Results 231 to 240 of about 519,262 (262)

On the yield stress of nanocrystals

Journal of Materials Science, 1993
A generalization of the Hall-Petch relationship is proposed. The generalized relationship takes account of the contributions from intergrain sliding, generation of lattice dislocations, and influence of disclination-like defects. From this approach, a critical size corresponding to a maximum of the Hall-Petch size dependence is obtained.
V. G. Gryaznov, M. Yu. Gutkin, A. E. Romanov, L. I. Trusov   +3 more
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Helical Locomotion in Yield Stress Fluids

Physical Review Letters, 2023
We report three stages for locomotion of a helical swimmer in yield stress fluids. In the first stage, the swimmer must overcome the material's yield strain to generate rotational motion. However, exceeding the first threshold is not sufficient for locomotion.
Farshad Nazari, Kourosh Shoele, Hadi Mohammadigoushki   +2 more
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An apparatus to detect a yield stress in blood

Biorheology, 1969
A new parallel plate instrument for the detection of a yield stress of blood is described. Its calibration and performance with materials of known properties are outlined, together with brief details of results obtained with blood. These results are shown to be consistent with those obtained by some other workers using various methods.
D N, Walder, J P, Weaver, A, Evans
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Analysis of shear rheometry of yield stress materials and apparent yield stress materials

Rheologica Acta, 2002
For the most common types of viscometers the apparent flow curve of plastic fluids is studied. For torsional flow, where the shear rate is the natural variable, the apparent yield stress exceeds the true yield stress $$\tau _c $$ by more than 33%.
Peter Brunn, Hesham Asoud
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Blood yield stress in systemic sclerosis

American Journal of Physiology-Heart and Circulatory Physiology, 1999
Blood is a weak percolating physical gel at low shear rates, in which clusters of aggregates can be reversibly disaggregated or formed again. This phenomenon is of potential importance in the microvascular pathophysiology of ischemic and vasospastic disorders such as systemic sclerosis. The aim of this work was to determine blood yield stress using low-
C, Picart, P H, Carpentier, H, Galliard, J M, Piau   +3 more
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Viscous Fingering in a Yield Stress Fluid

Physical Review Letters, 2000
We study the Saffman-Taylor or viscous fingering instability in yield stress fluids. The theory for yield stress fluids shows that the dispersion equation of the instability is similar to that for Newtonian fluids; however, the capillary number governing the instability now contains the yield stress.
, Lindner, , Coussot, , Bonn
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Rapid Spreading of Yield-Stress Liquids

Langmuir
When a liquid drop makes initial contact with any surface, an unbalanced surface tension force drives the contact line, causing spreading. For Newtonian liquids, either liquid inertia or viscosity dictates these early regimes of spreading, albeit with different power-law behaviors of the evolution of the dynamic spreading radius.
Surjyasish Mitra, A-Reum Kim, Boxin Zhao, Sushanta K. Mitra   +3 more
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Yield Stress of Multimodal Powder Suspensions: An Extension of the YODEL (Yield Stress mODEL)

Journal of the American Ceramic Society, 2007
The prediction of the rheological properties of concentrated suspensions is of great importance both in industrial processes (ceramics, cements, and pharmaceutics) and natural phenomena (debris flow, soil erosion). In a previous paper, we presented a new model (YODEL) that can predict the yield stress of concentrated particulate ...
Flatt, Robert J., Bowen, Paul
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Yield limit analysis of particle motion in a yield-stress fluid

Journal of Fluid Mechanics, 2017
A theoretical and numerical study of yield-stress fluid creeping flow about a particle is presented. Yield-stress fluids can hold rigid particles statically buoyant if the yield stress is large enough. In addressing sedimentation of rigid particles in viscoplastic fluids, we should know this critical ‘yield number’ beyond which there is no motion.
Emad Chaparian, Ian A. Frigaard
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Yield Stress Measurements

1990
Much has been written about the yield stress, specially in the field of blood rheology. The definition of the yield stress is very clear and says that this is the smallest load under which a substance will flow. Its measure is the yield stress value of the applied shear stress.
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