Rheophysics of highly concentrated coarse-particle suspensions in a wide-gap Couette rheometer

2009 ◽  
Author(s):  
S. Wiederseiner ◽  
C. Ancey ◽  
M. Rentschler ◽  
N. Andreini ◽  
Masami Nakagawa ◽  
...  
Keyword(s):  
Coarse Particle ◽  
Particle Suspensions ◽  
Wide Gap ◽  
Couette Rheometer

Simple and Accurate Formulas for Flow-Curve Recovery from Couette Rheometer Data

2006 ◽  
Vol 16 (6) ◽  
pp. 321-328 ◽  
Author(s):  
F. R. De Hoog ◽  
R. S. Anderssen
Keyword(s):  
Flow Curve ◽  
Current Flow ◽  
Numerical Differentiation ◽  
Narrow Gap ◽  
Velocity Data ◽  
Flow Curves ◽  
Sum Formula ◽  
Wide Gap ◽  
Couette Rheometer ◽  
Improved Accuracy

Abstract In Couette rheometry, most of the current flow-curve recovery algorithms require the explicit numerical differentiation of the measured angular velocity data. The exceptions and popular choices, because it avoids the need for a numerical differentiation, are the parallel plate approximation (cf. Bird et al. [1], Table 10.2-1) and the simplest of the formulas given in Krieger and Elrod [2]. However, their applicability is limited to narrow gap rheometer data. In this paper, equally simple formulas are presented which are exact for Newtonian fluids, do not involve a numerical differentiation and are consistently more accurate than the simple formulas mentioned above. They are based on a generalization of the Euler-Maclaurin sum formula solution of the Couette viscometry equation given in Krieger and Elrod. As well as illustrating the improved accuracy for the recovery of flow-curves for fluids with and without a yield-stress, details about more general and accurate formulas for flow-curve recovery from Couette rheometry data are given. The situation for the recovery of flow-curves from wide gap rheometery measurements is also discussed.

Platelet Adhesion to Native Collagens Involves Proteoglycans and May Be a Two-Step Process

1987 ◽  
Vol 58 (02) ◽  
pp. 786-789 ◽  
Author(s):  
O Behnke
Keyword(s):  
Electron Microscope ◽  
Platelet Adhesion ◽  
Close Contact ◽  
Blood Platelets ◽  
Collagen Fibrils ◽  
Platelet Membrane ◽  
Step Process ◽  
Rat Blood ◽  
Wide Gap ◽  
Rat Tail

SummaryAdhesion of rat blood platelets to native rat tail collagen fibrils was studied in the electron microscope under conditions that preserved collagen-associated proteoglycans (CAPG). The CAPG molecules were aligned in chain-like configurations that encircled the fibrils with a 65 nm period; they appeared to coat the fibrils completely and extended 60-100 nm away from the fibril. The initial platelet-fibril contact occurred between the platelet glycocalyx and the CAPG of the fibrils i.e. between two surfaces with net-negative charges. When close contact was established between the fibril surface proper and the platelet membrane, CAPG were not identified in the area of contact, and the collagen-platelet distance was reduced to a ~10-12 nm wide gap traversed by delicate links in register with fibril periodicities.

Carrier-Transport Processes in n+-GaAs/n0-GaAs/n+-GaAs Isotype Heterostructures with a Thin Wide-Gap AlGaAs Barrier

2020 ◽  
Vol 54 (5) ◽  
pp. 529-533
Author(s):  
S. O. Slipchenko ◽  
A. A. Podoskin ◽  
O. S. Soboleva ◽  
V. S. Yuferev ◽  
V. S. Golovin ◽  
...  
Keyword(s):  
Carrier Transport ◽  
Transport Processes ◽  
Wide Gap

The Problem

2017 ◽  
Author(s):  
Mats Alvesson ◽  
Yiannis Gabriel ◽  
Roland Paulsen
Keyword(s):  
Social Sciences ◽  
Academic Research ◽  
Social Scientists ◽  
Research Papers ◽  
Prestigious Journal ◽  
The Past ◽  
The Social ◽  
Academic Researchers ◽  
History Of ◽  
Wide Gap

This chapter introduces ‘the problem’ of meaningless research in the social sciences. Over the past twenty years there has been an enormous growth in research publications, but never before in the history of humanity have so many social scientists written so much to so little effect. Academic research in the social sciences is often inward looking, addressed to small tribes of fellow researchers, and its purpose in what is increasingly a game is that of getting published in a prestigious journal. A wide gap has emerged between the esoteric concerns of social science researchers and the pressing issues facing today’s societies. The chapter critiques the inaccessibility of the language used by academic researchers, and the formulaic qualities of most research papers, fostered by the demands of the publishing game. It calls for a radical move from research for the sake of publishing to research that has something meaningful to say.

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