Unit of measurement

A unit of measurement is a definite magnitude of a quantity and adopted by convention or by law, used as a standard for measurement of the same kind of quantity. Any other quantity of that kind can be expressed as a multiple of the unit of measurement. For example, a length is a physical quantity; the metre is a unit of length. When we say 10 metres, we mean 10 times the definite predetermined length called "metre". Measurement is a process of determining how large or small a physical quantity is as compared to a basic reference quantity of the same kind; the definition and practical use of units of measurement have played a crucial role in human endeavour from early ages up to the present. A multitude of systems of units used to be common. Now there is a global standard, the International System of Units, the modern form of the metric system. In trade and measures is a subject of governmental regulation, to ensure fairness and transparency; the International Bureau of Weights and Measures is tasked with ensuring worldwide uniformity of measurements and their traceability to the International System of Units.

Metrology internationally accepted units of measurement. In physics and metrology, units are standards for measurement of physical quantities that need clear definitions to be useful. Reproducibility of experimental results is central to the scientific method. A standard system of units facilitates this. Scientific systems of units are a refinement of the concept of weights and measures developed for commercial purposes. Science and engineering use larger and smaller units of measurement than those used in everyday life; the judicious selection of the units of measurement can aid researchers in problem solving. In the social sciences, there are no standard units of measurement and the theory and practice of measurement is studied in psychometrics and the theory of conjoint measurement. A unit of measurement is a standardised quantity of a physical property, used as a factor to express occurring quantities of that property. Units of measurement were among the earliest tools invented by humans. Primitive societies needed rudimentary measures for many tasks: constructing dwellings of an appropriate size and shape, fashioning clothing, or bartering food or raw materials.

The earliest known uniform systems of measurement seem to have all been created sometime in the 4th and 3rd millennia BC among the ancient peoples of Mesopotamia and the Indus Valley, also Elam in Persia as well. Weights and measures are mentioned in the Bible, it is a commandment to have fair measures. In the Magna Carta of 1215 with the seal of King John, put before him by the Barons of England, King John agreed in Clause 35 "There shall be one measure of wine throughout our whole realm, one measure of ale and one measure of corn—namely, the London quart; as of the 21st Century, multiple unit systems are used all over the world such as the United States Customary System, the British Customary System, the International System. However, the United States is the only industrialized country that has not yet converted to the Metric System; the systematic effort to develop a universally acceptable system of units dates back to 1790 when the French National Assembly charged the French Academy of Sciences to come up such a unit system.

This system was the precursor to the metric system, developed in France but did not take on universal acceptance until 1875 when The Metric Convention Treaty was signed by 17 nations. After this treaty was signed, a General Conference of Weights and Measures was established; the CGPM produced the current SI system, adopted in 1954 at the 10th conference of weights and measures. The United States is a dual-system society which uses both the SI system and the US Customary system; the use of a single unit of measurement for some quantity has obvious drawbacks. For example, it is impractical to use the same unit for the distance between two cities and the length of a needle, thus they would develop independently. One way to make large numbers or small fractions easier to read, is to use unit prefixes. At some point in time though, the need to relate the two units might arise, the need to choose one unit as defining the other or vice versa. For example, an inch could be defined in terms of a barleycorn.

A system of measurement is a collection of units of measurement and rules relating them to each other. As science progressed, a need arose to relate the measurement systems of different quantities, like length and weight and volume; the effort of attempting to relate different traditional systems between each other exposed many inconsistencies, brought about the development of new units and systems. The system of units varies from country to country and some of the different system of units are CGS system of units, FPS system of units, MKS system of units and SI system of units. Among the different system of units using in the world, the most used and internationally accepted one is the International System of Units, or SI system of units. In this SI units system, there are seven SI base units and three supplementary units; the base SI units are metre, second, Ampere and the mole and the three supplementary SI units are radian and becquerel. All other SI units can be derived from these base units.

