bluuebunny/crossref_metadata_2025 huggingface dataset:
Elucidation of an essential function of the unique charged domain of Plasmodium topoisomerase III
Authors: Bansod Shephali , Bung Navneet , Singh Priyanka , Suthram Niranjan , Choudhury Himashree , Roy Arijit , Bulusu Gopalakrishnan , Bhattacharyya Sunanda
Published: November 2020

Topoisomerase III (TopoIII) along with RecQ helicases are required for the resolution of abnormal DNA structures that result from the stalling of replication forks. Sequence analyses have identified a putative TopoIII in the Plasmodium falciparum genome (PfTopoIII). PfTopoIII shows dual nuclear and mitochondrial localization. The expression and association of PfTopoIII with mtDNA are tightly linked to the asexual replication of the parasite. In this study, we observed that PfTopoIII physically interacts with PfBlm and PfWrn. Sequence alignment and domain analyses have revealed that it contains a unique positively charged region, spanning 85 amino acids, within domain II. A molecular dynamics simulation study revealed that this unstructured domain communicates with DNA and attains a thermodynamically stable state upon DNA binding. Here, we found that the association between PfTopoIII and the mitochondrial genome is negatively affected by the absence of the charged domain. Our study shows that PfTOPOIII can completely rescue the slow growth phenotype of the ΔtopoIII strain in Saccharomyces cerevisiae, but neither PfY421FtopoIII (catalytic-active site mutant) nor Pf(Δ259–337)topoIII (charged region deletion mutant) can functionally complement ScTOPOIII. Hydroxyurea (HU) led to stalling of the replication fork during the S phase, caused moderate toxicity to the growth of P. falciparum, and was associated with concomitant transcriptional up-regulation of PfTOPOIII. In addition, ectopic expression of PfTOPOIII reversed HU-induced toxicity. Interestingly, the expression of Pf(Δ259–337)topoIII failed to reverse HU-mediated toxicity. Taken together, our results establish the importance of TopoIII during Plasmodium replication and emphasize the essential requirement of the charged domain in PfTopoIII function.
KRASG12C inhibitor: combing for combination
Authors: Chakraborty Atanu
Published: November 2020

Oncogenic mutation in KRAS is one of the most common alterations in human cancer. After decades of extensive research and unsuccessful drug discovery programs, therapeutic targeting of KRAS mutant tumour is at an exciting juncture. The discovery of mutation-specific inhibitors of KRASG12C and early positive findings from clinical trials has raised the hope of finally having a drug to treat a significant segment of KRAS mutant cancer patients. Crucially, it has also re-energized the RAS field to look beyond G12C mutation and find new innovative targeting opportunities. However, the early clinical trial data also indicates that there is significant variation in response among patients and that monotherapy treatment with KRASG12C inhibitors (G12Ci) alone is unlikely to be sufficient to elicit a sustained response. Understanding the molecular mechanism of variation in patient response and identifying possible combination opportunities, which could be exploited to achieve durable and significant responses and delay emergence of resistance, is central to the success of G12Ci therapy. Given the specificity of G12Ci, toxicity is expected to be minimal. Therefore, it might be possible to combine G12Ci with other targeted agents which have previously been explored to tackle KRAS mutant cancer but deemed too toxic, e.g. MEK inhibitor. Ongoing clinical trials will shed light on clinical resistance to G12C inhibitors, however extensive work is already ongoing to identify the best combination partners. This review provides an update on combination opportunities which could be explored to maximize the benefit of this new exciting drug.
Distribution transformer relocation problem: an integer programming solution
Authors: Azimi Hosseini Kamyar , Hajiaghapour‐Moghimi Mehran , Hajipour Ehsan , Vakilian Mehdi
Published: November 2020

The short‐term expansion planning of the private utilities, as well as the emerging technologies such as photovoltaic panels (PVs), plug‐in hybrid electric vehicles (PHEVs), cryptocurrency mining, and storage elements spread, make the long‐term load estimation of distribution transformers (DTs) noticeably imprecise. In response, the number of overload and underload transformers is growing in recent years. The utilities normally analyse the loading of their DTs annually to determine the DTs, which should be replaced. It is a common practice for utilities to relocate these DTs to reduce the investment needed to purchase new transformers. Therefore, the utility needs a systematic algorithm to determine the optimal schedule to relocate/replace the DTs with minimum required time and cost. This paper introduces a two‐stage procedure to obtain the optimal schedule to replace DTs. In the proposed algorithm, the maximum permitted number of work‐hours per day for field workers is considered, which converts the problem to a daily‐task based optimisation problem. Also, an useful life investigation of the in‐service DTs is considered in the relocation problem. A real case study in Qom province, Iran, has been studied to prove the effectiveness of the proposed algorithm.
Research on fault current limitation and active control for power electronic transformer in direct current grid
Authors: Zhuo Chaoran , Zhang Xiaotian , Zhang Xiong , Yang Xu
Published: November 2020

