scholarly journals Direct observation of dynamic shear jamming in dense suspensions

Nature ◽  
2016 ◽  
Vol 532 (7598) ◽  
pp. 214-217 ◽  
Author(s):  
Ivo R. Peters ◽  
Sayantan Majumdar ◽  
Heinrich M. Jaeger
Keyword(s):  
Direct Observation ◽  
Dynamic Shear ◽  
Dense Suspensions ◽  
Shear Jamming

scholarly journals Controlling shear jamming in dense suspensions via the particle aspect ratio

Soft Matter ◽  
2019 ◽  
Vol 15 (18) ◽  
pp. 3649-3654 ◽  
Author(s):  
Nicole M. James ◽  
Huayue Xue ◽  
Medha Goyal ◽  
Heinrich M. Jaeger
Keyword(s):  
Aspect Ratio ◽  
Shear Thickening ◽  
Dense Suspensions ◽  
Shear Jamming ◽  
Particle Aspect Ratio

Dense suspensions of particles in a liquid exhibit rich, non-Newtonian behaviors such as shear thickening (ST) and shear jamming (SJ).

scholarly journals Shear jamming and fragility in dense suspensions

2019 ◽  
Vol 21 (3) ◽  
Author(s):  
Ryohei Seto ◽  
Abhinendra Singh ◽  
Bulbul Chakraborty ◽  
Morton M. Denn ◽  
Jeffrey F. Morris
Keyword(s):  
Dense Suspensions ◽  
Shear Jamming

scholarly journals Dynamic shear jamming in dense granular suspensions under extension

2017 ◽  
Vol 95 (1) ◽  
Author(s):  
Sayantan Majumdar ◽  
Ivo R. Peters ◽  
Endao Han ◽  
Heinrich M. Jaeger
Keyword(s):  
Dynamic Shear ◽  
Granular Suspensions ◽  
Shear Jamming

scholarly journals Orientational arrest in dense suspensions of elliptical particles under oscillatory shear flows

2021 ◽  
Author(s):  
Zakiyeh Yousefian ◽  
Martin Trulsson
Keyword(s):  
Aspect Ratio ◽  
Shear Flows ◽  
Oscillatory Shear ◽  
Large Strains ◽  
Nematic Order ◽  
Rheological Response ◽  
Lower Viscosity ◽  
Dense Suspensions ◽  
Elliptical Particles ◽  
Shear Jamming

Abstract We study the rheological response of dense suspensions of elliptical particles, with an aspect ratio equal to 3, under oscillatory shear flows and imposed pressure by numerical simulations. Like for the isotropic particles, we find that the oscillatory shear flows respect the Cox-Merz rule at large oscillatory strains but differ at low strains, with a lower viscosity than the steady shear and higher shear jamming packing fractions. However, unlike the isotropic cases (i.e., discs and spheres), frictionless ellipses get dynamically arrested in their initial orientational configuration at small oscillatory strains. We illustrate this by starting at two different configurations with different nematic order parameters and the average orientation of the particles. Surprisingly, the overall orientation in the frictionless case is uncoupled to the rheological response close to jamming, and the rheology is only controlled by the average number of contacts and the oscillatory strain. Having larger oscillatory strains or adding friction does, however, help the system escape these orientational arrested states, which are evolving to a disordered state independent of the initial configuration at low strains and ordered ones at large strains.

scholarly journals Interparticle hydrogen bonding can elicit shear jamming in dense suspensions

2018 ◽  
Vol 17 (11) ◽  
pp. 965-970 ◽  
Author(s):  
Nicole M. James ◽  
Endao Han ◽  
Ricardo Arturo Lopez de la Cruz ◽  
Justin Jureller ◽  
Heinrich M. Jaeger
Keyword(s):  
Hydrogen Bonding ◽  
Dense Suspensions ◽  
Shear Jamming

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

Application of a Simple Cold Stub to the Direct Observation of Frozen Hydrated Sand

1973 ◽  
Vol 31 ◽  
pp. 212-213
Author(s):  
John M. Wehrung ◽  
Richard J. Harniman
Keyword(s):  
United States ◽  
Surface Water ◽  
Direct Observation ◽  
Controlled Study ◽  
Clay Particles ◽  
Organic Debris ◽  
Rock Formations ◽  
Water Tables ◽  
Permeable Rock ◽  
Natural Means

Water tables in aquifer regions of the southwest United States are dropping off at a rate which is greater than can be replaced by natural means. It is estimated that by 1985 wells will run dry in this region unless adequate artificial recharging can be accomplished. Recharging with surface water is limited by the plugging of permeable rock formations underground by clay particles and organic debris.A controlled study was initiated in which sand grains were used as the rock formation and water with known clay concentrations as the recharge media. The plugging mechanism was investigated by direct observation in the SEM of frozen hydrated sand samples from selected depths.

Direct Observation of the Diffusionless β → β + ω Transformation in Titanium Alloys

1971 ◽  
Vol 29 ◽  
pp. 122-123
Author(s):  
N. E. Paton ◽  
D. de Fontaine ◽  
J. C. Williams
Keyword(s):  
Electron Microscope ◽  
Titanium Alloys ◽  
Direct Observation ◽  
Dark Field ◽  
X Ray Diffraction ◽  
Resistivity Measurements ◽  
Selected Area Electron Diffraction ◽  
Ti Alloys ◽  
Thin Foils ◽  
Field Device

The electron microscope has been used to study the diffusionless β → β + ω transformation occurring in certain titanium alloys at low temperatures. Evidence for such a transformation was obtained by Cometto et al by means of x-ray diffraction and resistivity measurements on a Ti-Nb alloy. The present work shows that this type of transformation can occur in several Ti alloys of suitable composition, and some of the details of the transformation are elucidated by means of direct observation in the electron microscope.Thin foils were examined in a Philips EM-300 electron microscope equipped with a uniaxial tilt, liquid nitrogen cooled, cold stage and a high resolution dark field device. Selected area electron diffraction was used to identify the phases present and the ω-phase was imaged in dark field by using a (101)ω reflection. Alloys were water quenched from 950°C, thinned, and mounted between copper grids to minimize temperature gradients in the foil.

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