Journal articles: 'Rheology data'

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Xu, Zhe, and Yoshiaki Takahashi. "Molecular Weight Estimation of Cellulose in Ionic Liquid Solution by Fitting Dynamic Viscoelastic Data to Rouse Model." Nihon Reoroji Gakkaishi 45, no. 2 (2017): 119–24. http://dx.doi.org/10.1678/rheology.45.119.

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Burda, Zdzislaw, Malgorzata J. Krawczyk, Krzysztof Malarz, and Malgorzata Snarska. "Wealth Rheology." Entropy 23, no. 7 (June 30, 2021): 842. http://dx.doi.org/10.3390/e23070842.

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We study wealth rank correlations in a simple model of macroeconomy. To quantify rank correlations between wealth rankings at different times, we use Kendall’s τ and Spearman’s ρ, Goodman–Kruskal’s γ, and the lists’ overlap ratio. We show that the dynamics of wealth flow and the speed of reshuffling in the ranking list depend on parameters of the model controlling the wealth exchange rate and the wealth growth volatility. As an example of the rheology of wealth in real data, we analyze the lists of the richest people in Poland, Germany, the USA and the world.

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Vieli, Andreas, Antony J. Payne, Zhijun Du, and Andrew Shepherd. "Numerical modelling and data assimilation of the Larsen B ice shelf, Antarctic Peninsula." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 364, no. 1844 (May 31, 2006): 1815–39. http://dx.doi.org/10.1098/rsta.2006.1800.

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In this study, the flow and rheology of pre-collapse Larsen B ice shelf are investigated by using a combination of flow modelling and data assimilation. Observed shelf velocities from satellite interferometry are used to constrain an ice shelf model by using a data assimilation technique based on the control method. In particular, the ice rheology field and the velocities at the inland shelf boundary are simultaneously optimized to get a modelled flow and stress field that is consistent with the observed flow. The application to the Larsen B ice shelf shows that a strong weakening of the ice in the shear zones, mostly along the margins, is necessary to fit the observed shelf flow. This pattern of bands with weak ice is a very robust feature of the inversion, whereas the ice rheology within the main shelf body is found to be not well constrained. This suggests that these weak zones play a major role in the control of the flow of the Larsen B ice shelf and may be the key to understanding the observed pre-collapse thinning and acceleration of Larsen B. Regarding the sensitivity of the stress field to rheology, the consistency of the model with the observed flow seems crucial for any further analysis such as the application of fracture mechanics or perturbation model experiments.

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Kaplan, Jonathan, Alessandra Bonfanti, and Alexandre Kabla. "RHEOS.jl -- A Julia Package for Rheology Data Analysis." Journal of Open Source Software 4, no. 41 (September 24, 2019): 1700. http://dx.doi.org/10.21105/joss.01700.

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Seryo, Naoki, John J. Molina, and Takashi Taniguchi. "Select Applications of Bayesian Data Analysis and Machine Learning to Flow Problems." Nihon Reoroji Gakkaishi 49, no. 2 (April 15, 2021): 97–113. http://dx.doi.org/10.1678/rheology.49.97.

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Puisto, Antti, Xavier Illa, Mikael Mohtaschemi, and Mikko Alava. "Modeling the rheology of nanocellulose suspensions." Nordic Pulp & Paper Research Journal 27, no. 2 (May 1, 2012): 277–81. http://dx.doi.org/10.3183/npprj-2012-27-02-p277-281.

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Abstract The transient response of a Population Balance based colloidal rheology model is studied in the context of nanofiber suspension rheology research. The model is calibrated against experimental rheology data for cellulose nano-whisker suspension and then subjected to transient shears. The non-equilibrium aggregate size distributions are reported.

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Dees, Marc, Marc Mangnus, Nicolaas Hermans, Wouter Thaens, Anne-Sophie Hanot, and Peter Van Puyvelde. "On the pressure correction of capillary melt rheology data." Rheologica Acta 50, no. 2 (January 22, 2011): 117–24. http://dx.doi.org/10.1007/s00397-011-0529-2.

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Schwarz, W. H. "The Rheology of Saliva." Journal of Dental Research 66, no. 1_suppl (February 1987): 660–66. http://dx.doi.org/10.1177/00220345870660s109.

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The rheology of saliva affects the coating and lubrication of oral surfaces and the consistency of ingested foods. Salivary gland dysfunction can cause tissue damage and dysphagia. Therefore, we have considered the problem of designing a synthetic saliva for medical management. Also, we have measured certain rheological properties [shear-dependent viscosity η (k)] and the frequency-dependent moduli [G′(f) and η′(f)] of normal stimulated whole saliva. Analysis of the rheological data and consideration of requirements for using artificial saliva have resulted in a better understanding of the rheological functions of natural saliva and the desirable characteristics of synthetic saliva. In addition, we have measured rheological properties of two commercial saliva substitutes for comparison.

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Schwarz, W. H. "The Rheology of Saliva." Journal of Dental Research 66, no. 2_suppl (February 1987): 660–66. http://dx.doi.org/10.1177/00220345870660s209.

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The rheology of saliva affects the coating and lubrication of oral surfaces and the consistency of ingested foods. Salivary gland dysfunction can cause tissue damage and dysphagia. Therefore, we have considered the problem of designing a synthetic saliva for medical management. Also, we have measured certain rheological properties [shear-dependent viscosity η(κ)] and the frequency-dependent moduli [G'(f) and η'(f)] of normal stimulated whole saliva. Analysis of the rheological data and consideration of requirements for using artificial saliva have resulted in a better understanding of the rheological functions of natural saliva and the desirable characteristics of synthetic saliva. In addition, we have measured rheological properties of two commercial saliva substitutes for comparison.

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Fullard, Luke, Eric Breard, Clive Davies, Pierre-Yves Lagrée, Stéphane Popinet, and Gert Lube. "Testing the μ(I) granular rheology against experimental silo data." EPJ Web of Conferences 140 (2017): 11002. http://dx.doi.org/10.1051/epjconf/201714011002.

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LANCELLA, F., J. DOFFIN, R. PERRAULT, J. STOLTZ, and X. WANG. "F164. Theoretical model of blood rheology compared with clinical data." Biorheology 32, no. 2-3 (March 1995): 314. http://dx.doi.org/10.1016/0006-355x(95)92276-g.

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Carafa, Michele M. C., and Salvatore Barba. "Determining rheology from deformation data: The case of central Italy." Tectonics 30, no. 2 (March 5, 2011): n/a. http://dx.doi.org/10.1029/2010tc002680.

