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| :''For other uses, see '''[[electric vehicle]]'''.''
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| :''For the electrical mobility of an [[electron]] or [[electron hole|hole]] in [[solid-state physics]], see '''[[Electron mobility]]'''.''
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| '''Electrical mobility''' is the ability of charged particles (such as [[electron]]s or [[proton]]s) to move through a medium in response to an [[electric field]] that is pulling them. The separation of ions according to their mobility in gas phase is called [[Ion mobility spectrometry]], in liquid phase it is called [[electrophoresis]].
| | cepillos para el cabello Paddle son planas y anchas. Ayudan en el cepillado de pelo largo y para estilizar ella. Cepillar el cabello con un cepillo de paleta también le da un masaje ligero cuero cabelludo. Estos cepillos se utilizan para capas de estilo, ya que no añaden volumen a las capas. ¿Qué o:. Utilice un peine de cola de rata para dividir el cabello en - secciones, en función del espesor del cabello. Cuanto más apretado los rizos del cabello, más secciones que van a necesitar. |
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| ==Theory==
| | El perdedor del modelo del rizo, se necesitan los menos secciones.<br><br>Should you loved this informative article and you wish to receive more info concerning [http://tinyurl.com/qhycvg3 http://tinyurl.com/qhycvg3] assure visit our own page. |
| When a [[charged particle]] in a [[gas]] or [[liquid]] is acted upon by a uniform [[electric field]], it will be accelerated until it reaches a constant [[drift velocity]] according to the formula:
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| : <math>\,v_d = \mu E</math>
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| where
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| * <math>\, v_d</math> is the drift velocity (m/s)
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| * <math>\, E</math> is the magnitude of the applied electric field (V/m)
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| * <math>\, \mu</math> is the mobility (m<sup>2</sup>/(Vs))
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| In other words, the electrical mobility of the particle is defined as the ratio of the drift velocity to the magnitude of the electric field:
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| : <math>\,\mu = \frac{v_d}{E}</math>
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| Electrical mobility is proportional to the net [[electric charge|charge]] of the particle. This was the basis for [[Robert Millikan]]'s demonstration that electrical charges occur in discrete units, whose magnitude is the charge of the [[electron]].
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| Electrical mobility of spherical particles much larger than the mean free path of the molecules of the medium is inversely proportional to the [[diameter]] of the particles; for spherical particles much smaller than the mean free path, the electrical mobility is inversely proportional to the square of the particle diameter.
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| ==Mobility in gas phase==
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| Mobility is defined for any species in the gas phase, encountered mostly in [[Plasma (physics)|plasma]] physics and is defined as:
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| :<math>\mu = \frac{q}{m\, \nu_m}</math>
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| where
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| *<math>\, q</math> is the charge of the species,
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| *<math>\, \nu_m</math> is the momentum transfer collision frequency, and
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| *<math>\, m</math> is the mass.
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| Mobility is related to the species' '''diffusion coefficient''' <math>\, D</math> through an exact (thermodynamically required) equation known as the [[Einstein_relation_(kinetic_theory)|Einstein relation]]:
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| :<math>\mu = \frac{q}{k\, T}D</math>,
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| where
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| *<math>\, k</math> is the [[Boltzmann constant]],
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| *<math>\, T</math> is the [[gas]] temperature, and
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| *<math>\, D</math> is a measured quantity that can be estimated. If one defines the [[mean free path]] in terms of [[momentum transfer]], then one gets:
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| :<math>D = \frac{\pi}{8}\lambda^2 \nu_m</math>.
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| But both the ''momentum transfer mean free path'' and the ''momentum transfer collision frequency'' are difficult to calculate. Many other mean free paths can be defined. In the gas phase, <math>\, \lambda</math> is often defined as the diffusional mean free path, by assuming a simple approximate relation is exact:
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| :<math>D = \frac{1}{2}\lambda \,v</math>,
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| when <math>\, v</math> is the [[root mean square]] speed of the gas molecules:
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| :<math>v = \sqrt {{3\, k\, T}\over{m}}</math>
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| where <math>\, m</math> is the mass of the diffusing species. This approximate equation becomes exact when used to define the diffusional mean free path.
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| ==Applications==
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| Electrical mobility is the basis for [[electrostatic precipitation]], used to remove particles from exhaust gases on an industrial scale. The particles are given a charge by exposing them to ions from an [[electrical discharge]] in the presence of a strong field. The particles acquire an electrical mobility and are driven by the field to a collecting electrode.
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| Instruments exist which select particles with a narrow range of electrical mobility, or particles with electrical mobility larger than a predefined value.<ref>{{cite journal | author=E. O. Knutson and K. T. Whitby | title=Aerosol classification by electric mobility: Apparatus, theory, and applications | journal=J. Aerosol Sci. | year=1975 | volume=6 | pages=443–451 | doi=10.1016/0021-8502(75)90060-9 | issue=6}}</ref> The former are generally referred to as "differential mobility analyzers". The selected mobility is often identified with the diameter of a singly charged spherical particle, thus the "electrical-mobility diameter" becomes a characteristic of the particle, regardless of whether it is actually spherical.
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| ==References==
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| {{Reflist}}
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| [[Category:Physical quantities]]
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| [[Category:Electrophoresis]]
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| [[Category:Mass spectrometry]]
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cepillos para el cabello Paddle son planas y anchas. Ayudan en el cepillado de pelo largo y para estilizar ella. Cepillar el cabello con un cepillo de paleta también le da un masaje ligero cuero cabelludo. Estos cepillos se utilizan para capas de estilo, ya que no añaden volumen a las capas. ¿Qué o:. Utilice un peine de cola de rata para dividir el cabello en - secciones, en función del espesor del cabello. Cuanto más apretado los rizos del cabello, más secciones que van a necesitar.
El perdedor del modelo del rizo, se necesitan los menos secciones.
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