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  2. Water pollution - Wikipedia

    en.wikipedia.org/wiki/Water_pollution

    A practical definition of water pollution is: "Water pollution is the addition of substances or energy forms that directly or indirectly alter the nature of the water body in such a manner that negatively affects its legitimate uses." [1]: 6 Water is typically referred to as polluted when it is impaired by anthropogenic contaminants.

  3. Water pollution in the United States - Wikipedia

    en.wikipedia.org/wiki/Water_pollution_in_the...

    Topsoil runoff from farm, central Iowa (2011). Water pollution in the United States is a growing problem that became critical in the 19th century with the development of mechanized agriculture, mining, and manufacturing industries—although laws and regulations introduced in the late 20th century have improved water quality in many water bodies. [1]

  4. Electric potential - Wikipedia

    en.wikipedia.org/wiki/Electric_potential

    The electric potential and the magnetic vector potential together form a four-vector, so that the two kinds of potential are mixed under Lorentz transformations. Practically, the electric potential is a continuous function in all space, because a spatial derivative of a discontinuous electric potential yields an electric field of impossibly ...

  5. Electrochemical potential - Wikipedia

    en.wikipedia.org/wiki/Electrochemical_potential

    In generic terms, electrochemical potential is the mechanical work done in bringing 1 mole of an ion from a standard state to a specified concentration and electrical potential. According to the IUPAC definition, [4] it is the partial molar Gibbs energy of the substance at the specified electric potential, where the substance is in a specified ...

  6. Electrorheological fluid - Wikipedia

    en.wikipedia.org/wiki/Electrorheological_fluid

    There are two main theories to explain the effect: the interfacial tension or 'water bridge' theory, [4] and the electrostatic theory. The water bridge theory assumes a three phase system, the particles contain the third phase which is another liquid (e.g. water) immiscible with the main phase liquid (e.g. oil).

  7. Electrostatic precipitator - Wikipedia

    en.wikipedia.org/wiki/Electrostatic_precipitator

    A negative side-effect of electrostatic precipitation devices is the potential production of toxic ozone [13] and NO x. [14] However, electrostatic precipitators offer benefits over other air purifications technologies, such as HEPA filtration, which require expensive filters and can become "production sinks" for many harmful forms of bacteria ...

  8. Poisson's equation - Wikipedia

    en.wikipedia.org/wiki/Poisson's_equation

    Siméon Denis Poisson. Poisson's equation is an elliptic partial differential equation of broad utility in theoretical physics.For example, the solution to Poisson's equation is the potential field caused by a given electric charge or mass density distribution; with the potential field known, one can then calculate the corresponding electrostatic or gravitational (force) field.

  9. United States regulation of point source water pollution

    en.wikipedia.org/wiki/United_States_regulation...

    Water pollution is the contamination of natural water bodies by chemical, physical, radioactive or pathogenic microbial substances. [2] Point sources of water pollution are described by the CWA as "any discernible, confined, and discrete conveyance from which pollutants are or may be discharged."