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Experimental investigation has been carried out for laser ignition and combustion of nanothermites based on aluminum and oxides of copper, bismuth and molybdenum. Ultrasonic mixing of nanosized powders was used to produce compositions. For thermite ignition, initiating laser pulse with a maximum intensity of 770 W/cm2 was generated by a laser diode with a wavelength of 808 nm. The ignition delay times, the minimum initiation energy density, and the average burning rate at various thermite densities and mass fractions of components were determined by recording the emission of radiation of the reaction products using a multichannel pyrometer jointly with a high-speed video camera. The effect of adding carbon black on the threshold parameters of a laser pulse was also studied. Based on the obtained results, certain assumptions were put forward with regard to the mechanism of nanothermites’ ignition by laser radiation and their burning. In particular, the assumptions were made on the two-stage process of the reaction initiation and jet burning mechanism of porous nanothermites.

PurposeThis study aims to conduct a systematic review and critically analyze the sentiment analysis literature in hospitality and tourism from methodological (data sets and analyzes) and thematic (topics, theories, key constructs and their relationships) perspectives.Design/methodology/approachQualitative thematic review and quantitative systematic review were performed on 70 papers obtained from hospitality and tourism categories of two databases, namely, Web of Science and Scopus.FindingsA total of 5 topics and 27 sub-topics were identified and the major theme is market intelligence. Sentiment variables were investigated not only as independent but also as dependent variables. The customer rating is the most investigated dependent variable, whereas moderators and mediators were rarely tested. Most reviewed studies did not use theory. The findings from the methodological review show that analysis of big data was rare. Moreover, testing the performance of sentiment analyzes was uncommon, and only one paper tested the performance of aspect/feature extraction.Research limitations/implicationsThis study extends prior review studies by providing a comprehensive view of how knowledge and methodologies of sentiment analysis have developed. The identified themes and key constructs serve as a solid base for future knowledge advancement. Future research directions on sentiment analysis are also provided.Originality/valueTo the best of the authors’ knowledge, this study is the first comprehensive methodological and thematic review of sentiment analysis in hospitality and tourism. Based on the identified findings, the authors propose several directions for future research.

An adaptive low-pass filter has been synthesized for automatic patterns detection of arbitrary mental movements in records of multidimensional electroencephalograms (EEG). The filter is based on the multivariate singular spectrum analysis. The effective bandwidth of the filter corresponds to the spectrum of the sought patterns of mental activity on the observed EEG time interval. The use of the synthesized filter provided a reliable automatic search for patterns and the correct determination of their time boundaries. The correctness of the results has been confirmed in experiments with 24 volunteers.

With the increasing integration of renewable energy sources (RESs) and the implementation of dynamic line rating (DLR), the accompanying uncertainties in power systems require intensive management to ensure reliable and secure operational planning. However, while numerous approaches and methods in the literature deal with uncertainties, they have not been analyzed axiomatically. This paper presents an analysis of risk in power system operation using coherent risk measures, elaborating on the origin of risk and the mechanisms of its management in the presence of various sources of uncertainty. To illustrate the practicality and benefits of coherent risk measures, a risk-averse asymmetry robust unit commitment (UC) model is established. It is based on coherent reformulations of the uncertain reserve and line flow constraints and is formulated in the form of a compact computationally efficient mixed-integer second-order conic program (SOCP). The overall performance of the proposed framework is verified using the updated 2019 IEEE Reliability Test System and the ACTIVSg2000 test system over a year-long period.

The article analyzes the main ideas of the philosopher S. Khoruzhiy, that contribute to the development of contemporary philosophy. The author analyzes the principle of anthropological opening, the role of spiritual practices in the philosophical system of S. Khorushiy. He also considers the concepts of transformative anthropology, the discourse of synergy, virtuality and technological development worked out by the philosopher. To show how the philosopher’s ideas can work, the author attempts to interpret the synergistic discourse of the selfhood with regard to the key provisions of synergic anthropology.

The experiment was performed on 2 samples of the pig's cervical spine. 12 transpedicular screws were implanted using navigation templates. The safety and accuracy of installation of screws were evaluated by analyzing the results of computed tomography. 12 screws had a level of implantation safety of 0 degree – the screw was completely inside the bone structures of the vertebra. The accuracy of the implanted screws was evaluated by determining the degree of deviation of the obtained screw trajectory from the planned one. The resulting accuracy of the installed screws is 91 % and corresponds to class 1. At standard deviation, there were no significant differences in the axial and sagittal angles between the planned installation and the actual trajectory of the screw for the subaxial cervical spine on the left and right. There were no significant differences in the standard deviation in the axial projection at the points of entry and intended exit of the screw. Statistical analysis did not reveal significant differences between planned and actual results (P > 0.05).

