Resonance Raman Spectroscopic Detection of Pyridylazo Complex Formed at Liquid–Liquid Interface in Centrifugal Liquid Membrane System

2001 ◽  
Vol 30 (12) ◽  
pp. 1238-1239 ◽  
Author(s):  
Akira Ohashi ◽  
Hitoshi Watarai
Keyword(s):  
Liquid Membrane ◽  
Resonance Raman ◽  
Membrane System ◽  
Liquid Interface ◽  
Raman Spectroscopic

UV resonance Raman spectroscopic study of photodegradation of hardwood and softwood lignins by UV laser

Holzforschung ◽  
2008 ◽  
Vol 62 (2) ◽  
pp. 183-188 ◽  
Author(s):  
Krishna K. Pandey ◽  
Tapani Vuorinen
Keyword(s):  
Lignin Degradation ◽  
Laser Energy ◽  
Resonance Raman Spectroscopy ◽  
Resonance Raman ◽  
Photochemical Degradation ◽  
Raman Spectroscopic ◽  
Uv Resonance Raman ◽  
Uv Resonance Raman Spectroscopy ◽  
Ion Laser ◽  
Chir Pine

Abstract The effect of laser irradiation (Ar+ ion laser, 244 nm) on photodegradation of lignin in silver birch and rubberwood as hardwoods and spruce and chir pine as softwoods has been investigated by UV resonance Raman spectroscopy (UVRRS). UVRR spectra showed degradation of aromatic structures accompanied by the formation of both ortho- and para-quinone structures as a result of photodegradation of wood surfaces. There was a rapid decrease in the intensities of all the lignin-associated bands accompanied by broadening of aromatic bands at 1602 cm-1 and in the region of 1500–1000 cm-1 due to formation of unsaturated structures arisen from lignin degradation. The rate of lignin degradation was observed by measuring the relative intensity of aromatic band at 1602 cm-1 during photodegradation. The rates of UV-degradation of hardwood and softwood surfaces were compared and it was found that hardwoods degrade at a faster rate than softwoods. The syringyl structures in hardwood lignin are more sensitive to photochemical degradation than guaiacyl structures. The rate of photodegradation increased with increasing intensity of the irradiated laser energy.

Resonance Raman spectroscopic evidence for a common [3-iron-4-sulfur] structure among proteins containing three-iron centers

1983 ◽  
Vol 105 (22) ◽  
pp. 6671-6678 ◽  
Author(s):  
Michael K. Johnson ◽  
Roman S. Czernuszewicz ◽  
Thomas G. Spiro ◽  
James A. Fee ◽  
William V. Sweeney
Keyword(s):  
Resonance Raman ◽  
Spectroscopic Evidence ◽  
Raman Spectroscopic
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