Evaluation of the optical properties of epitaxial lateral overgrown gallium nitride on sapphire and the role of optically active metastable defects using cathodoluminescence and photoluminescence spectroscopy

2005 ◽  
Vol 473 (2) ◽  
pp. 308-314 ◽  
Author(s):  
B.J. Ryan ◽  
D.P. Lowney ◽  
M.O. Henry ◽  
P.J. McNally ◽  
E. McGlynn ◽  
...  
2021 ◽  
Author(s):  
Mariana Sendova ◽  
José A. Jiménez

The role of nanodiamond as reductant and modifier of the optical properties of Eu-doped phosphate glasses toward photonic applications is scrutinized via optical transmission, photoluminescence spectroscopy, Raman scattering and calorimetry.


TAPPI Journal ◽  
2012 ◽  
Vol 11 (8) ◽  
pp. 51-58
Author(s):  
ANTTI HAAPALA ◽  
MIKA KÖRKKÖ ◽  
ELISA KOIVURANTA ◽  
JOUKO NIINIMÄKI

Analysis methods developed specifically to determine the presence of ink and other optically active components in paper machine white waters or other process effluents are not available. It is generally more interest¬ing to quantify the effect of circulation water contaminants on end products. This study compares optical techniques to quantify the dirt in process water by two methods for test media preparation and measurement: direct process water filtration on a membrane foil and low-grammage sheet formation. The results show that ink content values obtained from various analyses cannot be directly compared because of fundamental issues involving test media preparation and the varied methodologies used to formulate the results, which may be based on different sets of assumptions. The use of brightness, luminosity, and reflectance and the role of scattering measurements as a part of ink content analysis are discussed, along with fine materials retention and measurement media selection. The study concludes with practical tips for case-dependent measurement methodology selection.


Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2349
Author(s):  
Alain Salvador Conejo-Dávila ◽  
Marco Armando Moya-Quevedo ◽  
David Chávez-Flores ◽  
Alejandro Vega-Rios ◽  
Erasto Armando Zaragoza-Contreras

The development of anilinium 2-acrylamide-2-methyl-1-propanesulfonate (Ani-AMPS) monomer, confirmed by 1H NMR, 13C NMR, and FTIR, is systematically studied. Ani-AMPS contains two polymerizable functional groups, so it was submitted to selective polymerization either by free-radical or oxidative polymerization. Therefore, poly(anilinium 2-acrylamide-2-methyl-1-propanesulfonic) [Poly(Ani-AMPS)] and polyaniline doped with 2-acrylamide-2-methyl-1-propanesulfonic acid [PAni-AMPS] can be obtained. First, the acrylamide polymer, poly(Ani-AMPS), favored the π-stacking of the anilinium group produced by the inter- and intra-molecular interactions and was studied utilizing 1H NMR, 13C NMR, FTIR, and UV-Vis-NIR. Furthermore, poly(Ani-AMPS) fluorescence shows quenching in the presence of Fe2+ and Fe3+ in the emission spectrum at 347 nm. In contrast, the typical behavior of polyaniline is observed in the cyclic voltammetry analysis for PAni-AMPS. The optical properties also show a significant change at pH 4.4. The PAni-AMPS structure was corroborated through FTIR, while the thermal properties and morphology were analyzed utilizing TGA, DSC (except PAni-AMPS), and FESEM.


RSC Advances ◽  
2021 ◽  
Vol 11 (14) ◽  
pp. 7961-7971
Author(s):  
N. D. Vinh ◽  
P. M. Tan ◽  
P. V. Do ◽  
S. Bharti ◽  
V. X. Hoa ◽  
...  

The role of samarium (Sm) dopant on the structural, morphological, and optical properties of CdS QDs and CdS/ZnS core/shell QDs was methodically reported.


2020 ◽  
Vol 281 ◽  
pp. 121028 ◽  
Author(s):  
Saad Mabrouk Yakout ◽  
Hanan A. Mousa ◽  
Hala T. Handal ◽  
Walid Sharmoukh

2010 ◽  
Vol 247 (8) ◽  
pp. 1960-1964 ◽  
Author(s):  
Conor Hogan ◽  
Rita Magri ◽  
Rodolfo Del Sole

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