Search results for "Flow properties"
showing 6 items of 6 documents
Flow properties and hydrodynamic interactions of rigid spherical microswimmers.
2017
We analyze a minimal model for a rigid spherical microswimmer and explore the consequences of its extended surface on the interplay between its self-propulsion and flow properties. The model is the first order representation of microswimmers, such as bacteria and algae, with rigid bodies and flexible propelling appendages. The flow field of such a microswimmer at finite distances significantly differs from that of a point-force (Stokeslet) dipole. For a suspension of microswimmers, we derive the grand mobility matrix that connects the motion of an individual swimmer to the active and passive forces and torques acting on all the swimmers. Our investigation of the mobility tensors reveals tha…
Microrheology of erythrocytes and platelets: physiological basis and consequences for the design and the operation of extracorporeal circulatory devi…
1976
Publisher Summary This chapter discusses the physiological basis and consequences for the design and the operation of extracorporeal circulatory devices. The microrheological response of erythrocytes and thrombocytes can be observed microscopically under simplified flow conditions in the rheoscope. In this device, cells are observed at high magnifications while being subjected to quantifiable shear stresses. Despite the unphysiological environment, the use of this method allowed an important extrapolation to well-established in vivo flow properties and a clear distinction between the primarily passive microrheological properties of the erythrocytes and the microrheological features of throm…
Characterization of the bulk flow properties of industrial powders from shear tests
2020
Bulk flow properties from shear analysis of compacted powders can be evaluated following different approaches. Experimental values of shear stresses obtained by conventional shear cells are traditionally used to build yield loci, from which the most relevant flow properties could be found. Such flow properties play an important role in determining their performance under fluidization conditions. In this work, a useful app, named cYield, was developed by using the new Matlab&rsquo
Impact of sedimentology and diagenesis on the petrophysical properties of a tight oolitic carbonate reservoir. The case of the Oolithe Blanche Format…
2013
18 pages; International audience; The Oolithe Blanche Formation was studied in three quarries, located at the south-eastern edge of the Paris Basin (France). Heterogeneities in reservoir properties were assessed through a sedimentological, diagenetic and petrophysical study. The relationships between depositional settings, diagenesis and petrophysical properties were analysed using detailed petrographic studies, image analysis, Nano CTscans and petrophysical measurements. The carbonate reservoir pore network is mainly controlled by intraparticle microporosity which ensures the connectivity with interparticle meso- and macroporosity. Early cementation vs. early compaction processes (mainly g…
Melt stabilization of wet polyamide 6
2002
Abstract Melt processing of polycondensate polymers must be carried out after careful drying in order to avoid any hydrolytic chain scission caused by the presence of water or other small molecules. In this work, the effect of two different antioxidants on the processing and flow properties of a polyamide 6 sample not dried before processing operations has been studied. One of these stabilizers seems to protect the wet polymer from hydrolytic chain scission. This action has been interpreted considering that the stabilizer hydrolyses instead of the polyamide macromolecules.
Polymorphonuclear leucocyte rheology and cytosolic Ca2+ content after activation in chronic renal failure
2001
SUMMARY: We evaluated polymorphonuclear leucocyte (PMN) flow properties in patients with clinically stable chronic renal failure (CRF) and in control subjects at baseline and after activation with 4-phorbol 12-myristate 13-acetate (PMA) and N-formyl-methionyl-leucyl-phenylalanine (fMLP). Initial relative flow rate (IRFR) and clogging particles (CPs) were obtained using the St. George's Filtrometer, and PMN membrane fluidity was assessed by marking PMNs with 1-(4-(trimethylamino)phenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH). PMN cytosolic Ca2+ concentration was determined by marking PMNs with Fura 2-AM. At baseline, CRF patients showed a significant increase only in PMN cytosolic Ca2+ content.…