In Kazakhstan there are all conditions for the organization of the complete technological cycle of nuclear power generation, from extraction of uranium ores and ending with facilities for long-term storage of radioactive waste. In the Republic there have been no works yet on such an important component of this cycle as creation of underground RW disposal facilities, where the subject of separate investigation is an underground research laboratory (URL) for confirmation of the long-term safe disposal of RW in the selected location of the underground disposal facility. There for e during implementation of this project it is planned to use experience of the countries, where URL were designed, built and operated before creation of RW disposal sites. Such countries include Sweden, Finland, Japan, Russia, China, Belgium, India, Switzerland, etc., where there are extensive areas of crystalline rock development, and where deep RW disposal is recognized at the legislative level. The countries operating such facilities have proven technologies and experience in development, construction of URL and RW isolation sites.
Layered double hydroxides (LDHs) which are one type of layered material are promising materials due to some of their interesting properties, such as ease of synthesis, unique structure, uniform distribution of different metal cations in the brucite layer, surface hydroxyl groups, flexible tunability, intercalated anions with interlayer spaces, swelling properties, and high chemical and thermal stability, ability to intercalate different type of anions, and also high biocompatibility. This review article is focused on more information about synthesis methods of layered double hydroxides, and their applications in many fields. The most common synthesis methods for layered double hydroxides are co-precipitation, urea hydrolysis, hydrothermal synthesis, sol-gel, reconstruction, etc. are discussed. LDHs shows excellent performance as a multifunctional material for its promising applications in the fields of catalysts, water treatment, flame retardants, polymer additivies, adsorbents, nuclear industry, environmental protection, photocatalysts, and material science.
The article presents the monitoring data of medicinal substances (PM) in the surface waters of the city of Nur-Sultan and its environs (Republic of Kazakhstan). The results show the presence of carbamazepine and sulfamethaxazole in surface waters. Samples were taken monthly from April to December 2021. Analysis of medicinal substances was carried out using the method of high performance liquid chromatography (HPLC). A possible reason for the presence of medicinal substances in surface waters is their entry with wastewater from the public utility sector of the city of Nur-Sultan into surface sources after treatment.
Heterostructures based on graphene and two-dimensional films of nanostructured, ferromagnetic, transition metal oxides are promising for the development of new multifunctional materials for memory cells, quantum computer elements, Li-battery anodes, (photo) catalysts, supercapacitors, transistors, sensor materials, solar panels, fuel cells, electrochromic devices. A large volume of publications devoted to graphene and heterostructures based on it is and mainly their synthesis processes of hybrid structures. The methods of theoretical investigation of the optical properties of two-dimensional film materials, despite their diversity, require improvement. Consequently, the article presents methods of theoretical investigation of the optical properties of two-dimensional hybrid film structures in combination with ab-initio method.
The article presents findings on the content of radon isotopes in the air of buildings maintained in Kurchatov t., the dependence of concentrations of radon isotopes in residential and administrative buildings on a season assessed as well as on the type of premises and their purpose. Seasonal variations in radon concentrations in the air were studied by measuring the equivalent equilibrium volumetric activity (EEVA) and the volumetric activity (VA) of radon. For the first time, volumetric activities of radon isotopes in premises of residential and industrial buildings have been determined. Data showed that EEVA and VA values of radon in the air of residential and administrative premises surveyed increase from winter toward summer in the following descending series: summer > autumn > spring > winter, which, is perhaps related to soil freezing and the presence of the snow cover at the winter time. Radon concentration was also proved to decrease in the indoor air with a storey.
The paper presents the results of researching 137Cs radionuclide concentration in the organisms of mouse-like rodents (organisms of jerboa (Allactaga major Kerr and Allactaga saltator Eversmann) and marmots (Citellus erythrogenus Brandt)) living in the field of nuclear-weapon testing at the Semipalatinsk test site and the parameters of 137Cs radionuclide transition to organisms of studied animals. It is revealed that relatively elevated magnitudes of 137Cs activity concentration in organisms of jerboa and marmots are observed on the assumption of their residence in local contamination sites. With venturing from contamination sites at the distance exceeding the radius of animal activity, high values of radionuclides’ activity concentration are not reported. Despite the fact that animals live in the environment which components display high activity concentration of radionuclides, the extremely high concentration of radionuclide in these animals’ organisms has not identified.
The midpoint measures (AM±SD) of CRmuscl of 137Cs radionuclide for the muscle tissue of Allactaga saltator Eversmann amounted (2.1±1.3)×10−3 (n-11), for muscle tissue of Allactaga major Kerr – (4.7±2.7)×10−3 (n-9), for the muscle tissue of Citellus Erythrogenus Brandt – (7.0±5.6)×10−3 (n-6).
