scholarly journals Dissolution of Indomethacin Crystals into a Polymer Melt: Role of Diffusion and Fragmentation

2019 ◽  
Vol 19 (6) ◽  
pp. 3315-3328 ◽  
Author(s):  
Dana E. Moseson ◽  
Andrew S. Parker ◽  
Christopher J. Gilpin ◽  
Andrew A. Stewart ◽  
Stephen P. Beaudoin ◽  
...  
Keyword(s):  
Polymer Melt

The Role of Temperature in the Entanglement Kinetics of a Polymer Melt

1995 ◽  
Vol 62 (3) ◽  
pp. 794-801 ◽  
Author(s):  
R. S. Jeyaseelan ◽  
A. J. Giacomin
Keyword(s):  
Network Theory ◽  
Rate Constants ◽  
Polymer Melt ◽  
Large Amplitude Oscillatory Shear ◽  
Kinetic Rate ◽  
Kinetic Rate Constants ◽  
Different Temperatures ◽  
Transient Network ◽  
Kinetics Of

Large-amplitude oscillatory shear (LAOS) experiments were conducted at different temperatures on a molten low-density polyethylene standard, designated IUPAC LDPE X. Jeyaseelan et al. (1993) have successfully employed a simplification of transient network theory to describe the LAOS behavior of this polymer melt, at 150°C. The transient network is described by two kinetic rate constants, one for the formation of entanglements due to Brownian motion (k1), and another for the destruction of entanglements (k2) due to the imposed deformation. Upon comparison of the predictions of this transient network theory with the measured LAOS behavior of this polymer, we find that the kinetic rate constants k1 and k2 are invariant in the range of temperatures examined (150 to 190°C). The temperature dependence of departures from linear viscoelasticity is fully accounted for in the equilibrium entanglement kinetics.

The role of flow-induced crystallisation in melt spinning

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Andrzej Ziabicki ◽  
Leszek Jarecki ◽  
Andrea Sorrentino
Keyword(s):  
Experimental Data ◽  
Rheological Properties ◽  
Melt Spinning ◽  
Rheological Behaviour ◽  
Polymer Melt ◽  
Temperature Profiles ◽  
Model Calculations ◽  
On Line

Abstract Flow-induced crystallisation in the course of melt spinning changes properties of as-spun fibres and modifies dynamics of the process. Velocity, stress and temperature profiles depend on the speed of on-line crystallisation. Very important but little studied is coupling between crystallinity and rheological properties of the polymer melt. Effects of crystallisation on the dynamics of melt spinning and on the rheological behaviour have been discussed and compared with model calculations and available experimental data.

The role of polymer melt viscoelastic network behavior in lithium ion transport for PEO melt/LiClO4 SPEs: the “wet gel” model

2000 ◽  
Vol 89 (2) ◽  
pp. 168-175 ◽  
Author(s):  
R Walter ◽  
R Walkenhorst ◽  
M Smith ◽  
J.C Selser ◽  
G Piet ◽  
...  
Keyword(s):  
Ion Transport ◽  
Lithium Ion ◽  
Polymer Melt ◽  
Network Behavior

Numerical Evaluation of Single Fiber Motion for Short-Fiber-Reinforced Composite Materials Processing

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
Dongdong Zhang ◽  
Douglas E. Smith ◽  
David A. Jack ◽  
Stephen Montgomery-Smith
Keyword(s):  
Aspect Ratio ◽  
Original Work ◽  
Polymer Melt ◽  
Short Fiber ◽  
Single Fiber ◽  
Runge Kutta Method ◽  
Reinforced Composite ◽  
Fiber Motion ◽  
Angular Velocities

This paper presents a computational approach for simulating the motion of a single fiber suspended within a viscous fluid. We develop a finite element method (FEM) for modeling the dynamics of a single rigid fiber suspended in a moving fluid. Our approach seeks solutions using the Newton–Raphson method for the fiber’s linear and angular velocities such that the net hydrodynamic forces and torques acting on the fiber are zero. Fiber motion is then computed with a Runge-Kutta method to update the fiber position and orientation as a function of time. Low-Reynolds-number viscous flows are considered since these best represent the flow conditions for a polymer melt within a mold cavity. This approach is first used to verify Jeffery’s orbit (1922) and addresses such issues as the role of a fiber’s geometry on the dynamics of a single fiber, which were not addressed in Jeffery’s original work. The method is quite general and allows for fiber shapes that include, but are not limited to, ellipsoidal fibers (such as that studied in Jeffery’s original work), cylindrical fibers, and bead-chain fibers. The relationships between equivalent aspect ratio and geometric aspect ratio of cylindrical and other axisymmetric fibers are derived in this paper.

Temperature-Driven Grafted Nanoparticle Penetration into Polymer Melt: Role of Enthalpic and Entropic Interactions

2020 ◽  
Vol 53 (19) ◽  
pp. 8674-8682
Author(s):  
Nimmi Das A ◽  
Aparna Swain ◽  
Nafisa Begam ◽  
Arpan Bhattacharyya ◽  
J. K. Basu
Keyword(s):  
Polymer Melt ◽  
Grafted Nanoparticle

The Role of Internal Rotational Barriers in Polymer Melt Chain Dynamics

2002 ◽  
Vol 35 (10) ◽  
pp. 4198-4203 ◽  
Author(s):  
S. Krushev ◽  
W. Paul ◽  
G. D. Smith
Keyword(s):  
Polymer Melt ◽  
Chain Dynamics ◽  
Rotational Barriers ◽  
Internal Rotational Barriers

Role of dactinomycin in the improved survival of children with Wilms' tumor

JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 1005-1009 ◽  
Author(s):  
D. J. Fernbach
Keyword(s):  
Wilms Tumor

Role of the allergist in diagnosis and management of patients with uveitis

JAMA ◽  
1966 ◽  
Vol 195 (3) ◽  
pp. 167-172 ◽  
Author(s):  
T. E. Van Metre
Keyword(s):  
Diagnosis And Management

The power of norms to sway fused group members

2018 ◽  
Vol 41 ◽  
Author(s):  
Winnifred R. Louis ◽  
Craig McGarty ◽  
Emma F. Thomas ◽  
Catherine E. Amiot ◽  
Fathali M. Moghaddam
Keyword(s):  
Evolutionary Anthropology ◽  
Normative Systems ◽  
Violent Extremism ◽  
Identity Fusion ◽  
Group Members

AbstractWhitehouse adapts insights from evolutionary anthropology to interpret extreme self-sacrifice through the concept of identity fusion. The model neglects the role of normative systems in shaping behaviors, especially in relation to violent extremism. In peaceful groups, increasing fusion will actually decrease extremism. Groups collectively appraise threats and opportunities, actively debate action options, and rarely choose violence toward self or others.

Elaborating the role of reflection and individual differences in the study of folk-economic beliefs

2018 ◽  
Vol 41 ◽  
Author(s):  
Kevin Arceneaux
Keyword(s):  
Decision Making ◽  
Individual Differences ◽  
Cognitive Processes ◽  
Evolutionary History ◽  
Behavioral Responses ◽  
History Of ◽  
Economic Beliefs

AbstractIntuitions guide decision-making, and looking to the evolutionary history of humans illuminates why some behavioral responses are more intuitive than others. Yet a place remains for cognitive processes to second-guess intuitive responses – that is, to be reflective – and individual differences abound in automatic, intuitive processing as well.

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