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In this study, hydroxyapatite with the substitution of calcium cations by iron and phosphate by silicate groups was synthesized via a mechanochemical method. The as-prepared compounds have the general formula Ca10−xFex(PO4)6−x(SiO4)x(OH)2−xOx/2 with x = 0–1.5. The thermal stability of the as-prepared compounds was studied by ex situ annealing of powders in a furnace. It has been established that, at 800 °C for x ≤ 0.5, a partial decomposition of the substituted apatites occurs with the formation of the β–Ca3(PO4)2 phase. At high “x” values, the formation of this phase starts at the lower temperature of 700 °C, followed by the formation of Fe2O3 at 900 °C. The introduction of iron and silicate ions into the hydroxyapatite lattice was shown to decrease its thermal stability.

The article deals with the contemporary situation of gender and its implementation peculiarities in European countries. The article analyzes various approaches to the notion, gender disparity situation and reveals the burning challenges which the contemporary world faces now. The article highlights the present situation with gender asymmetry in STEM and ways of its transformation due to the unequal ratio of men and women employed in educational and scientific areas that would lead to employment problems in future. Much attention has been paid to the criterion for assessing gender equality, namely Gender Equality Index, an indicator that reflects the disparity in achievement opportunities between men and women in the European Union. Also, statistical data was presented that shows the great gender gap and identifies countries with a high / low gender equality index. Gender Equality Index is compared to the Global Gender Gap Index that shows the extent of the gender gap across four key dimensions that serve as a basis for developing effective measures to reduce the gender gap. The article points out the ways promoting the implementation of the principles of gender equality in European countries.

The wide spread of dermatological diseases is an important medical and social problem. Doctors note the constant growth of psoriasis among people of all ages. The psoriasis disease symptoms are similar to the symptoms of such diseases as eczema, atopic dermatitis and medicinal disease. Therefore, there is a high probability of an error in the disease diagnosis, which prevents the full treatment and prevention of the disease. Dermatological diagnostic systems are decision-making support systems for dermatologists when establishing a diagnosis and assessing the severity of the disease course. The development of new image processing methods for dermatological diagnostic systems is an important task, which allow to increase the accuracy of the diagnostic decision. In this work, the segmentation method of psoriasis images for systems of medical dermatological diagnostics based on a vector-difference approach to improve the quality of segmentation was developed. The vector-difference approach allows to calculate a certain texture feature of the image as a vector transformation of various texture features by linear algebra methods. Psoriasis disease images can be described by texture (spectral, statistical, spectral-statistical) and color, so it is proposed to take into account textural and color characteristics of images for image segmentation. The color models that are most often used in segmentation methods of psoriasis disease images were analyzed. Based on the analysis, the Hue-Saturation-Intensity color model was chosen.It is proposed to use spectral, statistical and spectral-statistical texture models and color characteristics of image pixels to represent psoriasis disease images. The developed segmentation method includes the following stages: image pre-processing; identification; vector-difference transformation; threshold processing. At the pre-processing stage, homomorphic filtering was applied to psoriasis disease images. The result of the identification stage is a set of features calculated by the textural and color characteristics for image objects. The vector-difference transformation converts the texture image into intensity. Threshold processing is performed with a global threshold. Experimental research of the proposed segmentation method of psoriasis disease images was performed. As a result of the experimental research, it was found that the probability of correct identification of psoriasis disease area on average is 0.97, the probability of a false alarm is about 0.05.

On the basis of the norms of administrative law and current legislation analysis, the preventive activities of the National Police on juvenile prevention were investigated. Consideration of the specified problems within the scope of the article allows to expand the traditional approach to juvenile prevention, not only to connect the issue of prevention of offenses with the prevention of criminal offenses among children, but also to develop measures aimed at preventing administrative offenses committed by this category of persons, as well as the implementation of activities, related to the protection of children’s rights. For this purpose, the role of the National Police units for juvenile prevention in the prevention and counteraction of criminal and administrative offenses through the prism of the main tasks that rely on the latter was clarified and disclosed, and measures aimed at improving preventive and prophylactic work to ensure the rights and legitimate interests of children were also highlighted. It has been found that in the context of the formation of the National Police and the creation of a body aimed at providing high-quality police services to the population, juvenile prevention units direct their efforts to ensure and protect the rights of children. It has been proven that the preventive activity of the National Police on juvenile prevention is regulated by the norms of administrative law, the activity of juvenile prevention units, the content of which is preventive and prophylactic work to ensure the rights and legitimate interests of children, prevent children from committing criminal and administrative offenses, identify the causes and conditions that this is facilitated by taking measures to eliminate them, as well as implementing the norms of current legislation in terms of preventing and countering domestic violence committed by and in relation to children, preventing child neglect and carrying out pre-trial investigation of criminal offenses in the form of an inquiry within the scope of competence.

