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The aim of this work is to develop a thermoemission cathode that would ensure the required operating parameters and remain operable after long, several-day, exposure to the air without any additional ampulization. Cathode thrmoemitter degradation (“poisoning”) processes are overviewed. The problem of degradation of tungsten-barium cathodes is caused by the penetration of chemically active substances (for example, oxygen) into the interior space of a cathode. The “poisoning” process is so complex that it can hardly be simulated by simple theoretical methods. Because of this, the cathode “poisoning” degree under exposure to the atmosphere is usually assessed using experimental data. The analysis of publications on the resistance of cathode emitters to atmospheric exposure showed that one of the most promising solutions to the cathode “poisoning’ problem is the use of an emitter based on barium scandate. A cathode construction diagram was chosen, and a laboratory prototype cathode was made. The current dependence of the discharge voltage at different xenon flow rates and the xenon flow rate dependence of the discharge voltage at different currents were studied experimentally (xenon was the plasma-forming gas). During the trests, the cathode was periodically removed from the vacuuum chamber to inspect it for further use, the maximum duration of continuous exposure to the air was 14 days, and the resets did not reveal any significant change in the performance. The use of barium scandate as an emission-active substance for the thermoemission cathode improved its resistance to atmospheric exposure. The practical use of the cathode developed in experimental studies, for example, in the vacuum chamber of the plasmaelectrodynamic setup of the Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, will eliminate frequent cathode replacements, thus significantly speeding up research activities.

Arbuscular mycorrhiza (AM) is one of the most common terrestrial plant-microbe symbioses. The interest in studying AM is caused by its importance for the growth and nutrition of plants and its ecological role in preserving biological diversity. At present, 92% of plant families are known to form AM. Fungi in AM are obligate symbionts and belong to a monophyletic group – Glomeromycotina subdivision. Some researchers believe that formation of AM-symbiosis with fungi by ancient plants allowed them to inhabit land, which has led to the formation of the biosphere as we know it. AM is studied by researchers from around the world including Russia. This overview presents in brief the results of AM research in Russia during the Soviet period which did not receive international coverage due to its classified nature; the most prominent research schools and works of AM researchers are identified; main stages and lines of this research are listed, such as: distribution of AM in plant communities and different climatic zones, mycorrhiza anatomy and morphology, fungi species composition on different soils, collection of AM fungi and growing AM in vitro, physiological role of AM for agricultural plants, the impact different ecological factors have on AM fungi species composition and AM development, conditions for effective use of Am fungi to increase productivity and quality of agricultural plants as well as to perform biological recultivation of toxic soils and restore the fertility of degraded soils.

Economic convergence and digitalization are the most important trends of the modern community development. It is their interaction that creates new opportunities for the improvement of competitive capability and performance in the framework of joint business conducted by representatives of the wide variety of segments and sectors of economy. In response to digitalization, an ecosystem becomes the main institutional and organizational form of business in the framework of inter-sectoral economic convergence. The purpose of this article is to define more exactly the concept of an ecosystem as a form of doing joint business in the environment of inter-sectoral economic convergence and digitalization, and to build a classification of ecosystems. The following hypothesis is put forward in the study: an ecosystem as an institutional and organizational form of doing joint business is the result of the concurrent impact of inter-sectoral economic convergence and digitalization thereon, and the "connection of the base product provided to customer by the inter-sectoral economic convergence initiator prior to creating an ecosystem with digital and/or information technology" may be a criterion for classification of economic ecosystems. The novelty of the approach is as follows. The consideration of an ecosystem as a form of doing joint business simultaneously influenced by economic inter- sectoral convergence and digitalization has made it possible to define more exactly the concept of an ecosystem, identify an ecosystem parameter to be applied for classification of ecosystems and the main characteristic thereof the values of which may be used to classify economic ecosystems.

The article discusses a method to increase the efficiency of evolutionary genetic search in coding of modular network structures. A method for unfolding a genotype to form a phenotype using production rules generated by applying formal apparatus of L-systems and repair mechanisms is proposed. Forward and reverse coding techniques are considered. The method provides a combination of compactness of genetic code representation and advanced capabilities to increase dimension of resulting networks.

