bluuebunny/crossref_metadata_2025 huggingface dataset:
THE RELATIONSHIP OF DIABETES MELLITUS AND HYPERTENSION WITH MORTALITY IN COVID-19 PATIENTS
Authors: Nadzifah Yasmin Nihayatun , Hidajah Atik Choirul
Published: June 2022

Background: Coronavirus disease 2019 (COVID-19) can infect the human respiratory system and causes 6.93% of all deaths in East Java Province. Comorbid diabetes mellitus and hypertension can exacerbate COVID-19 patients. Purpose: This study aims to analyze the relationship between diabetes mellitus and hypertension with mortality in COVID-19 Patients in Lamongan District. Methods: This study used an analytic observational study with a cross-sectional design. The study population was patients diagnosed with COVID-19 and registered at Lamongan District Health Office from April to August 2020, as many as 412 patients. The study sample was 93 patients who were taken by simple random sampling. The dependent variable in the study was the incident of mortality in COVID-19 patients. The independent variables in the study were gender, age, hypertension, and diabetes mellitus. Data analysis was using the chi-square test. Results: The variables studied that had a relationship with mortality in COVID-19 patients were age ≥ 60 years (p = 0.02; PR = 3.23; 95% CI = 1.29 <PR <8.10) and diabetes mellitus (p = 0.03; PR = 3.20; 95% CI = 1.23 <PR <8.36). The variables studied that did not have a relationship with mortality in COVID-19 patients were gender (p = 0.30; PR = 1.72; 95% CI = 0.74 <PR <4.03) and hypertension (p = 0.72; PR = 1.37; 95% CI = 0.34 <PR <5.48). Conclusion: Age and diabetes mellitus are significantly associated with mortality in COVID-19 patients, but sex and hypertension are not significantly associated with mortality in COVID-19 patients.
The Effect of Red Dragon Fruit (Hylocereus polyrhizus) on ROS Plasma of Overweight Sprague Dawley Rats
Authors: Solehah Novia Zuriatun , Prayitno Adi , Pamungkasari Eti Poncorini
Published: June 2022

Red dragon fruit (Hylocereus polyrhizus) contains antioxidants, namely vitamin C, flavonoids, phenols, and betacyanins that can reduce or inhibit oxidative stress in the body. Excess body weight condition is associated with an increase in oxidative stress due to a decrease in antioxidants. This study was aimed to analyze the effects of red dragon fruit on the level of ROS (MDA) of overweight Sprague-Dawley rats. It used experimental analysis by using pre- and-posttest design with control group. A total sample of 30 male white Sprague-Dawley rats aged 8-12 weeks old with 150-200g of body weight were divided into 6 groups, namely: normal, negative control (KN), positive control (KP), red dragon fruit juice 3.5 g/200gBW (P1), overweight + dragon fruit juice 7 g/200gBW (P2), overweight + dragon fruit juice 10.5g/200gBW (P3) and were observed for 14 days. ROS levels were measured in the beginning and at the end of the intervention by using MDA markers with TBARs method. The results of MDA level measurements were 3.83 ± 0.13 in the KP group, 7.18 ± 0.27 in the P1 group, 5.30 ± 0.30 in the P2 group, and 4.35 ± 0.42 in the P3 group. The results of one-way ANOVA test showed a significant difference in MDA levels in all intervention groups compared to those of the normal and KN groups (p = 0.05). In conclusion, red dragon fruit intake can reduce ROS levels in overweight Sprague-Dawley rats.
Unhealthy Diet and Stress are Correlated with Premenstrual Syndrome in Adolescent Girls in Tangerang
Authors: Huwaida Dhea Zahra , Dewi Yulia Lanti Retno , Kusnandar Kusnandar
Published: June 2022

Adolescent girls is one of the age groups that are vulnerable to menstrual disorders, especially in the first year after menarche. Premenstrual syndrome (PMS) is a group of physical and emotional symptoms that emerge 7 to 14 days before menstruation and diminish once menstruation starts. This study was aimed to analyze the correlation between unhealthy diets and stress on premenstrual syndrome in adolescent girls. This study employed an observational study with a cross-sectional approach. The population of this study was all adolescent girls at State Junior High Schools in Tangerang City who aged 13-15 years. The sampling technique used cluster random sampling, consisting of 120 respondents. The data was collected through validated questionnaires, namely Food Frequency Questionnaire (FFQ), Perceived Stress Scale (PSS-10), and Shortened Premenstrual Assessment Form (SPAF). The obtained data were analyzed using Spearman statistical test. The results showed that there was a significant correlation between sweet foods (p = 0.039; r = 0.188), sweet drinks (p = 0.006; r = 0.247), salty foods (p = 0.026; r = 0.203), fatty foods (p = 0.000; r = 0.366) and fast food (p = 0.001; r = 0.313) and stress (p = 0.000; r = 0.564) on PMS. In conclusion, maintaining healthy diet and controlling stress is important to prevent and manage PMS among female adolescent.
Experiences of educated youth exposed to domestic violence: Social impact to their lives
Authors: Mas'udah Siti , Megasari Lutfi Apreliana , Doran Evan
Published: June 2022

