bluuebunny/crossref_metadata_2025 huggingface dataset:
Mosquito hypersensitivity may be associated with atopic background in children
Authors: Yavuz Süleyman Tolga , Akin Onur , Koc Ozan , Güngör Ali , Bolat Ahmet , Gülec Mustafa
Published: November 2021

Background Many children encounter unusual or “exaggerated” reactions such as large local, atypical or systemic reactions after mosquito bites.
Objective The aim of this study was to document the clinical features of children with mosquito allergy and investigate the possible associations between demographic features and type of reactions in this population.
Methods Children with large local or unusual reactions after mosquito bites who attended to our outpatient pediatric allergy department were enrolled in the study along with control subjects.
Results A total of 180 children (94 with mosquito allergy and 86 age and sex-matched control subjects) with a median age of 6.8 years (IQR 5.5–9.3) were enrolled. Atopy (35.1% vs. 11.6%, p < 0.001) and grass pollen sensitization (28.7% vs. 8.1%, p < 0.001) were significantly more frequent in children with mosquito allergy. Skin prick test with mosquito allergen was positive in only 6 children (6,4%). Grass pollen sensitization was most common in children (28.7%) followed by sensitization to house dust mite (9.6%). 30 children (31.9%) had an accompanying atopic disease such as allergic rhinitis, asthma or atopic dermatitis. Bullae were significantly more frequent in children with asthma (41.7% vs.15.9, p = 0.034). The median duration of symptoms after onset were significantly longer in patients with ecchymosis, with immediate wheals and in children whose symptoms start in 20 min to 4 hours after mosquito bites.
Conclusion There is an association between unusual, large local or exaggerated reactions after mosquito bites and allergic diseases in children. The severity of reactions increases with age and particularly in children with atopic background.
Establishing the conditions for the formation of a near-wall layer of solid granular fill of a rotating drum
Authors: Naumenko Yuriy , Deineka Kateryna , Myronenko Tamara
Published: November 2021

This paper reports the assessment of the influence of dynamic motion parameters on the formation and disappearance at the cylindrical surface of the chamber of the rotating drum of the near-wall layer of non-loose granular fill.
Based on the results of experimental visualization of the flow, the effect of solidity on the behavior of granular fill was revealed. The hydrodynamic effect of fill quasi-liquefaction under the action of solidity has been established, which involves the occurrence of a connecting interaction between adjacent layers and the surface of the chamber. Conversion of shear circulation flow to homogeneous dense clustered stream with slipping and rolling without relative movement of particles was detected.
The hydrodynamic characteristics of circulation flow transition to the near-wall layer mode during rotation acceleration have been defined. Such a transition is implemented by smoothly increasing the thickness of the layer when the rest of the fill is circulated at the bottom of the chamber.
The effect of the rheological hysteresis of the movement of the rotating chamber fill, caused by quasi-liquefaction of non-loose granular environment, has been established. The effect implies exceeding the speed limit ωfl in the formation of a near-wall layer, at rotation acceleration, above the boundary ωdl of the layer disappearance when the rotation slows down. The manifestation of hysteresis mainly increases with an increase in Reynolds number. The intensity of increased hysteresis manifestation increases with a decrease in the degree of filling the chamber. The value of the Froud number for the ωfl and ωdl boundaries increases with the increase in Re. It has been established that at the relative particle size of the dispersed fill ψdc≈(0.065–1.04)·10‑3 and Re=30–500, Fr=1–2.9, for the ωfl boundary, and Fr=0.5–1.4, for the ωdl boundary. The Fr value for the ωfl limit was found to exceed this value for the ωdl boundary by 1.6–2.1 times.
The established effects make it possible to substantiate the rational parameters for the grinding process in drum-roll mills
Analysis of fault diagnosis of DC motors by power consumption pattern recognition
Authors: Majdi Hasan Shakir , Shijer Sameera Sadey , Hanfesh Abduljabbar Owaid , Habeeb Laith Jaafer , Sabry Ahmad H.
Published: November 2021