Due to the low impedance of DC (Direct Current) power transmission line, short‐circuit current has a very high increment speed, which causes problems as difficulty in current limitation method. This paper proposes a new method to realize the current‐limiting control of short‐circuit current by using active control of power electronic transformer. The method improves the topology of dual active bridge modules that contribute the DC transformer, and installs an IGBT (Insulated Gate Bipolar Transistor) switch in reverse direction on supporting capacitor branch of each module to control the capacitor on or off, which can guarantee the storage energy within the capacitor will not release in initial stage in case of DC short circuit fault happen. Therefore, there is no large inrush current flow out. Furthermore, combined with the requirements of current tracking control during low‐voltage ride‐through, the transformer output current under short‐circuit condition is actively controlled in order to meet the needs of renewable energy power generation equipment. Finally, the simulation and hardware‐in‐the‐loop experiments verify the correctness of this method.
Increasing distributed generation hosting capacity in distribution systems via optimal coordination of electric vehicle aggregators
Authors: Quijano Darwin A. , Melgar‐Dominguez Ozy D. , Sabillon Carlos , Venkatesh Bala , Padilha‐Feltrin Antonio
Published: November 2020

This work presents a novel strategy, designed from the distribution system operator viewpoint, aimed at estimating the hosting capacity in electric distribution systems when controllable plug‐in electric vehicles are in place. The strategy seeks to determine the maximum wind‐based distributed generation penetration by coordinating, on a forecast basis, the dispatch of electric vehicle aggregators, the operation of voltage regulation devices, and the active and reactive distributed generation power injections. Different from previous works, the proposed approach leverages controllable features of electric vehicles taking into account technical electric vehicle characteristics, driving behaviour of electric vehicle owners, and electric vehicle energy requirements to accomplish their primary purpose. The presented strategy is formulated as a two‐stage stochastic mixed‐integer linear programming problem. The first stage maximises the distributed generation installed capacity, while the second stage minimises the energy losses during the planning horizon. Probability density functions are used to describe the uncertainties associated with renewable distributed generation, conventional demand, and electric vehicle driving patterns. Obtained results show that controlling the power dispatched to electric vehicle aggregators can increase the distributed generation hosting capacity by up to 15% (given a 40% electric vehicle penetration), when compared to an uncontrolled electric vehicle approach.
Moisture‐dependent interface and bulk behaviour of space charge in DC‐stressed oil‐impregnated pressboard insulation
Authors: Zhou Guiyue , Wu Jiandong , Che Lu , Yin Yi
Published: November 2020

In this paper, the effect of moisture on the charge behaviour in oil‐impregnated pressboard is analysed based on the characteristics of the interface and the bulk. Space charge behaviour and infrared spectra are acquired from a sample with a high moisture content of 1.92% and another with low moisture content of 0.13%. The results show that a greater number of hydrogen bonds form in the high‐moisture sample. The threshold fields of charge injection are 1 and 0.6 kV/mm in the low‐ and high‐moisture samples, respectively. The dynamic charge transport in bulk is significantly accelerated by moisture. The drop in the injection barrier at the interface and the accelerated transport of charge in bulk in the high‐moisture sample may be associated with the mediating effect of a water layer at the interface and the lower trap energy in bulk caused by the hydrogen bonds, respectively. The combined changes in the interface and the bulk led to the dominant position of negative charges inside the high‐moisture sample, regardless of the distribution area or the charge amount.
Domain‐invariant adversarial learning with conditional distribution alignment for unsupervised domain adaptation
Authors: Wang Xingmei , Sun Boxuan , Dong Hongbin
Published: November 2020

Unsupervised domain adaption aims to reduce the divergence between the source domain and the target domain. The final objective is to learn domain‐invariant features from both domains that get the minimised expected error on the target domain. The divergence between domains which is also called domain shift is mainly between the distributions of domains' samples. Additionally, the label shift is also a tricky challenge in domain adaptation. In this study, domain‐invariant adversarial learning with conditional distribution alignment is proposed to alleviate the effect of domain shift with label shift. To obtain the domain‐invariant features, the proposed method modifies adversarial auto‐encoder architecture and performs semi‐supervised learning to enlarge the inter‐class discrepancy. The marginal distribution is aligned in the adversarial learning process of extracting domain‐invariant features. Meanwhile, the label information is incorporated in this way to align the conditional distribution. The proposed work also theoretically analyses the generalisation bound of the proposed model. Finally, the proposed method is evaluated based on several domain adaptation tasks, including digit classification and object recognition, and achieves state‐of‐the‐art performance.
Human‐like evaluation method for object motion detection algorithms
Authors: Guzman‐Pando Abimael , Chacon‐Murguia Mario Ignacio , Chacon‐Diaz Lucia B.
Published: November 2020

