scholarly journals Electron paramagnetic resonance in organic binder aging in dispersely reinforced substructures

2021 ◽  
Vol 23 (6) ◽  
pp. 179-189
Author(s):  
V. N. Lukashevich ◽  
O. D. Lukashevich ◽  
R. I. Mokshin
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Crack Formation ◽  
Oil Products ◽  
Organic Binder ◽  
Paramagnetic Centers ◽  
Paramagnetic Resonance ◽  
Dispersion System ◽  
Binder Aging ◽  
Mineral Mixtures ◽  
Electron Paramagnetic

Purpose: To study the intensity of binder aging in organo-mineral mixtures using electron paramagnetic resonance. The aging intensity of the organic binder is provided by its concentration in paramagnetic centers, since asphaltenes are almost one hundred percent of paramagnet concentration and indicate to the aging intensity of the petroleum dispersion system.Approach: Dispersed reinforcement of substructures with chemical fibers made of spent sorbents containing a controlled amount of absorbed oil products allows to partially solve the problem of crack formation and fracture of road pavements designed in accordance with the regulatory documents.Research implications: The service life of substructure made of dispersely reinforced organo-mineral mixtures reduces owing to organic binder aging, which begins at the stage of preparation of organo-mineral mixtures and continues during the substructure operation. Organic binder ageing results in the formation of solvation layers on the surface of mineral materials that become more viscous and brittle.Findings: The substructure dispersed reinforcement with chemical fibers made of spent sorbents containing a controlled amount of absorbed oil products decreases the concentration of paramagnetic centers. This indicates to a decrease in the asphaltene concentration, thereby reducing the aging intensity of the oil dispersion system.

Electron paramagnetic resonance study of paramagnetic centers in carbon-fumed silica adsorbent

2014 ◽  
Vol 115 (13) ◽  
pp. 133704 ◽  
Author(s):  
D. V. Savchenko ◽  
B. D. Shanina ◽  
E. N. Kalabukhova ◽  
A. A. Sitnikov ◽  
V. S. Lysenko ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Fumed Silica ◽  
Electron Paramagnetic Resonance Study ◽  
Paramagnetic Centers ◽  
Paramagnetic Resonance ◽  
Silica Adsorbent ◽  
Electron Paramagnetic

scholarly journals Особенности высокочастотного спектрометра электронного парамагнитного резонанса с модуляцией частоты

2020 ◽  
Vol 46 (9) ◽  
pp. 47
Author(s):  
Р.А. Бабунц ◽  
А.С. Гурин ◽  
Ю.А. Успенская ◽  
Г.Р. Асатрян ◽  
Д.О. Толмачев ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Fine Structure ◽  
Frequency Modulation ◽  
High Frequency ◽  
Garnet Crystal ◽  
Paramagnetic Centers ◽  
Paramagnetic Resonance ◽  
Fine Structure Splitting ◽  
Structure Splitting ◽  
Electron Paramagnetic

A high-frequency electron paramagnetic resonance (EPR) spectrometer with frequency modulation was developed. The advantages of the method for recording the EPR spectra of paramagnetic centers with giant fine-structure splitting in the case of non-Kramers ions in a garnet crystal were demonstrated.

scholarly journals Electron paramagnetic resonance in the research of defect formation and thermal processes during grinding of ZnO powders

2004 ◽  
Vol 36 (2) ◽  
pp. 65-72 ◽  
Author(s):  
M. Kakazey ◽  
M. Vlasova ◽  
M. Dominguez-Patiño ◽  
G. Dominguez-Patiño ◽  
T. Sreckovic ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Mechanical Treatment ◽  
Defect Formation ◽  
Thermal Processes ◽  
Defect Structures ◽  
Paramagnetic Centers ◽  
Paramagnetic Resonance ◽  
Zno Powders ◽  
Electron Paramagnetic

This work shows some possibilities for using electron paramagnetic resonance in an experimental study of the role of mechanothermal effects in the formation of defect structures in dispersed systems during prolonged mechanical treatment of ZnO powders. The use of EPR for this purpose is based on the known fact that initiation of a number of paramagnetic centers occurs during mechanical treatment of some materials. Such centers can serve as EPR-sondes of different thermal processes appearing during mechanical treatment of systems containing ZnO.

Electron paramagnetic resonance of radiation-induced paramagnetic centers in an aerogel

JETP Letters ◽  
2008 ◽  
Vol 88 (4) ◽  
pp. 244-248 ◽  
Author(s):  
G. V. Mamin ◽  
A. A. Rodionov ◽  
M. S. Tagirov ◽  
D. A. Tayurskii ◽  
N. Mulders
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Paramagnetic Centers ◽  
Paramagnetic Resonance ◽  
Radiation Induced ◽  
Electron Paramagnetic

scholarly journals EPR Study of Paramagnetic Centers in Human Blood

2013 ◽  
Vol 36 (1) ◽  
pp. 7-13 ◽  
Author(s):  
Tomasz Kubiak ◽  
Ryszard Krzyminiewski ◽  
Bernadeta Dobosz
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Healthy Volunteers ◽  
High Spin ◽  
Human Blood ◽  
Iron Complex ◽  
Disease Entity ◽  
Paramagnetic Centers ◽  
Paramagnetic Resonance ◽  
X Band ◽  
Electron Paramagnetic

Abstract Electron paramagnetic resonance investigations of paramagnetic centers in whole human blood were carried out at 170 K using X-band EPR spectrometer. The study included a group of patients and healthy volunteers. The EPR signals from high spin Fe3+ ions in transferrin (g = 4.2) and Cu2+ ions in ceruloplasmin (g = 2.05) are characteristic of each frozen blood sample. An overview of all recorded spectra revealed in several cases additional lines derived from high spin Fe3+ ions in methemoglobin (g = 5.8 - 6), free radicals (g = 2.002 - 2.005) and various low spin ferriheme complexes (g = 2.21 - 2.91). The lines from cytochromes (g = 3.03 and 3.27) were observed only twice. The EPR measurements have not confirmed the correlation between the occurrence of a particular type of low-spin iron complex and a specific disease entity. Moreover, the presence of EPR lines from trivalent iron also did not differentiate patients from healthy volunteers.

Defect Structure of Nanosized Zirconium Oxide Powders Doped with Y2O3, Sc2O3, Cr2O3

2013 ◽  
Vol 200 ◽  
pp. 108-113
Author(s):  
Lesya P. Yurchenko ◽  
Igor P. Bykov ◽  
Alexander B. Brik ◽  
Oleksandr D. Vasylyev ◽  
Valeriy G. Vereschak ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Zirconium Oxide ◽  
Defect Structure ◽  
Formation Mechanisms ◽  
Paramagnetic Centers ◽  
Thermal Generation ◽  
Paramagnetic Resonance ◽  
Temperature Range ◽  
Oxide Powders ◽  
Electron Paramagnetic

The formation mechanisms of paramagnetic centers originating from Zr3+ and Cr3+ ions and the influence of the nanoparticle composition on thermal generation processes of these paramagnetic centers in ZrO2 structure were studied by electron paramagnetic resonance. A set of nanosized zirconium oxide powders (nominally pure ZrO2, ZrO2 doped with correspondingly Y2O3 and Sc2O3, Cr2O3 and Y2O3, as well as Cr2O3) was investigated: The influence of annealing on the EPR lines of Zr3+ and Cr5+ ions was found to be different. Annealing curves of EPR signals caused by Cr5+ ions have a maximum in temperature range 500–600 °C. Mechanisms of Zr3+ and Cr5+ ions formation were discussed.

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