scholarly journals Effective viscosity of a random mixture of fluids

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Benoît Noetinger ◽  
Laurène Hume ◽  
Robin Chatelin ◽  
Philippe Poncet
Keyword(s):  
Effective Viscosity ◽  
Random Mixture

Smooth endoplasmic reticulum in perfusion and immersion-fixed Leydig cells

1990 ◽  
Vol 48 (3) ◽  
pp. 82-83
Author(s):  
R.T.F. Bernard ◽  
R.H.M. Cross
Keyword(s):  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
Steroid Hormones ◽  
Transmission Electron Microscope ◽  
Leydig Cells ◽  
Smooth Endoplasmic Reticulum ◽  
Random Mixture ◽  
Transmission Electron

Smooth endoplasmic reticulum (SER) is involved in the biosynthesis of steroid hormones, and changes in the organisation and abundance of this organelle are regularly used as indicators of changes in the level of steroidogenesis. SER is typically arranged as a meshwork of anastomosing tubules which, with the transmission electron microscope, appear as a random mixture of cross, oblique and longitudinal sections. Less commonly the SER appears as swollen vesicles and it is generally suggested that this is an artefact caused during immersion fixation or during immersion of poorly-perfused tissue.During a previous study of the Leydig cells of a seasonally reproducing bat, in which tissue was fixed by immersion, we noted that tubular SER and vesicular SER often occured in adjacent cells and sometimes in the same cell, and that the abundance of the two types of SER changed seasonally. We came to doubt the widelyheld dogma that vesicular SER was an artefact of immersion fixation and set out to test the hypothesis that the method of fixation does not modify the ultrastructure of the SER.

Effects of Sonication Time on the Stability and Viscosity of Functionalized MWCNT-Based Nanolubricants

2020 ◽  
Vol 16 (4) ◽  
pp. 639-654
Author(s):  
Ahmet Selim Dalkilic ◽  
Bedri Onur Küçükyıldırım ◽  
Ayşegül Akdoğan Eker ◽  
Faruk Yıldız ◽  
Altuğ Akpinar ◽  
...  
Keyword(s):  
Effective Viscosity ◽  
Mass Concentration ◽  
Measured Data ◽  
Sonication Time ◽  
Empirical Correlations ◽  
Thermal Systems ◽  
The Stability ◽  
Rotary Viscometer ◽  
Functionalized Mwcnts ◽  
Measured Viscosity

Background: Active scholars in the nanofluid field have continuously attempted to remove the associated challenge of the stability of nanofluids via various approaches, such as functionalization and adding a surfactant. After preparing a stable nanofluid, one must measure the properties, as this is vital in the design of thermal systems. Objective: Authors aimed to investigate the stability and viscosity of refrigeration lubrication oilbased nanofluids containing functionalized MWCNTs. The effects of concentration and temperature on viscosity were studied. Furthermore, the present study focused on the effect of sonication time on the stability and viscosity of the prepared samples. Methods: After the preparation of chemically functionalized MWCNTs, solutions were dispersed with an ultrasonic homogenizer for 2, 4 and 8 hours sonication at maximum power. Viscosity measurements for all samples were made 10 minutes after sonication by adjusting the proper spinning velocity using a digital rotary viscometer. Results: The first part deals with the stability of the nanofluid as a nanolubricant, and the second one investigates the viscosity of the nanofluid and the effects of various parameters on it. The last one is related to the validation of the measured viscosity values by means of well-known empirical correlations. The measured data are given for validation issues. Conclusion: The samples will have higher stability by increasing the time of sonication. The viscosity of a nanofluid does not change with the increase of sonication time to two hours and higher. Up to mass concentration of 0.1%, the effective viscosity increases with adding nanotubes linearly.

A general model for the effective viscosity of pseudoplastic and dilatant fluids

1975 ◽  
Vol 14 (5) ◽  
pp. 404-409 ◽  
Author(s):  
St. W. Churchill ◽  
R. U. Churchill
Keyword(s):  
General Model ◽  
Effective Viscosity

Human Handedness and Scalp Hair-Whorl Direction Develop From a Common Genetic Mechanism

Genetics ◽  
2003 ◽  
Vol 165 (1) ◽  
pp. 269-276
Author(s):  
Amar J S Klar
Keyword(s):  
Scalp Hair ◽  
Single Gene ◽  
Monozygotic Twins ◽  
Hand Preference ◽  
Genetic Mechanism ◽  
Internal Organs ◽  
Genetic Pathways ◽  
Left Hand ◽  
Learned Behavior ◽  
Random Mixture