Conversion of waste heat into usable electricity is a strategic technology for saving natural resources and an important option for powering autonomous devices. Current developments in micro- and n...

A method for digital signal processing in SDR receivers with analog conversion to a low intermediate frequency is proposed. In contrast to known systems, the proposed approach does not consider parasitic phase and amplitude distortions, but uses the direct method minimizing of the signal of the mirror reception channel. Generally speaking, this can be done simultaneously at several frequencies. It is shown that in computational terms, this is reduced to signal processing by an algorithm similar to a digital non-recursive filter, and to determine its coefficients, it is sufficient to solve a system of linear algebraic equations.

The article discusses a number of problems manifested during the sudden forced transition of educational institutions to the use \pagebreak of exclusively distance learning technologies in the context of the COVID-19 pandemic, and the specifics of these problems for the areas of higher education related to the use of information technologies. A feature of these fields is the preparedness of teachers and students to use modern information technologies, as well as the high motivation of students. Under the conditions of force majeure, when the necessary stage of designing distance learning and filling it with content was forcibly skipped, both general and specific problems in organizing the educational process arose. The article analyzes the results of surveys of teachers and students conducted by the authors, which made it possible to list these problems and identify their economic and organizational reasons.

A universal technology for obtaining virus-containing raw material used in the manufacture of vaccine preparations against plague in small ruminants, sheep pox, goat pox, bluetongue disease, and orf (contagious pustular dermatitis) of cattle has been described. The epizootic situation in the Russian Federation and neighboring countries in respect to these diseases, which pose the greatest danger for the introduction of a virus from their territory, has been analyzed. The main technological parameters used in the production of highly active viral raw material required for the manufacture of vaccine preparations are presented. It has been shown that, in the obtained transplantable sublines of cell cultures of sheep kidney and saiga kidney, which are interchangeable, it is possible in one production cycle to obtain 48 dm3 of vaccinated material with an activity of 5.58–6.67 log TCD50/cm3, from which one can produce from 4.5 to 9.0 million doses of vaccine. When using vaccines prepared on the basis of the described technology, the animals developed intense immunity to the indicated diseases.

The effect of a set of quasi-neutral regimes of carrier transport in semiconductors, including, along with diffusion and drift, recently discovered diffusion stimulated by quasi-neutral drift, on the characteristics of structures is successively taken into account. The order of change in the carrier transport regimes in Schottky-diode structures is investigated and the features in the I–V characteristics caused by this change are established. The results of analytical study of these features are confirmed using numerical simulation.

Background. We have previously described an algorithm APhiG (Age of patients, Prostate health index and Gleason score), for staging of prostate cancer before treatment. The algorithm was developed by logistic regression on a training dataset and validated on a validation dataset (VD). Objective. Validation of threshold decision rules and a program for APhiG calculation on the VD.Materials and methods. ROC curve analysis on VD (83 cases).Results and conclusion. It was shown that sensitivity, specificity, positive and negative predictive value, diagnostic accuracy threshold decision rules and area under the curve (AUC) for APhiG in the VD (n = 83) not significantly different from those indicators in the training dataset (n = 337), which was the basis for the algorithm APhiG development.

The study was devoted to the creation of transparent electrodes based on highly conductive mesh structures. The analysis and reasonable choice of technological approaches to the production of such materials with a high Q factor (the ratio of transparency and electrical conductivity) were carried out. The developed manufacturing technology consists of the formation of grooves in a transparent substrate by photolithography methods, followed by reactive ion plasma etching and their metallization by chemical deposition using the silver mirror reaction. Experimental samples of a transparent electrode fabricated using this technology have a sheet resistance of about 0.1 Ω/sq with a light transmittance in the visible wavelength range of more than 60%.

