N-H structure in GaAsN and interaction between N-H local vibration mode and lower frequency phonon

2011 ◽  
Author(s):  
K. Ikeda ◽  
M. Inagaki ◽  
S. Wada ◽  
N. Kojima ◽  
Y. Ohshita ◽  
...  
2021 ◽  
pp. 147592172110523
Author(s):  
Obukho E Esu ◽  
Ying Wang ◽  
Marios K Chryssanthopoulos

As structural systems approach their end of service life, integrity assessment and condition monitoring during late life becomes necessary in order to identify damage due to age-related issues such as corrosion and fatigue and hence prevent failure. In this paper, a novel method of level 3 damage identification (i.e. detection, localisation and quantification) from local vibration mode pair (LVMP) frequencies is introduced. Detection is achieved by observation of LVMP frequencies within any of the vibration modes investigated while the location of the damage is predicted based on the ranking order of the LVMP frequency ratios and the damage is quantified in terms of material volume loss from pre-established quantification relations. The proposed method which is baseline-free (in the sense that it does not require vibration-based assessment or modal data from the undamaged state of the pipe) and solely frequency-dependent was found to be more than 90% accurate in detecting, locating and quantifying damage through a numerical verification study. It was also successfully assessed using experimental modal data obtained from laboratory tests performed on an aluminium pipe with artificially inflicted corrosion-like damage underscoring a novel concept in vibration-based damage identification for pipes.


2017 ◽  
Vol 95 (13) ◽  
Author(s):  
Jiraroj T-Thienprasert ◽  
Adisak Boonchun ◽  
Pakpoom Reunchan ◽  
Sukit Limpijumnong

2014 ◽  
Vol 24 (3S1) ◽  
pp. 136-142 ◽  
Author(s):  
Tran Thi Hong ◽  
Phan Tien Dung ◽  
Vu Xuan Quang

In this work, the structural characteristic and photoluminescence properties of Eu\(^{3 + }\) doped B\(_{2}\)O\(_{3}\)-TeO\(_{2}\) -ZnO-Na\(_{2}\)O glasses were investigated. These glasses were prepared by a melting method in air, combined with thermal annealing at 350\(^{\circ}\)C, 450\(^{\circ}\)C and 550\(^{\circ}\)C for different duration times. The structural analysis results of these glasses revealed the formation of micro-crystals in the annealed host glass. The photoluminescence spectra of Eu\(^{3 + }\) doped in these samples were observed. The local vibration mode around Eu\(^{3 + }\) ions was investigated by the phonon side-band (PSB) associated with \(^{7}\!F_{0}-^{5}D_{2}\) transition of Eu\(^{3+}\). Judd-Ofelt parameters were then evaluated based on photoluminescence spectra and the luminescence intensity ratios of \(^{5}D_{0} \to ^{7}\!F_{J}\) (\(J=2, 4\) and 6) to \(^{5}D_{0} \to ^{7}\!F_{1}\) transition were predicted. The obtained results were then used to calculate \(\Omega _{2},\;\Omega _{4},\; \Omega _{6} \) parameters based on Judd-Ofelt theory. These \(\Omega _{2}\), \(\Omega _{4}\), \(\Omega _{6}\) parameters allow to derive radiative properties of Eu\(^{3 + }\) ions in glass material such as transition probabilities, radiative lifetimes and peak stimulated emission cross-section for the \(^{5}D_{0} \to ^{7}\!F_{J}\) transitions.


1991 ◽  
Vol 38-41 ◽  
pp. 125-128
Author(s):  
Wei Kun Ge ◽  
Desheng Jiang ◽  
Chunying Song ◽  
Jiefei Zheng

1987 ◽  
Vol 50 (23) ◽  
pp. 1666-1668 ◽  
Author(s):  
Chunying Song ◽  
Weikun Ge ◽  
Desheng Jiang ◽  
Chenchia Hsu

2012 ◽  
Author(s):  
N. Sawaki ◽  
K. Hagiwara ◽  
K. Yamashita ◽  
N. Koide ◽  
Y. Honda ◽  
...  

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