Analysis of microstrip structures by numerical conformal transformations technique

Computer aided microstrip structures modeling has been performed by conformal mapping technique. A new approach to reduce the connectivity order of the original cross-section geometry of the structure is proposed. The multiply connected domain is reduced to simply connected ones by implementation of magnetic slits concept. The microstrip structures analysis is carried out by numerical conformal transformations technique realized in Schwarz–Christoffel toolbox for MATLAB. This technique is applied to the quasi-static analysis of coupled microstrip lines taking into account the conductor thickness. Described approach ensures high numerical efficiency and can be used for accurate analysis of complex microstrip structures

A reliability study of the traction drive system in haul trucks based on failure analysis of their functional parts

The efficiency of a mining and processing plant depends on the level of complex mechanization of the production process. In mineral extraction, haulage is a major cost category, with haul trucks being the key component of the mining transportation system. To improve production performance, mining operations can increase their haulage turnover and reduce transportation costs, which necessitates making haul trucks more reliable. This can be done by improving their mean time to first failure (MTFF) indicators. This article analyzes the reliability status of the traction drive system inhaul trucks operating in the mineral resources sector. It provides a quantitative assessment of traction drive system failures resulting from part defects and discusses the associated repair costs. By examining failure data from 2018 to 2022 and the results of vibration tests performed on a diesel generator, the study reveals that the most expensive failures are associated with defects in the synchronous generator, which are primarily caused by elevated external vibrations. Based on basic vibration tests and vibration spectra tests at different operating modes, recommendations have been formulated concerning the generator’s robustness to external mechanical forces and the ways to increase the generator’s protection grade to prevent dust intrusion. The study also identifies the frequency range that poses the greatest risk of damage to the windings

HYPERNEURONS. SPECTRAL SYNTHESIS OF NEUROSTRUCTURE MODULES

In the synthesis of the hyperneuron module, lies the mathematical idea of a tangent bundle in the space of a logical function definition. The base of the tangent bundle and the input affine transformations of the neuron are determined on the basis of Walsh spectral representations. The example of synthesis for a randomly given logical function of 6 variables is presented

BINOMIAL HYPERFILTERS. THE APPLICATION OF THE SPECTRAL METHOD IN THE NEURAL STRUCTURES

The given paper describes the design and the method of hyperlinear filter’s synthesis. On its basis the scheme of the binomial filter is offered that will provide the increase in the efficiency of the neural structures. Methods of calculations using the spectral representations of Walsh are given. The estimates of the synthesized structures efficiency are indicated

SPECTRAL METHOD OF ARTIFICIAL BIPOLAR NEURON SYNTHESIS

The structure of an artificial bipolar neuron with local linear filters at the inputs is proposed. A spectral algorithm for the synthesis of the structure is described. An example of synthesis for a randomly assigned logical function is demonstrated. The effectiveness of the application of the structure is estimated

EFFECTIVE ELEMENTAL BASE OF SWITCHING NEUROSTRUCTURES

Designs of logical elements and artificial neurons are described, which are simple in technical and software implementation. Walsh spectral representations are widely used

Preparation and Characterization of di- and Tricarboxylic Acids-Modified Arabinogalactan Plasticized Composite Films

To ensure the high quality of water, it is necessary to remove toxic pollutants. At present, purification of water is implemented using various sorbents. The efficient sorption materials are modified polysaccharides. In this study, we report on a new environmentally friendly method for modifying larch hemicellulose—arabinogalactan (AG)—with polybasic carboxylic acids (citric, succinic, oxalic, and adipic) to obtain composite materials. The synthesized AG derivatives have been explored by a complex of physicochemical methods, including gel permeation chromatography (GPC), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffractometry (XRD), scanning electron microscopy (SEM), and sorption capacity investigations. It is shown that the heat treatment results in the formation of additional inter- and intramolecular bonds between carboxylic acids and polysaccharide molecules. The formation of ester bonds has been confirmed by the appearance of absorption bands in the IR spectra in the range of 1750–1690 cm−1. It has been found, using the TGA study, that the most thermally stable (up to 190 °C) sample is arabinogalactan oxalate obtained under heat treatment. The SEM study of the synthesized AG films has shown that the modified samples have the homogeneous film surface ensured by cross-linking. It has been established, when studying the sorption properties of the AG derivatives, that AG succinate (82.52%) obtained by lyophilization has the highest sorption capacity, due to the developed mesoporous surface, which, in turn, makes the synthesized films promising eco-friendly materials for use as drug carriers, sorbents, and water treatment agents

Factors of early protective action of live influenza vaccine combined with recombinant bacterial polypeptides against homologous and heterologous influenza infection

We are developing an associated vaccine based on live influenza vaccine (LAIV) and streptococcal recombinant peptides. The recombinant group B streptococcus (GBS) peptides P6 and ScaAB demonstrated a distinguished immunomodulating effect in THP-1 cells. The increase in IFN 1-alpha expression after ScaAB inoculation was similar to that against LAIV. We immunized mice intranasal using of A/H7N3 LAIV or/and ScaAB peptide. At day 5 after immunization, we detected serum IgM which reacted with non-vaccine influenza viruses. Associated vaccination of mice using LAIV and GBS peptide was the most effective against sub-lethal infection with A/H7N9 influenza virus and against lethal challenge with A/H1N1pdm virus at day 5 after immunization. Not only LAIV but also the ScaAB protected about 20% of the immunized animals against lethal challenge with A/H1N1pdm virus. The early protection was related to increasing type 1 interferons expression in the lungs.Our results in mice have shown that successful protection against homologous and heterologous influenza infections can be achieved soon after vaccination with either LAIV or LAIV in combination with GBS recombinant peptide. Presumably, such protection may be mediated by non-specific IgM antibodies and an increase in the expression of early cytokines in the airway

Computed Tomography-Assisted Study of the Liquid Contrast Agent’s Spread in a Hydrogel Phantom of the Brain Tissue

Studying transport processes in the brain’s extracellular space is a complicated problem when considering the brain’s tissue. Tests of corresponding physical and mathematical problems, as well as the need for materials with cheap but realistic properties to allow for testing of drug delivery systems, lead to the development of artificial phantom media, one kind of which is explored in this work. We report results from quantifying the spread of a standard contrast agent used in clinical computed tomography, Iopromide, in samples of collagen-based hydrogels. Its pure variant as well as samples supplied with lipid and surfactant additives were explored. By comparing to solutions of the diffusion equation which reproduce these data, the respective diffusion coefficients were determined. It was shown that they are relevant to the range typical for living tissue, grow with elevation in the lipid content and diminish with growth in surfactant concentration