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Lucas, Lemarié, Anandan Aravind, Petiot Emma, Marquette Christophe, and Courtial Edwin-Joffrey. "Rheology, simulation and data analysis toward bioprinting cell viability awareness." Bioprinting 21 (March 2021): e00119. http://dx.doi.org/10.1016/j.bprint.2020.e00119.

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Liu, Xiao Bo, and Wen Kang Yan. "The Parameters Optimization of Rheology Stress Model for Aluminum Based on GA." Advanced Materials Research 314-316 (August 2011): 1300–1305. http://dx.doi.org/10.4028/www.scientific.net/amr.314-316.1300.

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Based on Hyperbolic sine relationship proposed by Sellar and Tegart rheology stress model for high-purity high-temperature plastic deformation of polycrystalline aluminum was constructed by Zenner-Hollomon parameters. Parameters influencing rheology stress of aluminum were optimized，through the initial population identification、selection、crossover、mutation、evaluation and screening, concluding the connection between rheology stress、deformation rate and deformation temperature by GA(genetic algorithm). The results show that GA is feasible, through model validation by experimental data and comparing calculated and experimental results under different deformation rates.

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Sly, Michael K., Arashdeep S. Thind, Rohan Mishra, Katharine M. Flores, and Philip Skemer. "Low-temperature rheology of calcite." Geophysical Journal International 221, no. 1 (December 31, 2019): 129–41. http://dx.doi.org/10.1093/gji/ggz577.

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SUMMARY Low-temperature plastic rheology of calcite plays a significant role in the dynamics of Earth's crust. However, it is technically challenging to study plastic rheology at low temperatures because of the high confining pressures required to inhibit fracturing. Micromechanical tests, such as nanoindentation and micropillar compression, can provide insight into plastic rheology under these conditions because, due to the small scale, plastic deformation can be achieved at low temperatures without the need for secondary confinement. In this study, nanoindentation and micropillar compression experiments were performed on oriented grains within a polycrystalline sample of Carrara marble at temperatures ranging from 23 to 175 °C, using a nanoindenter. Indentation hardness is acquired directly from nanoindentation experiments. These data are then used to calculate yield stress as a function of temperature using numerical approaches that model the stress state under the indenter. Indentation data are complemented by uniaxial micropillar compression experiments. Cylindrical micropillars ∼1 and ∼3 μm in diameter were fabricated using a focused ion beam-based micromachining technique. Yield stress in micropillar experiments is determined directly from the applied load and micropillar dimensions. Mechanical data are fit to constitutive flow laws for low-temperature plasticity and compared to extrapolations of similar flow laws from high-temperature experiments. This study also considered the effects of crystallographic orientation on yield stress in calcite. Although there is a clear orientation dependence to plastic yielding, this effect is relatively small in comparison to the influence of temperature.

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van Batenburg-Sherwood, Joseph, and Stavroula Balabani. "Continuum microhaemodynamics modelling using inverse rheology." Biomechanics and Modeling in Mechanobiology 21, no. 1 (December 14, 2021): 335–61. http://dx.doi.org/10.1007/s10237-021-01537-2.

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AbstractModelling blood flow in microvascular networks is challenging due to the complex nature of haemorheology. Zero- and one-dimensional approaches cannot reproduce local haemodynamics, and models that consider individual red blood cells (RBCs) are prohibitively computationally expensive. Continuum approaches could provide an efficient solution, but dependence on a large parameter space and scarcity of experimental data for validation has limited their application. We describe a method to assimilate experimental RBC velocity and concentration data into a continuum numerical modelling framework. Imaging data of RBCs were acquired in a sequentially bifurcating microchannel for various flow conditions. RBC concentration distributions were evaluated and mapped into computational fluid dynamics simulations with rheology prescribed by the Quemada model. Predicted velocities were compared to particle image velocimetry data. A subset of cases was used for parameter optimisation, and the resulting model was applied to a wider data set to evaluate model efficacy. The pre-optimised model reduced errors in predicted velocity by 60% compared to assuming a Newtonian fluid, and optimisation further reduced errors by 40%. Asymmetry of RBC velocity and concentration profiles was demonstrated to play a critical role. Excluding asymmetry in the RBC concentration doubled the error, but excluding spatial distributions of shear rate had little effect. This study demonstrates that a continuum model with optimised rheological parameters can reproduce measured velocity if RBC concentration distributions are known a priori. Developing this approach for RBC transport with more network configurations has the potential to provide an efficient approach for modelling network-scale haemodynamics.

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La Gatta, Annalisa, Emiliano Bedini, Maria Aschettino, Rosario Finamore, and Chiara Schiraldi. "Hyaluronan Hydrogels: Rheology and Stability in Relation to the Type/Level of Biopolymer Chemical Modification." Polymers 14, no. 12 (June 14, 2022): 2402. http://dx.doi.org/10.3390/polym14122402.

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BDDE (1,4-butanediol-diglycidylether)-crosslinked hyaluronan (HA) hydrogels are widely used for dermo-aesthetic purposes. The rheology and stability of the gels under physiological conditions greatly affect their clinical indications and outcomes. To date, no studies investigating how these features are related to the chemistry of the polymeric network have been reported. Here, four available HA-BDDE hydrogels were studied to determine how and to what extent their rheology and stability with respect to enzymatic hydrolysis relate to the type and degree of HA structural modification. 1H-/13C-NMR analyses were associated for the quantification of the “true” HA chemical derivatization level, discriminating between HA that was effectively crosslinked by BDDE, and branched HA with BDDE that was anchored on one side. The rheology was measured conventionally and during hydration in a physiological medium. Sensitivity to bovine testicular hyaluronidase was quantified. The correlation between NMR data and gel rheology/stability was evaluated. The study indicated that (1) the gels greatly differed in the amounts of branched, crosslinked, and overall modified HA, with most of the HA being branched; (2) unexpectedly, the conventionally measured rheological properties did not correlate with the chemical data; (3) the gels’ ranking in terms of rheology was greatly affected by hydration; (4) the rheology of the hydrated gels was quantitatively correlated with the amount of crosslinked HA, whereas the correlations with the total HA modification level and with the degree of branched HA were less significant; (5) increasing HA derivatization/crosslinking over 9/3 mol% did not enhance the stability with respect to hyaluronidases. These results broaden our knowledge of these gels and provide valuable information for improving their design and characterization.

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Jain, Chhavi, Jun Korenaga, and Shun‐ichiro Karato. "Global Analysis of Experimental Data on the Rheology of Olivine Aggregates." Journal of Geophysical Research: Solid Earth 124, no. 1 (January 2019): 310–34. http://dx.doi.org/10.1029/2018jb016558.