This study proposes a new method to evaluate the performance of algorithms for moving object detection (MODA) in video sequences. The proposed method is based on human performance metric intervals, instead of ideal metric values (0 or 1) which are commonly used in the literature. These intervals are proposed to establish a more reliable evaluation and comparison, and to identify areas of improvement in the evaluation of MODA. The contribution of the study includes the determination of human segmentation performance metric intervals and their comparison with state‐of‐the‐art MODA, and the evaluation of their segmentation results in a tracking task to establish the impact between performance and practical utility. Results show that human participants had difficulty with achieving a perfect segmentation score. Deep learning algorithms achieved performance above the human average, while other techniques achieved a performance between 88 and 92%. Furthermore, the authors demonstrate that algorithms not ranked at the top of the quantitative metrics worked satisfactorily in a tracking experiment; and therefore, should not be discarded for real applications.
Adaptive trainable non‐linear reaction diffusion for Rician noise removal
Authors: Yang Huan , Li Hongwei , Duan Yuping
Published: November 2020

Rician noise reduction is an essential issue in magnetic resonance imaging (MRI). Recently, learning‐based methods have achieved great success in dealing with image restoration problems, which provide fast inference and good performance. One limitation of these methods, however, is that the training procedure is usually noise‐level dependent, i.e. the trained models are bound to a specific noise level and lack the ability to automatically adapt to different noise levels. In this study, the authors propose a variational model for Rician noise removal by integrating a noise adaption function into the field of experts image prior, which can adapt to different noise levels. Instead of directly solving the energy minimisation problem, the authors unroll the gradient descent step of the energy functional for several iterations, the time‐dependent parameters of which can be learned through a supervised training process. The authors call this methodology as the noise adaptive trainable non‐linear reaction–diffusion model. The proposed methodology is robustness against noise level changing and noise distributions. Experimental results over ‐, ‐ and PD‐weighted MRI data set demonstrate that the proposed model can achieve superior performance compared with other methods in terms of both the peak signal‐to‐noise ratio and the structural similarity index.
TSDCN: Traffic safety state deep clustering network for real‐time traffic crash‐prediction
Authors: Li Haitao , Bai Qiaowen , Zhao Yonghua , Qu Zhaowei , Xin Wang
Published: November 2020

Traffic safety state clustering has always been the focus of traffic safety research and the foundation of real‐time crash potential prediction. How to mine effective latent crash risk information and improve clustering effect are the goals and difficulties of traffic safety state clustering task. The conventional methods adopt independent feature extraction and clustering processing, which leads to mismatch problems and decrease clustering effect. To deal with the problems, a novel traffic safety state deep clustering network (TSDCN) is proposed. TSDCN integrates the feature extraction and clustering into an end‐to‐end deep hybrid network. A custom autoencoder is constructed to extract expressive risk feature and iteratively optimize clustering effects and feature extraction using a deep clustering layer. The three‐stage multitask strategy is designed to joint‐adjust shared network parameters and ensure convergence at different stages. The comparative experiments show the TSDCN achieves more outstanding cluster performance than those existing models. Moreover, the traffic safety state cluster results are statistically analysed and the crash risk level is quantified for each safety state. The risk‐quantized results are consistent with the real road crash situation and this confirms the safety state clustering effectiveness of TSDCN.
Survey of ortho-H2D+ in high-mass star-forming regions
Authors: Sabatini G. , Bovino S. , Giannetti A. , Wyrowski F. , Órdenes M. A. , Pascale R. , Pillai T. , Wienen M. , Csengeri T. , Menten K. M.
Published: November 2020

Context. Deuteration has been suggested to be a reliable chemical clock of star-forming regions due to its strong dependence on density and temperature changes during cloud contraction. In particular, the H3+ isotopologues (e.g. ortho-H2D+) seem to act as good proxies of the evolutionary stages of the star formation process. While this has been widely explored in low-mass star-forming regions, in the high-mass counterparts only a few studies have been pursued, and the reliability of deuteration as a chemical clock remains inconclusive.

Aims. We present a large sample of o-H2D+ observations in high-mass star-forming regions and discuss possible empirical correlations with relevant physical quantities to assess its role as a chronometer of star-forming regions through different evolutionary stages.

Methods. APEX observations of the ground-state transition of o-H2D+ were analysed in a large sample of high-mass clumps selected from the ATLASGAL survey at different evolutionary stages. Column densities and beam-averaged abundances of o-H2D+ with respect to H2, X(o-H2D+), were obtained by modelling the spectra under the assumption of local thermodynamic equilibrium.