The number of cases of domestic violence against women and children in Indonesia has escalated year by year. Various studies have revealed the impact of family violence on children, but few have sought to investigate the sociological lives of youth who have been exposed to domestic violence since childhood. This study aimed to reveal the experiences of educated youth who are exposed to domestic violence and its impact on them. This study used a qualitative method. The research informants were educated youth who had been victims of domestic violence and were currently students in the university. The results showed that children who were victims of exposure to violence had bad experiences throughout their lives. They recorded domestic violence from childhood to growing up. They believe that parents and families are parties that are unable to provide protection. In addition, exposure to violence also causes mental health disorders, poor psychological conditions, and thoughts of refusing to marry. This study concludes that exposure to domestic violence has a serious impact on children’s social development because from childhood to adulthood they grow up in a violence zone.
Degradation of democracy with the existence of a single candidate for regional head elections in Indonesia
Authors: Rohman Syaiful , Napang Marthen , Puspitasari Puspitasari
Published: June 2022

Regional head elections are part of the implementation of a democracy which is essentially indicated by political participation. The political elite at the central government also influences political competition in the regions. Every regional head election has to have a recommendation letter from the central board of the political party. The recommendation letter is a requirement for candidates for regent or mayor who will register to the General Election Commission (KPU). The general elections for regional heads are carried out to meet the demands of the community to elect their regional leaders directly with the spirit of democracy. Political elites often misuse democracy in pursuing power for personal or group interests so that a single candidate appears in the regional head elections. This study analyzes the relationship between the political elites and a single candidate using qualitative methods with descriptive analysis based on credible data sources. The results of this study stated that the political elite manipulate a significant role in gathering all-party support with a separate agreement so that a single candidate emerged in the regional head elections. This study concludes that the existence of a single candidate in the regional head elections results in a degradation in the democracy in Indonesia.
Politics of sickness: Political struggles over the meaning of “sick” in dealing with the COVID-19 pandemic in Indonesia
Authors: Bahar Adam Amin , Marijan Kacung , Mardiyanta Antun
Published: June 2022

In dealing with the COVID-19 pandemic, political actors in Indonesia tend to interpret “sick” in different ways. This study aims to discuss practices of political struggles over the meaning of “sick” in dealing with the COVID-19 pandemic in Indonesia. By using qualitative discourse analysis where data were mainly obtained from January to October 2020, this study found that political struggles over the meaning of “sick” in dealing with the COVID-19 pandemic in Indonesia were dominated by three major powers, namely the government, capitalist, and medical professionals. The meaning of “sick” given by these groups is not only different but also keeps changing from time to time, especially in certain political moments. This study found four important political moments which were closely related to the way these three groups of actors interpret the meaning of “sick” in the context of the COVID-19 pandemic. In one moment, “sick” was interpreted narrowly, while in another moment, “sick” was interpreted broadly. This study concludes that the struggle for the meaning of sick is an inherent practice in dealing with the COVID-19 pandemic in Indonesia. A further consequence is that the meaning of sick is not fixed as it is known so far but is more unfixed and contingent.
Challenges and problems in the recruitment of ad hoc workers of election management body at the local level: Evidence from Banyumas
Authors: Sugiarto Bowo , Akbar Andi Ali Said , Pratiwi Oktafiani Catur , Nurprojo Indaru Setyo , Perdani Titis
Published: June 2022

The prevailing national regulation on the recruitment of PPK, PPS, and KPPS staff sets forth that those temporary officers can be of service for only two periods of general election and cannot be involved afterwards. This regulation actually has positive aspect, but is not easy in its implementation. This article aims at examining the challenges and problems faced by the election management body at local level (Regency KPU) in preparing the human resource of ad hoc staff for the 2019 general election in Indonesia. This article was based on a qualitative research conducted in 2020 in Banyumas Regency, Central Java. This article shows that challenges that had to be faced by Regency KPU in the recruitment of ad hoc employees were the duration of screening and the way village leaders socialized the information regarding the recruitment. Whereas, the involvement of young generation and women as general election ad hoc workers in Banyumas was still low because of a number of factors, from know-how of general election to having lack information of the recruitment. This study concludes that actor’s action choice is limited by a number of matters, such as the path previously taken, rules regulating the agency, and social-political context.
A Proposal to Use Determinants of Annoyance in Wind Farm Planning and Management
Authors: van den Berg Frits
Published: June 2022