In the context of global changes in the media market under the influence of Internet technologies, it becomes necessary to identify the main trends of its development, so the characteristic of the market trends, the integration process of entrepreneurial structures in the media industry, aimed at increasing their competitiveness at the present stage of development of the market economy. In the context of an ever-changing, competitive digital ecosystem and against the background of General cuts in advertising budgets in the print press, radio, and television, advertising investments in the digital environment are increasing starting in 2019. Revenues of legacy news media organizations (also called old or traditional media organizations) are constantly declining due to the high degree of audience participation in new media due to the use of user-generated content, media automation, and new digital media organizations. Using mathematical-statistical and logical research methods, the article identifies specific features of the media business sphere, which include audience fragmentation, culture of creative destruction, and hypercompetition in the media market. In addition, key issues and current changes in the media industry in the context of global digitalization are highlighted, reflecting the introduction of innovative technologies that affect the media industry, and the decline in traditional methods of delivery and media consumption. Global digitalization has affected the growth of media platforms, resulting in an increase in the supply of content itself, as well as significant changes in its consumption by the advertising market.

The mid-infrared (IR)-sensitive n/p-junction was fabricated on a p-doped silicon (Si) wafer via ultrashort laser n-type surface hyperdoping and high-temperature annealing. First, the n-type sulfur ...

The polarization plane rotators located outside the transmission line volume are presented. Their work is based on the excitation of special (‘dihedral') eigen-oscillations in a waveguide object fo...

Purpose: to build a hierarchical classification of microhydroelectric power plants, the elements of which are considered as an eventual component of the hydroreclamation system for converting the energy of water flow and solving energy efficiency and energy conservation issues in the reclamation complex. Materials and methods. The source materials used were the works of Russian and foreign researchers in the field of hydroelectric power plants use, as well as its design. Such methods as analysis, synthesis, logic, and classification were used as information processing and classification methods. Results and discussion. The issues of energy efficiency and energy conservation in the reclamation complex require the use of new constructive, technological approaches, and the use of profound convergence between knowledge in the energy industry and land reclamation will allow solving some of them. As a result of the search, processing and analysis of information sources in the field of the use and design of hydroelectric power plants, the absence of a general hierarchical classification of microhydroelectric power plants was stated, that causes certain difficulties in integrating a single microhydroelectric power station into the hydroreclamation system as its element. The conducted research related to the development of a hierarchical classification of microhydroelectric power plants made it possible to identify the necessary objects according to three classification criteria: the presence (absence) of head, the principle of supplying a water resource to a hydraulic unit, and the turbine design. Conclusions. The developed four-level hierarchical classification can be adopted at a first approximation, as a basis for systematizing information on microhydroelectric power stations and can be further used in the design of reclamation systems taking into account energy efficiency and energy conservation elements and can also be the object of further discussion.

Application of grafts for bone grafting is essential for spine surgery, traumatology and orthopedics, oncology, maxillofacial surgery. However, there is no ideal graft that would have all the necessary properties (osteogenic, osteoconductive, osteoinductive) and it would not have significant disadvantages. At spinal surgery, high-speed bone milling machines are used during decompression. In the case of bone tissue resection an equivalent amount of bone chips appears which is routinely aspirated and disposed of together with blood and destroyed tissues. At the same time at bone grafting there is a shortage of local graft material. Objective: to acquaint readers with the possibility of obtaining bone grafts with the help of the developed device as a high-speed bone surgical reamer during spinal fusion. Methods: a device for filtering bone chips is created, consisting of a flask and a filter element inside it, connected in parallel to the aspiration system. The device allows preserving a sufficient amount of bone-grafting material, which consists of bone tissue elements, fibrin clot, bone marrow cells, platelets, mesenchymal stromal cells and others. Results: a clinical example of its application at transforaminal interbody fusion at the level of the lumbar segment LIV–LV is presented. The device differs favorably from the known ease of assembly, reusability (possibility of repeated sterilization) and placement on the operating table. Conclusions: the application of a bone filter is appropriate in the case of spine decompression of a high-speed bone reamer, when the stage of surgery is bone grafting. Do not use the device in case of spine tumors, spondylitis, spondylodiscitis.

