bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of vibration treatment on increasing the durability of tillage equipment working bodies
Authors: Dudnikov Anatolii , Ivankova Olena , Gorbenko Oleksandr , Kelemesh Anton 
Published: May 2021

This paper reports a study into the durability of tillage equipment working bodies. It has been established that the quality of surface layers during plastic deformation depends on a series of factors. These factors include the degree of hardening, the thickness of the hardened layer, the size and nature of the distribution of residual stresses.
The study has shown that the technology to restore working bodies that involves vibration oscillations provides for higher durability.
Investigation of deformed samples demonstrates that when exposed to vibration treatment, the microstructure is more fine-grained and even; the hardness of the treated surface of a ploughshare blade increases by 22‒35 %. This contributes to hardening the machined surface.
It has been established that the tillage equipment working body wear is a random process, which is predetermined by changes in the structural dimensions and shape of cutting elements. An analysis of the wear distribution density of cutting elements has revealed its compliance with the law of normal distribution.
It should be noted that the most influential geometric parameter of a working body affecting the part’s resource is the wear depth. This parameter determines the residual thickness of the ploughshare wall.
Data from surface-layer studies at hardening make it possible to note a decrease in the limiting state of the examined parameters. In particular, the wear of a ploughshare tip was 17 % less than the limiting state.
The study of durability has shown that the amount of tillage equipment working body wear is 1.28 times less when using vibrational plastic deformation. Accordingly, when restoring ploughshares, in order to increase the working bodies’ resource, it is more expedient to use a method that implies the welding of tires made from steel 45 involving sormite surfacing and vibration treatment
Development of an image segmentation model based on a convolutional neural network
Authors: Knysh Bogdan , Kulyk Yaroslav 
Published: May 2021

This paper has considered a model of image segmentation using convolutional neural networks and studied the process efficiency based on models involving training the deep layers of convolutional neural networks. There are objective difficulties associated with determining the optimal characteristics of neural networks, so there is an issue related to retraining the neural network. Eliminating retraining by determining the optimal number of epochs only would not suffice since it does not provide high accuracy.
The requirements for the set of images for training and model verification were defined. These requirements are best met by the image sets PASCAL VOC (United Kingdom) and NVIDIA-Aerial Drone (USA).
It has been established that AlexNet (Canada) is a trained model and could perform image segmentation while object recognition reliability is insufficient. Therefore, there is a need to improve the efficiency of image segmentation. It is advisable to use the AlexNet architecture to build a specialized model, which, by changing the parameters and retraining some layers, would allow for a better process of image segmentation.
Five models have been trained using the following parameters: learning speed, the number of epochs, optimization algorithm, the type of learning speed change, a gamma coefficient, a pre-trained model.
A convolutional neural network has been developed to improve the accuracy and efficiency of image segmentation. Optimal neural network training parameters have been determined: learning speed is 0.0001, the number of epochs is 50, a gamma coefficient is 0.1, etc. An increase in accuracy by 3 % was achieved, which makes it possible to assert the correctness of the choice of the architecture for the developed network and the selection of parameters. That allows this network to be used for practical tasks related to image segmentation, in particular for devices with limited computing resources
Optimization of the main parameters of the support-lump-breaking coil
Authors: Nurimbetov Timur , Umarov Sukhrob , Khafizova Zulfiya , Bayjanov Sarsengaliy , Nazarbaev Orinbay , Mirkurbanova Rahima , Durmanov Akmal 
Published: May 2021

