1.
Sediment
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For sediment in beverages, see dregs. For example, sand and silt can be carried in suspension in water and on reaching the sea be deposited by sedimentation. Sediments are most often transported by water, but also wind, beach sands and river channel deposits are examples of fluvial transport and deposition, though sediment also often settles out of slow-moving or standing water in lakes and oceans. Desert sand dunes and loess are examples of transport and deposition. Glacial moraine deposits and till are ice-transported sediments, sediment can be classified based on its grain size and/or its composition. Sediment size is measured on a log base 2 scale, called the Phi scale, composition of sediment can be measured in terms of, parent rock lithology mineral composition chemical make-up. This leads to an ambiguity in which clay can be used as both a size-range and a composition, sediment is transported based on the strength of the flow that carries it and its own size, volume, density, and shape. Stronger flows will increase the lift and drag on the particle, causing it to rise, rivers and streams carry sediment in their flows. This sediment can be in a variety of locations within the flow and these relationships are shown in the following table for the Rouse number, which is a ratio of sediment fall velocity to upwards velocity. If the upwards velocity is less than the settling velocity, but still high enough for the sediment to move, it will move along the bed as bed load by rolling, sliding. If the upwards velocity is higher than the velocity, the sediment will be transported high in the flow as wash load. As there are generally a range of different particle sizes in the flow, sediment motion can create self-organized structures such as ripples, dunes, antidunes on the river or stream bed. These bedforms are often preserved in rocks and can be used to estimate the direction. Overland flow can erode soil particles and transport them downslope, the erosion associated with overland flow may occur through different methods depending on meteorological and flow conditions. If the initial impact of rain droplets dislodges soil, the phenomenon is called rainsplash erosion, if overland flow is directly responsible for sediment entrainment but does not form gullies, it is called sheet erosion. If the flow and the substrate permit channelization, gullies may form, glaciers carry a wide range of sediment sizes, and deposit it in moraines. The overall balance between sediment in transport and sediment being deposited on the bed is given by the Exner equation and this expression states that the rate of increase in bed elevation due to deposition is proportional to the amount of sediment that falls out of the flow. This can be localized, and simply due to obstacles, examples are scour holes behind boulders, where flow accelerates
2.
Bay
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A bay is a recessed, coastal body of water that directly connects to a larger main body of water, such as an ocean, lake, or another bay. A large bay may be called a gulf, sea, sound, a cove is a type of smaller bay with a circular inlet and narrow entrance. A fjord is a particularly steep bay shaped by glacial activity, bays can be the estuary of a river, such as the Chesapeake Bay, an estuary of the Susquehanna River, which is the largest bay in North America. Bays may also be nested within each other, for example, some large bays, such as the Bay of Bengal and the Hudson Bay, have varied marine geology. The land surrounding a bay often reduces the strength of winds, bays were significant in the history of human settlement because they provided a safe place for fishing. Later they were important in the development of sea trade as the safe anchorage they provide encouraged their selection as ports, there are various ways from which bays can be created. The largest bays have developed as a result of plate tectonics, as the super-continent Pangaea broke up along curved and indented fault lines, the continents moved apart and the worlds largest bays formed. These include the Gulf of Guinea, Gulf of Mexico and the Bay of Bengal, another way bays form is via glacial and river erosion. A bay formed by a glacier is a fjord, rias are created by rivers and are characterised by more gradual slopes. Currents can make waves more constant, and soft rocks speed erosion, hard rock eroded less quickly, leaving headlands. The Gulf of California is an example of a bay created by plate tectonics as Baja California peninsula moves away from the Mexican mainland, Bay platform Great capes Headlands and bays
3.