Early detection of faults in DC motors extends their life and lowers their power usage. There are a variety of traditional and soft computing techniques for detecting faults in DC motors. Many diagnostic techniques have been developed in the past to detect such fault-related patterns. These methods for detecting the aforementioned potential failures of motors can be utilized in a variety of scientific and technological domains. Motor Power Pattern Analysis (MPPA) is a technology that analyzes the current and voltage provided to an electric motor using particular patterns and protocols to assess the operational status of the motors without disrupting production. Engineers and researchers, particularly in industries, face a difficult challenge in monitoring spinning types of equipment. In this work, we are going to explain how to use the motor power pattern/signature analysis (MPPA) of a power signal driving a servo to find mechanical defects in a gear train. A hardware setup is used to simplify the demonstration of obtaining spectral metrics from the power consumption signals. A DC motor, a set of metal or nylon drive gears, and a control circuit are employed. The speed control circuit was eliminated to allow direct monitoring of the DC motor's current profiles. Infrared (IR) photo-interrupters with a 35 mm diameter, eight-holed, standard servo wheel were employed to gather the tachometer signal at the servo's output. The mean value of the measurements was 318 V for the healthy profile, while it was 330 V for the faulty gears power data. The proposed power consumption profile analysis approach succeeds to recognize the mechanical faults in the gear-box of a DC servomotor via examining the mean level of the power consumption pattern as well as the extraction of the Power Spectral Density (PSD) through comparing faulty and healthy profiles
Devising a method for constructing the optimal model of time series forecasting based on the principles of competition
Authors: Mulesa Oksana , Povkhan Igor , Radivilova Tamara , Baranovskyi Oleksii
Published: November 2021

This paper reports the analysis of a forecasting problem based on time series. It is noted that the forecasting stage itself is preceded by the stages of selection of forecasting methods, determining the criterion for the forecast quality, and setting the optimal prehistory step. As one of the criteria for a forecast quality, its volatility has been considered. Improving the volatility of the forecast could ensure a decrease in the absolute value of the deviation of forecast values from actual data. Such a criterion should be used in forecasting in medicine and other socially important sectors.
To implement the principle of competition between forecasting methods, it is proposed to categorize them based on the values of deviations in the forecast results from the exact values of the elements of the time series. The concept of dominance among forecasting methods has been introduced; rules for the selection of dominant and accurate enough predictive models have been defined. Applying the devised rules could make it possible, at the preceding stages of the analysis of the time series, to reject in advance the models that would surely fail from the list of predictive models available to use.
In accordance with the devised method, after applying those rules, a system of functions is built. The functions differ in the sets of predictive models whose forecasting results are taken into consideration. Variables in the functions are the weight coefficients with which predictive models are included. Optimal values for the variables, as well as the optimal model, are selected as a result of minimizing the functions built.
The devised method was experimentally verified. It has been shown that the constructed method made it possible to reduce the forecast error from 0.477 and 0.427 for basic models to 0.395 and to improve the volatility of the forecast from 1969.489 and 1974.002 to 1607.065
The study and scientifical substantiation of critical control points in the life cycle of immunostimulating products such as pastila and marmalade
Authors: Belozertseva Olga , Baibolova Lyazzat , Pronina Yuliya , Cepeda Alberto , Tlevlessova Dinara
Published: November 2021

Based on the study results, this paper reports a technology to produce natural fruit and berry pastila and marmalade of improved nutritional and biological value with a long shelf life. Critical control points of product safety have been identified and scientifically substantiated. The technological process to prepare pastila and marmalade involves exposing the raw materials to high and low temperatures while maintaining certain indicators of the content of dry substances. The identification feature of marmalade products is the content of a certain type of fruit raw materials, which poses risks throughout the life cycle of product manufacturing despite the fact that the preparation and storage of the raw materials implies the temperature range from 0 °C to minus 15 °C. Problematic issues of mold occurrence have been considered. It was established that the moisture content in the product above 15 % leads to an increase in the content of mold fungi and significantly reduces its shelf life. This paper gives the results of a study to identify the preservation of vitamin C in products prepared from fresh berries and from berries subjected to freezing. It was revealed that in the process of storing the raw materials at a temperature of minus 15 °C, the amount of vitamin C in the resulting product decreased by 11.3 % compared to the product prepared from fresh raw materials. The maximum limit of the high preparation temperatures of 108 °C did not significantly affect the loss of vitamin C. Studies were conducted to determine the sugar content in products whereby a high fructose content was identified. Critical control points at all stages of production were determined, which has made it possible to choose the optimal technological modes and parameters for the safety and quality of the product
Devising a procedure for justifying the need for samples of weapons and weapon target assignment when using a reconnaissance firing system
Authors: Maistrenko Oleksandr , Khoma Vitalii , Lykholot Oleksandr , Shcherba Andrii , Yakubovskyi Oleksandr , Stetsiv Stanislav , Kornienko Alexander , Savelіev Andrii
Published: November 2021

