phase diagram


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phase diagram,

graph that shows the relation between the solid, liquid, and gaseous states of a substance (see states of matterstates of matter,
forms of matter differing in several properties because of differences in the motions and forces of the molecules (or atoms, ions, or elementary particles) of which they are composed.
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) as a function of the temperature and pressure. The graph is divided into three regions, one for each of the physical states, and it specifies the range of temperatures at which the substance exists in each state for any value of the pressure. For example, a phase diagram for water shows that at a pressure of 1 atmosphere water is a solid up to a temperature of 0°C;, a liquid from 0°C; to 100°C;, and a gas above 100°C;. At a pressure of 0.5 atmospheres, the graph shows that although the melting point of ice remains 0°C;, the boiling point of water is lowered to 82°C;. Each substance has its own phase diagram, which must be determined experimentally. The border between two regions on the graph represents an equilibrium state, such as a melting point or boiling point, at which two states can coexist (see chemical equilibriumchemical equilibrium,
state of balance in which two opposing reversible chemical reactions proceed at constant equal rates with no net change in the system. For example, when hydrogen gas, H2, and iodine gas, I2
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). The point at which all three regions meet is called the triple point; at these conditions of temperature and pressure, the solid, liquid, and gaseous states can coexist in equilibrium. The triple-point conditions for water are a temperature of .01°C; and a pressure of .006 atmospheres.

phase diagram

[′fāz ‚dī·ə‚gram]
(metallurgy)
(physical chemistry)
A graphical representation of the equilibrium relationships between phases (such as vapor-liquid, liquid-solid) of a chemical compound, mixture of compounds, or solution.
(thermodynamics)
A graph showing the pressures at which phase transitions between different states of a pure compound occur, as a function of temperature.
A graph showing the temperatures at which transitions between different phases of a binary system occur, as a function of the relative concentrations of its components.
References in periodicals archive ?
Phase behavior of microemulsion reflected by the pseudo-ternary phase diagram is a key parameter of the application of PDILMs.
Graphical representations of the positions of the zero contours of the second derivative (a) and the third derivative (b) of the free energy in the Hg-Mn-Te-Se system at the cross section for the existence of solid solutions of the phase diagram
One of the major goals of the RHIC and LHC studies is to obtain information on the quantum chromodynamics (QCD) phase diagram [1].
Figure 6 shows two projections from the phase diagram on both X-Y and X-Z planes for [alpha] = 500, R = 75, [sigma].sub.1] = 6.2, and [eta] = 0.
Under these assumptions, when no prestress is applied, s = 0, by solving the governing equations (16), the dynamic stability evolution and performance of the viscoelastic elastomer, such as the oscillation diagram, the hysteresis loop, the phase diagram, and the Poincare map, are simulated.
Using code embedded in a single function developed in Matlab, we portray the global dynamics of the model using different parameter values by means of an illustration that includes, not only the evolution of real output and inflation throughout time but also a phase diagram that fully describes the qualitative properties of its equilibria and the transition dynamics.
Caption: Figure 2: Phase diagram of the ternary system (NaCl + C[H.sub.3]OH + [H.sub.2]O) at 298.15 K.
The waveform and phase diagram are shown in Figure 5(a).
Gao [56] made a pH-Eh phase diagram at T = 323.8 K, based on which they affirmed that minerals zoning is controlled by pH under reducing condition.
A review of the phase diagram showed a promising eutectic composition at approximately 10 wt% cerium that suggested the alloy could be cast.