scholarly journals Impact of n,γ-irradiation on organic complexes of rare earth metals

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tatyana V. Balashova ◽  
Sergey V. Obolensky ◽  
Alexey N. Trufanov ◽  
Mikhail N. Ivin ◽  
Vasily A. Ilichev ◽  
...  
Keyword(s):  
Calculated Data ◽  
Absorbed Dose ◽  
Pulse Mode ◽  
Significant Shift ◽  
Ir Absorption ◽  
Γ Irradiation ◽  
Organic Complexes ◽  
Neutron Exposure ◽  
Mode 3 ◽  
Complexes Of Rare Earth

Abstract The complexes of La, Ce, Nd, Sm, Eu, Tb and Yb with benzoxazolyl-phenolate, benzothiazolyl-phenolate, benzoxazolyl-naphtholate, benzothiazolyl-naphtholate and 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione ligands were treated with n,γ-irradiation upon a sustained (45 h, absorbed dose of 120 krad, flux of neutrons 5·1013 n/cm2) and a pulse mode (3 ms, absorbed dose of 130 krad, flux of neutrons 3.6·1013 n/cm2). It was found that main characteristics of the compounds (shape of substance, color, IR absorption and photoluminescent spectra) have not changed. With an example of cerium complex [Ce(OON)3]2 it was revealed that the molecular structure of compounds after strong pulse irradiation also does not changed. However, computer simulations of neutron exposure on the same complexes showed significant shift of metal atoms and ligands. Possible reasons for the detected discrepancy between experimental and calculated data are discussed.

scholarly journals Radiation Resistance of a Structural Material Based on Modified Titanium Hydride

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
R. N. Yastrebinsky ◽  
V. I. Pavlenko ◽  
A. A. Karnauhov ◽  
N. I. Cherkashina ◽  
A. V. Yastrebinskaya ◽  
...  
Keyword(s):  
Structural Material ◽  
Portland Cement ◽  
Radiation Resistance ◽  
Titanium Hydride ◽  
Structural Phase ◽  
Absorbed Dose ◽  
Phase Changes ◽  
Cement Matrix ◽  
Γ Irradiation ◽  
Γ Radiation

This work investigates the radiation resistance of a structural material based on modified titanium hydride and a Portland cement in a flux of neutron and γ-radiation. An assessment of the geometric and physicomechanical properties is given, along with the surface structure of irradiated cement composites, and the phase composition of the main hydrosilicates of the hydrated cement matrix during its γ-irradiation. It is shown that the use of a shot of titanium hydride increases the radiation resistance of radiation shielding based on a cement matrix, in comparison with the unmodified shot. A composite based on a modified shot of titanium hydride retains its basic properties after γ-irradiation, at an absorbed dose of up to 10 MGy. At an absorbed dose of 2 MGy in the Portland cement matrix of a composite based on a modified shot of titanium hydride, the formation of suolunite hydrosilicates occurs. It was established using X-ray fluorescence that, in the titanium hydride, a redistribution of the electron density occurs at an absorbed dose of γ radiation of 5 MGy, caused by structural phase changes due to the ongoing dehydrogenation processes.

scholarly journals A study of the effect of the lung shape on the lung absorbed dose in six standard photon and neutron exposure geometries

2015 ◽  
Vol 50 (1) ◽  
pp. 65-72 ◽  
Author(s):  
A. Ebrahimi Khankook ◽  
H. Miri Hakimabad ◽  
L. Rafat Motavalli
Keyword(s):  
Absorbed Dose ◽  
Neutron Exposure

Laboratory Investigation into the Radiolytic Gas Generation from Rock Salt. A Study Related to the Disposal of High Level Radioactive Waste

1988 ◽  
Vol 127 ◽  
Author(s):  
Norbert Jockwer ◽  
Jörg Monig
Keyword(s):  
Dose Rate ◽  
Rock Salt ◽  
Absorbed Dose ◽  
Polar Compounds ◽  
Gas Production ◽  
Gas Generation ◽  
Γ Irradiation ◽  
Gaseous Products ◽  
Air Atmosphere ◽  
High Level

ABSTRACTSalt samples of two different mineralogical compositions were subjected to 60Co-γ-irradiation under an air-atmosphere. The resulting gaseous products were analysed from the gas phase above the salt. Additionally, the salt was subsequently heated up to 300 °C in order to liberate adsorbed, less volatile, and polar compounds. The gases CO2, CO, N2O, H2S, SO2, and Cl2 were identified whereas H2 was notably absent. The influence of various parameters, i. e. the total absorbed dose, the dose rate, and the temperature, on the radiolytic gas production was studied in some detail, increasing dose leads to increasing yields in CO2 and N2O. Carbon monoxide is radiolytically destroyed. Since CO2 and CO occur naturally in rock salt, they desorb thermally to some extent during the irradiation. The dose rate does not affect the yields, while the temperature during irradiation has a big effect on the radiolytic CO2 yields. At 250 °C and a radiation dose of 1×106 Gy a maximum CO2 yield of 70 mg gas per kg irradiated salt was observed. Upon heating the sample to 300 °C for 30 min. 47 mg per kg salt are additionally released.