Apatite is widely used in medicine as a biomaterial for bone tissue restoration. Properties of apatite depend on its composition, including the Ca/P ratio. This paper shows what range of Ca/P ratio can be attained in apatite by the mechanochemical method of synthesis, providing fast formation of a single-phase product. The synthesis was carried out from a reaction mixture of CaHPO4 and CaO at different Ca/P ratios in the range of 1.17–2.10. The products were studied by PXRD, FTIR and NMR spectroscopy, HRTEM, and STA. In mixtures with a low initial Ca/P ratio (1.17–1.48), directly in the mill, the formation of calcium orthophosphate with whitlockite structure containing an HPO42− group and structural water is shown for the first time. This phosphate has structure similar to that of whitlockites of hydrothermal origin and differs from high-temperature β-tricalcium phosphate that has composition Ca3(PO4)3. A series of samples of apatite was obtained with varied composition, which depends on the initial Ca/P ratio. At Ca/P < 1.67, the formation of two types of calcium-deficient apatite was documented. At Ca/P > 1.67, the existence of two types of calcium-rich apatite is confirmed.

In this paper, room-temperature chemiresistive gas sensors for NO2 detection based on CVD-grown carbon nanofibers (CNFs) were investigated. Transmission electron microscopy, low-temperature nitrogen adsorption, and X-ray diffraction were used to investigate the carbon nanomaterials. CNFs were synthesized in a wide range of pressure (1–5 bar) by COx-free decomposition of methane over the Ni/Al2O3 catalyst. It was found that the increase in pressure during the synthesis of CNFs induced the later deactivation of the catalyst, and the yield of CNFs decreased when increasing pressure. Sensing properties were determined in a dynamic flow-through installation at NO2 concentrations ranging from 1 to 400 ppm. Ammonia detection was tested for comparison in a range of 100–500 ppm. The obtained sensors based on CNFs synthesized at 1 bar showed high responses of 1.7%, 5.0%, and 10.0% to 1 ppm, 5 ppm, and 10 ppm NO2 at 25 ± 2 °C, respectively. It was shown that the obtained non-modified carbon nanomaterials can be used successfully used for room temperature detection of nitrogen dioxide. It was found that the increase in relative humidity (RH) of air induced growth of response, and this effect was facilitated after reaching RH ~35% for CNFs synthesized at elevated pressures.

Gd3+ and Sm3+ co-activation, the effect of cation substitutions and the creation of cation vacancies in the scheelite-type framework are investigated as factors influencing luminescence properties. AgxGd((2−x)/3)−0.3−ySmyEu3+0.3☐(1−2x)/3WO4 (x = 0.50, 0.286, 0.20; y = 0.01, 0.02, 0.03, 0.3) scheelite-type phases (AxGSyE) have been synthesized by a solid-state method. A powder X-ray diffraction study of AxGSyE (x = 0.286, 0.2; y = 0.01, 0.02, 0.03) shows that the crystal structures have an incommensurately modulated character similar to other cation-deficient scheelite-related phases. Luminescence properties have been evaluated under near-ultraviolet (n–UV) light. The photoluminescence excitation spectra of AxGSyE demonstrate the strongest absorption at 395 nm, which matches well with commercially available UV-emitting GaN-based LED chips. Gd3+ and Sm3+ co-activation leads to a notable decreasing intensity of the charge transfer band in comparison with Gd3+ single-doped phases. The main absorption is the 7F0 → 5L6 transition of Eu3+ at 395 nm and the 6H5/2 → 4F7/2 transition of Sm3+ at 405 nm. The photoluminescence emission spectra of all the samples indicate intense red emission due to the 5D0 → 7F2 transition of Eu3+. The intensity of the 5D0 → 7F2 emission increases from ~2 times (x = 0.2, y = 0.01 and x = 0.286, y = 0.02) to ~4 times (x = 0.5, y = 0.01) in the Gd3+ and Sm3+ co-doped samples. The integral emission intensity of Ag0.20Gd0.29Sm0.01Eu0.30WO4 in the red visible spectral range (the 5D0 → 7F2 transition) is higher by ~20% than that of the commercially used red phosphor of Gd2O2S:Eu3+. A thermal quenching study of the luminescence of the Eu3+ emission reveals the influence of the structure of compounds and the Sm3+ concentration on the temperature dependence and behavior of the synthesized crystals. Ag0.286Gd0.252Sm0.02Eu0.30WO4 and Ag0.20Gd0.29Sm0.01Eu0.30WO4, with the incommensurately modulated (3 + 1)D monoclinic structure, are very attractive as near-UV converting phosphors applied as red-emitting phosphors for LEDs.

