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Development and implementation of monitoring of corrosion processes of hydrogen degasation in embrillation zones during the operation of gas pipeline
No full textPipelines for oil and gas create significant risks of destruction in the systems of industrial and main transportation of hydrocarbons in the presence of corrosion-embrittlement of metal. According to many researchers one of the main reasons for this process is in the area of hydrogen anomalies. It occurs under insulating coating. Insulating coating on the pipeline is peeled off from the metal in such places. Microcracks and pores appear; then moisture spreads to outer surface of the pipe and causes corrosion processes — embrittlement. In addition, it is not excluded that corrosion is intensified due to electrochemical processes and due to undercurrents of gaseous diffusion of hydrogen gas from the mantle strata formed in the areas of the pipeline location. Hydrogen is extremely permeable gas. It leads to swelling, insulation peeling off and defects expanding. The situation creates possibility for moisture penetration to the pipes surface. It also directly affects strength of the metal causing corrosion, cracking and embrittlement. Results of the studies show that embrittlement processes take place mostly in the areas where pipelines pass through oil and gas-bearing structures. In such places hydrogen exits are recorded.Funded by the Institute of Geological Sciences of the National Academy of Sciences of Ukraine. O. Shevchuk also funded by a grant from the Swedish Strategic Research Fund.</p
Taxonomic study of the subfamily Pyraustinae (Lepidoptera: Crambidae)in Iran
No full textSixty-seven species of the subfamily Pyraustinae from 17 genera and two tribes are listed. Anania verbascalis verbascalis ([Denis & Schiffermüller], 1949) is considered as a senior synonym of A. verbascalis parvalis (Osthelder, 1935) syn. n.; Pyrausta virginalis Duponchel, 1832 as a senior synonym of P. perkeo Amsel, 1970 syn. n.; and P. ferrealis (Hampson, 1900) as a senior synonym of P. euergestalis Amsel, 1954 syn. n. Thirteen species, namely Anania coronata (Hufnagel, 1767), A. murcialis (Ragonot, 1895), A. terrealis (Treitschke, 1829), Pyrausta ferrealis (Hampson, 1900), P. armeniaca Slamka, 2013, P. zeitunalis Caradja, 1916, P. cingulata (Linnaeus, 1758), P. delicatalis Caradja, 1916, P. tatarica Kemal et al., 2020, Loxostege sedakowialis (Eversmann, 1852), L. wagneri Zerny in Wagner, 1929, L. mucosalis (Herrich-Schäffer, 1848) and L. peltaloides (Rebel in Wagner, 1932), are newly reported from Iran. Additionally, a redescription of the male of P. delicatalis and the female of L. sedakowialis, as well as description of the hitherto unknown female of P. delicatalis are presented. The intraspecific variations of the species if present are discussed and additional new diagnostic characters to separate the closely related species are presented. Data on the geographical distribution of the Iranian species of this subfamily are provided
A crowd-sourced genomic project to assess hybrid content in a rare avian vagrant (Azure Tit Cyanistes cyanus (Pallas, 1770))
No full textHidden species diversity and mito-nuclear discordance within the Mediterranean cone snail, Lautoconus ventricosus
No full textThe Mediterranean cone snail, Lautoconus ventricosus, is currently considered a single species inhabiting the whole Mediterranean basin and the adjacent Atlantic coasts. Yet, no population genetic study has assessed its taxonomic status. Here, we collected 245 individuals from 75 localities throughout the Mediterranean Sea and used cox1 barcodes, complete mitochondrial genomes, and genome skims to test whether L. ventricosus represents a complex of cryptic species. The maximum likelihood phylogeny based on complete mitochondrial genomes recovered six main clades (hereby named blue, brown, green, orange, red, and violet) with sufficient sequence divergence to be considered putative species. On the other hand, phylogenomic analyses based on 437 nuclear genes only recovered four out of the six clades: blue and orange clades were thoroughly mixed and the brown one was not recovered. This mito-nuclear discordance revealed instances of incomplete lineage sorting and introgression, and may have caused important differences in the dating of main cladogenetic events. Species delimitation tests proposed the existence of at least three species: green, violet, and red + blue + orange (i.e., cyan). Green plus cyan (with sympatric distributions) and violet, had West and East Mediterranean distributions, respectively, mostly separated by the Siculo-Tunisian biogeographical barrier. Morphometric analyses of the shell using species hypotheses as factor and shell length as covariate showed that the discrimination power of the studied parameters was only 70.2%, reinforcing the cryptic nature of the uncovered species, and the importance of integrative taxonomic approaches considering morphology, ecology, biogeography, and mitochondrial and nuclear population genetic variation
The 3D biogeochemical marine mercury cycling model MERCY v2.0 – linking atmospheric Hg to methylmercury in fish
No full textMercury (Hg) is a pollutant of global concern. Due to anthropogenic emissions, the atmospheric and surface ocean Hg burden has increased substantially since preindustrial times. Hg emitted into the atmosphere gets transported on a global scale and ultimately reaches the oceans. There it is transformed into highly toxic methylmercury (MeHg) that effectively accumulates in the food web. The international community has recognized this serious threat to human health and in 2017 regulated Hg use and emissions under the UN Minamata Convention on Mercury. Currently, the first effectiveness evaluation of the Minamata Convention is being prepared, and, in addition to observations, models play a major role in understanding environmental Hg pathways and in predicting the impact of policy decisions and external drivers (e.g., climate, emission, and land-use change) on Hg pollution. Yet, the available model capabilities are mainly limited to atmospheric models covering the Hg cycle from emission to deposition. With the presented model MERCY v2.0 we want to contribute to the currently ongoing effort to improve our understanding of Hg and MeHg transport, transformation, and