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Subject and Purpose. Results are presented of the solar corona investigations performed with the world famous Ukrainian radio telescopes. The work has been aimed at offering a consistent review of recent achievements in observations of a variety of low-frequency radio emissions from the Sun. Methods and Methodology. The studies of the quiet (thermal) and sporadic (burst-like) radio emissions from the Sun have been carried out with the decameter-wavelength radio telescopes UTR-2, GURT and URAN-2. Specific features of the low-frequency solar radio emissions from a variety of sources are presented, with characterization of the optimized techniques that were applied in each case for evaluating physical parameters of the corona in the areas of decameter-wavelength radio wave generation. Results. The analysis of temporal, frequency and spatial characteristics of solar radio emissions has allowed suggesting a number of models for the coronal electron density distribution, and evaluating magnetic field strengths in the corona. Also, our experimental results have proven to be consistent with the observational data obtained in different frequency ranges and with the use of both ground based and space-borne instruments. Conclusions. The radio observations performed with Ukrainian radio telescopes have permitted studying, with high temporal, frequency and spatial resolutions, solar radio frequency emissions from various localized sources. Along with the large effective area and high sensitivity of the antennas, this permits application of a wide range of methods and tools aimed at detecting and analyzing solar bursts, of both strong and weak intensity, against the background of terrestrial interference of natural or artificial origin.

In this work, four waste paper composites were studied in terms of several photon interaction parameters over the energy region from 0.015 to 15.0 MeV. The waste paper and natural rubber (WP/NR) composites of different densities ranging from ρ = 0.894 to 1.16 gm⋅cm-3 were used for shielding radioactive rubble at different time period stages. Some additives were also used including high-abrasion furnace black, paraffin wax, B4C, as well as magnetite. The deduced parameters of photon interaction: equivalent atomic number Zeq, exposure buildup factor and energy absorption buildup factor have been studied as a function of incident photon energy, WP/NR elemental composition, and for penetration depths, up to 40 mean free path. The Zeq numbers have shown slight variation over the selected incident energy range and buildup factors were found to be modest at low and high photon energy meanwhile their values increase widely over the intermediate energy region. In addition, kerma relative to air for photon energies from 1 to 20 MeV were computed and show dependence upon equivalent atomic numbers. In this work, it was clear that filled samples offer better shielding capabilities than unfilled ones. The obtained data could be useful for radiation physicists and scientists in estimating the γ-irradiation received after applying such shields.

Purpose. To substantiate the breakdown mechanism of capacitor paper on the basis of numerical-field models with segmented cross-sections of cylindrical volumes of air and water, and also use the proposed models to determine the breakdown strength of air in micron-sized gaps under normal conditions. Methodology. The model bases on a finite element solution to an electrostatic problem in a volume of capacitor paper consisting of cellulose and pores with air and water. First, the possible scenarios for the growth of breakdown in capacitor paper are analyzed and to the conclusion is made, that complete breakdown developed from a partial breakdown in the air cavity. A brand of capacitor paper is chosen in such a way that when its thickness changed, the breakdown strength of the electric field changed over a wide range. Then, for the paper with the lowest average electric field intensity the possibility of explaining the complete breakdown by the breakdown of air segments on the basis of the Paschen dependence is checked. Further points of the obtained dependence by constructing models of papers of the same brand and a different thickness under the assumption of the similarity of electrostatic fields are determined. As such a criterion, the constancy of the equivalent effective permittivity are taken. Results. The dependence of the breakdown strength of the air in the range of 1.36...5.54 μm under normal conditions is determined. The obtained relationship is between the Peschot and Taev curves. Originality. For the first time, the possibility of indirectly estimation the breakdown strength of an insulating material using an electrostatic field model is indicated. Practical value. The proposed method for the numerical calculation of the breakdown voltage of air inclusions in the presence of water inclusions in the thickness of solid insulation can be applied to other types of solid thin-layer insulation.