Background: At present, the problem of treating common forms of colorectal cancer does not lose its relevance due to the increase in its incidence. Systemic chemotherapy is the main line of treatment for patients with unresectable liver metastases. However, a significant problem of modern oncology is the further treatment tactics for patients with chemoresistant metastases. Aims: to improve the treatment results for patients with chemoresistant liver metastases of colorectal cancer. Method: 36 patients with unresectable liver metastases of colorectal cancer were treated at the Granov Russian Research Center of Radiology and Surgical Technologies and the RZD-Medicine Central Clinical Hospital. For all the patients, systemic chemotherapy was considered unreasonable due to the development of chemoresistance or a high degree of toxicity. The patients underwent regional chemotherapy chemoinfusion and/or chemoembolization of the hepatic artery. Results: The treatment evaluation was performed using the RECIST 1.1 scale. After 6 months, a partial response was reached in 1 patient (2.8%), stabilization was observed in 29 (80.5%) patients, and 6 patients (16.7%) had the disease progression. In 2 (5.6%) cases, a lethal outcome was observed against the background of the systemic progression of the oncological disease. One year later, stabilization of the malignant process was detected in 21 (58.3%) cases, progression was detected in 15 (41.7%) cases. A one-year survival of patients was 83.3%, the overall survival 22 months. Conclusion: The use of interventional radiology methods has shown its effectiveness in patients with unresectable chemoresistant liver metastases of colorectal cancer.

The article deals with the contemporary situation in education sphere in Ukraine, describing the main aspects of STEM implementation. The article analyzes the main aspects of a learning strategy STEM which provides students mainly with an interdisciplinary approach to learning. Both the advantageous and disadvantageous issues of this learning approach are revealed in the article. The peculiarities of STEAM learning method in Ukraine have also been emphasized. In the course of the study, it has been discovered that modern educational system faces lots of challenges and needs to be improved by implementing an interdisciplinary approach to learning such as STEM education that promote not only skills such as critical thinking, problem solving, higher-order thinking, but also behavioral competencies such as adaptability, cooperation, organization, and responsibility. Examples of the implementation of STEM-education in the scientific and pedagogical project "Scientific and methodological foundations for creating an innovative model of STEM education" are presented. Despite the fact that Ukrainian schools are just beginning to prepare for work on the principles of STEM, some typical features of the introduction of STEM education, which is new to us, are already obvious. Significant shortcomings are, among other reasons, an insufficient number of teachers willing to work in a new way, and an insufficient material and technical base. These two aspects partially hinder the introduction of STEM-direction, based on the integration of knowledge, attraction of resources, cooperation of skills.

The paper presents a project for the adaptation of graduates of pedagogical universities to work at educational organizations. The goal and tasks of the project, the organizational plan, and specific steps for its implementation are specified. The authors analyze possible risks, results, and prospects for the development of the project and briefly outline the legal and financial plans and the strategy of the project. The project implies close interaction of young teachers with the school administration, experienced teachers, students, and their parents, as well as improvement of professional culture and competencies in educational activities. The objective of the study is to design a set of organizational and pedagogical measures to ensure the successful social and professional adaptation of a young teacher. Methodology: the methodology of the work was based on the activity approach and the principle of systematicity; it also included a theoretical study of empirical data obtained by observation and diagnostics. Results: the development of a program for the adaptation of young teachers in general education schools is an efficient way to overcome difficulties in novice teachers’ professional activities. The professional development of a young teacher will be more successful if the interaction of teachers, students, and their parents is actively and correctly implemented. This becomes possible due to diagnostics of pedagogical difficulties and professional competence; involving experienced teachers performing the mentoring function in the adaptation of young teachers; transforming adaptation into a management process. The authors prepared organizational step-by-step training including: 1. conducting classes of the “School of Pedagogical Experience”, communicative training sessions, workshops on planning and conducting classes and extracurricular activities for young teachers, assigning a teacher-mentor, social care teacher, and psychologist for each young specialist; 2. intensifying the participation of young professionals in creative groups, public teams, professional competitions; novice teachers’ self-analysis of their pedagogical activity at the end of the academic year and revealing further areas for self-improvement; 3. various forms of events (consultations, open classes, master classes, workshops, creating a portfolio, a professional skill competition, etc.) to improve young teachers’ professional competence; diagnosing young specialists’ professional qualities and preparing them for job competence certification. Multifaceted activities, especially methodological ones, for the adaptation of young specialists will help to improve their professional competence and solve the personnel problem of schools. Practical implications: the developed project can be used as a launching platform for the adaptation of young teachers at not only general education organizations but also educational organizations of other education types and levels. The project implies network cooperation with other educational institutions, conducting joint methodological activities, and involving experienced schoolteachers in organizing young teachers’ work at school.

