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National Institute Of Standards And Technology
The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into Outline of physical science, physical science laboratory programs that include Nanotechnology, nanoscale science and technology, engineering, information technology, neutron research, material measurement, and physical measurement. From 1901 to 1988, the agency was named the National Bureau of Standards. History Background The Articles of Confederation, ratified by the colonies in 1781, provided: The United States in Congress assembled shall also have the sole and exclusive right and power of regulating the alloy and value of coin struck by their own authority, or by that of the respective states—fixing the standards of weights and measures throughout the United States. Article 1, section 8, of the Constitution of the United States, ratified i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gaithersburg, Maryland
Gaithersburg ( ) is a city in Montgomery County, Maryland, United States. At the time of the 2020 United States census, Gaithersburg had a population of 69,657, making it the third-largest incorporated city and the ninth-most populous community in the state. Gaithersburg is located to the northwest of Washington, D.C., and is considered a suburb and a primary city within the Washington metropolitan area. Gaithersburg was incorporated as a town in 1878 and as a city in 1968. The National Institute of Standards and Technology (NIST) is headquartered in Gaithersburg directly west of I-270. Other major employers in the city include IBM, Lockheed Martin Information Systems and Global Services business area headquarters, AstraZeneca. Gaithersburg is also the location of the garrison of the United States Army Reserve Legal Command. History Gaithersburg was settled in 1765 as a small agricultural settlement known as Log Town near the present day Summit Hall on Ralph Crabb's 1725 lan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Archives And Records Administration
The National Archives and Records Administration (NARA) is an independent agency of the United States government within the executive branch, charged with the preservation and documentation of government and historical records. It is also tasked with increasing public access to those documents that make up the National Archives. NARA is officially responsible for maintaining and publishing the legally authentic and authoritative copies of acts of Congress, presidential directives, and federal regulations. NARA also transmits votes of the Electoral College to Congress. It also examines Electoral College and constitutional amendment ratification documents for prima facie legal sufficiency and an authenticating signature. The National Archives, and its publicly exhibited Charters of Freedom, which include the original United States Declaration of Independence, Constitution of the United States, United States Bill of Rights, Emancipation Proclamation (starting in 2026), and m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harry Diamond (engineer)
Harry Diamond (12 February 1900 – 21 June 1948) was an American radio pioneer and inventor, and namesake for Diamond Ordnance Fuze Laboratories, which later became part of the Army Research Laboratory. Early life Diamond, the son of a Jewish tailor in Minsk, was born on February 12, 1900. In 1908 his family immigrated to the United States, and he grew up in Quincy, Massachusetts. Diamond enlisted in the United States Army on October 14, 1918 and was honorably discharged on December 9, 1918. He graduated with a degree in Electrical Engineering from Massachusetts Institute of Technology in 1922. Diamond worked for the General Electric company for 18 months. He completed his master's degree in Electrical Engineering in 1925 and worked as an Electrical Engineering instructor for 4 years at Lehigh University. Bureau of Standards He joined the National Bureau of Standards in 1927. Diamond headed up the research and development work of the Commerce Department’s newly organized Bur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crown Glass (optics)
Crown glass is a type of optical glass used in lenses and other optical components. It has relatively low refractive index (≈1.52) and low dispersion (with Abbe numbers between 50 and 85). Crown glass is produced from alkali-lime silicates containing approximately 10% potassium oxide and is one of the earliest low dispersion glasses. History The term originated from crown-glass windows, a method of window production that began in France during the Middle Ages. A molten blob of glass was attached to a pole and spun rapidly, flattening it out into a large disk from which windows were cut. The center, called the "crown" or "bullseye", was too thick for windows, but was often used to make lenses or deck prisms.''A Dictionary of the English Language - Volume 1, Part 1'' by Samuel Johnson, Robert Gordon Latham, Henry John Todd -- longmans, Green & Co. 1866 Page 314 Types The borosilicate glass Schott BK7 ( glass code 517642) is an extremely common crown glass, used in precisi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War I
World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting took place mainly in European theatre of World War I, Europe and the Middle Eastern theatre of World War I, Middle East, as well as in parts of African theatre of World War I, Africa and the Asian and Pacific theatre of World War I, Asia-Pacific, and in Europe was characterised by trench warfare; the widespread use of Artillery of World War I, artillery, machine guns, and Chemical weapons in World War I, chemical weapons (gas); and the introductions of Tanks in World War I, tanks and Aviation in World War I, aircraft. World War I was one of the List of wars by death toll, deadliest conflicts in history, resulting in an estimated World War I casualties, 10 million military dead and more than 20 million wounded, plus some 10 million civilian de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antifreeze
