Heat, theories mechanical theory

In an obituaiy talk given at the Physical Society of Berlin in 1889, Hermann Helmholtz stressed that Clausius s strict formulation of the mechanical heat theory is one of the most surprising and interesting achievements of the old and new physics, because of the absolute generality independent of the nature of the physical body and since it establishes new, unforeseen relations between different branches of physics. 

The equations of 59—61 are independent of the mechanical, theory of heat, and would apply equally well to the caloric theory. In the latter case, however, SQ is a perfect differential. They are also unchanged when T is put for 6, where T is the absolute temperature. All the twelve relations can be derived from the four in the first column, together with the equations (4). 

The problem has been largely worked at from both sides from the theoretical side the point of view has been almost exclusively that of the kinetic gas theory. It must be kept in mind, however, that it is possible that a purely mechanical theory may not be sufficient to cover the phenomena, as has recently appeared in the case of the specific heats of solids. 

Spectroscopic Methods, [Biological] Applications of Spectroscopy, EPR, Recent Advances in (Smaller). Spectroscopy, Infrared, Use in Biology (Lecomte). Spectroscopy of Transition-Group Complexes (Jorgensen) Statistical-Mechanical Theory of Transport Processes. X. The Heat of Transport in Binary Liquid Systems (Bearman, Kirkwood, Fixman). ... 

R. Clausius, Mechanical Theory of Heat, John van Voorst, London, 1867. 

Experiments indicate that the smooth variations of thermodynamic properties (e.g., V, Ky, and the specific heat at constant pressure Cp) with temperature are intermpted by the kinetic process of glass formation, leading to cooling rate dependent kinks in these properties as a function of temperature. In our view, these kinks cannot be described by an equilibrium statistical mechanical theory, but rather are a challenge for a nonequilibrium theory of glass formation. Nonetheless, some insight into the origin of these kinks and the qualitative... 

Statistical-Mechanical Theory of Transport Processes. X. The Heat of Transport in Binary Liquid Systems (Bearman, Kirkwood, ... 

Clausius was an ardent nationalist and patriot. In the Franco-German war of 1870, he took leave of his university duties to enlist (nearing age 50 ) for duties at the front, earning the Iron Cross in 1871. He commanded an ambulance corps of students recmited from Bonn that removed wounded soldiers from front-line action. In one of these engagements, he suffered a leg injury that left him disabled and in pain for life. His passionate advocacy of Germanic culture later led to unfortunate disputes with Thomson, Tait, Maxwell, and others over personal or nationalistic priority for the mechanical theory of heat, the first law, and other discoveries. 

Combustion models which consider the thickness of the reaction zone usually accentuate cither heat conduction mechanisms (thermal theory) or the diffusion mechanisms (diffusion theory) and the models are of necessity of limited value. Simpler models in which the reaction zone or flame front is considered to be an infinitesimally thin discontinuity in the flow, while not simulating exactly the observed conditions, allow the model to be of more general utility and many combustion phenomena become easier to understand because of this simplification. It is the latter approach which is discussed first in this paper—i.e., the combustion process is regarded as a wave phenomenon. 

R. Clausius. The Mechanical Theory of Heat With Its Applications to the Steam-Engine and to the Physical Properties of Bodies. Van Voorst, London, 1867. 

Clausius R (1867) The mechanical theory of heat. English translation, Hirst T (ed). John Van Voorst, London... 

Most of modern physics and chemistry is bast d on three fundamental ideas first, matter is made of atoms and molecules, very small and very numerous second, it is impossible in principle to observe details of atomic and molecular motions below a certain scale of smallness and third, heat is mechanical motion of the atoms and molecules, on such a small scale that it cannot be completely observed. The first and third of these ideas are products of the last century, but the second, the uncertainty principle, the most characteristic result of the quantum theory, has arisen since 1000. By combining these three principles, we have the theoretical foundation for studying the branches of physics dealing with matter and chemical problems. 

Jan. 1, 1822, Koslin, Germany, now Koszalin, Poland -Aug. 25,1888, Bonn, Germany) Clausius studied mathematics and physics at the University of Berlin 1840-1844, dissertation on reflection of light in the sky at Halle University 1847, 1850 first paper on mechanical theory of heat, 1850 professor at the Royal Artillery and Engineering School in Berlin, 1855 Chair of Mathematical Physics at the Polytechnikum in Zurich and professor at the University of Zurich, 1867 professor at the University of Wurzburg, 1869 chair at the University of Bonn, work on first and second laws of thermodynamics. 

Watt, like Black, was committed to one of three major views of heat extant at the time. The first of the three views was that heat was motion, or the vibration of the parts of ordinary material bodies. This mechanical theory of heat had been favoured by Boyle and had been endorsed by Newton. But the mechanical theory was not fashionable in the mid- to late eighteenth century. We know that a mathematical theory of heat as motion was developed by Henry Cavendish in the 1780s but, typically, not published.42 This type of theory was, of course, to become the correct view of heat by the mid-nineteenth century. The second and third accounts of heat are often collapsed together as material theories since in both heat was a special substance rather than the motion of ordinary matter. The distinction between these two material theories is clearly described by McCormmach ... 

The rest of his history of heat involves Joule paying obeisance to the work of Rumford and Davy, which he regarded as decisive in favour of the mechanical theory of heat. However, frivolous objections led to it being forgotten so that the several naturalists who more recendy have recommenced the enquiry have done so quite independently, and on ground of their own selection . Watt disappears from the lecture for a while, as Joule recounts his own work and that of Thomson and Rankine. But, in concluding, Joule says this ... 

Watt to Black, 24 July 1779 in Robinson and McKie, Partners in Science, pp. 65-6, on p. 66. The reference is to P. J. Macquer, Dictionnaire de Chymie (Paris, 1766 2nd edn, revised and enlarged, 1778). I do not know who could have been teasing Watt in this way. It is usually considered that advocacy of mechanical theories of heat was quite rare during this period. 

Different biopolymers are used when the texture-building capacity of protein alone, for instance, is insufficiently capable to create the target structure. However, phase separation effects can occur, as described in theory and technical detail in other chapters of this publication. These phenomena are also dependent on processing factors such as heat or mechanical treatment, the latter effects being rarely investigated so far. 

The self-consistent theoretical models based on the Boltzmann transport theory are used to characterize the microscale heat transfer mechanism by explaining mutual interactions among lattice temperature, and number density and temperature of carriers [12]. Especially, a new parameter related with non-equilibrium durability is introduced and its characteristics for various laser pulses and fluences are discussed. This study also investigates the temporal characteristics of carrier temperature distribution, such as the one- and two-peak structures, according to laser pulses and fluences, and establishes a regime criterion between one-peak and two-peak sttuctures for picosecond laser pulses. 

The classical researches of Ludwig Boltzmann showed how this apparent contradiction could be explained, and how the mechanical theory of heat could be established on a firm basis, namely, by the hypothesis that heat consists of a chaotic (molecular ungeordnet) motion of the ultimate particles. ... 

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