Kelvin, Lord principle

Thomsen regarded the heat evolved in a reaction or the decrease of energy E as a measure of the affinity. The true position was first clearly stated by Lord Rayleigh, and is based on Lord Kelvin s principle of dissipation of energy, that only those changes occur spontaneously which involve the conversion of... 

The preceding considerations are summarised in a very general principle, enunciated by Lord Kelvin in 1852, and called the... 

The application of the principle of entropy to irreversible processes has given rise to much discussion and controversy. The exposition here adopted is based on the investigations of Lord Kelvin (1852) in connexion with Dissipation of Energy. 

In spite of the fact that the general statement of this principle has been shown to be false from all standpoints, it must be admitted that its enunciation was quite in harmony with the spirit of the times the great physicists Lord Kelvin (1851) and Helmholtz (1847) had previously formulated an identical principle in connection with galvanic cells. Thomsen and Berthelot went wrong, not in tlieir enunciation of the so-called theorem as a working hypothesis, but rather in their... 

Although the principles of heat flow have lieen understood and treated mathematically since the early 19th century (Fourier, LaPlace. Poisson, Peclel. Lord Kelvin. Riemann. and many otherst. it was not until nearly... 

The operating principle of strain gauges is more than 100 years old, and it was discovered when Lord Kelvin reported that metallic conductors sub-... 

From the discussion of heat engines, the second law of thermodynamics states that it is impossible to achieve heat, taken from a reservoir, and convert it into work without simultaneous delivery of heat from the higher temperature to the lower temperature (Lord Kelvin). It also states that some work should be converted to heat in order to make heat flow from a lower to a higher temperature (Principle of Clausius). These statements acknowledge that the efficiency of heat engines could never be 100% and that heat flow from high temperatures to low temperatures is not totally spontaneous. Simply, the second law states that natural processes occur spontaneously toward the direction in which less available work can be used. 

The MRE effect, peculiar to MRE films such as Ni-Fe, was discovered by William Thompson and Lord Kelvin in 1856. Fig. 7.10.2 shows the principle of the MRE sensor. 

This is based on the principle used by Lord Kelvin (see p. 703). Konig measured the surface tension of a drop of mercury in a solution by its curvature. Mercury in a funnel was allowed to run in a fine jet into the solution and the drop connected by a wire with the mercury in the funnel. The surface tension of the drop increased to a maximum, but decreased when an external electromotive force was applied in either direction, suggesting that the drop is unchanged when the surface tension is a maximum. 

Around 1850, however, the German physicist Rudolf Clausius and the English physicist William Thomson (later Lord Kelvin) independently showed that the concept of energy conservation implied that the work capacity of heat included the actual conversion of heat into work. Clausius and Thomson each independently formulated the limits for energy conversion processes of the second law. In 1865, Clausius postulated the fundamental principle of the constant increase of entropy. 

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