Characterization of Quantum Heterostructures. A Simulation Method Combining the Evaluation of Lattice and Electrons Configuration and TEM Imaging.

1995 ◽  
Vol 389 ◽  
Author(s):  
G. Mattei ◽  
A. M. Mazzone
Keyword(s):  
Structural Properties ◽  
Diffraction Method ◽  
Simulation Method ◽  
Hrem Image ◽  
Dynamical Diffraction ◽  
Quantum Heterostructures

ABSTRACTThis work analyzes the characterization of the structural properties of quantum heterostructures by HREM. A simulation of atomistic type is used to construct a Fe/Ag bilayer few nm thick and the HREM image of this structure is calculated by using a standard dynamical diffraction method. The comparison of the two calculations indicates that the interfacial disorder spans few layers and can be resolved against the background of two well-registered lattices.

High-resolution electron microscopy of nanostructured materials

1995 ◽  
Vol 53 ◽  
pp. 172-173
Author(s):  
M. José-Yacamán
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Grain Boundaries ◽  
Nanostructured Materials ◽  
High Resolution Electron Microscopy ◽  
Hrem Image ◽  
Small Particles ◽  
Resolution Electron ◽  
Nanophase Materials

Electron microscopy is a fundamental tool in materials characterization. In the case of nanostructured materials we are looking for features with a size in the nanometer range. Therefore often the conventional TEM techniques are not enough for characterization of nanophases. High Resolution Electron Microscopy (HREM), is a key technique in order to characterize those materials with a resolution of ~ 1.7A. High resolution studies of metallic nanostructured materials has been also reported in the literature. It is concluded that boundaries in nanophase materials are similar in structure to the regular grain boundaries. That work therefore did not confirm the early hipothesis on the field that grain boundaries in nanostructured materials have a special behavior. We will show in this paper that by a combination of HREM image processing, and image calculations, it is possible to prove that small particles and coalesced grains have a significant surface roughness, as well as large internal strain.

Characterization of Structural Properties in High Reynolds Hydraulic Jump Based on CFD and Physical Modeling Approaches

2020 ◽  
Vol 146 (12) ◽  
pp. 04020079 ◽  
Author(s):  
Juan Francisco Macián-Pérez ◽  
Arnau Bayón ◽  
Rafael García-Bartual ◽  
P. Amparo López-Jiménez ◽  
Francisco José Vallés-Morán
Keyword(s):  
Structural Properties ◽  
Physical Modeling ◽  
Hydraulic Jump ◽  
Modeling Approaches ◽  
High Reynolds

Operating Temperature Analysis of LED with Cylindrical Cu Slug

2014 ◽  
Vol 487 ◽  
pp. 145-148 ◽  
Author(s):  
Rajendaran Vairavan ◽  
Zaliman Sauli ◽  
Vithyacharan Retnasamy
Keyword(s):  
Natural Convection ◽  
Operating Temperature ◽  
Simulation Method ◽  
Input Power ◽  
Junction Temperature ◽  
Temperature Analysis ◽  
Light Emitting ◽  
New Era ◽  
Lighting Systems

High power light emitting diodes is the new era of lighting due to momentous supremacy in terms of lighting efficacy over traditional lighting systems. The reliability of LED is dependent on its junction temperature. This study confers on the thermal and stress characterization of LED chip with copper cylindrical heat slug through simulation method. The simulation characterization was carried out with Ansys version 11 at ambient temperature of 25°C under natural convection condition. The LED package was powered with input powers of 0.1 W, 0.5 W and 1W .Results indicated that input power influences the junction temperature and stress of LED chip.

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