Aim. To study the opinion of mothers of newborns and neonatologists about the organization of inpatient care for newborns in St. Petersburg. Methods. An anonymous survey of 2123 mothers of newborns and 172 neonatologists of St. Petersburg was conducted. The representativeness of the sample was checked by using the method of Professor A.M. Merkov, with the errors do not exceed 4 and 3%, respectively. Mathematical processing and data analysis were carried out by using the statistical software package PASW STATISTICS. Results. 28.9% of mothers were partially or completely unsatisfied with the organization of inpatient care for newborns, in most cases due to the unfriendly and inattentive attitude by the medical staff (22.4%), the unsatisfactory provision by child care products (12.8%) and poor material and technical equipment of a medical organization (12.5%). On average, the human qualities of neonatologists were rated quite high by mothers at 4.630.09 (out of 5) points, and in mid-level practitioners were significantly lower 3.910.08 points (p 0.05). In general, staying a newborn in a medical organization required financial costs for 37.3% of women, and 13.9% of respondents who received help through compulsory medical insurance paid for individual laboratory and other tests on their own. Mothers rated the organization of inpatient care for newborns on average 4.010.09 points. Compared to mothers, neonatologists rated it higher in the medical organization they work for and lower overall in St. Petersburg (M=4.110.10 points and M=3.780.12 points; p 0.05). According to the doctors, the main disadvantages of organizing inpatient care for newborns are poor material and technical equipment and problems associated with the staffing and qualifications of medical personnel. Conclusion. There is a need to improve the process of providing inpatient care to newborns.

The global competition, unstable situation in the world market of rolled metal products, as well as increasing with each day the requirements of consumers of products pose complex tasks for the manufacturer, which must be solved in the shortest possible time. One of these tasks is to expand the range of rebar rolled products in the conditions of the variety rolling shop no. 1 on the continuous small-grade rolling mill 320. Until recently, rolling of reinforcing profiles with a diameter from 10 mm to 40 mm was carried out at the 320 rolling mill. In order to expand the range of rebar products, work was carried out to develop a production technology for profile no. 8 rod fittings with thermal hardening in the mill line for class 500.

The variety of contemporary systems of healthcare, as well as practices and methods of healing in the modern world of many cultures, has led to the issue of their intercompatibility. In the study of the way Tuvans experience health this problem gives rise to the concern whether the way Tuvan youth imagines health as part of their life and world has been able to survive in the situation when it has to coexist with both alternative non-conventional healing practices and conventional medicine.For its empirical basis, our study relied on ten semi-formal interviews (2019) with ethnic Tuvans from the Republic of Tuva who came to Tomsk to study at the local branch of the Russian State University of Justice. The study’s aim was to describe the experience and practices of preserving health among Tuvan students and the variability of this experience. Methodological foundation of the study was found in Alfred Schutz’s paradigm of social phenomenology and aimed at “providing qualitative descriptions of the interlocutor’s lifeworld” (S. Kvale).The study has revealed that the cultural background of the respondents helped them understand health as linked to the following topics: “natural” character of their lifeworld; its sacral status; the experience of the magical in healing practices; the feeling of belonging to ancestral tradition; ritual organization of life; holistic understanding of health as an entity combining religious, metaphysical, aesthetic and practical aspects. Of special interest is the practice of weaving together pieces of thread to be worn around the wrist. Many respondents mentioned this as a symbol of health, protection and welfare.Their experience of preserving good health puts respondents into the situation of what may be described as “medical syncretism”: treatment in a state-run medical institution may well be combined with non-conventional medicine, with emphasis placed on traditional treatments and folk medicine. In the attitudes towards their health, Tuvan students show both the “fundamentalist” (following their cultural traditions) and the “modernist” (leaving these traditions behind) trends.

Semiconductor nanowires exhibit numerous capabilities to advance the development of future optoelectronic devices. Among the III-V material family, gallium phosphide (GaP) is an attractive platform with low optical absorption and high nonlinear susceptibility, making it especially promising for nanophotonic applications. However, investigation of single nanostructures and their waveguiding properties remains challenging owing to typically planar experimental arrangements. Here we study the linear and nonlinear waveguiding optical properties of a single GaP nanowire in a special experimental layout, where an optically trapped structure is aligned along its major axis. We demonstrate efficient second harmonic generation in individual nanowires and unravel phase matching conditions, linking between linear guiding properties of the structure and its nonlinear tensorial susceptibility. The capability to pick up single nanowires, sort them with the aid of optomechanical manipulation and accurately position pre-tested structures opens a new avenue for the generation of optoelectronic origami-type devices.

Mobile microscopy is a newly formed field that emerged from a combination of optical microscopy capabilities and spread, functionality, and ever-increasing computing resources of mobile devices. Despite the idea of creating a system that would successfully merge a microscope, numerous computer vision methods, and a mobile device is regularly examined, the resulting implementations still require the presence of a qualified operator to control specimen digitization. In this paper, we address the task of surpassing this constraint and present a “smart” mobile microscope concept aimed at automatic digitization of the most valuable visual information about the specimen. We perform this through combining automated microscope setup control and classic techniques such as auto-focusing, in-focus filtering, and focus-stacking—adapted and optimized as parts of a mobile cross-platform library.

