Scaling properties of the shear modulus of polyelectrolyte complex coacervates: a time-pH superposition principle

2015 ◽  
Vol 17 (35) ◽  
pp. 22552-22556 ◽  
Author(s):  
M. Tekaat ◽  
D. Bütergerds ◽  
M. Schönhoff ◽  
A. Fery ◽  
C. Cramer
Keyword(s):  
Shear Modulus ◽  
Polyelectrolyte Complex ◽  
Superposition Principle ◽  
Scaling Properties ◽  
Shear Moduli ◽  
Complex Shear

A novel time-pH superposition principle describes the complex shear moduli in polyelectrolyte complex coacervates.

scholarly journals A sensitive dynamic viscometer for measuring the complex shear modulus in a steady shear flow using the method of orthogonal superposition

1995 ◽  
Vol 34 (6) ◽  
pp. 606-621 ◽  
Author(s):  
Jos Zeegers ◽  
Dirk van den Ende ◽  
Cor Blom ◽  
Egbert G. Altena ◽  
Gerrit J. Beukema ◽  
...  
Keyword(s):  
Shear Flow ◽  
Shear Modulus ◽  
Steady Shear ◽  
Complex Shear Modulus ◽  
Complex Shear ◽  
Steady Shear Flow ◽  
Dynamic Viscometer

scholarly journals Estimation of quadriceps femoris muscle dysfunction in the early period after surgery of the knee joint using shear-wave elastography

2018 ◽  
Vol 4 (1) ◽  
pp. e000381 ◽  
Author(s):  
Makoto Kawai ◽  
Keigo Taniguchi ◽  
Tomoyuki Suzuki ◽  
Masaki Katayose
Keyword(s):  
Shear Modulus ◽  
Knee Joint ◽  
Patient Group ◽  
Quadriceps Femoris ◽  
Control Group ◽  
Muscle Dysfunction ◽  
Shear Moduli ◽  
Quadriceps Femoris Muscle ◽  
Contraction Ratio ◽  
Femoris Muscle

ObjectivesOrthopaedic surgery of the knee joint results in functional deterioration of the quadriceps femoris muscle. However, little is known about quadriceps femoris muscle dysfunction in the early postsurgical period. Therefore, we examined the stiffness of the quadriceps femoris muscle in the early postsurgical period.MethodsSeven patients and seven healthy controls performed quadriceps contraction exercises. In resting and contraction conditions, the shear modulus, muscle thickness and pennation angle were measured for the vastus medialis (VM), vastus lateralis (VL) and the rectus femoris (RF) using ultrasound elastography.ResultsThe shear moduli of the VM, VL and RF in the control group did not significantly interact, while the shear moduli in the patient group did show a significant interaction. In the resting condition, there was no difference between the unaffected and affected sides in the patient group, but the shear moduli of the VM and VL in the contraction condition was significantly lower on the affected side than the unaffected side.The contraction ratios between muscles by limbs did not significantly interact. However, there were main effects due to muscle and limb factors. The VM and VL had a significantly higher contraction ratio than the RF, and the control and unaffected limbs had a higher contraction ratio than the affected limb.ConclusionThe results demonstrated a decrease in muscle stiffness during contraction in patients with quadriceps femoris dysfunction. Measurement of the shear modulus has potential as a new evaluation index and with high sensitivity to decreases in muscle contraction.

Comparative study of destructive, nondestructive, and numerical procedures for the determination of moisture dependent shear moduli in Scots pine wood

2021 ◽  
Vol 63 (11) ◽  
pp. 1063-1069
Author(s):  
Murat Aydın ◽  
Hasan Hüseyin Ciritcioğlu
Keyword(s):  
Finite Element ◽  
Relative Humidity ◽  
Shear Modulus ◽  
Scots Pine ◽  
Constant Temperature ◽  
Transverse Wave ◽  
Element Analysis ◽  
Shear Moduli ◽  
Principal Axes ◽  
Static Shear

Abstract In this study, moisture dependent shear moduli in Scots pine (Pinus sylvestris L.) wood were determined by a 45° off-axis (longitudinal, radial, and tangential) compression test and ultrasonic transverse wave propagation. Finite element modeling was performed to ascertain how the results agree with the numerical method. Ultrasonic transverse wave velocities on the LR, LT, and RT planes were decreased from 1347, 1323, and 589 m × s-1 to 1286, 1269, and 561 m × s-1 when relative humidity increased from 45 % to 85 % at a constant temperature of 20 ± 1 °C, respectively. The dynamic and static shear modulus on the LR, LT, and RT planes were decreased from 988, 953, and 189, and 966, 914, and 182 MPa to 927, 903, and 176, and 845, 784, and 154 MPa when relative humidity increased from 45 % to 85 % at a constant temperature of 20 ± 1 °C, respectively. Therefore, both velocity and modulus values at all principal axes and planes were decreased with an increase in moisture. Maximum (15.2 %) and minimum (2.3 %) differences between dynamic and the static shear modulus were observed for GLT at 85 % and GLR at 45 % relative humidity, respectively. Coefficients of determinations between the dynamic and static shear moduli were ranged from 0.68 (GLR at 65 % RH) to 0.97 (GLR at 85 % RH). Finite element analysis, only for 65 % RH values, was performed using Solid 45 element, and, according to results, load-deformation curves created by linear orthotropic material properties, are well-matched with the static curves.

scholarly journals Predictions of the shear modulus of cheese, a soft matter approach

2019 ◽  
Vol 29 (1) ◽  
pp. 58-68 ◽  
Author(s):  
Graeme Gillies
Keyword(s):  
Shear Modulus ◽  
Soft Matter ◽  
Volume Fraction ◽  
Quantitative Model ◽  
Nano Particles ◽  
Core Shell ◽  
Two Dimensional ◽  
Shear Moduli ◽  
Numerical Predictions ◽  
The Many

Abstract The rheological and structural properties of cheese govern many physical processes associated with cheese such as slumping, slicing and melting. To date there is no quantitative model that predicts shear modulus, viscosity or any other rheological property across the entire range of cheeses; only empirical fits that interpolate existing data. A lack of a comprehensive model is in part due to the many variables that can affect rheology such as salt, pH, calcium levels, protein to moisture ratio, age and temperature. By modelling the casein matrix as a series core-shell nano particles assembled from calcium and protein these variables can be reduced onto a simpler two-dimensional format consisting of attraction and equivalent hard sphere volume fraction. Approximating the interaction between core-shell nano particles with a Mie potential enables numerical predictions of shear moduli. More qualitatively, this two-dimensional picture can be applied quite broadly and captures the viscoelastic behaviour of soft and hard cheeses as well as their melting phenomena.

Sign in / Sign up

Export Citation Format

Share Document