Pebble
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A pebble is a clast of rock with a particle size of 2 to 64 millimetres based on the Krumbein phi scale of sedimentology. Pebbles are generally considered larger than granules and smaller than cobbles, a rock made predominantly of pebbles is termed a conglomerate. Pebble tools are among the earliest known man-made artifacts, dating from the Palaeolithic period of human history, a beach composed chiefly of surface pebbles is commonly termed a shingle beach. This type of beach has armoring characteristics with respect to wave erosion, as well as ecological niches that provide habitat for animals and plants. Inshore banks of shingle exist in locations, such as the entrance to the River Ore. Pebbles come in colors and textures and can have streaks, known as veins. Pebbles are mostly smooth but, dependent on how frequently they come in contact with the sea, pebbles left above the high water mark may have growths of organisms such as lichen on them, signifying the lack of contact with seawater. Pebbles are found in two locations – on the beaches of various oceans and seas, and inland where ancient seas used to cover the land, when then the seas retreated, the rocks became landlocked. They can also be found in lakes and ponds, pebbles can also form in rivers, and travel into estuaries where the smoothing continues in the sea. Beach pebbles and river pebbles are distinct in their geological formation, beach pebbles form gradually over time as the ocean water washes over loose rock particles. The result is a smooth, rounded appearance, the typical size range is from 2 mm to 50 mm. The colors range from translucent white to black, and include shades of yellow, brown, red and green. Some of the more plentiful pebble beaches are found along the coast of the Pacific Ocean, beginning in the United States and extending down to the tip of South America in Argentina. Other pebble beaches are found in northern Europe, along the coast of the U. K. and Ireland, on the shores of Australia, inland pebbles are usually found along the shores of large rivers and lakes. These pebbles form as the water washes over rock particles on the bottom. The smoothness and color of river pebbles depends on several factors, such as the composition of the soil of the banks, the chemical characteristics of the water. Because river current is gentler than the waves, river pebbles are usually not as smooth as beach pebbles. The most common colors of rock are black, grey, green, brown
4.
Node (physics)
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A node is a point along a standing wave where the wave has minimum amplitude. For instance, in a guitar string, the ends of the string are nodes. By changing the position of the end node through frets, the guitarist changes the length of the vibrating string. The opposite of a node is an anti-node, a point where the amplitude of the wave is a maximum. These occur midway between the nodes, standing waves result when two sinusoidal wave trains of the same frequency are moving in opposite directions in the same space and interfere with each other. In a standing wave the nodes are a series of locations at equally spaced intervals where the amplitude is zero. At these points the two waves add with opposite phase and cancel each other out and they occur at intervals of half a wavelength. Midway between each pair of nodes are locations where the amplitude is maximum, at these points the two waves add with the same phase and reinforce each other. In cases where the two opposite wave trains are not the amplitude, they do not cancel perfectly, so the amplitude of the standing wave at the nodes is not zero. This occurs when the reflection at the boundary is imperfect and this is indicated by a finite standing wave ratio, the ratio of the amplitude of the wave at the antinode to the amplitude at the node. These can be visible by sprinkling sand on the surface. In transmission lines a voltage node is a current antinode, in this type the derivative of the waves amplitude is forced to zero at the boundary. So there is a maximum at the boundary, the first node occurs a quarter wavelength from the end. A sound wave consists of alternating cycles of compression and expansion of the wave medium, during compression, the molecules of the medium are forced together, resulting in the increased pressure and density. During expansion the molecules are forced apart, resulting in the decreased pressure, the number of nodes in a specified length is directly proportional to the frequency of the wave. Occasionally on a guitar, violin, or other stringed instrument, when the finger is placed on top of the string at a certain point, but does not push the string all the way down to the fretboard, a third node is created and a harmonic is sounded. During normal play when the frets are used, the harmonics are always present, with the artificial node method, the overtone is louder and the fundamental tone is quieter. If the finger is placed at the midpoint of the string, the first overtone is heard, when two additional nodes divide the string into thirds, this creates an octave and a perfect fifth
5.