Agricultural land plays an important role in ensuring food security and employment in rural areas. For many years, the planned economy has forced Uzbekistan to grow water-intensive crops, which has led to declining land productivity and increased crop yields. In a market economy, new innovative technologies are in high demand not only in agriculture but also in other sectors.
In order to solve the above-mentioned problems, our research has found it necessary to set goals and objectives.
The purpose of the study was to substantiate the parameters of frontal plowing slope, which provides high-quality execution of the technological process in accordance with the agro-technical requirements with minimum energy consumption without furrow plowing, agrotechnical and energy performance of variable frontal forks.
The following results were achieved by performing the tasks identified in the study: a – humidity V=16–17 % and load conditions with elastic rods of 3 mm, 4 mm, 5 mm; b – humidity V=13–14 % and the diameter of elastic rods is 3 mm, 4 mm, 5 mm; c – humidity V=9–10 % and the diameter of the elastic rods is 3 mm, 4 mm, 5 mm.
The experiments were performed on lumps with different humidity conditions: 9–10 %, 13–14 % and 16–17 %. The speed of the installation was 1.0 m/s.
The recommended technology was to destroy soil fragments with a moisture content of 16–17 % at a vertical load of 400 N with 3, 4 and 5 mm elastic rods at 86.6, 81.5, 75.1 %, respectively, and the vertical load equal to 1,000 N – 94.4, 89.2, 81.2 %, respectively
Development of a technique for computer simulation of the stress state of the drive drum shell of a belt conveyor to optimize its design parameters
Authors: Jassinbekov Olzhas , Isametova Madina , Kaldan Gabit 
Published: May 2021

The paper considers the method of computer simulation of the stress-strain state of the drive drum shell in the NASTRAN integrated environment. Due to the complexity of determining stresses and deformations in the drum sections by the analytical method, it is proposed to solve this important problem using the numerical finite-element method. At the preliminary stage of computer modeling, a mechanical design scheme was developed, including a variable pressure that changes depending on the angle of rotation of the drum, the deterministic relations describing the variable force factors are based on the Euler ratio. It is also proposed to take into account the pressure from the variable friction force, which depends on the changing coefficient of adhesion of the belt to the drum.
As a result of the computer calculation, the equivalent Mises stresses of 65 MPa were determined, the safety factor was 4.2 and the components of the tangential stresses were determined using the stress tensor marker, the shear stress reached the level τ=16 MPa for fabric tape and τ=3.14 MPa for rubber tape. According to the results of the calculation, the dependence of the tangential stresses on the angle of rotation of the drum was constructed. A diagram of the change in the component of tangential stresses along the forming shell of the drum was constructed.
Analysis of stress-strain state allowed us to determine the factor of safety of the drum shell. Based on the analysis of equivalent stresses, it is proposed to further calculate the durability of the drum using the method of long-term fatigue. The computer calculation of shear stresses in the component allows choosing the rational parameters of the lining, based on such indicators as peel strength and break, as well as determining the angle 61° of the slab lining required to improve the reliability and traction ability of the pipeline
Influence of melt treatment parameters on the characteristics of modified cast iron in the metallurgical industry using data mining methods
Authors: Boldyrev Denis , Dema Roman , Latypov Oleg , Zhilenkov Anton , Emelianov Vitalii , Nedelkin Alexey 
Published: May 2021

A study of the effect of holding the cast iron melt at temperatures of 1,300, 1,450 and 1,600 °C for 20, 55 and 90 minutes on the structure and properties of cast iron in a liquid state and after crystallization was carried out. The studies were carried out on samples with a diameter of 30 mm; cast iron containing 3.61–3.75 % carbon, 1.9–2.4 % silicon, 0.03 % manganese, 0.081–0.084 % phosphorus, 0.031–0.039 % sulfur was poured into green-sand molds. The samples were cast from the original cast iron (unmodified), modified with ferrosilicon 75 GOST 1415-93 (FS75), rare-earth metals (REM) and together with the REM+FS75 complex. The structure of cast iron was investigated by optical metallography, electron microscopy and X-ray structural analysis. An increase in the holding temperature and time of the cast iron melt leads to an increase in its hardness. An increase in temperature at a short holding time leads to an increase in strength in the entire investigated temperature range (1,300–1,600 °С). Holding for 90 minutes at a temperature of 1,450 °C corresponds to an extremum, after which, with a further increase in temperature, a sharp drop in strength is observed. The change in the toughness of cast iron is characterized in a similar way
Devising a model of the airflow with dust particles in the intake system of a vehicle’s internal combustion engine
Authors: Saraiev Olexii , Khrulev Alexander 
Published: May 2021