Wind energy in Europe is aimed to grow at a steady, high pace, but opposition from residents to local wind farm plans is one of the obstacles to further growth. A large body of evidence shows that local populations want to be involved and respected for their concerns, but in practice this is a complex process that cannot be solved with simple measures such as financial compensation. The visual presence and the acoustic impact of a wind farm is an important concern for residents. Generally environmental noise management aims to reduce the exposure of the population, usually based on acoustics and restricted to a limited number of sources (such as transportation or industry) and sound descriptors (such as Lden). Individual perceptions are taken into account only at an aggregate, statistical level (such as percentage of exposed, annoyed or sleep-disturbed persons in the population). Individual perceptions and reactions to sound vary in intensity and over different dimensions (such as pleasure/fear or distraction). Sound level is in fact a weak predictor of the perceived health effects of sound. The positive or negative perception of and attitude to the source of the sound is a better predictor of its effects. This article aims to show how the two perspectives (based on acoustics and on perception) can lead to a combined approach in the management of a wind farm aimed to reduce annoyance, not primarily of sound level. An important aspect in this approach is what the sound means to people: is it associated with the experience of having no say in plans, does it lead to anxiety or worry, is it appropriate? The available knowledge will be applied to wind farm management: planning as well as operation.
Pengembangan bahan ajar modul berbasis flipbook pada mata peajaran komputer akuntansi transaksi perusahaan dagang guna mendukung proses pembelajaran peserta didik XII AKL 1 di SMKN 1 Jombang
Authors: Nisfu Syabana Yusi , Susilowibowo Joni
Published: June 2022

Development research, whose purpose is to form new products. This research model in the form of 4D development includes Define, Design, Develope, and Disseminate by Thiagarajan, Dorothy S.Semmel &Melvyn I. Sommel. But at the dissemination stage (Dissemination) researchers have limited capabilities when carrying out the spread. Due to time and cost constraints. The subjects of this study include linguists, material experts, and graphicists with the type of method chosen is qualitative and quantitative. Quantitative data in the form of validity sheets that have been scored by validators in the form of percentages and qualitative data in the form of notes based on the product study of the study that is then described for improvement. Research instruments in the form of open and closed questionnaires containing research sheets and validity test sheets from material experts, linguistics, graffiti, and validators. And compiled based on the feasibility of teaching materials by BSNP (2014). Based on the study sheet produces analysis with qualitative descriptive while validation sheet produces analysis with quantitative descriptive. Techniques for data analysis are qualitative and quantitative. Descriptiveikualitative contains analysis sheets to study the stuffing of suggestions and criticisms from expert lecturers as a completeer of flipbook-based modules that have been developed. While descriptive quantitative contains validity sheets from experts. The main purpose of this study is to analyze how the development process and feasibility in this development researchers concluded that the development of flipbook-based module teaching materials in computer subjects accounting transactions of trading companies is declared feasible because it obtained 86%.
Pengembangan media pembelajaran berbasis camtasia studio pada mata pelajaran ilmu pengetahuan sosial (IPS)
Authors: Refia Putri DK , Sri Hariani Lilik , Walipah Walipah
Published: June 2022

This study aims to produce learning media products that are suitable for use in social science subjects (IPS) for social mobility material for class VIII students at SMPN 2 Wagir. This research includes research and development (R&D) with the Dick & Carey development model. The development of learning media is carried out in several stages, namely: needs analysis, material identification, student characteristics analysis, instructional objective analysis, product design/product manufacture, design validation, and product revision. This media development was validated by media experts, material experts, linguists, and field trials involving 32 students were carried out. Types of data obtained in the form of qualitative data and quantitative data. Data collection procedures used were observation, interviews, and questionnaires. Data analysis includes qualitative data analysis and quantitative data analysis. The results showed that the development of learning media based on Camtasia Studio in social science subjects (IPS) class VIII SMPN 2 Wagir was feasible to use. This is indicated by; the results of the media expert validation were included in the "very feasible" category with a score of 93%, the material expert validation results were included in the "very feasible" category with a score of 90%, the linguist validation results were included in the "very feasible" category with the score obtained by 95%. The results obtained in the field trial assessment were 88% (very good).
Compensation of Dynamic Phase Error in the Formation of Orthogonal Components of Input Signals in Microprocessor Protections
Authors: Romaniuk F. A. , Rumiantsev Yu. V. , Rumiantsev V. Yu. , Novash I. V.
Published: June 2022

