Domain restructurization in ferroelectrics within the phase transition range

1975 ◽  
Vol 18 (5) ◽  
pp. 704-706 ◽  
Author(s):  
V. S. Rumyantsev ◽  
V. M. Rudyak
Keyword(s):  
Phase Transition ◽  
Transition Range ◽  
Phase Transition Range

Influence of mixed organic cations on the structural and optical properties of lead tri-iodide perovskites

Nanoscale ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 5215-5221 ◽  
Author(s):  
Guotao Pang ◽  
Xiaoqi Lan ◽  
Ruxue Li ◽  
Zhubing He ◽  
Rui Chen
Keyword(s):  
Phase Transition ◽  
Optical Properties ◽  
Organic Cation ◽  
Organic Cations ◽  
Temperature Dependent ◽  
Structural And Optical Properties ◽  
Transition Range ◽  
Phase Transition Range ◽  
Temperature Dependent Photoluminescence

Temperature-dependent photoluminescence in the phase transition range shows that mixed-organic-cation perovskites are more stable than their pure counterparts.

The Influence of Thermomechanical Treatment on R–Phase Transition and Shape Memory Effect

1991 ◽  
Vol 246 ◽  
Author(s):  
Guo Jinfang ◽  
Cheng Yuying ◽  
Zhu Ming ◽  
Shen Long ◽  
Yuan Guansen
Keyword(s):  
Phase Transition ◽  
Memory Effect ◽  
Shape Recovery ◽  
Annealing Temperature ◽  
Cold Deformation ◽  
Tini Alloy ◽  
Phase Transformation Temperature ◽  
Transition Range ◽  
Phase Transition Range ◽  
The Stability

AbstractThis paper discussed the influence of cold working and annealing process on R–phase SME in an equiatomic TiNi alloy by means of tensile test, phase transformation, temperature measurement, and shape recovery examination. The results show that the increase in cold deformation of TiNi alloy got the increase in both tensile strength and R–phasc transition (TR–Ms). As R–phase becomes stable, the SME will be improved and the decay of memory effect will also be controlled at fatique test. The increase in annealing temperature got the decrease in R–phase transition range. In that case the stability of R–phase and the SME of the alloy also become bad. When annealing at 600°C, the recrystallization occurs no R–phase is found. Surely the SME of alloy becomes bad.

Dependence on neutral salt concentration of the latency phase in the time course of hydrolysis of dimyristoylphosphatidylcholine liposomes by phospholipase A2

1991 ◽  
Vol 69 (10-11) ◽  
pp. 715-721 ◽  
Author(s):  
Marta S. Fernández ◽  
Ricardo Mejía ◽  
Eunice Zavala ◽  
Fermín Pacheco
Keyword(s):  
Phase Transition ◽  
Time Course ◽  
Latency Period ◽  
High Salt ◽  
Phospholipase A ◽  
Neutral Salt ◽  
Transition Range ◽  
Nacl Concentration ◽  
Lag Period ◽  
Phase Transition Range

The time course of the hydrolytic action of porcine pancreatic phospholipase A2 on sonicated dimyristoylphosphatidylcholine liposomes in the presence of variable NaCl concentrations has been studied at temperatures between 17 and 36 °C; at these temperatures liposomes are in the gel phase. At a NaCl concentration of 10 mM, the hydrolysis shows a small and constant lag period of 6–8 min at all temperatures within this range. As the temperature is raised into the liquid crystalline range, the latency phase lengthens monotonically so that at 36 °C it reaches 55 min. An increase in the NaCl concentration to 1 M makes the lag period longer at all temperatures studied, with the exception of the phase transition range (near 24 °C); within this temperature range, a small reduction in the lag time is observed. The increase in the length of the latency period at high salt concentrations may be due to screening of the negative surface charge generated by the nascent fatty acid which seems to be essential for the efficient interfacial binding of the enzyme. In the phase transition range of the lamellae, the unfavorable effect of high salt concentrations on the electrostatic binding of the enzyme appears to be overcome by another type of interaction. Recent findings raise the possibility that this interaction could be hydrophobic in nature.Key words: phospholipase A2, liposomes, hydrolysis, salt, latency phase.