This paper proposes an algorithm to substantiate the need for weapons samples, as well as targeting when using a reconnaissance firing system taking into consideration the peculiarities of functioning of such systems. The algorithm essentially implies streamlining the stages in determining the magnitude of the reduction of the enemy's combat potential and, on its basis, the formation of the need for the number of weapons by type. The algorithm makes it possible to take into consideration the nonlinearity of functions that describe both different types of weapons and targets. In addition, this algorithm is based on a modified method of nonlinear programming (two functions). The modification involves the use of a normalized share of the weight of each target as weight coefficients. This allows for targeting while taking into consideration the established level of the combat potential of an enemy.
A procedure for determining the need for samples of weapons and targeting in the use of reconnaissance firing systems has been devised. It was determined that in order to achieve the goal of enemy fire damage, it is not typically necessary to use all weapons samples. In general, the procedure makes it possible to take into consideration the peculiarities of the samples of weapons and their suitability to hit a certain target. That could prevent problems with overspending of resources, failures in the detection-defeat cycle, non-fulfillment (not fully performing) tasks during enemy fire damage.
In general, the algorithm and procedure for determining the need for the samples of weapons and targeting when using a reconnaissance firing system testify to devising a methodology for justifying the need for weapons samples and targeting. The performance and adequacy of this procedure have been tested by considering an example of determining the need for weapons samples and targeting and obtaining the result confirmed by the experience in the use of reconnaissance firing systems
Development of a method for assessing the security of cyber-physical systems based on the Lotka–Volterra model
Authors: Yevseiev Serhii , Pohasii Serhii , Milevskyi Stanislav , Milov Oleksandr , Melenti Yevgen , Grod Ivan , Berestov Denis , Fedorenko Ruslan , Kurchenko Oleg
Published: November 2021

The paper presents the results of the development of a method for assessing the security of cyber-physical systems based on the Lotka–Volterra model. Security models of cyber-physical systems are proposed: “predator–prey” taking into account the computing capabilities and focus of targeted cyberattacks, “predator–prey” taking into account the possible competition of attackers in relation to the “prey”, “predator–prey” taking into account the relationships between “prey species” and “predator species”, “predator–prey” taking into account the relationship between “prey species” and “predator species”. Based on the proposed approach, the coefficients of the Lotka–Volterra model α=0.39, β=0.32, γ=0.29, φ=0.27 were obtained, which take into account the synergy and hybridity of modern threats, funding for the formation and improvement of the protection system, and also allow determining the financial and computing capabilities of the attacker based on the identified threats.
The proposed method for assessing the security of cyber-physical systems is based on the developed threat classifier, allows assessing the current security level and provides recommendations regarding the allocation of limited protection resources based on an expert assessment of known threats. This approach allows offline dynamic simulation, which makes it possible to timely determine attackers' capabilities and form preventive protection measures based on threat analysis. In the simulation, actual bases for assessing real threats and incidents in cyber-physical systems can be used, which allows an expert assessment of their impact on both individual security services and security components (cyber security, information security and security of information).
The presented simulation results do not contradict the graphical results of the classical Lotka–Volterra model, which indicates the adequacy of the proposed approach for assessing the security of cyber-physical systems
Determining the dynamics of carbon monoxide formation during gas welding processes
Authors: Berezutskyi Viacheslav , Khondak Inna , Berezutska Nataliia
Published: November 2021

This paper reports a study of the air medium where welding processes take place, with special attention paid to the evolution of carbon monoxide (CO) in the working medium in the process of gas welding. Plots were constructed and polynomial dependences were obtained to show a change in the concentration of carbon monoxide in the air of the working area during gas welding.
It was confirmed experimentally that the concentration of carbon monoxide exceeds the permissible sanitary and hygienic indicators MPC (20 mg/m3) during gas welding. As a result of the experiment, the effectiveness of the use of an additional device was proven, namely an umbrella gas concentrator, in order to capture welding gases that are formed during gas welding. It was established that the MPC is exceeded under certain working conditions and welding wire. The carbon monoxide formation during gas welding was analyzed; these processes were compared with electric arc welding. The mathematical dependences derived make it possible to assess the risks of the welders’ work and conclude that the electric arc welding is characterized by a much higher rate of CO evolution from the beginning of the welding process (8.5 mg/s), that speed then decreases over 20 s by 2 times (to 4.5 mg/s). In 90 s, the speed becomes constant, to 2 mg/s. In comparison, gas welding has almost the same rate of CO formation, namely 0.3–0.9 mg/s.
By changing the types of welding wires used in gas welding and taking into consideration the type of material that needs to be welded (including the period of its use), it is possible to influence the volume of CO emissions entering the working area and an employee’s respiratory area
Improving marshmallow production technology by adding the fruit and vegetable paste obtained by low-temperature concentration
Authors: Bondar Mariana , Solomon Alla , Fedak Natalia , Paska Mariia , Hotvianska Anna , Polozhyshnikova Lyudmila , Mironov Denys , Kushch Larisa
Published: November 2021

