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Meander (other)
A meander is one of a series of regular sinuous curves in the channel of a river or other watercourse. It is produced as a watercourse erodes the sediments of an outer, concave bank ( cut bank or river cliff) and deposits sediments on an inner, convex bank which is typically a point bar. The result of this coupled erosion and sedimentation is the formation of a sinuous course as the channel migrates back and forth across the axis of a floodplain. The zone within which a meandering stream periodically shifts its channel is known as a meander belt. It typically ranges from 15 to 18 times the width of the channel. Over time, meanders migrate downstream, sometimes in such a short time as to create civil engineering challenges for local municipalities attempting to maintain stable roads and bridges.Neuendorf, K.K.E., J.P. Mehl Jr., and J.A. Jackson, J.A., eds. (2005) ''Glossary of Geology'' (5th ed.). Alexandria, Virginia, American Geological Institute. 779 pp. Charlton, R., 2007. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the Roman Republic it became the dominant language in the Italian region and subsequently throughout the Roman Empire. Even after the fall of Western Rome, Latin remained the common language of international communication, science, scholarship and academia in Europe until well into the 18th century, when other regional vernaculars (including its own descendants, the Romance languages) supplanted it in common academic and political usage, and it eventually became a dead language in the modern linguistic definition. Latin is a highly inflected language, with three distinct genders (masculine, feminine, and neuter), six or seven noun cases (nominative, accusative, genitive, dative, ablative, and vocative), five declensions, four ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prussian Academy Of Sciences
The Royal Prussian Academy of Sciences (german: Königlich-Preußische Akademie der Wissenschaften) was an academy established in Berlin, Germany on 11 July 1700, four years after the Prussian Academy of Arts, or "Arts Academy," to which "Berlin Academy" may also refer. In the 18th century, it was a French-language institution since French was the language of science and culture during that era. Origins Prince-elector Frederick III of Brandenburg, Germany founded the Academy under the name of ''Kurfürstlich Brandenburgische Societät der Wissenschaften'' ("Electoral Brandenburg Society of Sciences") upon the advice of Gottfried Wilhelm Leibniz, who was appointed president. Unlike other Academies, the Prussian Academy was not directly funded out of the state treasury. Frederick granted it the monopoly on producing and selling calendars in Brandenburg, a suggestion from Leibniz. As Frederick was crowned " King in Prussia" in 1701, creating the Kingdom of Prussia, the Academy wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meander Cutoff
A meander cutoff is a natural form of a cutting or cut in a river occurs when a pronounced meander (hook) in a river is breached by a flow that connects the two closest parts of the hook to form a new channel, a full loop. The steeper drop in gradient (slope) causes the river flow gradually to abandon the meander which will silt up with sediment from deposition. Cutoffs are a natural part of the evolution of a meandering river. Rivers form meanders as they flow laterally downstream, see sinuosity. Meandering rivers flow higher and hence with more total flow, pressure and erosion on the outside of their bends due to forming a vortex as in a stirred coffee cup and consequently the river erodes more the outer bank. On the inside bend of a river, the level is lower, secondary flow moves sand and gravel across the river bed creating shallows and point bars, and friction of air and perturbances of the bed act against a higher proportion of the column of water, being shorter, slowing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shear Stress
Shear stress, often denoted by (Greek: tau), is the component of stress coplanar with a material cross section. It arises from the shear force, the component of force vector parallel to the material cross section. '' Normal stress'', on the other hand, arises from the force vector component perpendicular to the material cross section on which it acts. General shear stress The formula to calculate average shear stress is force per unit area.: : \tau = , where: : = the shear stress; : = the force applied; : = the cross-sectional area of material with area parallel to the applied force vector. Other forms Wall shear stress Wall shear stress expresses the retarding force (per unit area) from a wall in the layers of a fluid flowing next to the wall. It is defined as: \tau_w:=\mu\left(\frac\right)_ Where \mu is the dynamic viscosity, u the flow velocity and y the distance from the wall. It is used, for example, in the description of arterial blood flow in which case which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boundary Layer
In physics and fluid mechanics, a boundary layer is the thin layer of fluid in the immediate vicinity of a bounding surface formed by the fluid flowing along the surface. The fluid's interaction with the wall induces a no-slip boundary condition (zero velocity at the wall). The flow velocity then monotonically increases above the surface until it returns to the bulk flow velocity. The thin layer consisting of fluid whose velocity has not yet returned to the bulk flow velocity is called the velocity boundary layer. The air next to a human is heated resulting in gravity-induced convective airflow, airflow which results in both a velocity and thermal boundary layer. A breeze disrupts the boundary layer, and hair and clothing protect it, making the human feel cooler or warmer. On an aircraft wing, the velocity boundary layer is the part of the flow close to the wing, where viscous forces distort the surrounding non-viscous flow. In the Earth's atmosphere, the atmospheric b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irrotational Vortex
