scholarly journals Effect of Irradiation with Low-Energy He2+ Ions on Degradation of Structural, Strength and Heat-Conducting Properties of BeO Ceramics

Crystals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 69
Author(s):  
Maxim V. Zdorovets ◽  
Dmitriy I. Shlimas ◽  
Artem L. Kozlovskiy ◽  
Daryn B. Borgekov
Keyword(s):  
Structural Changes ◽  
Accumulation Rate ◽  
Surface Hardness ◽  
Beryllium Oxide ◽  
Low Energy ◽  
Heat Conducting ◽  
Small Contribution ◽  
Ceramic Surface ◽  
Radiation Induced ◽  
Dislocation Density Increase

The paper is devoted to the study of radiation-induced damage kinetics in beryllium oxide ceramics under irradiation with low-energy helium ions with fluences of 1015–1018 ion/cm2. It was revealed that at irradiation fluences above 1017 ion/cm2, a decrease in radiation-induced damage formation and accumulation rate is observed, which indicates the saturation effect. At the same time, the main mechanisms of structural changes caused by irradiation at these fluences are amorphization processes and dislocation density increase, while at fluences of 1015–1016 ion/cm2, the main mechanisms of structural changes are due to the reorientation of crystallites and a change in texture, with a small contribution of crystal lattice distorting factors. It was discovered that the radiation-induced damage accumulation as well as an implanted helium concentration increase leads to the surface layer destruction, which is expressed in the ceramic surface hardness and wear resistance deterioration. It was determined that with irradiation fluences of 1015–1016 ion/cm2, the decrease in thermal conductivity is minimal and is within the measurement error, while an increase in the irradiation fluence above 1017 ion/cm2 leads to an increase in heat losses by more than 10%.

А Computer Simulation of Radiation-Induced Structural Changes and Properties of Multiperiod ZrNx/MoNx System

2017 ◽  
Vol 9 (2) ◽  
pp. 02031-1-02031-5
Author(s):  
O. V. Sobol ◽  
◽  
A. A. Meylekhov ◽  
T. V. Bochulia ◽  
V. A. Stolbovoy ◽  
...  
Keyword(s):  
Computer Simulation ◽  
Structural Changes ◽  
Radiation Induced

Gamma-Ray Radiation-Induced Surface Hydrophobic Effects in Invar Alloy

2012 ◽  
Vol 482-484 ◽  
pp. 1585-1591 ◽  
Author(s):  
Cheng Fu Yang ◽  
Wei Wen Wang ◽  
Hsin Hwa Chen ◽  
Wei Tan Sun ◽  
Chi Lin Shiau ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Structural Changes ◽  
Gamma Ray ◽  
Small Deviation ◽  
Contact Angles ◽  
Invar Alloy ◽  
Hydrophobic Effects ◽  
Post Irradiation ◽  
Radiation Induced ◽  
Gamma Ray Irradiation

In this paper, we report a new phenomenon observed in the gamma-ray radiation-induced hydrophobic effects on an Invar surface: When the Invar alloy is subjected to different doses of gamma-ray irradiation, the contact angle increases with the radiation dose. Invar samples with exposed to a higher dose appear more hydrophobic, but this tendency disappears following post-irradiation etching. The contact angles of the irradiated and etched Invar samples can be restored back to a stable value with small deviation after 30 min of annealing at 150°C. X-ray diffraction (XRD) analysis found no crystalline structural changes. High resolution field emission scanning microscope (FE-SEM) analyses showed that irradiation might induce crack-like surfaces which could be removed at higher radiation dose in the following acid etchings. It is believed that the chemical bonds of Invar oxide on the surface were broken by the gamma-ray irradiation, thus raising the likelihood of binding with free ions in the air and resulting in the exclusion of the hydrophilic OH bonds, leaving a hydrophobic post-irradiation Invar surface.