The successful realization of high gain free-electron lasers has opened new possibilities to X-ray scientists for investigating matter in different states. The availability of unprecedented photon properties stimulated the development of new experimental techniques capable of taking full advantage of these options and has started a virtuous collaboration between machine experts and photon users to improve further and optimize the generated X-ray pulses. Over the recent years, this has led to the development of several advanced free-electron laser (FEL) schemes to tailor the photon properties to specific experimental demands. Presently, tunable wavelength X-ray pulses with extremely high brilliance and short pulse characteristics are a few of the many options available at FELs. Few facilities can offer options such as narrowband or extremely short pulses below one fs duration and simultaneous pulses of multiple colors enabling resonant X-ray pump—X-ray probe experiments with sub fs resolution. Fully coherent X-ray radiation (both spatial and temporal) can also be provided. This new option has stimulated the application of coherent control techniques to the X-ray world, allowing for experiments with few attoseconds resolution. FELs often operate at a relatively low repetition rate, typically on the order of tens of Hz. At FLASH and the European XFEL, however, the superconducting accelerators allow generating thousands of pulses per second. With the implementation of a new seeded FEL line and with an upgrade at FLASH linac, all the new features will become available in the soft X-ray spectral range down to the oxygen K edge with unprecedented average photon flux due to the high repetition rate of pulses.

The article examines important problematic issues of domestic bakery production. On the example of one of the bakeries of the Orel region, the changes in the list of production costs for the production of white bread for the period 1999-2019 are analyzed. The article discusses the benefits for the baking industry of canceling the return of unrealized bread from commercial enterprises. The reasons for the deterioration of the quality of wheat flour and white bread in the country's retail chains are considered. The problem of increasing the profitability of bakery production due to changes in the pricing policy is touched upon. The conditions for improving the financial condition of bakery enterprises, as well as the possibility of attracting investment in the industry, are considered.

This study proposes approaches aimed at methodological support for solving the problem of formalized evaluation of the effectiveness of regional higher education systems. The main feature of the work is the use of methods of comparison of «input» and «output» stream values characterizing the parameters of the functioning of the regional higher school. Using the approaches of regulation of the analyzed indicators and the subsequent development on this basis of indices of efficiency, are multi-component calculations that assess the level of generation output 1 unit output parameter, which identifies the financial-economic component of the regional high school. As a result of the implemented assessments, the regions of the Volga Federal district with moderate and strong positions in the sphere of generated effects characterizing their effectiveness in comparison with the invested financial resources are identified.

Detectors based on microchannel plates (MCPs) are used to detect radiation from free-electron lasers. Three MCP detectors have been developed by JINR for the European XFEL (SASE1, SASE2 and SASE3 lines). These detectors are designed to operate in a wide dynamic range from the level of spontaneous emission to the SASE saturation level (between a few nJ up to 25 mJ), in a wide wavelength range from 0.05 nm to 0.4 nm for SASE1 and SASE2, and from 0.4 nm to 4.43 nm for SASE3. The detectors measure photon pulse energies with an anode and a photodiode. The photon beam image is observed with an MCP imager with a phosphor screen. At present, the SASE1 and SASE3 MCP detectors are commissioned with XFEL beams. Calibration and first measurements of photon radiation in multibunch mode are performed with the SASE1 and SASE3 MCPs. The MCP detector for SASE2 and its electronics are installed in the XFEL tunnel, technically commissioned, and are now ready for acceptance tests with the X-ray beam.

The problem of ensuring the necessary level of availability of narcotic drugs (NLP) in the Russian Federation, especially in the framework of palliative medical care for oncological patients is the area of special and constant attention of the Government and civil society. Recently, a number of necessary changes of the legislation aimed at simplifying the procedures for prescribing and issuing NLP have been introduced, and the possibility of optimizing the rules for their storage and accounting as well as improving the methods for calculating the needs for such drugs are being actively discussed.As part of the import substitution program in Russia, the new dosage forms for NLP are under development. Such process is accompanied by clinical studies with a number of features that take into account the specific chemical composition of finished products.

