The paper presents unique results of studying the composition of the ground ice (major components, trace elements, and rare earth elements — REEs) encountered at a depth of 200–250m in sedimentary ...and magmatic rocks in the Western Yakutia diamond-bearing regions. In addition to those established earlier, three new geochemical types of ground ice have been defined: (i) sulfate-hydrocarbonate, (ii) chloride-hydrocarbonate, and (iii) sulfate-chloride types with mixed cation composition. The ground ice geochemical features are caused by evolutionary processes of interaction in the water–rock system during permafrost formation. The enclosed rocks were the source for the addition of sulfate and chlorine ions, as well as trace elements, to the ground waters of the active water exchange zone that had existed before freezing. The distribution pattern of REEs in ground ice has a special form distinct from that of sedimentary rocks, kimberlites, and ocean waters, but similar to the REE pattern in local river waters. This REE pattern features the positive europium (Eu) anomaly and approximate equality of light and heavy REEs. The obtained results essentially expand the insight into ice-formation processes in sedimentary and magmatic rocks.
•Cement and intrusive ground ice is best developed in sedimentary and intrusive rocks.•Five geochemical types of texture-forming ground ice are distinguished.•We report unique signatures of ground ice, including trace elements and REEs.•The REE profile for ground ice features a Ʌ-shaped pattern with positive Eu anomaly.
Questions on the use of the radionuclide
68
Ga in the medical institutions of the Russian Federation for diagnosis of malignant tumors were examined. The task of precise measurement of
68
Ga activity ...in order to decrease dose loads for patients and enhance the effectiveness of the diagnosis is very important. Calibration of the mobile RIS-3A reference dose calculator to
68
Ga activity was studied. Various methods of calibration, ensuring traceability to the National Primary Standard of the units of radionuclide activity, the specific activity of radionuclides, and the stream of alpha and beta particles and photons of radionuclide sources in GET 6-2016 are: the method of direct comparison with a UÉA-7 installation from GET 6-2016, using a sample of
68
Ga solution; and the use of a gamma spectrometer and sources based on other radionuclides with traceability of the unit of radionuclides to GÉT 6-2016. The expanded uncertainty budgets of the calibration coefficient are presented for both calibration procedures, using the UÉA-7 installation from GET 6-2016, and a gamma spectrometer with
18
F. The convergence of the measurement results of
68
Ga activity on the reference dose calibrator, with calibration coefficients obtained by different methods, was evaluated. The results obtained confirm the applicability of the various calibration methods. The results of the study may find application in ensuring the traceability to GET 6-2016 of the units of activity of other promising radionuclides introduced into medical practice.
The results of ground-penetrating radar (GPR) studies of permafrost and aerial photography, carried out at key sites in the Sentsa River valley (Oka Plateau, Eastern Sayan Ridge), are presented.
For ...geophysical studies, an OKO-2 GPR completed with an AB-90 shielded antenna unit was used with a maximum sounding depth of up to 20 m and a resolution of 0.5 m. To account for the landscape elevation, the Trimble TS635 tacheometer and the Leiсa DISTO D 510 rangefinder performed hypsometric measurements with a step of 1.0 m. Aerial photography was carried out by a remotely piloted aircraft (RPA) DJI Inspire 1 Pro, equipped with a Zenmuse 3X camera (a resolution of 3840×2160 pixels) with a spatial resolution of 5.7–7.8 cm/pixel (in different years).
In the structure of frozen lacustrine-alluvial sediments, three GPR complexes are distinguished, corresponding to the active layer and frozen rocks with different amounts of schlieren, lenses and layers of texture-forming ice. The orthophoto map and tacheometric survey analysis showed that the destruction of frost mounds occurs from the second half of April to the first half of October. The most significant relief change is due to the thawing of icy pulverescent clayey silts. It leads to subsidence blocks in the ledge of the Sentsa River terrace. Lateral river thermoerosion also contributes to the frost mounds destruction.
The cytostatic effects of 5-fluorouracil, oxaliplatin, and 4-(5-methyl-5
H
-1,3dioxolo4,5-
f
-indol-7-yl)-3-(5-fluoro-1-benzofuran-3-yl)-1
H
-pyrrole-2,5-dione (9-ING-41), a new glycogen synthase ...kinase-3 inhibitor, were evaluated in 2D and 3D models of HT-29 colorectal adenocarcinoma cells. The HT-29 cells cultured in 3D were resistant to the test drugs, while in the case of the 2D model, not only cytostatic but also cytotoxic effect was observed. The highest cytotoxic effect was detected upon the addition of 9-ING-41, at high concentrations of which the cell viability decreased to 50% after 3 h of incubation. The results indicate that 3D cultures reproduce the tumor structure and drug resistance more accurately.
