scholarly journals Numerical implementation and oceanographic application of the Gibbs thermodynamic potential of seawater

2004 ◽  
Vol 1 (1) ◽  
pp. 1-19 ◽  
Author(s):  
R. Feistel
Keyword(s):  
Potential Function ◽  
Thermodynamic Potential ◽  
Temperature Scale ◽  
Chemical Potential ◽  
Pure Water ◽  
Potential Temperature ◽  
Visual Basic ◽  
Numerical Implementation ◽  
Gibbs Function ◽  
Potential Density

Abstract. The 2003 Gibbs thermodynamic potential function represents a very accurate, compact, consistent and comprehensive formulation of equilibrium properties of seawater. It is expressed in the International Temperature Scale ITS-90 and is fully consistent with the current scientific pure water standard, IAPWS-95. Source code examples in FORTRAN, C++ and Visual Basic are presented for the numerical implementation of the potential function and its partial derivatives, as well as for potential temperature. A collection of thermodynamic formulas and relations is given for possible applications in oceanography, from density and chemical potential over entropy and potential density to mixing heat and entropy production. For colligative properties like vapour pressure, freezing points, and for a Gibbs potential of sea ice, the equations relating the Gibbs function of seawater to those of vapour and ice are presented.

scholarly journals Numerical implementation and oceanographic application of the Gibbs thermodynamic potential of seawater

Ocean Science ◽  
2005 ◽  
Vol 1 (1) ◽  
pp. 9-16 ◽  
Author(s):  
R. Feistel
Keyword(s):  
Potential Function ◽  
Thermodynamic Potential ◽  
Temperature Scale ◽  
Chemical Potential ◽  
Pure Water ◽  
Potential Temperature ◽  
Visual Basic ◽  
Numerical Implementation ◽  
Gibbs Function ◽  
Potential Density

Abstract. The 2003 Gibbs thermodynamic potential function represents a very accurate, compact, consistent and comprehensive formulation of equilibrium properties of seawater. It is expressed in the International Temperature Scale ITS-90 and is fully consistent with the current scientific pure water standard, IAPWS-95. Source code examples in FORTRAN, C++ and Visual Basic are presented for the numerical implementation of the potential function and its partial derivatives, as well as for potential temperature. A collection of thermodynamic formulas and relations is given for possible applications in oceanography, from density and chemical potential over entropy and potential density to mixing heat and entropy production. For colligative properties like vapour pressure, freezing points, and for a Gibbs potential of sea ice, the equations relating the Gibbs function of seawater to those of vapour and ice are presented.

scholarly journals Numerical implementation and oceanographic application of the Gibbs potential of ice

Ocean Science ◽  
2005 ◽  
Vol 1 (1) ◽  
pp. 29-38 ◽  
Author(s):  
R. Feistel ◽  
W. Wagner ◽  
V. Tchijov ◽  
C. Guder
Keyword(s):  
Sea Ice ◽  
Temperature Scale ◽  
Pure Water ◽  
Gibbs Potential ◽  
Gibbs Function ◽  
Water Ice ◽  
Temperature And Pressure ◽  
Parameter Ranges ◽  
First Time ◽  
Thermodynamic Equations

Abstract. The 2004 Gibbs thermodynamic potential function of naturally abundant water ice is based on much more experimental data than its predecessors, is therefore significantly more accurate and reliable, and for the first time describes the entire temperature and pressure range of existence of this ice phase. It is expressed in the ITS-90 temperature scale and is consistent with the current scientific pure water standard, IAPWS-95, and the 2003 Gibbs potential of seawater. The combination of these formulations provides sublimation pressures, freezing points, and sea ice properties covering the parameter ranges of oceanographic interest. This paper provides source code examples in Visual Basic, Fortran and C++ for the computation of the Gibbs function of ice and its partial derivatives. It reports the most important related thermodynamic equations for ice and sea ice properties.

scholarly journals Numerical implementation and oceanographic application of the Gibbs potential of ice