Systems of measurement in modern use include the metric sy

Kari Blackburn

Kari Boto was a BBC reporter and senior executive who specialised in Africa. Blackburn was born in Somerset on 30 March 1954 to Irish educationist Robert Blackburn and Esther Archer, she took her A-levels at United World College of the Atlantic and studied in the Faculty of Social and Political Sciences at Churchill College and graduated with First Class Honours. Afterwards, she travelled to Africa to teach in a primary school in Tanzania, returning to Europe in 1977. Blackburn met her future husband, in London. Boto had fled Uganda to escape the regime of Idi Amin, who came to power through a coup d'état in 1971. Blackburn and Boto were married in 1981, had two children: a daughter and a son, they adopted a nephew of Boto's as their third child. Blackburn joined the BBC in 1977 as a news trainee, continued to work for the broadcasting corporation until her death. In 1992, she became editor of the BBC Marshall Plan of the Mind Trust, a "multimedia education project" for the former Soviet republics.

From 1996 to 1999, she headed the BBC Great Lakes Service. She became head of BBC World Service Africa in 1999, remained in this post until 2003, when she became regional executive director of BBC World Service for Africa and the Middle East. Broadcast in English and seven other languages. In October 2006, she became director of international operations at the BBC World Service Trust, an "independently-funded development charity of the BBC". Blackburn died on 27 June 2007, her death came three days before the expiration of her BBC contract and the week of the 25th anniversary celebration for the BBC Swahili Service that she had not been invited to attend, despite her many years of past involvement. Witnesses reported seeing her "sitting with her head in her hands near the beach" shortly before her death. Blackburn was reported missing after her keys were found on the beach. Notes addressed to her husband and children were found in Blackburn's car, her body was recovered and transported by a RAF helicopter to Ipswich Hospital, but she could not be resuscitated.

John Ssebaana Kizito, president of Uganda's Democratic Party and former mayor of Kampala, paid tribute to Blackburn in early July, writing: "The death of Kari Blackburn comes as a great shock to me. It is as unexpected as it is devastating."An inquest, held on 16 May 2008, ruled her death to have been a suicide. According to Boto, a Ugandan consultant gynaecologist at Ipswich Hospital, Blackburn suffered from "mental and physical illness" after assuming her position at BBC World Service Trust and felt "isolated and under-supported". Boto blamed the BBC for his wife's death, claiming that she "was crying for help but nobody at the BBC listened to her problems"; the BBC released a statement in response to the coroner's judgment, describing Blackburn as "a popular leader, with great humanity and compassion" who "was devoted to the BBC". On news of her suicide, hundreds of people working for the BBC World Service and BBC Newsgathering signed a petition demanding an independent inquiry into the circumstances leading up to her death and the role that the work environment may have played in her depression.

List of drowning victims Kari Blackburn – BBC Press Office

E. Gail de Planque

Eileen Gail de Planque was an American nuclear physicist. An expert on environmental radiation measurements, she was the first woman and first health physicist to become a Commissioner at the US government's Nuclear Regulatory Commission, her technical areas of expertise included environmental radiation, nuclear facilities monitoring, personnel dosimetry, radiation shielding, radiation transport, solid state dosimetry. Born in New Jersey and raised in Maryland, Planque earned her bachelor's degree from Immaculata College, Master's degree from the Newark College of Engineering, PhD from New York University. From 1967 until 1982, she worked as a physicist for the Atomic Energy Commission, she joined the Environmental Measurements Laboratory, US Department of Energy as its deputy director in 1982, was promoted to director five years later. From 1991-95, she was a member of the NRC. In 1997, Planque chaired a planning committee, Celebration of Women in Engineering, which developed conferences that encouraged women to choose careers in engineering and included the development of the website EngineerGirl.

A Fellow of the American Nuclear Society and the American Association for the Advancement of Science, Planque was a member of the National Academy of Engineering, Association of Women in Science, the National Council on Radiation Protection and Measurements. She served as president of the ANS, Health Physics Society. In the late 1970s, Planque was a US expert delegate to the international committee for Development of an International Standard on Thermoluminescence Dosimetry. Planque was married to Frank Burke, she lived in New York City, Potomac, Maryland. Planque died in 2010. 1990, Women of Achievement in Energy award 1991, Outstanding Woman Scientist of the Year award 2003, Henry DeWolf Smyth Award for Nuclear Statesmanship 2004, Women in Technology International Hall of Fame inductees