Three-dimensional numerical and experimental investigations on polymer rheology in meso-scale injection molding

2010 ◽  
Vol 37 (2) ◽  
pp. 131-139 ◽  
Author(s):  
C.Y. Khor ◽  
Z.M. Ariff ◽  
F. Che Ani ◽  
M. Abdul Mujeebu ◽  
M.K. Abdullah ◽  
...  
Keyword(s):  
Injection Molding ◽  
Three Dimensional ◽  
Experimental Investigations ◽  
Polymer Rheology ◽  
Meso Scale

scholarly journals Structural Characterization of Receptor–Receptor Interactions in the Allosteric Modulation of G Protein-Coupled Receptor (GPCR) Dimers

2021 ◽  
Vol 22 (6) ◽  
pp. 3241
Author(s):  
Raudah Lazim ◽  
Donghyuk Suh ◽  
Jai Woo Lee ◽  
Thi Ngoc Lan Vu ◽  
Sanghee Yoon ◽  
...  
Keyword(s):  
G Protein ◽  
Protein Interactions ◽  
Metabotropic Glutamate Receptor ◽  
Three Dimensional ◽  
Allosteric Modulation ◽  
Experimental Investigations ◽  
G Protein Coupled Receptor ◽  
Metabotropic Glutamate ◽  
Gpcr Activation ◽  
G Protein Coupled

G protein-coupled receptor (GPCR) oligomerization, while contentious, continues to attract the attention of researchers. Numerous experimental investigations have validated the presence of GPCR dimers, and the relevance of dimerization in the effectuation of physiological functions intensifies the attractiveness of this concept as a potential therapeutic target. GPCRs, as a single entity, have been the main source of scrutiny for drug design objectives for multiple diseases such as cancer, inflammation, cardiac, and respiratory diseases. The existence of dimers broadens the research scope of GPCR functions, revealing new signaling pathways that can be targeted for disease pathogenesis that have not previously been reported when GPCRs were only viewed in their monomeric form. This review will highlight several aspects of GPCR dimerization, which include a summary of the structural elucidation of the allosteric modulation of class C GPCR activation offered through recent solutions to the three-dimensional, full-length structures of metabotropic glutamate receptor and γ-aminobutyric acid B receptor as well as the role of dimerization in the modification of GPCR function and allostery. With the growing influence of computational methods in the study of GPCRs, we will also be reviewing recent computational tools that have been utilized to map protein–protein interactions (PPI).

Assessment of Unsteady Flows in Turbines

1992 ◽  
Vol 114 (1) ◽  
pp. 79-90 ◽  
Author(s):  
O. P. Sharma ◽  
G. F. Pickett ◽  
R. H. Ni
Keyword(s):  
Unsteady Flow ◽  
Three Dimensional ◽  
Flow Simulation ◽  
Experimental Investigations ◽  
Flow Parameters ◽  
Research Activities ◽  
Flow Features ◽  
Computational Fluid Dynamics Cfd ◽  
Turbine Design ◽  
The Impact

The impacts of unsteady flow research activities on flow simulation methods used in the turbine design process are assessed. Results from experimental investigations that identify the impact of periodic unsteadiness on the time-averaged flows in turbines and results from numerical simulations obtained by using three-dimensional unsteady Computational Fluid Dynamics (CFD) codes indicate that some of the unsteady flow features can be fairly accurately predicted. Flow parameters that can be modeled with existing steady CFD codes are distinguished from those that require unsteady codes.

Influence of a Honeycomb Facing on the Flow Through a Stepped Labyrinth Seal

2000 ◽  
Vol 124 (1) ◽  
pp. 140-146 ◽  
Author(s):  
V. Schramm ◽  
K. Willenborg ◽  
S. Kim ◽  
S. Wittig
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Theoretical Work ◽  
Labyrinth Seal ◽  
Honeycomb Structure ◽  
Experimental Investigations ◽  
Labyrinth Seals ◽  
Numerical Predictions ◽  
Flow Through ◽  
Aero Engines

This paper reports numerical predictions and measurements of the flow field in a stepped labyrinth seal. The theoretical work and the experimental investigations were successfully combined to gain a comprehensive understanding of the flow patterns existing in such elements. In order to identify the influence of the honeycomb structure, a smooth stator as well as a seal configuration with a honeycomb facing mounted on the stator wall were investigated. The seal geometry is representative of typical three-step labyrinth seals of modern aero engines. The flow field was predicted using a commercial finite volume code with the standard k-ε turbulence model. The computational grid includes the basic seal geometry as well as the three-dimensional honeycomb structures.

Key Technologies Research on Color Contour Map of 3D Injection Molding Simulation Results

2012 ◽  
Vol 217-219 ◽  
pp. 1998-2001
Author(s):  
Tie Geng ◽  
Qing Hai Ren ◽  
Wei Qing Tu ◽  
Dan Dan Liu
Keyword(s):  
Injection Molding ◽  
Color Image ◽  
Three Dimensional ◽  
Physical Field ◽  
Contour Map ◽  
Image Rendering ◽  
Color Range ◽  
Key Technologies ◽  
Injection Molding Simulation ◽  
Simulation Results

According to the color contour map of the 3D injection molding simulation results, the commonly used color contour map drawing algorithm was researched, and a three-dimensional color image rendering algorithm which based on the "physical field values and color range mapping" was given too. And the key technologies of the algorithm which was used to draw 3D color contour map were introduced in detail. In the end, an example was given.