2005 ◽  
Vol 2 (1) ◽  
pp. 37-61 ◽  
Author(s):  
R. Feistel ◽  
W. Wagner ◽  
V. Tchijov ◽  
C. Guder
Keyword(s):  
Sea Ice ◽  
Temperature Scale ◽  
Pure Water ◽  
Gibbs Potential ◽  
Gibbs Function ◽  
Water Ice ◽  
Temperature And Pressure ◽  
Parameter Ranges ◽  
First Time ◽  
Thermodynamic Equations

Abstract. The 2004 Gibbs thermodynamic potential function of naturally abundant water ice is based on much more experimental data than its predecessors, is therefore significantly more accurate and reliable, and for the first time describes the entire temperature and pressure range of existence of this ice phase. It is expressed in the ITS-90 temperature scale and is consistent with the current scientific pure water standard, IAPWS-95, and the 2003 Gibbs potential of seawater. The combination of these formulations provides sublimation pressures, freezing points, and sea ice properties covering the parameter ranges of oceanographic interest. This paper provides source code examples in Visual Basic, Fortran and C++ for the computation of the Gibbs function of ice and its partial derivatives. It reports the most important related thermodynamic equations for ice and sea ice properties.

Normal-Strain Induced Change in Lattice-Type for Confined Cyclohexane Films

1996 ◽  
Vol 464 ◽  
Author(s):  
J.E. Curry ◽  
J.H. Cushman
Keyword(s):  
Triangular Lattice ◽  
Chemical Potential ◽  
Potential Temperature ◽  
Computer Experiments ◽  
Square Lattice ◽  
Melting Transition ◽  
Normal Strain ◽  
Surface Forces Apparatus ◽  
Bulk Fluid ◽  
Lattice Type

ABSTRACTOne to three layer cyclohexane films confined between mica-like surfaces are studied to elucidate changes in the films' lattice-type. The laterally confined film is in equilibrium with the bulk fluid that is well into the liquid regime of its phase diagram. Monte Carlo simulations are conducted at constant chemical potential, temperature, and V=Ah, where A is the lateral area and h is the separation between the walls. One and two layers of fluid freeze as h increases. The one layer fluid has a triangular lattice, while the two layer fluid exhibits first a square lattice and then a triangular lattice with increasing surface separation. In contrast to previous studies, solidlike order is induced primarily by the strong fluid-solid interaction and is largely a function of pore width. A shift in the relative alignment of the surfaces perturbs the solidlike fluid structure but does not cause the sudden shear melting transition associated with epitaxial alignment of the fluid atoms with the surface. There is a correlation between the shear stress calculated in the computer experiments and that measured in Surface Forces Apparatus experiments.

Algorithms for Density, Potential Temperature, Conservative Temperature, and the Freezing Temperature of Seawater

2006 ◽  
Vol 23 (12) ◽  
pp. 1709-1728 ◽  
Author(s):  
David R. Jackett ◽  
Trevor J. McDougall ◽  
Rainer Feistel ◽  
Daniel G. Wright ◽  
Stephen M. Griffies
Keyword(s):  
Thermal Expansion ◽  
Equation Of State ◽  
Thermodynamic Potential ◽  
Potential Temperature ◽  
Inverse Function ◽  
Freezing Temperature ◽  
Ocean Models ◽  
The Difference ◽  
New Equation ◽  
Density Equation

Abstract Algorithms are presented for density, potential temperature, conservative temperature, and the freezing temperature of seawater. The algorithms for potential temperature and density (in terms of potential temperature) are updates to routines recently published by McDougall et al., while the algorithms involving conservative temperature and the freezing temperatures of seawater are new. The McDougall et al. algorithms were based on the thermodynamic potential of Feistel and Hagen; the algorithms in this study are all based on the “new extended Gibbs thermodynamic potential of seawater” of Feistel. The algorithm for the computation of density in terms of salinity, pressure, and conservative temperature produces errors in density and in the corresponding thermal expansion coefficient of the same order as errors for the density equation using potential temperature, both being twice as accurate as the International Equation of State when compared with Feistel’s new equation of state. An inverse function relating potential temperature to conservative temperature is also provided. The difference between practical salinity and absolute salinity is discussed, and it is shown that the present practice of essentially ignoring the difference between these two different salinities is unlikely to cause significant errors in ocean models.