In this study, the mechanochemical synthesis of substituted hydroxyapatite (HA) containing zinc and silicon ions having a chemical formula of Ca10−xZnx(PO4)6−x(SiO4)x(OH)2−x, where x = 0.2, 0.6, 1.0, 1.5, and 2.0, was carried out. The synthesized materials were characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, and inductively coupled plasma spectroscopy. We found that HA co-substituted with zinc and silicate formed up to x = 1.0. At higher concentrations of the substituents, the formation of large amounts of an amorphous phase was observed. The cytotoxicity and biocompatibility of the co-substituted HA was studied in vitro on Hek293 and MG-63 cell lines. The HA co-substituted with zinc and silicate demonstrated high biocompatibility; the lowest cytotoxicity was observed at x = 0.2. For this composition, good proliferation of MG-63 osteoblast-like cells and an increased solubility compared with that of HA were detected. These properties allow us to recommend the synthesized material for medical applications, namely, for the restoration of bone tissue and manufacture of biodegradable implants.

Fast diffusion along grain boundaries and slow diffusion within grains’ bulk were revealed for Nd tungstates. A significant decrease in diffusivity was shown for their composites as the reduction + reoxidation led to an increase in oxygen mobility.

The article examines the tasks of the National Police of Ukraine as a subject of implementation of the preventive function of the state. It is emphasized that the tasks of the Department of Preventive Activities of the National Police of Ukraine are an important component of determining the specifics of its activities and administrative and legal status, as the effective implementation of the Department of Preventive Activities of the National Police of Ukraine depends on a clear legislative understanding of its tasks as body of state power. It is noted that the implementation of the tasks of the National Police in Ukraine means that policing is based on the principles enshrined in current legislation, taking into account current trends in European integration. The principles as guiding ideas that underlie the functioning of each police body and unit are designed to promote the further development of the police as a European-style institution. In turn, the tasks of the police determine the means of policing, based on the relevant principles. It is emphasized that the main tasks of the Department of Preventive Activities of the National Police of Ukraine are to organize and ensure within the competence of the National Police of Ukraine the functions of Ukrainian legislation to maintain public safety and order, protect human rights and freedoms, and individual preventive work aimed at preventing the commission of administrative and criminal offenses, preventing and combating domestic violence, escorting persons detained on suspicion of committing a criminal offense, taken into custody, accused, sentenced to arrest or imprisonment, and for a term of imprisonment in the courtroom. It was emphasized that the general tasks of the Department of Preventive Activities of the National Police of Ukraine include: ensuring public safety and public order; protection of fundamental human rights and freedoms, as well as the interests of society and the state; providing, within the limits established by law, services to assist persons who, for personal, economic, social reasons or due to emergencies, need such assistance. It is noted that the special tasks of the Department of Preventive Activities of the National Police of Ukraine include: implementation of state policy in the field of combating violence; preventive measures; introduction of programme preventive means for systematization of violent incidents, general and individual preventive work aimed at preventing the commission of administrative and criminal offenses, prevention and counteraction to domestic violence.

