Intensification of foam technology by the energy of the electrohydrothermal force field. Part 1. Analysis of the features of generating internal pressure in the foam mass when electric current energy is introduced into it

A concept has been put forward about the potential energy inherent in the nature of the foam system to self-compact under the complex action of an electrohydrothermal force field on it. The generation of excess internal pressure in the foam system was studied analytically and experimentally. Experimental data on monitoring the dynamics of temperature and pressure were obtained using a computer and a modern electronic component base. The method inherent in the technology allows combining a number of processes in one operation: compaction of the refractory components of the mixture, removal of shrinkage moisture, stamping of any profile of a lightweight product, providing clear edges that do not require grinding and trimming of products.

Evaluation of Excess Thermodynamic Parameters in a Binary Liquid Mixture (Cyclohexane +O-Xylene) at Different Temperatures

The ultrasonic velocity, density and viscosity in binary liquid mixture cyclohexane witho-xylene have been determined at different temperatures from 303.15 to 318.15 K over the whole composition range. The data have been utilized to estimate the excess adiabatic compressibility (βE), excess volumes (VE), excess intermolecular free length (LfE), excess internal pressure (πE) and excess enthalpy (HE) at the above temperatures. The excess values have been found to be useful in estimating the strength of the interactions in the liquid mixtures. Analysis of these parameters indicates that there are weak interactions among the components of the binary mixtures.

The impact of temperature change on stress deformed state of a main pipeline surrounded by a viscous medium and affected by thrusts and dislocations of the Earth’s crust

The present investigation concerns the movement and stress deformed state of a main pipeline with excess internal pressure surrounded by a highly viscous medium under changing temperature and also in the case of thrusts and dislocations of the Earth’s crust. Account is taken of constraint forces occurred due to excess internal pressure and temperature change.

Pressure and temperature dependence of the excess thermodynamic properties of binary dimethyl carbonate + n-octane mixtures

In this work we report several excess thermodynamic properties for the dimethyl carbonate + n-octane system in an effort to better understand their behavior over wide temperature and pressure ranges. From previous experimental pVTx data for this system, the changes in the excess molar Gibbs energies, in the excess molar entropies, and in the excess molar enthalpies due to pressure have been determined over a wide temperature range and for pressures up to 25 MPa. A correlation of the excess volume as a function of pressure was used for each composition and temperature, together with a new, recently proposed equation for the excess molar volume as a function of temperature, pressure, and composition. Excess molar enthalpies and excess molar Gibbs energies at 298.15 K and for pressures up to 25 MPa were calculated using literature data at atmospheric pressure. Furthermore, the excess isothermal compressibility, the excess isobaric expansivity, and the excess internal pressure were calculated. The expression for the internal pressure of an ideal mixture suggested recently by Marczak has been used.Key words: excess thermodynamic properties, dimethyl carbonate, n-octane, high pressure.

Solubility, enthalpy, and heat capacity of solution of tris(2,4-pentanedionato)cobalt(III) in aqueous mixed solvents of 2-butoxyethanol and 2-ethoxyethanol

The solubility in mole fraction Xs of tris(2,4-pentanedionato)cobalt(III) (Co(acac)3) in aqueous mixtures of 2-butoxyethanol (BE) and 2-ethoxyethanol (EE) has been determined over the temperature range 5–50 °C. From these data, the enthalpy [Formula: see text] and heat capacity of solution [Formula: see text] of Co(acac)3 are estimated by using the Clarke and Glew procedure. For the water–BE system, an approximately linear correlation is found between the excess enthalpy of solution [Formula: see text] of Co(acac)3 and the excess internal pressure δPi of the mixtures at 25 °C. This finding suggests that the composition dependence of [Formula: see text] in this system is mostly governed by the composition dependence of Pi. On the other hand, [Formula: see text] in these mixtures exhibits a characteristic composition dependence and its composition dependence in the water–BE mixtures may be qualitatively explained by considering an effect of the microphase transition which has been shown to occur in the mixture. The composition dependence of both [Formula: see text] and [Formula: see text] in the water–BE mixture is analogous to that in the water–BE mixture and this finding suggests that a microphase formation may also occur in the former mixture. Keywords: tris(2,4-pentanedionato)cobalt(III), temperature dependence of solubility, enthalpy and heat capacity of solution, aqueous mixtures of 2-butoxyethanol and 2-ethoxyethanol, microphase transition.

Enthalpy of solution of tris(2,4-pentanedionato)cobalt(III) in aqueous mixed solvents of 1,4-dioxane and 2-methyl-2-propanol

The solubilities Xs of tris(2,4-pentanedionato)cobalt(III) (Co(acac)3) in water – 1,4-dioxane (D) and water – 2-methyl-2-propanol (TBA) mixtures were determined over the temperature range of 15–60 °C and 20–43 °C, respectively. These data were fitted to [Formula: see text] and the enthalpy of solution [Formula: see text] of Co(acac)3 was estimated by differentiating the equation. For the water–D system, a linear correlation was found between the excess enthalpy of solution [Formula: see text] of Co(acac)3 and the excess internal pressure [Formula: see text] of the mixtures. [Formula: see text] of Co(acac)3 in the water–TBA mixtures showed complicated composition dependence due to microheterogeneity in the mixtures. The enthalpy of hydrophobic hydration [Formula: see text] of Co(acac)3 in the water–D mixtures was also estimated from the solubility curves and it was found that [Formula: see text] decreased exponentially with decreasing mole fraction of water.