In microprocessor protections of electric power systems, the controlled information parameters of input signals are determined using their orthogonal components. To form these components, digital Fourier filters which have inertia are most widely used. As a result, transient modes of orthogonal components formation are accompanied by the appearance of a dynamic error. It consists of dynamic amplitude and phase errors, which can significantly affect the functioning of the corresponding measuring elements and cause the possibility of their excessive triggering during external short circuits and slowing down the triggering during internal short circuits. The reduction of the influence of these factors on the behavior of measuring elements is ensured by the use of high-speed shapers to isolate orthogonal components, as well as by compensating for dynamic phase error. The proposed method of forming orthogonal components of a signal with compensation for dynamic phase error is based on obtaining orthogonal Fourier components, followed by determining from their samples the calculated components that coincide or are shifted in phase relative to the orthogonal Fourier components, respectively, in steady-state and transient modes. The resulting orthogonal components with minimal dynamic phase errors are calculated in accordance with samples of calculated orthogonal components and Fourier components. The efficiency of the proposed solution was evaluated by a computational experiment using a digital model implemented in the MATLAB-Simulink dynamic modeling environment. At the same time, both sinusoidal input signals and complex ones with an aperiodic component and higher harmonics were used as test actions. As a result of the studies carried out, it has been found that the proposed method of compensation for dynamic phase error in the formation of orthogonal components is workable and effective for both sinusoidal and complex input signals. The developed compensation method reduces the dynamic phase error of digital Fourier filters by three to four times.
Development of an Analytical Model for Determining the Magnetic Flux of Scattering through the Gears of the Stator of a Synchronous Electric Machine with a Fractional Gear Winding
Authors: Menzhinski A. V. , Panteleev S. V. , Malashin A. N.
Published: June 2022

The article presents a two-dimensional finite element model of the magnetic field of a magnetic system of a synchronous electric machine with fractional gear windings. The specific features of the distribution of magnetic fluxes (main effect, edge effect, scattering) in the magnetic system have been revealed and equivalent circuits of the magnetic circuit of the electric machine under study have been constructed at different positions of the stator gear relative to the rotor poles. The necessity of taking into account the edge effect and the dependence of the scattering flux through the gears of the stator on the coordinate of the rotor position has been justified, which is reflected in the analytical model that has been developed for determining the scattering flux through the gears of the stator of a synchronous electric machine with a fractional gear winding. The adequacy of analytical expressions was verified by means of a numerical method (finite element method). The resulting calculation error is due to the assumptions made when construсting an equivalent circuit of the magnetic circuit of the electric machine under study. A slight discrepancy between the results of the analytical calculation and the numerical experiment shows that the proposed model makes it possible to solve the problem of quantifying the magnitude of the magnetic flux scattering through the gears of the stator with high accuracy. In addition, this ensures an accurate determination of the influence of the geometric parameters of the magnetic circuit on the nature of the change in the periodic function of the scattering flow through the stator gear in the shortest time, which is of an obvious practical significance. The presented analytical model can be used in the process of optimizing a synchronous electric machine with fractional gear windings.
An Approach to Data Processing for the Smart District Heating System
Authors: Sednin A. V. , Zherelo A. V.
Published: June 2022

The article deals with the district heating systems transition to intelligent systems by developing a united information system and obtaining a high level of controllability of the entire system. During the implementation of automated control systems of district heating, a number of information tasks of the lower level are being introduced, including the data collection for thermal and hydraulic modes of operation for monitoring, operational management and analysis of the effectiveness. One of the problems of intelligent systems is data collection and its further storage and processing. Methods for data collection for real energy facilities are considered and the usage of multi-level system with the allocation of the upper level in the cloud storage has been proposed. In addition to the currently implemented data collection scheme in automated control systems, a generalized method of data acquisition with the introduction of duplicate streams has been proposed to ensure their integrity. The paper presents the approaches to identifying the collected data, ensuring the stability of the collection process, reliability of data storage and their integrity. Role-based security model with a dedicated single certification authority helps to protect data. Approaches to further processing of the collected data are shown, differing in the way of parallel data processing. The next stage of development is global monitoring systems that will be aimed to prompt response at all levels. The accumulated data will allow bringing the operating systems to a new level through the use of tools such as forecasting and simulation modeling, which will allow creating digital twins of heat supply systems. The proposed data collection system will perform forecasting and modeling at a higher level, and, as a result, help in the formation of more balanced management decisions.
Approximate Thermal Calculation of the Superheated Steam Condenser of Heat Pumps
Authors: Volodin V. I. , Zditovetskaya S. V.
Published: June 2022

