Functionally-oriented technology for backing-off of new standard gear-cutting hobs

The results of scientific research of production technology aimed at identifying predictable errors and ensuring the required quality of processing are presented.

SIMULATION OF THE CONTROL PROCESS ELECTRIC LOADS IN THE DISTRIBUTION NETWORK OF 0.4 KV

В статье рассматривается решение задачи моделирования процесса управления электрическими нагрузками для повышения качественных показателей электрической энергии в распределительных электрических сетях 0,4 кВ на основе использования адаптивной системы управления электрическими нагрузками. Проведен анализ существующих методов снижения неравномерности распределения мощностей. Алгоритм процесса управления электрическими нагрузками в распределительных электрических сетях, алгоритмы анализа распределения мощностей и напряжений по фазам сети, а также алгоритм устранения отклонений напряжения, которые могут быть использованы при разработке электрооборудования. для обеспечения необходимого качества электроэнергии. The paper considers the solution of the problem of modeling the process of controlling electrical loads to improve the quality parameters of electrical energy in distribution electrical networks of 0.4 kV based on the use of an adaptive system for controlling electrical loads. The analysis of existing methods of reducing the uneven distribution of capacities is carried out. An algorithm for the process of controlling electrical loads in distribution electrical networks, algorithms for analyzing the distribution of powers and voltages over the phases of the network, as well as an algorithm for eliminating voltage deviations, which can be used in the development of electrical equipment to ensure the required quality of electricity, have been developed.

ASSESSMENT OF THE IMPACT OF TECHNOLOGICAL HEREDITY ON INDICATORS OF RELIABILITY, DURABILITY AND ENVIRONMENTAL SAFETY OF ELEMENTS OF GAS TRANSMISSION SYSTEMS

Modern gas transmission systems are power facilities based on a main pipeline, which is a continuous pipe, along which devices are placed that provide gas pumping at predetermined parameters. Unlike other linear structures, such as roads, railways, the main pipeline throughout the entire period of operation is in a complex stress state under the influence of the internal pressure of the pumped product and functions as a pressure vessel. The operational reliability, durability and environmental safety of gas transmission systems are ensured by various control devices and pipe fittings. The article discusses issues related to predicting the operation of pipe fittings during the operation of the gas transmission system, while ensuring the required reliability, durability and environmental safety. An analysis of the phenomena of technical heredity is given, with the help of which it is possible to determine the causes of deviations in the output parameters of pipe fittings in the process of their manufacture or repair. It has been proved that the main feature of technological heredity is the transfer of a certain technological property from the previous technological operation to subsequent ones, characterized by the transfer coefficient of technological heredity. An indispensable condition for the monotonicity of changes in the transmission coefficient of technological heredity in order to ensure the required quality of manufacture or repair of pipe fittings is revealed. The economic principle of predicting the quality of manufacturing or repair of products is proposed for use, a relationship is found between the initial and output technological properties of pipe fittings, a route is chosen to achieve the required quality of its manufacture or repair, including procurement and finishing technological operations.

Substantiation of the Energy Efficient Schedules of Drying Grain Seeds

It is important to study the patterns of drying grain seeds in order to improve the energy efficiency of the process. Energy efficiency is one of the main parameters that define the choice of a drying schedule. Traditional drying technologies are based on low temperature schedules, which do not allow significantly intensifying the process by increasing the temperature of the heat agent because of substantial reductions in the quality of the material. To adequately assess the drying schedules, we conducted the study of drying grain seeds at low temperatures aimed to preserve the seed properties of the material. To increase the energy efficiency of the drying process, a step-by-step descending low-temperature drying schedule was suggested, which provides for the required quality of seed material. All the proposed technical solutions for the energy-efficient schedules of drying grain seeds were summarized in the recommendations for industrial drying in column type direct-flow grain dryers.

