scholarly journals Laser yellowing effect: study of the nanophases created by laser irradiation of synthetic black crusts using transmission electron microscopy (TEM) and electron paramagnetic resonance (EPR) spectroscopy

2017 ◽  
Author(s):  
Marie Godet ◽  
◽  
Véronique Vergès-Belmin ◽  
Christine Andraud ◽  
Mandana Saheb ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Paramagnetic Resonance ◽  
Laser Irradiation ◽  
Epr Spectroscopy ◽  
Effect Study ◽  
Paramagnetic Resonance ◽  
Black Crusts ◽  
Transmission Electron ◽  
Electron Paramagnetic

scholarly journals Mineral-polymer composites based on hydroxyapatite with polyvynylpyrrolidon for medicine

2019 ◽  
Vol 487 (3) ◽  
pp. 270-274
Author(s):  
I. V. Fadeeva ◽  
F. I. Grabovenko ◽  
A. S. Fomin ◽  
S. M. Barinov ◽  
F. F. Murzakhanov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Epr Spectroscopy ◽  
Coherent Scattering ◽  
Coherent Scattering Region ◽  
Paramagnetic Resonance ◽  
Transmission Electron ◽  
Electron Paramagnetic ◽  
Photoinduced Epr

Composites of hydroxyapatite (HA) with polyvinylpyrrolidone (PVP) were synthesized by precipitation in water solutions, mass relations of HA/PVP varied in region 3,6-14,5. The composite materials were investigated using XRD, IR, electron paramagnetic resonance (EPR) spectroscopy and transmission electron microscopy (TEM). Based on the TEM results it was found that during calcination of composites at 400 °C small agglomerates consisting of individual crystalline HA particles were formed, resulting in a particle size (according to TEM) slightly larger than coherent scattering region. Using the method of photoinduced EPR spectroscopy confirmed the presence of interaction between HA and PVP. The resulting composites can be used as materials for reconstructive surgery.

Investigation of Antioxidant Activity of Pomegranate Juices by Means of Electron Paramagnetic Resonance and UV-Vis Spectroscopy

2015 ◽  
Vol 98 (4) ◽  
pp. 866-870 ◽  
Author(s):  
Violetta Kozik ◽  
Krystyna Jarzembek ◽  
Agnieszka Jędrzejowska ◽  
Andrzej Bąk ◽  
Justyna Polak ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Free Radical ◽  
Epr Spectroscopy ◽  
Antioxidant Properties ◽  
Free Radical Scavenger ◽  
Pomegranate Juice ◽  
Radical Scavenger ◽  
Paramagnetic Resonance ◽  
Vis Spectroscopy ◽  
Electron Paramagnetic

Abstract Pomegranate fruit (Punica granatum L.) is a source of numerous phenolic compounds, and it contains flavonoids such as anthocyanins, anthocyanidins, cyanidins, catechins and other complexes of flavonoids, ellagitannins, and hydrolyzed tannins. Pomegranate juice shows antioxidant, antiproliferative, and anti-atherosclerotic properties. The antioxidant capacity (TEAC) of the pomegranate juices was measured using electron paramagnetic resonance (EPR) spectroscopy and 1,1-diphenyl-2-picrylhydrazyl (DPPH•) as a source of free radicals, and the total phenolic (TP) content was measured using UV-Vis spectroscopy. All the examined pomegranate juices exhibited relatively high antioxidant properties. The TEAC values determined by means of EPR spectroscopy using Trolox (TE) as a free radical scavenger were in the range of 463.12 to 1911.91 μmol TE/100 mL juice. The TP content measured by the Folin-Ciocalteu method, using gallic acid (GA) as a free radical scavenger, widely varied in the investigated pomegranate juice samples and ranged from 1673.62 to 5263.87 mg GA/1 L juice. The strongest antioxidant properties were observed with the fresh pomegranate juices obtained from the fruits originating from Israel, Lebanon, and Azerbaijan. Correlation analysis of numerical data obtained by means of EPR spectroscopy (TEAC) and UV-Vis spectroscopy (TP) gave correlation coefficient (r) = 0.90 and determination coefficient (r2) = 0.81 (P <0.05).

scholarly journals Chain initiation

2019 ◽  
Vol 89 (2) ◽  
pp. 179-186
Author(s):  
V. V. Ptushenko
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Epr Spectroscopy ◽  
Paramagnetic Resonance ◽  
Chain Initiation ◽  
Radio Spectroscopy ◽  
Scientific Instrumentation ◽  
History Of ◽  
Scientists And Engineers ◽  
Electron Paramagnetic

This article describes the formation of the chemical electron paramagnetic resonance (EPR) spectroscopy institute established by Academician Vladislav V. Voevodsky (1917–1967) along with the history of the development of the instrumentation basis for this field of science in the Union of Soviet Socialist Republics (USSR). The design of the first EPR spectrometers for the chemical radio spectroscopy initiated the emergence of a new scientific instrumentation field in this country. Based on recollections shared by scientists and engineers and an examination of archive materials, the author reconstructs relevant events and identifies major participants in this process.

Laser-Induced Oxidation and Crystallization of Thin Amorphous Sputtered Cr Films

1983 ◽  
Vol 29 ◽  
Author(s):  
M. I. Birjega ◽  
C. A. Constantin ◽  
M. Dinescu ◽  
I. Th. Florescu ◽  
I. N. Mihailescu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
Laser Irradiation ◽  
Dwell Time ◽  
Free Standing ◽  
Transmission Electron Diffraction ◽  
Oxidation Processes ◽  
Transmission Electron ◽  
Power Densities

ABSTRACTThe crystallization and oxidation processes of thin, free-standing (FS), sputtered Cr films under the action of cw CO2 laser irradiation were studied by transmission electron microscopy (TEM) and transmission electron diffraction (TED). The crystallization is induced at power densities above 28.65 W cm−2, dwell time of 1 s, and the oxidation at power densities of 48.1 W cm−2 and longer dwell times.

Sign in / Sign up

Export Citation Format

Share Document