Three-Dimensional Simulation of Co-Injection Molding

2001 ◽  
Author(s):  
Florin Ilinca ◽  
Jean-François Hétu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Injection Molding ◽  
Three Dimensional ◽  
Mold Temperature ◽  
Dimensional Finite Element ◽  
Dimensional Simulation ◽  
Energy Equations ◽  
Three Dimensional Finite Element ◽  
Core Materials

Abstract This paper presents simulations of co-injection molding problems computed by a three-dimensional finite element method. The polymer melts behave as generalized Newtonian fluids and non-isothermal effects are taken into account. In addition to the momentum, mass and energy equations, we solve two transport equations tracking the polymer/air and skin/core polymers interfaces. Solutions are shown for a center gated rectangular plate. The effect of varying the melt/mold temperature and the ratio between the skin and core materials is investigated. The solution obtained for the same skin and core materials is compared with those in which viscosities of core and skin materials are different. Finally, the solution for the co-injection of a C-shaped plate is presented.

scholarly journals Experimental Investigations of Interactions between Sand Wave Movements, Flow Structure, and Individual Aquatic Plants in Natural Rivers: A Case Study of Potamogeton Pectinatus L.

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1166 ◽  
Author(s):  
Łukasz Przyborowski ◽  
Anna Łoboda ◽  
Robert Bialik
Keyword(s):  
Flow Velocity ◽  
Three Dimensional ◽  
Potamogeton Pectinatus ◽  
Sand Wave ◽  
Experimental Investigations ◽  
Cross Sectional ◽  
Bending Tests ◽  
Long Duration ◽  
Elevation Changes

Long-duration measurements were performed in two sandy bed rivers, and three-dimensional (3D) flow velocity and bottom elevation changes were measured in a vegetated area and in a clear region of a river. Detailed flow velocity profiles downstream and upstream of a single specimen of Potamogeton pectinatus L. were obtained and the bed morphology was assessed. Potamogeton plants gathered from each river were subjected to tensile and bending tests. The results show that the existence of the plants was influenced by both bottom and flow conditions, as the plants were located where water velocity was lower by 12% to 16% in comparison to clear region. The characteristics of the flow and sand forms depended on the cross-sectional arrangement of the river, e.g., dunes were approximately four times higher in the middle of the river than in vegetated regions near the bank. Furthermore, the studied hydrophytes were too sparse to affect water flow and had no discernible impact on the sand forms’ movements. The turbulent kinetic energy downstream of a single plant was reduced by approximately 25%. Additionally, the plants’ biomechanical characteristics and morphology were found to have adjusted to match the river conditions.

Polypropylene Based Piezo Ceramic Compounds for Micro Injection Molded Sensors

2017 ◽  
Vol 742 ◽  
pp. 807-814 ◽  
Author(s):  
Christoph Doerffel ◽  
Ricardo Decker ◽  
Michael Heinrich ◽  
Jürgen Tröltzsch ◽  
Mirko Spieler ◽  
...  
Keyword(s):  
Injection Molding ◽  
Ceramic Powder ◽  
Three Dimensional ◽  
Conductive Filler ◽  
High Sensitivity ◽  
Injection Molding Process ◽  
Molding Process ◽  
Ceramic Particles ◽  
Wide Range ◽  
Ceramic Compounds

Polymer matrix compounds based on piezo ceramic and electrically conducting particles within a thermoplastic matrix show distinctive piezoelectric and dielectric effects which can used for sensor applications. The electrical and mechanical properties can be adjusted in a wide range by varying the ratio of active filling particles and the matrix materials. The sensor effect of the compound is generated by the ceramic particles. A large ratio of piezo ceramic powder facilitates a high sensitivity. The electrical permittivity of the otherwise insulating matrix polymer can be adjusted by the amount of conductive filler. An aligned permittivity leads to a stronger electrical field in the ceramic particles. In contrast, too many conductive particles create a conductive network in the compound which short-circuits the sensors. The piezo ceramic compounds can be processed via micro injection molding for application as ceramic sensors. This offers a wide range of new sensor design variants, notably three-dimensional and highly complex geometries. However, there are two main demands for a highly sensitive sensor, which are conflicting. On the one hand the filler content of piezo ceramic particles in combination with electrical conductive carbon nanotubes must be very high, on the other hand the wall thickness should be as thin as possible. For filling cavities with a high aspect-ratio in an injection molding process, low viscosity polymer melts are necessary. These process characteristics conflict with the increasing viscosity by filling the melt with the particles. The sensor measuring area has to be designed as thin walled as possible. In order to overcome this obstacle a dynamically tempered mold design is applied to avoid solidification of the melt, before the mold is completely filled. The mold can be tempered by Peltier elements. The fully electric tempering is cleaner, more precise and more reliable than conventional water or oil tempering.

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