Background. The development of technologies for obtaining materials from plant raw materials, the use of which improves the consumer properties of cardboard and paper products and does not pollute the environment with harmful substances from synthetic polymers, is an urgent problem of our time. Objective. The purpose of the paper is to obtain pulp and nanocellulose from reed stalks by environmentally friendly methods and apply nanocellulose to improve the quality parameters of paper for packaging food products on automatic machines. Methods. To obtain pulp from reed stalks with a minimum residual content of lignin and minerals, two processing stages were used: alkaline extraction and organosolv cooking at a temperature of 97 ± 2 °C. Nanocellulose was obtained by the oxidation of organosolv reed pulp with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) in the TEMPO / NaBr / NaClO system, which is more environmentally friendly than acid hydrolysis. The resulting nanocellulose was applied to paper samples from waste paper and sulphate unbleached pulp at a consumption from 1 to 3 g/m2. Results. Organosolv pulp was obtained from reed stalks with a residual lignin content of 0.53 % and an ash content of 0.045 %, which was used to obtain nanocellulose. The resulting nanocellulose particles have a transverse size in the range of 5–20 nm, a length of up to several micrometers, and the tensile strength of nanocellulose films is up to 60 MPa. It is shown that the application of nanocellulose to the surface of the samples increases the breaking strength and breaking length, and reduces the surface absorbency of paper. It was determined that with a nanocellulose consumption of up to 3 g/m2, paper samples have indicators that meet the requirements of the standard for paper for packaging food products on automatic machines. Conclusions. The use of nanocellulose from reed stalks as a hardening substance for paper production will allow replacing environmentally harmful polymer additives and up to 50 % of more expensive softwood pulp with waste paper, while maintaining paper quality indicators at the level of standard requirements.

In recent years, concrete in the construction industry has rapidly increased worldwide, including developing countries like India. The raw materials required to produce such a quantity require huge depletion of natural resources. On the other hand, disposal of paper waste, fly ash, and plastic waste is one of the biggest problems faced by many countries, including India, the amount of waste collected and recycled is less compared to disposal quantity. The use of these wastes in concrete reduces the disposal of waste in nature. In this experiment work, the use of these wastes in the concrete has been studied. Preliminary tests like specific gravity, fineness modulus, and water absorption have been carried out on the materials. Various mix designs are prepared by partial replacement of cement with fly ash and paper pulp, and sand is completely replaced with the quarry dust, and coarse aggregate is replaced with shredded plastic waste to create sustainable concrete. A comparative study on the properties like slump cone, the weight of the cubes, compressive strength and split tensile strength, and feasibility of such concrete has been carried out. Results indicated that the weight of cubes started to decrease with the addition of waste. Compressive strength and split tensile strength show that the strength started to fall with the addition of plastic. The cost of concrete decreased with the addition of waste. 5 % of plastic waste in concrete and 3 % of paper pulp, and 5 % of fly ash is considered the optimal replacement percentage.

One of the most energy-intensive processes is the drying process. Therefore, an important task is to reduce heat consumption for drying. Various ways to improve the drying devices of paper and cardboard machines are identified. The main disadvantages of these improvements are given. The limiting factor of heat transfer from water vapor to paper is established. The dependence of thermal resistance on the thickness of the condensate layer is given. The authors have developed a new design for condensate drainage. The developed design allows installing movable siphons without replacement of steam inlet heads of the old type (for fixed siphons) with their insignificant modernization and cutting of an annular groove inside the drying cylinder. This will ensure a minimum level of condensate and eliminate the possibility of suction of steam into the condensate return system. Additionally, this will reduce thermal resistance, heat loss, and reduce energy consumption for paper drying as a whole.

New Ukrainian and world realities set new tasks for the higher educational establishments, which are related to the search for new, modern methods that allow to increase the effectiveness of training. Currently, topical are the issues of not only professional but also the personal development of the student forming the priority in the implementation of educational activities in universities, preparation for future professional activities, as well as for successful interaction in society. The concept of «individual social competence» is an important factor in creating a system of educational process which takes into account aspects of professional development, and at the same time the peculiarities of the formation of the student personality. The author analyses the concept of «competence», considers the key competences for lifelong learning, identified by the European Parliament and the Council of the European Union, including social competence, studies the scientific achievements of Ukrainian and foreign scientists, including G. Gedviliene, H. S. Han, K. M. Kemple, U.P. Kanning, M. Horenburg, G.W. Ladd, H. K. Ma, K. Monahan, M. Monnier, O.V. Varetska, N.I. Hlebova, D.V. Hubareva, O.I. Hura, M.O. Doktorovych, I.B. Zarubinska, O.O. Subina, V.M. Shakhrai. They explored different aspects of social competence of different age categories. The author concludes that, despite different interpretations, all scientists agree that social competence is an acquired skill, it can be formed and developed throughout life. It was also determined that the developed social competence determines the status of the individual in society, it affects the success in professional activities. The high level of social competence allows a person not only to be realized in professional activities, but also to influence the processes in society, which in turn determines its stability. The author’s definition of the concept of «individual social competence» is given in the paper; the author concludes that social competence is an integrated ability that contains other competencies: spiritual, civic, communicative, linguistic; the concept of social competence is closely related to professional competence, without the successful interaction of the individual with society it is impossible to acquire the skills and abilities inherent in a qualified specialist. Thus, an important task for modern higher education is the formation and development of social competence of students, which is the key to successful implementation of the future specialist in professional activities. The educational process should be aimed at forming a system of knowledge about interaction in society, understanding the system of social values, ability to cooperate in society, the ability to communicate constructively, because only a socially competent person can.