The legal and ethical regulation of medical activity in Russia vs. European countries has common features and a number of specific differences. The regulation of medical activity in the Old Russian state and European medieval states was carried out within the framework of legal norms and Christian worldview, the main principle of which was service to one’s neighbor. For instance, these were ethical issues that came to the fore. The secular state form, began its historical path with the emergence of the first secular doctors at the courts of ancient Russian princes. From the 16th century on, it became part of the state apparatus extending its influence to the social estate of the military servicemen. In the middle of the 19th century, during the period of the Zemstvo Reform, it became the main form of servicing rural population. The specificity of zemstvo medicine was the organization of medical activities based on of local self-government bodies and medical societies. At the beginning of the 19th century, with the increasing complexity of scientific knowledge and organization of medical services, European medical codes of ethics aimed at developing the rules of conduct to be followed by the members of newly emerging national medical associations. Despite regulating medical activity, the issues of healthcare were not given due attention, and there were no specific legislative acts affecting the health care regulation in prerevolutionary Russia. In Europe, too, for a long time, the responsibility of a medical professional for mistakes was considered from the standpoint of private relationships based on contractual and commercial principles.

A comparison is made of the thermoanalytical characteristics and the composition and structure of solid products of the thermal decomposition of ortho-phthalates [Cu(H2O)2(C8H4O4)], [CuNi(H2O)4(C8H4O4)2], and [Ni(H2O)2(C8H4O4)](H2O)2. It is found that the thermal decomposition of these compounds upon heating to 500°C in a He atmosphere can be conditionally divided into two stages: dehydration and decarboxylation. Polymer conglomerates containing uncoated Cu nanoparticles as large as 75 nm are embedded into the polymer matrix of the composite obtained via the thermal decomposition of [Cu(H2O)2(C8H4O4)]. Three types of nanoparticles with sizes of 40–85, 15–25, and 10–15 nm are embedded in the polymer matrices of composites. The particles are Cux/Ni1−x solid solutions of different compositions, obtained via the thermolysis of [CuNi(H2O)4(C8H4O4)2]. It is found that the onset temperature of [CuNi(H2O)4(C8H4O4)2] decarboxylation at the third part of the second stage with the formation of a three-phase region correlates with the temperature of decomposition of Cux/Ni1 – x solid solutions in the binary metal system, due apparently to the quantum size effect.

A series of Al2O3 nanoparticles with the sizes ranging from ~ 2 to 21 nm, according to XRD, HRTEM and BET, was obtained by vaporization of α-Al2O3 in flowing helium and argon at different pressures under the action of a cw CO2 laser. The particle size was changed by varying the composition of ambient gas (He, Ar) and its pressure in a vaporization chamber from 0.034 to 0.9 bar. The effect of the synthesis conditions on the properties of Al2O3 nanopowders is presented and discussed. Particles with the size smaller than 6–7 nm have a faceted shape, whereas the shape of larger particles is close to spherical. It was found that the resulting nanopowders consist of a mixture of transition aluminas, among which the γ-polymorph is dominant. Thermal analysis showed that for smaller nanoparticles the phase transition to α-Al2O3 occurs at a lower temperature. In nominally pure Al2O3 nanoparticles with different sizes, photoluminescence at RT and 80 K is determined by trace level concentrations (≤10–3 wt%) of uncontrolled impurities of 3d elements (Cr3+(Oh) and Fe3+(Td)), surface hydroxyl groups, and point defects represented mostly by F-type centers. The acquired experimental data indicate that manifestation of the size effect for Al2O3 nanoparticles has a boundary corresponding to 6–7 nm. Al2O3 nanoparticles with the dominant γ-Al2O3 structure obtained by the laser method can be promising in many chemical reactions, particularly as the supports of catalysts and sorbents, for which the high specific surface area is of special importance.

Samples of YAG : Се optical ceramics with an activator concentration of 0.5, 1, 5, and 10 at. % were synthesized by a solid-phase method. The synthesis of the samples containing 10 at. % Ce was accompanied by a significant decrease in the weight (to 11.69 wt %) and an anomalous growth of crystallites more than 2 mm in size. The effect of the type of the sintering additive and the activator concentration on the physicochemical properties of the YAG : Ce ceramics was determined. The use of silica as a sintering additive was found to require higher temperatures for the synthesis of the ceramics than the use of zirconia. The activator (cerium) in YAG was observed to behave as a sintering additive, accelerating mass-transfer processes. The luminescence properties of the synthesized samples excited by pulsed and stationary X-ray sources were studied. The relationships between the emissions of Ce3+ and YAl antisite defects, and between the timing performance and the concentration quenching were considered. The ceramic sample with a cerium concentration of 0.5 at. % demonstrated the maximum intensity of the Ce3+ emission band, and the sample containing 10 at. % showed the fastest luminescence response (67 ns).

