Internal pressure of a thermodynamically ideal mixture and the excess internal pressure

2002 ◽  
Vol 4 (10) ◽  
pp. 1889-1890 ◽  
Author(s):  
Wojciech Marczak
2006 ◽  
Vol 124 (1-3) ◽  
pp. 121-123 ◽  
Author(s):  
Ranjan Dey ◽  
A.K. Singh ◽  
J.D. Pandey

2006 ◽  
Vol 4 ◽  
pp. 32-40
Author(s):  
M.I. Davletov ◽  
Yu.V. Kazantsev ◽  
A.G. Khakimov

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.


1987 ◽  
Vol 65 (6) ◽  
pp. 1218-1223 ◽  
Author(s):  
Yasuki Yoshimura

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.


Author(s):  
V. N. Sokov

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.


1976 ◽  
Vol 54 (3) ◽  
pp. 386-391 ◽  
Author(s):  
John H. Gee ◽  
Phyllis A. Gee

Of 23 species (nine families) of Central American fishes examined, nine (eight physostomes, one physoclist) did not reduce buoyancy by decreasing swim-bladder volume when current was encountered. The remainder (six physostomes, eight physoclists) decreased buoyancy, usually within 24–48 h, but three of these species (one physostome) were unable to maintain a reduced buoyancy for as long as 72 h once the minimum was achieved. All species have an excess internal pressure of swim-bladder gas. All of the North American species that have been studied do show a buoyancy alteration in response to changes in water current and adjust to a greater extent, although rates of adjustment appear similar to those of Central American fishes. Differences in flow regime between North and Central American streams are described and may partially account for these differences in reaction to water current.


1974 ◽  
Vol 31 (6) ◽  
pp. 1139-1141 ◽  
Author(s):  
John H. Gee ◽  
Kazimierz Machniak ◽  
Sandra M. Chalanchuk

All 12 species of physostomes and 8 species of physoclists altered their buoyancy in response to a change in water velocity. All species showed excess internal pressure of swimbladder gases.


1959 ◽  
Vol 36 (2) ◽  
pp. 315-332 ◽  
Author(s):  
R. MCN. ALEXANDER

1. A method is described whereby certain physical properties of the swimbladder have been determined in intact, unoperated Cypriniformes. These properties are volume, excess internal pressure, extensibility, and relative sensitivity (an index of the rate of change of volume with depth). 2. The mean volume of the swimbladder varies in the twelve species examined from 5.8 to 9.9 ml./100 g. body weight. 3. In most Cyprinidae the swimbladder gases are maintained at a mean pressure 2-3 cm. Hg above that of the surrounding water at the depth to which the fish is adapted. Higher pressures occur in a few species, most notably the bream (10.8 cm. Hg). A much lower pressure is found in Amiurus. An excess internal pressure is probably necessary to provide a taut swimbladder wall to operate Weberian ossicles. 4. The swimbladder wall has non-linear elastic properties such that as the excess pressure in the swimbladder rises the extensibility of its wall falls. The swimbladder also shows slow-elastic properties. The significance of these properties is discussed. 5. Excess internal pressure and low extensibility combine to limit the rate at which the volume of the swimbladder, and so the buoyancy of the fish, changes with depth. For small depth changes the swimbladder of the bream (an extreme case) changes its volume only one-quarter as much as would a free air-bubble.


2003 ◽  
Vol 81 (7) ◽  
pp. 840-849 ◽  
Author(s):  
Luis Lugo ◽  
María JP Comuñas ◽  
Enriqueta R López ◽  
Josefa García ◽  
Josefa Fernández

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.


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