scholarly journals Two-phase equilibrium states in individual Cu–Ni nanoparticles: size, depletion and hysteresis effects

2015 ◽  
Vol 6 ◽  
pp. 1811-1820 ◽  
Author(s):  
Aram S Shirinyan
Keyword(s):  
Phase Diagram ◽  
Phase Transformation ◽  
Phase Equilibrium ◽  
Size Effects ◽  
Solubility Diagram ◽  
Two Phase ◽  
Nanoscale Systems ◽  
First Order ◽  
Size Dependent ◽  
First Order Phase

In isolated bimetallic nanoscale systems the limit amount of matter and surface-induced size effects can change the thermodynamics of first-order phase transformation. In this paper we present theoretical modification of Gibbs free energy concept describing first-order phase transformation of binary alloyed nanoparticles taking into account size effects as well as depletion and hysteresis effects. In such a way the hysteresis in a form of nonsymmetry for forth and back transforming paths takes place; compositional splitting and the loops-like splitted path on the size dependent temperature–composition phase diagram occur. Our calculations for individual Cu–Ni nanoparticle show that one must differentiate the solubility curves and the equilibrium loops (discussed here in term of solidification and melting loops). For the first time we have calculated and present here on the temperature–composition phase diagram the nanomelting loop at the size of 80 nm and the nanosolidification loop at the size of 25 nm for an individual Cu–Ni nanoparticle. So we observe the difference between the size-dependent phase diagram and solubility diagram, between two-phase equilibrium curves and solubility curves; also intersection of nanoliquidus and nanosolidus is available. These findings lead to the necessity to reconsider such basic concepts in materials science as phase diagram and solubility diagram.

scholarly journals Electric properties of olive oil under pressure

2021 ◽  
Author(s):  
L. T. Pawlicki ◽  
R. M. Siegoczyński ◽  
S. Ptasznik ◽  
K. Marszałek
Keyword(s):  
Molecular Structure ◽  
Phase Transition ◽  
Phase Diagram ◽  
Phase Transitions ◽  
Olive Oil ◽  
Material Parameters ◽  
First Order ◽  
Long Time ◽  
Capacitive Reactance ◽  
First Order Phase

AbstractThe main purpose of the experiment was a thermodynamic research with use of the electric methods chosen. The substance examined was olive oil. The paper presents the resistance, capacitive reactance, relative permittivity and resistivity of olive. Compression was applied with two mean velocities up to 450 MPa. The results were shown as functions of pressure and time and depicted on the impedance phase diagram. The three first order phase transitions have been detected. All the changes in material parameters were observed during phase transitions. The material parameters measured turned out to be the much more sensitive long-time phase transition factors than temperature. The values of material parameters and their dependence on pressure and time were compared with the molecular structure, arrangement of molecules and interactions between them. Knowledge about olive oil parameters change with pressure and its phase transitions is very important for olive oil production and conservation.

Thermodynamic properties of a spin-1 model with long-range interactions

2018 ◽  
Vol 32 (05) ◽  
pp. 1850053 ◽  
Author(s):  
Ji-Xuan Hou ◽  
Xu-Chen Yu
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Phase Diagram ◽  
Long Range ◽  
Order Phase Transition ◽  
First Order ◽  
First Order Phase Transition ◽  
Long Range Interactions ◽  
External Magnetic Field Strength ◽  
First Order Phase

The long-range interacting spin-1 chain placed in a staggered magnetic field is studied by means of microcanonical approach. Firstly, we study the microcanonical entropy of the system in the thermodynamic limit and find the system is non-ergodic and can exhibit either first-order phase transition or second-order phase transition by shifting the external magnetic field strength. Secondly, we construct the global phase diagram of the system and find a phase transition area in the phase diagram corresponding to the temperature jump of the first-order phase transition.

scholarly journals On the Impossibility of First-Order Phase Transitions in Systems Modeled by the Full Euler Equations

Entropy ◽  
2019 ◽  
Vol 21 (11) ◽  
pp. 1039
Author(s):  
Maren Hantke ◽  
Ferdinand Thein
Keyword(s):  
Euler Equations ◽  
Single Phase ◽  
Two Phase Flows ◽  
Two Phase ◽  
First Order ◽  
Engineering Sciences ◽  
The One ◽  
First Order Phase ◽  
Isothermal Euler Equations ◽  
Appl Math

Liquid–vapor flows exhibiting phase transition, including phase creation in single-phase flows, are of high interest in mathematics, as well as in the engineering sciences. In two preceding articles the authors showed on the one hand the capability of the isothermal Euler equations to describe such phenomena (Hantke and Thein, arXiv, 2017, arXiv:1703.09431). On the other hand they proved the nonexistence of certain phase creation phenomena in flows governed by the full system of Euler equations, see Hantke and Thein, Quart. Appl. Math. 2015, 73, 575–591. In this note, the authors close the gap for two-phase flows by showing that the two-phase flows considered are not possible when the flow is governed by the full Euler equations, together with the regular Rankine-Hugoniot conditions. The arguments rely on the fact that for (regular) fluids, the differences of the entropy and the enthalpy between the liquid and the vapor phase of a single substance have a strict sign below the critical point.

First-order phase diagram of thiourea and raman spectroscopy

1975 ◽  
Vol 33 (1) ◽  
pp. 99-103 ◽  
Author(s):  
Pierre Figuiere ◽  
Michel Ghelfenstein ◽  
Henri Szwarc
Keyword(s):  
Phase Diagram ◽  
Raman Spectroscopy ◽  
First Order ◽  
First Order Phase

Calculation and Plot of Predominance Area Phase Diagram for Cu-S-O Ternary System

2012 ◽  
Vol 503-504 ◽  
pp. 390-395
Author(s):  
Shang Yong Li ◽  
Yuan Hu ◽  
Gang Xie ◽  
Jun Han Li
Keyword(s):  
Phase Diagram ◽  
Phase Equilibrium ◽  
Physical Properties ◽  
Chemical Reactions ◽  
Phase Point ◽  
Two Phase ◽  
Clear Physical Meaning ◽  
Three Phase ◽  
Calculated Model ◽  
Phase Equilibrium Line

The typical chemical reactions of metal were analyzed in this paper, and the two-phase equilibrium line calculated model was obtained. By use of the physical properties database, the design of chemical reactions and the compounds were to be determined. Through the calculating the two-phase point and three-phase point ,the predominance area phase diagram algorithm based on the physical properties database was formed, which has clear physical meaning and accuracy calculation result, and also whose result was consistent with that of the literature.

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