scholarly journals Neutron imaging of liquid-liquid systems containing paramagnetic salt solutions

2020 ◽  
Vol 116 (2) ◽  
pp. 022405
Author(s):  
T. A. Butcher ◽  
G. J. M. Formon ◽  
P. Dunne ◽  
T. M. Hermans ◽  
F. Ott ◽  
...  
Keyword(s):  
Neutron Imaging ◽  
Salt Solutions ◽  
Liquid Systems ◽  
Paramagnetic Salt

Investigation of solvation effects on iron(II) and iron(III) salt solutions by X-ray absorption spectroscopy

2017 ◽  
Vol 95 (11) ◽  
pp. 1170-1177
Author(s):  
Aimee Maclennan ◽  
Yongfeng Hu
Keyword(s):  
Fine Structure ◽  
Electronic Properties ◽  
Absorption Spectroscopy ◽  
Reference Materials ◽  
Salt Solutions ◽  
X Ray ◽  
Iron Salts ◽  
Liquid Systems ◽  
X Ray Absorption

The effects of solvation on iron salts has been studied by in situ X-ray absorption spectroscopy (XAS). It was seen that the solvated iron is significantly different from the solid precursor when dissolved in a variety of common solvents. Changes in the chemical and electronic properties of the solvated species make it essential to understand what is happening in solution prior to choosing appropriate reference materials for the interpretation of X-ray absorption near edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS) data. An understanding of the complexity of analyzing liquid systems by XAS is gained from this research.

scholarly journals Indirekte Bestimmung kurzer Relaxationszeiten von paramagnetischen Ionen in wäßriger Lösung

1969 ◽  
Vol 24 (3) ◽  
pp. 424-427
Author(s):  
K. Glemser ◽  
U. Haeberlen ◽  
R. Hausser
Keyword(s):  
Relaxation Times ◽  
Dipolar Interaction ◽  
Rare Earth Ions ◽  
Proton Relaxation ◽  
Salt Solutions ◽  
Epr Spectrum ◽  
Relaxation Measurements ◽  
Paramagnetic Salt ◽  
The Difference ◽  
Diamagnetic Salt

AbstractThe width of the first Hfs-line of the Mn++ EPR-spectrum in aqueous solutions with added diamagnetic and paramagnetic iron group or rare earth ions was measured at 3 cm wavelength and at 300 °K. The difference ΔHD in linewidth of Mn++ in the paramagnetic and diamagnetic salt solutions is ascribed to dipolar interaction between Mn++ and the other paramagnetic ions e. g. Co++ , Ni++ and Ce3+ . The relaxation times τs of these ions are too short for the EPR-spectrum to be detected in liquids. From the excess linewidth ΔHD relaxation times Ts for Co++ , Ni++ and Ce3+ are estimated which agree well with τs results from proton relaxation measurements in paramagnetic salt solutions.

Isomorphous replacement in electron diffraction of wet crystals of rat hemoglobin

1983 ◽  
Vol 41 ◽  
pp. 446-447
Author(s):  
William F. Tivol ◽  
Murray Vernon King ◽  
D. F. Parsons
Keyword(s):  
Electron Diffraction ◽  
Heavy Atom ◽  
Isomorphous Substitution ◽  
X Ray Diffraction ◽  
Salt Solutions ◽  
X Ray ◽  
Isomorphous Replacement ◽  
Structure Factors ◽  
Diffraction Structure ◽  
The Mean

Feasibility of isomorphous substitution in electron diffraction is supported by a calculation of the mean alteration of the electron-diffraction structure factors for hemoglobin crystals caused by substituting two mercury atoms per molecule, following Green, Ingram & Perutz, but with allowance for the proportionality of f to Z3/4 for electron diffraction. This yields a mean net change in F of 12.5%, as contrasted with 22.8% for x-ray diffraction.Use of the hydration chamber in electron diffraction opens prospects for examining many proteins that yield only very thin crystals not suitable for x-ray diffraction. Examination in the wet state avoids treatments that could cause translocation of the heavy-atom labels or distortion of the crystal. Combined with low-fluence techniques, it enables study of the protein in a state as close to native as possible.We have undertaken a study of crystals of rat hemoglobin by electron diffraction in the wet state. Rat hemoglobin offers a certain advantage for hydration-chamber work over other hemoglobins in that it can be crystallized from distilled water instead of salt solutions.

Bulk standards for low-temperature biological x-ray microanalysis

1984 ◽  
Vol 42 ◽  
pp. 282-283
Author(s):  
P. Echlin ◽  
M. McKoon ◽  
E.S. Taylor ◽  
C.E. Thomas ◽  
K.L. Maloney ◽  
...  
Keyword(s):  
Phase Separation ◽  
Low Temperature ◽  
Analytical Method ◽  
Salt Solutions ◽  
Absolute Concentration ◽  
Cooling Process ◽  
X Ray ◽  
The Absolute ◽  
Analytical Procedures ◽  
Electrical Conductors

Although sections of frozen salt solutions have been used as standards for x-ray microanalysis, such solutions are less useful when analysed in the bulk form. They are poor thermal and electrical conductors and severe phase separation occurs during the cooling process. Following a suggestion by Whitecross et al we have made up a series of salt solutions containing a small amount of graphite to improve the sample conductivity. In addition, we have incorporated a polymer to ensure the formation of microcrystalline ice and a consequent homogenity of salt dispersion within the frozen matrix. The mixtures have been used to standardize the analytical procedures applied to frozen hydrated bulk specimens based on the peak/background analytical method and to measure the absolute concentration of elements in developing roots.

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