scholarly journals Morphological changes of rat jejunum after whole body γ-irradiation and their impact in biodosimetry

2008 ◽  
pp. 475-479
Author(s):  
D Driák ◽  
J Österreicher ◽  
J Vávrová ◽  
Z Řeháková ◽  
Z Vilasová
Keyword(s):  
Morphological Changes ◽  
Absorbed Dose ◽  
Whole Body ◽  
Control Group ◽  
Specific Marker ◽  
Rat Jejunum ◽  
Γ Irradiation ◽  
Experimental Conditions ◽  
The North ◽  
Causal Therapy

Gastrointestinal form is the second stage of the Acute Radiation Syndrome (ARS) with a threshold dose of 8 Gy. It represents an absolutely lethal clinical-pathological unit, enteritis necrohemorrhagica (duodenitis, jejunitis, ileitis, respectively) with unknown causal therapy. The purpose of our study has been to evaluate the morphological changes in a model of radiationinduced enteritis in rats and estimate the significance of changes in biodosimetry. Wistar rats were randomly divided into 21 groups, 10 animals per group. Samples of the jejunum were taken 24, 48, 72, and 96 h after the whole-body γ-irradiation with the doses of 1, 5, 10, 15, and 20 Gy, and routinely stained with hematoxylin and eosin. Five morphometric markers – intercryptal distance, enterocytal height on the top and base of villus, length of basal lamina of 10 enterocytes and enterocytal width – in irradiated rat jejunum were examined. The results were compared with sham-irradiated control group. After lethal doses of irradiation, all morphometric parameters of jejunum significantly changed. With the exception of intercryptal distance, they might be considered as suitable biodosimetric markers under these experimental conditions. Our morphometry results in radiation-induced jejunitis are in accordance with those in other studies. We were the first who quantified morphological postirradiation changes in animal jejunum. Some of them might be used under experimental conditions. This experimental study is a predecessor of the clinical assessment of a specific marker. Under clinical practice, the sensitive biodosimetric parameter could serve as one of the guidance for evaluation of the absorbed dose in irradiated troops as well as rescue workers. This is in accordance with tasks and Standardization Agreement of the North Atlantic Treaty Organization.

Degradation of Acetaminophen in Aqueous Media by H2O2 Assisted Gamma Irradiation Process

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Murtaza Sayed ◽  
Fazal Hadi ◽  
Javed Ali Khan ◽  
Noor S. Shah ◽  
Luqman Ali Shah ◽  
...  
Keyword(s):  
Aqueous Media ◽  
Absorbed Dose ◽  
Degradation Process ◽  
Chemical Yield ◽  
Spectrophotometric Analysis ◽  
Γ Irradiation ◽  
Solution Ph ◽  
Radiation Chemical ◽  
G Value

Abstract In the present study, degradation of acetaminophen (ACT) aqueous solution was investigated up to an absorbed γ-irradiation dose of 1000 Gy. The effects of various additives on the degradation efficiency of ACT were also studied. The results showed that ACT degradation was increased with the increase of an absorbed dose. Based on spectrophotometric analysis, 82.5% degradation of the initial ACT concentration (9.98×10−5 M) was easily achieved at an absorbed dose of 1000 Gy. The decay of ACT followed pseudo-first order reaction kinetics at different initial concentrations. The radiation chemical yield (G-value) decreased with the increase of an absorbed dose, however at a specific absorbed dose G-values increased with the increase of ACT initial concentration. The addition of H2O2 in the range of 0.1–0.7% was effective for degradation of ACT. The degradation of ACT was inhibited in both acidic and basic solutions while maximium degradation effiency was acheived at nearly neautral solution pH, 7.6. The degradation process was markedly enhanced under oxidative conditions while strongly restrained under reductive conditions, which suggests the key role of oxidative radicals (˙OH) in the degradation of ACT.

Effect of γ-Irradiation on Photoluminescence of Porous Silicon

1995 ◽  
Vol 405 ◽  
Author(s):  
E. V. Astrova ◽  
V. V. Emtsev ◽  
A. A. Lebedev ◽  
D. S. Poloskin ◽  
A. D. Remenyuk ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Gamma Irradiation ◽  
Ir Absorption ◽  
Atmospheric Conditions ◽  
Γ Irradiation ◽  
Light Emitting ◽  
Evacuated Tubes ◽  
Pl Intensity ◽  
Higher Doses ◽  
Absorption Measurements

