20 research outputs found
Concepts and criteria for assessing the technological independence and security of critical information infrastructure facilities
The article presents an analysis of the concepts and terms used in the Decree of the President of the Russian Federation No. 166 dated 30.03.2022 "On measures to ensure the technological independence and security of the critical information infrastructure of the Russian Federation". Differences in the concepts of technological sovereignty and security of infrastructure facilities are identified, as well as differences between the criteria for assessing the trust of software and hardware complexes and the criteria of Russian origin. Clarifications of the regulatory framework are proposed, which will eliminate discrepancies in concepts and contradictions in requirements
Ī“13C variation in carbonate platform sediments of the Northern Tethys in Late Jurassic
Š”arbon isotopic composition of Late Jurassic sediments displays a trend of 13 C depletion in the World ocean. Meanwhile, depending on local paleogeographical conditions, Ī“ 13 C curves for different palaeoprovinces differ in inclinations and absolute values (Nunn & Price 2010). That is why a separate Ī“ 13 C curve needs to be developed for every specific region. After such development, the inverse problem ā correlation of the sedimentary complex by comparing Ī“ 13 C parameters ā can be solved. A comparison of Ī“ 13 C values in contemporaneous sediments can be also used as an instrument for testing paleogeographical and paleoecological models. Previous Ī“ 13 C data for the Upper Jurassic sediments of the Tethys region were obtained for its Western passive margin and Central Atlantics (Padden et al. 2002, Coimbra et al. 2009). These data have been acquired from precisely dated hemipelagic sediments containing index fauna and epioceanic Ammonitico-Rosso facies. In the current study we present Ī“ 13 C variations in carbonate platform sediments from the backarc basin of the Northern Tethys (N20Ā° to N40Ā°) (Meijers et al. 2010) mostly based on Sr-chemostratigraphic correlation and dating of carbonate complexes. We studied Sr, C and O isotopic composition of the Upper Jurassic carbonate complexes of the Crimean Mountains. These complexes were formed under different conditions: Kimmeridgian and Early Tithonian sediments were deposited in shallow-water carbonate platform settings. In most cases they lack index fossils and their age is defined by Sr-chemostratigraphy (Rudko et al. 2014); Late Tithonian to Early Berriasian sediments were sampled from a carbonate platform reef facies, slope and toe of slope carbonate megabreccias. Reef and breccias deposits were dated using Sr-chemostratigraphy, and confirmed by calpionellide biostratigraphy. In the absence of well preserved faunal remnants in the studied sections, limestone samples with the best preservation of primary sedimentary textures were collected for Sr isotopicāgeochemical studies. Samples with large calcite veins or abundant epigenetic sparite were excluded from this research. Limestone samples for reconstructing the 87 Sr/ 86 Sr isotopic parameters of depositional environments were selected using geochemical criteria (Mn/Sr ā1.5ā°) and subjected to preliminary treatment in a 1 N ammonium acetate solution. From more then 100 analyzed samples only 13 best preserved were used to provide correlation between sections and the age of strata. Most of samples used to determine C isotopic composition are represented by micritic limestones with low content of sparry cements and fragments of primary aragonitic grains. The content of insoluble impurities in limestones does not exceed 9%. All selected samples display no correlation between the amount of siliciclastic impurities, Ī“ 13 C and Ī“ 18 Š values. Ī“ 13 C values in the measured samples vary between +1 and 3.5ā°, Ī“ 18 Š: from ā2.9ā° to +1,3ā°. C ā isotopic composition in 44 samples was considered to be diagenetically unaffected and they were selected to provide Ī“ 13 C curve. According to the results of comparison of stable isotope composition with microfacies of samples, Ī“ 13 C values are not environment-dependent in contrast to Ī“ 18 Š, which are slightly enriched in 18 O in offshore and slope facies. The measured values of Ī“ 13 Š” are falling from an average 3.2ā° in Late Kimmeridgian through 2.6ā° in Early Tithonian to 1.7ā° in Late Tithonian ā Early Berriasian. This corresponds to the global Ī“ 13 Š” trend in Upper Jurassic sediments (Nunn & Price 2010). Among other Kimmeridgian ā Berriasian carbonates the Northern Tethys carbonate platform deposits are 0.5ā1ā° higher than Ī“ 13 Š” from the Western Tethys (Coimbra et al. 2009). The following factors (or their combinations) may explain observed 13 C-enriched isotopic composition of the Northern Tethyan backarc basin deposits: 1. increased amount of shallow-water allochems and cements in the sediments of carbonate platform and its aprons, compared to hemipelagites of Western Tethyan margin; 2. increased bioproductivity of photosynthetic organisms ā cyanobacteria and green algae that played an important role in the studied Upper Jurassic carbonate platform deposits (Krajewski 2010, Piskunov et al. 2012, Bucur et al. 2014), removed large quantity of light carbon from water, leading to 13 C enrichment of bicarbonate. It is interesting to note that volcanic activity on Tethyan active margin seems not to have an impact on Ī“ 13 Š” values of the studied sediments
Co-variation of Mg and C isotopes in late Precambrian carbonates of the Siberian Platform: A new tool for tracing the change in weathering regime?