The article presents the results of studies to justify the project for decommissioning the IGR reactor facility. Based on the results of a comprehensive engineering and radiation survey, the IGR reactor system boundaries to be decommissioned were determined, and the compliance of the IGR reactor facility (IGR RF) state, its systems and equipment with the design requirements, executive and operational documentation was established. The neutronic calculations of the fission products’ activity and activation products, as well as the exposure dose rate of ionizing radiation at different distances from the main construction elements of the IGR RF, were performed using the MCNP5 software package. Based on the calculation results, a group of radionuclides was established, which makes the main contribution to the radioactive emission of the IGR reactor core, and the main construction elements that significantly affect the radiation environment of the IGR RF were determined. Based on the instrumental and computational studies results, the Terms of Reference for the development of the technical project “The IGR Reactor Facility Decommissioning” were developed and approved with the Committee of Atomic and Energy Supervision and Control of the Ministry of Energy of the Republic of Kazakhstan.
Due to their high surface area, electronic properties, energy storage performance and catalytic activity, two-dimensional (2D) nanostructures have attracted significant interest and great attention in developing science. Layered double hydroxides (LDHs) belong to 2D nanostructures and have a high surface area, very important physicochemical properties, and biological activity. However, there has always been great interest in their doping to enhance and improve these unique properties, especially photocatalytic activity. In this work, ZnAl-based LDHs were synthesized and their doping with active- (Ca, Sr), transition- (Co, Cu, Cd, Ni, Pb, Fe), noble- (Ag) and rare earth- (La) metals were carried out by impregnation method. The removal of cationic and anionic dyes from aqueous solutions by adsorption and photodegradation on as-synthesized and doped ZnAl-LDH/PVA nanocomposite was also studied. The obtained results were correlated with the structure and physicochemical properties of the nanocomposites.
This paper presents the travel times of P waves for 8 Yucca Flat (Nevada Test Site NTS) explosions from 1979 to 1984, with magnitudes mb = 4.9–5.9. Travel times were obtained by revising seismograms from the archives Sadovsky Institute of Geosphere Dynamics for the subsystem “Ozherel’e” (Necklace) of peripheral points Zerenda, Vostochniy, Chkalovo of the large-base seismic array system (SAS) of the geophysical observatory Borovoye. This system has been operating since 1979 on the territory of Kazakhstan. By the example of registration of underground nuclear explosions at the Yucca site of the Nevada Test Site (NTS), local travel time curves and linear trends in the P wave travel time in the range of epicentral distances 89.3110°–90.3701° are investigated. We estimate of the velocities of effective P waves for the Yucca-“Ozherel’e” and peripheral points.
The spectral characteristics of seismic and infrasound noise were calculated by the waveforms of the NNC RK network stations using PQLX software. The calculation results were compared with the seismic noise model by Peterson and infrasound noise by Brown. The daily and seasonal noise variations were analyzed. Special attention was paid to regularities of the level change at microseismic maximum. The observed peculiarities are well explained by the location and dynamics of microseism and microbarom sources located in the North Atlantics.
This article describes experimental investigations to determine the corrosion compatibility of candidate matrix materials of a capillary-porous structure (CPS) with a liquid tin-lithium alloy at high temperatures. The studies were conducted with the Sn75-Li25 alloy and samples of 12Ch18Ni10Ti grade austenite stainless steel, VEL-3 grade vanadium, and TT grade tantalum. Experiments on the interaction of a liquid tin-lithium alloy with candidate samples of the CPS matrix at high temperatures were carried out on an experimental TiGrA setup based on a TGA/DSC 3+ thermogravimetric analyzer. The paper provides a description of the methodology and conditions for conducting high-temperature corrosion tests. In the course of this work, experiments were carried out to study the compatibility of a tin-lithium alloy in the liquid phase with a stainless steel, vanadium and tantalum samples in the temperature range from 600 ℃ to 1000 ℃. Based on obtained results, the thermal effects of the processes occurring as a result of the interaction of the alloy with a candidate materials of the CPS matrix were determined. As a result of the analysis of the results obtained it has been revealed that at interaction of the studied materials with liquid tin-lithium alloy Sn75-Li25 at high temperatures complex physical and chemical processes take place, such as: selective dissolution of components by liquid alloy (solvent); penetration of component of liquid alloy (tin) into stainless steel depth; mass transfer of dissolved metals from solid metal into liquid.
In this study, we report a novel composite based on a porous 3D cryogel and Ti3C2Tx Mxene nanosheets, as well as Ag nanoparticles (MXene/Ag/Cryogel), which was obtained by self-assembly and applied to the removal of methylene blue (MB) with synergism of adsorption and photocatalytic degradation. The synergistic effect for the resulting composites with respect to MC removal is associated with the excellent adsorption capacity of the cryogel and the photocatalytic activity of MXene/Ag. The studies performed have shown that MXenes improve not only the adsorption process due to the presence of numerous functional groups, but also the photocatalytic decomposition of SM due to their high electrical conductivity. In addition, the incorporation of Ag NP improves the ability to absorb light that excites the surface electrons of Ag NP through the effect of surface plasmon resonance. In general, the results obtained indicate that the synergistic effect of adsorption-photocatalysis is an effective way to remove organic pollutants.
ISSN 1729-7885 (Online)