An antifreeze is an additive which lowers the freezing point of a water-based liquid. An antifreeze mixture is used to achieve freezing-point depression for cold environments. Common antifreezes also increase the boiling point of the liquid, allowing higher coolant temperature. However, all common antifreeze additives also have lower heat capacity, heat capacities than water, and do reduce water's ability to act as a coolant when added to it. Because water has good properties as a coolant, water plus antifreeze is used in internal combustion engines and other heat transfer applications, such as HVAC chillers and solar water heaters. The purpose of antifreeze is to prevent a rigid enclosure from bursting due to expansion when ice, water freezes. Commercially, both the ''additive'' (pure concentrate) and the ''mixture'' (diluted solution) are called antifreeze, depending on the context. Careful selection of an antifreeze can enable a wide temperature range in which the mixture remain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herbert Hoover
Herbert Clark Hoover (August 10, 1874 – October 20, 1964) was the 31st president of the United States, serving from 1929 to 1933. A wealthy mining engineer before his presidency, Hoover led the wartime Commission for Relief in Belgium and was the director of the U.S. Food Administration, followed by post-war relief of Europe. As a member of the Republican Party (United States), Republican Party, he served as the third United States secretary of commerce from 1921 to 1928 before being 1928 United States presidential election, elected president in 1928. His presidency was dominated by the Great Depression, and his policies and methods to combat it were seen as lackluster. Amid his unpopularity, he decisively lost reelection to Franklin D. Roosevelt in 1932 United States presidential election, 1932. Born to a Quaker family in West Branch, Iowa, Hoover grew up in Oregon. He was one of the first graduates of the new Stanford University in 1895. Hoover took a position with a Lond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metrology
Metrology is the scientific study of measurement. It establishes a common understanding of Unit of measurement, units, crucial in linking human activities. Modern metrology has its roots in the French Revolution's political motivation to standardise units in France when a length standard taken from a natural source was proposed. This led to the creation of the decimal-based metric system in 1795, establishing a set of standards for other types of measurements. Several other countries adopted the metric system between 1795 and 1875; to ensure conformity between the countries, the ''International Bureau of Weights and Measures, Bureau International des Poids et Mesures'' (BIPM) was established by the Metre Convention. This has evolved into the International System of Units (SI) as a result of a resolution at the 11th General Conference on Weights and Measures (CGPM) in 1960. Metrology is divided into three basic overlapping activities: * The definition of units of measurement * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metre
The metre (or meter in US spelling; symbol: m) is the base unit of length in the International System of Units (SI). Since 2019, the metre has been defined as the length of the path travelled by light in vacuum during a time interval of of a second, where the second is defined by a hyperfine transition frequency of caesium. The metre was originally defined in 1791 by the French National Assembly as one ten-millionth of the distance from the equator to the North Pole along a great circle, so the Earth's polar circumference is approximately . In 1799, the metre was redefined in terms of a prototype metre bar. The bar used was changed in 1889, and in 1960 the metre was redefined in terms of a certain number of wavelengths of a certain emission line of krypton-86. The current definition was adopted in 1983 and modified slightly in 2002 to clarify that the metre is a measure of proper length. From 1983 until 2019, the metre was formally defined as the length of the pat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kilogram
The kilogram (also spelled kilogramme) is the base unit of mass in the International System of Units (SI), equal to one thousand grams. It has the unit symbol kg. The word "kilogram" is formed from the combination of the metric prefix kilo- (meaning one thousand) and gram; it is colloquially shortened to "kilo" (plural "kilos"). The kilogram is an SI base unit, defined ultimately in terms of three defining constants of the SI, namely a specific transition frequency of the caesium-133 atom, the speed of light, and the Planck constant. A properly equipped metrology laboratory can calibrate a mass measurement instrument such as a Kibble balance as a primary standard for the kilogram mass. The kilogram was originally defined in 1795 during the French Revolution as the mass of one litre of water (originally at 0 °C, later changed to the temperature of its maximum density, approximately 4 °C). The current definition of a kilogram agrees with this original defini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Samuel Wesley Stratton
Samuel Wesley Stratton (July 18, 1861 – October 18, 1931) was an administrator in the American government, physicist, and educator. A physicist by training, Stratton proposed the U.S. Bureau of Standards and was appointed its first director by President Theodore Roosevelt. In 1923, he moved to Boston to become the eighth president of the Massachusetts Institute of Technology, a position he held for seven years. Life and work Stratton was born on farm in Litchfield, Illinois on July 18, 1861. In his youth he kept farm machinery in repair and worked as a mechanic and carpenter. He worked his way through Illinois Industrial University at Urbana (later the University of Illinois), receiving his bachelor of science degree in mechanical engineering in 1884. He became an instructor in mathematics and physics following his graduation, and in 1889, when Physics department head Theodore B. Comstock, Professor of Mining Engineering and Physics, inexplicably failed to return to campus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
