THE THERMODYNAMIC PROPERTIES AND PHASE DIAGRAM OF THE GOLD–CADMIUM SYSTEM BY THE ISOPIESTIC METHOD

1965 ◽  
Vol 43 (8) ◽  
pp. 2319-2327 ◽  
Author(s):  
L. J. Bartha ◽  
W. A. Alexander
Keyword(s):  
Phase Diagram ◽  
Free Energy ◽  
Phase Region ◽  
Isopiestic Method ◽  
Partial Molar Free Energy ◽  
Gold Alloys ◽  
Heat Of Solution ◽  
Molar Free Energy ◽  
Phase Boundaries ◽  
Two Phase

Activities of cadmium in gold alloys with up to 50 atom % Cd have been determined by an isopiestic method. The partial molar free energy, entropy, and heat of solution in the alpha and beta phases are calculated between 500 and 600 °C. The phase boundaries have been observed between 16 and 60 atom % above 400 °C. The boundaries of the two-phase regions α2 + β and β + δ′ are found at somewhat different concentrations than before, but the two-phase region α + α2 was not observed.

Rheological and structural studies on heat-induced gelation of concentrated skim milk

1995 ◽  
Vol 62 (2) ◽  
pp. 257-267 ◽  
Author(s):  
Atsumi Tobitani ◽  
Haruyoshi Yamamoto ◽  
Toshiaki Shioya ◽  
Simon B. Ross-Murphy
Keyword(s):  
Phase Diagram ◽  
Laser Light ◽  
Skim Milk ◽  
Phase Region ◽  
Polymer Physics ◽  
Phase Behaviour ◽  
Two Phase ◽  
Effects Of Ph ◽  
Higher Temperature ◽  
Temperature Side

SUMMARYHeat-induced gelation of milk was studied using both rheological and structural techniques. The sample was a conventional skim milk, concentrated with an ultrafiltration membrane, which formed gels when heated at appropriate pH. We investigated some factors that are considered to affect the gelation, such as concentration, pH and rennet treatment. The gelation process was monitored with a high precision oscillatory shear rheometer and the structure of gels was evaluated with quasi-elastic laser light scattering. From these results the gelation and phase separation behaviour were determined. By combining the results for different concentrations a phase diagram was obtained, which indicated that skim milk had a two-phase region on the higher temperature side. The effects of pH and rennet treatment were also evaluated with the aid of this phase diagram. The results were discussed on the basis of concepts of the phase behaviour of polymers, which were successfully developed in polymer physics.

Two-Phase Microstructures Formed by Phase-Separation of Coherent Precipitates in Elastically Constrained Alloy Systems

2010 ◽  
Vol 638-642 ◽  
pp. 2215-2220 ◽  
Author(s):  
Minoru Doi
Keyword(s):  
Free Energy ◽  
Phase Separation ◽  
Surface Energy ◽  
Phase Region ◽  
Precipitate Phase ◽  
Two Phase ◽  
Phase Separations ◽  
Chemical Free Energy ◽  
Elastic Constraint ◽  
Alloy Systems

Coherent two-phase microstructures consisting of ordered precipitate and disordered matrix phases sometimes exhibit a phase-separation, which brings the split and/or the decelerated coarsening of precipitates. When the coherent two-phase microstructure of A1+L12 (+’) in Ni-base alloys are aged inside the two-phase region of A1+L12 , the L12 precipitate sometimes exhibit a phase-separation and A1 phase newly appears and grows in each L12 precipitate. Phase-separations of the same type to the above also take place due to ageing of coherent two-phase microstructures of A2+D03 and A2+B2 in Fe-base alloys: D03 and B2 precipitates sometimes exhibit phase-separations and A2 phase newly appears and grows in both precipitates. These types of phase-separation take place under the influence of chemical free energy. In the course of further ageing, the new disordered phases of A1 and A2 change their morphology in various ways depending on the elastic constraint: i.e. the morphology of new A1 or A2 phase is influenced by the elastic energies and the surface energy.

Phase evolution during crystallization of nanocomposite alloys with Co:Fe ratios in the two-phase region of the binary Fe–Co phase diagram

2007 ◽  
Vol 101 (9) ◽  
pp. 09N108 ◽  
Author(s):  
P. R. Ohodnicki ◽  
S. Y. Park ◽  
H. K. McWilliams ◽  
K. Ramos ◽  
D. E. Laughlin ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Phase Evolution ◽  
Phase Region ◽  
Two Phase

scholarly journals Ternary Phase Diagram of Model Dentin Adhesive Exposed to Over-wet Environments