Undertone series
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In music, the undertone series or subharmonic series is a sequence of notes that results from inverting the intervals of the overtone series. While overtones naturally occur with the production of music on instruments. The overtone series being a series, the undertone series is based on arithmetic division. The hybrid term subharmonic is used in music and dynamics in a few different ways, in its pure sense, the term subharmonic refers strictly to any member of the subharmonic series. When the subharmonic series is used to refer to frequency relationships, the complex tones of acoustic instruments do not produce partials that resemble the subharmonic series. However, such tones can be produced artificially with audio software, subharmonics can be contrasted with harmonics. While harmonics can. occur in any system, there are. only fairly restricted conditions that will lead to the nonlinear phenomenon known as subharmonic generation. One way to define subharmonics is that they are. integral submultiples of the fundamental frequency, the human voice can also be forced into a similar driven resonance, also called “undertone singing”, to extend the range of the voice below what is normally available. The overtone series can be produced physically in two ways—either by overblowing a wind instrument, or by dividing a monochord string. If a monochord string is lightly damped at the point, then at 1/3, then 1/4, 1/5, etc. then the string will produce the overtone series. If instead, the length of the string is doubled in the opposite ratios, similarly, on a wind instrument, if the holes are equally spaced, each successive hole covered will produce the next note in the undertone series. In addition, José Sotorrio showed that undertones could be made through the use of an oscillator such as a tuning fork. If that oscillator is gently forced to vibrate against a sheet of paper it will make contact at various audible modes of vibration. The tritare, a guitar with Y shaped strings, cause subharmonics too and this can also be achieved by the extended technique of crossing two strings as some experimental jazz guitarists have developed. Also third bridge preparations on guitars cause timbres consisting of sets of high pitched overtones combined with a resonant tone of the unplugged part of the string. Subharmonics can be produced by signal amplification through loudspeakers, Subharmonic frequencies are frequencies below the fundamental frequency of an oscillator in a ratio of 1/n, with n a positive integer number. For example, if the frequency of an oscillator is 440 Hz, sub-harmonics include 220 Hz. Thus, they are an image of the harmonic series
6.
Computer simulation
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Computer simulations reproduce the behavior of a system using a model. Simulation of a system is represented as the running of the systems model and it can be used to explore and gain new insights into new technology and to estimate the performance of systems too complex for analytical solutions. The scale of events being simulated by computer simulations has far exceeded anything possible using traditional paper-and-pencil mathematical modeling, other examples include a 1-billion-atom model of material deformation, a 2. Because of the computational cost of simulation, computer experiments are used to perform such as uncertainty quantification. A computer model is the algorithms and equations used to capture the behavior of the system being modeled, by contrast, computer simulation is the actual running of the program that contains these equations or algorithms. Simulation, therefore, is the process of running a model, thus one would not build a simulation, instead, one would build a model, and then either run the model or equivalently run a simulation. It was a simulation of 12 hard spheres using a Monte Carlo algorithm, Computer simulation is often used as an adjunct to, or substitute for, modeling systems for which simple closed form analytic solutions are not possible. The external data requirements of simulations and models vary widely, for some, the input might be just a few numbers, while others might require terabytes of information. Because of this variety, and because diverse simulation systems have common elements. Systems that accept data from external sources must be careful in knowing what they are receiving. While it is easy for computers to read in values from text or binary files, often they are expressed as error bars, a minimum and maximum deviation from the value range within which the true value lie. Even small errors in the data can accumulate into substantial error later in the simulation. While all computer analysis is subject to the GIGO restriction, this is true of digital simulation. Indeed, observation of this inherent, cumulative error in digital systems was the main catalyst for the development of chaos theory, another way of categorizing models is to look at the underlying data structures. For time-stepped simulations, there are two classes, Simulations which store their data in regular grids and require only next-neighbor access are called stencil codes. Many CFD applications belong to this category, if the underlying graph is not a regular grid, the model may belong to the meshfree method class. Equations define the relationships between elements of the system and attempt to find a state in which the system is in equilibrium. Such models are used in simulating physical systems, as a simpler modeling case before dynamic simulation is attempted
7.
