The change in the plant growth parameters is shown in model experiments by the example of various commercial high-yielding varieties of green peas (Sofia, Alfa, and Triumf) cultivated in sod-podzolic ...soil, when a toxic concentration of copper ions (165 mg/kg) and an ultradisperse humate-sapropel suspension (UDHSS) (0.005%–50 ppm) were introduced into the environment. The experiments were carried out two times in four repetitions for each variant under controlled conditions of intensive photoculture. It is shown that for all varieties, the introduction of the metal led to a decrease in the yield, by 57% for the varieties of Alfa and Sofia and by 45% for the Triumf variety. Moreover, in the latter, according to the ratio of inhibition of the biomass of the aboveground/underground organs, the root system turned out to be more stable to the toxicant effect. The average indices of root biomass reduction were only 29%, while for the other two varieties they were 52–62% of the control. When the substrate was contaminated, the Triumf variety differed in having values of copper accumulation in its biomass two times lower than the other two, which, in terms of the degree of tolerance, makes it rather a phytoexcluder for this metal. In addition, soil contamination with toxic copper led to an increase in the total chlorophyll content in the leaves of the Triumf peas by 15%, which is probably also associated with activation of the mechanism of nonspecific compensatory responses of the cultivar adaptation to stress. The introduction of the UDHSS into the medium neutralized the toxic effect of copper in all the above parameters towards the control.
The project Proryv Breakthrough now being implemented in our country is aimed at achieving a new quality of large-scale nuclear power, development, origination, and industrial implementation of a ...closed nuclear fuel cycle with thermal and fast reactors. Here the current status of the technologies for reprocessing spent nuclear fuel and recycling plutonium fuel is analyzed, and it is shown that the prerequisites for closing the nuclear fuel cycle in two-component nuclear energy in the mid-term from the mid-2030s are present.
Using the model of multipath propagation of radio waves and the method of unscented Kalman filtering, a nonlinear adaptive algorithm for tracking low-flying targets in a monopulse radar station has ...been developed. This algorithm, in contrast to the extended Kalman filter, makes it possible to compensate for significant autocorrelated interference in measurements of the elevation angle of low-flying targets, arising from reflections of radio waves from the underlying surface. The results of simulation of the proposed algorithm are presented.
In 139 patients with verified gastric cancer, the infiltration of the postoperative material with CD8
+
cells was analyzed. Automated morphometric analysis of immunostained slides was performed ...separately in different specimen sites (tumor center, invasive edge, and peritumoral mucosa). The mean area of infiltrating CD8
+
cells in the tumor center and in the invasive edge was not predictive, while in the peritumoral mucosa it provided a new negative predictive factor (hazard ratio 2.10; confidence interval 0.87-4.92, Cox regression) reliably associated with the TNM stage (hazard ratio 1.91; confidence interval 0.91-4.61, Cox regression).
The concept of plasma separation of spent nuclear fuel and radioactive waste is presented. An approach that is based on using an accelerating potential to overcome the energy and angular spread of ...plasma ions at the separation region inlet and utilizing a potential well to separate spatially the ions of different masses is proposed. It is demonstrated that such separation may be performed at distances of about 1 m with electrical potentials of about 1 kV and a magnetic field of about 1 kG. The estimates of energy consumption and performance of the plasma separation method are presented. These estimates illustrate its potential for technological application. The results of development and construction of an experimental setup for testing the method of plasma separation are presented.
The danger of the wastes from the reprocessing of spent nuclear fuel is largely determined by the presence in them of long-lived actinides, first of all, americium and curium. The solution to the ...problem could be to involve together with plutonium its attendant actinides in the fuel cycle of fast reactors. This article considers the technologies (reactor, fuel fabrication, and spent fuel reprocessing) that are necessary for burning actinides as part of mixed uranium-plutonium nitride fuel. It is shown that the concentration of actinides, produced in a fast reactor, in the fuel will not exceed 0.5% h.a. For the transmutation of actinides separated from VVER spent fuel simultaneously with plutonium, it is expedient to increase the americium proportion in the fuel to 1.2%. Consideration is given to the possibility of using carbothermal synthesis of the initial powders and tablet technology for the manufacture of mixed uranium-plutonium nitride fuel, as well as the combined technology of spent-fuel reprocessing, planned for realization at a pilot-demonstration power complex with the BREST-300 reactor, and their suitability for involving neptunium and americium in the fuel cycle along with plutonium and uranium.