Glendonite-Like Carbonate Aggregates from the Lower Ordovician Koporye Formation (Russian Part of the Baltic Klint): Detailed Mineralogical and Geochemical Data and Paleogeographic Implications
Stellate and plate-like carbonate bodies, traditionally called anthraconites, are found throughout the Baltic-Ladoga Klint in bituminous shale of the Koporye Formation (Tremadocian, Lower Ordovician). Although this time interval is usually considered as a greenhouse, there is some evidence for the existence of at least temporary cold conditions during the Cambrian–Ordovician. However, the origin of anthraconites is still strongly debated. We studied the mineralogical, petrographic, cathodoluminescence, geochemical, and isotopic characteristics of anthraconites from five sections of the Russian part of the Baltic paleobasin. A close similarity between the morphological, petrographic, cathodoluminescence, and isotopic characteristics of the studied anthraconites with those of glendonites allow us to suggest that these bodies formed in a similar paleo-environment and should be considered as pseudomorphs of the mineral ikaite. The oxygen and carbon isotope ratios reveal that ikaite precipitation occurred in low-temperature conditions on the seafloor. The carbon isotopic values reveal influence of inorganic seawater carbon along with organic matter decomposition and/or methane oxidation during ikaite-glendonite transformations. The oxygen isotopic composition significantly changed after deposition due to meteoric diagenesis. We propose that the studied Tremadocian anthraconites formed under a region of upwelling, where cold phosphate-rich deep waters rose to the relatively shallow part of the Baltic paleobasin, providing favorable conditions for ikaite precipitation. Based on our cathodoluminescence study, we suggest that ikaite was transformed to calcite over several stages during diagenesis. Mineralogical studies also reveal that primary calcite was transformed to sulfate (gypsum) or dolomite during late superimposed processes
The ErosionāCorrosion Behavior of Eutectic High Chromium Cast Irons Reinforced by TiC Particles
In this work, high chromium cast irons (HCCIs) reinforced by TiC particles are designed and fabricated to improve the erosionācorrosion and wear resistances of materials for the pumping and handling applications. The TiC particles are formed by the in situ solidification method. The experimental results show that the hardness of as-cast HCCIs is improved significantly with TiC volume fraction. It can be as high as 63 HRC when the TiC volume fraction is 9.8%. The introduction of TiC increases the abrasive wear resistance of the HCCIs in both as-cast and heat-treated states. However, it is unexpected to find that the presence of TiC significantly reduces the erosionācorrosion performance. It suggests that corrosion-enhanced erosion is the dominant mechanism that controls the mass loss of the TiC-strengthened HCCIs
Revealing the dynamic behavior and micromechanisms of enhancing the formability of AA1060 sheets under high strain rate deformation
Developing high strain rate (HSR) forming technologies is significant for efficient and high-quality aerospace sheet metal parts manufacturing. Research on the deformation behaviors and micromechanism of materials under HSRs will contribute to the further application of HSR forming technologies. In this study, the mechanical behavior of AA1060 pure aluminum at low strain rates (LSRs, 0.001 sā1 and 0.1 sā1) and high strain rates (HSRs, 2400 sā1 and 3300 sā1) was tested utilizing quasistatic tensile tests and Hopkinson bar tests at room temperature. The results of the mechanical properties showed that the elongations were 30.01Ā %, 37.91Ā %, and 46.61Ā %, corresponding to strain rates of 0.1 sā1, 2400 sā1, and 3300 sā1, respectively, which were 29.86Ā % at a strain rate of 0.001 sā1. The maximum amplification of AA1060 elongation reached 56.10Ā % at the HSR. Microstructure characteristics, including the Schmid factor distribution, geometrically necessary dislocation (GND) distribution, slip band, and dislocation cell, were observed by electron backscattering diffraction (EBSD) and transmission electron microscopy (TEM) under the condition of the same elongation with strain rates of 0.001 sā1 and 3300 sā1. In addition, the reasons for the plastic improvements during HSR loading were also investigated. The hard-oriented grains participate in plastic deformation at HSRs, providing additional space for dislocation multiplication and movement, increased dislocation density, and interaction between dislocations. In addition, the deformed hard-oriented grains also coordinated the strain gradient with soft-oriented grains. This improved the overall deformation uniformity, thus avoiding the premature occurrence of strain localization, namely, the elongation increase
