scholarly journals Fourier transform infrared and electron spin resonance examinations of kerogen from the gunflint stromatolitic cherts (Middle Precambrian, Ontario, Canada) and related materials

2000 ◽  
Vol 65 (4) ◽  
pp. 229-244 ◽  
Author(s):  
Pavle Premovic ◽  
Goran Nikolic ◽  
Miroslav Premovic ◽  
Ivana Tonsa
Keyword(s):  
Fourier Transform ◽  
Electron Spin Resonance ◽  
Electron Spin ◽  
Strong Support ◽  
Fourier Transform Infrared ◽  
Spin Resonance ◽  
The Fourier Transform ◽  
Carbonaceous Rocks ◽  
High Level ◽  
A Minor

Kerogen occurrences in stromatolitic cherts from the Middle Precambrian Gunflint Formation and related rocks have been investigated by the use of elemental analysis, Fourier transform infrared and electron spin resonance spectroscopies. Particular attention was paid to the structural properties of the Schreiber kerogen to allow comparison with biologically controlled kerogens from Paleozoic carbonaceous rocks. The low atomic H/C ratios (0.5) of the Schreiber kerogen indicates that this material has reached a high level of maturity. The Fourier transform infrared/electron spin resonance examinations revealed that the Schreiber kerogen contains predominantly aromatic/polyaromatic structures similar to those found in mature kerogens from Paleozoic carbonaceous rocks. The evidence from this organogeochemical comparison indicates that the Schreiber kerogen and mature kerogens from Paleozoic/Mesozoic carbonaceous rocks have sufficient similarity to suggest a similar origin. Consequently, this work gives strong support to the hypothesis that if the Schreiber kerogen is of biotic origin than it is derived from the remnants of various microbial organisms (mainly phytoplanktons) including a minor contribution of subtidal (stromatolite-building) cyanobacteria.

Fourier transform electron spin resonance imaging

1991 ◽  
Vol 184 (1-3) ◽  
pp. 25-33 ◽  
Author(s):  
Uwe Ewert ◽  
Richard H. Crepeau ◽  
Curt R. Dunnam ◽  
Dajiang Xu ◽  
Sanghyuk Lee ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Electron Spin Resonance ◽  
Electron Spin ◽  
Resonance Imaging ◽  
Spin Resonance

Spectrosopic and paramagnetic properties of molybdenum oxyhydroxide films electrochemically formed from the Keggin-type (PMo12O40)3− complex

2003 ◽  
Vol 18 (10) ◽  
pp. 2509-2514 ◽  
Author(s):  
Masaharu Nakayama ◽  
Takahiro Ii ◽  
Kotaro Ogura
Keyword(s):  
Aqueous Solution ◽  
Fourier Transform ◽  
Electron Spin Resonance ◽  
Electron Spin ◽  
Photoelectron Spectroscopy ◽  
X Ray ◽  
Spin Resonance ◽  
Electrochemically Deposited ◽  
Deposited Film ◽  
Paramagnetic Properties

Molybdenum-containing films electrochemically deposited from an aqueous solution of 12-molybdphosphate (PMo12O40)3− (denoted as PMo12) have been characterized by x-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR), and electron spin resonance (ESR) techniques. XPS and FTIR data indicate that electrolysis of PMo12 leads to the formation of Mo–O–Mo linkage by condensation of the polyanions accompanied by decomposition of the phosphate moiety. The ESR spectrum of the deposited film exhibits an asymmetric signal with g ∼1.92, indicative of pentavalent molybdenum (d1). The feature of this signal is close to that for a MoV ion in the amorphous MoO3 phase, but not in the PMo12 framework. It is therefore suggested that the deposited film no longer has the Keggin structure PMo12, but consists of a continuous structure containing molybdenum oxide.

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