Reflection of elastic waves in a crystal of Heusler alloy Ni2MnGa in the phase transition range

2009 ◽  
Vol 54 (1) ◽  
pp. 82-88
Author(s):  
M. M. Karpuk ◽  
D. A. Kostiuk ◽  
Yu. A. Kuzavko ◽  
V. G. Shavrov
Keyword(s):  
Phase Transition ◽  
Elastic Waves ◽  
Heusler Alloy ◽  
Transition Range ◽  
Phase Transition Range

Extensional and shear flows, and general rheology of concentrated emulsions of deformable drops

2015 ◽  
Vol 779 ◽  
pp. 197-244 ◽  
Author(s):  
Alexander Z. Zinchenko ◽  
Robert H. Davis
Keyword(s):  
Phase Transition ◽  
Shear Viscosity ◽  
Simple Shear ◽  
High Surface ◽  
Variable Coefficients ◽  
Constitutive Modelling ◽  
Boundary Integral ◽  
Transition Range ◽  
Partially Ordered ◽  
Wide Range

The rheology of highly concentrated monodisperse emulsions is studied by rigorous multidrop numerical simulations for three types of steady macroscopic flow, (i) simple shear ($\dot{{\it\gamma}}x_{2}$, 0 0), (ii) planar extension (PE) ($\dot{{\it\Gamma}}x_{1},-\dot{{\it\Gamma}}x_{2},0$) and (iii) mixed ($\dot{{\it\gamma}}x_{2}$, $\dot{{\it\gamma}}{\it\chi}x_{1}$, 0), where $\dot{{\it\gamma}}$ and $\dot{{\it\Gamma}}$ are the deformation rates, and ${\it\chi}\in (-1,1)$ is the flow parameter, in order to construct and validate a general constitutive model for emulsion flows with arbitrary kinematics. The algorithm is a development of the multipole-accelerated boundary-integral (BI) code of Zinchenko & Davis (J. Fluid Mech., vol. 455, 2002, pp. 21–62). It additionally incorporates periodic boundary conditions for (ii) and (iii) (based on the reproducible lattice dynamics of Kraynik–Reinelt for PE), control of surface overlapping, much more robust controllable surface triangulations for long-time simulations, and more efficient acceleration. The emulsion steady-state viscometric functions (shear viscosity and normal stress differences) for (i) and extensiometric functions (extensional viscosity and stress cross-difference) for (ii) are studied in the range of drop volume fractions $c=0.45{-}0.55$, drop-to-medium viscosity ratios ${\it\lambda}=0.25{-}10$ and various capillary numbers $\mathit{Ca}$, with 100–400 drops in a periodic cell and 2000–4000 boundary elements per drop. High surface resolution is important for all three flows at small $\mathit{Ca}$. Large system size and strains $\dot{{\it\gamma}}t$ of up to several thousand are imperative in some shear-flow simulations to identify the onset of phase transition to a partially ordered state, and evaluate (although still not precisely) the viscometric functions in this state. Below the phase transition point, the shear viscosity versus $\mathit{Ca}$ shows a kinked behaviour, with the local minimum most pronounced at ${\it\lambda}=1$ and $c=0.55$. The ${\it\lambda}=0.25$ emulsions flow in a partially ordered manner in a wide range of $\mathit{Ca}$ even when $c=0.45$. Increase of ${\it\lambda}$ to 3–10 shifts the onset of ordering to much smaller $\mathit{Ca}$, often outside the simulation range. In contrast to simple shear, phase transition is never observed in PE or mixed flow. A generalized five-parameter Oldroyd model with variable coefficients is fitted to our extensiometric and viscometric functions at arbitrary flow intensities (but outside the phase transition range). The model predictions compare very well with precise simulation results for strong mixed flows, ${\it\chi}=0.25$. Time-dependent PE flow is also considered. Ways to overcome the phase transition and drop breakup limitations on constitutive modelling are discussed.

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