bluuebunny/crossref_metadata_2025_split huggingface dataset:
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
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)
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.
Development of a simulation model for a special purpose mobile radio network capable of self-organization
Authors: Sova Oleg , Shyshatskyi Andrii , Nalapko Oleksii , Trotsko Oleksandr , Protas Nadiia , Marchenko Halyna , Kuvenov Artem , Chumak Viktor , Onbinskyi Yaroslav , Poliak Illia 
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 each of the network nodes. Construction of special purpose radio networks with the possibility of self-organization is possible only in the presence of adequate and reliable models of their work in different applications and the impact nature. It necessitates the development of new and adequate algorithms (methods, techniques) for modeling routing algorithms in special purpose radio networks with the possibility of self-organization. This work solves the problem of developing a simulation model of a mobile radio network for special purposes with the possibility of 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 simulation model was developed to assess the effectiveness and adequacy of the developed scientific and methodological apparatus for routing management in special purpose radio networks with the possibility of self-organization.
The research results 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;
‒ assessment of adequacy, reliability, sensitivity of routing algorithms;
‒ development of new and improvement of existing simulation routing models.
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.
Modernization of electrical complex for producing thermal energy for an industrial enterprise
Authors: Chebotarova Yevheniia , Perekrest Andrii 
Published: November 2021

The object of research is the electrical complex for the preparation of thermal energy at the enterprise. The electrotechnical complex is a heat supply unit that provides thermal energy to the building of the enterprise for the needs of heating, ventilation and hot water supply. One of the identified shortcomings of this facility is the overconsumption of energy resources for heating, caused by the lack of the ability to control consumption. Modernization of heat points and equipping them with automation means will provide quantitative and qualitative control of the heat carrier depending on the outside air temperature.
In the course of the study, the method of statistical data analysis was used to analyze the heat load of buildings for heating, ventilation and hot water supply, and the distribution of heat loads by the temperature of the indoor air. Also, an improved discounted method for evaluating the effectiveness of investment projects was used when calculating economic indicators and a method for calculating heat consumption for heating according to aggregated indicators when determining energy consumption for heating.
On the basis of the analysis of the heat load and a certain structure of its distribution according to the temperature of the internal air, it was found that more energy resources are consumed for heating. The largest consumer is defined as a building with an internal temperature Tin=16 °C. Calculations of the commercial attractiveness of the proposed technical solutions for buildings with an internal temperature Tin=18 °C have confirmed the feasibility of their implementation in terms of their payback, which does not exceed the period of 3.5 heated seasons.
Thanks to the modernization of heat points and the introduction of automated monitoring and regulation systems, optimal heat energy consumption will be ensured depending on the ambient temperature. Unlike other similar studies, the feasibility of introducing automated systems is determined by an improved discounted method, which allows not only to take into account the change in the value of money in the future, but also the required minimum percentage of thermal energy savings to break even projects.