A comparative analysis of the methods of approximate thermal calculation of the superheated steam condenser of the steam compression heat pump of the heat supply system is presented. The working substance of the heat pump and the condensing steam is the refrigerant R410a. When the single-zone method is applied, the condenser is calculated by one area with the inclusion of the heat of overheating in the heat of condensation and the use of the overheating coefficient. The two-zone method assumes the calculation of the condenser in two separate areas, viz. the cooling of superheated steam and its actual condensation. The approbation was carried out during a numerical study of a condenser of a low-temperature heat pump system for heating and hot water supply, with a heat exchange surface in the form of a spiral coil pipe in a pipe immersed in a heated liquid. In the first approach, the flow rate and temperature of the heated water are limited by the saturation temperature of the condensing refrigerant, regardless of the flow pattern of the working media. The method of two-zone calculation of the superheated steam condenser with a counter-current or cross-counter-current flow scheme of working media makes it possible to obtain real results of the temperature of the heated water that exceeds the temperature of the saturated refrigerant vapor, taking into account the flow rate of the heated water. In this case, the wall temperature in the cooling area is higher than the saturation temperature, and during condensation it is lower, which further confirms the adequacy of the presented technique. The use of a two-zone technique with a separate averaging of the physical properties of the working media in the areas of superheated steam and condensation cooling, as well as temperature pressures, provides a more accurate value of the heat exchange surface, which in the case under consideration is reduced to 20%. Based on the conducted studies, it is recommended to use a two-zone technique that makes it possible to obtain reliable data on the parameters of the superheated steam condenser.
Investigation of the properties of protective compositions contacting with acid–containing waste gases formed during the production of secondary aluminum in CAT‑0,15, CAT‑0,5 and CAT‑2,5
Authors: Panasyugin A. S. , Tsyganov A. R. , Kulinich I. L. , Masherova N. P. , Dolgiy L. P.
Published: June 2022

The paper analyzes the mineral acid vapors formation and their interaction with protective coatings based on bentonite clays, periclasite and shungite. A theoretical assessment of the acid vapor in the exhaust gases amount was carried out taking into account the performance of furnaces. Thermodynamic probability of acid vapor formation was calculated depending on the melting conditions for different types of melting units, the interaction of acid vapor with the components of protective coatings based on bentonite clays, periclasite and shungite was estimated.
Mechanisms of phase transformations in iron
Authors: Marukovich E. I. , Stetsenko V. Yu. , Stetsenko A. V.
Published: June 2022

Gibbsmolarvolumetricenergyandiron boundary molar energy are determined depending on temperature. It has been shown that phase transformations in iron occur under thermodynamically equilibrium conditions. The iron phase microcrystals are dendrites. Crystallization of the iron melt is a nanostructural process. Iron recrystallization has been shown to be a largely diffuse process.
Metal consumption rates in rolling production
Authors: Kashko S. A.
Published: June 2022

The rationing of material resources is understood as the process of determining the amount of their consumption necessary for the normal production process. The regulatory framework includes a set of norms and standards applied at the enterprise for planning and analytical purposes. The consumption rate is the maximum permitted planned amount of raw materials, materials for the production of a unit of production (work) of established quality in the planned production conditions. The consumption standard is the specific consumption of raw materials or materials attributed to a unit of mass, area, length, volume, which is a component of the consumption standards. The multidimensional nature of technological processes, as well as the multidirectional application of consumption standards determine their classification by the degree of enlargement of the object of rationing (individual; group); by the degree of enlargement of the nomenclature of materials (specific in the nomenclature for production; consolidated for homogeneous types of raw materials, materials for the production of a product or a nomenclature group of products); period of validity. This article presents methods for calculating individual specific metal consumption rates in the production of rolled products at the rolling mill 370/150 of OJSC «BSW – Management Company of Holding «BMC».
Structural aspects of deformation hardening with repeated drawing low carbon wire
Authors: Fetisov V. Р.
Published: June 2022

While repeated drawing of low carbon wire, a decrease in the grain size of ferrite reduces the parameters of deformation hardening in the initial field of deformations with parabolic hardening and increases in the field of substructural hardening with large and extra‑large total compressions. The transition from large to super‑large total deformations goes along with the development of dynamic return processes that reduce the rate of deformation hardening. Preliminary thermal softening of cold‑formed wire increases the strength gain during subsequent drawing and can be used to increase the total compression of the wire rod before intermediate heat treatment.
Modeling of the process of heating of chip‑powder dispersions of ferrous metals in the pass‑through muffle furnace of hot briquetting. Message 1
Authors: Dyakonov O. M. , Litvinko A. A. , Sereda V. Yu.
Published: June 2022

The description of the device and principle of operation of the continuous muffle furnace for hot briquetting of chip‑powder dispersions of ferrous metals is given. A distinctive feature of this device is the presence of two systems of gas‑flame and induction heating, as a result of which the achievement of the specified charge heating temperature is guaranteed with the complete removal of the liquid phase. The oil component of the coolant is used to create a protective hydrocarbon atmosphere that provides non‑oxidizing heating of the metal, as well as to obtain a carbon coating, which, in addition to protective functions, acts as a lubricant in the hot briquetting process. Subsequent combustion of oil vapors in the furnace leads to significant savings in natural gas. A furnace built according to this principle has the smallest dimensions and the highest technical and economic characteristics.

