Mössbauer Study of Iron Minerals Formed by Dissimilatory Bacterium

2009 ◽  
Vol 152-153 ◽  
pp. 431-434 ◽  
Author(s):  
N.I. Chistyakova ◽  
V.S. Rusakov ◽  
Yu.A. Koksharov ◽  
D.G. Zavarzina ◽  
Jean Marc Greneche
Keyword(s):  
Magnetic Field ◽  
Magnetic Resonance ◽  
Electron Magnetic Resonance ◽  
Mössbauer Study ◽  
Iron Reducing Bacteria ◽  
Iron Minerals ◽  
Mössbauer Measurements ◽  
Kinetics Of Formation ◽  
Reducing Bacteria ◽  
Kinetics Of

The kinetics of formation of iron-containing minerals by thermophilic dissimilatory iron-reducing bacteria Themincola ferriacetica (strain Z-0001) has been investigated by Mössbauer spectroscopy. The Mossbauer measurements were performed at room and low (77 and 4.2 K) temperatures and in a magnetic field of 6 T. Electron magnetic resonance (EМR) measurements were also carried out.

Efficient phosphate recovery as vivianite: Synergistic effect of iron minerals and microorganism

2022 ◽  
Author(s):  
Yongsheng Lu ◽  
Wei Feng ◽  
Hui Liu ◽  
Chen Chen ◽  
Yunfeng Xu ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Phosphorus Recovery ◽  
Phosphorus Pollution ◽  
Iron Reducing Bacteria ◽  
Iron Minerals ◽  
Phosphate Recovery ◽  
Reducing Bacteria

Vivianite is a promising phosphorus recovery solution that has the potential to simultaneously relieve the phosphorus shortage and phosphorus pollution. By producing vivianite, dissimilatory iron reducing bacteria may substantially enhance...

Electron magnetic resonance of ferrofluids: Evidence for anisotropic resonance at 77 K in samples cooled in a magnetic field

1995 ◽  
Vol 149 (1-2) ◽  
pp. 64-66 ◽  
Author(s):  
M.D. Sastry ◽  
Y. Babu ◽  
P.S. Goyal ◽  
R.V. Mehta ◽  
R.V. Upadhyay ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Resonance ◽  
Electron Magnetic Resonance

Mössbauer and Magnetic Study of Solid Phases Formed by Dissimilatory Iron-Reducing Bacteria

2012 ◽  
Vol 190 ◽  
pp. 721-724 ◽  
Author(s):  
N.I. Chistyakova ◽  
V.S. Rusakov ◽  
A.A. Shapkin ◽  
P.A. Pigalev ◽  
A.P. Kazakov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Liquid Nitrogen ◽  
Temperature Interval ◽  
Zero Field ◽  
Iron Reducing Bacteria ◽  
Solid Phases ◽  
Reducing Bacteria ◽  
Zero Field Cooling ◽  
Field Cooling

Mössbauer investigations of solid phases that were formed during the reduction of amorphous synthesized ferrihydrite (SF) by thermophilic anaerobic iron-reducing bacterium Thermincola ferriacetica (strain Z-0001) and alkaliphilic anaerobic iron-reducing bacterium Geoalkalibacter ferrihydriticus (strain Z-0531) were carried out at room, liquid nitrogen and helium temperatures in the presence or the absence of an external magnetic field (6 T). The magnetization M (T, H) was measured in the temperature interval 80-300 K and magnetic field up to 10 kOe. It was performed zero field cooling (ZFC) and field cooling (FC) measurements of M (T).

scholarly journals Effect of thermal formation/dissociation cycles on the kinetics of formation and pore-scale distribution of methane hydrates in porous media: a magnetic resonance imaging study

2021 ◽  
Vol 5 (5) ◽  
pp. 1567-1583 ◽  
Author(s):  
Mehrdad Vasheghani Farahani ◽  
Xianwei Guo ◽  
Lunxiang Zhang ◽  
Mingzhao Yang ◽  
Aliakbar Hassanpouryouzband ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Hydrate Formation ◽  
Imaging Study ◽  
Magnetic Resonance Imaging Study ◽  
Resonance Imaging ◽  
Natural Sediment ◽  
Thermally Induced ◽  
Kinetics Of Formation ◽  
Kinetics Of

A magnetic resonance imaging study was conducted to explore the kinetics and spatial characteristics of the thermally induced methane hydrate formation in both synthetic and natural sediment samples.