A formulation composition and a low-temperature technique have been devised for concentrating fruit and vegetable puree with the following component content: 20 % apple; 20 % pumpkin; 15 % beets; 15 % cranberries; 15 % hawthorn. The puree is concentrated in a rotary evaporator to a solids content of 50 % at a temperature of 50...56 °C under vacuum. The processing time was reduced to 1...2 min, which is several times less compared to conventional single-case pump vacuum evaporators (60...90 mins). Reducing the temperature influence of concentrating contributes to an increase in the organoleptic and physicochemical parameters of the resulting paste. To determine the effect of the contribution of each component to the structure of the paste, the structural and mechanical properties of the puree from each raw material and concentrated semi-finished products were investigated. The devised paste has an increased strength of the structure with a dynamic viscosity value of 394 Pa⋅s, which is 2.5 times more than that in the control sample. The devised blended fruit and vegetable paste has an increased content of physiologically functional ingredients and good organoleptic parameters, unlike control (apple paste).
It was established that the partial replacement of apple puree in the formulation composition of marshmallow with 75 % of the devised multicomponent fruit and vegetable paste gives the product original properties. The dynamic viscosity value of the marshmallow in which 75 % of apple puree was replaced with the devised paste has increased, compared to the control sample (marshmallow without additives), from 408 Pa⋅s to 908 Pa⋅s. The color of the marshmallow mass where 75 % of apple puree were replaced is bright pink with a wavelength of 596.7 nm and a brightness of 62.3 %. The data reported here make it possible to improve the quality of original marshmallow products when adding fruit and vegetable semi-finished products whereby an increase in functional properties is provided
Determining the effect of pH-shifting treatment on the solubility of pumpkin seed protein isolate
Authors: Gao Dan , Helikh Anna , Duan Zhenhua
Published: November 2021

Pumpkin seed protein is a high-quality plant protein, which has all essential amino acids for the human body and can also supply essential amino acid histidine for children. When it is introduced to food products, it needs to meet some functional properties, such as solubility, emulsifying ability, foaming ability, and so on. Among them, solubility is very important because it has a great influence on other functional properties of protein. In this study, pH-shifting treatment, which is a novel method to modify protein, is applied to improve the solubility of pumpkin seed protein isolate (PSPI). PSPI treated by pH-shifting treatment was investigated at different pH values (pH 2, pH 4, pH 6, pH 8, pH 10, and pH 12), which were labeled as PSPI 2, PSPI 4, PSPI 6, PSPI 8, PSPI 10, and PSPI 12, respectively. Compared to that of control PSPI (45.6 %), only the solubility of PSPI 8 (55.5 %) showed increased (p<0.05) value, while the solubility of PSPI 2 (13.7 %), PSPI 4 (10.8 %), PSPI 10 (41.8 %), and PSPI 12 (13.4 %) showed decreased (p<0.05) value. Then the average particle size, zeta potential of the soluble protein in PSPI were analyzed, and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was performed. PSPI 2, PSPI 4, and PSPI 12 showed decreased (p<0.05) average particle size after the pH-shifting process. And PSPI 2, and PSPI 12 showed decreased (p<0.05) zeta potential. While other samples didn’t show any significant difference in these two indicators. Besides, the molecular weight of the increased abundance of soluble protein bands was observed at 33 kDa and 25 kDa of PSPI 8. As the solubility of PSPI 8 increased (p<0.05) significantly, it might suggest the PSPI after pH-shifting treatment under pH 8 has more advantages to be used in the food industry
A study of the possibilities of using linseed flour and rice husk fiber as an additional source of raw materials in the bakery industry
Authors: Moldakulova Zilikha , Bayisbayeva Meruyet , Iskakova Galiya , Dikhanbayeva Fatima , Izembayeva Assel , Sottnikova Viera
Published: November 2021

The paper is devoted to solving the problem of the nutritional and biological value of rye-wheat bread by enriching it with non-traditional local plants raw materials – linseed flour and rice husk fiber. Rice husks are rarely used in bakery production, and in most cases remain unprocessed. However, this research defined the right ways for using them and set as a preliminary work in this field. The study has been carried out in two stages: firstly, linseed flour was added to the rye-wheat bread recipe in an amount of 5; 10; 15; 20 % to the weight of wheat flour. Secondly, dietary fiber was added to these experimental samples, prepared from rice husks without removing amorphous silicon dioxide in an amount of 0.3; 0.5; 0.7 % to the total mass of rye-wheat flour. The optimization of the ratios of the flour components with a simplex-lattice design was carried out and the rheological measurements of dough and bread were conducted on the farinograph and Chopin alveograph.
The study results experimentally found that mixtures of rye-wheat flour and linseed flour with the addition of fiber as “medium in strength” give bread with sufficient volume. The recipe optimization parameters indicated that rational percentage of fiber and linseed flour up to 0.5 % and 15 %, respectively allows increasing the nutritional and biological value of finished products, improves the crumb structure, gas-holding and water-holding capacity of bread, which in turn prevents the stale process and thereby increases the shelf life of finished products.
The obtained results allow us to suggest that, this recipe optimization model could be used in further research, as studies in this direction are limited
Research on structure and technological parameters of multi-channel cold spraying nozzle
Authors: Hu Wenjie , Tan Kun , Markovych Sergii , Cao Tingting
Published: November 2021

