Effect of uniaxial stress on electroluminescence, valence band modification, optical gain, and polarization modes in tensile strainedp-AlGaAs/GaAsP/n-AlGaAs laser diode structures: Numerical calculations and experimental results

2012 ◽  
Vol 112 (9) ◽  
pp. 093113 ◽  
Author(s):  
E. V. Bogdanov ◽  
N. Ya. Minina ◽  
J. W. Tomm ◽  
H. Kissel
1997 ◽  
Vol 482 ◽  
Author(s):  
A. A. Yamaguchi ◽  
Y. Mochizuki ◽  
C. Sasaoka ◽  
A. Kimura ◽  
M. Nido ◽  
...  

AbstractValence band modification by uniaxial stress in GaN is investigated by reflectance spectroscopy. It is observed that the energy separation between the A and B valence bands increases with the applied uniaxial stress in the c-plane. Changes of the wavefunctions by the stress are also investigated by the polarization characteristics of the reflectance spectra. The experimental results are analyzed on the basis of k•p theory, and deformation potential D5 is experimentally determined as -3.3 eV. It is indicated that the uniaxial strain effect could be utilized for improving GaN-based laser performance.


2011 ◽  
Vol 4 (5) ◽  
pp. 052103 ◽  
Author(s):  
Yoon Seok Kim ◽  
Akio Kaneta ◽  
Mitsuru Funato ◽  
Yoichi Kawakami ◽  
Takashi Kyono ◽  
...  
Keyword(s):  

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 246 ◽  
Author(s):  
Jorge Manuel Mercado-Colmenero ◽  
Cristina Martin-Doñate ◽  
Vincenzo Moramarco ◽  
Michele Angelo Attolico ◽  
Gilda Renna ◽  
...  

This manuscript presents an experimental and numerical analysis of the mechanical structural behavior of Nylstrong GF-PA6, a plastic material manufactured using FDM (fused deposition modeling) technology for a compression uniaxial stress field. Firstly, an experimental test using several test specimens fabricated in the Z and X-axis allows characterizing the elastic behavior of the reinforced GF-PA6 according to the ISO 604 standard for uniaxial compression stress environments in both Z and X manufacturing orientations. In a second stage, an experimental test analyzes the structural behavior of an industrial part manufactured under the same conditions as the test specimens. The experimental results for the test specimens manufactured in the Z and X-axis present differences in the stress-strain curve. Z-axis printed elements present a purely linear elastic behavior and lower structural integrity, while X-axis printed elements present a nonlinear elastic behavior typical of plastic and foam materials. In order to validate the experimental results, numerical analysis for an industrial part is carried out, defining the material GF-PA6 as elastic and isotropic with constant Young’s compression modulus according to ISO standard 604. Simulations and experimental tests show good accuracy, obtaining errors of 0.91% on the Z axis and 0.56% on the X-axis between virtual and physical models.


Author(s):  
In-Hwan Yang ◽  
Mohamed S. El-Genk

Numerical calculations are performed to investigate the effect of viscous dissipation on the temperature rise and friction numbers for laminar water flows in micro-tubes. The calculated values are compared with those determined from reported experimental data for glass and diffused silica micro-tubes (D = 16 – 101 μm and L/D = 625 – 1479). The results confirm a definite slip at the wall with slip lengths of ∼ 0.7 μm and 1.0 μm, which decrease the friction number and the temperature rise in the micro-tubes, but their effect gradually diminishes as either D or L/D increases. The friction number decreases exponentially as D decreases and, to a lesser extent, as L/D increases. The effect of L/D on the friction number is insignificant for micro-tube diameters ≤ 20 μm. For D > 400 μm, the friction number approaches that of Hagen-Posieuille of 64 for macro-tubes when L/D > 1500, but approaches higher values at smaller L/D. The dimensionless analytical expression developed for calculating the friction number and the temperature rise for water flows in micro-tubes is in good agreement with both the numerical and experimental results.


2020 ◽  
Vol 310 ◽  
pp. 00054
Author(s):  
Miroslaw Wieczorek

The paper presents the numerical analysis of the impact of removing a corner column on the behavior of a continuous slab-column structure. The model uses the minimal reinforcement amount compliant with Eurocodes. The basis for numerical modelling was the experimental research of a piece of a slab-column structure with the dimensions of 3.0×3.0 m in column axes. The article includes a detailed description of the assumed conditions of the model support, the method of loading and reading of the results. The paper also compares the obtained results of numerical calculations with experimental results.


2002 ◽  
Vol 242-245 ◽  
pp. 291-293 ◽  
Author(s):  
G.V. Kurlyandskaya ◽  
J.L. Muñoz ◽  
J.M. Barandiarán ◽  
A. Garcı́a-Arribas ◽  
A.V. Svalov ◽  
...  

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