This paper considers the mechanism of malfunction of internal combustion engines that implies the accelerated local wear of parts in individual cylinders as a result of uneven distribution of dust particles that pass through the air filter in the intake system.
In order to acquire quantitative data on the effect of the structure of the intake system on the redistribution of dust in engine cylinders, the two-phase flow of air with dust particles in the standard elements of the intake system was mathematically modeled.
ANSYS software package was used to solve the problem. A simulation technique was devised in which the airflow was first calculated to determine the boundary conditions for dust, after which the flow of air with particles was calculated. The calculations were carried out in a range of air velocities of 5‒20 m/s in branching channels with diversion angles of 45°, 90°, and 135° for the most characteristic particle sizes of 5‒30 µm. It has been estimated that dust particles deviate from the air streamlines by inertia and can slip through the lateral drain the stronger the larger particle size, diversion angle, and velocity of air.
The comparison of the simulation results with experimental data confirmed that in the intake system of some engines, due to uneven particle distribution, there is local abrasive wear in one or more cylinders, which can significantly reduce the resource. This paper shows the need to take into consideration the centrifugation and redistribution of dust in the intake systems during the design, modernization, expert studies to determine the causes of faults associated with faulty operating conditions, as well as to clarify the regulations for the maintenance of existing engines.
Development of temperature regime of storage of frozen black currants
Authors: Osokina Nina , Kostetska Kateryna , Herasymchuk Olena , Tkachenko Hennadii , Podpriatov Hryhorii , Pusik Ludmila , Falendysh Nataliy , Bobel Inna , Belinska Kristina 
Published: May 2021

The process of ice formation in the pericarp of black currant depends on the pomological variety, the degree of ripeness of the fruit, and the method of freezing.
During the slow and fast freezing of black currant, four ranges of fruit cooling temperatures are distinguished:
1) from the temperature of the fruit to the temperature of initiation of ice formation;
2) from the temperature of the front (initiation) of ice formation to the lowest possible temperature of the fetal mesocarp;
3) from the lowest possible temperature of the mesocarp to the lowest temperature of the fetal endocarp;
4) from the lowest possible endocarp temperature to fetal freezing temperature. Fast freezing boosts cooling, freezing and freezing from 37 min. (slow) up to 5.6 min. due to a halving of the temperature of initiation of ice formation, an increase of 1.3 times in the rate of heat extraction and an increase in the freezing temperature from –22...–24 °С (slow) to –20.8 °С.
It is scientifically substantiated that the temperatures of freezing fruits significantly change the general existing recommendations (not higher than –18 °С) regarding the storage conditions of black currant fruits: with quick freezing, not higher than –21 °С, with slow freezing, not higher than –24 °С.
The formation of the properties of black currant occurs during the growing season under various agro-climatic conditions and affects the parameters of ice formation indicators.
The marketable condition, quality and organoleptic characteristics of black currant fruits depend on the method of freezing. The advantages of fast freezing of black currant fruits in a quick-freezing chamber with forced air circulation at a speed of 1.5–2.5 m/s at a temperature of –30...–32 °С in comparison with slow freezing in freezers at a temperature of –20 have been established. ..– 22 °С.
Determining the effect of change in the gas injection timing on the performance indicators of the diesel engine operating in the diesel-gas cycle
Authors: Kovbasenko Serhii , Holyk Andrii , Simonenko Vatalii 
Published: May 2021

This paper reports a study into the fuel, economic, energy, and environmental indicators of the diesel engine operating in the diesel-gas cycle. It was established that the injection timing has a significant impact on the diesel engine indicators, in particular emissions of harmful substances with exhaust gases. The gas injection timing was investigated at crankshaft speeds n=1,300 rpm and n=1,600 rpm. At these crankshaft speeds, measurements were carried out at three different values of the injection timing. It has been determined that for each crankshaft speed of the diesel engine, the rational values of the injection timing of compressed natural gas are different. This is due to the time limits for supplying compressed natural gas to cylinders.
Bench motor tests were carried out to analyze the effect of change in the gas injection timing on the diesel engine performance indicators operating in the diesel-gas cycle. The diesel engine performance indicators were also determined during a diesel cycle and during a diesel-gas cycle. The analysis has established the effect of change in the injection timing on the concentrations of carbon monoxide, hydrocarbons, nitrogen oxides, and the smoke of exhaust gases under different speed and load modes of diesel engine operation. This effect manifests itself by a slight decrease in the concentration of carbon monoxide and hydrocarbons, by the increase in the concentration of nitrogen oxides (up to 30 %), and by a significant reduction in the smoke of exhaust gases (up to 90 %). The improvement of environmental indicators of the diesel engine has been confirmed when switching its operation to the diesel-gas cycle, by 10‒16 %, with similar fuel, economic, and energy indicators.
Thus, there are grounds to assert the importance of choosing and establishing the rational value for the injection timing of compressed natural gas, depending on the speed and load modes of diesel engine operating in the diesel-gas cycle.
Development of scientific and methodological approach to quantitative and qualitative assessment of intellectual property management in industrial enterprises
Authors: Raiko Diana , Cherepanova Viktoriia , Sylka Ihor , Podrez Olha , Fedorenko Irina 
Published: May 2021