Results. We detect 16 sources in o-H2D+ and find clear correlations between X(o-H2D+) and the clump bolometric luminosity and the dust temperature, while only a mild correlation is found with the CO-depletion factor. In addition, we see a clear correlation with the luminosity-to-mass ratio, which is known to trace the evolution of the star formation process. This would indicate that the deuterated forms of H3+ are more abundant in the very early stages of the star formation process and that deuteration is influenced by the time evolution of the clumps. In this respect, our findings would suggest that the X(o-H2D+) abundance is mainly affected by the thermal changes rather than density changes in the gas. We have employed these findings together with observations of H13CO+, DCO+, and C17O to provide an estimate of the cosmic-ray ionisation rate in a sub-sample of eight clumps based on recent analytical work.

Conclusions. Our study presents the largest sample of o-H2D+ in star-forming regions to date. The results confirm that the deuteration process is strongly affected by temperature and suggests that o-H2D+ can be considered a reliable chemical clock during the star formation processes, as proved by its strong temporal dependence.
Biological method in monitoring small rivers of the Oka River basin
Authors: Guseva Tatyana , Mazhayskiy Iyri
Published: November 2020

The Oka basin is characterized by serious environmental problems associated with the depletion of water resources. Communities of aquatic organisms are the first to respond to negative changes in the aquatic environment, such communities are used as indicators in biological monitoring. The aim of the work was to assess the ecological state of the small river of the Oka basin by bioindication. The quality of the water in the reservoir was assessed by chemical indicators - biogenic and technogenic elements. The saprobity index of the reservoir was determined by the species diversity of periphyton. The results revealed technogenic and organic pollution of the small river. According to the results of biological monitoring, the value of the saprobity index is 2.85, which corresponds to class 4 of the reservoir quality, and the water is assessed as polluted. Monitoring the degree of pollution of the small river by the biodiversity of the periphyton community allows you to determine the degree of water pollution quickly.
Structural geological mapping of the Cenozoic sediments of the Brest region using GIS technologies
Authors: Maevskaya Anna , Sheshko Nikolay , Shpendik Natalia , Bogdasarov Maksim
Published: November 2020

Cenozoic sediments of the territory of the Brest region is the object of research in this work. The aim of this work is to detail the structure of the Cenozoic stratigraphic deposits by creating a set of structural geological maps. The process of creating maps included several sequential stages implemented using the ArcGIS 10.5 software product. In general, a set of maps for each period of the Cenozoic era was made according to the implemented method. As a result of mapping, the features of the geological structure of the Cenozoic sediments were detailed (based on the use of the most complete materials on the drilling exploration of the territory during the construction). The use of geoinformation systems in the process of building will allow for quick updating of cartographic materials in the future.
Flexible prefabricated system moravamont 2000
Authors: Cuckič Živko P.
Published: November 2020

At the end of a decade-long research work at the Moravamont plant in Gnjilane, a new completely prefabricated building system was created from reinforced concrete and prestressed precast elements on the track, which was called Moravamont 2000. Presented in paper final results demonstrates that the construction is well and rationally designed, that the construction behaviour for the maximum expected earthquake effects with a return period of 500 years, according to the criterion of regulation, is resistant and resistant to an earthquake without major damage. The idea is to present through new system moravamont 2000 its flexible side along with the possible development using 3D technology.
The Influence of Temperature Impact on the Strength of Adhesion of Polyurethane Glue-foam with Masonry Products
Authors: Derkach Valery
Published: November 2020

The use of masonry on glued polyurethane foam joints can significantly increase labor productivity in the construction of stone buildings. One of the factors restraining the introduction of polyurethane foam adhesive into the practice of construction of stone buildings is insufficient knowledge of the influence of temperature effects on the adhesion of adhesive-foam to masonry products. In order to obtain data on the adhesion strength of polyurethane joints with masonry products under temperature influences, 28 prototypes of masonry were tested, aged in laboratory conditions and also subjected to heating to 100ºC and 200ºC. Tests of masonry samples were carried out in accordance with STB EN 1052-5. Based on the experimental studies carried out and new data on the influence of temperature effects on the adhesion strength of polyurethane joints with masonry products were obtained.
Methodology of application of programmed training in the system of professional training of drivers
Authors: Ageev Evgeny , Vinogradov Evgeny , Novikov Alexandr , Novikov Alexandr
Published: November 2020

This article discusses an improved system for training candidates for drivers of vehicles, identifies factors that affect road safety in the conditions of the road network. The author’s version of the development of a program of programmed training in the system of training candidates for drivers, which is focused on the ability to manage the process of mastering theoretical and practical material. The presented method makes it possible to increase the reliability of vehicle drivers, taking into account individual personal qualities, when performing exercises of road training, the experience of using programmed training in preparation for driving in real time is reflected.
The Quality Improvement of City Passenger Traffic on The Basis of the Passenger Capacity Control
Authors: Trubin Nicolay , Bondarenko Elena , Lyubimov Igor , Sultanov Nail
Published: November 2020