scholarly journals Hydrography and Circulation West of Sardinia in June 2014

2017 ◽  
Author(s):  
Michaela Knoll ◽  
Ines Borrione ◽  
Heinz-Volker Fiekas ◽  
Andreas Funk ◽  
Michael P. Hemming ◽  
...  
Keyword(s):  
Eastern Mediterranean ◽  
Potential Temperature ◽  
Atlantic Water ◽  
Western Mediterranean ◽  
Anticyclonic Eddy ◽  
Intermediate Water ◽  
Potential Density ◽  
Sea Trial ◽  
The North

Abstract. In the mainframe of the REP14-MED sea trial in June 2014, the hydrography and circulation west of Sardinia, observed by means of gliders, shipborne CTD instruments, towed devices, and vessel-mounted ADCPs, are presented and compared with previous knowledge. So far, the circulation is not well known in this area, and the hydrography is subject to long-term changes. Potential temperature, salinity, and potential density ranges, as well as core values of the observed water masses were determined. Modified Atlantic Water (MAW), with potential density anomalies below 28.72 kg m−3, showed a salinity minimum of 37.93 at 50 dbar. Levantine Intermediate Water (LIW), with a salinity maximum of about 38.70 at 400 dbar, was observed within a range of 28.72 < σΘ [kg m−3] < 29.10. MAW and LIW showed slightly higher salinities than previous investigations. During the trial, LIW covered the whole area from the Sardinian shelf to 7°15' E. Only north of 40° N was it tied to the continental slope. Within the MAW, a cold and saline anticyclonic eddy was observed in the southern trial area. The strongest variability in temperature and salinity appeared around this eddy, and in the southwestern part of the domain, where unusually low saline surface water entered the area towards the end of the experiment. An anticyclonic eddy of Winter Intermediate Water was recorded moving northward at 0.014 m s−1. Geostrophic currents and water mass transports calculated across zonal and meridional transects showed a good agreement with vessel-mounted ADCP measurements. Within the MAW, northward currents were observed over the shelf and offshore, while a southward transport of about 1.5 Sv occurred over the slope. A net northward transport of 0.38 Sv across the southern transect decreased to zero in the north. Within the LIW, northward transport of 0.6 Sv across the southern transects were mainly observed offshore, and decreased to 0.3 Sv in the north where they were primarily located over the slope. This presentation of the REP14-MED observations helps to further understand the long-term evolution of hydrography and circulation in the Western Mediterranean, where considerable changes occurred after the Eastern Mediterranean Transient and the Western Mediterranean Transition.

scholarly journals Locating the critical end point using the linear sigma model coupled to quarks.

2018 ◽  
Vol 172 ◽  
pp. 02003
Author(s):  
Alejandro Ayala ◽  
J. A. Flores ◽  
L. A. Hernández ◽  
S. Hernández-Ortiz
Keyword(s):  
Sigma Model ◽  
Chemical Potential ◽  
Potential Temperature ◽  
Mean Field ◽  
Field Approximation ◽  
Baryon Density ◽  
Linear Sigma Model ◽  
Mean Field Approximation ◽  
End Point ◽  
The Mean

We use the linear sigma model coupled to quarks to compute the effective potential beyond the mean field approximation, including the contribution of the ring diagrams at finite temperature and baryon density. We determine the model couplings and use them to study the phase diagram in the baryon chemical potential-temperature plane and to locate the Critical End Point.

scholarly journals Hybrid stars from a three-flavor NJL model with two kinds of tensor condensates