We fabricated indium gallium nitride (InGaN) red light-emitting diodes (LEDs) with a peak emission wavelength of 649 nm and investigated their electroluminescence (EL) properties. An additional separated peak in the EL spectrum of the red LEDs at 20 mA was observed at 465 nm. This additional peak also exhibits a blue-shift with increasing currents as does the main emission peak. Using high-resolution microscopy, we observed many point-like emission spots in the EL emission images at the currents below 1 mA. However, these emission spots cannot be identified at currents above 5 mA because the red emission from quantum wells (QWs) is much stronger than that emitted by these spots. Finally, we demonstrate that these emission spots are related to the defects generated in red QWs. The measured In content was lower at the vicinity of the defects, which was regarded as the reason for separated short-wavelength emission in red InGaN LEDs.

The article reveals the ideas of forming a culture of health, prevention of bad habits of students (tobacco smoking, alcoholism, drug addiction) by means of methodical tips and recommendations in a healthу environment of high school, which educate the quality of the person reflecting the nature of the interested person lifestyle and environment.It is possible to create a culture of health for future teachers when they are focused on health care through the pedagogical education system itself. The pedagogical effect should not only consist in the accumulation of new knowledge, skills, development of a positive motivational attitude to health, but also be expressed in self-development, self-education, self-realization and self-activity. Therefore, there is a need to include future professionals in specially organized and diverse activities where their need to act for the sake of health is formed. You need to create the conditions for individuals to gain experience in maintaining and promoting health.The future teacher teacher's health culture is part of a general future teacher's culture that encompasses pedagogical, psychological, medical, legal, and social aspects. It is a positive health result that ensures the unity of the physical, mental, spiritual and social development of the individual.

Managers of protected areas that are popular among tourists need to combine conservation goals with assurances of visitor safety while providing high-quality service. The compromise amongst these g...

Objective: to evaluate the innovative organizational, medical and pharmacoepidemiological approaches for the prevention of circulatory system diseases in pre-primary care using mobile health technologies.Materials and methods: 3,694 people went through preventive consultation (questionnaires, anthropometry, body fat and blood pressure evaluation, electrocardiography, glucose and blood cholesterol) at equipped medical sites in shopping centers and rural health posts.Results. Among the surveyed, there were both healthy people and patients cardiovascular diseases and diabetes mellitus. Behavioral (insufficient consumption of fruits and vegetables, adding more salt without trying food, physical inactivity, smoking and alcohol abuse) and nutritional (obesity, hypertension, hypercholesterolemia and glycaemia) risk factors of chronic noncommunicable diseases were detected that contribute to high mortality from circulatory system diseases in the Tver region. This is associated with low adherence to drug therapy and its lack of efficacy in patients with hypertension, ischemic heart disease and cerebrovascular diseases.Conclusion: to assess the effectiveness of CSD prevention in pre-primary care, it is possible to use mobile medical sites in shopping centers and rural health posts.

In the context of rising energy costs and the need to use new energy sources, works aimed at raising the surface temperature of heat radiators with reduced energy consumption are of particular importance, and it is especially important if these processes are also accompanied by the effects of self-stabilization. Bulk materials do not possess these properties. However, materials whose dielectric matrix is also an active element can provide up to 10 - 30% of the thermal energy that will be released in the material, thereby increasing the surface temperature and without increasing energy consumption. Therefore, the study of composite materials with different matrices is relevant. This article the influence of the matrix material on the electrical properties of composite materials was examined. It was established that the microstructure morphology of resistive materials changes significantly depending on the matrix type. In composites based on matrix AlN, for the entire range of concentrations HfC, conducting cluster is formed with a metallic conductivity. For composite systems Al2O3-HfC and Si3N4-HfC thermoactivated hopping conduction between nearest neighboring states observed. Thus, for materials based on Si3N4 matrix at temperatures up to 300°C observed reduction of charge carriers concentration with increasing temperature. The approximation of the temperature dependence of the electrical conductivity was carried out on the basis of the following possible variants of the nature of the electrical conductivity, namely: jump conductivity (nonlocalized states, localized states in the tails of conduction and valence bands, localized states near the Fermi level), tunneling. It can be assumed that the formation of conductive clusters occurred under the influence of two factors: magnetic field and mechanical loading. When using the AlN matrix, the influence of the magnetic field on the structure formation is smallest. This conclusion can be drawn from the fact that the formed conductive clusters have the appearance of a linear chain structure.