bioaccumulation in the marine environment with the ultimate goal of linking anthropogenic Hg releases to MeHg in seafood. Here, we present the equations and parameters implemented in the MERCY model and evaluate the model performance for two European shelf seas, the North and Baltic seas. With the model evaluation, we want to establish a set of general quality criteria that can be used for evaluation of marine Hg models. The evaluation is based on statistical criteria developed for the performance evaluation of atmospheric chemistry transport models. We show that the MERCY model can reproduce observed average concentrations of individual Hg species in water (normalized mean bias: HgT 17 %, Hg0 2 %, MeHg −28 %) in the two regions mentioned above. Moreover, it is able to reproduce the observed seasonality and spatial patterns. We find that the model error for HgT(aq) is mainly driven by the limitations of the physical model setup in the coastal zone and the availability of data on Hg loads in major rivers. In addition, the model error in calculating vertical mixing and stratification contributes to the total HgT model error. For the vertical transport we find that the widely used particle partitioning coefficient for organic matter of log(kd)=5.4 is too low for the coastal systems. For Hg0 the model performance is at a level where further model improvements will be difficult to achieve. For MeHg, our understanding of the processes controlling methylation and demethylation is still quite limited. While the model can reproduce average MeHg concentrations, this lack of understanding hampers our ability to reproduce the observed value range. Finally, we evaluate Hg and MeHg concentrations in biota and show that modeled values are within the range of observed levels of accumulation in phytoplankton, zooplankton, and fish. The model performance demonstrates the feasibility of developing marine Hg models with similar predictive capability to established atmospheric chemistry transport models. Our findings also highlight important knowledge gaps in the dynamics controlling methylation and bioaccumulation that, if closed, could lead to important improvements of the model performance
A multidisciplinary approach to resolving the end-Guadalupian extinction
No full textThe transition from the middle to late Permian (Guadalupian–Lopingian) is claimed to record one or more extinction events that rival the ‘Big Five’ in terms of depletion of biological diversity and reorganization of ecosystem structure. Yet many questions remain as to whether the events recorded in separate regions were synchronous, causally related, or were of a magnitude rivaling other major crises in Earth’s history. In this paper, we survey some major unresolved issues related to the Guadalupian–Lopingian transition and offer a multidisciplinary approach to advance understanding of this under-appreciated biotic crisis by utilizing records in Southern Hemisphere high-palaeolatitude settings. We focus on the Bowen-Gunnedah-Sydney Basin System (BGSBS) as a prime site for analyses of biotic and physical environmental change at high palaeolatitudes in the middle and terminal Capitanian. Preliminary data suggest the likely position of the mid-Capitanian event is recorded in regressive deposits at the base of the Tomago Coal Measures (northern Sydney Basin) and around the contact between the Broughton Formation and the disconformably overlying Pheasants Nest Formation (southern Sydney Basin). Initial data suggest that the end-Capitanian event roughly correlates to the transgressive “Kulnura Marine Tongue” in the middle of the Tomago Coal Measures (northern Sydney Basin) and strata bearing dispersed, ice-rafted gravel in the Erins Vale Formation (southern Sydney Basin). Preliminary observations suggest that few plant genera or species disappeared in the transition from the Guadalupian to Lopingian, and the latter interval saw an increase in floristic diversity
Prehistory of an enigmatic mineral: hisingerite
No full textAccording to most sources, the type locality for the hydrous iron silicate mineral hisingerite is Riddarhyttan, Västmanland, Sweden, first reported in 1828. However, it was described by A.F. Cronstedt as early as 1751 from Väster Silvberg, Dalarna (under the name “kolspeglande järnmalm”), and in 1810 by W. Hisinger from the Gillinge iron mine, Södermanland (“svart stenart”, later “gillingit”). J. Berzelius introduced the presently valid species name (originally spelt “hisingrit”) in 1819. Potential type materials are preserved by the Swedish Museum of Natural History, from Gillinge and Riddarhyttan. A Hisinger specimen from Gillinge has recently been analysed and was shown to contain associated potassic-hastingsite, magnetite and fayalite that explain the previously observed aluminium contents and high density for “gillingit”, compared to pure hisingerit
Gas dynamic phenomena (gdf) and causes of accidents at mines
No full textThere is a problem of development and implementation of prospecting technology to ensure protection of mining products and prevent disasters during the of coal deposits. It is especially relevant now when issue of environmental protection and improving labor safety in coal mines is very acute. Development of safe search technology for coal deposits is proposed by the authors. It will allow early monitoring to identify places of possible manifestations of gas-dynamic phenomena and make operational decisions for their elimination. The technology is based on application of exploratory gas-geochemical methods for mapping places of accumulation of gas-hydrogen accumulations and their areas. It together with a complex of geological-geophysical method allows to identify areas of possible emergency processes in development zones of mine fields. Feasibility of using search technology to justify use of laying anticipatory degassing wells to prevent uncontrolled explosive processes and technical disasters was proved on large array of conducted field work of planar and profile surveys. The proposed technology was tested on numerous mining sites in the process of exploratory and ecological research in development zones of active and exhausted mine fields.Funded by the Institute of Geological Sciences of the National Academy of Sciences of Ukraine. O. Shevchuk was additionally funded by a grant from the Swedish Strategic Research Fund.</p