2020 ◽  
Vol 29 (10) ◽  
pp. 2050093
Author(s):  
Masatoshi Morimoto ◽  
Yasuhiko Tsue ◽  
João da Providência ◽  
Constança Providência ◽  
Masatoshi Yamamura
Keyword(s):  
Equation Of State ◽  
Quark Matter ◽  
Thermodynamic Potential ◽  
Chemical Potential ◽  
Point Interaction ◽  
Condensed Phases ◽  
Charge Neutrality ◽  
Njl Model ◽  
Hybrid Stars ◽  
The Relationship

To obtain the equation of state of quark matter and construct hybrid stars, we calculate the thermodynamic potential in the three-flavor Nambu–Jona-Lasinio model including the tensor-type four-point interaction and the Kobayashi–Maskawa–’t Hooft interaction. To construct the hybrid stars, it is necessary to impose the [Formula: see text] equilibrium and charge neutrality conditions on the system. It is shown that tensor condensed phases appear at large chemical potential. Under the possibility of the existence of the tensor condensates, the relationship between the radius and mass of hybrid stars is estimated.

scholarly journals On the Question of the Problems of Statistical Calculations of the Conducting Crystals Thermodynamic and Kinetic Properties

2019 ◽  
Vol 20 (4) ◽  
pp. 345-353
Author(s):  
Ya.S. Budzhak ◽  
T. Wacławski
Keyword(s):  
Equilibrium State ◽  
Thermodynamic Equilibrium ◽  
Thermodynamic Potential ◽  
Chemical Potential ◽  
Thermodynamic Characteristics ◽  
Kinetic Properties ◽  
Elementary Model ◽  
Dispersion Law ◽  
Thermodynamic Equilibrium State

This paper presents an elementary model of a crystal and its thermodynamic equilibrium state. It was shown that the thermodynamic characteristics of the crystal at this state are described by the Gibbs grand thermodynamic potential. If the crystal is removed away from the equilibrium state, then in this state it will be described by the set of kinetic properties, and these properties are statistically calculated with the use of the non-equilibrium Gibbs grand thermodynamic potential. Crystals’ thermodynamic and kinetic properties have analytical dependence on the current carriers dispersion law and chemical potential of these carriers. In this work, it was shown that the determination of the dispersion law and chemical potential – these are complicated problems of statistical and kinetic theories of crystals’ properties.

Roles of colloidal molecules in Starling's hypothesis and in returning interstitial fluid to the vasa recta

1995 ◽  
Vol 268 (5) ◽  
pp. H2133-H2144 ◽  
Author(s):  
H. T. Hammel
Keyword(s):  
Aqueous Solution ◽  
Interstitial Fluid ◽  
Chemical Potential ◽  
Pure Water ◽  
External Pressure ◽  
Capillary Endothelium ◽  
Free Fluid ◽  
Vasa Recta ◽  
Simple Question

To begin to understand the role of colloidal molecules, a simple question requires an answer: How do the solutes alter water in an aqueous solution? Hulett's answer deserves attention, namely, the water in the solution at temperature and external pressure applied to solution (T,pe1) is altered in the same way that pure water is altered by reducing the pressure applied to it by the osmotic pressure of the water at a free surface of the solution. It is nonsense to relate the lower chemical potential of water in a solution to a lower fugacity or to a lower activity of the water in the solution, since these terms have no physical meaning. It is also incorrect to attribute the lower chemical potential of the water to a lower concentration of water in the solution. Both claims are derived from the teachings of G. N. Lewis and are erroneous. Textbook accounts of the flux of fluid to and from capillaries in the kidney and other tissues are inadequate, if not in error, as they are based on these bogus claims. An understanding of the process by which colloidal proteins in plasma affect the flux of nearly protein-free fluid across the capillary endothelium must start with insights derived from the teachings of G. Hulett and H. Dixon. The main points are 1) colloidal molecules can exert a pressure against a membrane that reflects them and, thereby, displace a distensible membrane; 2) they can alter the internal tension of the fluid through which they diffuse when there is a concentration gradient of the molecules; and 3) only by these means can they influence the flux of plasma fluid across the capillary endothelium. However, the process is complex, since both the hydrostatic pressure and protein concentrations of fluids inside and outside the capillary vary with both position and time as plasma flows through the capillary.

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