Abstract Theories concerning the cause of right- or left-hand preference in humans vary from purely learned behavior, to solely genetics, to a combination of the two mechanisms. The cause of handedness and its relation to the biologically specified scalp hair-whorl rotation is determined here. The general public, consisting of mostly right-handers (RH), shows counterclockwise whorl rotation infrequently in 8.4% of individuals. Interestingly, non-right-handers (NRH, i.e., left-handers and ambidextrous) display a random mixture of clockwise and counterclockwise swirling patterns. Confirming this finding, in another independent sample of individuals chosen because of their counterclockwise rotation, one-half of them are NRH. These findings of coupling in RH and uncoupling in NRH unequivocally establish that these traits develop from a common genetic mechanism. Another result concerning handedness of the progeny of discordant monozygotic twins suggests that lefties are one gene apart from righties. Together, these results suggest (1) that a single gene controls handedness, whorl orientation, and twin concordance and discordance and (2) that neuronal and visceral (internal organs) forms of bilateral asymmetry are coded by separate sets of genetic pathways. The sociological impact of the study is discussed.

Growth and Atomistic Structure Study of Disordered SiGe Mixed Semiconductors

2007 ◽  
Vol 539-543 ◽  
pp. 2043-2047 ◽  
Author(s):  
Ichiro Yonenaga ◽  
Masaki Sakurai ◽  
Marcel H.F. Sluiter
Keyword(s):  
Structure Study ◽  
Suitable Model ◽  
Bond Lengths ◽  
Random Mixture ◽  
Mixed Material ◽  
X Ray Absorption ◽  
Ab Inito ◽  
Structure Calculations ◽  
Atomistic Structure ◽  
Good Agreement

The atomistic structure of Czochralski-grown SixGe1-x binary mixed semiconductor was studied experimentally and theoretically. By extended X-ray absorption fine structure (XAFS) studies it was found that bulk SiGe semiconductor is a random mixture and that the Ge-Ge, Ge-Si and Si-Si bond lengths maintain distinctly different lengths and vary in a linear fashion against the alloy composition across the whole composition range 0 < x < 1, in good agreement with expectations derived from the ab-inito electronic structure calculations. The result indicates that SiGe is a suitable model for a disorder mixed material and that the bond lengths and bond angles are distorted with the composition.

Proton NMR in a random mixture with competing anisotropies: CsMn1-xCoxCl3·2H2O

1986 ◽  
Vol 54-57 ◽  
pp. 35-36 ◽  
Author(s):  
H. Kubo ◽  
N. Uryǔ ◽  
T. Hamasaki ◽  
M. Hidaka ◽  
H. Nishihara ◽  
...  
Keyword(s):  
Proton Nmr ◽  
Random Mixture

Dispersion Flow in Microchannels

2012 ◽  
Author(s):  
Alfir T. Akhmetov ◽  
Marat V. Mavletov ◽  
Sergey P. Sametov ◽  
Artur A. Rakhimov ◽  
Azat A. Valiev ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Effective Viscosity ◽  
Complex Structure ◽  
Experimental Investigations ◽  
Dispersed Phase ◽  
Rheological Characteristics ◽  
Dense Structure ◽  
The Third ◽  
Dynamic Blocking ◽  
Oil Emulsions

The work is devoted to experimental investigations of the features of flow of dispersions in microchannels. The paper consists of three parts. In the first part the flow of emulsions in smooth contracting cylindrical microchannels is investigated. It is received that a significant role at dynamic blocking of channels is played by the inclusions comparable by size to the diameter of a narrowing. This is in spite of the fact that their influence on the change of a flow rate of emulsion before blocking is insignificant. In the second part the generation of emulsion in a complex structure of microchannels (micromodels) when water is displaced by composition of hydrocarbon with surfactants is investigated. The experimental dependences of the rheological characteristics of emulsions based on the composition of SAS and water at different concentrations of the aqueous phase can explain blocking of a porous structure by generated emulsion. In the third part a comparison of flow of water-in-oil emulsions with the suspension which was obtained by freezing the microdroplets of the aqueous phase of emulsions was studied. It was found that the blocking of suspension is not as complete as in the case of emulsion. It is explained by deformation of the droplets and by formation of a dense structure, as opposed to suspension of beads, through which hydrocarbon phase is filtered. A small increase in effective viscosity due to solidification of freezing droplets of the dispersed phase was found.

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