Modern world languages, with their specific features of sound, grammar and vocabulary, emerge as a product of long historical development, in the process of which they have undergone various changes due to various reasons. In most cases, under the internal laws of development, the greatest changes can be traced in the field of vocabulary, under the influence of external factors related to the historical destiny of the people, the native language speakers. Changes can affect all the aspects of language structure, but they work differently. The process of borrowing words is natural and inevitable, due to trade, scientific and cultural contacts between peoples. Every closed national culture usually loses in its development. However, this process proceeds with varying degrees of intensity. Language cannot exist outside the context of a languagecentered culture. Unlike Slavic, Germanic and Romance languages, Chinese as a donor language does not play a significant role in replenishing the vocabulary of European languages. Recently, one source language has been actively used, it is English. Nevertheless, there are a number of borrowings from the Chinese language, which are several thematic groups, and their composition has been replenished. Their study is currently particularly relevant in connection with the processes of globalization. The article attempts to analyze the impact of the Chinese language and culture on the European society in general and English in particular. How do language and culture relate - these two most important attributes of a person and humanity? How do they interact? These are the basis of most cultural formations and communicative reality; they are all complex and very topical questions that the research is to answer.

In recent years, demand for scintillation detectors with high time resolution (better than 100 ps) has emerged in high-energy physics and medical imaging applications. In particular, time of flight positron emission tomography (TOF-PET) can greatly benefit from increasing time resolution of scintillators, which leads to the increase of signal-to-noise ratio, decrease of patient dose, and achievement of the superior spatial resolution of PET images. Currently, extensive research of various types of materials is carried out to achieve the best time resolution. In this review, the recent progress of various approaches is summarized and scintillation compounds with the best temporal characteristics are first reviewed. The review presents the physical processes causing fast luminescence in inorganic and organic materials. Special attention is paid to nanocomposites which belong to a new perspective class of scintillating materials, consisting of a plastic matrix, inorganic nanocrystalline fillers, and organic or inorganic luminescence activators and shifters. The main features and functions of all parts of existing and prospective nanocomposite scintillators are also discussed. A number of currently created and investigated nanocomposite materials with various compounds and structures are reviewed.

Observations at permanent stations of the Global Navigation Satellite System (GNSS) are directly related to global and local movements of the Earth’s crust and are also affected by various factors, such as the multipath effect and radio noise in the signal. Currently, the influence of such effects can be analyzed and excluded from further processing of GNSS observations. However, there are a number of GNSS stations that deserve more attention for the monitoring of operational stability, because they define the terrestrial implementation of the reference system. The Chernihiv station (CNIV, DOMES 15501M001), which is attributed to the class A for the definition of the European Reference Frame, is an example of such a GNSS station in the territory of Ukraine. In this article, the coordinate time series based on long continuous coordinate time series and the log file of the GNSS station Chernihiv is analyzed. The coordinates of the station during the operation of various equipment are compared, and conclusions about the stability of the station are made. It was found that the station has been working stably and has not had long interruptions in observations since its commissioning. The most significant changes that occurred at the station are associated with the change of equipment. The equipment at the station was changed three times: Trimble equipment was installed in 2005, it was replaced by NovAtel equipment in 2011, and Leica equipment was installed in 2013, which is still in operation. Analysis of the time series of this permanent station shows that there is a certain jump in the study of changes in coordinates simultaneous for all devices when the Leica equipment was installed, which is associated with the change of equipment, namely with a different system of mounting the antenna on the pole. However, in the study of coordinate residuals separately for each equipment, fluctuations in values in winter and summer are observed, which can be related to the structural deformation of the GNSS antenna.

Ethanol steam reforming catalyst’s precursors, i.e., nanocomposites of complex oxides with the general formula [Pr0.15Sm0.15Ce0.35Zr0.35O2 + LaMn0.45Ni0.45Ru0.1O3] (1:1 by mass), were synthesized by three different methods. It was shown that two synthesis methods – ultrasonic dispersion and sequential polymeric method, lead to the formation of the nanocomposite perovskite–fluorite system with the specific surface area up to 50 m2/g. Reduction of samples at 400–500°C lead to the formation of Ni–Ru alloy nanoparticles strongly bound with the surface of oxide nanocomposite. Catalytic tests in ethanol steam reforming reaction at 500–600°C showed the highest specific activity of the sample prepared by the sequential polymeric method due to the location of Ni- and Ru-containing perovskite mainly on the surface of the composite providing a high concentration of active metal centers. At higher temperatures for all samples, ethanol conversion approached 100% with hydrogen yield varying in the range of 65–75%. A study of spent catalysts confirmed the absence of carbon deposits after long-term catalytic tests at 650°C.

