Properties of Ice and Supercooled Water

Properties of Ice and Supercooled Water, 6-8 Properties of Liquid Helium, 6-132 Properties of Magnetic Materials, 12-105... 

To calculate the entropy changes, it is necessary to consider a series of reversible steps leading from liquid water at —10°C to sohd ice at —10°C. One such series might be (1) Heat supercooled water at —10°C very slowly (reversibly) to 0°C, (2) convert the water at 0°C very slowly (reversibly) to ice at 0°C, and (3) cool the ice very slowly (reversibly) from 0°C to —10°C. As each of these steps is reversible, the entropy changes can be calculated by the methods discussed previously. As S is a thermodynamic property, the sum of these entropy changes is equal to AS for the process indicated by Equation (6.97). The necessary calculations are summarized in Table 6.2, in which T2 represents 0°C and Ti represents 10°C. 

In order to achieve some understanding of the nucleation of hydrate crystals from supercooled water + gas systems, it is useful to briefly review the key properties of supercooled water (Section 3.1.1.1), hydrocarbon solubility in water (Section 3.1.1.2), and basic nucleation theory of ice, which can be applied to hydrates (since hydrate nucleation kinetics may be considered analogous, to some extent, to that of ice Section 3.1.1.3). The three subsections of 3.1.1 (i.e., supercooled water, solubility of gas in water, and nucleation) are integral parts of conceptual pictures of nucleation detailed in Section 3.1.2. 

Summit M, Baross JA (1998) Thermophilic subseafloor microorganisms from the 1996 North Gorda Ridge eruption. Deep-Sea Res II 45 2751-2766 Ter Minassian L, Pruzan P, Soulard A (1981) Thermodynamic properties of water under pressure up to 5 kbar and between 28 and 120 °C. Estimations in the supercooled region down to —40°C. J Chem Phys 75 3064-3072 Thomas DN, Dieckmann GS (2002) Antarctic sea ice—a habitat for ex-tremophiles. Science 295 641-644... 

The TV-dielectric relaxation mechanism allows us to (i) remove the THz deficit of loss e" inherent in previous (see GT2) theoretical studies, (ii) explain the THz loss and absorption spectra in supercooled (SC) water, (iii) describe, in agreement with the experiment, the low- and high-frequency tails of the two bands of ice H20 located in the range 10-300 cm-1, and (iv) describe the nonresonance loss spectrum in ice in the submillimetric region of wavelengths. Specific THz dielectric properties of SC water are ascribed to association of water molecules, revealed in our study by transverse vibration of the HB charged molecules. 

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