2011 ◽  
Vol 90 (12) ◽  
pp. 1434-1438 ◽  
Author(s):  
Q. Ye ◽  
J. Park ◽  
J.S. Laurence ◽  
R. Parthasarathy ◽  
A. Misra ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Ternary Phase Diagram ◽  
Water System ◽  
Phase Region ◽  
Partial Phase Diagram ◽  
Conjugate Pair ◽  
Two Phase ◽  
Phase Partitioning ◽  
Equilibrium Partition ◽  
Tie Lines

When adhesives and/or composites are bonded to the tooth, water in the environment can interfere with proper interface formation. Formation of water blisters and phase separation at the adhesive/dentin interface have appeared as new types of bond defects. To better understand this problem, we determined the near-equilibrium partition of the hydrophobic/hydrophilic components when exposed to over-wet environments. Model methacrylate-based adhesives were mixed with different amounts of water to yield well-separated aqueous and resin phases. It was found that less than 0.1% BisGMA but nearly one-third of the HEMA diffused into the aqueous phase, leaving the remaining resin phase relatively hydrophobic. A partial phase diagram was created for the ternary BisGMA/HEMA/water system. All the experimental phase partitioning data were plotted, and the points lay on a binodal curve that separated the single-phase region from the two-phase region. We obtained the 3 tie lines by connecting the 2 points of each conjugate pair of the phase partitioning data from the 3 sets of tripartite mixtures. Information about solubility, water miscibility, distribution ratio, and phase partitioning behavior could be obtained quantitatively. This type of phase diagram will provide a more thorough understanding of current adhesive performance and elucidate directions for further improvement.

Phase Relationships in Chemical Flooding

1978 ◽  
Vol 18 (05) ◽  
pp. 325-338 ◽  
Author(s):  
R.C. Nelson ◽  
G.A. Pope
Keyword(s):  
Phase Diagram ◽  
Phase Equilibrium ◽  
Phase Diagrams ◽  
Single Phase ◽  
Phase Region ◽  
Chemical Flooding ◽  
Two Phase ◽  
Equilibrium Phases ◽  
Flow Experiments ◽  
Diagram Representation

Abstract Results of laboratory chemical floods are presented to show that equilibrium phases observed presented to show that equilibrium phases observed in test tubes are representative of phases produced in core flow experiments. Consequently, many performance characteristics of chemical floods can performance characteristics of chemical floods can be explained and predicted from equilibrium surfactant-brine-oil phase diagrams. An oil reservoir under chemical flooding can be visualized as a series of connected cells with phase equilibrium attained in each. Fluid flow from phase equilibrium attained in each. Fluid flow from one cell to the next is governed, not so much by initial properties of the oil, brine, or chemical slug and drive, as by properties of equilibrium phases formed from those fluids. Three types of equilibrium phase environment are defined. Results of interfacial tension measurements and laboratory flow experiments indicate that chemical floods should be designed to keep as much surfactant as possible for as long as possible in the "Type III" phase environment while the surfactant is traversing the reservoir. Introduction Recent research shows that when certain surfactants of interest in chemical flooding are equilibrated with brine and oil, the phases formed can be represented by relatively simple triangular phase diagrams. Furthermore, Healy and Reed phase diagrams. Furthermore, Healy and Reed revealed that surfactant-rich equilibrium phases, while immiscible with brine and oil, can displace waterflood residual oil effectively. Other papers involving phases of chemical flooding systems have appeared subsequently. This paper extends the use of phase diagrams in chemical flooding research by presenting laboratory evidence that the same phases, observed when surfactant, brine, and oil are equilibrated in sample tubes, form and transport in a core under a chemical flood. This interrelationship between surfactant-brine-oil phase behavior and the characteristics of chemical flooding is reminiscent of the interrelationship between alcohol-brine-oil phase behavior and the characteristics of alcohol flooding as described by Tabor et al. We discuss here some consequences of local phase equilibrium in an oil reservoir under a chemical flood. First, we review briefly the phase diagram representation. Next, visualizing the core as a series of connected mixing cells in each cell of which phase equilibrium is attained, we prescribe conditions for effluent liquids, based on phase diagrams for surfactant-brine-oil systems. Then, we compare results of flow experiments with those prescribed conditions. prescribed conditions. PHASE DIAGRAM REPRESENTATION PHASE DIAGRAM REPRESENTATION Following Healy et al., Fig. 1 illustrates three types of generalized phase diagram for three quasi-single components - surfactant, brine, and oil. These phase diagrams represent what we define as "phase environments." A surfactant-brine-oil system in any of the three phase-environment types can equilibrate as a single phase or as multiple phases, depending on the over-all composition of phases, depending on the over-all composition of the system. At high-surfactant concentrations, all phase environments ideally are single phase. At lower-surfactant concentrations in a Type II(-) phase environment, two equilibrium phases are phase environment, two equilibrium phases are present. As indicated by the tielines in the present. As indicated by the tielines in the two-phase region, one phase is essentially pure oil and the other is a homogeneous phase containing surfactant, brine, and oil. Here, we shall call such a phase a "microemulsion." We use this term only to describe a phase containing surfactant, brine, and oil apparently in thermodynamic equilibrium with one or more other phases. The term does not suggest a particular concept regarding the structure of that phase. Thus, in a Type II(-) phase environment, the maximum number of equilibrium phases is two. When surfactant, brine, and oil are plotted as in Fig. 1, the tielines in the two-phase region have a negative slope; hence the "II(-)" designation. SPEJ P. 325