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Bollinger, Caroline, Paul Raterron, Patrick Cordier, and Sébastien Merkel. "Polycrystalline olivine rheology in dislocation creep: Revisiting experimental data to 8.1GPa." Physics of the Earth and Planetary Interiors 228 (March 2014): 211–19. http://dx.doi.org/10.1016/j.pepi.2013.12.001.

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Ratkovich, N., W. Horn, F. P. Helmus, S. Rosenberger, W. Naessens, I. Nopens, and T. R. Bentzen. "Activated sludge rheology: A critical review on data collection and modelling." Water Research 47, no. 2 (February 2013): 463–82. http://dx.doi.org/10.1016/j.watres.2012.11.021.

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Stroh, J. N., Gleb Panteleev, Max Yaremchuk, Oceana Francis, and Richard Allard. "Toward Optimization of Rheology in Sea Ice Models through Data Assimilation." Journal of Atmospheric and Oceanic Technology 36, no. 12 (December 2019): 2365–82. http://dx.doi.org/10.1175/jtech-d-18-0239.1.

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AbstractSea ice models that allow for deformation are primarily based on rheological formulations originally developed in the 1970s. In both the original viscoplastic (VP) and elastic-VP schemes, the internal pressure term is modeled as a function of variable sea ice thickness and concentration with spatially and temporally constant empirical parameters for ice strength. This work considers a spatially variable extension of the rheology parameters as well as wind stress in a one-dimensional VP sea ice data assimilation system. In regions of total ice cover, experiments that assimilate synthetic ice-state observations using variable rheological parameters show larger improvements than equivalent experiments using homogeneous parameters. For partially ice-covered regions where internal ice stresses are relatively unimportant, experiments assimilating synthetic sea ice velocity observations demonstrate reasonable reconstruction of spatially variable wind stresses. These results suggest practical benefits for sea ice–state reconstruction and forecasts by using sea ice velocity, thickness, and concentration observations to optimize spatially varying rheological parameters and to improve wind stress forcing.

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Xu, Yafang, Wei Yu, and Chixing Zhou. "Liquid–liquid phase separation and its effect on the crystallization in polylactic acid/poly(ethylene glycol) blends." RSC Adv. 4, no. 98 (2014): 55435–44. http://dx.doi.org/10.1039/c4ra08985e.

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Beris, Antony N., Jeffrey S. Horner, Soham Jariwala, Matthew J. Armstrong, and Norman J. Wagner. "Recent advances in blood rheology: a review." Soft Matter 17, no. 47 (2021): 10591–613. http://dx.doi.org/10.1039/d1sm01212f.

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Maurin, Raphael, Julien Chauchat, and Philippe Frey. "Dense granular flow rheology in turbulent bedload transport." Journal of Fluid Mechanics 804 (September 9, 2016): 490–512. http://dx.doi.org/10.1017/jfm.2016.520.

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The local granular rheology is investigated numerically in turbulent bedload transport. Considering spherical particles, steady uniform configurations are simulated using a coupled fluid–discrete-element model. The stress tensor is computed as a function of the depth for a series of simulations varying the Shields number, the specific density and the particle diameter. The results are analysed in the framework of the $\unicode[STIX]{x1D707}(I)$ rheology and exhibit a collapse of both the shear to normal stress ratio and the solid volume fraction over a wide range of inertial numbers. Contrary to expectations, the effect of the interstitial fluid on the granular rheology is shown to be negligible, supporting recent work suggesting the absence of a clear transition between the free-fall and turbulent regimes. In addition, data collapse is observed up to unexpectedly high inertial numbers $I\sim 2$, challenging the existing conceptions and parametrisation of the $\unicode[STIX]{x1D707}(I)$ rheology. Focusing upon bedload transport modelling, the results are pragmatically analysed in the $\unicode[STIX]{x1D707}(I)$ framework in order to propose a granular rheology for bedload transport. The proposed rheology is tested using a 1D volume-averaged two-phase continuous model, and is shown to accurately reproduce the dense granular flow profiles and the sediment transport rate over a wide range of Shields numbers. The present contribution represents a step in the upscaling process from particle-scale simulations towards large-scale applications involving complex flow geometry.

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Gray, J. M. N. T., and A. N. Edwards. "A depth-averaged -rheology for shallow granular free-surface flows." Journal of Fluid Mechanics 755 (August 20, 2014): 503–34. http://dx.doi.org/10.1017/jfm.2014.450.

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AbstractThe $\mu (I)$-rheology is a nonlinear viscous law, with a strain-rate invariant and pressure-dependent viscosity, that has proved to be effective at modelling dry granular flows in the intermediate range of the inertial number, $I$. This paper shows how to incorporate the rheology into depth-averaged granular avalanche models. To leading order, the rheology generates an effective basal friction, which is equivalent to a rough bed friction law. A depth-averaged viscous-like term can be derived by integrating the in-plane deviatoric stress through the avalanche depth, using pressure and velocity profiles from a steady-uniform solution to the full $\mu (I)$-rheology. The resulting viscosity is proportional to the thickness to the three halves power, with a coefficient of proportionality that is angle dependent. When substituted into the depth-averaged momentum balance this term generates second-order derivatives of the depth-averaged velocity, which are multiplied by a small parameter. Its inclusion therefore represents a singular perturbation to the equations. It is shown that a granular front propagating down a rough inclined plane is completely unaffected by the rheology, but, discontinuities, which naturally develop in inviscid roll-wave solutions, are smoothed out. By comparison with existing experimental data, it is shown that the depth-averaged $\mu (I)$-rheology accurately predicts the growth rate of spatial instabilities to steady-uniform flow, as well as the dependence of the cutoff frequency on the Froude number and inclination angle. This provides strong evidence that, in the steady-uniform flow regime, the predicted decrease in the viscosity with increasing slope is correct. Outside the range of angles where steady-uniform flows develop, the viscosity becomes negative, which implies that the equations are ill-posed. This is a signature of the ill-posedness of the full $\mu (I)$-rheology at both high and low inertial numbers. The depth-averaged $\mu (I)$-rheology therefore cannot be used outside the valid range of angles without additional regularization.

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Dullaert, Konraad, Gerard van Doremaele, Martin van Duin, and Herman Dikland. "QUANTITATIVE ASSESSMENT OF THE BRANCHING ARCHITECTURE OF EPDM WITH HIGH CONTENT OF 5-VINYL-2-NORBORNENE AS THIRD MONOMER." Rubber Chemistry and Technology 86, no. 4 (December 1, 2013): 503–20. http://dx.doi.org/10.5254/rct.13.87946.