Adaptive replication strategy based on popular content in cloud computing

The cloud is an infrastructure that provides decentralized on-demand services. It allows consumers to pay only for the services they use. The consumer is the important entity in the cloud. The violation of the SLA contract between the consumer and the provider often leads to consequences because the service provider has to pay penalties. Data replication is emerging as an ideal solution to meet the new challenges of the cloud. This paper proposes a new replication strategy based on the popularity of data. This strategy adaptively selects the files to be replicated to improve the overall availability of data in the system, minimize query response time, and achieve the required quality of service. In addition, it dynamically determines the number of replicas to add and the best locations to store them. Experimental results show the effectiveness of the proposed strategy.

TERMINATION OF PREGNANCY: TRENDS OF THE LAST DECADE

В нашу работу вошли 2 исследования (380 пациенток), которые получали препараты прогестерона перорально или вагинально. Представлена современная классификация. Освещены вопросы этиологии и патогенеза данного осложнения, критерии диагностики, а также стандарты терапии и возможности профилактики. Также проведен обзор пяти больших исследований, включивших 980 пациенток. Авторы провели скрининг тысяч публикаций по нескольким критериям и только пять публикаций соответствовали необходимым критериям качества. Our work included 2 studies (380 patients) who received progesterone preparations orally or vaginally. The modern classification is presented. The issues of the etiology and pathogenesis of this complication, the diagnostic criteria, as well as the standards of therapy and the possibilities of prevention are highlighted. We also reviewed five large studies involving 980 patients. The authors screened thousands of publications against several criteria, and only five publications met the required quality criteria.

Improving the efficiency of machining on metal-cutting machines by aligning the CNC program and the evolutionarily changing cutting dynamics

Modern machines with high accuracy provide an accordance of the trajectories of the executive elements to the CNC program. However, this is not guarantee the same accuracy of manufacturing the part. One of the main reasons for the formation of the geometric defects is the elastic deformations of the tool and the workpiece. It is caused by variations of the cutting forces, changes in the rigidity of the workpiece along the tool path. It depends on changes of the properties of the dynamic link formed by cutting. Therefore, there is a problem of synergetic aligning of controlled trajectories with changing cutting properties. In the article, the regularities of the alignment of external control and internal dynamics are considered on the basis of mathematical modeling of the system in which the trajectories of the executive elements are controlled. The case of accounting the a priori given law of changes of the stiffness of the workpiece is considered. The effectiveness of the alignment is estimated by the reduced costs while ensuring the required quality of the parts.

Operations for the preparation of metal powders for hot isostatic pressing

Powder metallurgy as a method of manufacturing and processing metals is very diverse in its technological methods. This makes it possible to obtain parts of the required quality and necessary properties. Using the methods of powder metallurgy production, specialists can produce the latest composite materials, the production of which is impossible by traditional methods. The production of machine parts and mechanisms from metal powders provides significant savings on material, due to the low consumption coefficient. Metal powders are usually manufactured in specialized factories, but sometimes they are produced directly by the consumer; in this case, the manufacturing process is built in direct accordance with the requirements of this consumer. If the powder comes from a third-party supplier, there is a need for special preparation operations, before starting production, to give the powder certain chemical and physical characteristics. Hot isostatic pressing technology is a complex technological process in which a large number of parameters affect the quality of the final product. The complexity of the GIP process lies in various thermal, physical, and mechanical interactions. In this regard, a large role is played by the processes for preparing the powder for the GIP. The article describes the main operations for the preparation of powder for hot isostatic pressing.

Analysis of Fabricability of Flexible Waveguide Parts for Satellite Applications

Satellite onboard equipment includes waveguide transmission lines. One of the tasks to be solved is the temperature decoupling of the waveguide path and onboard equipment devices. In order to prevent waveguide path deformation during expansion/contraction due to thermal effects, the waveguide is equipped with a flexible waveguide section capable of changing the length without deteriorating radio technical characteristics. The paper considers the issues of fabrication of flexible waveguide parts, concerning the requirements for structure, properties, heat treatment of raw materials, dimensions of workpieces, equipment, and tooling. Within the study, we optimized and tested in practice operations of the technological process of extracting parts from sheet material, rolling, profiling, and shaping, which make it possible to manufacture parts of waveguide paths of the required quality.