The competitiveness, market value and income of an enterprise depend on the level of intellectual property management. Therefore, the aim of research is to develop, substantiate and test a scientific and methodological approach to a quantitative and qualitative assessment of the management of intellectual property of industrial enterprises.
The originality of the proposed approach is that on the basis of the concept of "management of intellectual property" a procedure for current management has been developed, the main stage of which is a quantitative and qualitative assessment. The assessment is based on the structural and logical model, which is built according to two criteria. The criteria make it possible to determine the current state of the use of intellectual property (intangible assets) – a quantitative assessment, and the prospect of further use (intellectual potential) – a qualitative assessment.
A quantitative assessment involves the calculation of indicators characterizing the state of assets, the dynamics of the impact on the market value of the enterprise, the profitability of production, which is proposed to be determined through the net cash flow from operating activities. A qualitative assessment is carried out in terms of components (information and investment, organizational and legal, economic, personnel and motivation), tools and relative indicators that characterize the intellectual potential of an industrial enterprise. The assessment is carried out using a general integral indicator, which is of practical importance, since it shows the existing level of intellectual property management and directions for improvement in the future.
The approbation of the scientific and methodological approach was carried out on the example of three Ukrainian coke-chemical enterprises (CJSC Avdeevka Coke Plant, CJSC Zaporozhkoks, CJSC Yuzhkoks) of the American association SUNCOKE ENERGY, INC and the Polish association J.S.W. S.A. Group. Empirical studies for the period from 2015 to 2019 made it possible to build a scale for assessing the level of intellectual property management according to the Harrington function
Biological features of blood lymphocytes of the primary patients with endometrial cancer
Authors: Domina Emiliia , Hrinchenko Olha 
Published: May 2021

The aim: to examine the radiosensitivity of chromosomes of T-lymphocytes in the blood of primary patients with endometrial cancer depending on the radiation dose. It was expected that the investigations would reveal a cytogenetic parameter as a predictor of radiosensitivity in non-malignant cells of patients exposed to curative irradiation.
Materials and methods. Blood samples from 20 primary patients and 30 conditionally healthy donors were examined. Peripheral blood T-lymphocytes culture test system with metaphase chromosome aberration analysis was used. X-ray test-irradiation was performed at G0-stage of the cell cycle in the dose range of 0.5–3.0 Gy.
Results. It was shown that the spontaneous level of chromosome aberrations in lymphocytes of primary patients before anti-tumour therapy is 7,82±0,33 aberrations/100 metaphases. This is more than 2-fold higher than the upper limit of average population index and approximately 6-fold higher than the data of own control. In our study during X-ray irradiation of cells cultures of patients, it was found for the first time that the total frequency of radiation-induced chromosome aberrations obeys the classical linear quadratic dose dependence with a predominance of linear component values; the frequency of radiation markers – also linear quadratic dose dependence, but with a predominance of quadratic component.
Conclusions. High specificity of T-lymphocyte chromosomes to exposure to ionizing radiation as well as strict dependence of chromosome aberration yield on exposure dose justify their use as predictors of radiosensitivity of healthy cells from the tumour environment. The revealed dependences of induction of chromosomal damage in T-lymphocytes of patients with endometrial cancer prove the need for a personalized approach to plan the course of radiation therapy
Resiliencia contra la pandemia de covid-19 en comunidades indígenas kichwa en la Amazonía ecuatoriana
Authors: Sirén Anders , Uzendoski Michael , Swanson Tod , Negrete Iván Jácome , Gualinga Emil Sirén , Tapia Andrés , Machoa Alex Dahua , Tanguila Aymé , Santi Eugenia , Machoa Dionicio , Andi Dixon , Santi Daniel 
Published: May 2021

