Technical Review of Robotic Complexes for Underground Mining

The paper contains classifies robots for work in mines, the tasks they perform, compares developments in this area with a description of the difficulties and solutions which have found. Social and economic difficulties that often hamper the process of automation and robotization of underground mining are given. © 2020 Published under licence by IOP Publishing Ltd

Diversity of Prokaryotes in Planktonic Communities of Saline Sol-Iletsk lakes (Orenburg Oblast, Russia)

© 2018, Pleiades Publishing, Ltd. Prokaryotic diversity was studied in the planktonic communities of six Sol-Iletsk lakes (Orenburg oblast, Russia) varying in salinity level using the Illumina technology of high-throughput sequencing. The extremely halophilic archaea of the phyla Euryarchaeota and Nanohaloarchaeota, as well as the bacterial phylum Bacteroidetes predominated in the communities of lakes with salinity of 285–300‰. Representatives of the phyla Bacteroidetes and Actinobacteria, as well as of the class Gammaproteobacteria were predominant in the lakes with salinity 110−180‰. A bloom of Cyanobacteria was observed in Bol’shoe Gorodskoe Lake (10‰ salinity). The dominant OTUs in the lakes with high salinity were represented by archaea Halonotius sp., uncultured Nanohaloarchaea, and bacteria Salinibacter sp. In the lakes with medium salinity level the dominants included gammaproteobacteria Spiribacter sp., alphaproteobacteria Roseovarius sp., flavobacteria Psychroflexus sp., unidentified archaea of the family Haloferacaceae, actinobacteria Pontimonas sp. and Rhodoluna sp. In the lake with low salinity level cyanobacteria of the genus Planktothrix were predominant. Effect of salinity on prokaryotic taxonomic richness, composition, and diversity in planktonic communities of the studied lakes was demonstrated

Computational and Experimental Evaluation of Heat Transfer Intensity in Channels of Complex Configuration for Gas Flow with Different Levels of Turbulence

Disclosure of the physical mechanism of the influence of the turbulence intensity of gas flows on the heat transfer level in pipes of different configurations is an urgent task in the field of heat and power engineering. A brief overview of the literature on this topic is given in the article. A description of the boundary conditions for modeling is presented. The main characteristics of the experimental stand and measuring instruments are described. The purpose of this study is to study the effect of the initial turbulence level of a stationary gas flow on the heat transfer intensity in long pipes with different cross sections. The study is carried out using numerical simulation. The simulation results are qualitatively confirmed using experimental data. The values of the local heat transfer coefficient are shown to increase from 5 to 17% with increasing turbulence intensity (from 2 to 10%) in pipes with different cross sections. The heat transfer intensity in a triangular pipe is found to increase up to 30% compared to a round pipe. It is revealed that there is an up to 15% suppression of heat transfer in a square pipe compared to a round pipe. The data obtained may be useful for the design of flow paths and gas exchange systems for power machines and installations. © 2021 Institute of Physics Publishing. All rights reserved

PHASE SHIFT INFLUENCE RESEARCH OF THE REFERENCE OSCILLATOR SIGNAL ON THE OUTPUT SIGNAL IN HOMODYNE DEMODULATION SCHEME

Subject of Research. Important feature of homodyne demodulation method based on the arctangent function approach is the phase shift between the reference oscillator signal and the interference signal. This phenomenon is caused by propagation delays of impulses in the optical interferometric sensor scheme and the analog low-pass filter in front of the phase modulator which produces the reference oscillator signal phase delay. There is multiplying of the reference oscillator signal and the interference signal in this homodyne demodulation scheme during its processing, and the phase shift between these signals leads to a distortion of the output signal. This paper deals with the findings of the phase shift influence of the reference oscillator signal by the output signal of the demodulation scheme at various parameters of the interference signal. Estimation of required accuracy is given of the phase shift compensation for the specified level distortion of the output signal. Method. Mathematical model is proposed in MATLAB. In this model, interference signal with changing parameters by a set of rules is passed through the considered demodulation scheme. This gives the possibility to obtain the dependences of the output signal amplitude from the reference oscillator signal phase shift, the operating point of the interferometer, the depth of phase modulation and amplitude of the measured phase signal. Results obtained during the simulation showed the need to compensate the reference oscillator signal phase shift. To assess this shift in the current homodyne demodulation scheme the original method of its determination has been proposed. The method is based on the transmission of the interference signal and the oscillator signal via one and the same band-pass filter that separates the phase modulation carrier frequency. According to the phase delay between the receiving signals, the value of the reference oscillator signal phase shift can be judged on. This shift can be corrected with knowledge of the value of the reference oscillator signal phase shift. Correction is achieved by making the required delay in reference oscillator signal. Main Results. The results of mathematical modeling show significant nonlinear dependences of the output signal on the reference oscillator signal phase shift at different values of the phase modulation depth, the operating point of the interferometer and the measured phase signal amplitude. It was found out that optimal values of the reference oscillator signal phase shift equal to 0, 180 and 360 provide minimum distortions of the output signal. It was shown that to achieve about 4% distortion level of the output signal phase shift compensation with an accuracy of 3% relative to period of the reference oscillator signal was required. Practical Significance. The original method making it possible to assess the value of the reference oscillator signal phase shift has been proposed. The reference oscillator signal phase shift compensation during considered homodyne demodulation scheme practical implementation provides the correctness of the scheme operation and increases the signal to noise ratio of the output signal