Background. We have previously described an algorithm APhiGT (Age, Prostate Health index, Gleason score, TNM stage) for staging of prostate cancer (PC) before treatment. The algorithm was developed by logistic regression on an educational selection (ES) of 337 PC cases. The algorithm includes data about the age of patients, the levels of total prostate-specific antigen (PSA), free PSA, [-2]proPSA and the ranked data of the Gleason score (by biopsy results) and T (by TNM).Objective. Validation of APhiGT on the validation selection (VS) of 83 PC cases was carried out in this work.Materials and methods. ROC analysis was performed in ES and VS.Results and сonclusion. It is established that area under the curve (AUC), characterizing the ability to divide clinically significant subgroups of patients (Gleason score

We have conducted ground tests to study the applicability of the Tagged Neutrons Method/Associated Particle Imaging methodology (TNM/API) for the making precise gamma ray spectroscopic measurements onboard lander missions to the Solar system planets. Our analysis was focused on the requirement to distinguish between the spacecraft background and the subsurface signal so as to correctly evaluate the elemental composition of planetary soils. The measurements were performed in a configuration where the gamma spectrometer was surrounded by significant amounts of material that imitated a spacecraft structure. It was found that the TNM/API can substantially suppress the spacecraft background and identify the true intensities of the gamma lines attributed to major soil elements such as O, Na, Mg, Al, Si and Fe and evaluate their concentrations with an accuracy of 2–10%.

The article discusses the problems of state civil and municipal services effectiveness estimation at the regional level. Comparing the main indicators of the socio-economic development of the Republic of Tatarstan and other regions of the Privolzhsky Federal District and using the proposed estimated indicators, the authors try to trace the relationship between these indicators and the efficiency and effectiveness of public authorities and management in these regions. Formed versions of the ratings of the regions of the Privolzhsky Federal District, according to the authors, will allow identifying the relationship between the quality of public authorities and management and the state of the environment in the regions. A number of calculated indicators proposed by the authors can be applied within the region (at the level of municipalities) in the development of measures provided for by national projects for many areas of strategic development. In addition, the work focuses on increasing the professionalism of government and municipal employee.

The unambiguous application of fungal names is important to communicate scientific findings. Names are critical for (clinical) diagnostics, legal compliance, and regulatory controls, such as biosafety, food security, quarantine regulations, and industrial applications. Consequently, the stability of the taxonomic system and the traceability of nomenclatural changes is crucial for a broad range of users and taxonomists. The unambiguous application of names is assured by the preservation of nomenclatural history and the physical organisms representing a name. Fungi are extremely diverse in terms of ecology, lifestyle, and methods of study. Predominantly unicellular fungi known as yeasts are usually investigated as living cultures. Methods to characterize yeasts include physiological (growth) tests and experiments to induce a sexual morph; both methods require viable cultures. Thus, the preservation and availability of viable reference cultures are important, and cultures representing reference material are cited in species descriptions. Historical surveys revealed drawbacks and inconsistencies between past practices and modern requirements as stated in the International Code of Nomenclature for Algae, Fungi, and Plants (ICNafp). Improper typification of yeasts is a common problem, resulting in a large number invalid yeast species names. With this opinion letter, we address the problem that culturable microorganisms, notably some fungi and algae, require specific provisions under the ICNafp. We use yeasts as a prominent example of fungi known from cultures. But viable type material is important not only for yeasts, but also for other cultivable Fungi that are characterized by particular morphological structures (a specific type of spores), growth properties, and secondary metabolites. We summarize potential proposals which, in our opinion, will improve the stability of fungal names, in particular by protecting those names for which the reference material can be traced back to the original isolate.

User activities generate a significant number of poor-quality or irrelevant images and data vectors that cannot be processed in the main data processing pipeline or included in the training dataset. Such samples can be found with manual analysis by an expert or with anomalous detection algorithms. There are several formal definitions for the anomaly samples. For neural networks, the anomalous is usually defined as out-of-distribution samples. This work proposes methods for supervised and semi-supervised detection of out-of-distribution samples in image datasets. Our approach extends a typical neural network that solves the image classification problem. Thus, one neural network after extension can solve image classification and anomalous detection problems simultaneously. Proposed methods are based on the center loss and its effect on a deep feature distribution in a last hidden layer of the neural network. This paper provides an analysis of the proposed methods for the LeNet and EfficientNet-B0 on the MNIST and ImageNet-30 datasets.