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ABSTRACT The branching architecture of high-molecular-weight EPDM polymers with high amounts of 5-vinyl-2-norbornene (VNB) as a third monomer, produced using recently developed Keltan ACE™ technology, was assessed by means of the dilution rheology method proposed by Crosby et al.1 and compared with conventional Ziegler–Natta EPDM grades. First, the dilution rheology results were converted into a single convenient parameter, called the dilution slope. Next, by combining the dilution rheology results with gel permeation chromatography data and assuming trifunctional branching points, we calculated the volume fraction of the branched polymer, the average molecular weight between branching points, and the branching density. It is shown that the high-VNB polymers studied contained a significantly higher amount of branch-on-branch structures.

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Pedrosa, Camilo, Arild Saasen, Bjørnar Lund, and Jan David Ytrehus. "Wet Drilled Cuttings Bed Rheology." Energies 14, no. 6 (March 16, 2021): 1644. http://dx.doi.org/10.3390/en14061644.

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The cuttings transport efficiency of various drilling fluids has been studied in several approaches. This is an important aspect, since hole cleaning is often a bottleneck in well construction. The studies so far have targeted the drilling fluid cuttings’ transport capability through experiments, simulations or field data. Observed differences in the efficiency due to changes in the drilling fluid properties and compositions have been reported but not always fully understood. In this study, the cuttings bed, wetted with a single drilling fluid, was evaluated. The experiments were performed with parallel plates in an Anton Paar Physica 301 rheometer. The results showed systematic differences in the internal friction behaviors between tests of beds with oil-based and beds with water-based fluids. The observations indicated that cutting beds wetted with a polymeric water-based fluid released clusters of particles when external forces overcame the bonding forces and the beds started to break up. Similarly, it was observed that an oil-based fluid wetted bed allowed particles to break free as single particles. These findings may explain the observed differences in previous cutting transport studies.

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El Omari, Younes, Mohamed Yousfi, Jannick Duchet-Rumeau, and Abderrahim Maazouz. "Recent Advances in the Interfacial Shear and Dilational Rheology of Polymer Systems: From Fundamentals to Applications." Polymers 14, no. 14 (July 13, 2022): 2844. http://dx.doi.org/10.3390/polym14142844.

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The study of the viscoelastic properties of polymer systems containing huge internal two-dimensional interfacial areas, such as blends, foams and multilayer films, is of growing interest and plays a significant role in a variety of industrial fields. Hence, interfacial rheology can represent a powerful tool to directly investigate these complex polymer–polymer interfaces. First, the current review summarizes the theoretical basics and fundamentals of interfacial shear rheology. Particular attention has been devoted to the double-wall ring (DWR), bicone, Du Noüy ring and oscillating needle (ISR) systems. The measurement of surface and interfacial rheological properties requires a consideration of the relative contributions of the surface stress arising from the bulk sub-phases. Here, the experimental procedures and methodologies used to correct the numerical data are described considering the viscoelastic nature of the interface. Second, the interfacial dilational rheology is discussed, starting with the theory and underlying principles. In particular, the Langmuir trough method, the oscillating spinning drop technique and the oscillating pendant drop technique are investigated. The major pioneering studies and latest innovations dedicated to interfacial rheology in both shear and dilatation–compression are highlighted. Finally, the major challenges and limits related to the development of high-temperature interfacial rheology at the molten state are presented. The latter shows great potential for assessing the interfaces of polymer systems encountered in many high-value applications.

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Toyoda, Takahiro, Nariaki Hirose, L. Shogo Urakawa, Hiroyuki Tsujino, Hideyuki Nakano, Norihisa Usui, Yosuke Fujii, Kei Sakamoto, and Goro Yamanaka. "Effects of Inclusion of Adjoint Sea Ice Rheology on Backward Sensitivity Evolution Examined Using an Adjoint Ocean–Sea Ice Model." Monthly Weather Review 147, no. 6 (May 23, 2019): 2145–62. http://dx.doi.org/10.1175/mwr-d-18-0198.1.

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Abstract As part of the ongoing development of an ocean data assimilation system for operational ocean monitoring and seasonal prediction, an adjoint sea ice model was developed that incorporates sea ice rheology, which was omitted from previously developed adjoint models to avoid model instability. The newly developed adjoint model was merged with the existing system to construct a global ocean–sea ice adjoint model. A series of sensitivity experiments, in which idealized initial values were given for the adjoint sea ice area fraction and thickness, were conducted, with particular attention to the differences between the cases with free-drift approximation in the adjoint sea ice model as in previous studies and with full sea ice dynamics including rheology. The internal stress effects represented in the adjoint rheology induced remarkable differences in the evolution of the initialized and generated adjoint variables, such as for the sea ice velocity by O(102) in magnitude, which highlighted the importance of the adjoint rheology in the central Arctic Ocean. In addition, sensitivities with respect to the nonprognostic variables associated with the sea ice dynamics were obtained only through the adjoint rheology. These results suggested a potential for providing an improved global atmosphere–ocean–sea ice state estimation through a four-dimensional variational approach with the adjoint sea ice model as developed in this study.

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Gowida, Ahmed, Salaheldin Elkatatny, Emad Ramadan, and Abdulazeez Abdulraheem. "Data-Driven Framework to Predict the Rheological Properties of CaCl2 Brine-Based Drill-in Fluid Using Artificial Neural Network." Energies 12, no. 10 (May 17, 2019): 1880. http://dx.doi.org/10.3390/en12101880.

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Calcium chloride brine-based drill-in fluid is commonly used within the reservoir section, as it is specially formulated to maximize drilling experience, and to protect the reservoir from being damaged. Monitoring the drilling fluid rheology including plastic viscosity, P V , apparent viscosity, A V , yield point, Y p , flow behavior index, n , and flow consistency index, k , has great importance in evaluating hole cleaning and optimizing drilling hydraulics. Therefore, it is very crucial for the mud rheology to be checked periodically during drilling, in order to control its persistent change. Such properties are often measured in the field twice a day, and in practice, this takes a long time (2–3 h for taking measurements and cleaning the instruments). However, mud weight, M W , and Marsh funnel viscosity, M F , are periodically measured every 15–20 min. The objective of this study is to develop new models using artificial neural network, ANN, to predict the rheological properties of calcium chloride brine-based mud using M W and M F measurements then extract empirical correlations in a white-box mode to predict these properties based on M W and M F . Field measurements, 515 points, representing actual mud samples, were collected to build the proposed ANN models. The optimized parameters of these models resulted in highly accurate results indicated by a high correlation coefficient, R, between the predicted and measured values, which exceeded 0.97, with an average absolute percentage error, AAPE, that did not exceed 6.1%. Accordingly, the developed models are very useful for monitoring the mud rheology to optimize the drilling operation and avoid many problems such as hole cleaning issues, pipe sticking and loss of circulation.