Cold spraying technology is a method to obtain coating by the high-speed collision of particles with the substrate through supersonic (300–1200 m/s) propulsion gas. The deposition process is mainly mechanical bonding, which has attracted more and more attention in engineering applications. The critical component of a cold spraying system is the nozzle. The performance of the nozzle directly affects the quality of the material surface coating. Therefore, the discussion of the nozzle is of great significance. At present, there are many examples of cold spraying single-channel nozzles in engineering, but there are few reports about multi-channel cold spraying nozzles. This paper explores and studies the multi-channel cold spraying nozzle, designs a special three internal channel nozzle, and adopts a 90° angle in the divergent section of the nozzle. When spraying in a small area, the nozzle with angle has apparent advantages for spraying more areas. The powder injection pressure, particle size, recovery coefficient, and internal channel position are analyzed, which affect the particle trajectory. Combined with these factors, the multi-channel nozzle is optimized and improved to solve the problem of particle collision with the inner wall of the nozzle. Finally, the technological parameters of aluminum, titanium, copper, nickel, magnesium, and zinc powders are preliminarily studied using the multi-channel nozzle. The results show that the multi-channel nozzle meets the critical velocity requirements of copper, magnesium, and zinc powder spraying in the homogeneous (powder and matrix are the same material) and aluminum powder spraying in the case of heterogeneous (powder and matrix are different materials), the multi-channel nozzle has a sound engineering application prospect and provides a specific reference for relevant technicians.
Devising an integrated method for evaluating the efficiency of scrum-based projects in the field of information technology
Authors: Prokopenko Tatiana , Lavdanska Olha , Povolotskyi Yaroslav , Obodovskyi Bohdan , Tarasenko Yaroslav
Published: November 2021

An integrated method for evaluating the effectiveness of projects in the field of information technology has been proposed, which could ensure effective management decision-making. All features inherent in the implementation of the Scrum methodology used in the management of information technology projects have been taken into consideration. Ambiguous situations that constantly arise during the implementation of projects affect their effectiveness. Therefore, constant monitoring of the project efficiency would provide opportunities for the project manager to make management decisions promptly, which could contribute to improving the efficiency of the project. The integrated method for evaluating the effectiveness of projects was devised in the class of organizational-technological systems based on the combined use of formalized, intelligent, and expert methods. The results of applying a given method include an increase in the project efficiency by 1.52 % by complying with time limits, a reduction in the overspending of financial resources and losses during the project, as well as the improved productivity of teamwork.
A model of the project efficiency index has been devised, which would ensure taking into consideration the peculiarities of the organizational and technological components of the project, as well as establishing a logical connection between the criteria that characterize the organizational component of the project, on the one hand, and the project-technological component, on the other. The resulting project efficiency index contributes to further research of various alternative scenarios for the project implementation and forecasts the dynamics of achieving strategic goals, as well as the dynamics of process implementation.
The proposed procedure for evaluating the effectiveness of the project under Scrum conditions could become the basis of the information technology of project management and the appropriate decision support system
Constructing and analyzing mathematical model of plasma characteristics in the active region of integrated p-i-n-structures by the methods of perturbation theory and conformal mappings
Authors: Bomba Andrii , Moroz Igor , Boichura Mykhailo
Published: November 2021

The results of mathematical modeling of stationary physical processes in the electron-hole plasma of the active region (i-region) of integral p-i-n-structures are presented. The mathematical model is written in the framework of the hydrodynamic thermal approximation, taking into account the phenomenological data on the effect on the dynamic characteristics of charge carriers of heating of the electron-hole plasma as a result of the release of Joule heat in the volume of the i-th region and the release of recombination energy. The model is based on a nonlinear boundary value problem on a given spatial domain with curvilinear sections of the boundary for the system of equations for the continuity of the current of charge carriers, Poisson, and thermal conductivity. The statement of the problem contains a naturally formed small parameter, which made it possible to use asymptotic methods for its analytical-numerical solution. A model nonlinear boundary value problem with a small parameter is reduced to a sequence of linear boundary value problems by the methods of perturbation theory, and the physical domain of the problem with curvilinear sections of the boundary is reduced to the canonical form by the method of conformal mappings. Stationary distributions of charge carrier concentrations and the corresponding temperature field in the active region of p-i-n-structures are obtained in the form of asymptotic series in powers of a small parameter. The process of refining solutions is iterative, with the alternate fixation of unknown tasks at different stages of the iterative process. The asymptotic series describing the behavior of the plasma concentration and potential in the region under study, in contrast to the classical ones, contain boundary layer corrections. It was found that boundary functions play a key role in describing the electrostatic plasma field. The proposed approach to solving the corresponding nonlinear problem can significantly save computing resources
Comprehensive approach to the efficiency assessment of the business model of the aviation enterprise based on business process innovation
Authors: Poberezhna Zarina
Published: November 2021