AbstractProperties of Porous Silicon (PS) subjected to gamma irradiation in an air ambient and in vacuum have been studied. Gamma-irradiation was carried out in usual room atmosphere, and in evacuated tubes. The samples of porous silicon were investigated by means of photoluminescence (PL) and infrared (IR) absorption. For the samples irradiated under atmospheric conditions, the PL intensity increases by several times as the dose increases up to 1019photons/cm2 and after that point it starts to go down. For a dose of ˜9.1019photons/cm2 the PL intensity falls by a factor of ˜50. The position of the spectrum maximum does not change, but the half-width of the spectrum increases by 2 or 3 times. In the case of gamma-irradiation in vacuum the PL intensity gradually decreases with increasing dose. IR absorption measurements showed variations of the intensity of Si-H and Si-O bands with the irradiation dose. Enhancement of PL at lower doses has been explained by irradiation assisted oxidation of PS at atmospheric conditions and its degradation at higher doses by suppresion of the light-emitting centers.

scholarly journals Effects of γ-irradiation on electrical characteristics of power vdmos transistors

2002 ◽  
Vol 2 (4) ◽  
pp. 223-233 ◽  
Author(s):  
Z. Pavlovic ◽  
Ivica Manic ◽  
Snezana Golubovic
Keyword(s):  
Experimental Data ◽  
Absorbed Dose ◽  
Drain Current ◽  
Gate Oxide ◽  
Effective Density ◽  
Analytical Relation ◽  
Model Parameters ◽  
Electrical Characteristics ◽  
Irradiation Effects ◽  
Γ Irradiation

In this paper we present the results of both experimental investigation and analytical modelling of ?-irradiation effects on basic electrical characteristics of power VDMOS transistors. First, an analytical model that yields the drain current and transconductance dependencies on gate oxide charge density is developed. The experimental data are utilized to establish an analytical relation between the absorbed dose of ?-irradiation and corresponding effective density of gate oxide charges, as well as to extract the values of model parameters. Drain current and transconductance of VDMOS devices are then modelled as the functions of irradiation dose. Finally, the results of modelling are compared with experimental data.

Effects of γ irradiation on bis(2-ethylhexyl)phosphoric acid supported by macroporous silica-based polymeric resins

2018 ◽  
Vol 106 (3) ◽  
pp. 249-258 ◽  
Author(s):  
Qiding Shu ◽  
Afshin Khayambashi ◽  
Xinpeng Wang ◽  
Xiaolong Wang ◽  
Lei Feng ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Fuel Cycle ◽  
Solid Phase ◽  
Absorbed Dose ◽  
Γ Irradiation ◽  
Macroporous Silica ◽  
Before And After ◽  
Radiation Resistant ◽  
Γ Rays ◽  
Polymeric Resins

AbstractBis(2-ethylhexyl)phosphoric acid (HDEHP) is one of the most intensively used extractants in solvent extraction, and its particular interest lies in the its application in nuclear fuel cycle as an extractant supported by macroporous silica-based polymeric resins in solid phase extraction technique. In this study, HDEHP/SiO2-P was synthesized by impregnation and immobilization, and we mainly focused on its radiation-resistant properties against γ-rays. It was found that HDEHP/SiO2-P still had good adsorption and separation properties after γ-irradiation by batch experiment. The uptake capacity of Gd(III) towards HDEHP/SiO2-P decreased slightly after irradiation. HDEHP/SiO2-P did not show any changes in the characterization of infrared spectroscopy and thermogravimetric analysis before and after irradiation. UPLC-Q-TOF-MS was employed to investigate the reaction mechanism in radiolysis of HDEHP in irradiated filter liquor. HDEHP/SiO2-P had a satisfactory radiation-resistance and chemical stability, even though it was exposed to the high absorbed dose of 500 kGy by γ-rays.

RELATIONSHIPS BETWEEN THE NATURE OF SOIL ORGANIC MATTER AND ROOT LIGNINS OF GRASSES IN A ZONAL SEQUENCE OF CHERNOZEMIC SOILS

1976 ◽  
Vol 56 (4) ◽  
pp. 363-371 ◽  
Author(s):  
L. E. LUTWICK ◽  
J. F. DORMAAR
Keyword(s):  
Thermal Decomposition ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Humic Substances ◽  
Single Species ◽  
Carboxyl Groups ◽  
Ir Absorption ◽  
Grass Roots ◽  
Organic Complexes ◽  
Ir Absorption Spectra

Clay–organic complexes, humic substances, and grass roots were separated from the Ah horizons of soils sampled at undisturbed sites in three Chernozemic soil zones from under dominantly single species of grass. Derivative thermograms (DTG) and infrared (IR) absorption spectra of the soil materials and of the lignins of the grass roots were compared. The data indicated that the organic matter (OM) of the Black soils contained fewer aliphatic groups and more carboxyl groups and was more resistant to thermal decomposition than that of the Brown soils; the OM of the Dark Brown soils was intermediate. The root lignins from the same soils showed many of the same zonal variations in the IR and DTG properties as did the soil OM.

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