"Dose – effect" calibration dependence by frequency of unstable chromosomic exchanges in human lymphocytes in acute gamma irradiation by 137Сs in low doses for biological dosimetry

The calibration dependence of dicentrics and rings chromosomes with an accompanying fragment induction in human lymphocytes by in vitro 137Сs acute gamma irradiation of blood in the dose range of 0.09 - 1.0 Gy is presented. The application of the obtained calibration curve for estimation of “biological” doses for overexposed 9 persons from the contract staff of the Chornobyl SSE is shown. Their doses calculated by the frequency of dicentrics and centric rings with consideration of operation duration and mode in the zone of influence of the radiation factor, significantly exceeded the doses determined by the methods of physical dosimetry.

Pre-sowing seeds stimulation by UV-C and X-ray irradiation on the content of antioxidants in inflorescence plants genotypes Matricia chammomila L.

The differences in the dynamics of the flavonoids and phenols content in plants of eight genotypes of matricaria in the control and at presowing UV-C and X-ray irradiation of seeds were studied. Groups of genotypes by the stimulating effect on the content of antioxidants were determined mainly by UV-C irradiation, as well as groups with a significant increase in the content of antioxidants during X-ray irradiation have been identified. A high significant correlation (R = 0.84) between stimulation of flavonoid synthesis by X-ray irradiation and the level of these antioxidants in the control group is shown. Above average (R = 0.64), but insignificant, the correlation is observed between the level of flavonoids in UV-C stimulation and the level of these antioxidants in the control group. No correlation was found between the content of phenols in the control group and the increase of this indicator after irradiation.

Radionuclides contamination of leaves of woody plants growing within the CHNPP cooling pond

The data on the state of radioactive contamination of leaves of plants growing directly on the territory of the drained part of the cooling pond of the Chernobyl NPP are presented. It was shown that the main source of contamination is the root intake of radionuclides (137Cs and 90Sr). This contamination is larger in previously drained areas compared to recently exposed ones. Hot particles were found on the leaf surface by autoradiography. Their total β-activity is a few percent of the total pollution. Possible sources of hot particles – resuspension in the air in the region of the northern part of the cooling pond are discussed.

Spectral characteristics of initial and irradiated GaAsP LEDs

The optical characteristics of the GaAs1-хPх output LEDs and LEDs irradiated with electrons with Е = 2 MeV, Ф = 1015 ÷ 1016 cm-2 were studied. The width of the band gap of the GaAs1-хPх (х = 0.45) solid solution was estimated. Its growth is caused by the heating of carriers by the field of the p-n junction. The damage coefficients of the lifetime of minority charge carriers for irradiated GaAsP LEDs have been calculated and the consequences of exposure to radiation on the operational parameter Т1, which determines the thermal stability of the diodes, have been analyzed.

Spontaneous double alpha decay: First experimental limit and prospects of investigation

Nuclear decays with simultaneous emission of two alpha particles are energetically possible for a number of nuclides. Prospects of searching for such kind of decay for nuclides present in the natural isotopic composition of elements are discussed here. The first experimental limit on half-life for 2α decay is set for 209Bi as T1/2 > 2.9·1020 y at 90 % C.L., using the data of work [P. de Marcillac et al. Nature 422 (2003) 876]. Theoretical T1/2 estimations for the process are also given. Using these values, which are on the level of 1033 y or more, one can conclude that the prospects of experimental observation of 2α decay are very pessimistic.

Effects of genomic instability in populations of Drosophilae melanogaster from regions of Ukraine with different radiation impact factors

Differences in the gonadal dysgenesis frequency as an indicator of the activation of mobile elements were revealed in F1-descendants of natural populations of Drosophіla melanogaster, selected from regions of different radiation impact. Under conditions of additional low-rate chronic irradiation in laboratory conditions for 10 generations, significant differences in changes in the level and dynamics of this indicator were established depending on the accumulated dose of Drosophila populations from the city of Netishin (Khmelnytskyi NPP) and Magarach city.

Application of modern learning technologies on development of qualification in physical protection

Two training technologies, developed and implemented by the George Kuzmich Training Center for Physical Protection, Accounting and Control of Nuclear Material of the Institute for Nuclear Research of the National Academy of Sciences of Ukraine in the training process for advanced training in physical protection, are considered. The first is a training technology based on the use of the Training ground "Complex of engineering and technical means of a physical protection system", which enables students to acquire practical skills in operational management and technical operation of a complex engineering and technical means of a physical protection system. The second is a technology based on the use of the Interactive training complex "Nuclear Power Plant with elements of the physical protection system", which allows interactively checking the configurations of the nuclear power plant physical protection system proposed by the students for the presence of vulnerable routes to the targets of adversaries. The effectiveness of using these technologies in the training process is discussed, as well as the development and implementation of other modern training technologies by the Training Center.

70-th anniversary of Vasyl Ivanovych Slisenko

Brief biography and scientific achievements of Vasyl Ivanovych Slisenko in relation with his 70-th anniversary.

Erratum to: "Comments on the article: O. M. Povoroznyk, O. K. Gorpinich. Experimental observation of neutron-neutron correlations in nucleus 6He from 3H(α, pα)nn reaction"

Original article: Yaderna Fizyka ta Energetyka (Nucl. Phys. At. Energy) 22(1) (2021) 111.

Neutron investigation of interaction between anionic surfactant micelles and poly (ethylene glycol) polymer brush system

A polymer brush system of a neutral polymer poly (ethylene glycol) with a molecular weight of Mw = 20 kDa on silicon substrates in an aqueous medium was studied by the specular neutron reflectometry. Structural changes in the density profile of a polymer brush caused by the interaction of polymer chains with micelles of the anionic surfactant dodecylbenzenesulfonate acid were observed. The effect is shown to be related to the formation of molecular polymer-micelle associates in the bulk of the solution, which was previously studied by small-angle neutron scattering in a wide range of surfactant concentrations at various molecular weights of the polymer. The density of the dry polymer layer on the silicon substrate was additionally characterized by X-ray reflectometry and scanning atomic force microscopy.