The improvement of theoretical and methodological approaches to the formation of innovativeness of business processes of enterprises has been carried out. A model of innovativeness of business processes has been formed, which takes into account the principles, goals, methods of improving the management of business processes and the factors of influence on them.
The main directions of the formation of an effective business model of an aviation enterprise based on the innovativeness of business processes are investigated and strategic directions of its provision are proposed. At the same time, the following aspects of enhancing the innovative activity of an aviation enterprise are highlighted as: the influence of the external and internal environment, innovative activity, analysis of the innovative potential and innovativeness of business processes.
An integrated approach to assessing the effectiveness of the business model of an aviation enterprise based on the innovativeness of business processes has been formed. This approach allows to provide the necessary level of innovative flexibility of the aviation enterprise and independence in the application of innovative business processes. The author has carried out a practical implementation of the applied approach at aviation enterprises. The study made it possible to identify the most important business processes for aviation enterprises. These include: the level of support (provision) of innovation, the turnover ratio of current assets, the provision of material and technical resources. As a result of the assessment, these business processes have the highest scores (4.55; 4.43 and 4.26, respectively). The assessment of the financial stability of aviation enterprises in the market was carried out and the indicators of the assessment were calculated. An integral indicator of the financial stability of aviation enterprises has been determined, according to which the problems of the effective functioning of Ukrainian aviation enterprises have been identified. At the same time, small aviation enterprises suffer losses and are characterized by a low level of financial stability
Development and verification of mechanical characteristics of a composite material made of a thermoplastic matrix and short glass fibers
Authors: Isametova Madina , Abilezova Gazel , Dishovsky Nikolay , Velev Petar
Published: November 2021

The paper presents the results of computer modeling and prediction of the mechanical properties of composite materials with a polycarbonate matrix filled with short glass inclusions. At the micro-level, the influence of the volume of inclusions on the mechanical properties of the designed composite based on polycarbonate matrix is studied in the DIGIMAT (France) program. It was found that with a ratio of the sizes of inclusions in the range of 468÷60, the particles have a needle shape, and the material with such inclusions has a higher stress limit and elastic modulus than with a shape coefficient less than 50. The components of the fiber orientation tensor were also determined, at which the values of computer modeling are in good agreement with experimental data. The influence of the size of the finite element grid on the characteristics of the composite at the macro level was studied, and recommendations were given for choosing the size of the face of the finite element. The adequacy of computer models was confirmed by the results of field tests. The paper presents the results of testing flat samples made by injection molding technology. Mechanical tests were carried out for three variants of samples made of composite material based on a polycarbonate matrix with 10 %, 20 % and 30 % inclusions. The discrepancy between the experimental and computer results for samples with 10 %, 20 % content of short chopped fibers is explained by the influence of technological factors on the properties of the material at the macro-level.
The conducted research allowed us to develop a computer modeling technique used at the stage of development of polymer composites based on thermoplastic matrices with short glass inclusions
Application of partial areas method in the problem of sound radiation by a sphere in a waveguide with soft acoustically boundaries
Authors: Korzhyk Oleksii , Naida Sergey , Zheliaskova Tetiana , Chaika Oleksander , Naida Nikita
Published: November 2021

The paper considers the features of the formation of an acoustic field by a spherical source with complicated properties in a regular plane-parallel waveguide, which is of practical importance in marine instrumentation and oceanographic research. The calculation algorithm is based on the use of the Helmholtz equation and the Fourier method for each partial region and the conjugation conditions on their boundaries. The presented calculation allows one to get rid of the idealized boundary conditions on the source surface, with the subsequent determination of the excitation coefficients of the waveguide modes within the framework of the Sturm-Liouville problem. In this case, the attraction of the boundary conditions on the surface and the bottom of the sea, as well as the Sommerfeld conditions, makes it possible to obtain the real distribution of the field in the vertical sections of the waveguide.
The obtained frequency dependences of the pressure and vibrational velocity components show their amplitude-phase differences, which reach 90 degrees, which partially explains the appearance of singular points in the intensity field in a regular waveguide. It has been determined that multiple reflections of sound waves from the boundaries of the working space and the space of the waveguide cause oscillations of the pressure components with a change in the amplitude level up to 6 dB. It was found that with an increase in the size of the source, a kind of resonance is formed in the working space, the frequency of which depends on the depth of the sea and corresponds to the region kr=x=5.8. It was found that when the acoustic field is formed in the working space, the frequency response of the impedance components is represented as a multiresonant dependence formed on the basis of the frequency characteristics of the lower modes and their combinations. Experimental studies have shown that the results of calculations of the mode composition of the acoustic field of the emitter, obtained in the conditions of the pool, correspond to the spatial characteristics of the mode components of the acoustic field with an error of up to 3 dB
Identification of white jewelry alloy based on silver and platinum for testing purposes
Authors: Artyukh Tatyana , Hryhorenko Inna , Ternova Alla , Yaheliuk Svitlana , Verenikin Oleksii , Cernavca Mihai
Published: November 2021