We studied the influence of nanoscale ZnO films deposited onto GaAs (001) on the process of GaAs epitaxial growth. We took into consideration the most important control parameters of molecular beam ...epitaxy, such as substrate temperature, As4/Ga effective flux ratio and growth rate and different thicknesses of ZnO films. We found that a ZnO film deposited on GaAs surface acts as a native GaAs oxide when the thickness of the film is being decreased, and can be removed thermally at a temperature of 620-630°C. We showed that it is possible to use nanoscale ZnO films with thickness ∼5 nm in order to create horizontal GaAs nanowires grown by a self-catalytic mechanism.
A thin current sheet (TCS), with the width of an order of thermal proton gyroradius, appears a fundamental physical object which plays an important role in structuring of major magnetospheric current ...systems (magnetotail, magnetodisk, etc.). The TCSs are nowadays under extensive study by means of space missions and theoretical models. We consider a simple model of the TCS separating two half‐spaces occupied by a homogenous magnetic field of opposite sign tangential to the TCS; a small normal component of the magnetic field is prescribed. An analytical solution for the electric current and plasma density in the close vicinity of the TCS has been obtained and compared with numerical simulation. The number density and the electric current profiles have two maxima each. The characteristic spatial scale zS of the maxima location was investigated as a function of initial pitch angle of an incoming charge particle. The effect of the thermal dispersion of the incoming proton beam have been taken into consideration.
Key Points
A new analytical solution is found
Analytical solution was compared with the numerical simulation
The new scaling is found
Bacterial inoculants of the commercially available plant growth promoting rhizobacteria (PGPR) Arthrobacter mysorens 7, Flavobacterium sp. L30, and Klebsiella mobilis CIAM 880 were selected to obtain ...ecologically safe barley crop production on cadmium (Cd) polluted soils. All the PGPR immobilized 24–68% soluble cadmium from soil suspension. A. mysorens 7 and K. mobilis CIAM 880 were highly resistant to Cd and grew in up to 1 and 3 mmol CdCl2 on DAS medium respectively. All PGPR were able to fix nitrogen (276–1014 nmol mg-1 bacterial DW) and to produce indole acetic acid (IAA) (126–330 nmol mg-1 bacterial DW) or ethylene (4.6–13.5 nmol bacterial DW). All the PGPR actively colonized barley root system and rhizosphere and significantly stimulated root elongation of barley seedlings (up to 25%), growing on soil containing 5 or 15 mg Cd kg-1 of soil. Created in the simulation mathematical model confirms our hypothesis that PGPR beneficial effect on barley growing under Cd-stress is a complex process. One of mechanisms underlying this effect might be increase of bacterial migration from rhizoplane to rhizosphere, where PGPR bind soluble free Cd ions in biologically unavailable complex forms. Among the studied PGPR K. mobilis CIAM 880 was the most effective inoculant. Inoculation with K. mobilis CIAM 880 of barley plants growing on Cd contaminated soil (5 mg Cd kg-1 of soil) under field conditions increased by 120% grain yield and 2-fold decreased Cd content in barley grain. The results suggest that the using K. mobilis CIAM 880 is an effective way to increase the plant yield on poor and polluted areas.
This paper presents study of microstructure of the material (tool steel 150Cr14) produced by the selective laser melting (SLM) technology. The chemical composition analysis and grain size ...measurements of the initial powder tool steel 150Cr14 were performed. The bulk density and flowability of the powder were investigated. Specimens were built under various building parameters such as laser scanning speed and laser power and tested on uniaxial tension. In this study, the effect of the SLM parameters on the mechanical properties of tool steel is investigated. Due to less surface quality limitations of SLM technology compared with conventional production techniques specimens were subjected to set of tests including measurement of surface roughness, inspection of inner structure which are influenced from building parameters.
Abstract
We analysed the balance of environmental, social and economic development of the regions of Asian Russia, assessing the level of adjusted net savings. Using the selected indicators and the ...assessment of natural, social and production capital values, the typology of territorial production and resource structures of the regions of Asian Russia has been created. Based on the
k
-means method, using ‘Statistica 12’ software, the clustering and structural zoning by the ratio of natural, productive and human capital in the regions of Asian Russia was carried out.
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