scholarly journals Monodisperse drops templated by 3D-structured microparticles

2020 ◽  
Author(s):  
Chueh-Yu Wu ◽  
Bao Wang ◽  
Joseph de Rutte ◽  
Mengxing Ouyang ◽  
Alexis Joo ◽  
...  
Keyword(s):  
Interfacial Energy ◽  
Single Cells ◽  
Cutting Edge ◽  
Immiscible Fluid ◽  
New Approaches ◽  
Formation Conditions ◽  
Surface Chemistries ◽  
Fluid Phases

AbstractThe ability to create uniform sub-nanoliter compartments using microfluidic control has enabled new approaches for analysis of single cells and molecules. However, specialized instruments or expertise have been required, slowing the adoption of these cutting-edge applications. Here, we show that 3D-structured microparticles with sculpted surface chemistries template uniformly-sized aqueous drops when simply mixed with two immiscible fluid phases. In contrast to traditional emulsions, particle-templated drops of a controlled volume occupy a minimum in the interfacial energy of the system, such that a stable monodisperse state results with simple and reproducible formation conditions. We describe techniques to manufacture microscale drop-carrier particles and show that emulsions created with these particles prevent molecular exchange, concentrating reactions within the drops, laying a foundation for sensitive compartmentalized assays with minimal instrumentation.

scholarly journals Monodisperse drops templated by 3D-structured microparticles

2020 ◽  
Vol 6 (45) ◽  
pp. eabb9023
Author(s):  
Chueh-Yu Wu ◽  
Mengxing Ouyang ◽  
Bao Wang ◽  
Joseph de Rutte ◽  
Alexis Joo ◽  
...  
Keyword(s):  
Interfacial Energy ◽  
Single Cells ◽  
Three Dimensional ◽  
Cutting Edge ◽  
Immiscible Fluid ◽  
New Approaches ◽  
Formation Conditions ◽  
Surface Chemistries ◽  
Fluid Phases

The ability to create uniform subnanoliter compartments using microfluidic control has enabled new approaches for analysis of single cells and molecules. However, specialized instruments or expertise has been required, slowing the adoption of these cutting-edge applications. Here, we show that three dimensional–structured microparticles with sculpted surface chemistries template uniformly sized aqueous drops when simply mixed with two immiscible fluid phases. In contrast to traditional emulsions, particle-templated drops of a controlled volume occupy a minimum in the interfacial energy of the system, such that a stable monodisperse state results with simple and reproducible formation conditions. We describe techniques to manufacture microscale drop-carrier particles and show that emulsions created with these particles prevent molecular exchange, concentrating reactions within the drops, laying a foundation for sensitive compartmentalized molecular and cell-based assays with minimal instrumentation.

An evaluation of synthetic fluid inclusions for the purpose of trapping equilibrated, coexisting, immiscible fluid phases at magmatic conditions

2007 ◽  
Vol 92 (1) ◽  
pp. 124-138 ◽  
Author(s):  
A. C. Simon ◽  
M. R. Frank ◽  
T. Pettke ◽  
P. A. Candela ◽  
P. M. Piccoli ◽  
...  
Keyword(s):  
Fluid Inclusions ◽  
Immiscible Fluid ◽  
Synthetic Fluid Inclusions ◽  
Fluid Phases

The Future of Security Studies

2018 ◽  
pp. 2-13
Author(s):  
Alexandra Gheciu ◽  
William C. Wohlforth
Keyword(s):  
International Security ◽  
The State ◽  
Cutting Edge ◽  
Security Studies ◽  
Great Power ◽  
New Approaches ◽  
The Future ◽  
State Of The Field

We situate the chapters that follow in the changing context of the study and practice of international security and show how rigorous thinking about the future informs the volume. Dramatic changes in the international security landscape against the backdrop of the increased salience of the classical security agenda of great power rivalry call for a new state-of-the-field compendium. The state of the field, meanwhile, is not what it was even a few years ago, with the rise of new approaches and the transformation of older ones. By asking leading thinkers to address developments in international security through a future-oriented lens, we are able to present readers with a comprehensive and cutting edge guide to the field.

scholarly journals Dynamic permeability functions for partially saturated porous media

2020 ◽  
Vol 221 (2) ◽  
pp. 1182-1189
Author(s):  
Santiago G Solazzi ◽  
J Germán Rubino ◽  
Damien Jougnot ◽  
Klaus Holliger
Keyword(s):  
Porous Media ◽  
Effective Permeability ◽  
Pore Space ◽  
Pore Fluid ◽  
Immiscible Fluid ◽  
Saturated Porous Media ◽  
Partially Saturated ◽  
Dynamic Permeability ◽  
Partially Saturated Porous Media ◽  
Fluid Phases

SUMMARY While the frequency-dependence of permeability under fully saturated conditions has been studied for decades, the corresponding characteristics of partially saturated porous media remain unexplored. Notably, it is not clear whether the use of effective pore fluid approaches under such conditions is valid. To address this issue, we propose a method that allows us to obtain dynamic permeability functions for partially saturated porous media. To this end, we conceptualize the considered pore space as a bundle of capillary tubes of different radii saturated by two immiscible fluid phases. We then solve the Navier–Stokes equations within the pore space and define a capillary pressure–saturation relationship, which permits to obtain saturation- and frequency-dependent effective permeability estimates. The application of this method to a realistic model of an unconsolidated granular sediment demonstrates that dynamic effective permeability functions for wetting and non-wetting fluid phases exhibit distinct characteristics, thus rendering effective pore fluid approaches inadequate. Finally, we explore the capability of the seminal dynamic permeability model developed by Johnson et al.[J. Fluid Mech. 176, 379 (1987)] to account for the effects of partial saturation. We find that the frequency scaling proposed by Johnson et al. prevails in partially saturated scenarios. However, the parameters associated with this model need to be redefined to account for saturation-dependent effects.

scholarly journals On the Intersection of Leadership and Populism in North America and Europe

2020 ◽  
Vol 8 (1) ◽  
pp. 107-110
Author(s):  
Cristine De Clercy
Keyword(s):  
North America ◽  
Political Leadership ◽  
Cutting Edge ◽  
Thematic Issue ◽  
Approaches To Studying ◽  
Geographic Concentration ◽  
New Approaches ◽  
Methodological Approaches

This editorial introduces the thematic issue and considers what the articles tell us about new approaches to studying political leadership and populism. The editorial surveys the set of eleven articles by referring to their geographic concentration (North America and Europe), along with methodological and thematic similarities. In conclusion, the set of articles displays the diverse theoretical and methodological approaches currently employed in cutting-edge research on populism and political leadership.

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