Centre national de la recherche scientifique
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The French National Center for Scientific Research is the largest governmental research organisation in France and the largest fundamental science agency in Europe. It employs 32,000 permanent employees and 6,000 temporary workers, the National Committee for Scientific Research, which is in charge of the recruitment and evaluation of researchers, is divided into 47 sections. Research groups are affiliated with one institute and an optional secondary institute. For administrative purposes, the CNRS is divided into 18 regional divisions, CNRS research units are called laboratoires informally and unités de recherche in administrative parlance. They are either operated solely by CNRS or UPR) or in association with other institutions, each research unit has a unique numeric code attached and is headed by a director. A research unit may be subdivided into research groups, CNRS also has support units, which, analogously to the research units, are called unités propres de service or unités mixtes de service. A UPS or UMS may for instance supply administrative, computing, library, the headquarters of CNRS are at the Campus Gérard Mégie in the 16th arrondissement of Paris. Researchers who are permanent employees of the CNRS are classified in two categories, in order of seniority, Research scientists, 2nd class, 1st class, Research directors, 2nd class, 1st class, exceptional class. In principle, research directors tend to research groups. Employees for support activities include research engineers, studies engineers, assistant engineers, contrary to what the name would seem to imply, these can have administrative duties. All permanent support employees are recruited through annual nationwide competitive campaigns, following a 1983 reform, the candidates selected have the status of civil servants and are part of the public service. The CNRS is represented with administrative offices in Brussels, Beijing, Tokyo, Singapore, Washington, bonn, Moscow, Tunis, Johannesburg, Santiago de Chile, Israel, and New Delhi. The CNRS was created on 19 October 1939 by decree of President Albert Lebrun, since 1954, the centre has annually awarded gold, silver, and bronze medals to French scientists and junior researchers. The performance of the CNRS has been questioned, with calls for wide-ranging reforms, in particular, the effectiveness of the recruitment, compensation, career management, and evaluation procedures have been under scrutiny. Governmental projects include the transformation of the CNRS into an organ allocating support to projects on an ad hoc basis. Another controversial plan advanced by the government involves breaking up the CNRS into six separate institutes, alain Fuchs was appointed president on 20 January 2010. His position combines the positions of president and director general
8.
France
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France, officially the French Republic, is a country with territory in western Europe and several overseas regions and territories. The European, or metropolitan, area of France extends from the Mediterranean Sea to the English Channel and the North Sea, Overseas France include French Guiana on the South American continent and several island territories in the Atlantic, Pacific and Indian oceans. France spans 643,801 square kilometres and had a population of almost 67 million people as of January 2017. It is a unitary republic with the capital in Paris. Other major urban centres include Marseille, Lyon, Lille, Nice, Toulouse, during the Iron Age, what is now metropolitan France was inhabited by the Gauls, a Celtic people. The area was annexed in 51 BC by Rome, which held Gaul until 486, France emerged as a major European power in the Late Middle Ages, with its victory in the Hundred Years War strengthening state-building and political centralisation. During the Renaissance, French culture flourished and a colonial empire was established. The 16th century was dominated by civil wars between Catholics and Protestants. France became Europes dominant cultural, political, and military power under Louis XIV, in the 19th century Napoleon took power and established the First French Empire, whose subsequent Napoleonic Wars shaped the course of continental Europe. Following the collapse of the Empire, France endured a succession of governments culminating with the establishment of the French Third Republic in 1870. Following liberation in 1944, a Fourth Republic was established and later dissolved in the course of the Algerian War, the Fifth Republic, led by Charles de Gaulle, was formed in 1958 and remains to this day. Algeria and nearly all the colonies became independent in the 1960s with minimal controversy and typically retained close economic. France has long been a centre of art, science. It hosts Europes fourth-largest number of cultural UNESCO World Heritage Sites and receives around 83 million foreign tourists annually, France is a developed country with the worlds sixth-largest economy by nominal GDP and ninth-largest by purchasing power parity. In terms of household wealth, it ranks fourth in the world. France performs well in international rankings of education, health care, life expectancy, France remains a great power in the world, being one of the five permanent members of the United Nations Security Council with the power to veto and an official nuclear-weapon state. It is a member state of the European Union and the Eurozone. It is also a member of the Group of 7, North Atlantic Treaty Organization, Organisation for Economic Co-operation and Development, the World Trade Organization, originally applied to the whole Frankish Empire, the name France comes from the Latin Francia, or country of the Franks
9.