The article presents the reasoning of the development methodology of the quality improvement of city passenger automobile traffic on regular routes based on the modern means use at the accounting of the bus passengers occupancy and intermedia, processing and the information use about the bus fullness by passengers for dispatching management of vehicles operating mode on route.
Analysis and prospects of container and rail transport
Authors: Vakulenko Sergey , Kurenkov Pyotr , Romensky Dmitry , Kalinin Kirill , Gašparík Jozef
Published: November 2020

The article studies the main trends in the market of container transportation in rolling stock of various types, considers the process of transporting large-capacity containers in open wagons. The operational and economic aspects of removing administrative restrictions on the implementation of this type of transportation are noted. The dynamics of rental rates for rental of gondola cars and platforms in 2019-2020 is present. The summary characteristics of the gondola car fleet and fitting platforms on the Russian Railways network have been study. The analysis of the market share of the largest owners of gondola cars and fitting platforms was carry out. The advantages and disadvantages of using the technology of container transportation in open wagons are list. Solutions are propose to create a competitive environment in the container transportation segment of the transport services market.
Experimental research of motor vehicles on a test bench
Authors: Evseev Kirill , Dyakov Alexey , Pashkovskiy Roman
Published: November 2020

The article presents one of the possible methods for testing wheeled, tracked movers and support skis. The drag coefficient values of lateral tire deflection are obtained using a test bench and measuring equipment. Atmospheric and road conditions are taken into account. The tests can be carried out at various loads and velocities.
X-ray spectral analysis of sintered articles made of electroerosive lead bronze obtained in lighting kerosene
Authors: Ageev E.V. , Pereverzev A.S. , sabel’nikov B.N.
Published: November 2020

The article presents the results of X-ray spectral analysis of sintered products made of electroerosive materials of the BrS30 alloy obtained in lighting kerosene. It is shown that during uniaxial pressing and sintering in an argon atmosphere of electroerosive materials of the BrS30 alloy, the main elements on the surface of sintered products are carbon, copper, and lead.
Porous magnesium scaffolds with biodegradable polycaprolactone coating
Authors: Podgorbunsky Anatoly , Mashtalyar Dmitry , Imshineskiy Igor , Sinebryukhov Sergey , Gnedenkov Sergey
Published: November 2020

The results of the synthesis of magnesium matrices with a porous structure have been presented. The cavities sizes vary from 10 microns to hundreds of microns. It has been obtained porous magnesium samples coated by spin-coating with biodegradable polycaprolactone. It has been shown that a dense layer of biodegradable polymer more than 50 μm thickness can be formed on the sample surface. Study of the electrochemical properties of the obtained coatings has been carried out. Obtained results suggest that porous magnesium metals with protective coatings can be used as degradable bone substitute implants.
Study of the composition of innovative materials for the restoration and strengthening of machine parts
Authors: Gorin Andrei , Kuznetsov Ivan , Prokoshina Tatiana , Byrlakova Elena , Kolpakova Svetlana
Published: November 2020

The article describes promising, innovative materials for the restoration of machine parts. The elemental composition was studied by atomic emission spectrometry with inductively coupled plasma. The elemental composition of amorphous alloys of grades 84KHSR, 2HSR, 82H7HSR and nanocrystalline alloy of grade 5BDSR was studied. Based on the results of elemental analysis, it can be argued that the chemical composition of the materials studied by us will help to increase the productivity of technological processes of recovery and the formation of amorphous or nanocrystalline structures of high microhardness in the reducing coatings
Study of the influence of synthesis technologies on the properties of syntactic carbon foams
Authors: Galimov Engel , Galimova Nazirya , Sharafutdinova Elmira , Samoylov Vladimir , Danilov Egor
Published: November 2020

The paper studied the influence of starting components and operating conditions of synthesis processes on the performance properties of syntactic carbon foams. The studies determined the behavior and ranges of hardness, ultimate compressive strength, apparent density, and thermal conductivity of foams made by template carbonization and using carbon microballoons, depending on heat treatment temperature. They determined the influence of a volatile blowing agent (sodium chloride) with wide and narrow fraction on a change in the studied properties of syntactic carbon foams.
Selection of the quantity of the allowance at rough treatment of large – size parts from titanium alloy of BT6 (Russian State Standard GOST 19807-91)
Authors: Lomaeva T. V. , Kugultinov S. D. , Livshits I. I.
Published: November 2020

The article presents the results of experimental studies of the effect of cutting depth on cutting force and the procedure of assignment of allowance value at rough turning and melting of stamped blanks for large- size parts of rocket equipment from titanium alloy VT6. As a result of the studies carried out, empirical dependence of cutting force on cutting depth was obtained, and method of allocation of allowance value was created, which is very important in processing of large-size stamped blanks.
Determination of the parameters of typical multi-link dimensional chains (closing link is tension) using recurrent dependencies
Authors: Shilyaev Sergey , Slashchev Evgeniy , Osetrov Vladimir , Voyachek Igor , Shaikhov Rinat
Published: November 2020

