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The "German question" was a debate in the 19th century, especially during the Revolutions of 1848, over the best way to achieve a unification of all or most lands inhabited by Germans. [1] From 1815 to 1866, about 37 independent German-speaking states existed within the German Confederation .
The figure shows one such ideal expansion fan. A supersonic expansion fan, technically known as Prandtl–Meyer expansion fan, a two-dimensional simple wave, is a centered expansion process that occurs when a supersonic flow turns around a convex corner. The fan consists of an infinite number of Mach waves, diverging from a sharp corner. When a ...
Scanning joule expansion microscopy is based on the contact operation model of atomic force microscopy. During the operation, the tip on the cantilever is brought into contact with the surface of the sample. AC or pulsed electrical signal is applied to the sample creating Joule heating and resulting in periodic thermal expansion. [2]
In thermodynamics, the Joule–Thomson effect (also known as the Joule–Kelvin effect or Kelvin–Joule effect) describes the temperature change of a real gas or liquid (as differentiated from an ideal gas) when it is expanding; typically caused by the pressure loss from flow through a valve or porous plug while keeping it insulated so that no heat is exchanged with the environment.
A number of materials contract on heating within certain temperature ranges; this is usually called negative thermal expansion, rather than "thermal contraction".For example, the coefficient of thermal expansion of water drops to zero as it is cooled to 3.983 °C (39.169 °F) and then becomes negative below this temperature; this means that water has a maximum density at this temperature, and ...
The virial expansion is a model of thermodynamic equations of state. It expresses the pressure P of a gas in local equilibrium as a power series of the density . This equation may be represented in terms of the compressibility factor , Z , as Z ≡ P R T ρ = A + B ρ + C ρ 2 + ⋯ {\displaystyle Z\equiv {\frac {P}{RT\rho }}=A+B\rho +C\rho ^{2 ...
The Big Bang is a physical theory that describes how the universe expanded from an initial state of high density and temperature. [1] The concept of an expanding universe was scientifically originated by physicist Alexander Friedmann in 1922 with the mathematical derivation of the Friedmann equations.
An extreme example of pendelluft is found in a spontaneously breathing patient with an open hemithorax [3] or large flail segment. [4] During the inspiratory phase, the contralateral lung (with a closed / intact chest wall) will expand with most of the tidal volume, with the open plura or paradoxical chest wall movement preventing expansion of the ipsilateral lung.