High gain Free-electron lasers (FELs) are driven by linear accelerators that are currently capable of delivering electron bunches in high-repetition rates from kHz and up to several MHz. Short wavelength FELs are commonly operated in a self-amplified spontaneous emission (SASE) scheme which is, due to its stochastic nature, limited in temporal coherence. External seeding and harmonic generation techniques have been shown to be valid solutions for the generation of fully coherent and stable radiation up to the soft x-ray. However, the required seed lasers in the UV regime and shorter wavelengths cannot generate pulses with sufficient energy at the repetition-rates accessible with superconducting accelerators, hence the seed laser can become the limiting factor which determines the maximum repetition-rate for future seeded FEL based on superconducting linacs. In this paper, we address the need for generation of fully coherent radiation with higher average flux and we propose two different schemes which overcome the limitations and enable the generation of seeded radiation at high-repetitionrates. In one case, an optical cavity is used instead of the seed laser source. It retains a seed laser pulse and recirculates it to seed electron bunches in high-repetition-rates. In the other case, an optical klystron scheme is exploited in the seeding process: a low-intensity seed laser initiates the process in the first modulator and then, a dispersive section increases the density modulation and enables coherent emission in the second modulator which increases further the energy modulation. The resulting energy modulation is several times larger than the one possible with a standard seeding scheme and same laser intensity. Reducing the requirements in seed laser power, the proposed setup makes the use of seed lasers at higher repetition-rates or shorter wavelengths possible. Here, we show simulation results for the optical klystron scheme and we discuss experimental possibilities.

Prostate cancer is the second most frequent malignancy (after lung cancer). Preoperative staging of PCa is the basis for the selection of adequate treatment tactics. In particular, an urgent problem is the classification of indolent and aggressive forms of PCa in patients with the initial stages of the tumor process. To solve this problem, we propose to use a new binary classification machine-learning method. The proposed method of monotonic functions uses a model in which the disease’s form is determined by the severity of the patient’s condition. It is assumed that the patient’s condition is the easier, the less the deviation of the indicators from the normal values inherent in healthy people. This assumption means that the severity (form) of the disease can be represented by monotonic functions from the values of the deviation of the patient’s indicators beyond the normal range. The method is used to solve the problem of classifying patients with indolent and aggressive forms of prostate cancer according to pretreatment data. The learning algorithm is nonparametric. At the same time, it allows an explanation of the classification results in the form of a logical function. To do this, you should indicate to the algorithm either the threshold value of the probability of successful classification of patients with an indolent form of PCa, or the threshold value of the probability of misclassification of patients with an aggressive form of PCa disease. The examples of logical rules given in the article show that they are quite simple and can be easily interpreted in terms of preoperative indicators of the form of the disease.

Harmonic lasing provides an opportunity to extend the photon energy range of existing and planned x-ray free electron laser (FEL) user facilities. Contrary to nonlinear harmonic generation, harmonic lasing can generate a much more intense, stable, and narrow-band FEL beam. Another interesting application is harmonic lasing self-seeding that allows to improve the longitudinal coherence and spectral power of a self-amplified spontaneous emission FEL. This concept was tested at the soft x-ray FEL user facility FLASH in the range of 4.5–15 nm and at Pohang accelerator laboratory X-ray Free Electron Laser (XFEL) at 1 nm. In this paper we present recent results from the European XFEL where we successfully demonstrated harmonic lasing at 5.9 Angstrom and 2.8 Angstrom. In the latter case we obtained both third and fifth harmonic lasing and, for the first time, operated a harmonic lasing cascade (fifth-third-first harmonics of the undulator). These results pave the way for reaching very high photon energies, up to 100 keV.