Modification of Barium Cerate by Heavy Ion Irradiation

2013 ◽  
Vol 781-784 ◽  
pp. 357-361 ◽  
Author(s):  
Igor V. Khromushin ◽  
Taтiana I. Aksenova ◽  
Turgora Tuseyev ◽  
Karlygash K. Munasbaeva ◽  
Yuri V. Ermolaev ◽  
...  
Keyword(s):  
Structural Changes ◽  
Solid Phase ◽  
Ion Irradiation ◽  
Heavy Ion ◽  
High Energy ◽  
Low Energy ◽  
Barium Cerate ◽  
Weakly Bound ◽  
Ion Ranges ◽  
High Energy Ions

The effect of irradiation with heavy ions Ne, Ar, and Kr of various energies on the structure and properties of ceramic barium cerate doped with neodymium and annealed in air at 650°C for 7 hours is studied. It is noted that blistering was observed on cerate surface during its irradiation by low energy Ne ions, whereas it was not observed under low-energy Ar and Kr ions irradiation. Irradiation of the cerate with high energy ions caused partial amorphization of the irradiated surface of the material, while the structure of the non-irradiated surface did not change. In addition, the irradiated surface of the cerate endured solid-phase structural changes. Thus, upon high-energy ions irradiation in the range of Ne, Ar, Kr the cerate surface resembled the stages of spherulite formation - nucleation, growth (view of cauliflower), formation of spherulitic crust, respectively. The increase in water molecules release and reduction of molecular oxygen release from the barium cerate, irradiated by high-energy ions is found during vacuum constant rate heating. It is concluded that cerates undergo changes to the distances significantly exceeding the ion ranges in these materials. Features of high-energy ions influence on thermal desorption of carbon dioxide from cerates show, apparently, the formation of weakly bound carbonate compounds on the cerate surface in the irradiation process.

Metaphase-Based Cytogenetic Approach Identifies Radiation-Induced Chromosome and Chromatid Aberrations in Zebrafish Embryos

2021 ◽  
Author(s):  
Halida Thanveer Asana Marican ◽  
Hongyuan Shen
Keyword(s):  
Animal Model ◽  
Radiation Exposure ◽  
Progenitor Cells ◽  
Chromosome Aberrations ◽  
Structural Changes ◽  
Current Knowledge ◽  
Living Organism ◽  
Zebrafish Embryos ◽  
Radiation Induced

Metaphase-based cytogenetic methods based on scoring of chromosome aberrations for the estimation of the radiation dose received provide a powerful approach for evaluating the associated risk upon radiation exposure and form the bulk of our current knowledge of radiation-induced chromosome damages. They mainly rely on inducing quiescent peripheral lymphocytes into proliferation and blocking them at metaphases to quantify the damages at the chromosome level. However, human organs and tissues demonstrate various sensitivity towards radiation and within them, self-proliferating progenitor/stem cells are believed to be the most sensitive populations. The radiation-induced chromosome aberrations in these cells remain largely unknown, especially in the context of an intact living organism. Zebrafish is an ideal animal model for research into this aspect due to their small size and the large quantities of progenitor cells present during the embryonic stages. In this study, we employ a novel metaphase-based cytogenetic approach on zebrafish embryos and demonstrate that chromosome-type and chromatid-type aberrations could be identified in progenitor cells at different cell-cycle stages at the point of radiation exposure. Our work positions zebrafish at the forefront as a useful animal model for studying radiation-induced chromosome structural changes in vivo.

scholarly journals Radiation Induced Structural Changes in Complex Oxides

Materia Japan ◽  
2008 ◽  
Vol 47 (12) ◽  
pp. 613-613
Author(s):  
Manabu Ishimaru
Keyword(s):  
Structural Changes ◽  
Complex Oxides ◽  
Radiation Induced

scholarly journals Comprehensive model for X-ray-induced damage in protein crystallography

2019 ◽  
Vol 26 (4) ◽  
pp. 945-957 ◽  
Author(s):  
David M. Close ◽  
William A. Bernhard
Keyword(s):  
Structural Changes ◽  
Theoretical Calculations ◽  
Comprehensive Model ◽  
Additional Insight ◽  
Radiation Physics ◽  
X Ray ◽  
Fundamental Understanding ◽  
Radiation Induced ◽  
The Many ◽  
Significant Effort