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Chandrasekar, Pavan, Anjala Nourin, Addepalli Sri Naga Bhushana Aravind Gupta, Bavineni Venkata Jyoshna, and Dhanya Sathyan. "Modelling the Yield Stress of Fly-Ash Added Superplasticized Cement Paste at Different Temperatures Using Artificial Neural Network." Materials Science Forum 1048 (January 4, 2022): 366–75. http://dx.doi.org/10.4028/www.scientific.net/msf.1048.366.

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Abstract: Rheology is the science that concerns the flow of liquids, and the distortion of solids under an applied force. The study of the rheology of concrete determines the properties of fresh concrete. The rheological parameters are affected by temperature, stress conditions and several other factors. The main intention of this research is to model the rheological parameters of the fly ash incorporated cement with various types of superplasticizers exposed under different temperatures using an Artificial Neural Network. Test data were generated by performing rheological tests on cement paste at three distinct temperatures (15, 27, 35°C). Mixes were prepared using OPC, fly ash (15, 25, 35%) and superplasticizers of four different families. By conducting experiments, 252 data have been generated by modifying the combination of fly-ash, superplasticizer, and test temperature. Among the 252 data, 80% has been utilized for training and 20% is utilized for predicting the model’s accuracy. The input layer of the model consists of test temperature, the amount of fly ash replaced, cement and water content, and four different groups of superplasticizers. The cement paste’s yield stress was the output parameter of the model. The model generated data has been compared with the experimentally generated data to determine the accuracy of the model.Keywords: Rheology, Fly Ash, Superplasticizer, Temperature, ANN

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Pople, J. A., G. R. Mitchell, and C. K. Chai. "Real Time X-Ray Rheology of Polymers." Advances in X-ray Analysis 38 (1994): 531–37. http://dx.doi.org/10.1154/s037603080001819x.

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The ability to prcbe the structure of a polymer during deformation is of considerable technological interest as it lends an insight into the mechanisms involved in polymer processing. The behaviour of Liquid Crystalline Polymers (LCP's) during shear flow has generated much experimental interest by virtue of their unusual behaviour compared to that of simpler polymeric melts. The theory developed by Doi attempts to explain the observed phenomena in terms of considering interactions of rigid-rods Exact solutions to the Doi theory have been compared to experimental procedures using lyotropic LCP systems. Although much of the available data relates to mechanical measurements, the comparisons with quantitative structural data can provide useful insight.

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Unsworth, M. J., A. G. Jones, W. Wei, G. Marquis, S. G. Gokarn, and J. E. Spratt. "Crustal rheology of the Himalaya and Southern Tibet inferred from magnetotelluric data." Nature 438, no. 7064 (November 2005): 78–81. http://dx.doi.org/10.1038/nature04154.

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Jacobsen, Jørgen Gausdal, Behruz Shaker Shiran, Tormod Skauge, Kenneth Stuart Sorbie, and Arne Skauge. "Qualification of New Methods for Measuring In Situ Rheology of Non-Newtonian Fluids in Porous Media." Polymers 12, no. 2 (February 14, 2020): 452. http://dx.doi.org/10.3390/polym12020452.

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Pressure drop (ΔP) versus volumetric injection rate (Q) data from linear core floods have typically been used to measure in situ rheology of non-Newtonian fluids in porous media. However, linear flow is characterized by steady-state conditions, in contrast to radial flow where both pressure and shear-forces have non-linear gradients. In this paper, we qualify recently developed methods for measuring in situ rheology in radial flow experiments, and then quantitatively investigate the robustness of these methods against pressure measurement error. Application of the new methods to experimental data also enabled accurate investigation of memory and rate effects during polymer flow through porous media. A radial polymer flow experiment using partially hydrolyzed polyacrylamide (HPAM) was performed on a Bentheimer sandstone disc where pressure ports distributed between a central injector and the perimeter production line enabled a detailed analysis of pressure variation with radial distance. It has been suggested that the observed shear-thinning behavior of HPAM solutions at low flux in porous media could be an experimental artifact due to the use of insufficiently accurate pressure transducers. Consequently, a generic simulation study was conducted where the level of pressure measurement error on in situ polymer rheology was quantitatively investigated. Results clearly demonstrate the robustness of the history match methods to pressure measurement error typical for radial flow experiments, where negligible deviations from the reference rheology was observed. It was not until the error level was increased to five-fold of typical conditions that significant deviation from the reference rheology emerged. Based on results from pore network modelling, Chauveteau (1981) demonstrated that polymer flow in porous media may at some rate be influenced by the prior history. In this paper, polymer memory effects could be evaluated at the Darcy scale by history matching the pressure drop between individual pressure ports and the producer as a function of injection rate (conventional method). Since the number of successive contraction events increases with radial distance, the polymer has a different pre-history at the various pressure ports. Rheology curves obtained from history matching the radial flow experiment were overlapping, which shows that there is no influence of geometry on in-situ rheology for the particular HPAM polymer investigated. In addition, the onset of shear-thickening was independent of volumetric injection rate in radial flow.

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Hooke, Roger LeB, Brian Hanson, Neal R. Iverson, Peter Jansson, and Urs H. Fischer. "Rheology of till beneath Storglaciären, Sweden." Journal of Glaciology 43, no. 143 (1997): 172–79. http://dx.doi.org/10.3189/s0022143000002938.

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AbstractIn order to study, in situ, the rheology of a deforming subglacial till, various instruments were emplaced in till beneath Storglaciären, Sweden. Boreholes were used to gain access to the till beneath about 100 m of ice. Tiltmeters provided an estimate of the shear strain rate in the till. Two other instruments yielded measures of till strength. In addition, water pressures were recorded in boreholes and in the till, a computer-controlled distance meter provided an effectively continuous record of the surface velocity and data from frequent surveys of a stake network were used to estimate the mean basal drag, based on a force-balance calculation.Tilt rates varied directly with effective pressure, so decreases in water pressure apparently increased the coupling between the glacier and the bed. Surface speed was either out of phase with tilt or varied independently of tilt. Thus, increases in speed were apparently a consequence either of longitudinal coupling or of reduced coupling between the glacier and the bed; they were not a result of till deformation! Till strength varied directly with effective pressure, which is consistent with it being a Mohr – Coulomb, or frictional material. The devices measuring till strength are presumed to have been pulled through the till at a speed that varied in phase with the surface speed but till strength did not vary systematically with surface speed. This implies that the residual strength of the till is insensitive to strain rate. Thus, the appropriate constitutive equation for till rheology may be of the form:where k is a constant. This is consistent with experimental data reported in the geotechnical literature.