Applied Sciences 11(18), 8495 (2021). doi:10.3390/app11188495, We demonstrate generation of X-ray Free-Electron Laser (XFEL) pulses in frequency mixing mode at the SASE3 line of the European XFEL. The majority of the SASE3 FEL segments are tuned at two frequencies ��1 and ��2 following an alternate pattern. Leveraging on non-linearities generated through longitudinal dispersion in the system, we obtain electron bunching at a frequency difference ��FM=��2�����1. FEL amplification at ��FM follows in a few last radiator segments. We report on the generation of frequency mixing at photon energies between 500 eV and 1100 eV with pulse energies, depending on the length of the radiator, in the mJ level. This method allows generating low photon energies in cases where the FEL runs at high electron energy and the target photon energy cannot be reached in the main undulator, with the simple addition of a short, custom-made afterburner., Published by MDPI, Basel

This paper describes a detailed simulation of the influence of optical imperfections in a multilayer Bragg mirror-based split-and-delay unit on the focused and unfocused beam profiles with relative time delays within the coherence time for hard X-ray pump/X-ray probe experiments at the European XFEL., For the High-Energy-Density (HED) beamline at the SASE2 undulator of the European XFEL, a hard X-ray split-and-delay unit (SDU) has been built enabling time-resolved pump/probe experiments with photon energies between 5 keV and 24 keV. The optical layout of the SDU is based on geometrical wavefront splitting and multilayer Bragg mirrors. Maximum delays between Δτ = ±1 ps at 24 keV and Δτ = ±23 ps at 5 keV will be possible. Time-dependent wavefront propagation simulations were performed by means of the Synchrotron Radiation Workshop (SRW) software in order to investigate the impact of the optical layout, including diffraction on the beam splitter and recombiner edges and the three-dimensional topography of all eight mirrors, on the spatio-temporal properties of the XFEL pulses. The radiation is generated from noise by the code FAST which simulates the self-amplified spontaneous emission (SASE) process. A fast Fourier transformation evaluation of the disturbed interference pattern yields for ideal mirror surfaces a coherence time of τc = 0.23 fs and deduces one of τc = 0.21 fs for the real mirrors, thus with an error of Δτ = 0.02 fs which is smaller than the deviation resulting from shot-to-shot fluctuations of SASE2 pulses. The wavefronts are focused by means of compound refractive lenses in order to achieve fluences of a few hundred mJ mm−2 within a spot width of 20 µm (FWHM) diameter. Coherence effects and optics imperfections increase the peak intensity between 200 and 400% for pulse delays within the coherence time. Additionally, the influence of two off-set mirrors in the HED beamline are discussed. Further, we show the fluence distribution for Δz = ±3 mm around the focal spot along the optical axis. The simulations show that the topographies of the mirrors of the SDU are good enough to support X-ray pump/X-ray probe experiments.

It is now a decade since The International Commission on the Taxonomy of Fungi (ICTF) produced an overview of requirements and best practices for describing a new fungal species. In the meantime the International Code of Nomenclature for algae, fungi, and plants (ICNafp) has changed from its former name (the International Code of Botanical Nomenclature) and introduced new formal requirements for valid publication of species scientific names, including the separation of provisions specific to Fungi and organisms treated as fungi in a new Chapter F. Equally transformative have been changes in the data collection, data dissemination, and analytical tools available to mycologists. This paper provides an updated and expanded discussion of current publication requirements along with best practices for the description of new fungal species and publication of new names and for improving accessibility of their associated metadata that have developed over the last 10 years. Additionally, we provide: (1) model papers for different fungal groups and circumstances; (2) a checklist to simplify meeting (i) the requirements of the ICNafp to ensure the effective, valid and legitimate publication of names of new taxa, and (ii) minimally accepted standards for description; and, (3) templates for preparing standardized species descriptions.

This paper considers the process of light propagation in a multimode optical waveguide being used in fiber-optic pressure sensors (FOPS). The Maxwell’s equations for the simplified geometry of bending are considered (for example, to represent it as sections of torus segments and "stitch" the solutions in different segments). Statistical modeling methods are used, for example, the Monte Carlo method to calculate a set of trajectories based on the solution of purely geometrical problems for finding intersection points and using Fresnel conditions in case of a refracting reflection point, or reflection from a surface with two radii of curvature in case of a tunneling reflection point. The research results will allow us to design and simulate a sensitive element of the sensor.