The existing approach to the use of the group interchangeability method during assembly, which are concentrated, has a number of significant drawbacks: 1) there are no formulas for calculating the upper and lower deviations of the component parts of the dimensional chain; 2) deviations are selected without taking into account the design of the component links (the method of equal tolerances is used); 3) the method is applicable for the number of links no more than three with a small number of groups. For other types of problems there is no algorithm, mathematical apparatus, and examples of calculation are not considered sequentially; 4) the calculation by the group interchangeability method is limited by the condition of equal tolerances, i.e. excluding compensators and compensating properties of materials as a part of mechanisms; 5) the calculations are based on assumptions about the economic feasibility of increasing the closing link by a factor of n without taking into account the feasibility of such an increase in the component links that is not permissible in complex mechanisms; 6) the size of the batch of parts and the volume of work in progress are not reflected, as one of the factors of economic feasibility of establishing production tolerance. In this regard, it is necessary to improve the method of achieving accuracy by group interchangeability. This article discusses typical problems that rise when solving dimensional chains in which the closing link is a tension.
Rational reduction of work in progress when assembling parts of a product using the group interchangeability method
Authors: Shilyaev Sergey , Slashchev Evgeniy , Voyachek Igor , Shaikhov Rinat
Published: November 2020

The article discusses the method for interchangeability method. To reduce the volume of work in progress, the design of a fixed combined compensator is developed, which provides stepwise regulation. The article reducing the work in progress by stepwise regulation in multilink dimension chains when assembled using the group proposes a rational technology for the use of combined compensator, taking into account the peculiarities of the group interchangeability method. In order to reduce the work in progress during assembly using the group interchangeability method, two ways of using the combined compensator have been developed: 1 - the inclusion of a compensator in each dimensional chain collected by the group interchangeability method; 2-application of the compensator only at the stage of formation of work in progress during group assembly by replacing one of the parts with it. The peculiarity of the methods is the use of the informational advantage of group assembly — information about the actual dimensions necessary for sorting parts into groups. This eliminates the step of measuring the closing link during assembly and simplifies the design of the compensator, reducing the number of control steps.
Modeling the hardness of the titanium alloy subjected to laser processing
Authors: Gusev Vladimir , Morozov Valentin , Gavrilov Dmitry
Published: November 2020

The article considers the influence of the radiation power W, the longitudinal feed Spr of the laser beam and the distance L from the protective glass of the laser focusing head to the workpiece on the hardness Hv of the titanium alloy TiTaN. A multi-factor model is established that relates the surface layer hardness to the input factors of laser processing and allows you to quickly assign a laser treatment mode and to control it in order to improve the quality of the processed layer. The power W has the greatest effect on the hardness of the surface layer. With increasing W, the hardness increases. Increasing the feed Spr leads to a decrease in the Hv parameter. The effect of the distance L is similar to the radiation power, but the degree of influence of L is more than half as small as W. The developed method of operational assignment of the laser processing mode allows to reduce the auxiliary time for performing the technological operation. The research results are relevant for manufacturing enterprises that implement laser processing processes, as well as for design organizations that develop modern laser equipment.
The creation of objects of the Kazakh culture with the use of additive technologies
Authors: Mukhamadeyeva Railya , Akinov Yerzhan
Published: November 2020

The article presents material about the main prospects for the introduction and operation of new additive technology in the Republic of Kazakhstan. Additive technology (3D printing) is a global phenomenon that contributes to the development of new industries that use digital technologies. 3D printing is necessary for the production of quality products. Kazakhstan, the world’s fifteenth largest gold producer, does not actively promote the jewellery industry. Jewellery is an obligatory attribute of a family celebration and an element of the national culture of Kazakhstan. Jewellery products purchased in Kazakhstan are only 10% local; all the rest are from Russia, Turkey and Europe. New production of jewellery products using three-dimensional modelling and additive technologies should become an image industry in Kazakhstan, due to exclusivity and affordable cost
Finite difference approximation of eigenvibrations of a bar with oscillator
Authors: Korosteleva D. M. , Koronova L. N. , Levinskaya K. O. , Solov’ev S. I.
Published: November 2020

The second-order ordinary differential spectral problem governing eigenvibrations of a bar with attached harmonic oscillator is investigated. We study existence and properties of eigensolutions of formulated bar-oscillator spectral problem. The original second-order ordinary differential spectral problem is approximated by the finite difference mesh scheme. Theoretical error estimates for approximate eigenvalues and eigenfunctions of this mesh scheme are established. Obtained theoretical results are illustrated by computations for a model problem with constant coefficients. Theoretical and experimental results of this paper can be developed and generalized for the problems on eigenvibrations of complex mechanical constructions with systems of harmonic oscillators.
Sensor stability assurance problems and their relationship with the overall problems of providing system performance quality
Authors: Mikhailov Petr , Ualiyev Zhomart
Published: November 2020