Maintaining of the proper predetermined paper pulp consistency on the different stages of the paper or cardboard manufacturing process significantly affects on quality and self cost of manufactured articles. The improvement of precision and repeatability of the paper pulp viscosity and consistency measurements is relevant to paper industry. Objective of the work is to improve the industrial-type paper pulp rotational consistometer. A new method for measurement of paper pulp concentration by means of a rotational viscometer was suggested which enables determining the flow consistency index K and flow behavior index n in the Ostwald-de Waele power law. The influence of the following torques on the measurement results is eliminated thanks to the new method: the friction torque in the seal of the sensitive element, the friction torque in the bearings of the shaft and the torque created under the influence of the flow with distorted flow speed profile. This is achieved by measuring the torque which acts on the sensitive element approaching the selected frequencies of sensitive element rotation both from the lower and higher frequencies. The mean torque value is calculated based on the obtained values. The measurements are conducted for two sensitive element rotation frequencies adjusted in advance. The frequency of sensitive element rotation is changed by means of a frequency converter. It is shown that by using two different rotation frequencies of the sensitive element of a rotational viscometer it is possible to define the flow consistency index and the flow behavior index. Paper pulp viscosity and consistency is defined on the basis of these two indexes. It is also suggested to average the results of viscous friction torque measurement approaching the rotation frequency of the viscometer sensitive element to the working frequency chosen for measurement from the lower and higher frequency ranges. By averaging the results of such measurement the friction torques in sealing and bearings supporting the sensitive element shaft are compensated. By changing the rotation direction of the sensitive element and by further averaging the obtained results it is possible to eliminate the influence of the asymmetrical distribution of paper pulp flow speed in the pipeline. This improves accuracy of the paper pulp consistency measurement.

Background. Development of technology for obtaining peracetic pulp from oat straw and its use in the production of one of the paper mass types. Objective. Determination of peracetic cooking technological parameters’ optimal values for oat straw peracetic cellulose quality indicators. Methods. The oat straw cooking was carried out with peracetic acid at 95 ± 1 °C from 90 to 180 min for hydromodulus 8:1 and 7:1, using a sodium tungstate catalyst. To determine the oat straw peracetic cellulose mechanical indexes, laboratory samples of paper weighing 70 g/m2 were made. Results. Technological parameters’ optimum values (temperature, cooking duration, hydromodulus, hydrogen peroxide and acetic acid concentration) for the oat straw delignification process were established. It is shown that the sodium tungstate catalyst addition to the cooking solution at a rate of up to 1 % of the plant raw material weight helps to reduce the lignin content in cellulose to 15 %. A diagram of the cellulose yield dependence on its residual lignin content for various methods of non-wood plant material species delignification is constructed. The high efficiency of the peracetic method for obtaining cellulose from non-wood plant raw materials, in particular from oat straw, has been confirmed. It is determined that the obtained peracetic cellulose from oat straw has high mechanical indexes. Conclusions. Oat straw peracetic cellulose can be used for the production of paper and cardboard mass types, in particular wrapping paper.

Lipoedema is a chronic progressive disorder of adipose tissue leading to an enlargement of lower extremities. It is considered to be rare; however, the prevalence of the disease is underestimated because it is commonly misdiagnosed as obesity or lymphedema and the general awareness is poor. The etiology of the disorder is considered to be multifarious, including genetic inheritance, hormonal imbalance and microcirculation alterations. Diagnosis is mainly based on medical history and physical examination. Management of lipoedema is focused on reducing the symptoms, improving the quality of life and preventing further progression of the disease. The aim of this paper is to raise the awareness of the disease and provide appropriate clinical guidance for the assessment of lipoedema. We searched through the PubMed/MEDLINE database and took into consideration all of the results available as of 6September, 2020 and outlined the current evidence regarding lipoedema epidemiology, etiology, clinical presentation, differential diagnosis, and management. Better understanding of lipoedema is crucial for establishing an early diagnosis and a proper treatment, which in turn will reduce the psychological and physical implications associated with the disease.