The simulation of the chip heating process in the zone of loading into the furnace is carried out. The dependences of the temperature of the chips at the outlet of the screw feeder on the temperature of the flue gases at the inlet for the mass fraction of coolant in the chips of 10 % and various fractions of oil are obtained. It has been established that during the heating of the chips in the loading zone, phase transformations of the coolant do not occur, the charge heating temperature does not exceed 100 °C.
Aluminum composites based on high‑strength alloy B95 treated with activated dispersed particles
Authors: Volochko A. Т. , Kovalko M. S. , Podbolotov K. B. , Wang Yangwei , Wang Haiyun
Published: June 2022

The paper presents the results of studies on the production of composites during the processing of aluminum melt based on high‑strength alloy B95 activated dispersed particles of nitrides (AlN, Si3N4, TiN), carbides (SiC, TiC), nanostructured carbon (fullerene carbon black), nitrogen‑containing components (glycine C2H5NO2, carbamide CH4N2O). The evaluation of the strength properties of the obtained composites from the activation modes of the charge with dispersed particles and the modes of heat treatment of the material is given. The possibility of increasing the strength characteristics of the casting composite by 15–20 % due to additional mechanical activation of the charge and achieving, after heat treatment, the compressive strength of 900–1050 MPa, hardness of 150–160 NV, elastic modulus of 20–25 GPa is shown.
The effect of ion‑plasma nitriding on the enduring quality and the nature of changes in the surface roughness of titanium alloys VT1‑0, VT6 and OT4‑1
Authors: Drobov A. N. , Bosyakov M. N. , Pobol I. L
Published: June 2022

The effect of the temperature of the ion‑plasma nitriding process on the enduring quality of the resulting hardened layers on titanium VT1‑0 and titanium alloys VT6 and OT4‑1 and the effect of ion‑plasma nitriding on the change in the Ra parameter of the surface roughness of titanium samples is investigated. It is defined that ion‑plasma nitriding leads to a significant increase in the enduring quality of the titanium alloys under study. The depth of the enduring quality groove in untreated samples of titanium VT1‑0, alloys VT6, OT4‑1 was 11, 7 and 10 microns, respectively, whereas in samples after ion‑plasma nitriding, the wear groove had a depth of 1.9, 0.9, 2.1 microns. It was revealed that when the initial roughness of the processed samples is more than Ra 0.1 microns after ion nitriding, the roughness index Ra, one of the key components of surface quality, decreases.
Soil Liquefaction Problems in the Foundations Hydraulic Structures
Authors: Morgunov K. P. , Kolosov M. A.
Published: June 2022

An analysis of the probability and conditions for the occurrence of soil liquefaction at the base and in the vicinity of hydraulic structures is presented in the paper. As a rule, hydraulic structures are erected in the valleys of watercourses, the structure of the soil in which contributes to the occurrence of liquefaction processes. These soils are fine-grained, 

non-cohesive, usually consisting of fine- and medium-grained or silty sands, sandy loams, interspersed with layers of loams. Massifs under pressure hydraulic structures are quite water-saturated. Soil liquefaction occurs as a result of the destruction of structural bonds between particles in water-saturated dispersed soils under the action of stresses of various types. An external dynamic or static load applied to a water-saturated massif composed of weak, finely dispersed soils can lead to a complete or partial loss of soil bearing capacity and its transition to a fluid state. The magnitude of soil resistance to shear is determined by the degree of its water saturation; at a moisture content of about 20 %, the angle of repose of sandy soils is significantly reduced. The restoration of the strength properties of soils is prevented by the pore water pressure, the process of compaction (consolidation) of the soil mass occurs after the water is squeezed out of the pores, the flow time of which depends on the filtration properties of the massif. Liquefaction of soils leads to a disruption in the normal functioning of a hydraulic structure, the creation of emergency situations. The paper provides examples of accidents at hydraulic structures in Russia caused by liquefaction phenomena. It is noted that the main directions of protecting the structures of hydraulic structures from dangerous liquefaction are to prevent the possibility of liquefaction and the reduction of its harmful effects.  In this regard, several methods are considered – compaction and strengthening of soils at the base of structures; filtering surcharge device using geotextiles and geogrids; creation of an effective drainage system.
Improvement of Calculation Technique for Flexible Orthotropic Plates on Elastic Base. Part 1: Calculation Theory
Authors: Kozunova O. V.
Published: June 2022