Purpose: Technical capabilities of the MARK-4B antenna system necessary for its further using as a 32-meter radiotelescope (RT-32) and making simultaneous spectral radioastronomical observations in the C and K frequency ranges, are investigated. Design/methodology/approach:The studies use the results of our own measurements made with the МАRK-4В antenna system, expert reviews, open information sources, technical documentation of the MARK-4B antenna system, radio astronomy and computer simulation methods and comparative analysis of this antenna main parameters with the corresponding parameters of the world’s best active radio telescopes. Combining different approaches allows us to determine the requirements for the receiving system, parameters of the spectrometer, calibration techniques and optimize the МАRK-4В antenna system modernization procedure. Findings: The radio telescope main parameters required for spectral observations in the C and K frequency ranges are determined. The antenna pointing system capabilities are specified. For the MARK-4B antenna system working frequency range, the main spectral lines of various molecules available for research have been considered. The transitions radiating the most intensive spectral lines are listed. The radio astronomical problems that can be solved using the MARK-4B in the mode of spectral observations are formulated. The required parameters of the spectrum analyzer and the receiver’s self-noise temperature are determined. Calibration techniques of the recorded signal are described, which are necessary for carrying out spectral observations. Conclusions: The here presented studies show that for making spectral observations based on the beam-waveguide MARK-4B antenna system, it is technically possible to create the RT-32 radio telescope with quality technical characteristics corresponding to the world-best analogs. Modernization of the beamwaveguide MARK-4B antenna system will allow at the first stage to create in Ukraine the dual-band radio-telescope permitting to make simultaneous spectral and/or continued observations in the C and K ranges. Henceforth, the amount of simultaneously working ranges can be increased.

The TAIGA (Tunka Advanced Instrument for cosmic ray physics and Gamma-ray Astronomy) experiment aims at observing gamma-rays in the energy range from 1 TeV to several 100 TeV. The operation of the observatory is based on a new hybrid approach that combines imaging air Cherenkov telescopes (IACTs) and wide-angle Cherenkov detectors (TAIGA-HiSCORE) for measuring times of extensive air shower (EAS) light front arrival. Monte Carlo simulations are compared to real data to determine the performance of the detector setup. Dedicated software and algorithms are described, model parameters are given, and an overview of the current status of model-based performance studies is presented.

The results of studies of the structural and optical properties of two-dimensional GaSe layers grown by molecular-beam epitaxy on GaAs(001) and GaAs(112) substrates using a valve cracking cell for the Se source are reported. The influence of the MBE growth parameters (the substrate temperature, Ga flux intensity, Se/Ga incident flux ratio) on the surface morphology of the layers is studied. By means of transmission electron microscopy, electron diffraction technique, and Raman spectroscopy, it is shown that the structure of the GaSe layers corresponds to the γ-GaSe polytype. From X-ray diffraction analysis, it is established that there exist α-Ga2Se3 inclusions in the GaSe layers grown under conditions of high enrichment of the growth surface with Se.

The study examines the online public response to a high visibility incident of service failure from the crisis communication and image restoration perspectives. A specific incident in a hotel of a popular chain in Beijing, China, which was widely publicized on Chinese social network Weibo, is used as an example. Applying data mining and GIS to the collected data, the study analyzes temporal, spatial, topical, and gender dynamics of public discussions to investigate the usefulness of such data for hospitality providers in crisis. The study finds evidence that the effect of the incident on the general public is moderated by spatial and personal proximity of Weibo users. The discussion topics reflect the nature of the crisis and are affected by communications from the service provider and third parties. Implications for providers of tourism and hospitality services in a crisis of high visibility are discussed.

Online public discussions of service failure incidents might result in significant reputational damage for service providers. This study examines the geographical and personal proximity fac...

The review is devoted to the generalization and analysis of domestic and foreign works describing the mechanism of development of neurogenic dysfunction of the bladder after surgery on the pelvic organs in cancer patients. All modern authors agree that the cause of these disorders is trauma of the pelvic nerves and interruption of the reflex arc. Unfortunately, when removing malignant tumors of the pelvic organs, urological complications are difficult and often impossible to avoid. This is due to the complex neuroanatomy of the bladder, its proximity to the rectum, the uterus, as well as the volume and radicality of cancer operations. The article shows that if the parasympathetic ganglia are damaged, there is a violation of the evacuation function of the bladder and a weakening or absence of the urge to urinate. If the sympathetic nervous system is damaged in isolation, on the contrary, an increase in the detrusor tone, intravesical pressure and a decrease in the capacity of the bladder is observed, which is in conditions of low bladder sphincter tone causes imperative urges, frequent urination and incontinence. Prior radiation therapy also affects the development of urological complications. Postradiated soft tissue changes, ischemia, fibrosis lead to great technical difficulties during surgery. In addition, factors that are important in the development of pelvic disorders in this category of patients include urinary system diseases and metabolic – endocrine disorders in case history.

The choice of optimal graft is the basis for successful spine fusion formation. In article reviewed different graft with their positive and negative features.

Multigraphene films have been for the first time obtained on the surface of quartz glass via carbonization of polyimide Langmuir–Blodgett films. The Raman spectra of the films show bands G and D and a broad band at 2300–3200 cm–1, which are characteristic of graphite-like films. The transmission electron microscopy demonstrated that the films are constituted by “stacks” of layers spaced by 0.36 nm. The surface resistance of the 5-nm-thick films was 1.2 ± 0.2 kΩ, and the transmittance was 87% at λ = 550 nm. The transmittance was 97% in the IR part of the spectrum and 70–80% in the UV part.

