High pressurein situx-ray absorption spectroscopy cell for studying simultaneously the liquid phase and the solid/liquid interface

2005 ◽  
Vol 76 (5) ◽  
pp. 054104 ◽  
Author(s):  
Jan-Dierk Grunwaldt ◽  
Michael Ramin ◽  
Markus Rohr ◽  
Alexej Michailovski ◽  
Greta R. Patzke ◽  
...  
2001 ◽  
Vol 49 (7) ◽  
pp. 1123-1128 ◽  
Author(s):  
D. Chatain ◽  
E. Rabkin ◽  
J. Derenne ◽  
J. Bernardini

2001 ◽  
Author(s):  
D. A. Sinton ◽  
B. R. Baliga

Abstract A computational study of natural convection influenced ice-water systems contained in the annular space between two concentric isothermal spheres is presented. An adaptive-grid control-volume finite element method (CVFEM) formulated for the solution of two-dimensional planar and axisymmetric problems was used in the computer simulations. The grid was designed to delineate the solid-liquid interface using a structured adaptation technique. In this study, attention is limited to three different two-dimensional axisymmetric, steady state, pure ice-water systems, with buoyancy-driven natural convection in the liquid phase: two of these systems involve ice adjacent to the inner sphere, and one system involves ice adjacent to the outer sphere. The dimensionless parameters are the following: a modified Rayleigh number, a density inversion parameter, the Prandtl number, radius ratio, and a temperature ratio. The results presented include solid-liquid interface shapes, streamlines and temperature contours in the liquid phase, and dimensionless local heat flux distributions along the surfaces of the inner and outer spheres, and the interface.


1995 ◽  
Vol 10 (7) ◽  
pp. 1605-1610 ◽  
Author(s):  
Chan-Joong Kim ◽  
Ki-Baik Kim ◽  
Gye-Won Hong ◽  
Ho-Yong Lee

Segregation of second-phase particles within Y1Ba2Cu3O7−y domain was investigated in melt-textured Y-Ba-Cu-O with metal oxide (CeO2, SnO2, and ZrO2) addition. It is found that coarse particles (Y2Ba1Cu1O5) are trapped with a special pattern in the interior of Y1Ba2Cu3O7−y domain, while fine BaCeO3 and BaSnO3 particles are present within the remnant liquid-phase region. During the growth of Y1Ba2Cu3O7−y domain, fine particles appear to be pushed out of the advancing Y1Ba2Cu3O7−y /liquid interface toward the liquid phase. The particle segregation that occurred during peritectic growth of the Y1Ba2Cu3O7−y domain was explained in terms of the Uhlmann-Chalmers-Jackson theory based on the particle interaction at solid/liquid interface.


2019 ◽  
Author(s):  
Mei Wang ◽  
Thilini Umesha Dissanayake ◽  
Chiwoo Park ◽  
Karen J. Gaskell ◽  
Taylor Woehl

<p>Nucleation underlies the formation of many liquid-phase synthetic and natural materials with applications in materials chemistry, geochemistry, biophysics, and structural biology. Most liquid-phase nucleation processes are heterogeneous, occurring at specific nucleation sites at a solid-liquid interface; however, the chemical and topographical identity of these nucleation sites and how nucleation kinetics vary from site-to-site remains mysterious. Here we utilize <i>in situ</i> liquid cell electron microscopy to unveil counterintuitive nanoscale non-uniformities in heterogeneous nucleation kinetics on a macroscopically uniform solid-liquid interface. Time-resolved <i>in situ</i> electron microscopy imaging of silver nanoparticle nucleation at a water-silicon nitride interface showed apparently randomly-located nucleation events at the interface. However, nanometric maps of local nucleation kinetics uncovered nanoscale interfacial domains with either slow or rapid nucleation. Interestingly, the interfacial domains vanished at high supersaturation ratio, giving way to rapid spatially uniform nucleation kinetics. Atomic force microscopy and nanoparticle labeling experiments revealed a topographically flat, chemically heterogeneous interface with nanoscale interfacial domains of functional groups similar in size to those observed in the nanometric nucleation maps. These results, along with a semi-quantitative nucleation model, indicate that a chemically non-uniform interface presenting different free energy barriers to heterogeneous nucleation underlies our observations of non-uniform nucleation kinetics. Overall, our results introduce a new imaging modality, nanometric nucleation mapping, and provide important new insights into the impact of surface chemistry on microscopic spatial variations in heterogeneous nucleation kinetics that have not been previously observed.</p>


2011 ◽  
Vol 299-300 ◽  
pp. 345-349
Author(s):  
Guo Wei Chang ◽  
Shu Ying Chen ◽  
Qing Chun Li ◽  
Li Li Guo ◽  
Xu Dong Yue

The influence of pulse electric field on the columnar crystals growth has been studied by employing pulse electric field vertically to the solid/liquid interface during unidirectional solidification. The results showed that the pulse electric field was favorable to columnar crystals growth with the increase of pulse electric field intensity when the liquid phase was the positive electrode of pulse electric field. The formation of equiaxed crystal was accelerated when the degree of composition supercooling in front edge of solid/liquid interface reached the degree of nucleation supercooling by pulse electric field. When the liquid phase was the negative electrode of pulse electric field, the growth of columnar crystals was hindered, and the formation of equiaxed crystal was accelerated by pulse electric field.


2019 ◽  
Author(s):  
Mei Wang ◽  
Thilini Umesha Dissanayake ◽  
Chiwoo Park ◽  
Karen J. Gaskell ◽  
Taylor Woehl

<p>Nucleation underlies the formation of many liquid-phase synthetic and natural materials with applications in materials chemistry, geochemistry, biophysics, and structural biology. Most liquid-phase nucleation processes are heterogeneous, occurring at specific nucleation sites at a solid-liquid interface; however, the chemical and topographical identity of these nucleation sites and how nucleation kinetics vary from site-to-site remains mysterious. Here we utilize <i>in situ</i> liquid cell electron microscopy to unveil counterintuitive nanoscale non-uniformities in heterogeneous nucleation kinetics on a macroscopically uniform solid-liquid interface. Time-resolved <i>in situ</i> electron microscopy imaging of silver nanoparticle nucleation at a water-silicon nitride interface showed apparently randomly-located nucleation events at the interface. However, nanometric maps of local nucleation kinetics uncovered nanoscale interfacial domains with either slow or rapid nucleation. Interestingly, the interfacial domains vanished at high supersaturation ratio, giving way to rapid spatially uniform nucleation kinetics. Atomic force microscopy and nanoparticle labeling experiments revealed a topographically flat, chemically heterogeneous interface with nanoscale interfacial domains of functional groups similar in size to those observed in the nanometric nucleation maps. These results, along with a semi-quantitative nucleation model, indicate that a chemically non-uniform interface presenting different free energy barriers to heterogeneous nucleation underlies our observations of non-uniform nucleation kinetics. Overall, our results introduce a new imaging modality, nanometric nucleation mapping, and provide important new insights into the impact of surface chemistry on microscopic spatial variations in heterogeneous nucleation kinetics that have not been previously observed.</p>


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