30 research outputs found
Osteosynthesis of small fragments in multicomminuted fractures of the distal humerus metaepiphysis
The purpose of this study was to improve the treatment results of multicomminued fractures of the distal humerus metaepiphysis through the development
of a compression device that provides stable osteosynthesis of small fragments. Materials and methods Clinical testing of the device developed for
osteosynthesis of small fragments in multicomminuted fractures of the distal humerus metaepiphysis (patent of Ukraine for useful model #12560) was
conducted. Treatment sample included 104 persons with multicomminued fractures of the distal humerus metaepiphysis admitted to the Donetsk national
medical university and national trauma center of Donetsk. Results Osteosynthesis of small fragments in multicomminuted metaepiphyseal fractures of the
distal humerus with the help of the developed by us compression device enabled to reduce and stabilize small bone fragments, provided the possibility
of early movements in the joint and resulted in good outcomes. Conclusions Osteosynthesis of small fragments with application of the developed by
us compression device in patients with multicomminued fractures of the distal humerus metaepiphysis showed high efficiency. The mean score was
82.67 ± 5.59 points, which corresponds to good results of treatment
Ocean-bottom seismographs based on broadband MET sensors: architecture and deployment case study in the Arctic
The Arctic seas are now of particular interest due to their prospects in terms of hydrocarbon extraction, development of marine transport routes, etc. Thus, various geohazards, including those related to seismicity, require detailed studies, especially by instrumental methods. This paper is devoted to the ocean-bottom seismographs (OBS) based on broadband molecular–electronic transfer (MET) sensors and a deployment case study in the Laptev Sea. The purpose of the study is to introduce the architecture of several modifications of OBS and to demonstrate their applicability in solving different tasks in the framework of seismic hazard assessment for the Arctic seas. To do this, we used the first results of several pilot deployments of the OBS developed by Shirshov Institute of Oceanology of the Russian Academy of Sciences (IO RAS) and IP Ilyinskiy A.D. in the Laptev Sea that took place in 2018–2020. We highlighted various seismological applications of OBS based on broadband MET sensors CME-4311 (60 s) and CME-4111 (120 s), including the analysis of ambient seismic noise, registering the signals of large remote earthquakes and weak local microearthquakes, and the instrumental approach of the site response assessment. The main characteristics of the broadband MET sensors and OBS architectures turned out to be suitable for obtaining high-quality OBS records under the Arctic conditions to solve seismological problems. In addition, the obtained case study results showed the prospects in a broader context, such as the possible influence of the seismotectonic factor on the bottom-up thawing of subsea permafrost and massive methane release, probably from decaying hydrates and deep geological sources. The described OBS will be actively used in further Arctic expeditions
Pure Gauge Configurations and Tachyon Solutions to String Field Theories Equations of Motion
In constructions of analytical solutions to open string field theories pure
gauge configurations parameterized by wedge states play an essential role.
