HOME
*



picture info

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 physical science laboratory programs that include 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 in 1789, granted these powers to the new Con ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Gaithersburg, Maryland
Gaithersburg ( ), officially the City of Gaithersburg, is a city in Montgomery County, Maryland, United States. At the time of the 2020 U.S. Census, Gaithersburg had a population of 69,657, making it the ninth-largest location in the state. Gaithersburg is located to the northwest of Washington, and is considered a suburb and a primary city within the Washington–Arlington–Alexandria, DC–VA–MD–WV Metropolitan Statistical Area. Gaithersburg was incorporated as a town in 1878 and as a city in 1968. Gaithersburg is located east and west of Interstate 270. The eastern section includes the historic area of the town. Landmarks and buildings from that time can still be seen in many places but especially in the historic central business district of Gaithersburg called "Olde Towne". The east side also includes Lakeforest Mall, City Hall, and the Montgomery County Fair grounds, and Bohrer Park (a well-known joint community recreation center and outdoor water park for kids and ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

John Quincy Adams
John Quincy Adams (; July 11, 1767 – February 23, 1848) was an American statesman, diplomat, lawyer, and diarist who served as the sixth president of the United States, from 1825 to 1829. He previously served as the eighth United States Secretary of State from 1817 to 1825. During his long diplomatic and political career, Adams also served as an ambassador, and as a member of the United States Congress representing Massachusetts in both chambers. He was the eldest son of John Adams, who served as the second president of the United States from 1797 to 1801, and First Lady Abigail Adams. Initially a Federalist like his father, he won election to the presidency as a member of the Democratic-Republican Party, and in the mid-1830s became affiliated with the Whig Party. Born in Braintree, Massachusetts, Adams spent much of his youth in Europe, where his father served as a diplomat. After returning to the United States, Adams established a successful legal practice in Bo ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

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 around 60). Crown glass is produced from alkali-lime silicates containing approximately 10% potassium oxide and is one of the earliest low dispersion glasses. As well as the specific material named ''crown glass'', there are other optical glasses with similar properties that are also called crown glasses. Generally, this is any glass with Abbe numbers in the range 50 to 85. For example, the borosilicate glass Schott BK7 (Schott designates it as 517642. The first three digits tell you its refractive index (1.517) and the last three tell you its Abbé number (64.2))The crown/flint distinction is so important to optical glass technology that many glass names, notably Schott glasses, incorporate it. A ''K'' in a Schott name indicates a crown glass (''Krone'' in German — Schott is a German company). The ''B'' ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fighting occurring throughout Europe, the Middle East, Africa, the Pacific, and parts of Asia. An estimated 9 million soldiers were killed in combat, plus another 23 million wounded, while 5 million civilians died as a result of military action, hunger, and disease. Millions more died in genocides within the Ottoman Empire and in the 1918 influenza pandemic, which was exacerbated by the movement of combatants during the war. Prior to 1914, the European great powers were divided between the Triple Entente (comprising France, Russia, and Britain) and the Triple Alliance (containing Germany, Austria-Hungary, and Italy). Tensions in the Balkans came to a head on 28 June 1914, following the assassination of Archduke Franz ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

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 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 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 remains in the liqu ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Herbert Hoover
Herbert Clark Hoover (August 10, 1874 – October 20, 1964) was an American politician who served as the 31st president of the United States from 1929 to 1933 and a member of the Republican Party (United States), Republican Party, holding office during the onset of the Great Depression in the United States. A self-made man who became rich as a mining engineer, Hoover led the Commission for Relief in Belgium, served as the director of the U.S. Food Administration, and served as the U.S. Secretary of Commerce. Hoover was born to a Quaker family in West Branch, Iowa, but he grew up in Oregon. He was one of the first graduates of the new Stanford University in 1895. He took a position with a London-based mining company working in Australia and China. He rapidly became a wealthy mining engineer. In 1914 at the outbreak of World War I, he organized and headed the Commission for Relief in Belgium, an international relief organization that provided food to occupied Belgium. When the ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Metrology
Metrology is the scientific study of measurement. It establishes a common understanding of 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 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 * The realisation of these units of measurement in practice * Traceabi ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Samuel Wesley Stratton
Samuel Wesley Stratton (July 18, 1861 – October 18, 1931) was an administrator in the American government, physicist, and educator. 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 after the summer vacation, Stratton was appointed head of the Department of Physics by regent Selim Hobart Peabody. As Physics head, Stratton organized a formal curriculum in electrical engineering, which was taught in the Physics Department until a separate department of electrical ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Theodore Roosevelt
Theodore Roosevelt Jr. ( ; October 27, 1858 – January 6, 1919), often referred to as Teddy or by his initials, T. R., was an American politician, statesman, soldier, conservationist, naturalist, historian, and writer who served as the 26th president of the United States from 1901 to 1909. He previously served as the 25th vice president under President William McKinley from March to September 1901 and as the 33rd governor of New York from 1899 to 1900. Assuming the presidency after McKinley's assassination, Roosevelt emerged as a leader of the Republican Party and became a driving force for anti-trust and Progressive policies. A sickly child with debilitating asthma, he overcame his health problems as he grew by embracing a strenuous lifestyle. Roosevelt integrated his exuberant personality and a vast range of interests and achievements into a "cowboy" persona defined by robust masculinity. He was home-schooled and began a lifelong naturalist avocation before attendin ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


picture info

Wheeled Chart Of National Bureau Of Standards Activities, 1915
A wheel is a circular component that is intended to rotate on an axle bearing. The wheel is one of the key components of the wheel and axle which is one of the six simple machines. Wheels, in conjunction with axles, allow heavy objects to be moved easily facilitating movement or transportation while supporting a load, or performing labor in machines. Wheels are also used for other purposes, such as a ship's wheel, steering wheel, potter's wheel, and flywheel. Common examples are found in transport applications. A wheel reduces friction by facilitating motion by rolling together with the use of axles. In order for wheels to rotate, a moment needs to be applied to the wheel about its axis, either by way of gravity or by the application of another external force or torque. Using the wheel, Sumerians invented a device that spins clay as a potter shapes it into the desired object. Terminology The English word ''wheel'' comes from the Old English word , from Proto-Germanic , fro ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  


James H
James is a common English language surname and given name: *James (name), the typically masculine first name James * James (surname), various people with the last name James James or James City may also refer to: People * King James (other), various kings named James * Saint James (other) * James (musician) * James, brother of Jesus Places Canada * James Bay, a large body of water * James, Ontario United Kingdom * James College, a college of the University of York United States * James, Georgia, an unincorporated community * James, Iowa, an unincorporated community * James City, North Carolina * James City County, Virginia ** James City (Virginia Company) ** James City Shire * James City, Pennsylvania * St. James City, Florida Arts, entertainment, and media * ''James'' (2005 film), a Bollywood film * ''James'' (2008 film), an Irish short film * ''James'' (2022 film), an Indian Kannada-language film * James the Red Engine, a character in ''Thomas the ...
[...More Info...]      
[...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]