Project Proryv (Breakthrough) is leading an effort to develop fast reactors with mixed uranium-plutonium nitride fuel as well as the installations and technologies of a closed nuclear fuel cycle ...(NFC) as a base for a new type of nuclear energy. The RTM-2 complex of computer programs, which performs combined modeling of the reactor core and NFC stages, was developed for performing complex investigation of NFC closure and optimizing the loads for the reactor installation. This article discusses the current state of the RTM-2 software complex and the development of an RTM-2-based virtual digital model for NFC closure in the context of the on-site power complex. In particular, it is within the purview of such a model to integrate with a verified and certified next-generation computational code EVKLID/V1 for modeling thermohydraulic processes in fast reactors as well as with the digital information model of the reactor core, which is a tool for processing and analyzing the controlled characteristics of the core and its components and fulfilling the nuclear and radiation safety requirements throughout the entire life cycle of the installation.
Synchrotron radiation incident on a block of multilayer X-ray mirrors of a two-mirror monochromator heats a silicon substrate, which leads to thermal deformation and an increase in the angular error ...of the surface shape. The work examines the heating of a block of multilayer X-ray mirrors by a synchrotron beam with a power of up to 200 W with an energy in the range of 8–36 keV at grazing angles of incidence in the range of 0.5°–1.3°. Using SolidWorks software, the silicon-substrate parameters for mirrors with grooves on the end surface are calculated at which the root-mean-square deviation of the angular error of the substrate’s surface shape is about 1 μrad for a grazing angle of 1.3°, and for smaller angles it is less than 1 μrad. Heat is removed from the substrate surface by water using copper radiators. Reducing the beam aperture at the monochromator output makes it possible to obtain rays reflected from the surface of mirrors, which has a standard deviation of the surface shape of an order of 0.5 μrad, while maintaining 88% of the initial beam power at a grazing angle of 1.3°. The use of a piezoelectric actuator to correct the substrate’s surface shape makes it possible to reduce the root-mean-square shape error to 0.1 μrad and 0.05 μrad at grazing angles of 0.9° and 0.5°, respectively.
Organo-inorganic hybrid materials based on inorganic oxyfluoride lead-borosilicate glass matrices and the metal-complex compound tris-(8-oxycholate) ytterbium (III) were obtained by the melt method. ...The spectral-luminescence properties of tris-(8-oxycholate) ytterbium and hybrid materials in the visible and IR ranges were studied under different excitations (377 and 785 nm). It is shown that the intensity of IR luminescence in the initial metal-complex luminophore surpasses the luminescence in the visible range and vice versa in the obtained hybrid materials — the intensity of visible luminescence significantly surpasses the IR-luminescence.
A brief description of the concept of a soft X-ray microscope for the Nanoscope station, which is planned to be installed at the SKIF fourth-generation synchrotron, is given. The microscope is ...designed to study the structure of cells and dynamic processes in them with nanometer spatial resolution. It will use a unique absorption contrast of ~15 between carbon-containing structures and water in the spectral range of the water window, λ = 2.3–4.3 nm, which eliminates the need for contrasting and the use of fluorophores and minimizes the doses of ionizing radiation absorbed in the samples to obtain high-quality 3D images. The scanning and projection schemes of the microscope, their main technical characteristics, including the calculated spectra and parameters of the undulator source are presented, and an estimate of the absorbed doses depending on the resolution is obtained. The main advantage of the proposed concept lies in the use of an objective lens of high-aperture multilayer X-ray mirrors, which makes it possible to clearly visualize the focal section of the sample. Technically simple axial tomography will also be used to reconstruct the three-dimensional structure of frozen or dried samples. In the scanning scheme, due to a low dose of radiation, it will be possible to study living plant cells with a resolution of up to 10 nm, animals with a resolution of up to 80 nm, and cryofixed samples with a resolution of up to 5 nm. In the projection scheme, due to simultaneous observation of the entire focal
XY
section, the time for obtaining three-dimensional images is significantly reduced, but due to a large dose, it will be oriented mainly on the study of fixed samples.