scholarly journals Statistical mechanics of binary systems

1942 ◽  
Vol 179 (978) ◽  
pp. 340-361 ◽  
Keyword(s):  
Phase Transition ◽  
Solid Solution ◽  
Partition Function ◽  
Binary Systems ◽  
Binary Solution ◽  
Phase Region ◽  
Atomic Fraction ◽  
Phase Boundaries ◽  
Binary Solid Solution ◽  
Two Phase

Mayer’s method for the expansion of the partition function of a gas is adapted to the calculation of the partition function of a binary solid solution. The partition function is expanded in powers of the atomic fraction. Singularities in this expansion correspond to a phase transition. The singularity can be calculated in the simplest case of a binary solution with a two-phase region. This case is treated in full; the limits of solubility and the specific heat are obtained. The latter is discontinuous at the phase boundaries.

Ab INITIO CALCULATION OF THE LixCoO2 PHASE DIAGRAM

1997 ◽  
Vol 496 ◽  
Author(s):  
Anton Van Der Ven ◽  
Mehmet K Aydinol ◽  
Gerbrand Ceder
Keyword(s):  
Phase Diagram ◽  
First Principles ◽  
Driving Forces ◽  
Intercalation Compound ◽  
Phase Region ◽  
Metal Insulator Transition ◽  
Two Phase ◽  
Metal Insulator ◽  
The Past ◽  
Li Batteries

ABSTRACTThe electrochemical properties of the layered intercalation compound LiCoO2 used as a cathode in Li batteries have been investigated extensively in the past 15 years. Despite this research, little is known about the nature and thermodynamic driving forces for the phase transformations that occur as the Li concentration is varied. In this work, the phase diagram of LixCoO2 is calculated from first principles for x ranging from 0 to 1. Our calculations indicate that there is a tendency for Li ordering at x = 1/2 in agreement with experiment [1]. At low Li concentration, we find that a staged compound is stable in which the Li ions selectively segregate to every other Li plane leaving the remaining Li planes vacant. We find that the two phase region observed at high Li concentration is not due to Li ordering and speculate that it is driven by a metal-insulator transition which occurs at concentrations slightly below x < 1.

Effect of Partial Thermal Cycles on Non-Chemical Free Energy Contributions in Polycrystalline Cu-Al-Be Shape Memory Alloy

2013 ◽  
Vol 738-739 ◽  
pp. 38-45
Author(s):  
Lajos Daróczi ◽  
Tarek El Rasasi ◽  
Dezső L. Beke
Keyword(s):  
Free Energy ◽  
Local Equilibrium ◽  
Hysteresis Loops ◽  
Martensitic Transformations ◽  
Phase Region ◽  
Maximum Temperature ◽  
Two Phase ◽  
A Value ◽  
Chemical Free Energy ◽  
Thermoelastic Transformation

Abstract. Thermoelasic martensitic transformations are controlled by the local equilibrium of chemical and non-chemical free energy contributions (D and E being the dissipative and elastic energies, respectively). The derivatives of non-chemical free energies ( ) as a function of the transformed martensite fraction (ξ) can be expressed from the experimental data obtained from the temperature-elongation, temperature-resistance, etc hysteresis loops. This method, developed in our laboratory, was used for the investigation of non complete, partial thermoelastic transformation cycles. In the first set of experiments the subsequent cycles were started below the Mf temperature and the maximum temperature was decreased gradually from a value above Af (series U). In the second (L) set the cycles were started above the Af and the minimum temperature was gradually increased from a value below Mf. In the third (UL) set the minor loops were positioned into the centre of the two phase region (i.e. the cycling was made with an increasing T temperature interval with T0.5 and <0.5, respectively. On the other hand the d() functions show a maximum at about the central point of the sub-cycles, and deviate considerably from the d() function obtained from the full cycles. This is also reflected in the  dependence of the integral value of the dissipative energy, D(): its value for the partial loops is lower than the dissipative energy calculated from the full cycle for the same transformed fraction interval. An opposite tendency (i.e. higher values for the partial loops) was obtained for the integral value of the elastic energy, E. The relative values of the dissipated energies, D, (calculated from the areas of the minor loops and normalized to the area of the major loop) are not very sensitive to the details of the cycling process, i.e. they are very similar for all sets.

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