It is difficult to imagine modern airspace without unmanned aerial vehicles (UAV), or drones. The use drones both for state purposes and for the private ones is rapidly is rapidly expanded. A widespread use of UAV is due to a significant range of tasks to be solved. The drones are not only gradually displacing piloted aircrafts (used for searching seats of fire, checking the integrity of pipelines, detecting accidents and congestion on roads and rivers, etc.), but also find their application in the areas that were not included into the sphere of aviation earlier (for example, for delivery of smaller loads, or as an air taxi in future). The active development of the UAV market is inextricably linked with increased accidents caused by the rapid growth of the number of operated drones.

The article shows the relevance of the application of discrete models of rod structures of radio-electronic means (REM) for the study of their behaviour under transient loading. A discrete model of the propagation of harmonic waves in the rod and the study of standing waves are proposed. Computational experiments using the proposed model are conducted. The results show that the model accurately reflects qualitative dynamics of the physical processes in the elastic rod while the waves of elastic deformations are passing through. The proposed models are used for software implementations of systems of mechanical simulation of the behaviour of rod structures.

On the basis of numerical simulation, specificities of the effect of dU/dt in 4H–SiC thyristor structures, related to realization of the recently discovered triggering α-mechanism are analyzed. It is shown that one of the manifestations of this mechanism is a catastrophic reduction in the voltage blocked by a thyristor with an increase in temperature of the structure. Practical ways of eliminating this effect are discussed.

A technique for direct measurements of the current distribution over the surface of a target that is at a negative bias potential relative to the ground was developed and tested. Measurements were performed using a six-channel meter that transmitted the measured data through a wireless Bluetooth acquisition system. The trace of an ion flow on the target surface was visualized by the method of luminous beams. Examples of the measured current distributions on a target surface depending on the geometric and physical parameters of the ion-optical system of a Penning plasma source are presented.

A device based on a pulsed current generator with capacitive energy storage loaded on a plasma focus (PF) chamber is described. The device provides a discharge current amplitude of up to 2 MA in the PF chamber at a stored energy in the capacitor bank of up to 150 kJ. The PF chamber is designed to study hard X-ray (HXR) emission. It has windows for output of HXR emission in the cathode direction, as well as a special insert for output of HXR emission into the anode cavity. A study of operation of the chamber as a part of the setup with the use of various X-ray targets on the anode has been carried out. At a discharge current of 1.5MA, an HXR pulse with an average duration of 16 ns and energy spectrum from 10 to 200 keV, which provides an absorbed dose in the irradiated samples on the order of 1 Sv, is generated in the PF chamber.

The problem concerning the prediction of the aggressive status of prostate cancer (PCa) is examined on the basis of preoperative data. This problem is solved using data on 360 patients with the established (aggressive or indolent) postoperative status of the disease. The collection of factors containing five informative indicators of prediction (from primarily accessible sixteen) is revealed and employed to create the diagnostic index used to predict the aggressive PCa status. In compliance with cross-validation data, the prognostic algorithm enables us to find the group involving 55% of patients with an aggressive status in the absence of patients with an indolent PCa status. The three-class prediction algorithm making it possible to ascertain whether any patient belongs to the group with the low, high, or uncertain risk of the aggressive disease stage is proposed.

An analytical expression is derived for the current–voltage characteristic of a Schottky diode at a high injection level of minority carriers. It is shown that, even at very high current densities, the higher the base doping level, the larger the voltage drop across the diode. The physical mechanism responsible for this “paradoxical” result is analyzed. The validity of the analytical result is confirmed by a numerical calculation with software that takes into account the whole set of nonlinear effects caused by a high injection level in the base layer and by heavy doping of the emitter region.

This gauge was designed on the basis of a double-sided printed circuit board, which was used for forming its sensitive elements, capacitive reference gauge blocks, as well as all communication lines by the photolithography method with a high accuracy. Each meter of this level gauge is divided into eight continuous measurement sub-bands, ending with a reference gauge block, due to which an auto-calibration of each measurement sub-band with an absolute error of Δ = ±0.3 mm is carried out. An accuracy control with the help of reference gauge blocks is carried out in each measurement cycle evenly throughout the whole range of level measurement of the controlled liquid. A technique has been developed for designing a discrete-continuous capacitive level gauge for a wide class of dielectric liquids with complex manufacturing of sensitive elements and gauge communication lines based on a one-meter printed circuit board. A simple design of the level gauge and manufacturing of sensitive elements in the form of printed circuit boards, and the presence of embedded auto-calibration provide the gauge with initially high metrological characteristics along with low cost of its manufacture.