The first widespread solar energetic particle event of solar cycle 25 on 2020 November 29 : Shock wave properties and the wide distribution of solar energetic particles

Context. On 2020 November 29, an eruptive event occurred in an active region located behind the eastern solar limb as seen from Earth. The event consisted of an M4.4 class flare, a coronal mass ejection, an extreme ultraviolet (EUV) wave, and a white-light (WL) shock wave. The eruption gave rise to the first widespread solar energetic particle (SEP) event of solar cycle 25, which was observed at four widely separated heliospheric locations (similar to 230 degrees). Aims. Our aim is to better understand the source of this widespread SEP event, examine the role of the coronal shock wave in the wide distribution of SEPs, and investigate the shock wave properties at the field lines magnetically connected to the spacecraft. Methods. Using EUV and WL data, we reconstructed the global three-dimensional structure of the shock in the corona and computed its kinematics. We determined the magnetic field configurations in the corona and interplanetary space, inferred the magnetic connectivity of the spacecraft with the shock surface, and derived the evolution of the shock parameters at the connecting field lines. Results. Remote sensing observations show formation of the coronal shock wave occurring early during the eruption, and its rapid propagation to distant locations. The results of the shock wave modelling show multiple regions where a strong shock has formed and efficient particle acceleration is expected to take place. The pressure/shock wave is magnetically connected to all spacecraft locations before or during the estimated SEP release times. The release of the observed near-relativistic electrons occurs predominantly close to the time when the pressure/shock wave connects to the magnetic field lines or when the shock wave becomes supercritical, whereas the proton release is significantly delayed with respect to the time when the shock wave becomes supercritical, with the only exception being the proton release at the Parker Solar Probe. Conclusions. Our results suggest that the shock wave plays an important role in the spread of SEPs. Supercritical shock regions are connected to most of the spacecraft. The particle increase at Earth, which is barely connected to the wave, also suggests that the cross-field transport cannot be ignored. The release of energetic electrons seems to occur close to the time when the shock wave connects to, or becomes supercritical at, the field lines connecting to the spacecraft. Energetic protons are released with a time-delay relative to the time when the pressure/shock wave connects to the spacecraft locations. We attribute this delay to the time that it takes for the shock wave to accelerate protons efficiently.Peer reviewe

Origins of the Ambient Solar Wind: Implications for Space Weather

The Sun's outer atmosphere is heated to temperatures of millions of degrees, and solar plasma flows out into interplanetary space at supersonic speeds. This paper reviews our current understanding of these interrelated problems: coronal heating and the acceleration of the ambient solar wind. We also discuss where the community stands in its ability to forecast how variations in the solar wind (i.e., fast and slow wind streams) impact the Earth. Although the last few decades have seen significant progress in observations and modeling, we still do not have a complete understanding of the relevant physical processes, nor do we have a quantitatively precise census of which coronal structures contribute to specific types of solar wind. Fast streams are known to be connected to the central regions of large coronal holes. Slow streams, however, appear to come from a wide range of sources, including streamers, pseudostreamers, coronal loops, active regions, and coronal hole boundaries. Complicating our understanding even more is the fact that processes such as turbulence, stream-stream interactions, and Coulomb collisions can make it difficult to unambiguously map a parcel measured at 1 AU back down to its coronal source. We also review recent progress -- in theoretical modeling, observational data analysis, and forecasting techniques that sit at the interface between data and theory -- that gives us hope that the above problems are indeed solvable.Comment: Accepted for publication in Space Science Reviews. Special issue connected with a 2016 ISSI workshop on "The Scientific Foundations of Space Weather." 44 pages, 9 figure

Alterations of the extracellular matrix in ovarian cancer studied by Second Harmonic Generation imaging microscopy

<p>Abstract</p> <p>Background</p> <p>Remodeling of the extracellular matrix (ECM) has been implicated in ovarian cancer, and we hypothesize that these alterations may provide a better optical marker of early disease than currently available imaging/screening methods and that understanding their physical manifestations will provide insight into invasion.</p> <p>Methods</p> <p>For this investigation we use Second Harmonic Generation (SHG) imaging microcopy to study changes in the structure of the ovarian ECM in human normal and malignant ex vivo biopsies. This method directly visualizes the type I collagen in the ECM and provides quantitative metrics of the fibrillar assembly. To quantify these changes in collagen morphology we utilized an integrated approach combining 3D SHG imaging measurements and bulk optical parameter measurements in conjunction with Monte Carlo simulations of the experimental data to extract tissue structural properties.</p> <p>Results</p> <p>We find the SHG emission attributes (directionality and relative intensity) and bulk optical parameters, both of which are related to the tissue structure, are significantly different in the tumors in a manner that is consistent with the change in collagen assembly. The normal and malignant tissues have highly different collagen fiber assemblies, where collectively, our findings show that the malignant ovaries are characterized by lower cell density, denser collagen, as well as higher regularity at both the fibril and fiber levels. This further suggests that the assembly in cancer may be comprised of newly synthesized collagen as opposed to modification of existing collagen.</p> <p>Conclusions</p> <p>Due to the large structural changes in tissue assembly and the SHG sensitivity to these collagen alterations, quantitative discrimination is achieved using small patient data sets. Ultimately these measurements may be developed as intrinsic biomarkers for use in clinical applications.</p

Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR

Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal

Открытые вопросы удовлетворенности жизнью и профессионального выгорания в анестезиологии и реанимации

Abstract Anesthesiologists and resuscitators are at high risk of developing burnout, which can lead to various unfavorable consequences, such as suicide and/or medical errors. The aim of the study The dependence between happiness (satisfaction with life) and burnout in staff of anesthesiology and intensive care departments. Multicenter, anonymous, blind observational study.Materials and methods Maslach Burnout Inventory (MBI), Flourishing Scale (FS), Satisfaction with Life Scale (SWLS), the study also included a series of general questions (gender, age, specialization, subjective definition of “happiness”). The study included 361 participants, including 311 specialists from the departments of anesthesiology and intensive care, and a control group of 50 non-medical workers.Results According to the MBI, high burnout scores were registered for all three subscales: 15% of anesthetists, 17.5% of resuscitators, 9.9% of nursing staff, 0% in the control group. The high figures of some of the three subscales of burnout: 82% of anesthesiologists, 66.25% of resuscitators, 59.4% of nurses and nursing assistants, 14% in the control group. The life satisfaction level was significantly lower in all groups of health care staff in the study, compared to the control group. Only a little more than half of the medical workers (56.59%) never thought about suicide, which means that almost half of the staff of the anesthesiology and resuscitation departments thought to some extent about suicide.Conclusion There is a growing awareness of the problem of occupational stress and burnout in anesthesiology and resuscitation. The timely identification of the first symptoms of burnout, and the provision of anesthesiology-resuscitation staff with psychological tools/psychological support to deal with occupational stress and burnout are required today.Анестезиологи и реаниматологи находятся в группе высокого риска развития выгорания, которое может приводить к различным неблагоприятным последствиям, таким как суицид и/или медицинские ошибки.Цель исследования Изучение зависимости счастья (удовлетворенность жизнью) и эмоционального выгорания сотрудников отделений анестезиологии и реанимации.Материал и методы Мультицентровое анонимное слепое наблюдательное исследование. В ходе работы использован опросник Maslach Burnout Inventory (MBI) и шкалы Flourishing Scale (FS), Satisfaction with Life Scale (SWLS), в анализ также были включены ответы на серию общих вопросов (пол, возраст, специализация, субъективное определение понятия «счастье»). В исследование включен 361 участник, из них 311 специалистов отделений анестезиологии и интенсивной терапии, контрольная группа — 50 человек немедицинских работников.Результаты По данным MBI, высокие баллы эмоционального выгорания отмечены по всем трем субшкалам: 15% анестезиологов, 17,5% реаниматологов, 9,9% медсестер и младших медсестер, 0% в контрольной группе. Высокие показатели наблюдались по некоторым из трех субшкал выгорания: 82% анестезиологов, 66,25% реаниматологов, 59,4% медсестер и младших медсестер, 14% в контрольной группе. Уровень удовлетворенности жизнью оказался статистически значимо ниже у всех групп медицинских работников в исследовании по сравнению с контрольной группой. Только чуть больше половины медицинских работников (56,59%) никогда не задумывались о самоубийстве, а это значит, что почти половина сотрудников отделений анестезиологии и реанимации в той или иной степени задумывались о суициде.Заключение Растет осознание проблемы профессионального стресса и выгорания в анестезиологии-реаниматологии. Необходимым сегодня является своевременное выявление первых симптомов выгорания и предоставление сотрудникам анестезиологии-реанимации психологических инструментов/психологической поддержки для борьбы с профессиональным стрессом и выгоранием.

Structural Biology of Human H3K9 Methyltransferases

SET domain methyltransferases deposit methyl marks on specific histone tail lysine residues and play a major role in epigenetic regulation of gene transcription. We solved the structures of the catalytic domains of GLP, G9a, Suv39H2 and PRDM2, four of the eight known human H3K9 methyltransferases in their apo conformation or in complex with the methyl donating cofactor, and peptide substrates. We analyzed the structural determinants for methylation state specificity, and designed a G9a mutant able to tri-methylate H3K9. We show that the I-SET domain acts as a rigid docking platform, while induced-fit of the Post-SET domain is necessary to achieve a catalytically competent conformation. We also propose a model where long-range electrostatics bring enzyme and histone substrate together, while the presence of an arginine upstream of the target lysine is critical for binding and specificity. Enhanced version: This article can also be viewed as an enhanced version in which the text of the article is integrated with interactive 3D representations and animated transitions. Please note that a web plugin is required to access this enhanced functionality. Instructions for the installation and use of the web plugin are available i