scholarly journals To the Methodology of Phase Transition Temperature Determination in Aqueous Solutions of Thermo-Sensitive Polymers

2020 ◽  
Vol 22 (2) ◽  
pp. 129
Author(s):  
G.A. Mun ◽  
I. Moldakhan ◽  
S.B. Kabdushev ◽  
B.B. Yermukhambetova ◽  
R. Shaikhutdinov ◽  
...  
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Transition Temperature ◽  
Aqueous Solutions ◽  
Temperature Interval ◽  
Phase State ◽  
Transition Process ◽  
Phase Portraits ◽  
Quantitative Parameter ◽  
Phase Transition Process

An advanced methodology of phase transition determination in aqueous solutions of thermo-sensitive polymers by using of the phase portraits method has been suggested. The methodology allows highly accurate determining the temperature when exactly a half of molecules loses solubility (from the maximum number that can go to another phase state under given conditions). It is shown that since phase transition passes usually in a wide enough temperature interval this indicator should be used as a quantitative parameter that characterizes phase transition process. Additionally the suggested methodology allows introducing one more quantitative parameter that reflects a sharpness of phase transition. The methodology is verified by an example of phase transitions study in aqueous solutions of thermo-sensitive copolymers based on N-vinylpyrrolidone and vinyl propyl ether.

The structural phase transition process of free-standing monoclinic vanadium dioxide micron-sized rods: temperature-dependent Raman study

RSC Advances ◽  
2015 ◽  
Vol 5 (101) ◽  
pp. 83139-83143 ◽  
Author(s):  
Huafang Zhang ◽  
Quanjun Li ◽  
Pengfei Shen ◽  
Qing Dong ◽  
Bo Liu ◽  
...  
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Vanadium Dioxide ◽  
Structural Phase ◽  
Transition Process ◽  
Temperature Dependent ◽  
Free Standing ◽  
Lower Phase ◽  
Phase Transition Process ◽  
Raman Study

Micro-sized rods show a lower phase transition temperature than nano-sized rods, and this is interpreted on the basis of nucleating defects.

Thermodynamics of solution of gypsum and anhydrite in water over a wide temperature range

1984 ◽  
Vol 62 (3) ◽  
pp. 484-488 ◽  
Author(s):  
Horacio R. Corti ◽  
Roberto Fernandez-Prini
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
Transition Temperature ◽  
Thermodynamic Properties ◽  
Transition Process ◽  
Calcium Sulphate ◽  
Phase Transition Process ◽  
Different Temperatures ◽  
Pure Phases ◽  
Constant Charge

The solubility of calcium sulphate in water at different temperatures is important for the description of chemical processes occurring in heat exchangers as well as in geothermal processes. Great discrepancies have been reported between experimental and predicted solubilities at high temperature and the transition temperature for the phase transition process (gypsum → anhydrite) is ill-defined.We have analyzed the available data for the solubility of calcium sulphate in water with no added electrolyte. Ion-pairing has been taken into account to calculate the standard thermodynamic properties of the solution process.It is found that the solubility data for gypsum and anhydrite are thermodynamically very consistent. It is possible to obtain the thermodynamic properties of the phase transition from solution data and, at 298.15 K and 101.325 kPa, they are in very good agreement with reported values from measurements with the pure phases. The transition temperature is calculated to be 315.7 ± 0.4 K.It is also shown that the experimental data agree with values predicted for high temperature by employing well-established methods of calculation of solution thermodynamic properties (e.g., principles of correspondence and of constant charge).

Various types of holographic metal/superconductor phase transitions with dark matter sector

2016 ◽  
Vol 26 (06) ◽  
pp. 1750046
Author(s):  
Yan Peng ◽  
Tao Chen ◽  
Guohua Liu ◽  
Pengwei Ma
Keyword(s):  
Phase Transition ◽  
Black Hole ◽  
Dark Matter ◽  
Phase Transitions ◽  
Transition Temperature ◽  
De Sitter ◽  
Holographic Superconductor ◽  
Black Hole Background ◽  
Critical Phase ◽  
Matter Sector

We generalize the holographic superconductor model with dark matter sector by including the Stückelberg mechanism in the four-dimensional anti-de Sitter (AdS) black hole background away from the probe limit. We study effects of the dark matter sector on the [Formula: see text]-wave scalar condensation and find that the dark matter sector affects the critical phase transition temperature and also the order of phase transitions. At last, we conclude that the dark matter sector brings richer physics in this general metal/superconductor system.

