On the basis of previous studies carried out by the authors of this work, it was shown that the external environment of a person has a rather strong effect on the annual intake of radon and its ...daughter decay products into the human body. In this paper, the authors have presented a computational model and its software implementation in the form of a computer program that allows calculating the accumulated doses from various radionuclides in organs and tissues of the human body. This software and mathematical complex simulates the spread of radionuclides throughout the body, taking into account the experimental coefficients of transition from one organ to another. Such a mathematical calculation, based on the experimental accumulation factors and methods for calculating the ICRP doses, makes it possible to calculate the internal radiation doses of the corresponding organs and tissues. A mathematical model has been developed for the transport and accumulation of natural radionuclides in the organs of the respiratory and digestive systems of the human body on the basis of the accumulation and transition coefficients for the corresponding organs. The visualization of the accumulated doses of a certain organ is carried out against the background of a person’s silhouette and the corresponding body system of this organ that is part of it. The degree of “highlighted” organs is normalized to the maximum doses of sanitary norms of the Republic of Kazakhstan for this organ and this radionuclide. In this simulation, the calculations of the accumulated doses from the concentrations of radionuclides in the respiratory and digestive systems of the human body are performed. This complex is designed, first of all, to perform preliminary estimated doses in organs from a wide range of radionuclides, both for diagnostic purposes and in the form of demonstration material in specialized courses at radioecological and medical centers or in higher education.
Abstract
We present the results of studies of a cold-plasma atmospheric pressure discharge in argon flow, in both DC and pulse-periodic modes. The burning voltage and the discharge current were 200 V ...and 15 mA in continuous mode; in pulse-periodic mode the voltage was 220 V and the current 15 mA for a pulse repetition rate of 100 kHz. Special attention was given to the positive column dynamics during the discharge stages of initiation, burning, and extinction. The main method of investigation employed optical diagnostics of the plasma in the visible range with high time resolution. The positive discharge column is shown to be a constricted current channel in the form of an elongated loop. In continuous mode, the length of the positive column, from anode attachment to inflection point outside the discharge system, is several millimeters. In pulsed mode, the positive column is an unsteady plasma formation, the length of which increases at about 4 m s
−1
, and reaches the same dimension over a time of order 1 ms. We find that the positive column plasma includes hydroxyl molecules OH, nitrogen N
2
, and atomic oxygen O I, along with atoms of the working gas argon. Observation of the time evolution of the optical emission from the plasma-forming gas shows that the plasma glow of the positive column is mainly determined by argon Ar I radiation, with maximum intensity at the trailing edge of the current pulse.
We present a method to determine the proton-to-helium ratio in cosmic rays at ultra-high energies. It makes use of the exponential slope, Λ, of the tail of the Xmax distribution measured by an air ...shower experiment. The method is quite robust with respect to uncertainties from modeling hadronic interactions and to systematic errors on Xmax and energy, and to the possible presence of primary nuclei heavier than helium. Obtaining the proton-to-helium ratio with air shower experiments would be a remarkable achievement.
To quantify the applicability of a particular mass-sensitive variable for mass composition analysis despite hadronic uncertainties we introduce as a metric the ‘analysis indicator’ and find an improved performance of the Λ method compared to other variables currently used in the literature. The fraction of events in the tail of the Xmax distribution can provide additional information on the presence of nuclei heavier than helium in the primary beam.
In this work, the authors describe experimental data on the angular distributions of alpha particles on light alpha-cluster nuclei. The angular distributions of elastic scattering of alpha particles ...are analyzed under the assumption of complete absorption inside the sphere of the cluster structure and the sphere of the interaction core. These assumptions made it possible to decompose the scattering amplitude into components—scattering on the nucleus itself and on different cluster structures. The calculations result in the following. The amplitude for describing diffraction elastic scattering by 4
n
± 1 light nuclei in the framework of the theory of diffraction scattering is a superposition of wave functions in the scattering approximation on a completely black core and on its absolutely black substructures. The nucleon association modes, as well as the scattering modes on the correlated motion of nucleons and spatially separated nucleons, make a significant contribution to the total scattering amplitude. This manifests itself as an increase in angular distributions due to the interference of modes of various cluster structures and nucleons. Owing to these effects, not only an uneven rise in the angular distributions of differential cross sections over the Rutherford section is possible, but also a rise at rear angles.