These pure gauge configurations are constructed as perturbation expansions and
to guaranty that these configurations are asymptotical solutions to equations
of motions one needs to study convergence of the perturbation expansions. We
demonstrate that for the large parameter of the perturbation expansion these
pure gauge truncated configurations give divergent contributions to the
equation of motion on the subspace of the wedge states. We perform this
demonstration numerically for the pure gauge configurations related to tachyon
solutions for the bosonic and the NS fermionic SFT. By the numerical
calculations we also show that the perturbation expansions are cured by adding
extra terms. These terms are nothing but the terms necessary to make valued the
Sen conjectures.Comment: 30 pages, 9 figures, references added and conclusion extende
Martian dust storm impact on atmospheric H<sub>2</sub>O and D/H observed by ExoMars Trace Gas Orbiter
Global dust storms on Mars are rare but can affect the Martian atmosphere for several months. They can cause changes in atmospheric dynamics and inflation of the atmosphere, primarily owing to solar heating of the dust. In turn, changes in atmospheric dynamics can affect the distribution of atmospheric water vapour, with potential implications for the atmospheric photochemistry and climate on Mars. Recent observations of the water vapour abundance in the Martian atmosphere during dust storm conditions revealed a high-altitude increase in atmospheric water vapour that was more pronounced at high northern latitudes, as well as a decrease in the water column at low latitudes. Here we present concurrent, high-resolution measurements of dust, water and semiheavy water (HDO) at the onset of a global dust storm, obtained by the NOMAD and ACS instruments onboard the ExoMars Trace Gas Orbiter. We report the vertical distribution of the HDO/H O ratio (D/H) from the planetary boundary layer up to an altitude of 80 kilometres. Our findings suggest that before the onset of the dust storm, HDO abundances were reduced to levels below detectability at altitudes above 40 kilometres. This decrease in HDO coincided with the presence of water-ice clouds. During the storm, an increase in the abundance of H2O and HDO was observed at altitudes between 40 and 80 kilometres. We propose that these increased abundances may be the result of warmer temperatures during the dust storm causing stronger atmospheric circulation and preventing ice cloud formation, which may confine water vapour to lower altitudes through gravitational fall and subsequent sublimation of ice crystals. The observed changes in H2O and HDO abundance occurred within a few days during the development of the dust storm, suggesting a fast impact of dust storms on the Martian atmosphere
No detection of methane on Mars from early ExoMars Trace Gas Orbiter observations
The detection of methane on Mars has been interpreted as indicating that geochemical or biotic activities could persist on Mars today. A number of different measurements of methane show evidence of transient, locally elevated methane concentrations and seasonal variations in background methane concentrations. These measurements, however, are difficult to reconcile with our current understanding of the chemistry and physics of the Martian atmosphere, which-given methane's lifetime of several centuries-predicts an even, well mixed distribution of methane. Here we report highly sensitive measurements of the atmosphere of Mars in an attempt to detect methane, using the ACS and NOMAD instruments onboard the ESA-Roscosmos ExoMars Trace Gas Orbiter from April to August 2018. We did not detect any methane over a range of latitudes in both hemispheres, obtaining an upper limit for methane of about 0.05 parts per billion by volume, which is 10 to 100 times lower than previously reported positive detections. We suggest that reconciliation between the present findings and the background methane concentrations found in the Gale crater would require an unknown process that can rapidly remove or sequester methane from the lower atmosphere before it spreads globally
Molecular dynamics simulations of the Nip7 proteins from the marine deep- and shallow-water Pyrococcus species
Enchytraeidae (Annelida: Oligochaeta) from the North-Western Caucasus, Russia, with the Description of <i>Fridericia gongalskyi</i> sp. nov.
The first list of terrestrial enchytraeids of the north-western Caucasus includes 24 species belonging to seven genera. A new enchytraeid species of the genus Fridericia, Fridericia gongalskyi sp. nov., is described. It clearly differs from other species of the genus by the presence of only three pairs of preclitellar nephridia, the postclitellar position of the chylus cells and two elongated spermathecal diverticula. The phylogenetic relations of the new species within the genus are discussed
Layered Oxygen-Deficient Double Perovskites as Promising Cathode Materials for Solid Oxide Fuel Cells
Development of new functional materials with improved characteristics for solid oxide fuel cells (SOFCs) and solid oxide electrolysis cells (SOECs) is one of the most important tasks of modern materials science. High electrocatalytic activity in oxygen reduction reactions (ORR), chemical and thermomechanical compatibility with solid electrolytes, as well as stability at elevated temperatures are the most important requirements for cathode materials utilized in SOFCs. Layered oxygen-deficient double perovskites possess the complex of the above-mentioned properties, being one of the most promising cathode materials operating at intermediate temperatures. The present review summarizes the data available in the literature concerning crystal structure, thermal, electrotransport-related, and other functional properties (including electrochemical performance in ORR) of these materials. The main emphasis is placed on the state-of-art approaches to improving the functional characteristics of these complex oxides