Double Crystal Melting Peak Generation for Expanded Polypropylene Bead Foam Manufacturing

2013 ◽  
Vol 52 (6) ◽  
pp. 2297-2303 ◽  
Author(s):  
Mohammadreza Nofar ◽  
Yanting Guo ◽  
Chul B. Park
Keyword(s):  
Melting Peak ◽  
Double Crystal ◽  
Crystal Melting

Evolution of double crystal melting peak in polypropylene foam assisted by β-nucleating agent and supercritical CO2

2017 ◽  
Vol 135 (12) ◽  
pp. 46007 ◽  
Author(s):  
Kesong Yu ◽  
Hanchuan Jiang ◽  
Hongfu Zhou ◽  
Jianguo Mi ◽  
Yadong He ◽  
...  
Keyword(s):  
Supercritical Co2 ◽  
Nucleating Agent ◽  
Melting Peak ◽  
Double Crystal ◽  
Crystal Melting ◽  
Polypropylene Foam

Manufacturing of High-Performance Nano/Microcellular Expanded PLA Bead Foams

2015 ◽  
Author(s):  
Mohammadreza Nofar ◽  
Chul B. Park
Keyword(s):  
High Performance ◽  
Expansion Ratio ◽  
The Other ◽  
Melting Peak ◽  
High Melting ◽  
Double Crystal ◽  
Peak Structure ◽  
Cell Nucleation ◽  
Crystal Melting ◽  
Foaming Technology

In this study, expanded polylactide (EPLA) bead foams were produced with cellular morphology ranging from nanocellular to microcellular. This was achieved by using bead foaming technology while a double crystal melting peak structure was generated. The high melting peak crystals generated during the gas saturation played an important role on controlling the cell size and expansion ratio of the foamed beads. As the amount of high melting peak crystals increased, the cell sizes were reduced to around 350 nm while the expansion ratio was around 3-fold. In other words, the induced perfected crystals significantly promoted the heterogeneous cell nucleation while hindering the cell growth. On the other hand, with the reduced amount of these perfected crystals, the cell sizes were increased to around 15 μm and the expansion ratio of the foamed beads increased to 30-fold.

Development of polylactide bead foams with double crystal melting peaks

Polymer ◽  
2015 ◽  
Vol 69 ◽  
pp. 83-94 ◽  
Author(s):  
Mohammadreza Nofar ◽  
Aboutaleb Ameli ◽  
Chul B. Park
Keyword(s):  
Double Crystal ◽  
Crystal Melting

Defect morphology in thick relaxed layers of InGaAs on GaAs

1990 ◽  
Vol 48 (4) ◽  
pp. 668-669
Author(s):  
R H Dixon ◽  
P Kidd ◽  
P J Goodhew
Keyword(s):  
Electron Microscopy ◽  
Surface Morphology ◽  
Growth Conditions ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
Strained Layers ◽  
Good Surface ◽  
Transmission Electron ◽  
Device Structures ◽  
Surface Morphologies

Thick relaxed InGaAs layers grown epitaxially on GaAs are potentially useful substrates for growing high indium percentage strained layers. It is important that these relaxed layers are defect free and have a good surface morphology for the subsequent growth of device structures.3μm relaxed layers of InxGa1-xAs were grown on semi - insulating GaAs substrates by Molecular Beam Epitaxy (MBE), where the indium composition ranged from x=0.1 to 1.0. The interface, bulk and surface of the layers have been examined in planar view and cross-section by Transmission Electron Microscopy (TEM). The surface morphologies have been characterised by Scanning Electron Microscopy (SEM), and the bulk lattice perfection of the layers assessed using Double Crystal X-ray Diffraction (DCXRD).The surface morphology has been found to correlate with the growth conditions, with the type of defects grown-in to the layer (e.g. stacking faults, microtwins), and with the nature and density of dislocations in the interface.

A DOUBLE CRYSTAL MONOCHROMATOR FOR SOFT X-RAY BEAM LINE OF UVSOR

1986 ◽  
Vol 47 (C8) ◽  
pp. C8-135-C8-137
Author(s):  
T. MURATA ◽  
T. MATSUKAWA ◽  
M. MORI ◽  
M. OBASHI ◽  
S.-I. NAO-E ◽  
...  
Keyword(s):  
Beam Line ◽  
Double Crystal ◽  
X Ray ◽  
Double Crystal Monochromator

Double Crystal X‐Ray Dilatometer Using Continuous Radiation

1971 ◽  
Vol 42 (2) ◽  
pp. 196-199 ◽  
Author(s):  
Virgil E. Bottom ◽  
Renê Ayres Carvalho
Keyword(s):  
Double Crystal ◽  
X Ray ◽  
Continuous Radiation