Spectroscopic imaging of human disease

1996 ◽  
Vol 54 ◽  
pp. 884-885
Author(s):  
D.J. Meyerhoff
Keyword(s):  
Magnetic Field ◽  
Magnetic Resonance ◽  
Field Gradient ◽  
Human Disease ◽  
Morphological Changes ◽  
Magnetic Field Gradient ◽  
Spectroscopic Imaging ◽  
Resonance Spectroscopy ◽  
Tissue Water

Magnetic Resonance Imaging (MRI) observes tissue water in the presence of a magnetic field gradient to study morphological changes such as tissue volume loss and signal hyperintensities in human disease. These changes are mostly non-specific and do not appear to be correlated with the range of severity of a certain disease. In contrast, Magnetic Resonance Spectroscopy (MRS), which measures many different chemicals and tissue metabolites in the millimolar concentration range in the absence of a magnetic field gradient, has been shown to reveal characteristic metabolite patterns which are often correlated with the severity of a disease. In-vivo MRS studies are performed on widely available MRI scanners without any “sample preparation” or invasive procedures and are therefore widely used in clinical research. Hydrogen (H) MRS and MR Spectroscopic Imaging (MRSI, conceptionally a combination of MRI and MRS) measure N-acetylaspartate (a putative marker of neurons), creatine-containing metabolites (involved in energy processes in the cell), choline-containing metabolites (involved in membrane metabolism and, possibly, inflammatory processes),

Nuclear magnetic resonance microscopy

1989 ◽  
Vol 47 ◽  
pp. 828-829
Author(s):  
Paul C. Lauterbur
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Fields ◽  
Signal To Noise ◽  
Field Gradients ◽  
Useful Signal ◽  
Magnetic Field Gradients ◽  
Observation Times ◽  
Nuclear Magnetic

Nuclear magnetic resonance imaging can reach microscopic resolution, as was noted many years ago, but the first serious attempt to explore the limits of the possibilities was made by Hedges. Resolution is ultimately limited under most circumstances by the signal-to-noise ratio, which is greater for small radio receiver coils, high magnetic fields and long observation times. The strongest signals in biological applications are obtained from water protons; for the usual magnetic fields used in NMR experiments (2-14 tesla), receiver coils of one to several millimeters in diameter, and observation times of a number of minutes, the volume resolution will be limited to a few hundred or thousand cubic micrometers. The proportions of voxels may be freely chosen within wide limits by varying the details of the imaging procedure. For isotropic resolution, therefore, objects of the order of (10μm) may be distinguished.Because the spatial coordinates are encoded by magnetic field gradients, the NMR resonance frequency differences, which determine the potential spatial resolution, may be made very large. As noted above, however, the corresponding volumes may become too small to give useful signal-to-noise ratios. In the presence of magnetic field gradients there will also be a loss of signal strength and resolution because molecular diffusion causes the coherence of the NMR signal to decay more rapidly than it otherwise would. This phenomenon is especially important in microscopic imaging.

Kinetics of cyclization of S-ethoxycarbonylmethylisothiouronium chloride to 2-imino-4-thiazolidone

1979 ◽  
Vol 44 (3) ◽  
pp. 912-917 ◽  
Author(s):  
Vladimír Macháček ◽  
Said A. El-bahai ◽  
Vojeslav Štěrba
Keyword(s):  
Hydrochloric Acid ◽  
Dilute Hydrochloric Acid ◽  
Base Catalysis ◽  
General Base ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Kinetics Of Formation ◽  
Acid Catalyzed ◽  
Rate Limiting ◽  
Kinetics Of

Kinetics of formation of 2-imino-4-thiazolidone from S-ethoxycarbonylmethylisothiouronium chloride has been studied in aqueous buffers and dilute hydrochloric acid. The reaction is subject to general base catalysis, the β value being 0.65. Its rate limiting step consists in acid-catalyzed splitting off of ethoxide ion from dipolar tetrahedral intermediate. At pH < 2 formation of this intermediate becomes rate-limiting; rate constant of its formation is 2 . 104 s-1.

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