Research has been carried out in the field of ensuring the stability of transmitters, which are designed to work in extreme conditions. The complexity of the solved problems and the need for a systemic approach, including structural, material science, are noted. Approaches of leading foreign and domestic companies - manufacturers of sensors and measuring systems to issues of metrological reliability of measuring transducers have been analyzed. Ambiguity of interpretation of the term “stability” by various developers and manufacturers of sensors is shown. Most often, the accompanying documentation for sensors, as well as prospectuses and catalogs indicate a qualitative characteristic, and very rarely quantitative parameters. At the same time, international quality standards indicate the need to disclose qualitative indicators and translate them into quantitative data. The concept of ensuring stability of sensors during their life cycle, based on international quality standards and new design and technological solutions, is proposed. On the example of the beam sensitive element of the metal film pressure sensor, a specific effective technique for stabilizing the electrophysical characteristics of the film heterostructure is shown.
International standards application in machine building
Authors: Ostapenko Maria , Nazarova Vladlena , Voronova Natalia
Published: November 2020

Machine building is one of the leading industries. A modern man cannot exist without mechanical production. Nevertheless, the volume of manufactured products is large, and each part of it requires normative and technical documentation. Standards are introduced at enterprises to meet the demand of consumers in mechanical production. The standards also allow mechanical production to compete in domestic and foreign marketplaces. This paper analyzes the machine-building industry. The features and leading centres of machine-building placement are given. The main standardization problem in the field of machine-building was also considered, and the issue of harmonization of national and international standards for mechanical production was touched. The application of standards at machine-building enterprises was analyzed.
Modelling of layer-by-layer metal removal in the digital twin of the round grinding process performed on CNC machines
Authors: Akintseva Aleksandra , Pereverzev Pavel , Prokhorov Alexander , Kononov Sergey
Published: November 2020

Parts’ processing on circular grinding machines is carried out according to the specified stepwise control cycles of radial and axial feeds, which are laid down in the control program (CP). Despite the precise positioning systems, modern CNC circular grinding machines have a variable compliance of the technological system along the processing length. It causes different cutting depth and occurrence of various errors in dimensions of the diametric surface. Also, the dimensions error increases due to the fact that the processing of parts batch is carried out in unstable conditions and under the influence of different variable factors, which can include allowance fluctuation, blunting of the wheel grains, changes of the wheel diameter and the contact area of the wheel with the workpiece, etc. However, there are still no means of control developed CP, which include cycles of cutting modes, to ensure the accuracy of parts batch` processing. This article describes the digital twin (DT) of the circular plunge grinding with CNC, which allows simulating layer-by-layer metal removal during the whole grinding cycle by calculating the cutting depth on each workpiece revolution under various combinations of unstable processing conditions and variable compliance of TS. Modeling of layer-by-layer allowance removal is performed in several sections of the treated surface; these sections have different compliance. At the end of the grinding cycle in the DT the processing accuracy is estimated on the basis of the obtained values of radii dimensions in all sections of the processed surface. The introduction of DT allows speeding up the CP development, reduce the time of launching CP in production, and increase the productivity of circular grinding operations with CNC by optimizing the cycles of the cutting modes while ensuring the specified processing accuracy.
Spatial reorientation of the carriage of a CNC lathe when reversing
Authors: Denisenko Alexander
Published: November 2020

The process of machining on CNC machines of parts of a complex profile with multi-pass shaping schemes is accompanied by multiple changes in the direction of movement of the working bodies (reverse) during cutting and at idle. In this case, the formation of processing errors associated with the spatial reorientation of the carriage during reversal is possible, the cause of which is the mismatch of the vector of the traction force acting along the axis of the lead screw and the resulting resistance forces associated with cutting forces and friction in the guides. Based on the analysis of the forces acting on the carriage, a design and mathematical model is proposed for guides with prismatic and flat guides. Approbation of the proposed calculation method showed a good level of agreement between the calculated and experimental results. The regularities of the influence of the cutting forces, the location of the center of gravity of the support group, its mass and speed after the reverse on the value of the spatial reorientation have been established.
Determination of burr thickness in high-speed cutting of pipe bundles with circular saws
Authors: Makarova Olga A. , Zhdanov Alexey A. , Kozhevnikova Alla A. , Arzhukhanov Ruslan I. , Van Giang Vu
Published: November 2020