Applied Sciences 10(8), 2728 (2020). doi:10.3390/app10082728, X-ray pump/X-ray probe applications are made possible at X-ray Free Electron Laser (XFEL) facilities by generating two X-ray pulses with different wavelengths and controllable temporal delay. In order to enable this capability at the European XFEL, an upgrade project to equip the soft X-ray SASE3 beamline with a magnetic chicane is underway. In the present paper we describe the status of the project, its scientific focus and expected performance, including start-to-end simulations of the photon beam transport up to the sample, as well as recent experimental results demonstrating two-color lasing at photon energies of 805 eV + 835 eV and 910 eV + 950 eV. Additionally, we discuss methods to analyze the spectral properties and the intensity of the generated radiation to provide on-line diagnostics for future user experiments., Published by MDPI, Basel

Backgrounds. The object of the study is the aspects leading to more intensive mixing of the gas, for the most complete combustion of the formed turbulent jet, which is used in combustion processes. The subject of the study is the model for finding the most optimal concentration of mixing gases. The aim of the work is the use of models for determining the concentrations of stirring gases for an automated control system of furnace equipment. Materials and methods. Mathematical modeling with the use of the laws of conservation of substances and chemical aerothermodynamics, analytical and numerical solution of problems, computational experiment. Results. The problem of diffusion combustion of two gas-air mixtures was formulated - the symbiosis of models of diffusion and homogeneous combustion regimes in a turbulent flow. A concentration determination model was developed for an automated component supply system for diffusion combustion of a mixture, and the theoretical and practical applicability of the proposed model was determined. Conclusions. The technologies considered are potentially applicable in the system of automated control of combustion processes and a high assessment of their effectiveness is shown.

Nature photonics 14(6), 391 - 397 (2020). doi:10.1038/s41566-020-0607-z, The European XFEL is a hard X-ray free-electron laser (FEL) based on a high-electron-energy superconducting linear accelerator. The superconducting technology allows for the acceleration of many electron bunches within one radio-frequency pulse of the accelerating voltage and, in turn, for the generation of a large number of hard X-ray pulses. We report on the performance of the European XFEL accelerator with up to 5,000 electron bunches per second and demonstrating a full energy of 17.5 GeV. Feedback mechanisms enable stabilization of the electron beam delivery at the FEL undulator in space and time. The measured FEL gain curve at 9.3 keV is in good agreement with predictions for saturated FEL radiation. Hard X-ray lasing was achieved between 7 keV and 14 keV with pulse energies of up to 2.0 mJ. Using the high repetition rate, an FEL beam with 6 W average power was created., Published by Nature Publ. Group, London [u.a.]

The impact of non-1D effects caused by the spread of the gate current in the base layer on the gate switch-on current in 4H-SiC thyristors is considered. It is shown that a new switching mechanism implemented in 4H-SiC thyristors results in the dependence of the gate switch-on current on the thyristor parameters, with this dependence being fundamentally different from that in conventional silicon thyristors.

Serum of 336 patients with primary prostate cancer (PC) with baseline total prostate-specific antigen level (totPSA) < 30.0 ng/ml was tested for free PSA (freePSA) and [-2]proPSA; %freePSA, %[-2]proPSA, prostate health index (phi), and a new index APHIG calculated using lab tests and taking into account age, T stage and Gleason score from biopsy were evaluated. Obtained data was compared to tumor stage (pTNM) and malignancy grade according to the Gleason score based on the final histological report after prostatectomy. APHIG has statistically significant benefits compared to PSA-associated markers for differentiation of clinically significant subgroups of PC: pT2c/pT3a/pT3b; local indolent PC/local aggressive/locally advanced/PC with regional metastases; total Gleason score 5–6/7(3 + 4)/7(4 + 3).