A modified power law model for the steady shear viscosity of polystyrene melts

1990 ◽  
Vol 30 (10) ◽  
pp. 587-595 ◽  
Author(s):  
Gregory A. Campbell ◽  
Mary Elizabeth Adams
Keyword(s):  
Power Law ◽  
Shear Viscosity ◽  
Steady Shear ◽  
Power Law Model ◽  
Steady Shear Viscosity ◽  
Modified Power Law

Thermal Property, Morphology, Mechanical and Rheological Properties of a Modified Bio-Polymers Prepared by Blending Poly(3-Hydrobutyrate-Co-4-Hydrobutyrate) with Chain Extenders

2010 ◽  
Vol 152-153 ◽  
pp. 924-930
Author(s):  
Mei Li ◽  
Zhi Qiang Li ◽  
Jun Xu ◽  
Dun Sheng Wei ◽  
Hong Wei Zhu ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Shear Viscosity ◽  
Loss Modulus ◽  
Freeze Fracture ◽  
Fracture Morphology ◽  
Steady Shear ◽  
Thermal Transitions ◽  
Remarkable Effect ◽  
Steady Shear Viscosity ◽  
Chain Extenders

Modified Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] was prepared by melt reactive blending P(3HB-co-4HB) with chain extenders (ADR-4367). Thermal transitions, spherulitic and freeze-fracture morphology, mechanical and rheological properties of the chain extended bio-materials were investigated. The results show that glass transition temperatures and crystallization temperatures increase, crystallinity and diameters of spherulites decrease, there are amorphous parts dispersed among the crystalline phase, and the bio-materials transfer from brittleness to toughness and ductility. Steady shear viscosity of the modified P(3HB-co-4HB) increases by about one order of magnitude, melts of the modified P(3HB-co-4HB) behave more viscoelasticity by storage modulus and loss modulus correlated with oscillatory shear frequency. Addition of ADR-4367 with contents of 4~6 wt% in the blends is enough to branching and coupling the co-polymer chains and brings remarkable effect on improving mechanical properties, steady shear viscosity and viscoelasticity.

STEADY SHEAR VISCOSITY OF ULTRAFILTERED WHOLE AND SKIM MILK RETENTATES BEFORE AND DURING FERMENTATION

1999 ◽  
Vol 30 (5) ◽  
pp. 549-561
Author(s):  
D. M. MUN ◽  
T.-T. HSIEH ◽  
C. TIU ◽  
B. J. SUTHERLAND
Keyword(s):  
Shear Viscosity ◽  
Skim Milk ◽  
Steady Shear ◽  
Steady Shear Viscosity

The role of protein content on the steady and oscillatory shear rheology of model synovial fluids

Soft Matter ◽  
2014 ◽  
Vol 10 (32) ◽  
pp. 5965-5973 ◽  
Author(s):  
Z. Zhang ◽  
S. Barman ◽  
G. F. Christopher
Keyword(s):  
Hyaluronic Acid ◽  
Synovial Fluid ◽  
Acid Solution ◽  
Protein Content ◽  
Shear Viscosity ◽  
Steady Shear ◽  
Interfacial Rheology ◽  
Steady Shear Viscosity ◽  
Synovial Fluids

Model synovial fluid steady shear viscosity to hyaluronic acid solution are identical when interfacial rheology effects are removed.

Height Extrapolation of Wind Data

1985 ◽  
Vol 107 (1) ◽  
pp. 10-14 ◽  
Author(s):  
A. S. Mikhail
Keyword(s):  
Wind Speed ◽  
Power Law ◽  
Wind Data ◽  
Power Law Model ◽  
Short Term ◽  
Shape Factors ◽  
Wind Speeds ◽  
Average Wind ◽  
Modified Power Law

Various models that are used for height extrapolation of short and long-term averaged wind speeds are discussed. Hourly averaged data from three tall meteorological towers (the NOAA Erie Tower in Colorado, the Battelle Goodnoe Hills Tower in Washington, and the WKY-TV Tower in Oklahoma), together with data from 17 candidate sites (selected for possible installation of large WECS), were used to analyze the variability of short-term average wind shear with atmospheric and surface parameters and the variability of the long-term Weibull distribution parameter with height. The exponents of a power-law model, fit to the wind speed profiles at the three meteorological towers, showed the same variability with anemometer level wind speed, stability, and surface roughness as the similarity law model. Of the four models representing short-term wind data extrapolation with height (1/7 power law, logarithmic law, power law, and modified power law), the modified power law gives the minimum rms for all candidate sites for short-term average wind speeds and the mean cube of the speed. The modified power-law model was also able to predict the upper-level scale factor for the WKY-TV and Goodnoe Hills Tower data with greater accuracy. All models were not successful in extrapolation of the Weibull shape factors.

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