The procedure for the identification of white jewelry alloys based on precious metals, in particular, silver, platinum and platinum group metals with different contents of alloying components, by testing on an assay stone and by the method of X-ray fluorescence analysis has been considered. The methodology for assessing the compliance of silver and platinum fineness in white jewelry alloys of different component composition with the requirements of regulatory documents and the procedure for their identification has been improved.
It has been established that the silver fineness in precious alloys of the AgCu, AgZnCu system, determined using the potassium dichromate reagent on the test stone, depends on the manifestation of the contrast of the qualitative reaction from the standard sample (assay needle).
It has been proven that for testing silver alloys containing palladium, the "Acid reagent for gold 750" is effective, which works to determine the qualitative and approximate content of silver in alloys.
It was determined that the reagent "Ferrous-cyanide potassium" is very sensitive to changes in the alloy composition of silver alloys and makes it possible to establish the silver content with an accuracy of 5 %. The presence in silver alloys of such impurities as zinc, cadmium, nickel, gold, palladium and others increases the error in determining the fineness of silver and forms a different color and shade.
It has been proven that testing of silver alloys on an assay stone with silver nitrate is effective only for the СрМ system. The presence of zinc in 925 sterling silver alloys visually increases the color intensity of the sediment, which indicates a higher overestimated fineness.
It has been found that the identification of the content of precious alloys based on platinum for the presence of ligature components is carried out with a potassium iodide reagent at t=120 °C by the color and shade of the sediment.
The procedure for using potassium iodide during testing of precious platinum-based alloys has been optimized
Development mechanical and fatigue properties of AA7001 after combined SP with deep cryogenic treatment and UIP with deep cryogenic treatment
Authors: Alhamdany Aseel A. , Khenyab Ali Yousuf , Mohammed Qusay K. , Alalkawi Hussain Jasim M.
Published: November 2021

Al alloys have long been of interest to the aerospace community, due to their modest specific strength, ease of manufacture, and low cost. In recent years, with the rapid development of weaponry, 7XXX ultra-high strength aluminum alloys used increasingly in military ﬁelds. Chemical analysis of the AA 7001 is supported out at The Company State for Engineering, Rehabilitation and Inspection (SIER) in Iraq. Strengthening the surface (shot penning) is beneficial to delay crack nucleation and extend life. The test samples (tensile and fatigue) are subject to the SP process by using ball steel with the parameters (Pressure=12 bars, Speed=40 mm/min, Distance=150 mm, Shot size=2.25 mm, Coverage=100 %). The ultrasonic impact treatment (UIP) machine is used for enhancing the surface properties. For the Deep Cryogenic Treatment (DCT), the samples have been placed in the cooling chamber. A standard tensile test specimen is prepared in a round section with the dimensions chosen according to ASTM (A370-11). Tensile and fatigue of rotating bending with R=–1 have been conducting, after the effect of deep cryogenic treatment (DCT), combined shot peening (SP+DCT), and ultrasonic impact peening (UIP+DCT) of AA7001 have been examining. The maximum improvement percent in ultimate tensile strength (UTS) due to (DCT), (SP+DCT), and (UIP+DCT) were about 3 %, 8.27 %, and 6.25 %, respectively. The rise in the yield stress due to (DCT), (SP+DCT), and (UIP+DCT) were 9.5 %, 14.6 %, and 13.14 %, respectively. The ductility reduced by constituents of 8.57 %, 12.5 %, and 11.42 % sequentially. The improvement in fatigue strength in a high cycle regime is 16 % for (SP+DCT) due to combined effects, it is an 8 % increase in the endurance limit on fatigue behavior due to inducing compressive residual stress (CRS)
Research of approaches to formation of legislation in the sphere of online retail selling (distance selling) of medicines
Authors: Volkova Alina , Boldar Galyna , Ryshchenko Oksana , Proskurova Iana
Published: November 2021