The operation principle of an optical aerosol sonde is based on detection of radiation scattered in a free atmosphere from a sequence of light probing pulses emitted by LEDs at two wavelengths, 470 ...and 940 nm. Like in a lidar, echo signals are synchronously accumulated simultaneously with probing pulses. Unlike in a lidar, the recorded signal is formed by the lens system of photodetectors due to radiation scattering in a light-scattering volume of ~0.1 m
3
located at short distances of ~0.2–5 m from the source. The scattered radiation entering the photodetector is not strictly backward (by 180°) as in a lidar, since the characteristic scattering angles are ~170°–180°. For a more rigorous modeling of the sonde measurement processes, with allowance for possible scattering angles, a measurement model was developed and applied based on the Monte Carlo method. To increase the signal-to-noise ratio (SNR), the optical axes of the photodetector and emitters are located at an angle of 5°, which, when using synchronous signal detection, allows one to obtain an SNR value of at least 50 at an altitude of 30 km. The probe can be easily integrated with all types of standard aerological radiosondes and, having its own navigation module and telemetry system, can also be used in autonomous flights. The all-weather aerosol backscattersonde can be used at night time for studying and monitoring polar stratospheric clouds, tropospheric and stratospheric aerosol, cirrus clouds, pyroconvection, volcanic aerosol, as well as for verifying remote methods and means of ground- and satellite-based aerosol observations. The use of the two-wave measurement technique makes it possible to reliably diagnose changes in the aerosol composition with height by the color index. In some cases, the type of aerosol is also identified. The data of probe measurements in March 2021 over Salekhard, when the temperatures of air masses inside the polar stratospheric cyclone were slightly higher than the threshold values for the formation of type I polar stratospheric clouds, are presented. Calculations of the color index indicate the dominance of sulfuric-acid aerosol at heights of 10–15 km, as well as the fact that the aerosol composition definitely changes as the height decreases, apparently due to the addition of soot particles.
At present, an urgent problem is the study of temporal variations of various types of nuclear radiation from the lithosphere in foothill and desert landscapes. This refers to the fluxes of neutrons, ...gamma quanta, beta particles, and emanations of heavy chemical elements. The problem of studying such distributions in the surface atmospheric layer of the Earth remains relevant, owing to the fact that they are concentrated in the human habitat and have a direct impact on the health of the population. This work is devoted to the study of beta spectra of the natural radiation background in the surface atmospheric layer of the Earth. The origin of the measured beta spectra is associated with the daughter products of the decay of radon isotopes
219
Rn,
220
Rn, and
222
Rn in three natural radioactive series. Measurements of the spectra were performed from October 2018 to October 2019 in the foothills of the Zailiysky Alatau of the Tien Shan in Almaty. The frequency of measurements, on average, was about 10 measurements per day with an exposure of at least 2000 s. A database of daily, seasonal, and annual variations in beta spectra has been accumulated. For the analysis of the data obtained, a special software program Analyzer of the Beta Spectra Array was developed, which made it possible to process the standard output files of the Sputnik spectrometric installation and to integrate each spectrum in a given time interval. Time variation over the measured period was described using a standard mathematical computer package for wavelet analysis. The wavelet spectra obtained as a result of integration are used to identify daily, seasonal, and annual effects in variations of beta emanations. Along with this, similar mathematical processing was performed to predict the impact of external factors in the temporal variations of beta particles.
Iron oxide nanoparticles have been fabricated using the electric wire explosion (EWE) technique. The structure and magnetic properties of the nanoparticles have been analyzed before and after ...mechanical grinding in a ball mill for different time periods, focusing on potential bioapplications. The phase composition of the nanoparticles (70% Fe
3
O
4
, 30% Fe
2
O
3
) has remained unchanged despite the mechanical effects. The average nanoparticle size has not been affected either. The observation of the Verwey transition in the studied nanoparticles, along with the structural data, provides a better understanding of the physical properties of EWE ensembles of nanoparticles in different states. The analysis of the structure and magnetic properties reveals the development of a material with a high level of internal stress. This finding may be of interest for bioapplications due to its potential impact on the material performance.
A method to assess the gas resistance of woody plants was developed based on the level of inhibition of the photosynthetic activity of leaves exposed to toxic gases in the laboratory and could be ...used to identify plants resistant to environmental pollution for further practical and breeding use. The effective quantum yield of photosystem II was used as an indicator of genotype tolerance. The sensitivity of the indicator was sufficient to differentiate control and experimental variants. The objects under study were ranked according to the degree of gas resistance. Recommendations were given for the practical application of the new method.
Abstract
Measurements of the spatial distribution of radon isotopes were carried out from April 2021 to August 2021 in the foothills of the Trans-Ili Alatau of the Tien Shan in the Almaty region at ...various heights above sea level: from 500 to 2500 meters. They were carried out using electronic radiometric equipment: beta-dosimeter “RKS-01B-SOLO”; gamma dosimeter “RKS-01G-SOLO”; radiometer of radon and its daughter decay products “RAMON- 02” in the field. As a result, preliminary assessment schemes were built for route measurements of the
222
Rn radon isotope, beta and gamma radiation fields from natural daughter products of decay of radon isotopes and radionuclides located in the surface atmospheric layer.
A correlation between the parameter β
2
and a half-life
T
1/2
for oblate nuclei with sign β
2
< 0 and an anticorrelation for elongated nuclei sign β
2
> 0 are found. These analytical expressions for ...the function β
2
(
T
1/2
) make it possible to calculate the shape parameters of β
2
nuclei if we know the half-lives
T
1/2
for exotic nuclei for which this value is most accurately measured.
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