Modeling and Complex Analysis of the Topology Parameters of Ventilation Networks When Ensuring Fire Safety While Developing Coal and Gas Deposits

Underground mining, including underground coal mining, is accompanied by accidents and fire hazards that pose a threat to the life safety of miners. The fire hazard increases with an increase in the mining depth. Currently, most accidents in coal mines are mine fires. The cost of eliminating mine fires is 80–95% of the cost of eliminating all accidents occurring at mining enterprises. Therefore, the problem of developing a new methodology for modeling the ventilation network parameters of the mine to increase the reliability of controlling the aerogas mode at the excavation site is very relevant. The comprehensive analysis and assessment of gas-dynamic processes in coalmines under study were carried out using the methods of probability theory and mathematical statistics. Spatial data were processed using spline interpolation in “gnuplot”. As a result, a generalized expression for the transfer functions of coalmine objects, taking into account delays, was developed, including the description of dynamic properties of mining sites under various operating modes. The principal possibility of using a graphical method for estimating additional parameters of the sections of the ventilation system branches has been proved due to the alignment of their profiles at an equivalent distance relative to an arbitrary analogue. The improved method of spatial modeling was used to determine the gas-dynamic characteristics through additive gas-dynamic processes. The studies have been carried out and the method for managing the process of changing connections between devices (controllers–switches) of the technical system was developed in order to obtain greater reliability for safe mining. In subsequent studies, there is an issue of more detailed clarification of the peculiarities concerning the interrelations between the studied parameters in several projections of the response space

A tale of two stories: astrocyte regulation of synaptic depression and facilitation

Short-term presynaptic plasticity designates variations of the amplitude of synaptic information transfer whereby the amount of neurotransmitter released upon presynaptic stimulation changes over seconds as a function of the neuronal firing activity. While a consensus has emerged that changes of the synapse strength are crucial to neuronal computations, their modes of expression in vivo remain unclear. Recent experimental studies have reported that glial cells, particularly astrocytes in the hippocampus, are able to modulate short-term plasticity but the underlying mechanism is poorly understood. Here, we investigate the characteristics of short-term plasticity modulation by astrocytes using a biophysically realistic computational model. Mean-field analysis of the model unravels that astrocytes may mediate counterintuitive effects. Depending on the expressed presynaptic signaling pathways, astrocytes may globally inhibit or potentiate the synapse: the amount of released neurotransmitter in the presence of the astrocyte is transiently smaller or larger than in its absence. But this global effect usually coexists with the opposite local effect on paired pulses: with release-decreasing astrocytes most paired pulses become facilitated, while paired-pulse depression becomes prominent under release-increasing astrocytes. Moreover, we show that the frequency of astrocytic intracellular Ca2+ oscillations controls the effects of the astrocyte on short-term synaptic plasticity. Our model explains several experimental observations yet unsolved, and uncovers astrocytic gliotransmission as a possible transient switch between short-term paired-pulse depression and facilitation. This possibility has deep implications on the processing of neuronal spikes and resulting information transfer at synapses.Comment: 93 pages, manuscript+supplementary text, 10 main figures, 11 supplementary figures, 1 tabl

Sustainability of Inclusive Education in Schools and Higher Education: Teachers and Students with Special Educational Needs

One of the significant factors in the sustainability of education is the development of inclusive education. An inclusive educational space implies openness and accessibility of education for students, regardless of their educational needs. Inclusive education also means a partnership between students and teachers. A teacher is a living person whose socio-emotional skills and professional abilities are the basis for the sustainability of education and student development. This article is devoted to studying teachers’ competence and psychological readiness at schools and higher educational institutions to work with students with special educational needs. This article includes the results of a sociological study conducted in September 2022 and is devoted to the readiness of schoolteachers and university professors for inclusive education (N = 125). The general statistical calculation was carried out based on information processing using the Vortex program version 10.0. Universities and schools are located in large administrative centers of Russian regions with a population of about a million. The relevance of this study is due to the relationship of sustainability with the ideas of inclusive education, manifested in its goal of achieving students’ educational levels established by the state and the humanistic concept of equality of opportunity in the process of professional implementation and self-determination of the individual

Optical vortex propagation in few-mode rectangular polymer waveguides

We demonstrate that rectangular few-mode dielectric waveguides, fabricated with standard lithographic technique, can support on-chip propagation of optical vortices. We show that specific superpositions of waveguide eigenmodes form quasi-degenerate modes carrying light with high purity states of orbital angular momentum

Demonstration of optical vortex propagation in on-chip rectangular dielectric waveguides

Orbital angular momentum (OAM) of light provides an additional degree of freedom for multiplexing the data streams in optical communications, increasing further the channel capacity [1]. Applications of OAM for both classical data transmission [2] and quantum information [3] have been demonstrated. The key step towards robust, suitable for massive production, and cost-efficient OAM-assisted communications is the development of compact, on-chip integrable optical components. Summary form only given. Orbital angular momentum (OAM) of light provides an additional degree of freedom for multiplexing the data streams in optical communications, increasing further the channel capacity [1]. Applications of OAM for both classical data transmission [2] and quantum information [3] have been demonstrated. The key step towards robust, suitable for massive production, and cost-efficient OAM-assisted communications is the development of compact, on-chip integrable optical components.In this work we demonstrate propagation of vortex modes, carrying OAM, in rectangular dielectric waveguides, which can be produced with standard photolithography process. We show by numerical simulation that the specific superposition of waveguide eigenmodes form the quasi-degenerate modes carrying light with high purity states of OAM. Fig. 1(a-f) shows the amplitude and phase distributions of the dominant field component of quasi-TE vortex modes with topological charges ℓ = 1, 2 and 3, propagating in the few-mode waveguide with 10μmκ10μm PMMA core (n1 = 1.4794) and pure silica substrate (n2 = 1.444, n3 = 1). Numerical modelling has been performed using Matlab with full vector finite difference modesolver [4] for waveguide eigenmodes determination. We also demonstrate experimentally the propagation of the 1st order OAM mode in a polymer rectangular waveguide (4.5 μm × 4.1 μm core made of Ormosil with n1 = 1.50 at 1550 nm is deposited on silica substrate)

High-Power Quantum Cascade Lasers Emitting at 8 μm: Technology and Analysis

In this work, we demonstrate the features of a two-stage epitaxial growth technique and show the results of power and efficiency measurements for three different designs of quantum cascade lasers with a record-high peak power in the 8 μm spectral region. The time-resolved QCL spectral study proves that InP-based upper cladding paired with an InP contact layer provides better heat dissipation and allows one to reach better power characteristics in comparison with InGaAs-based contact, even with short pulse pumping