Composites comprising MoVTeNbO mixed oxide and zirconia-pillared montmorillonite clays (PilCs) were prepared. XRD and TEM with EDX studies confirmed the preservation of M1 MoVTeNbO phase in these composites responsible for high activity and selectivity in ethane oxidative dehydrogenation into ethylene. For composites with PilC content of 10 wt%, the best ethylene yield exceeding that of bulk MoVTeNbO oxide was demonstrated for clays with zirconia pillars doped with Ce and Al possessing the highest specific surface area. This is explained by optimized chemical interaction of these clays with MoVTeNbO mixed oxide improving its bulk oxygen mobility and reactivity by structure disordering while blocking surface sites responsible for combustion due to the stabilization of the reactive terminal oxygen species.

Approaches to the synthesis of isocoumarins and 3,4-dihydroisocoumarins containing natural or synthetic amino-acid fragments are reviewed. Most attention is paid to the two most numerous groups of natural 3,4-dihydroisocoumarins, i.e., ochratoxins and amicoumacins.

The current state of the research activities of the Main Astronomical Observatory of the National Academy of Sciences of Ukraine (MAO NASU) on the use of GNSS technology is presented. Today, MAO operates a permanent GNSS network consisting of five stations (two stations are temporarily inactive). All stations are included in EPN and the EPOS network, GLSV, KHAR, and UZHL stations are also integrated to the IGS network. MAO Operational Centre also provides automatic data transfer from 12 stations installed by other Ukrainian organizations included in the international networks. Data from approximately 300 Ukrainian permanent GNSS stations are stored in the MAO Local Data Centre. The MAO Local Analysis Centre uses Bernese GNSS Software for different types of data processing of GNSS observations. Rapid processing is performed on a daily basis for monitoring the stability of the permanent stations from some Ukrainian RTK networks. All available observations data from the Ukrainian stations for the period from December 7, 1997, to January 28, 2017, were processed according EPN standards during the MAO’s second reprocessing campaign and regular processing. As a result, the coordinates in the IGb08 reference frame and tropospheric zenith delays for 233 permanent stations (202 of them are the Ukrainian stations), as well as the velocities for the 128 stations that have observation period more than 3 years, were estimated. The creation and development of local GNSS networks, as well as the long-term filling of databases with high-precision coordinate solutions and estimates of the displacement velocities of GNSS stations, made possible to conduct geodynamic studies at the local level. The strain ellipses and rotation were found based on estimated coordinates and velocities of the GNSS stations. In 2016–2019, Kharkiv National University of Radio Electronics, in cooperation with MAO NASU, performed a number of studies on high-precision GNSS positioning and navigation. New implementations of modern methods and algorithms for the PPP positioning were created and experimentally tested. The errors of the daily floating PPP solutions were 5…8 mm (with a probability of P ≈ 95%) for static mode and 5…8 cm (P ≈ 68%) for kinematic mode. The decimeter/centimeter error of determining the coordinates of current satellites with low Earth orbits (LEO) in the implementation of kinematic floating and fixed PPP solutions was proven. The development of a high-accuracy multiposition phase system of trajectory measurements for field tests of high dynamic aircrafts (HDA) were proposed. The estimated values of the root-mean-square error (RMSE) in determining the HDA motion variables were in the range from 0.05 to 0.40 m for coordinates and from 0.5 to 1.6 cm/s for the velocity vector components.