The method of high-speed cutting of cold rolled steel with circular saws is one of the most common in modern mechanical engineering. But often, cutting cold rolled metal is accompanied by the formation of a burr at the ends of the blanks. This machining method is characterized by high productivity, significant tool wear and intense heating of the workpiece due to high cutting speeds. The thickness of this burr is directly dependent on the pipe material, the temperature in the cutting zone and the saw feed. The article proposes a mathematical relation to determine the thickness of the burr by these parameters.
Non-linear discrete model of BLDC motor for studying the range of permissible values of the voltage vector in the state space
Authors: Trefilov Sergei
Published: November 2020

A nonlinear discrete model of a brushless direct current (BLDC) motor in a rotating coordinate system with vector control was developed. The synthesis of optimal control in the state space was performed using the Riccati equation. For practical problems of BLDC motor control, the maximum values of voltages and currents are found while maintaining the identifiability of the BLDC motor model. The study of the range of admissible values of the voltage vector in the state space for the obtained nonlinear discrete model of the BLDC motor is carried out.
Determination of aircraft hydraulic system pipeline leak cause
Authors: Osipok Tatyana , Zaides Semyon , Nguyen Hin
Published: November 2020

The purpose of this article is to determine the cause of leak of the aircraft hydraulic system pipeline detected during pre-flight flight preparation. Results of spectral analysis of material, mechanical testing, analysis of defect structure by optical fractography and metallographic analysis are presented.
Research of algorithms for recognizing and determining the coordinates of apple fruits on the crown of a tree
Authors: Smirnov Igor G. , Krasnoborodko Vladimir V. , Syrovatsky Dmitry A. , Spiridonov Artyom Yu.
Published: November 2020

This paper presents the results of a study of the Apple fruit recognition system on the crown of a tree based on the use of an artificial neural network (ANN). The article describes the process of conducting a multi-factor experiment to determine the relationship between the operating conditions of ANN: illumination, shooting distance, photo resolution, and determining their optimal parameters that allow obtaining the highest quality results. The obtained mathematical model reflects the relationship of such factors as illumination, distance to the object, shooting resolution and their influence on the reliability (accuracy) of object recognition in the photo. The optimal parameters of these factors are determined, at which the maximum value of recognition reliability of the desired objects is reached.
Accurate ground scanning of the day surface of tilled soil to determine its agro-technical characteristics
Authors: Vasiliev Sergey , Alekseev Viktor , Vasiliev Mikhail
Published: November 2020

The aim of the research is to determine the agro-technical characteristics of the day surface of tilled soil on sloping agricultural landscapes by applying the method of accurate ground scanning along the circumference. The specific difficulties that arise in developing and implementation of agro-technical measures are often associated with significant change of the main parameters of the day surface of tilled soil depending on space and time. Agro-technical parameters according to the agro-technical requirements for the main and pre-sowing tillage, the direction and value of the average slope of the soil surface, as well as the lumpiness and cloddiness of the tilled day soil surface are determined while controlling. According to the results obtained using the developed software, it was found that the deviation angle of the projection of the line of the maximum change in height from the direction of the tillage machine movement is α=-32.4 and the slope of the studied site is 4.8 degrees. The aggregates of 1-4 centimeters in diameter are prevailing in quantity that is crumbling is ensured. The weighted average diameter of the lumps was 4.07 cm, and the standard deviation was 5.05 cm.
Development of the module software for control technological processes of the gravitationally-pneumatic grain cleaner
Authors: Gerasimenko Stanislav , Adamyan Artak , Moskovsky Maksim , Quang Minh Bui
Published: November 2020

Increasing in the volumes of processed cereals crops and leguminous crops products is the main reason for the decrease in the productivity of the separation process of the impurities and the quality of the final product. In this regard, the automation of technological processes is a topical aim. This article presented the process of creating a software module to control and manage the main parameters of agricultural processes. On the basis of this developed software, an experimental model was designed and tests were conducted.
Association of Macrophage Migration Inhibitory Factor Gene –173 G/C Polymorphism (rs755622) with Familial Mediterranean Fever in Children
Authors: Cakan Nursen , Yılmaz Resul , Karaaslan Erhan , Ateş Ömer
Published: November 2020

Objectives The aim of this study was to identify the genotypic analysis and allele frequencies of the –173 G/C polymorphism in the macrophage migration inhibitory factor (MIF) gene in children diagnosed with familial Mediterranean fever (FMF).

Methods The study included 98 children who were diagnosed with FMF according to the Tel Hashomer criteria and one hundred and 57 healthy children as the control group. Genotyping was done for a polymorphism in a promoter region of the MIF gene (G/C at position –173).

Results The relationship of FMF prevalence and –173 G/C genotype of the MIF gene was statistically significant. Individuals with the CC genotype seem to be predisposed to FMF.

Conclusion The C/C polymorphism at position –173 of the MIF gene could be associated with excessive inflammation and immune response and can lead to susceptibility to FMF