The aim of the study is to study approaches to the formation of legislation in the field of the online retail selling (distance selling) of medicines in the EU with further development of areas for improvement of phar-maceutical legislation of Ukraine.
Materials and methods. During the research, scientific methods were used, in particular, system-analytical, content analysis, comparative legal, graphic, etc.
Results. The main provisions of the EU Directives 2000/31/EU “On some legal aspects of information services, in particular, electronic commerce, in the internal market” (Directive on electronic commerce) and EU Directive 2001/83 EU “On the Community code relating to medicinal products for human use”, the Council of Europe Convention “On counterfeiting medical products and similar involving threats to public health”, Implementing Regulation of the EU Commission No. 699/2014 of June 24, 2014, as well as the Law of Ukraine “On Electronic Commerce”, “On medicines”, Resolution of the Cabinet of Ministers of Ukraine (CMU) of March 23, 2020 No. 220, of November 30, 2016 No. 929 and others.
Conclusions. The main directions of improving the current legislation of Ukraine in the field of the online retail selling of medicines are proposed. The necessity to supplement the Regulation “On the State Service of Ukraine for Medicines and Drug Control” (Resolution of the Cabinet of Ministers of Ukraine of November 30, 2016 No. 929) with certain norms has been substantiated. In particular, to impose on this state body the obligation to register business entities that plan to sell drugs using information and communication means, as well as maintain their Register
Problems of false medicines' distribution and prospects of combat: survey of specialists and consumers results
Authors: Lebed Serhii , Nemchenko Alla
Published: November 2021

The aim: comparative analysis of the results of a questionnaire survey of pharmaceutical and medical professionals and consumers, conducted by the authors during 2019-2021 to identify opinions on which there are coincidences and differences, as well as an assessment of the problem of drug counterfeiting in Ukraine to develop approaches to prevent their spread.

Materials and methods. The study used scientific publications, as well as the results of a survey of specialists of the State Service of Ukraine for Medicines and Drug Control (State Medical Service) and its territorial bodies, pharmaceutical and medical professionals of health care institutions and consumers on the fight against drug falsification. The research was conducted using the methods of questionnaires, systematization and generalization.

Results. According to the results of a comprehensive questionnaire during 2019-2021, it was found that the share of CM in the Ukrainian pharmaceutical market is estimated at 5 % by a majority of respondents on average 58.5 %, including 59.7 % of experts of the State Medical Service, 42.3 % of pharmacy specialists, 11.4 % by doctors and 73.5 % by consumers. Respondents' answers about the signs of drug falsification differ significantly, so most experts believe that this is a change in the usual signs (taste, smell, color), while pharmacy specialists - labelling in a foreign language, doctors - no therapeutic effect, for consumers it is a change in packaging design (labels) and a significantly lower price. The main sales channels of CM for experts and pharmacy specialists are e-commerce (68.7 % and 75.7 %, respectively), while the majority of consumers could not determine.

Many experts and pharmacy specialists pointed to the need to introduce special security features of packaging in the form of 2d barcodes as the main method for protection and detection of CM (79.1 % and 39.6 %, respectively). Most of the surveyed pharmacy workers and consumers believe that the risk of purchasing counterfeit drugs is higher in the pharmacies of individual entrepreneurs or small pharmacy chains.The main problem that hinders the effective fight against drug counterfeiting was the imperfect legislation (68.7 %). Regarding effective tools in the fight against counterfeit drugs, experts called a significant strengthening of the powers of the regulatory body - following the example of the FDA (70.1 %).

Conclusions. It is established that the most important priorities of the state policy for combating CM in Ukraine are the improvement of the system of state control and quality assurance of medicines, in particular 2d coding, as well as the need to strengthen the responsibility for drug falsification. The results of research on the problem of drug falsification indicate the feasibility of introducing a systematic survey for a wider range of respondents - professionals and consumers
Analysis of methods for increasing the efficiency of dynamic routing protocols in telecommunication networks with the possibility of self-organization
Authors: Nalapko Oleksii , Sova Oleg , Shyshatskyi Andrii , Protas Nadiia , Kravchenko Serhii , Solomakha Andriy , Neroznak Yevhenii , Gaman Oleksandr , Merkotan Dmytro , Miahkykh Hennadii
Published: November 2021

The object of research is the military radio communication system. Effective operation of routing protocols is possible only if there is reliable information about the network topology for network nodes, given that the mobility of individual nodes is insignificant in special purpose wireless networks. Because nodes in the network demonstrate the mobility property of the node groups. This paper solves the problem of the analysis (decomposition) of methods of protocols efficiency increase of dynamic routing in telecommunication networks with a possibility to self-organization.
In the course of the research, the authors used the main provisions of the queuing theory, the theory of automation, the theory of complex technical systems and general scientific methods of cognition, namely analysis and synthesis. This research analyzes various methods to increase the efficiency of dynamic routing protocols. Energy efficiency methods focus on three main components in energy management: battery management, transmission energy management and system energy management methods. Reliable multicast has become indispensable for the successful deployment of special purpose wireless networks, such as in tactical military operations and emergency operations. The results of the research will be useful in:
– development of new routing algorithms;
– substantiation of recommendations for improving the efficiency of the route selection process in networks with the possibility of self-organization;
– analysis of the electronic situation during hostilities (operations);
– while creating promising technologies to increase the efficiency of mobile radio networks.
Areas of further research will focus on the development of a methodology for the operational management of interference protection of intelligent military radio communication systems.