scholarly journals Detection of undistorted continuous wave (CW) electron paramagnetic resonance (EPR) spectra with non-adiabatic rapid sweep (NARS) of the magnetic field

2011 ◽  
Vol 211 (2) ◽  
pp. 228-233 ◽  
Author(s):  
Aaron W. Kittell ◽  
Theodore G. Camenisch ◽  
Joseph J. Ratke ◽  
Jason W. Sidabras ◽  
James S. Hyde
Keyword(s):  
Magnetic Field ◽  
Electron Paramagnetic Resonance ◽  
Continuous Wave ◽  
Epr Spectra ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic ◽  
The Magnetic Field

Effects of Possible Spin-Spin Interactions on EPR spectra of Cu2+ exchanged Faujasite–X (I)

2005 ◽  
Vol 900 ◽  
Author(s):  
Chrispin B. O. Kowenje ◽  
Barry R. Jones ◽  
Charles W. Kanyi
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Continuous Wave ◽  
Recent Literature ◽  
Epr Spectra ◽  
Spin Hamiltonian ◽  
Epr Spectrum ◽  
Paramagnetic Resonance ◽  
Spin Interactions ◽  
Electron Paramagnetic

ABSTRACTThe interpretation of the continuous wave electron paramagnetic resonance (CW-EPR) spectra of Cu2+ exchanged in Faujasite zeolite is not straightforward. Recent literature points to the role of both Cu2+ zeolite sites and Cu2+ relationship to lattice Al in determining the parameters of Cu2+ spin Hamiltonian. Our work shows that at low concentration, Cu2+ EPR signals show negligible spin-spin interactions. At higher Cu (II) concentrations, a third CW-EPR spectrum that has contributions from both the CW-EPR and the spin-spin interactions, appears.

Dating of Sediments by physics methods Electron Paramagnetic Resonance (EPR) in the region of Iguape – Cananéia, Brazil.

2021 ◽  
Vol 9 (1A) ◽  
Author(s):  
Bruna Cortez
Keyword(s):  
Magnetic Field ◽  
Electron Paramagnetic Resonance ◽  
Sea Level ◽  
Energy Difference ◽  
Current Control ◽  
Sediment Dating ◽  
Quaternary Period ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic ◽  
The Magnetic Field

Dating of sediments was used by physics method in this work, in the physics methods the radioactivity is present, but usually it is method based on the storage of energy of radiation in the solid, in which will be employed. In the present work, Icapara sediment dating was used Electron Paramagnetic Resonance (EPR) method, in this technique the energy absorption occurs when the frequency of the incident wave is in resonance with the energy difference made by the magnetic field between the parallel and antiparallel directions to this field with the irradiated sample that creates defects in its structure.  In the state of S˜ao Paulo, in the region of Iguape on the southeast coast, it is a place called Icapara, a large sand terrace that was formed due to sea level fluctation that ocorred more than 130 thousand years ago. A sample was taken from a point about 9 meters above the current control of the sea. An age of about 38,000 ±12,000 and 46,000 ± 7,000 years were obtained (EPR) to correlate with the Quaternary period and will be presented to the data obtained.

Electron Paramagnetic Resonance of Radicals Formed during Milling

1960 ◽  
Vol 33 (2) ◽  
pp. 462-468 ◽  
Author(s):  
S. E. Bresler ◽  
S. N. Zhurkov ◽  
E. N. Kazbekov ◽  
E. M. Saminskiĭ ◽  
E. E. Tomashevskiĭ
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Gamma Rays ◽  
Epr Spectra ◽  
Mechanical Degradation ◽  
Present Communication ◽  
Surface Layers ◽  
Paramagnetic Resonance ◽  
Mechanical Destruction ◽  
Electron Paramagnetic

Abstract It is well known that during the mechanical degradation of polymers there takes place scission of molecular chains and the formation of macroradicals. It is of considerable interest to study the electron paramagnetic resonance (EPR) spectra of the macroradicals produced by milling, and to compare them with the spectra of the macroradicals formed in the process of polymerization, and also during the irradiation of polymers by gamma rays and neutrons. We may endeavor to compare the amount of macroradicals formed with the extent of mechanical destruction (for instance with the area of the new interface which is formed). In addition, as was found by experience, the macroradicals formed by mechanical scission are good models for the investigation of reactivity since practically all of them are in the newly formed surface layers and are therefore very accessible to various chemical influences. They enter easily into reaction with various agents present in the medium since in this process diffusion from the surface is found in practice not to be a predominating factor. In the present communication we give the first EPR results obtained on mechanically degraded polymers.

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