Electrocoalescence of drops synchronized by size-dependent flow in microfluidic channels

2006 ◽  
Vol 88 (26) ◽  
pp. 264105 ◽  
Author(s):  
Keunho Ahn ◽  
Jeremy Agresti ◽  
Henry Chong ◽  
Manuel Marquez ◽  
D. A. Weitz
Keyword(s):  
Microfluidic Channels ◽  
Size Dependent ◽  
Dependent Flow

Ion-size dependent electroosmosis of viscoelastic fluids in microfluidic channels with interfacial slip

2017 ◽  
Vol 29 (7) ◽  
pp. 072002 ◽  
Author(s):  
Siddhartha Mukherjee ◽  
Prakash Goswami ◽  
Jayabrata Dhar ◽  
Sunando Dasgupta ◽  
Suman Chakraborty
Keyword(s):  
Viscoelastic Fluids ◽  
Microfluidic Channels ◽  
Interfacial Slip ◽  
Size Dependent ◽  
Ion Size

Size-dependence of the flow threshold in dense granular materials

Soft Matter ◽  
2018 ◽  
Vol 14 (25) ◽  
pp. 5294-5305 ◽  
Author(s):  
Daren Liu ◽  
David L. Henann
Keyword(s):  
Granular Materials ◽  
Granular Flow ◽  
Continuum Model ◽  
Size Dependence ◽  
Nonlocal Continuum ◽  
Size Dependent ◽  
Dense Granular Flow ◽  
Flow Configurations ◽  
Dependent Flow ◽  
Flow Threshold

A size-dependent flow threshold is measured in discrete-element method simulations of dense granular flow across several different flow configurations and may be quantitatively captured using a nonlocal continuum model for dense granular flow.

Size-Dependent Nanoparticle Margination and Adhesion Propensity in a Microchannel

2013 ◽  
Vol 4 (3) ◽  
Author(s):  
Patrick Jurney ◽  
Rachit Agarwal ◽  
Vikramjit Singh ◽  
Krishnendu Roy ◽  
S. V. Sreenivasan ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Rational Design ◽  
Flow Behavior ◽  
Cancer Therapeutics ◽  
Bottom Wall ◽  
Microfluidic Channels ◽  
Elliptical Cross ◽  
Drug Delivery Vehicles ◽  
Shear Rates ◽  
Size Dependent

Intravenous injection of nanoparticles as drug delivery vehicles is a common practice in clinical trials of therapeutic agents to target specific cancerous or pathogenic sites. The vascular flow dynamics of nanocarriers (NCs) in human microcapillaries play an important role in the ultimate efficacy of this drug delivery method. This article reports an experimental study of the effect of nanoparticle size on their margination and adhesion propensity in microfluidic channels of a half-elliptical cross section. Spherical polystyrene particles ranging in diameter from 60 to 970 nm were flown in the microchannels and individual particles adhered to either the top or bottom wall of the channel were imaged using fluorescence microscopy. When the number concentration of particles in the flow was kept constant, the percentage of nanoparticles adhered to the top wall increased with decreasing diameter (d), with the number of particles adhered to the top wall following a d−3 trend. When the volume concentration of particles in solution was kept constant, no discernible trend was found. This experimental finding is explained by the competition between the Brownian force promoting margination and repulsive particle–particle electrostatic forces retarding adhesion to the wall. The 970 nm particles were found to adhere to the bottom wall much more than to the top wall for each of the three physiologically relevant shear rates tested, revealing the effect of gravitational force on the large particles. These findings on the flow behavior of spherical nanoparticles in artificial microcapillaries provide further insight for the rational design of NCs for targeted cancer therapeutics.

Production and STEM examination of controlled-size silver clusters

1983 ◽  
Vol 41 ◽  
pp. 338-339
Author(s):  
M. A. Listvan ◽  
R. P. Andres
Keyword(s):  
Cluster Size ◽  
Metal Clusters ◽  
Experimental Parameter ◽  
Carbon Films ◽  
Metal Species ◽  
Silver Clusters ◽  
Free Jet ◽  
Size Dependent ◽  
Cluster Properties ◽  
Controllable Size

Knowledge of the function and structure of small metal clusters is one goal of research in catalysis. One important experimental parameter is cluster size. Ideally, one would like to produce metal clusters of regulated size in order to characterize size-dependent cluster properties.A source has been developed which is capable of producing microscopic metal clusters of controllable size (in the range 5-500 atoms) This source, the Multiple Expansion Cluster Source, with a Free Jet Deceleration Filter (MECS/FJDF) operates as follows. The bulk metal is heated in an oven to give controlled concentrations of monomer and dimer which were expanded sonically. These metal species were quenched and condensed in He and filtered to produce areosol particles of a controlled size as verified by mass spectrometer measurements. The clusters were caught on pre-mounted, clean carbon films. The grids were then transferred in air for microscopic examination. MECS/FJDF was used to produce two different sizes of silver clusters for this study: nominally Ag6 and Ag50.

Transfer Technique for Electron Microscopy of Membrance Filter Samples

1974 ◽  
Vol 32 ◽  
pp. 554-555
Author(s):  
Lawrence W. Ortiz ◽  
Bonnie L. Isom
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Pore Size ◽  
Membrane Filters ◽  
Size Dependent

A procedure is described for the quantitative transfer of fibers and particulates collected on membrane filters to electron microscope (EM) grids. Various Millipore MF filters (Millipore AA, HA, GS, and VM; 0.8, 0.45, 0.22 and 0.05 μm mean pore size) have been used with success. Observed particle losses have not been size dependent and have not exceeded 10%. With fibers (glass or asbestos) as the collected media this observed loss is approximately 3%.

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