The paper considers a rectangular orthotropic insulated slab on an elastic foundation, modeled by an elastic homogeneous isotropic layer rigidly connected to a non-deformable foundation. Elastic and nonlinear calculations of this plate opening. The calculation of a flexible orthotropic slab on an elastic foundation in a nonlinear formulation is carried out iteratively by the method of B. N. Zhemochkin. To determine the coefficients of the canonical equations and free terms, a mixed method of structural mechanics was used. The deflections of a slab with a pinched normal in the main system of the mixed method due to the action of a concentrated force are determined by the Ritz method when the deflections are represented as a power polynomial in a new original expression, which is proposed by the author for the first time in the studies. This expression satisfies not only the boundary conditions of the pinched slab in terms of displacements, but also the biharmonic equation. In nonlinear calculations, when finding the variable (secant) stiffness for the Zhemochkin section,  at each iteration, the “stiffness – curvature” dependence is used for each of the X and Y directions, approximated by a nonlinear function, the nature of the dependence of which graphically indicates the nonlinear-elastic operation of the orthotropic plate and its deformation taking into account crack formation and crack opening. The algorithm for the above solution is implemented using the Wolfram Mathematica 11.3 computer program.
Electromagnetic Waves in Maxwell’s Theory
Authors: Nevdakh V. V.
Published: June 2022

The description of a plane traveling electromagnetic wave existing in the physical literature by identical solutions of wave equations for the strengths of electric and magnetic fields is physically incorrect, since such solutions contradict the physical meaning of Maxwell’s equations and violate the energy conservation law. The paper gives a physically correct 

description of electromagnetic waves in the framework of Maxwell’s theory. New solutions of Maxwell’s wave equations for traveling electromagnetic wave are proposed, in which the strength of its electric and magnetic components change in time with shifts of a quarter of the period and a quarter of the wavelength along coordinate. The solutions describe a traveling electromagnetic wave, in which the energy of the electrical component is sequentially converted into the energy of the magnetic component and vice versa; the total energy density of the lossless wave remains constant in space at any time; the mutual orientation of the intensity vectors of the electric, magnetic fields and phase velocity changes from a left-handed three to a right-handed three every quarter of the wavelength; the energy flux density of the traveling wave is described by the Umov vector. It is shown that the formation of a standing electromagnetic wave does not require the loss of half a wave of one of the components of the wave reflected at the interface between the media.  In a standing wave, the total energy density remains constant in time, but it is a function of coordinates: there are points in space where the total energy density of the wave at any time is zero – these are nodes, and there are points where it has a maximum value – these are antinodes. Due to the inhomogeneity of the distribution of the total energy density of the wave in space, a standing electromagnetic wave cannot be considered as a harmonic oscillator, but a lossless traveling electromagnetic wave can.
Application of Flow Theory Relations for Solving Problems of Steady-State Crack Growth
Authors: Hundzina M. A. , Yuhnovskaya O. V.
Published: June 2022

To represent local displacement fields in the problem of the steady-state growth of a crack, which contains a plate of incompressible material, the strain intensity formula is used in the form of a polynomial of the second degree. The case of plane deformation for an elastoplastic material is considered. The solution is obtained by the method of asymptotic expansions. Numerical analysis is carried out for the first term of the expansion. The aim of the work is the process of obtaining analytical solutions to applied problems of the theory of plasticity: finding the components of stress and strain tensors. The paper considers a variant of the method of asymptotic expansions and its application for the problem of the distribution of the stress-strain state in an elastoplastic specimen with a crack. The method of asymptotic expansions has some advantages over the numerical approach in studying the stress-strain state in the vicinity of a crack. It allows to establish exact quantitative relationships between the radial component, the angle, and the components of the stress and strain tensor. Another advantage of this method is the possibility of compiling the mechanical characteristics of an object at the design stage. A system of differential equations has been developed that contains V0 and its derivatives up to the third order. An example of stress distribution in the vicinity of a crack tip in a steel sample, obtained in a computer system by a numerical method, is given. The deformation diagram has been constructed for the material steel 40. The research results can be used to construct stress and strain fields in the vicinity of a crack, as well as to predict the further direction of crack development.
Economic Fundamentals for Development of International Road Freight Transportation Logistics in the Republic of Belarus under Coronavirus Pandemic
Authors: Ivut R. B. , Zinevich A. S.
Published: June 2022

The paper considers an issue of international logistics development in Belarus under world coronavirus COVID-19 pandemic. As a result of analytical reviewing of the up-to-date scientific literature on the problem under study, the expediency is stated for highlighting the logistics of international road freight transportation as an independent area of theoretical research and practical activity. Further development of international road freight transportation logistics in the Republic of Belarus requires a complex economic analysis of the present state and dynamics of the international road freight transportation market, which is the main purpose of the present publication. The paper contains the results of the analysis of the market for international and transit freight road transportation. Separately the paper points out the dynamics of transit goods transportation segment in this market in response to the reorientation of international freight flows. Interconnection is shown between the volume indices of international road freight transit through the territory of Belarus and the dynamics of goods import to the Russian Federation from the EU countries. For the first time a proposal is given to use the methodological tools of systemmatrix diagnostic analysis for investigation of the macroeconomic development process of international road freight transit logistics. The author’s set of initial parameters for the analysis has been formed, and its results are presented on the basis of the data of the State statistical reporting form for 2019–2020. A suggestion is given for joint usage of system-matrix diagnostic tools in combination with author’s methodology for assessing the effectiveness of transit (international) freight transportation while evaluating the competitiveness of economic entities in the industry. The most typical trends of the market development in the short term are stated, taking into account the more complicated market conditions.
Digital technology for spectral analysis of oscillation parameters
Authors: Gulaj A. V. , Zajcev V. M.
Published: June 2022