Strain Shift Coefficients for Phonons in Si-Ge Heterostructures

1991 ◽  
Vol 239 ◽  
Author(s):  
J.-M. Baribeau ◽  
D. J. Lockwood
Keyword(s):  
Molecular Beam ◽  
Composition Dependence ◽  
Vibration Mode ◽  
Phonon Frequency ◽  
Longitudinal Optical ◽  
Stress Factor ◽  
Double Crystal ◽  
Raman Scattering Spectroscopy ◽  
X Ray ◽  
Shift Coefficient

ABSTRACTStrain shift coefficient measurements for longitudinal optical phonons in molecular beam epitaxy grown metastable pseudomorphic Si1−xGex layers on (100) Si (0 < x < 0.35) and Ge (0.80 < x < 1) are reported. Strain in partially relaxed annealed specimens was obtained by double-crystal x-ray diffractometry and the corresponding strain phonon shift was measured by Raman scattering spectroscopy. For epilayers grown on Si it was found that the epilayer Si-Si phonon frequency varies linearly with strain. The magnitude of the strain shift coefficient b however showed a small composition dependence varying from b ≈ -700 cm-1 at x = 0 to b ≈ -950 cm-1 at x = 0.35, corresponding to a stress factor τ = 0.40 + 0.57x: + 0.13x2 cm-1/kbar. For the Ge-Ge vibration mode in epilayers grown on Ge, b decreased from ∼-425 cm-1 at x = 1 to ∼-500 cm-1 at x = 0.8, corresponding to a stress factor τ ≈ 0.52 – 0.14x - 0.08x2 cm-1/kbar.

Assessment of Thin Heteroepitaxial Layers Using Skew Angle Asymmetrical X-Ray Double Crystal Diffraction

1988 ◽  
Vol 138 ◽  
Author(s):  
S. J. Miles ◽  
G. S. Green ◽  
B. K. Tanner ◽  
M. A. G. Halliwell ◽  
M. H. Lyons
Keyword(s):  
Skew Angle ◽  
Double Crystal ◽  
X Ray ◽  
Heteroepitaxial Layers

Selective Area Deposition of Passivants, Insulators, and Epitaxial Films of II-VI Compound Semiconductors

1989 ◽  
Vol 161 ◽  
Author(s):  
D.L. Dreifus ◽  
Y. Lansari ◽  
J.W. Han ◽  
S. Hwang ◽  
J.W. Cook ◽  
...  
Keyword(s):  
Ohmic Contacts ◽  
Epitaxial Films ◽  
Semiconductor Surface ◽  
Epitaxial Layers ◽  
Double Crystal ◽  
Surface Areas ◽  
Selective Area ◽  
Lift Off ◽  
P Type ◽  
Area Deposition

ABSTRACTII-VI semiconductor surface passivants, insulators, and epitaxial films have been deposited onto selective surface areas by employing a new masking and lift-off technique. The II-VI layers were grown by either conventional or photoassisted molecular beam epitaxy (MBE). CdTe has been selectively deposited onto HgCdTe epitaxial layers as a surface passivant. Selective-area deposition of ZnS has been used in metal-insulator-semiconductor (MIS) structures. Low resistance ohmic contacts to p-type CdTe:As have also been realized through the use of selectively-placed thin films of the semi-metal HgTe followed by a thermal evaporation of In. Epitaxial layers of HgTe, HgCdTe, and HgTe-CdTe superlattices have also been grown in selective areas on CdZnTe substrates, exhibiting specular morphologies and double-crystal x-ray diffraction rocking curves (DCXD) with full widths at half maximum (FWHMs) as narrow as 140 arcseconds.

Axisymmetric Finite-Element Analysis for Interface Migration-Controlled Shape Instabilities of Plate-Like Double-Crystal Grains

2012 ◽  
Vol 460 ◽  
pp. 230-235
Author(s):  
Pei Zhen Huang ◽  
Zhou Zhou Zhang ◽  
Jian Wei Guo ◽  
Jun Sun
Keyword(s):  
Finite Element ◽  
Grain Boundary ◽  
Chemical Potential ◽  
Boundary Energy ◽  
Element Analysis ◽  
Interface Motion ◽  
Double Crystal ◽  
Energy Principle ◽  
Chemical Potential Difference ◽  
Interface Migration

An axisymmetric finite-element method is developed to predict the evolution behavior of microstructures by interface migration. The formulation of the method is conducted on the basis of the energy principle during the interface motion. The computations extend earlier models by accounting in detail for the effects of grain-boundary energy, surface energy and chemical potential difference. The eventual shape of the plate-like double-crystal grain depends on both the initial β and the thermal grooving angle Ψ. For a given β, a critical Ψcexists. When Ψ>Ψc, the eventual shape is one made of two sphere segments with a thermal groove. When Ψ≤Ψc, grain splitting along the grain boundary occurs, and the splitting segments evolve into two spheres, respectively. Both the spheroidization time and the splitting time increase with Ψ and β increasing. The volume shrinkage rate decreases with increasing Ψ.

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