Tourism is one of the sectors of the economy that is most dependent on climate, creating multiple vulnerabilities and new opportunities arising with changing climate. Even though the links between tourism and climate have been well researched, this scientific knowledge has not percolated into policies and the ability to act. This disconnect between scientific knowledge and practices is frequently blamed on inadequate climate change communication to the public in mass media. We studied the mass media framing of climate change and tourism by analyzing English newspaper publications worldwide over the past 30 years. The paper presents a Big Data analysis of the content, geographical patterns, and temporal changes in newspapers’ publications on climate change and tourism.

The possibility to design a tunable polarization plane (PP) rotator in waveguides with circular symmetry is proven. The appearance of artificial “optical activity” in the interaction of a pair of conjugated planar chiral irises by the fringing fields is used. The rotator can be reconfigured by rotating the irises relative to each other providing the rotation of the PP up to cross-one. Being relatively narrowband, the rotator has a longitudinal dimension $\lambda _{0}/50$ – $\lambda _{0}/10$ .

Light-emitting organic field-effect transistors (LE-FETs) on the basis of composite films that consist of perovskite nanocrystals (CsPbBr3) embedded in a matrix of conjugated polymer—polyfluorene (PFO)—have been obtained, and their electrical and optical properties have been investigated. Output and transfer current-voltage characteristics (I-Vs) of FETs based on PFO : CsPbBr3 films (component ratio 1 : 1) have a slight hysteresis at temperatures of 100–300 K and are characteristic of hole transport. The hole mobility is ∼3.3 and ∼1.9 cm2/(V s) at the modes of the saturation and low fields, respectively, at 250 K and reaches ∼5 cm2/(V s) at 100 K. It has been shown that the application of pulsed voltage to LE-FETs based on PFO : CsPbBr3 can reduce the ionic conductivity and provide electroluminescence in this structure at 300 K.

Tailorable synthesis of III-V semiconductor heterostructures in nanowires (NWs) enables new approaches with respect to designing photonic and electronic devices at the nanoscale. We present a comprehensive study of highly controllable self-catalyzed growth of gallium phosphide (GaP) NWs on template-free silicon (111) substrates by molecular beam epitaxy. We report the approach to form the silicon oxide layer, which reproducibly provides a high yield of vertical GaP NWs and control over the NW surface density without a pre-patterned growth mask. Above that, we present the strategy for controlling both GaP NW length and diameter independently in single- or two-staged self-catalyzed growth. The proposed approach can be extended to other III-V NWs.

Laser-induced periodic surface structures (LIPSS) can be fabricated in virtually all types of solid materials and show great promise for efficient and scalable production of surface patterns with applications in various fields from photonics to engineering. While the majority of LIPSS manifest as modifications of the surface relief, in special cases, laser impact can also lead to periodic modulation of the material phase state. Here, we report on the fabrication of high-quality periodic structures in the films of phase-change material Ge2Sb2Te5 (GST). Due to considerable contrast of the refractive index of GST in its crystalline and amorphous states, the fabricated structures provide strong spatial modulation of the optical properties, which facilitates their applications. By changing the excitation laser wavelength, we observe the scaling of the grating period as well as transition between formation of different types of LIPSS. We optimize the laser exposure routine to achieve large-scale high-quality phase-change gratings with controllable period and demonstrate their reversible tunability through intermediate amorphization steps. Our results reveal the prospects of fast and rewritable fabrication of high-quality periodic structures for photonics and can serve as a guideline for further development of phase-change material-based optical elements.

Control and analysis of the crystal phase in semiconductor nanowires are of high importance due to the new possibilities for strain and band gap engineering for advanced nanoelectronic and nanophotonic devices. In this letter, we report the growth of the self-catalyzed GaP nanowires with a high concentration of wurtzite phase by molecular beam epitaxy on Si (111) and investigate their crystallinity. Varying the growth temperature and V/III flux ratio, we obtained wurtzite polytype segments with thicknesses in the range from several tens to 500 nm, which demonstrates the high potential of the phase bandgap engineering with highly crystalline self-catalyzed phosphide nanowires. The formation of rotational twins and wurtzite polymorph in vertical nanowires was observed through complex approach based on transmission electron microscopy, powder X-ray diffraction, and reciprocal space mapping. The phase composition, volume fraction of the crystalline phases, and wurtzite GaP lattice parameters were analyzed for the nanowires detached from the substrate. It is shown that the wurtzite phase formation occurs only in the vertically-oriented nanowires during vapor-liquid-solid growth, while the wurtzite phase is absent in GaP islands parasitically grown via the vapor-solid mechanism. The proposed approach can be used for the quantitative evaluation of the mean volume fraction of polytypic phase segments in heterostructured nanowires that are highly desirable for the optimization of growth technologies.