Gas Emissions From Volcanoes of the Kuril Island Arc (NW Pacific): Geochemistry and Fluxes
The Kuril Island arc extending for about 1,200 km from Kamchatka Peninsula to Hokkaido Island is a typical active subduction zone with ā¼40 historically active subaerial volcanoes, some of which are persistently degassing. Seven Kurilian volcanoes (Ebeko, Sinarka, Kuntomintar, Chirinkotan, Pallas, Berg, and Kudryavy) on six islands (Paramushir, Shiashkotan, Chirinkotan, Ketoy, Urup, and Iturup) emit into the atmosphereā>ā90% of the total fumarolic gas of the arc. During the field campaigns in 2015ā2017 direct sampling of fumaroles, MultiGas measurements of the fumarolic plumes and DOAS remote determinations of the SO2 flux were conducted on these volcanoes. Maximal temperatures of the fumaroles in 2015ā2016 were 510Ā°C (Ebeko), 440Ā°C (Sinarka), 260Ā°C (Kuntomintar), 720Ā°C (Pallas), and 820Ā°C (Kudryavy). The total SO2 flux (in metric tons per day) from fumarolic fields of the studied volcanoes was measured as ā¼1,800āĀ±ā300 t/d, and the CO2 flux is estimated as 1,250āĀ±ā400 t/d. Geochemical characteristics of the sampled gases include Ī“D and Ī“18O of fumarolic condensates, Ī“13C of CO2, Ī“34S of the total sulfur, ratios 3He/4He and 40Ar/36Ar, concentrations of the major gas species, and trace elements in the volcanic gas condensates. The mole ratios C/S are generally 7RA (where RA is the atmospheric 3He/4He). The highest 3He/4He ratios of 8.3RA were measured in fumaroles of the Pallas volcano (Ketoy Island) in the middle of the arc
A Novel Hydroforming Process by Combining Internal and External Pressures for High-Strength Steel Wheel Rims
As one of the key safety components in motor vehicles, the steel wheel rim is commonly fabricated with the roll forming process. However, due to the varied cross-sections of the rim and the low formability of high-strength steel, it is difficult to produce thin-wall and defect-free wheel rims to realize the purpose of light weight. To solve these problems, a novel hydroforming process by combining internal and external pressures (HIEP) was proposed to produce thin-wall wheel rims in the current study. The designed initial tube with diameter between the maximum and minimum diameter of the wheel rim ensures dispersed deformation and effectively avoids local excessive thinning. During HIEP, a hydroforming process was performed with two successive stages: the external pressure and internal pressure stages. Theoretical analysis and finite element method (FEM) were jointly used to investigate the effect of process parameters on the wrinkling and thinning. With the optimized parameters for internal and external pressure, the wrinkling of wheel rims is prevented under compressive state during the external pressure forming stage. Additionally, HIEP was experimentally carried out with high-strength steel rims of 650 MPa ultimate tensile strength (UTS). Finally, wheel rims with weight reduction of 13% were produced successfully, which shows a uniform thickness distribution with a local maximum thinning ratio of 11.4%
Learning Hygiene: Mortality Patterns by Religion in the Don Army Territory (Southern Russia), 1867ā1916
Novel potential causative genes in carotid paragangliomas
Abstract Background Carotid paragangliomas (CPGLs) are rare neuroendocrine tumors that arise from the paraganglion at the bifurcation of the carotid artery and are responsible for approximately 65% of all head and neck paragangliomas. CPGLs can occur sporadically or along with different hereditary tumor syndromes. Approximately 30 genes are known to be associated with CPGLs. However, the genetic basis behind the development of these tumors is not fully elucidated, and the molecular mechanisms underlying CPGL pathogenesis remain unclear. Methods Whole exome and transcriptome high-throughput sequencing of CPGLs was performed on an Illumina platform. Exome libraries were prepared using a Nextera Rapid Capture Exome Kit (Illumina) and were sequenced under 75 bp paired-end model. For cDNA library preparation, a TruSeq Stranded Total RNA Library Prep Kit with Ribo-Zero Gold (Illumina) was used; transcriptome sequencing was carried out with 100 bp paired-end read length. Obtained data wereĀ analyzed using xseqĀ which estimates the influence of mutations on gene expression profiles allowing to identify potential causative genes. Results We identified a total of 16 candidate genes (MYH15, CSP1, MYH3, PTGES3L, CSGALNACT2, NMD3, IFI44, GMCL1, LSP1, PPFIBP2, RBL2, MAGED1, CNIH3, STRA6, SLC6A13, and ATM) whose variants potentially influence their expression (cis-effect). The strongest cis-effect of loss-of-function variants was found in MYH15, CSP1, and MYH3, and several likely pathogenic variantsĀ in these genes associated with CPGLs were predicted. Conclusions Using the xseq probabilistic model, three novel potential causative genes, namely MYH15, CSP1, and MYH3, were identified in carotid paragangliomas