The effect of Argon pressure dependent V thin film on the phase transition process of (020) VO2 thin film

2018 ◽  
Vol 427 ◽  
pp. 304-311 ◽  
Author(s):  
Yifan Meng ◽  
Kang Huang ◽  
Zhou Tang ◽  
Xiaofeng Xu ◽  
Zhiyong Tan ◽  
...  
Keyword(s):  
Thin Film ◽  
Phase Transition ◽  
Transition Process ◽  
Argon Pressure ◽  
Phase Transition Process

Exploration of Doubly Thermal Phase Transition Process of PDEGA-b-PDMA-b-PVCL in Water

Langmuir ◽  
2016 ◽  
Vol 32 (26) ◽  
pp. 6691-6700 ◽  
Author(s):  
Zhangxin Ye ◽  
Youcheng Li ◽  
Zesheng An ◽  
Peiyi Wu
Keyword(s):  
Phase Transition ◽  
Transition Process ◽  
Thermal Phase Transition ◽  
Phase Transition Process ◽  
Thermal Phase

A New Lattice Boltzmann Model for Phase Transition Process

2009 ◽  
Author(s):  
Longjian Li ◽  
Jianbang Zeng ◽  
Quan Liao ◽  
Wenzhi Cui
Keyword(s):  
Phase Transition ◽  
Lattice Boltzmann ◽  
Equations Of State ◽  
Density Ratio ◽  
Transition Process ◽  
Lattice Boltzmann Model ◽  
New Model ◽  
Phase Transition Process ◽  
Simulation Results ◽  
Boltzmann Model

A new lattice Boltzmann model, which is based on Shan-Chen (SC) model, is proposed to describe liquid-vapor phase transitions. The new model is validated through simulation of the one-component phase transition process. Compared with the simulation results of van der Waals fluid and the Maxwell equal-area construction, the results of new model are closer to the analytical solutions than those of SC model and Zhang model. Since the range of temperature and the maximum density ratio are increased, and the value of maximum spurious current is between those of SC and Zhang models, it is believed that this new model has better stability than SC and Zhang models. Therefore, the application scope of this new model is expanded. According to the principle of corresponding states in Engineering Thermodynamics, the simulations of water and ammonia phase transition process are implemented by using this new model with different equations of state. Compared to the experimental data of water and ammonia, the results show that the Peng-Robinson equation of state is more suitable to describe the water, ammonia and other substances phase transition process. Therefore, these simulation results have great significance for the real engineering applications.

scholarly journals The Effect of Selected Anions on Dipalmitoylphosphatidylcholine Phase Transitions

2002 ◽  
Vol 57 (7-8) ◽  
pp. 712-716 ◽  
Author(s):  
Adriana Przyczyna ◽  
Bożenna Różycka-Roszk ◽  
Marek Langner
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Transition Temperature ◽  
Phase Transition Temperature ◽  
Salt Concentration ◽  
Half Width ◽  
Main Phase ◽  
Interface Properties ◽  
Transition Enthalpy ◽  
Peak Half Width

The effect of three anions, Cl-, Br- and I-, on the phase transitions of dipalmitoylphosphatidylcholine (DPPC) was measured. Main phase transition was modestly affected by these anions in the salt concentration range 0.2 M. For Cl- and Br- the temperature of main phase transition was lower (by about 0.5 °C), its half-width modestly larger and enthalpy practically unchanged, all three parameters were altered to a much larger degree. Main phase transition temperature was 1.5 °C lower and the peak half-width significantly smaller. These changes were not accompanied by any alteration in main phase transition enthalpy. Iodide shifted the pretransition temperature toward lower values and increased its half-width to such an extent that at concentrations above 100 mm it was practically undetectable. Besides cations, the presence of anions also has a distinct effect on lipid bilayer interface properties.

CROSSOVER FROM RABI TO JOSEPHSON DYNAMICS IN TWO-COUPLED BOSE–EINSTEIN CONDENSATES AS A PHASE TRANSITION PROCESS

2002 ◽  
Vol 16 (27) ◽  
pp. 1021-1026 ◽  
Author(s):  
ARANYABHUTI BHATTACHERJEE ◽  
MAN MOHAN
Keyword(s):  
Phase Transition ◽  
Mean Field ◽  
Perturbation Expansion ◽  
Transition Process ◽  
Field Energy ◽  
Linear Perturbation ◽  
Small Oscillations ◽  
Phase Transition Process ◽  
Tunneling Matrix Element ◽  
Bose Einstein

Crossover from individual Rabi dynamics to collective Josephson dynamics in two-coupled Bose–Einstein condensates is studied as a phase transition process. We obtain the critical value of the parameter Λ (ratio of the mean field energy to the tunneling matrix element) for the π-phase oscillations from the non-linear perturbation expansion of small oscillations around the saddle point of the first-order Euclidean (imaginary time) differential equations for polar and azimuthal angles θ and ϕ without approximation.

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