The LEDs were obtained that the peak emission wavelength and FWHM were 665 nm and 67 nm at 20 mA, respectively. It exhibited a large blueshift of the EL peak wavelength from 691 nm at 5 mA to 631 nm at 100 mA. In this range, the blue-shifted value was 60 nm. Besides, we realized the single peak emission LEDs without an additional emission. We obtained a light output, forward voltage, and EQE of 0.07 mW, 2.45 V, and 0.19% at 20 mA, respectively. The LEDs exhibited the temperature stability of EL intensity and peak wavelength.

We obtained the EL intensity enhancement by a factor of 1.3 with increasing of n-GaN thickness from 2 to 8 µm. We achieved a light output, forward voltage, FWHM and external quantum efficiency of 0.64 mW, 3.3 V, 59 nm, and 1.6% at 20 mA, respectively. Particularly, the wall plug efficiency was 1.0%, which is comparable with the state-of-the-art InGaN-based red LEDs. The reduction of the in-plane compressive stress by the GaN underlying layers appears to be crucial for enhancing the light output of InGaN-based red LEDs on conventional sapphire substrates.

Purpose: to realize integration of the innovative organization mechanism with the system of standard design of reclamation facilities with subsequent visualization of the interaction processes of the system elements in the form of a functional model. The organization mechanism in the innovation activity is an activity aimed at the formation and, if necessary, reorganization of structures that implement innovation processes. Materials and methods. The works of Russian and foreign researchers in the field of application of innovative mechanisms in various sectors of economy were used as initial materials. The following methods of information processing were used: analysis, synthesis, logic. When constructing a functional model of interaction of system structural elements, the methodology of functional modeling was used in accordance with R 50.1.028-2001. Results and discussion. It is proposed to divide the developed structure of a convergent standard design system into three component parts, in particular, developers of standard project documentation, an organization for managing standard project documentation (institution), consumers of standard project documentation, with the subsequent endowment of each of the elements with their own areas of activity. The analysis of the activity of the elements of the system is carried out, highlighting the main functions performed. A functional model of interaction of a convergent standard design system elements has been developed. Conclusions. The core structural element of the converged system in the form of an organization for managing standard design documentation (institution), while performing its main functions, will ensure the interaction of developers and consumers of standard design documentation at a higher quality level compared to the previously existing (under the Soviet Union) standard design system.

This article deals with topical issues of effective regulation of agriculture, the development of a set of operational–search and other measures aimed at protecting and protecting the budget funds allocated by the state for the development of the agro–industrial complex.

Purpose: to assess the potential for the functional implementation of a micro-hydropower station in the design of a sprinkler machine to meet the in-system needs for electrical energy. Materials and methods: the study was carried out on the basis of an example of calculating the installation of a micro-hydropower station by A. G. Chernykh and the formulas presented in the handbook on hydraulics. To construct the multiple regression equation, the inverse matrix solution method was used. The calculation of the economic efficiency of the micro-hydropower station was carried out using the method of technical and economic analysis of possible options for electrification by S. G. Obukhov. Results and discussion: based on the results of the verification energy calculations, the effective power on the hydraulic turbine shaft with average technical parameters of low-pressure sprinkler machines was 1.202–15.648 kW. At the same time, linking the operation of the micro-hydropower plant to the irrigation systems of the North Caucasus territory has the potential to get 2596.32–33799.68 kW of generated electricity per year at a cost of 1 kW·h of 0.6204 rubles. Conclusions: the introduction of a micro-hydropower station in the design of sprinkler equipment will provide the ability to generate electricity within the available hydraulic characteristics. With this in mind, for the operation of hydropower equipment, it is necessary to have or create an additional water pressure. The multiple regression equation obtained on the basis of verification calculations of the parameters of the energy block of a microhydroelectric power plant showed that an increase in the water pressure per 1 m Н2О leads to an increase in effective power by an average of 0.611 kW.

The study was aimed at developing a new automatic search technique for specific invariant patterns associated with the execution of voluntary motor activity (Readiness potentials, RP) reflected in multidimensional electroencephalogram (EEG) signals. The Hausdorff metric was used as a criterion function for searching specific movement-related EEG patterns in brain activity. To increase the metric sensitivity, an adaptive low-pass filter was synthesized with the multivariate singular spectrum analysis (SSA). It has been experimentally demonstrated that significant temporal characteristics of the brain potentials preceding movement execution in the frontal, central and parietal areas of the cerebral cortex, on average, were 240±90 ms. It is shown that the synthesized adaptive filter has provided a reliable automatic search for induced pre-movement EEG patterns and the correct determination of their time boundaries (accuracy up to 96%). The developed method expands the existing tools to improve the functionality and reliability of various Brain-computer interfaces including those based on randomly generated, user-induced patterns of brain activity associated with voluntary motor activity.

