varies between countries and in some instances regions of the country. The regulation, the tax treatment, and the way in which charity law affects charitable organizations also vary. Charitable organizations may not use any of their funds to profit individual persons or entities. (However, some charitable organizations have come under scrutiny for spending a disproportionate amount of their income to pay the salaries of their leadership). Financial figures (e.g. tax refund, revenue from fundraising, revenue from sale of goods and services or revenue from investment) are indicators to assess the financial sustainability of a charity, especially to charity evaluators. This information can impact a c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Units Of Measurement Directives
As of 2009, the European Union had issued two units of measurement directives: In 1971 it issued Directive 71/354/EEC which required EU member states to standardise on the International System of Units (SI) rather than use a variety of CGS and MKS units then in use. The second, which replaced the first, was Directive 80/181/EEC made in 1979 and amended in 1984, 1989, 2000 and 2009. It issued a number of derogations to the United Kingdom and Ireland based on the former directive. Directive 71/354/EEC When the first units of measurement directive was issued, the six members of the EEC had been using the metric system for a hundred years or more. During that time the metric system had undergone a number of changes, particularly in science and engineering. Some industries were based on the CGS variant of the metric system and other on the MKS variant. In 1960, the CGPM published the International System of Units (SI), a coherent version of the metric system based on the MKS va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Union
The European Union (EU) is a supranational political and economic union of member states that are located primarily in Europe. The union has a total area of and an estimated total population of about 447million. The EU has often been described as a ''sui generis'' political entity (without precedent or comparison) combining the characteristics of both a federation and a confederation. Containing 5.8per cent of the world population in 2020, the EU generated a nominal gross domestic product (GDP) of around trillion in 2021, constituting approximately 18per cent of global nominal GDP. Additionally, all EU states but Bulgaria have a very high Human Development Index according to the United Nations Development Programme. Its cornerstone, the Customs Union, paved the way to establishing an internal single market based on standardised legal framework and legislation that applies in all member states in those matters, and only those matters, where the states have agreed to ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rem (unit)
The roentgen equivalent man (rem) is a CGS unit of equivalent dose, effective dose, and committed dose, which are dose measures used to estimate potential health effects of low levels of ionizing radiation on the human body. Quantities measured in rem are designed to represent the stochastic biological risk of ionizing radiation, which is primarily radiation-induced cancer. These quantities are derived from absorbed dose, which in the CGS system has the unit rad. There is no universally applicable conversion constant from rad to rem; the conversion depends on relative biological effectiveness (RBE). The rem has been defined since 1976 as equal to 0.01 sievert, which is the more commonly used SI unit outside the United States. Earlier definitions going back to 1945 were derived from the roentgen unit, which was named after Wilhelm Röntgen, a German scientist who discovered X-rays. The unit name is misleading, since 1 roentgen actually deposits about 0.96 rem in soft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
