Use of multivariate analysis for synchrotron micro-XANES analysis of iron valence state in amphiboles

2016 ◽  
Vol 101 (5) ◽  
pp. 1171-1189 ◽  
Author(s):  
M. Darby Dyar ◽  
Elly A. Breves ◽  
Mickey E. Gunter ◽  
Antonio Lanzirotti ◽  
Jonathan M. Tucker ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Valence State ◽  
Iron Valence ◽  
Xanes Analysis

The importance of the iron valence state in NiCoFe nanosheet array catalysts for the oxygen evolution reaction

2021 ◽  
Author(s):  
Hua-Shuai Hu ◽  
Yang Li ◽  
Gao Deng ◽  
Ya-Ru Shao ◽  
Ke-Xin Li ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Valence State ◽  
Nanosheet Array ◽  
Iron Valence ◽  
Catalytic Performances

The catalytic performances of NiCoFe nanosheet array catalysts for the OER are strongly dependent on the valence state of iron cations in the precursors.

The relaxation dynamics, iron valence state, and Mössbauer effect in PFN ceramics

2011 ◽  
Vol 75 (5) ◽  
pp. 731-733 ◽  
Author(s):  
A. V. Pavlenko ◽  
A. T. Kozakov ◽  
S. P. Kubrin ◽  
A. A. Pavelko ◽  
K. A. Guglev ◽  
...  
Keyword(s):  
Valence State ◽  
Mössbauer Effect ◽  
Relaxation Dynamics ◽  
Mossbauer Effect ◽  
Iron Valence

scholarly journals Effect of Heme Iron Valence State on the Conformation of Cytochromecand Its Association with Membrane Interfaces

2000 ◽  
Vol 276 (1) ◽  
pp. 153-158 ◽  
Author(s):  
Iseli L. Nantes ◽  
Maria R. Zucchi ◽  
Otaciro R. Nascimento ◽  
Adelaide Faljoni-Alario
Keyword(s):  
Valence State ◽  
Heme Iron ◽  
Membrane Interfaces ◽  
Iron Valence

Iron valence state of fine-grained material from the Jupiter family comet 81P/Wild 2 – A coordinated TEM/STEM EDS/STXM study

2013 ◽  
Vol 122 ◽  
pp. 1-16 ◽  
Author(s):  
Julien Stodolna ◽  
Zack Gainsforth ◽  
Hugues Leroux ◽  
Anna L. Butterworth ◽  
Tolek Tyliszczak ◽  
...  
Keyword(s):  
Valence State ◽  
Fine Grained ◽  
Fine Grained Material ◽  
Iron Valence

Normal to inverse transition in martian spinel: Understanding the interplay between chromium, vanadium, and iron valence state partitioning through a crystal-chemical lens

2015 ◽  
Vol 100 (10) ◽  
pp. 2018-2025 ◽  
Author(s):  
James J. Papike ◽  
Paul V. Burger ◽  
Aaron S. Bell ◽  
Charles K. Shearer ◽  
Loan Le ◽  
...  
Keyword(s):  
Valence State ◽  
Crystal Chemical ◽  
Iron Valence ◽  
Inverse Transition

Corrosion Behaviour of Truw Base and Reference Glasses

1983 ◽  
Vol 26 ◽  
Author(s):  
P. Van Iseghem ◽  
W. Timmermans ◽  
R. De Batist
Keyword(s):  
Valence State ◽  
Chemical Resistance ◽  
Diffusion Processes ◽  
Corrosion Behaviour ◽  
Partial Replacement ◽  
Distilled Water ◽  
Corrosion Rates ◽  
Weight Losses ◽  
Diffusion Controlled ◽  
Iron Valence

ABSTRACTThe corrosion behaviour of five TRUW base and reference glasses in distilled water has been investigated for times up to 8 months. The glasses were chosen to evaluate some of the main features of the basaltic slag as produced by the prototype FLK incinerator, i.e. the iron valence state and the relative influence of Al2O3 vs FeOx. Diffusion processes control the corrosion for times below 80 d at 90°C at the SA.V-1 value currently considered (1 cm-1), resulting in the formation of complex films enriched in Al, Fe and Mg over 200 nm thick. The partial replacement of 10 mole 7 Fe2Ox by Al2O3 improves the chemical resistance and strongly accelerates saturation of the leachate for Si, and apparently also for Na and K. The iron valencestate in the glass does not seem to influence the corrosion behaviour. When leaching at temperature up to 200°C, the surfaces of all glasses crystallize, while the corrosion rates do not decrease with time. At SA.V−1 ≠ 0.1 cm−1 , 90°C, the weight losses increase by a factor up to 10 relative to SA.V−1 ≠ 1 cm−1 , 90°C, and the initial diffusion controlled stage might be followed by matrix dissolution reactions.

Statistical analysis of classification

1966 ◽  
Vol 24 ◽  
pp. 188-189
Author(s):  
T. J. Deeming
Keyword(s):  
Multivariate Analysis ◽  
Statistical Analysis ◽  
Classification Scheme ◽  
Analytical Procedure ◽  
Narrow Band ◽  
Scientific Research ◽  
Maximum Amount ◽  
Amount Of Information

If we make a set of measurements, such as narrow-band or multicolour photo-electric measurements, which are designed to improve a scheme of classification, and in particular if they are designed to extend the number of dimensions of classification, i.e. the number of classification parameters, then some important problems of analytical procedure arise. First, it is important not to reproduce the errors of the classification scheme which we are trying to improve. Second, when trying to extend the number of dimensions of classification we have little or nothing with which to test the validity of the new parameters.Problems similar to these have occurred in other areas of scientific research (notably psychology and education) and the branch of Statistics called Multivariate Analysis has been developed to deal with them. The techniques of this subject are largely unknown to astronomers, but, if carefully applied, they should at the very least ensure that the astronomer gets the maximum amount of information out of his data and does not waste his time looking for information which is not there. More optimistically, these techniques are potentially capable of indicating the number of classification parameters necessary and giving specific formulas for computing them, as well as pinpointing those particular measurements which are most crucial for determining the classification parameters.

Valence state analysis of elements by EPMA and its application

1990 ◽  
Vol 48 (2) ◽  
pp. 230-231
Author(s):  
Chen Liqing ◽  
Liu Zuqin ◽  
Zhang Wei
Keyword(s):  
Valence State ◽  
Line Intensities ◽  
Valence States ◽  
Valence Electrons ◽  
Fe And Mn ◽  
Intensity Ratios ◽  
State Analysis

Valence state analyses of Fe and Mn in oxides by EPMA have been reported in literature. In this paper, the effects of valence state on intensity ratios ILα/IKα and ILα/ILβ of Cu, Ni, Co, Fe, Mn, Cr and their oxides, and on intensity ratios ILβ2/ILα1 and ILγ1/ILα1 of Mo, Nb, Zr and their oxides were studied. It was observed that intensity ratios change with valence states in accordance with some regularities, and these effects could be utilized for analyzing the valence states of catalysts.Valence state analysis of elements by EPMA is based on the fact that changes in the states of valence electrons in the outer shells of an atom cause corresponding changes in line intensities. The M electrons of Cu, Ni, Co, Fe, Mn, Cr and the N electrons of Mo, Nb, Zr are valence electrons. Line Kα1,2 and six lines of L are produced from the transitions of K-L2,3 and L-M or L-N respectively.

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