Rheological behavior of an artificial synovial fluid – influence of temperature, shear rate and pressure

2021 ◽  
Vol 115 ◽  
pp. 104278
Author(s):  
Benedict Rothammer ◽  
Max Marian ◽  
Florian Rummel ◽  
Stefan Schroeder ◽  
Maximilian Uhler ◽  
...  
Keyword(s):  
Shear Rate ◽  
Synovial Fluid ◽  
Rheological Behavior ◽  
Influence Of Temperature ◽  
Temperature Shear

Flow Behaviors of High Acyl Gellan Aqueous Solutions as Affected by Temperature, and Calcium and Gellan Concentrations

2008 ◽  
Vol 4 (5) ◽  
Author(s):  
Yiqun Huang ◽  
Pawan Singh Takhar ◽  
Juming Tang ◽  
Barry G Swanson
Keyword(s):  
Shear Rate ◽  
Aqueous Solutions ◽  
Apparent Viscosity ◽  
Flow Resistance ◽  
Effect Of Temperature ◽  
Temperature Changes ◽  
Influence Of Temperature ◽  
Rheological Behaviors ◽  
Low Concentrations ◽  
Influence Of Temperature On

Rheological behaviors of high acyl (HA) gellan are not well understood partially because of its relatively late commercialization compared to low acyl gellan. The objective of this study was to investigate the effect of temperature (5-30 °C), calcium (0, 1 and 10 mM) and gellan concentrations (0.0044-0.1000% w/v) on the flow behaviors of high acyl gellan aqueous solutions using rheological tests. Gellan solutions with 0 or 1 mM added Ca++ exhibited shear thinning behavior at gellan concentrations above 0.0125%. The influence of temperature on apparent viscosity (shear rate, 100 s-1) of gellan solutions can be described with an Arrhenius relationship. The apparent viscosity of gellan solution at low concentrations was more sensitive to temperature changes. The addition of Ca++ led to a decrease in flow resistance for a dilute gellan solution (<0.0125%), but an increased resistance for a relatively concentrated gellan solution (>0.0125%).

Modeling of Shear Rheological Behavior of Uncured Rubber Melt

2020 ◽  
Vol 30 (1) ◽  
pp. 130-137
Author(s):  
Hengxiao Yang ◽  
Qimian Mo ◽  
Hengyu Lu ◽  
Shixun Zhang ◽  
Wei Cao ◽  
...  
Keyword(s):  
Shear Rate ◽  
Constitutive Model ◽  
Incompressible Fluid ◽  
Rheological Behavior ◽  
Rheological Characteristics ◽  
One Dimensional ◽  
Ptt Model ◽  
Rate Region ◽  
Proposed Model ◽  
Rheological Experiments

AbstractTo describe uncured rubber melt flow, a modified Phan–Thien–Tanner (PTT) model was proposed to characterize the rheological behavior and a viscoelastic one-dimensional flow theory was established in terms of incompressible fluid. The corresponding numerical method was constructed to determine the solution. Rotational rheological experiments were conducted to validate the proposed model. The influence of the parameters in the constitutive model was investigated by comparing the calculated and experimental viscosity to determine the most suitable parameters. The uncured rubber viscosity was 3–4 orders larger than that of plastic and did not have a visible Newtonian region. Compared with the Cross-Williams-Landel-Ferry (Cross-WLF) and original PTT models, the modified PTT model can describe the rheological characteristics in the entire shear-rate region if the parameters are set correctly.

Investigation on the Rheological Behavior of Polyamide6/Montmorillonite Nanocomposites by Reactive Extrusion

2011 ◽  
Vol 233-235 ◽  
pp. 1998-2001 ◽  
Author(s):  
Ming Zhao ◽  
Xiao Zhong Lu ◽  
Kai Gu ◽  
Xiao Min Sun ◽  
Chang Qing Ji
Keyword(s):  
Activation Energy ◽  
Shear Stress ◽  
Shear Rate ◽  
Rheological Behavior ◽  
Reactive Extrusion ◽  
Shear Thinning ◽  
Experimental Results ◽  
Montmorillonite Nanocomposites

The rheological behavior of PA6/montmorillonite(MMT) by reactive extrusion was investigated using cone-and-plate rheometer. The experimental results indicated that PA6/MMT exhibited shear-thinning behavior. The shear stress of both neat PA6 and PA6/MMT increased with the increase in the shear rate. The reduction of the viscous activation energy with the increase of shear stress reflected PA6/MMT can be processed over a wider temperature.