Acquisition of X-ray crystallographic data is always accompanied by structural degradation owing to the absorption of energy. The application of high-fluency X-ray sources to large biomolecules has increased the importance of finding ways to curtail the onset of X-ray-induced damage. A significant effort has been under way with the aim of identifying strategies for protecting protein structure. A comprehensive model is presented that has the potential to explain, both qualitatively and quantitatively, the structural changes induced in crystalline protein at ∼100 K. The first step is to consider the qualitative question: what are the radiation-induced intermediates and expected end products? The aim of this paper is to assist in optimizing these strategies through a fundamental understanding of radiation physics and chemistry, with additional insight provided by theoretical calculations performed on the many schemes presented.

A scanning Kelvin probe for synchrotron investigations: thein situdetection of radiation-induced potential changes

2011 ◽  
Vol 19 (1) ◽  
pp. 48-53 ◽  
Author(s):  
Bekir Salgin ◽  
Dirk Vogel ◽  
Diego Pontoni ◽  
Heiko Schröder ◽  
Bernd Schönberger ◽  
...  
Keyword(s):  
High Performance ◽  
Structural Changes ◽  
Kelvin Probe ◽  
X Ray ◽  
Scanning Kelvin Probe ◽  
Wide Range ◽  
First Results ◽  
Radiation Induced ◽  
Set Up

A wide range of high-performance X-ray surface/interface characterization techniques are implemented nowadays at every synchrotron radiation source. However, these techniques are not always `non-destructive' because possible beam-induced electronic or structural changes may occur during X-ray irradiation. As these changes may be at least partially reversible, anin situtechnique is required for assessing their extent. Here the integration of a scanning Kelvin probe (SKP) set-up with a synchrotron hard X-ray interface scattering instrument for thein situdetection of work function variations resulting from X-ray irradiation is reported. First results, obtained on bare sapphire and sapphire covered by a room-temperature ionic liquid, are presented. In both cases a potential change was detected, which decayed and vanished after switching off the X-ray beam. This demonstrates the usefulness of a SKP forin situmonitoring of surface/interface potentials during X-ray materials characterization experiments.

Structural Modifications in Thin Films Caused by Gamma Radiation

2005 ◽  
Vol 480-481 ◽  
pp. 13-20 ◽  
Author(s):  
Khalil Arshak ◽  
Olga Korostynska ◽  
John Henry
Keyword(s):  
Thin Films ◽  
Gamma Radiation ◽  
Structural Changes ◽  
X Ray Diffraction ◽  
Thermal Vacuum ◽  
X Ray ◽  
Structural Modifications ◽  
Thin Oxide Films ◽  
Radiation Induced ◽  
Induced Changes

This paper reports on the gamma radiation-induced changes in thin oxide films deposited by thermal vacuum technique. Structures of various oxides thin films, such as In2O3, SiO and TeO2 and their mixtures in different proportions were studied. The influence of gamma radiation on In2O3/SiO films has resulted in significant changes in the microstructure of this film. Some kind of agglomerations with variable sizes in the range 0.5-3 µm has occurred. After a dose of 8160 µSv an evidence of partial crystallisation was observed with X-ray diffraction. Structural changes in TeO2 thin film were explored by means of Raman spectroscopy. After they have been exposed to g- radiation, a strong peak appeared at 448.83 cm-1, indicating further transformation to g-TeO2 modification.

Radiation-induced granulocyte transmigration predicts development of delayed structural changes in rat intestine

2001 ◽  
Vol 59 (1) ◽  
pp. 81-85 ◽  
Author(s):  
Konrad K. Richter ◽  
Junru Wang ◽  
Magne K. Fagerhol ◽  
Martin Hauer-Jensen
Keyword(s):  
Structural Changes ◽  
Rat Intestine ◽  
Radiation Induced
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