Entre marzo – agosto de 2020, hubo un contagio muy generalizado de covid-19 en las comunidades indígenas Kichwa en la Amazonía ecuatoriana. Mostramos que el pico de contagio ya ha pasado y la mortalidad total ha sido notablemente baja. El pueblo Kichwa identifica su éxito en resistir la pandemia al uso generalizado de plantas medicinales.
KARACİĞER TRANSPLANTASYONUNDA MİKROKİMERİZM OLMADAN TOLERANS MÜMKÜN MÜDÜR?
Authors: ÇAĞ Murat , ÖZDEMİR Sevda Yeşim 
Published: May 2021

Amaç
Karaciğer transplantasyonu sonrası tolerans kavramı
son yıllarda giderek popülarite kazanmaktadır. Bu çalışmada
amacımız çok özenli parametrelerle seçilmiş
yaklaşık on yıllık bir seride düşük doz immünosupressif
kullanan bir grupta toleransın varlığını CD3+
hücrelerde mikrokimerizmin yokluğu ile kanıtlamaya
çalışmaktır.
Gereç ve Yöntem
Mikrokimerizm yokluğunu araştırma yöntemi; retrospektif
olarak donör kanlarından cross match yapılarak
DNA izolasyonunun ardından, mikrosatellit markerlarının
PCR ile amplifikasyonu ve dönör ve alıcı allellerinin
karşılaştırılması ilkesine dayanıyordu.
Bulgular
Postoperatif takiplerinde organ reddi ya da buna bağlı
komplikasyonları olmayan alkole bağlı sirozu olan
12 hastadan bir izogrup oluşturuldu. Bu hastalar immunsüpresif
olarak takrolimus ve mikofenolat mofetil
kullanıyordu ve ilaç kan düzeyleri 5 ng/l yani kabul
edilebilir sınırın altında idi. Çalışmamızda hiçbir hastamızda
kimerizm gözlemlemedik.
Sonuç
Biyokimyasal stabiliteyi koruyan mikrokimerizmin
yokluğu yani transplantasyona tolerans olması durumunda
immunsupressif tedavilerin kesilebilir olmasının
düşünülebilirliği gündeme gelmektedir.Böylelikle
immünsüpressif tedavilerin yan etkileri azalacak ve
hastalar böbrek yetmezliği, metabolik bozukluklar,
diyabet ve kanserlerin artmış riskinden korunacak,
dolayısı ile yaşam kalitesi artmış ve transplantasyon
sonrası kullanılan ilaçların ülke ekonomisine yükü
azalmış olacaktır.
To what extent do preservice teachers feel ready to teach? A case study in the Master’s Degree in Teaching in Secondary Education
Authors: Serrano Rodríguez Rocío , Pérez Gracia Elisa , Oteros Jose , Carpio Antonio J. 
Published: May 2021

Teacher-training programs around the world, and especially in Europe do not specify in detail the capacities that future professionals should acquire, so it brings about a great discussion among educators, researchers and teachers. The main objective of this study is to collect the impressions of future Secondary Education teachers as regards the competences attained during their studies. The self-evaluation of 353 students was carried out using a Likert-scale questionnaire made up by 13 variables gathered into three dimensions namely social competence, academic competence and personal competence. R Software, InfoStats and SPSS v. 25 software were used in order to analyze the data collected. Confirmatory factorial analyses and linear mixed modelling were applied to identify factors affecting the acquisition of competences. The students’ area of knowledge and their employment situation were key factors in the development of academic and social competences, while the personal dimension was affected only by the area of knowledge. These results obviously show that there are some competences whose level of development could be improved, and we have also identified some weaknesses in the development of certain competences. In addition, these data have allowed us to assess the strengths and weaknesses of the initial teacher-training curriculum.