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Hooke, Roger LeB, Brian Hanson, Neal R. Iverson, Peter Jansson, and Urs H. Fischer. "Rheology of till beneath Storglaciären, Sweden." Journal of Glaciology 43, no. 143 (1997): 172–79. http://dx.doi.org/10.1017/s0022143000002938.

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AbstractIn order to study, in situ, the rheology of a deforming subglacial till, various instruments were emplaced in till beneath Storglaciären, Sweden. Boreholes were used to gain access to the till beneath about 100 m of ice. Tiltmeters provided an estimate of the shear strain rate in the till. Two other instruments yielded measures of till strength. In addition, water pressures were recorded in boreholes and in the till, a computer-controlled distance meter provided an effectively continuous record of the surface velocity and data from frequent surveys of a stake network were used to estimate the mean basal drag, based on a force-balance calculation.Tilt rates varied directly with effective pressure, so decreases in water pressure apparently increased the coupling between the glacier and the bed. Surface speed was either out of phase with tilt or varied independently of tilt. Thus, increases in speed were apparently a consequence either of longitudinal coupling or of reduced coupling between the glacier and the bed;they were not a result of till deformation!Till strength varied directly with effective pressure, which is consistent with it being a Mohr – Coulomb, or frictional material. The devices measuring till strength are presumed to have been pulled through the till at a speed that varied in phase with the surface speed but till strength did not vary systematically with surface speed. This implies that the residual strength of the till is insensitive to strain rate. Thus, the appropriate constitutive equation for till rheology may be of the form:wherekis a constant. This is consistent with experimental data reported in the geotechnical literature.

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MINCHEW, BRENT M., COLIN R. MEYER, ALEXANDER A. ROBEL, G. HILMAR GUDMUNDSSON, and MARK SIMONS. "Processes controlling the downstream evolution of ice rheology in glacier shear margins: case study on Rutford Ice Stream, West Antarctica." Journal of Glaciology 64, no. 246 (June 7, 2018): 583–94. http://dx.doi.org/10.1017/jog.2018.47.

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ABSTRACTIce rheology governs how glaciers flow and respond to environmental change. The rheology of glacier ice evolves in response to a variety of mechanisms, including damage, heating, melting and the development of crystalline fabric. The relative contributions of these rheological mechanisms are not well understood. Using remotely sensed data and physical models, we decouple the influence of each of the aforementioned mechanisms along the margins of Rutford Ice Stream, a laterally confined outlet glacier in West Antarctica. We show that fabric is an important control on ice rheology in the shear margins, with an inferred softening effect consistent with a single-maximum fabric. Fabric evolves to steady state near the onset of streaming flow, and ice progressively softens downstream almost exclusively due to shear heating. The rate of heating is sensitive to local shear strain rates, which respond to local changes in bed topography as ice is squeezed through the basal trough. The impact of shear heating on the downstream evolution of ice rheology in a laterally confined glacier suggests that the thermoviscous feedback – wherein faster ice flow leads to higher rates of shear heating, further softening the ice – is a fundamental control on glacier dynamics.

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Mukhopadhyay, Anal K., and Sehoon Jang. "Predicting Cement–Admixture Incompatibilities with Cement Paste Rheology." Transportation Research Record: Journal of the Transportation Research Board 2290, no. 1 (January 2012): 19–29. http://dx.doi.org/10.3141/2290-03.

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The complex interaction between cement and the chemical and mineral admixtures in concrete mixture sometimes causes unpredictable concrete performance in the field, generally defined as concrete incompatibilities. Cement paste rheology measurements—rather than traditional workability tests—can effectively detect these incompatibilities in concrete before the concrete is placed to avoid setting-time, workability, and curing-related issues, which sometimes lead to early-age cracking, especially in severe weather conditions. The objective of the present study is to examine the applicability of the Superpave® dynamic shear rheometer to measure cement paste rheology and to identify incompatibilities between cement and the admixtures based on cement paste rheological behavior. Extensive laboratory investigation showed that dynamic shear rheometer in modified form could measure cement paste rheology with permissible repeatability and sensitivity and has great potential in identifying the incompatibilities between cement and the admixtures. Heat of hydration data from an isothermal calorimeter test and the setting time results of the mixtures studied have strongly supported the rheology results. A procedure to formulate the rheology-based acceptance criteria has been developed on the basis of the available test results. Further refinement of these acceptance criteria based on detailed work covering a wide range of incompatibilities and validation through a round-robin testing program is warranted. This research will ultimately help concrete producers and district laboratories detect problematic combinations of concrete ingredients during the mixture design process.

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Itoh, T., S. Chien, and S. Usami. "Deformability measurements on individual sickle cells using a new system with pO2 and temperature control." Blood 79, no. 8 (April 15, 1992): 2141–47. http://dx.doi.org/10.1182/blood.v79.8.2141.2141.

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Abstract Although the rheologic behavior of sickle erythrocytes (SS cells) is highly dependent on oxygen tension (pO2) and temperature, very little data exist regarding the effects of deoxygenation and reoxygenation on the rheology of “individual” SS cells at body temperature. We have devised and assessed a new experiment system, in which micropipette aspiration can be performed on individual cells in a constant- temperature chamber that has ports for changing media with different pO2 (effected in 30 to 120 seconds) and sensing probes for monitoring pO2 and temperature. This system enabled us to simultaneously alter and monitor pO2 at 37 +/- 0.5 degrees C, and to monitor and study a single cell under microscopic observation. The static rigidity (E) and dynamic rigidity (eta) of individual SS cells were determined by repeated aspirations of the same cell under various pO2. With stepwise reductions in pO2, E and eta showed no significant changes before sickling, but once sickled, their values markedly increased by 10(2)- to 10(3)-fold concomitantly with morphologic alteration of the cell. Thus, the deformability of a single SS cell behaves in an “all or none” manner at a critical pO2, and earlier studies on the effect of deoxygenation on the rheology of SS cell suspensions probably reflect the overall behavior of SS cells with widely distributed critical pO2.

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40

Itoh, T., S. Chien, and S. Usami. "Deformability measurements on individual sickle cells using a new system with pO2 and temperature control." Blood 79, no. 8 (April 15, 1992): 2141–47. http://dx.doi.org/10.1182/blood.v79.8.2141.bloodjournal7982141.