United States Navy
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The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U. S. Navy is the largest, most capable navy in the world, the U. S. Navy has the worlds largest aircraft carrier fleet, with ten in service, two in the reserve fleet, and three new carriers under construction. The service has 323,792 personnel on duty and 108,515 in the Navy Reserve. It has 274 deployable combat vessels and more than 3,700 operational aircraft as of October 2016, the U. S. Navy traces its origins to the Continental Navy, which was established during the American Revolutionary War and was effectively disbanded as a separate entity shortly thereafter. It played a role in the American Civil War by blockading the Confederacy. It played the role in the World War II defeat of Imperial Japan. The 21st century U. S. Navy maintains a global presence, deploying in strength in such areas as the Western Pacific, the Mediterranean. The Navy is administratively managed by the Department of the Navy, the Department of the Navy is itself a division of the Department of Defense, which is headed by the Secretary of Defense. The Chief of Naval Operations is an admiral and the senior naval officer of the Department of the Navy. The CNO may not be the highest ranking officer in the armed forces if the Chairman or the Vice Chairman of the Joint Chiefs of Staff. The mission of the Navy is to maintain, train and equip combat-ready Naval forces capable of winning wars, deterring aggression, the United States Navy is a seaborne branch of the military of the United States. The Navys three primary areas of responsibility, The preparation of naval forces necessary for the prosecution of war. The development of aircraft, weapons, tactics, technique, organization, U. S. Navy training manuals state that the mission of the U. S. Armed Forces is to prepare and conduct prompt and sustained combat operations in support of the national interest, as part of that establishment, the U. S. Navys functions comprise sea control, power projection and nuclear deterrence, in addition to sealift duties. It follows then as certain as that night succeeds the day, that without a decisive naval force we can do nothing definitive, the Navy was rooted in the colonial seafaring tradition, which produced a large community of sailors, captains, and shipbuilders. In the early stages of the American Revolutionary War, Massachusetts had its own Massachusetts Naval Militia, the establishment of a national navy was an issue of debate among the members of the Second Continental Congress. Supporters argued that a navy would protect shipping, defend the coast, detractors countered that challenging the British Royal Navy, then the worlds preeminent naval power, was a foolish undertaking. Commander in Chief George Washington resolved the debate when he commissioned the ocean-going schooner USS Hannah to interdict British merchant ships, and reported the captures to the Congress
10.
United States Marine Corps
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The U. S. Marine Corps is one of the four armed service branches in the U. S. Department of Defense and one of the seven uniformed services of the United States. The current Chairman of the Joint Chiefs of Staff, the military officer in the U. S. Armed Forces, is a Marine Corps general, the Marine Corps has been a component of the U. S. Department of the Navy since 30 June 1834, working closely with naval forces for training, transportation, and logistics. The USMC operates posts on land and aboard sea-going amphibious warfare ships around the world, two battalions of Continental Marines were formed on 10 November 1775 in Philadelphia as a service branch of infantry troops capable of fighting for independence both at sea and on shore. The role of the Corps has since grown and evolved, expanding to aerial warfare and earning popular titles such as, Americas third air force, and, second land army. By the mid-20th century, the U. S. Marine Corps had become a major theorist of and its ability to rapidly respond on short notice to expeditionary crises gives it a strong role in the implementation and execution of American foreign policy. As of 2016, the USMC has around 182,000 active duty members and it is the smallest of the U. S. The USMC serves as an expeditionary force-in-readiness and this last clause, while seemingly redundant given the Presidents position as Commander-in-chief, is a codification of the expeditionary responsibilities of the Marine Corps. It derives from similar language in the Congressional acts For the Better Organization of the Marine Corps of 1834, in 1951, the House of Representatives Armed Services Committee called the clause one of the most important statutory – and traditional – functions of the Marine Corps. In addition to its duties, the Marine Corps conducts Visit, Board, Search, and Seizure operations, as well as missions in direct support of the White House. The Marine Band, dubbed the Presidents Own by Thomas Jefferson, Marines from Ceremonial Companies A & B, quartered in Marine Barracks, Washington, D. C. The Executive Flight Detachment also provides transport to Cabinet members. The relationship between the Department of State and the U. S. Marine Corps is nearly as old as the corps itself, for over 200 years, Marines have served at the request of various Secretaries of State. After World War II, an alert, disciplined force was needed to protect American embassies, consulates, in 1947, a proposal was made that the Department of War furnish Marine Corps personnel for Foreign Service guard duty under the provisions of the Foreign Service Act of 1946. A formal Memorandum of Agreement was signed between the Department of State and the Secretary of the Navy on December 15,1948, during the first year of the MSG program,36 detachments were deployed worldwide. Continental Marines manned raiding parties, both at sea and ashore, the Advanced Base Doctrine of the early 20th century codified their combat duties ashore, outlining the use of Marines in the seizure of bases and other duties on land to support naval campaigns. Throughout the late 19th and 20th centuries, Marine detachments served aboard Navy cruisers, battleships, Marine detachments served in their traditional duties as a ships landing force, manning the ships weapons and providing shipboard security. Marines would develop tactics and techniques of amphibious assault on defended coastlines in time for use in World War II, during World War II, Marines continued to serve on capital ships
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