Ultraviolet Spectral Behavior of UX Ari with Periodic Flaring Activity

The application of pyrometry to retrieve particle temperature in particulate-generating flames strictly requires the knowledge of the spectral behavior of emissivity of light-emitting particles. Normally, this spectral behavior is considered time-independent. The current paper challenges this assumption and explains why the emissivity of oxide nanoparticles formed in flame can change with time. The suggested phenomenon is related to transitions of electrons between the valence and conduction energy bands in oxides that are wide-gap dielectrics. The emissivity change is particularly crucial for the interpretation of fast processes occurring during laser-induced experiments. In the present work, we compare the response of titania particles produced by a flame spray to the laser irradiation at two different excitation wavelengths. The difference in the temporal behavior of the corresponding light emission intensities is attributed to the different mechanisms of electron excitation during the laser pulse. Interband transitions that are possible only in the case of the laser photon energy exceeding the titania energy gap led to the increase of the electron density in the conduction band. Relaxation of those electrons back to the valence band is the origin of the observed emissivity drop after the UV laser irradiation.

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Spectral behavior of amplified back-scattered Stokes pulse in two-cell phase conjugating mirror

Optics Communications ◽

10.1016/j.optcom.2014.08.066 ◽

2015 ◽

Vol 335 ◽

pp. 7-15 ◽

Cited By ~ 1

Author(s):

M. Jaberi ◽

A.H. Farahbod ◽

H. Rahimpour Soleimani

Keyword(s):

Spectral Behavior ◽

Stokes Pulse

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ChemInform Abstract: Synthesis and Spectral Behavior of 5-Methyl-3-phenyl-1,3-oxazolidin-2- ones Using NMR.

ChemInform ◽

10.1002/chin.198725135 ◽

1987 ◽

Vol 18 (25) ◽

Author(s):

T. NISHIYAMA ◽

S. MATSUI ◽

F. YAMADA

Keyword(s):

Spectral Behavior

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On the Spectral Behavior of an Ionic Styryl Dye: Effect of Micelle−Polyethylene-block-polyethylene Glycol Diblock Copolymer Assembly

The Journal of Physical Chemistry B ◽

10.1021/jp906221k ◽

2009 ◽

Vol 113 (41) ◽

pp. 13560-13565 ◽

Cited By ~ 13

Author(s):

Dibakar Sahoo ◽

Prosenjit Bhattacharya ◽

Sankar Chakravorti

Keyword(s):

Polyethylene Glycol ◽

Diblock Copolymer ◽

Spectral Behavior ◽

Styryl Dye ◽

Copolymer Assembly

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Use of data mining and spectral profiles to differentiate condition after harvest of coffee plants

Engenharia Agrícola ◽

10.1590/s0100-69162012000100019 ◽

2012 ◽

Vol 32 (1) ◽

pp. 184-196 ◽

Cited By ~ 2

Author(s):

Rubens A. C. Lamparelli ◽

Jerry A. Johann ◽

Éder R. dos Santos ◽

Julio C. D. M. Esquerdo ◽

Jansle V. Rocha

Keyword(s):

Data Mining ◽

Expectation Maximization ◽

Spectral Behavior ◽

Use Of Data ◽

Spectral Profiles ◽

Coffee Plants ◽

Using Data ◽

Hyperion Image ◽

Noise Fraction ◽

Behavior Profiles

This study aimed at identifying different conditions of coffee plants after harvesting period, using data mining and spectral behavior profiles from Hyperion/EO1 sensor. The Hyperion image, with spatial resolution of 30 m, was acquired in August 28th, 2008, at the end of the coffee harvest season in the studied area. For pre-processing imaging, atmospheric and signal/noise effect corrections were carried out using Flaash and MNF (Minimum Noise Fraction Transform) algorithms, respectively. Spectral behavior profiles (38) of different coffee varieties were generated from 150 Hyperion bands. The spectral behavior profiles were analyzed by Expectation-Maximization (EM) algorithm considering 2; 3; 4 and 5 clusters. T-test with 5% of significance was used to verify the similarity among the wavelength cluster means. The results demonstrated that it is possible to separate five different clusters, which were comprised by different coffee crop conditions making possible to improve future intervention actions.

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