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Although the rheologic behavior of sickle erythrocytes (SS cells) is highly dependent on oxygen tension (pO2) and temperature, very little data exist regarding the effects of deoxygenation and reoxygenation on the rheology of “individual” SS cells at body temperature. We have devised and assessed a new experiment system, in which micropipette aspiration can be performed on individual cells in a constant- temperature chamber that has ports for changing media with different pO2 (effected in 30 to 120 seconds) and sensing probes for monitoring pO2 and temperature. This system enabled us to simultaneously alter and monitor pO2 at 37 +/- 0.5 degrees C, and to monitor and study a single cell under microscopic observation. The static rigidity (E) and dynamic rigidity (eta) of individual SS cells were determined by repeated aspirations of the same cell under various pO2. With stepwise reductions in pO2, E and eta showed no significant changes before sickling, but once sickled, their values markedly increased by 10(2)- to 10(3)-fold concomitantly with morphologic alteration of the cell. Thus, the deformability of a single SS cell behaves in an “all or none” manner at a critical pO2, and earlier studies on the effect of deoxygenation on the rheology of SS cell suspensions probably reflect the overall behavior of SS cells with widely distributed critical pO2.

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Mueller, S., E. W. Llewellin, and H. M. Mader. "The rheology of suspensions of solid particles." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 466, no. 2116 (December 16, 2009): 1201–28. http://dx.doi.org/10.1098/rspa.2009.0445.

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We present data for the rheology of suspensions of monodisperse particles of varying aspect ratio, from oblate to prolate, and covering particle volume fractions ϕ from dilute to highly concentrated. Rheology is characterized by fitting the experimental data to the model of Herschel & Bulkley (Herschel & Bulkley 1926 Kolloid Z. 39 , 291–300 ( doi:10.1007/BF01432034 )) yielding three rheometric parameters: consistency K (cognate with viscosity); flow index n (a measure of shear-thinning); yield stress τ 0 . The consistency K of suspensions of particles of arbitrary aspect ratio can be accurately predicted by the model of Maron & Pierce (Maron & Pierce 1956 J. Colloid Sci. 11 , 80–95 ( doi:10.1016/0095-8522(56)90023-X )) with the maximum packing fraction ϕ m as the only fitted parameter. We derive empirical relationships for ϕ m and n as a function of average particle aspect ratio r p and for τ 0 as a function of ϕ m and a fitting parameter τ *. These relationships can be used to predict the rheology of suspensions of prolate particles from measured ϕ and r p . By recasting our data in terms of the Einstein coefficient, we relate our rheological observations to the underlying particle motions via Jeffery’s (Jeffery 1922 Proc. R. Soc. Lond. A 102 , 161–179 ( doi:10.1098/rspa.1922.0078 )) theory. We extend Jeffery’s work to calculate, numerically, the Einstein coefficient for a suspension of many, initially randomly oriented particles. This provides a physical, microstructural explanation of our observations, including transient oscillations seen during run start-up and changes of rheological regime as ϕ increases.

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Kogan, Viktor Vladimirovich, and Larisa Eduardovna Semenova. "Engineering rheology in food industry." Vestnik of Astrakhan State Technical University. Series: Fishing industry 2019, no. 4 (December 13, 2019): 147–56. http://dx.doi.org/10.24143/2073-5529-2019-4-147-156.

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The paper describes the technological processes of the food industry assuring production of a finished product with predetermined properties, where different types of food raw materials and semi-finished products are objects of study of engineering rheology, considering their be-havior at the stage of deformation (compression, twisting, stretching). The processes of mixing and inter-operational transportation of products are interrelated with the viscous-plastic raw materials (dough, minced meat, candy mass) contacting with the working parts of machines. That is why, in order to rationally use and save material resources the selection of process parameters and operating modes should be carried out subject to the rheological properties of the products (shearing, surface, volumetric). These properties have been listed and their nature has been described. The basic shearing characteristics of the raw materials under study have been determined and analyzed. Specific features of the elastic, viscous and plastic properties of the product under stress are considered. The combinations of rheological models of simple idealized bodies are studied: viscous-plastic, elastic-plastic. Equations that describe the flow of various viscous-plastic media are given. The dependence of the effective viscosity on the stress or shear rate for meatball meat from fish is graphically presented. The effect of minced meat humidity on the structural and mechanical properties of meatballs from fresh carp, pike, catfish, and bream has been traced. Rheological characteristics were determined by a rotational viscometer RV-8. Samples were prepared for one specimen from each product by adding a different amount of water, followed by stirring and thermostating. In parallel, the fat content was determined. According to the obtained values of structural and mechanical characteristics, the rheological properties of meatballs have been illustrated in a wide range of variables. From the data obtained it can be inferred that with increasing humidity, the numerical values of all shearing characteristics decrease due to thickening of the liquid interlayers between the product particles, and the rate of the mechanical structure remains practically unchanged.

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Feng, Guohong, Zhi Hu, He Ma, Tiantian Bai, Yabing Guo, and Yiran Hao. "Semi-solid rheology characterization of sludge conditioned with inorganic coagulants." Water Science and Technology 80, no. 11 (December 1, 2019): 2158–68. http://dx.doi.org/10.2166/wst.2020.022.

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Abstract Rheology measurement, a state-of-the-art technology in a multitude of engineering disciplines, has often been used for computational fluid dynamic simulation of wastewater treatment processes, especially in anaerobic digestion and dewatering. In this work, rheological tests were used to study the semi-solid characteristics of sludge and a good result was obtained. The inorganic coagulants polyaluminum chloride (PAC) and ferric chloride (FC) both increased the floc strength of sludge, leading to higher rheology parameters such as elastic modulus, viscous modulus and specific thixotropy area. Curiously, the shape of all rheological curves exhibited little change with increasing coagulant dosage. The results indicated that various physical and chemical actions among coagulants and sludge flocs relate only to rigid structure, not to the nature of rheology behavior. Frequency sweep tests clearly showed that elastic modulus was a logarithmic function of frequency, suggesting that sludge could not properly be called a soft material due to its inorganic particles. An improved viscoelastic model was successfully developed to predict the experimental data of creep and recovery tests in the linear viscoelastic region. Furthermore, complicated viscoelastic behavior of sludge was also observed, and all the rheology tests could provide the optimum dosage of PAC but not the optimum dosage of FC.

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Meyer, Colin R., Kaitlin M. Keegan, Ian Baker, and Robert L. Hawley. "A model for French-press experiments of dry snow compaction." Cryosphere 14, no. 5 (May 5, 2020): 1449–58. http://dx.doi.org/10.5194/tc-14-1449-2020.