Performing the Fourier analysis of the harmonic composition of oscillations is an effective approach to the study of vibration processes in machines and mechanisms. This method of express control remains relevant and highly demanded in the acoustic diagnostics of machines due to its relatively high informativeness. The expansion of its analytical capabilities is implemented by introducing additional means for digital processing of vibration signals, including smart systems. The objective of this work consists in creating a digital method for spectral analysis of vibration signals, the implementation of which would be possible with the use of smart devices. This work presents a method of polyharmonic approximation of the parameters of the signals reflecting oscillatory processes in machines based on the additive combinations of sinusoidal functions. The technology of truncation of the time discretised decomposition of the above signals into a Fourier series is implemented using the Rayleigh theorem and the Lyapunov – Parseval equality. The distortion of the frequency spectrum of oscillations is eliminated by suppressing its side lobes using window filters. To compare the efficiency of different windows, the following special parameters are used: width of the main lobe of the frequency spectrum; coefficient of relative expansion of the main lobes; maximum relative level of side lobes; coefficient of relative attenuation of signal energy. In so doing, the windows of Hanning, Nuttall, Hamming, Barlett were considered, and the parameters of a rectangular window were taken as basic values. The limitations of the digit capacity of analogto-digital signal converters depending on the required accuracy of maintaining the energy balance when truncating the discrete Fourier expansions have been determined. An example of implementation of the digital technology of spectral analysis of the parameters of oscillatory processes is given.
Exact and greedy algorithms of allocating experts to maximum set of programmer teams
Authors: Prihozhy A. A.
Published: June 2022

The allocation of experts to programmer teams, which meet constraints on professional competences related to programming technologies, languages and tools an IT project specifies is a hard combinatorial problem. This paper solves the problem of forming the maximum number of teams whose experts meet all the constraints within each team. It develops and compares two algorithms: a heuristic greedy and exact optimal. The greedy algorithm iteratively solves the set cover problem on a matrix of expert competences until can create the next workable team of remaining experts. The paper proves that the allocation greedy algorithm is not accurate even if the set cover algorithm is exact. We call the allocation algorithm as double greedy if the set cover algorithm is greedy. The exact algorithm we propose finds optimal solution in three steps: generating a set of all non-redundant teams, producing a graph of team’s independency, and searching for a maximum clique in the graph. The algorithm of generating the non-redundant teams traverses a search tree constructed in such a way as to guarantee the creation of all non-redundant teams and absorbing all redundant teams. The edges of the non-redundant team independency graph connect teams that have no common expert. The maximum clique search algorithm we propose accounts for the problem and graph features. Experimental results show that the exact algorithm is a reference one, and the double-greedy algorithm is very fast and can yield suboptimal solutions for large-size allocation problems.
Analysis of Temporal and Spatial Evolution Characteristics of Land Subsidence in Western Songnen Plain Using Multisource Remote Sensing
Authors: Zheng Lianjing , Wang Qing , Wang Zeyu , Wang Fengyan , Cao Chen
Published: June 2022

The exploitation of underground fluid is an important factor leading to land subsidence. The effects of mining depth, frequency, and mode on land subsidence are also different. The objective of this study was to develop a multisource method—including optical remote sensing interpretation, Interferometric Synthetic Aperture Radar (InSAR) technology, and unmanned aerial vehicle (UAV)—to reveal the long-term temporal and spatial evolution law of subsidence characteristics driven by groundwater and oil extraction, as well as to reveal the formation mechanism and seasonal response law of land subsidence under the action of different driving factors. In this paper, we select the western region of Jilin Province located in Songnen Plain as the study area. The subsidence funnels in the study area are distributed in a porphyritic manner, and the distribution of the subsidence funnels has a certain correlation with the distribution of the pumping wells. In farmland areas, the subsidence is mainly caused by pumping groundwater. The annual land subsidence rate in the study area is -3.14 mm/a, and the maximum deformation rate in the study area is -22.05 mm/a. The subsidence is affected by the season, shown by the fact that it rises in the dry season and decreases in the rainy season. The subsidence in the west of Songnen Plain is caused by oil pumping and groundwater pumping, and groundwater pumping is dominant. The exploitation of underground fluid transfers the pressure borne by water or oil to the soil skeleton so as to increase and consolidate the effective stress of the soil layer and lead to land subsidence. The continuous observation of the surface in the western area of Songnen Plain is helpful to guide the safe production of agriculture and industry and ensure the smooth development of local industry and agriculture.