Studies of the Effective Thermal Conductivity of Sandstone Under High Pressure and Temperature

Effect of Pressure on the Temperature Dependence of the Thermal Conductivity of Arsenic Chalcogenide with Different Ordering

“…As we showed in [1][2][3], the temperature dependence of effective thermal conductivity λ of most composite materials at fixed pressures is governed by the power law (1) The wave nature of heat transfer in crystals is reflected in temperature dependence (1) with coefficient n ≅ 1 [4,5]. We also arrive at (1) under the activation-type mechanism of heat transfer in amorphous bodies, but with coefficient n ≅ 0.5.…”

“…When it reaches the block boundaries, this frequency brings them into an excited nonequilibrium state [3]. Numerous experiments have thus shown [1][2][3] there is pronounced nonlinearity of growth (especially at the initial stage). Exponent n in the temperature dependence changes while maintaining its power character.…”

Effect of Structural Ordering, Temperature, and Pressure on Processes of Heat Transfer in Minerals and Alloys

“…Numerous data of our own [8][9][10] and from the literature [12][13][14][15][16][17][18][19][20][21] show that n = −1 for ordered minerals and alloys; n = −0.5 for partially ordered minerals and alloys; n = 0 when the degree of disorder in minerals and alloys is ε = 36.4% [18]; and n = 0.5 for when the structure of minerals and rocks is amorphous (with no long-range translational bonds between atoms). The temperature dependence of the efficient thermal conductivity of minerals and rocks thus lies within the narrow domain of to and provides an estimate of their degree of disorder ε.…”

“…In amorphous and glassy minerals and alloys with no long-range translational bonds between atoms, efficient thermal conductivity depends weakly on temperature. A review of the literature data [6][7][8][9][10][11] shows † Deceased.…”

“…Our recent works were dedicated to revealing the relationship between exponent n and other characteristics of a composite compound [8][9][10]. This work presents experimental results from determining the efficient thermal conductivity of sandstone samples (Aktash deposit, Republic of Dagestan: depth, 2970 m; density, 2.7 × 10 3 kg m −3 ; open porosity k = 5%) in the 273-523 K range of temperatures at a hydrostatic pressure of 0.1-400 MPa (measured using absolutely stationary flat plates [10]). The relationship between the value and sign of n and degree of structural disor-…”