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Abstract. Snow densification stores water in alpine regions and transforms snow into ice on the surface of glaciers. Despite its importance in determining snow-water equivalent and glacier-induced sea level rise, we still lack a complete understanding of the physical mechanisms underlying snow compaction. In essence, compaction is a rheological process, where the rheology evolves with depth due to variation in temperature, pressure, humidity, and meltwater. The rheology of snow compaction can be determined in a few ways, for example, through empirical investigations (e.g., Herron and Langway, 1980), by microstructural considerations (e.g., Alley, 1987), or by measuring the rheology directly, which is the approach we take here. Using a French-press or cafetière-à-piston compression stage, Wang and Baker (2013) compressed numerous snow samples of different densities. Here we derive a mixture theory for compaction and airflow through the porous snow to compare against these experimental data. We find that a plastic compaction law explains experimental results. Taking standard forms for the permeability and effective pressure as functions of the porosity, we show that this compaction mode persists for a range of densities and overburden loads. These findings suggest that measuring compaction in the lab is a promising direction for determining the rheology of snow through its many stages of densification.

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Turpeinen, Tuomas, Ari Jäsberg, Sanna Haavisto, Johanna Liukkonen, Juha Salmela, and Antti I. Koponen. "Pipe rheology of microfibrillated cellulose suspensions." Cellulose 27, no. 1 (October 19, 2019): 141–56. http://dx.doi.org/10.1007/s10570-019-02784-4.

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Abstract The shear rheology of two mechanically manufactured microfibrillated cellulose (MFC) suspensions was studied in a consistency range of 0.2–2.0% with a pipe rheometer combined with ultrasound velocity profiling. The MFC suspensions behaved at all consistencies as shear thinning power law fluids. Despite their significantly different particle size, the viscous behavior of the suspensions was quantitatively similar. For both suspensions, the dependence of yield stress and the consistency index on consistency was a power law with an exponent of 2.4, similar to some pulp suspensions. The dependence of flow index on consistency was also a power law, with an exponent of − 0.36. The slip flow was very strong for both MFCs and contributed up to 95% to the flow rate. When wall shear stress exceeded two times the yield stress, slip flow caused drag reduction with consistencies higher than 0.8%. When inspecting the slip velocities of both suspensions as a function of wall shear stress scaled with the yield stress, a good data collapse was obtained. The observed similarities in the shear rheology of both the MFC suspensions and the similar behavior of some pulp fiber suspensions suggests that the shear rheology of MFC suspensions might be more universal than has previously been realized.

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ORPE, ASHISH V., and D. V. KHAKHAR. "Rheology of surface granular flows." Journal of Fluid Mechanics 571 (January 4, 2007): 1–32. http://dx.doi.org/10.1017/s002211200600320x.

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Surface granular flow, comprising granular material flowing on the surface of a heap of the same material, occurs in several industrial and natural systems. The rheology of such a flow was investigated by means of measurements of velocity and number-density profiles in a quasi-two-dimensional rotating cylinder, half-filled with a model granular material – monosize spherical stainless-steel particles. The measurements were made at the centre of the cylinder, where the flow is fully developed, using streakline photography and image analysis. The stress profile was computed from the number-density profile using a force balance which takes into account wall friction. Mean-velocity and root-mean-square (r.m.s.)-velocity profiles are reported for different particle sizes and cylinder rotation speeds. The profiles for the mean velocity superimpose when distance is scaled by the particle diameterdand velocity by a characteristic shear rate$\dot{\gamma}_C = [g\sin(\beta_m-\beta_s)/d\cos\beta_s]^{1/2}$and the particle diameter, where βmis the maximum dynamic angle of repose and βsis the static angle of repose. The maximum dynamic angle of repose is found to vary with the local flow rate. The scaling is also found to work for the r.m.s. velocity profiles. The mean velocity is found to decay exponentially with depth in the bed, with decay length λ = 1.1d. The r.m.s. velocity shows similar behaviour but with λ = 1.7d. The r.m.s. velocity profile shows two regimes: near the free surface the r.m.s. velocity is nearly constant and below a transition point it decays linearly with depth. The shear rate, obtained by numerical differentiation of the velocity profile, is not constant anywhere in the layer and has a maximum which occurs at the same depth as the transition in the r.m.s. velocity profile. Above the transition point the velocity distributions are Gaussian and below the transition point the velocity distributions gradually approach a Poisson distribution. The shear stress increases roughly linearly with depth. The variation in the apparent viscosity η with r.m.s. velocityushows a relatively sharp transition at the shear-rate maximum, and in the region below this point the apparent viscosity η ∼u−1.5. The measurements indicate that the flow comprises two layers: an upper low-viscosity layer with a nearly constant r.m.s. velocity and a lower layer of increasing viscosity with a decreasing r.m.s. velocity. The thickness of the upper layer depends on the local flow rate and is independent of particle diameter while the reverse is found to hold for the lower-layer thickness. The experimental data is compared with the predictions of three models for granular flow.

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Hsiao, Hsing-Sen S., Bharat Bhushan, and Bernard J. Hamrock. "Ultrathin Liquid Lubrication of Magnetic Head–Rigid Disk Interface for Near-Contact Recording: Part II—Shear Thinning and Thermal Thinning." Journal of Tribology 118, no. 2 (April 1, 1996): 396–401. http://dx.doi.org/10.1115/1.2831315.

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The Carreau shear thinning equation and the modified Roelands thermal thinning equation are combined by using the generalized master curve approach to construct a new thermal non-Newtonian rheology model. The Newton-Raphson method is then used to curve-fit existing experimental data for two perfluoropolyethers to this new model. The thermophysical properties thus found are then used to calculate thermal and shear thinning correction factors for the ultrathin liquid lubrication of magnetic head-rigid disk interfaces. The results of rheology modeling show excellent fits of the widely ranging raw data with the new thermal non-Newtonian model. The results of hydrodynamic analysis indicate that the friction force-isothermal Newtonian shear stress curve for these interfaces is simply a lubricant characteristic curve of thermal-shear thinning.

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Persson, S. U., G. Wohlfart, H. Larsson, and A. Gustafson. "Correlations between fatty acid composition of the erythrocyte membrane and blood rheology data." Scandinavian Journal of Clinical and Laboratory Investigation 56, no. 2 (January 1996): 183–90. http://dx.doi.org/10.3109/00365519609088606.

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Dong, Hao, Wenbo WEI, Sheng Jin, Gaofeng Ye, Jianen Jing, Letian Zhang, Chengliang Xie, and Yaotian Yin. "Understanding Surface Deformation in the Central Tibetan Plateau: Rheology Constrains from Magnetotelluric Data." Acta Geologica Sinica - English Edition 93, S1 (May 2019): 41. http://dx.doi.org/10.1111/1755-6724.13922.

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Lennon, Kyle R., Michela Geri, Gareth H. McKinley, and James W. Swan. "Medium amplitude parallel superposition (MAPS) rheology. Part 2: Experimental protocols and data analysis." Journal of Rheology 64, no. 5 (September 2020): 1263–93. http://dx.doi.org/10.1122/8.0000104.

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Journal articles on the topic 'Rheology data'

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