An obesity is the topical problem worldwide, because excessive weight is the reason of metabolic changes that lead to development of serious chronic non-communicable diseases. The examination was aimed to assess clinical and metabolic health, nutritional status and behavior risk factors of obesity in people, working at the industrial plant. Material and methods. In 348 workers of the industrial plant (210 males, 138 females) examination was performed including anthropometry: body mass index (BMI), waist and hip circumferences and their ratio, blood pressure level detection, laboratory blood tests (glucose and cholesterol levels), and questionnaire on nutritional habits and physical activity. All examined were divided in three groups depending on BMI: 1st group - 151 (43.3%) persons with normal body mass, 2nd group - 125 (36%) working people with overweight and 3rd group - 72 (20.7%) people with obesity. Results. More than half of examined workers (mostly females) had overweight or obesity with predominantly abdominal type of fat distribution and I degree. Arterial hypertension was diagnosed in 41% of all working people (predominantly I degree), more frequently observed in obese (62.5%) and in males (45%). Each fourth man and woman had elevated total cholesterol level, which increased depending on BMI raise. Postprandial hyperglycemia was observed in 5.5% of cases, with the same frequency in both genders, predominantly in obesity. A significant part of responded with obesity, especially females, confirmed, that the reasons of excessive weight were stresses and somatic diseases (37%), and they preferred chocolate from confectionery. It was noted a correlation of BMI with egg consumption in males and with the consumption frequency of nuts, seeds and chocolate in females. Physical activity less than 3 times a month or never was observed in most of responded workers with overweight and obesity (73%), especially in males, as well as in females during the last month before the survey (57%). Conclusion. Preventive examination detected not only high prevalence of abdominal obesity, arterial hypertension and fat metabolism disturbances in people, working at the industrial plant, but also allowed to detect the most significant alimentary and behavioral risk factors of obesity.

Controlled growth of heterostructured nanowires and mechanisms of their formation have been actively studied during the last decades due to perspectives of their implementation. Here, we report on the self-catalyzed growth of axially heterostructured GaPN/GaP nanowires on Si(111) by plasma-assisted molecular beam epitaxy. Nanowire composition and structural properties were examined by means of Raman microspectroscopy and transmission electron microscopy. To study the optical properties of the synthesized nanoheterostructures, the nanowire array was embedded into the silicone rubber membrane and further released from the growth substrate. The reported approach allows us to study the nanowire optical properties avoiding the response from the parasitically grown island layer. Photoluminescence and Raman studies reveal different nitrogen content in nanowires and parasitic island layer. The effect is discussed in terms of the difference in vapor solid and vapor liquid solid growth mechanisms. Photoluminescence studies at low temperature (5K) demonstrate the transition to the quasi-direct gap in the nanowires typical for diluted nitrides with low N-content. The bright room temperature photoluminescent response demonstrates the potential application of nanowire/polymer matrix in flexible optoelectronic devices.

The polarization plane rotators located outside the volume of a transmission line are presented. Their work is based on the excitation of special ("dihedral") eigen-oscillations in a waveguide object formed by two grooved flanges with rotational symmetry. When one of the flanges rotates relative to the other, the composite object becomes 3D-chiral and rotates the plane of polarization by a certain angle in the band of several percent with minimal reverse loss. In circular and coaxial waveguides, mechanical or electronic tuning of the polarization plane is possible by mutual rotation of the flanges or by placing the controlled elements (media) into the object cavity.

Development of molecular beam epitaxy (MBE) of two-dimensional (2D) layered materials is an inevitable step in realizing novel devices based on 2D materials and heterostructures. However, due to existence of numerous polytypes and occurrence of additional phases, the synthesis of 2D films remains a difficult task. This paper reports on MBE growth of GaSe, InSe, and GaTe layers and related heterostructures on GaAs(001) substrates by using a Se valve cracking cell and group III metal effusion cells. The sophisticated self-consistent analysis of X-ray diffraction, transmission electron microscopy, and Raman spectroscopy data was used to establish the correlation between growth conditions, formed polytypes and additional phases, surface morphology and crystalline structure of the III&ndash, VI 2D layers. The photoluminescence and Raman spectra of the grown films are discussed in detail to confirm or correct the structural findings. The requirement of a high growth temperature for the fabrication of optically active 2D layers was confirmed for all materials. However, this also facilitated the strong diffusion of group III metals in III&ndash, VI and III&ndash, VI/II&ndash, VI heterostructures. In particular, the strong In diffusion into the underlying ZnSe layers was observed in ZnSe/InSe/ZnSe quantum well structures, and the Ga diffusion into the top InSe layer grown at ~450 &deg, C was confirmed by the Raman data in the InSe/GaSe heterostructures. The results on fabrication of the GaSe/GaTe quantum well structures are presented as well, although the choice of optimum growth temperatures to make them optically active is still a challenge.