Purpose of the study. To analyze the causes of unsatisfactory results after laparoscopic repair of hiatal hernia, complicated by gastroesophageal reflux disease. Materials and methods. A retrospective analysis of the treatment of 171 patients, who underwent laparoscopic hiatal hernia repair for the period 2009–2018 was carried out. In case of hiatal hernia defect 5 or more cm 29 (29.6%) of 98 patients performed the mesh hiatal hernia repair. Nissen fundoplication was used in 109 (63.7%) patients, Toupet fundoplication – in 62 (36.3%) patients. Intra‑abdominal esophagus segment length was measured intraoperatively after mediastinal mobilization, and after desuflation before the creation of the fundoplication wrap. In the long‑term postoperative period in patients, who did not have complaints the length of fundoplication wrap was measured. The causes of reoperations were analyzed. Results. In the long‑term period, recurrence was noted in 34 (19.9%) patients, persistent dysphagia was noted in 10 (5.8%) patients, the overall unsatisfactory result was 22.8% (39 patients). 26 (15.2%) patients were unsatisfied their present condition (according to the GERD‑HRQL questionnaire). The use of mesh repair in comparison with simple suture repair not affected on frequency of recurrence in case of hernia 5 cm or more – 4 (13.8%) versus 14 (20.3%), CI: 0.19–2.1, p=0.44. The choice of fundoplication method (Nissen or Toupet) not affected on recurrence rate – 17.4% (19/109) versus 24.2% (15/62), CI: 0.71–3.24, p=0.39. The length of the fundoplication wrap at uppercontrastradiographswas 3.2 cm (2.3–3.7 cm). Intraoperativly after desuflation, the shortening of the esophagus was 1.3 cm (0.5–2 cm). 12 (7%) patients were reoperated. The shortening of the esophagus was revealed in all cases of reoperations. Conclusion. Unreduced during the first operation short esophagus, which was diagnosed during all reoperations, was one of the possible factors, affecting the frequency of recurrence in the long term. Further studies are needed to evaluate the use of lengthening esophagus procedure on the long-term outcomes.

The doping of hydroxyapatite with various substituent ions can give this material new and useful properties. Nonetheless, local distortions of structure after doping can change the properties of the material. In this work, the thermal stability of copper-substituted hydroxyapatite synthesized by the mechanochemical method was investigated. In situ diffraction analyses showed that copper ion diffusion during the heating of Cu-substituted hydroxyapatite promotes phase transformations in the substituted hydroxyapatite. The behavior of copper ions was studied in samples with ratios (Ca + Cu)/P = 1.75 and 1.67. It was found that in both cases, single-phase Cu-substituted hydroxyapatite with the general formula Ca10−xCux(PO4)6−y(CO3)y(OH)2−yOy is formed by the mechanochemical synthesis. When heated at approximately 600–700 °C, the lattice loses copper cations, but at higher temperatures, CuO diffusion into the hydroxyl channel takes place. Cuprate-substituted hydroxyapatite with the general formula Ca10(PO4)6(OH)2−2x(CuO2)x forms in this context. At 1200 °C, the sample is single-phase at (Ca + Cu)/P = 1.75. Nonetheless, slow cooling of the material leads to the emergence of a CuO phase, as in the case of (Ca + Cu)/P = 1.67, where the material contains not only CuO but also Cu-substituted tricalcium phosphate. In the manufacture of ceramic products from Cu-substituted hydroxyapatite, these structural transformations must be taken into account, as they alter not only thermal but also biological properties of such materials.

Eu-doped bismuth-based Bi

A task-specific ionic liquid (IL) is employed as a structure directing agent for the synthesis of quantum cutting BaGdF5:Eu3+ nanophosphors. Herein, IL and temperature dependent quantum cutting is observed. Maximum (160%) and minimum (123%) quantum cutting efficiencies (QCEs) are obtained in the presence and absence of IL, respectively, at room temperature (295 K). However, at low temperature (10 K), the emission spectrum is dominated by Eu2+ 5d–4f emission which is further confirmed by X-ray excited luminescence study. It is also observed that decay kinetics recorded for Eu2+ 5d–4f emission demonstrate longer (with lifetime from 580 ns to 1.5 μs) and faster (with lifetime from 35 to 50 ns) decay components related to normal and surface quenched emission, respectively. In addition, maximum quantum yield (η = 73.5%) is obtained for the sample prepared in the presence of IL compared to that for the sample prepared without IL (η = 65%). The easy yet highly phase selective green synthesis of the materials is promising for large scale industrial application in nanothermometry as well as in environmentally benign energy efficient lighting.

Some results on the mechanochemical synthesis of apatites with simultaneous substitutions of calcium by lanthanum and of phosphate by silicate are presented. The reagents of reaction mixtures are taken such that to synthesize the compounds containing equal concentrations of lanthanum and silicon. The synthesis is performed in an AGO-2 planetary mill. The complete conversion of initial reagents in the synthesis of substituted apatite takes a longer period as compared to the time required for the synthesis of unsubstituted apatite. The mechanochemical synthesis time must be 40 min to synthesize lanthanum-and-silicate substituted apatite with a degree of substitution of