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Information about Dissipation

In physics, dissipation embodies the concept of a dynamical system where important mechanical modes, such as waves or oscillations, lose energy over time, typically due to the action of friction or turbulence. The lost energy is converted into heat, raising the temperature of the system. Such systems are called dissipative systems.

For example, a wave that loses amplitude is said to dissipate. The precise nature of the effects depends on the nature of the wave: an atmospheric wave, for instance, may dissipate close to the surface due to friction with the land mass, and at higher levels due to radiative cooling.

Dissipating forces are those which can not be described by Hamiltonian formalism. Loosely speaking, friction and all similar forces which result in decoherency of energy, that is, conversion of coherent or directed energy flow into an indirected or more isotropic distribution of energy.

In computational physics, a numerical dissipation is also known as "artificial dissipation" or "artificial diffusion" or "numerical diffusion". They all mean this: when the pure advection equation--which, by definition, is free of dissipation--is solved by a numerical approximation method that reduces the amplitude and changes the shape of the initial wave in a way analogous to a diffusional process, the method is said to contain 'dissipation'.

A formal, mathematical definition of dissipation, as commonly used in the mathematical study of measure-preserving dynamical systems, is given in the article wandering set.

In river hydrology

Dissipation is the process of converting mechanical energy of downward flowing water into thermal and acoustical energy. Various devices are designed in streambeds to reduce the kinetic energy of flowing waters to reduce their erosive potential on banks and river bottoms. Very often these devices look like small waterfalls or cascades, where water flows vertically or over riprap to lose some of its kinetic force.

See also

Physics is the science of matter[1] and its motion[2][3], as well as space and time[4][5] —the science that deals with concepts such as force, energy, mass, and charge.
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dynamical system concept is a mathematical formalization for any fixed "rule" which describes the time dependence of a point's position in its ambient space. Examples include the mathematical models that describe the swinging of a clock pendulum, the flow of water in a pipe, and
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wave is a mode of energy transfer from one place to another, often with little or no permanent displacement of the particles of the medium (i.e. little or no associated mass transport); instead there are oscillations around almost fixed positions.
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''For other uses, see oscillator (disambiguation)
Oscillation is the variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states.
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energy (from the Greek ενεργός, energos, "active, working")[1] is a scalar physical quantity that is a property of objects and systems of objects which is conserved by nature.
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time.

One view is that time is part of the fundamental structure of the universe, a dimension in which events occur in sequence, and time itself is something that can be measured.
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Friction is the force of two surfaces in contact. It is not a fundamental force, as it is derived from electromagnetic forces between atoms. When contacting surfaces move relative to each other, the friction between the two objects converts kinetic energy into thermal energy, or
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turbulence or turbulent flow is a flow regime characterized by chaotic, stochastic property changes. This includes low momentum diffusion, high momentum convection, and rapid variation of pressure and velocity in space and time.
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Thermodynamics (from the Greek θερμη, therme, meaning "heat" and δυναμις, dynamis, meaning "power") is a branch of physics that studies the effects of changes in temperature, pressure, and volume on
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trillion fold).]]

Temperature is a physical property of a system that underlies the common notions of hot and cold; something that is hotter generally has the greater temperature. Temperature is one of the principal parameters of thermodynamics.
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dissipative system (or dissipative structure) is a thermodynamically open system which is operating far from thermodynamic equilibrium in an environment with which it exchanges energy, matter and/or entropy.
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wave is a mode of energy transfer from one place to another, often with little or no permanent displacement of the particles of the medium (i.e. little or no associated mass transport); instead there are oscillations around almost fixed positions.
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amplitude is a nonnegative scalar measure of a wave's magnitude of oscillation, that is, the magnitude of the maximum disturbance in the medium during one wave cycle.

Sometimes this distance is called the peak amplitude
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An atmospheric wave is a periodic disturbance in the fields of atmospheric variables (like surface pressure or geopotential height, temperature, or wind velocity) which may either propagate (traveling wave) or not (stationary wave).
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Friction is the force of two surfaces in contact. It is not a fundamental force, as it is derived from electromagnetic forces between atoms. When contacting surfaces move relative to each other, the friction between the two objects converts kinetic energy into thermal energy, or
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Radiative cooling is the condition in which a body loses more energy by radiation than it gains from its surroundings.

Meteorological effects

The large-scale circulation of the Earth's atmosphere is driven by the difference in absorbed solar radiation per square meter, as
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Hamiltonian may refer to

In mathematics:
  • Hamiltonian system
  • Hamilton's equations
  • Hamiltonian path, in graph theory
  • Hamiltonian group, in group theory
  • Hamiltonian (control theory)
  • Hamiltonian flow
  • Hamiltonian vector field
In
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Coherence or coherent can refer to:
  • Coherence (cognitive science), a property of mental/cognitive states
  • Coherence (linguistics), what makes a text semantically meaningful
  • Coherence (physics), a property of waves
  • Quantum coherence

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Direction may refer to:
  • Direction (geometry, geography)
  • Relative direction, for instance left, right, forward, backward, up, and down
  • Film direction, the management, supervision, or guidance of a film

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Isotropy (the opposite of anisotropy) is the property of being independent of direction. Isotropic radiation has the same intensity regardless of the direction of measurement, and an isotropic field exerts the same action regardless of how the test particle is oriented.
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Computational physics is the study and implementation of numerical algorithms in order to solve problems in physics for which a quantitative theory already exists. It is often regarded as a subdiscipline of theoretical physics but some consider it an intermediate branch between
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Advection is transport in a fluid. The fluid is described mathematically for such processes as a vector field, and the material transported is described as a scalar concentration of substance, which is present in the fluid.
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In mathematics, a measure-preserving dynamical system is an object of study in the abstract formulation of dynamical systems, and ergodic theory in particular.

Definition


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wandering set formalizes a certain idea of movement and mixing in such systems. When a dynamical system has a wandering set of non-zero measure, then the system is a dissipative system.
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Erosion is displacement of solids (soil, mud, rock and other particles) usually by the agents of currents such as, wind, water, or ice by downward or down-slope movement in response to gravity or by living organisms (in the case of bioerosion).
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stream bed is the channel bottom of a stream or river or creek; the physical confine of the normal water flow. The lateral confines (channel margins) during all but flood stage are known as the stream banks or river banks.
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A waterfall is usually a geological formation resulting from water, often in the form of a stream, flowing over an erosion-resistant rock formation that forms a sudden break in elevation or nickpoint.
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A cascade is a waterfall or a series of waterfalls.

Cascade may also refer to:

Places

North America

  • Cascade Range, a mountain range on the west coast of North America

Canada


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Riprap (also known as rip rap, rubble, revetment, shot rock or rock armour) usually made by crushing or blasting, or from scree, is more effective at ground reinforcement than round river rock.
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kinetic energy of an object is the extra energy which it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its current velocity.
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