In fluid dynamics, a vortex ( : vortices or vortexes) is a region in a fluid in which the flow revolves around an axis line, which may be straight or curved. Vortices form in stirred fluids, and may be observed in smoke rings, whirlpools in the wake of a boat, and the winds surrounding a tropical cyclone, tornado or dust devil. Vortices are a major component of turbulent flow. The distribution of velocity, vorticity (the curl of the flow velocity), as well as the concept of circulation are used to characterise vortices. In most vortices, the fluid flow velocity is greatest next to its axis and decreases in inverse proportion to the distance from the axis. In the absence of external forces, viscous friction within the fluid tends to organise the flow into a collection of irrotational vortices, possibly superimposed to larger-scale flows, including larger-scale vortices. Once formed, vortices can move, stretch, twist, and interact in complex ways. A moving vortex carri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Flow
In fluid dynamics, flow can be decomposed into primary plus secondary flow, a relatively weaker flow pattern superimposed on the stronger primary flow pattern. The primary flow is often chosen to be an exact solution to simplified or approximated (for instance, inviscid) governing equations, such as potential flow around a wing or geostrophic current or wind on the rotating Earth. In that case, the secondary flow usefully spotlights the effects of complicated real-world terms neglected in those approximated equations. For instance, the consequences of viscosity are spotlighted by secondary flow in the viscous boundary layer, resolving the tea leaf paradox. As another example, if the primary flow is taken to be a balanced flow approximation with net force equated to zero, then the secondary circulation helps spotlight acceleration due to the mild imbalance of forces. A smallness assumption about secondary flow also facilitates linearization. In engineering secondary flow also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicoidal Flow
Helicoidal flow is the cork-screw-like flow of water in a meander. It is one example of a secondary flow. Helicoidal flow is a contributing factor to the formation of slip-off slopes and river cliffs in a meandering section of the river. The helicoidal motion of the flow aids the processes of hydraulic action and corrasion Corrasion is a geomorphological term for the process of mechanical erosion of the earth's surface caused when materials are transported across it by running water, waves, glaciers, wind or gravitational movement downslope. An example is the wear ... on the outside of the meander, and sweeps sediment across the floor of the meander towards the inside of the meander, forming point bar deposits. See also * Laminar flow * Turbulent flow * Baer's law * Secondary flow in river bends References Bibliography Journal of Geophysical Research, Volume 107 (2002) Rivers {{Fluiddynamics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bend2
Bend may refer to: Materials * Bend, a curvature in a pipe, tube, or pipeline (see Bend radius) * Bend knot, a knot used to tie two ropes together; see List of bend knots *Bending, the deformation of an object due to an applied load Music Musical techniques * Bend (guitar), a guitar technique * Bending, for blues harp (harmonica) Albums and songs * ''Bend'' (8stops7 album), 2006 * ''Bend'' (The Origin album), 1992 * "Bend" (song), a 2015 song by Chet Faker People * Lin Bend (1922–1978), Canadian ice hockey centre * Robert Bend (1914–1999), Manitoba politician Places * Bend, British Columbia, a railway point in Canada * Bend, California * Bend, Missouri * Bend, Oregon * Bend, South Dakota * Bend, Texas Other uses * Bend (heraldry), a diagonal band used as a heraldic charge * Bend, a meander in a river * Decompression sickness, commonly known as "the bends" * Curl (association football), a playing technique also called "bend" See also * * * Bends (disambiguati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graben
In geology, a graben () is a depressed block of the crust of a planet or moon, bordered by parallel normal faults. Etymology ''Graben'' is a loan word from German, meaning 'ditch' or 'trench'. The word was first used in the geologic context by Eduard Suess in 1883. The plural form is either ''graben'' or ''grabens''. Formation A graben is a valley with a distinct escarpment on each side caused by the displacement of a block of land downward. Graben often occur side by side with horsts. Horst and graben structures indicate tensional forces and crustal stretching. Graben are produced from parallel normal faults, where the displacement of the hanging wall is downward, while that of the footwall is upward. The faults typically dip toward the center of the graben from both sides. Horsts are parallel blocks that remain between graben; the bounding faults of a horst typically dip away from the center line of the horst. Single or multiple graben can produce a rift valley. Ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miletus
Miletus (; gr, Μῑ́λητος, Mī́lētos; Hittite transcription ''Millawanda'' or ''Milawata'' ( exonyms); la, Mīlētus; tr, Milet) was an ancient Greek city on the western coast of Anatolia, near the mouth of the Maeander River in ancient Ionia. Its ruins are located near the modern village of Balat in Aydın Province, Turkey. Before the Persian rule that started in the 6th century BC, Miletus was considered among the greatest and wealthiest of Greek cities. Evidence of first settlement at the site has been made inaccessible by the rise of sea level and deposition of sediments from the Maeander. The first available evidence is of the Neolithic. In the early and middle Bronze Age the settlement came under Minoan influence. Legend has it that an influx of Cretans occurred displacing the indigenous Leleges, and the site was renamed Miletus after a place in Crete. Recorded history at Miletus begins with the records of the Hittite Empire, and the Mycenaean records ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
