The methods of the intensification of the GTE discs and shafts hard materials turning

Сформульовано проблему підвищення ефективності виготовлення дисків і валів ГТД за рахунок інтенсифікації точіння. Розглянуто перспективи використання матеріалів у літакобудуванні. Надано оцінку об’єму використання токарних операцій у механообробні дисків і валів ГТД. Запропоновано феноменологічну модель інтенсифікації процесу точіння важкооброблюваних матеріалів. Стисло розглянуто основні методи вдосконалення процесу точіння. Зроблено огляд прогресивних комбінованих методів обробки різанням важкооброблюваних матеріалів. Зроблено висновок про актуальність дослідження методу безпосереднього управління контактними і тепловими явищами для інтенсифікації токарної обробки ТОМ.Purpose. Search for promising ways to intensify of the GTE discs and shafts hard materials turning. Analysis of the scientific advances in this field. Specification purpose of scientific research aimed at the intensification of turning. Design/methodology/approach. The problem of increasing the efficiency of the GTE disks and shafts production through the intensification of the turning is still relevant because of the tendency of materials used in aircraft engine. With regard to the manufacturing processes of the gas turbine engines discs and shafts, the proportion of turning operations in the structure of some of them reaches 60%. The authors offer the phenomenological model of the intensification of difficult to cut materials turning and describe in short the basic methods of the cutting process improving. A review of the progressive combined machining methods of difficult to machine materials detects the presence of significant shortcomings. For a more elegant technical solution proposed the method of the direct control of contact and thermal phenomena for intensification of the difficult to cut materials turning. Findings. In order to intensify the turning of the GTE discs and shafts necessary to investigate the possibility of implementing the method of direct control of contact and thermal phenomena during processing. Originality/value. The phenomenological model of the intensification of difficult to cut materials turning is offered. The purpose of scientific research aimed at the intensification of turning is specified.Сформулирована проблема повышения эффективности производства дисков и валов ГТД за счет интенсификации точения. Рассмотрены перспективы использования материалов в авиастроении. Дана оценка объема применения токарных операций в механообработке дисков и валов ГТД. Предложена феноменологическая модель интенсификации процесса точения труднообрабатываемых материалов. Кратко рассмотрены основные методы совершенствования процесса резания. Выполнен обзор прогрессивных комбинированных методов обработки резанием труднообрабатываемых материалов. Сделан вывод об актуальности исследования метода непосредственного управления контактными и тепловыми явлениями для интенсификации токарной обработки труднообрабатываемых материалов

Molecular structure and properties of κ-carrageenan-gelatin gels

© 2018 Elsevier Ltd Rheological studies, FTIR spectroscopy and a molecular docking approach were used to explore the structural basis of the peculiar physicochemical properties of gelatin gels modified with a κ-carrageenan admixture. Mixed gel properties are affected by the polysaccharide-to-gelatin ratio, Z, and can be divided into two categories. At low ratios, the strength of mixed gels varies insignificantly compared to gelatin due to the similar structures of the gels. Above the threshold content of κ-carrageenan (Z > 0.1), the storage modulus and yield stress of mixed gels are significantly enhanced. The nonadditivity and threshold character of the rheological properties could be the result of conformational ordering of both gelatin and κ-carrageenan, leading to the formation of additional junction zones in the gel network. According to molecular docking studies, the junctions could be formed as a result of complementary interactions between the gelatin triple helix and the κ-carrageenan double helix. The stack formation increases the interaction energy, which explains the strengthening of the gel network

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Polymorphic minisatellite ecNOS4a/4b of the endothelial NO synthase gene and cardiovascular disorders

[No abstract available