Rheological behavior of SAN/PC blends under extremely high shear rate

1989 ◽  
Vol 37 (7) ◽  
pp. 1837-1853 ◽  
Author(s):  
Hideroh Takahashi ◽  
Takaaki Matsuoka ◽  
Takashi Ohta ◽  
Kenzo Fukumori ◽  
Toshio Kurauchi ◽  
...  
Keyword(s):  
Shear Rate ◽  
Rheological Behavior ◽  
High Shear Rate ◽  
High Shear

scholarly journals An Experimental Study on Human Milk Rheology: Behavior Changes from External Factors

Fluids ◽  
2020 ◽  
Vol 5 (2) ◽  
pp. 42 ◽  
Author(s):  
Diana Alatalo ◽  
Fatemeh Hassanipour
Keyword(s):  
Experimental Study ◽  
Shear Rate ◽  
Human Milk ◽  
Rheological Behavior ◽  
Tube Feeding ◽  
External Factors ◽  
Behavior Changes ◽  
Nutrient Losses ◽  
Thixotropic Behavior ◽  
Temperature Storage

The influence of external factors, including temperature, storage, aging, time, and shear rate, on the general rheological behavior of raw human milk is investigated. Rotational and oscillatory experiments were performed. Human milk showed non-Newtonian, shear-thinning, thixotropic behavior with both yield and flow stresses. Storage and aging increased milk density and decreased viscosity. In general, increases in temperature lowered density and viscosity with periods of inconsistent behavior noted between 6–16 ∘ C and over 40 ∘ C. Non-homogeneous breakdown between the yield and flow stresses was found which, when coupled with thixotropy, helps identify the source of nutrient losses during tube feeding.

Rheological properties of cholesteric liquid crystals as lubricant additives

2019 ◽  
Vol 33 (05) ◽  
pp. 1950014 ◽  
Author(s):  
A. Bindu Madhavi ◽  
S. Sreehari Sastry
Keyword(s):  
Shear Rate ◽  
Rheological Properties ◽  
Loss Modulus ◽  
Flow Behavior ◽  
Lubricant Additives ◽  
Rheological Parameters ◽  
Practical Applications ◽  
Phase Transition Temperatures ◽  
Frequency Independent ◽  
Temperature Shear

Rheological properties of Cholesteryl n-valerate, Cholesteryl decanoate and Cholesteryl myristate which are esters of cholesterol have been studied. Phase transition temperatures and rheological parameters such as viscosity, elastic modulus G[Formula: see text], loss modulus G[Formula: see text] as functions of temperature, shear rate and time are investigated. In frequency sweep test, a higher transition crossover region has occurred for Cholesteryl myristate, whereas for Cholesteryl n-valerate a frequency-independent plateau prevailed for both the moduli. The occurrence of blue phase in Cholesteryl decanoate during temperature sweep measurements is an indication for the rheological support. The results for steady state have informed that cholesteric esters are having non-Newtonian flow behavior in their respective cholesteric phases. The power-law model has explained well the shear rate dependence of shear stress. A few practical applications of these esters as lubricant additives are discussed, too.

Utilizing macroscopic rheometry to investigate triglyceride self-assembly

2017 ◽  
Vol 232 (7) ◽  
pp. 851-860
Author(s):  
Hamid A Elemsimit ◽  
Dana Grecov
Keyword(s):  
Rheological Behavior ◽  
Self Assembly ◽  
Graphite Substrate ◽  
Gap Size ◽  
Scanning Calorimetry ◽  
Self Assembled Monolayer ◽  
Surface Activities ◽  
Influence Of Substrate ◽  
Temperature Shear ◽  
Thermal Analysis Techniques

The rheological behavior of a canola oil-based bio-lubricant was correlated with its surface activities using a rotary rheometer. The experiments on the gap size, substrate, and surface conditions led to a consistent and conceivable assumption that the self-assembled monolayer was extended to a degree that was sufficient to make a significant change in the bulk properties. In parallel, the thermal behavior was also connected to the surface activities. Differential scanning calorimetry was used to measure what is thought to be the monolayer melting point without using a graphite substrate. Crystallization points were measured at relatively high temperatures. Tribological tests were conducted and explained based on the rheological and thermal findings. A scenario describing both the boundary and bulk regimes was hypothesized. Rheometry and thermal analysis techniques are promising because of the variety of variables that could be controlled, such as temperature, shear, time, gap and substrate. To the best of our knowledge, this is the first study using macroscopic rheology to study the surfactant activities of vegetable oil. The influence of substrate and gap size on rheological behavior could change the current standards for using rotary rheometers.

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