INFLUENCE OF TOOLING SYSTEM ACCURACY ON DYNAMIC CHARACTERISTICS OF MULTI-PURPOSE MACHINE

Рассмотрена характерная для современного машиностроения тенденция по увеличению концентрации технологических операций на многоцелевых станках и интенсификации режимов резания. Приведен анализ станочных парков различных металлообрабатывающих предприятий, который показал преобладание станков фрезерно-расточной группы. Проанализированы причины широкой номенклатуры инструментальной системы станков фрезерно-расточной группы и рассмотрено влияние многообразия инструментальной системы на динамические характеристики многоцелевых станков. Рассмотрен пример характерной для станков фрезерно-расточной группы среднего типоразмера инструментальной системы, которая включает в себя цанговый патрон, цангу и фрезу. Приведены расчеты точности и жесткости для различных вариантов инструментальной системы. С целью подтверждения полученных теоретических расчетов были проведены экспериментальные исследования в условиях реального производства при обработке серийно изготавливаемой детали типа «Корпус» на фрезерном многоцелевом станке модели VMC-600. Результаты обработки экспериментальных данных показали, что точность инструментальной системы значительно влияет на геометрическую точность обработанной детали, виброустойчивость инструментальной системы и ее жесткость. Низкая точность инструментальной системы приводит к значительному отжиму режущего инструмента на рекомендуемых режимах резания, который может превысить величину допуска на обработку, что должно быть учтено на этапе проектирования технологического процесса путем занижения режимов резания The article discusses the characteristic tendency of modern mechanical engineering to increase the concentration of technological operations on multi-purpose machine tools and intensify cutting modes. We give the analysis of machine parks of various metalworking enterprises, which showed the prevalence of milling and boring machines. This article analyzes the reasons for a wide range of tool systems for milling-boring machines and considers the influence of the diversity of the tool system on the dynamic characteristics of multi-purpose machines. We considered an example of a medium-sized tool system typical for milling and boring machines, which includes a collet chuck, a collet and a milling cutter. We give calculations of accuracy and stiffness for various versions of the instrumental system. In order to confirm the obtained theoretical calculations, we carried out experimental studies in real production conditions when processing a serially manufactured part on a VMC-600 multi-purpose milling machine. The results of experimental data processing showed that the accuracy of the tool system significantly affects the geometric accuracy of the machined part, vibration resistance of the tool system and its rigidity. The low accuracy of the tool system leads to a significant squeezing out of the cutting tool at the recommended cutting conditions, which can exceed the machining tolerance, which should be taken into account at the design stage of the technological process by understating the cutting conditions

CLASSIFICATION OF AUTOMATED STABILIZATION INSTRUMENT COMPLEXES

The article is devoted to automated instrument stabilization systems. The authors systematized and presented the classification of modern stabilizers. High-precision automated instrument stabilization systems are used in light armoured vehicles, performing the functions of search acceleration, determining the coordinates of moving objects in extreme conditions; observation of ground, air and surface targets. Also promising is the use of automated instrumentation stabilization systems in aviation gravimetry for the exhibition of the axes of sensitivity of navigation sensing elements (gravimeters). A characteristic feature of the development of modern technology is the improvement of technical characteristics of all instrumentation systems that are part of the product management system, including stabilizers. This process is due to the transition to a digital element base, the use of new information sensors, new optoelectronic surveillance devices and the development of new circuit design solutions, which, in turn, increases the speed of equipment and its manoeuvrability due to greater automation. The article reveals the principle of classification of stabilizers: by object of stabilization, by number of stabilization planes, by type of measured coordinate, by gyroscope function, by type of actuator, by type of regulation, by type of circuit design. The functioning of the digital instrumental system for measuring mechanical parameters and stabilization by means of functional and structural diagrams of the channel of the automated instrumental stabilization complex is shown. The above is a new, more detailed classification of automated instrumentation stabilization systems, which systematizes the principles of construction of modern stabilizers.

The Moderating Role of Natural Resources Between Institutional Quality and CO2 Emissions: Evidence From Developing Countries

The recent study aim is to scrutinize the moderating role of natural resources between institutional quality and carbon dioxide (CO2) emissions in 106 developing countries from 1996 to 2017 by using dynamic fixed effect, generalized method of moments (GMM) and system generalized method of moments (system GMM) estimators as well as apply the instrumental fixed effect, the instrumental time fixed effect and instrumental system GMM estimators as robustness. We make use of dynamic models and instrumental system GMM to reduce the result of autocorrelation increasing from misspecification of a model as well as clear the biases from unnecessary data and solve the possible endogeneity issues. The empirical results indicate that financial development, trade, and institutional factors: corruption perception control, government effectiveness, political stability, regulatory quality, rule of law, and voice and accountability play a vital role in CO2 emissions reduction but natural resources along with economic growth are the core factors that cause CO2 emission in developing countries. On the opposing, natural resources boost the indirect impact of institutional quality on CO2 emissions in developing countries.

Trans‑Image in Viktor Sidorenko’ Creative Work

The aim of the article is to investigate the transformation of the image as a morphological unit of modern visual art on the example of the creative work of a Ukrainian artist and researcher of modern visual art Viktor Sidorenko. The research methodology is based on the methods developed in the works of J. Landsdown and S. Schofield, S. Yerokhin and others. The paper presents an attempt to study a new type of image – post-post-classical image, which has an ontologically transgressive character. The research has important implications for understanding the modern morphological changes in the visual sphere, the instrumental system of these changes that ensures the presence of its two mutually antithetical trends: transgressive and synergetic. The author analyzes the publications in which the link between the morphology of the visual sphere and the latest developments in the creation of visual space are explored. The choice of Victor Sidorenko’s creative work as a research material is not accidental. It is in the work of this artist that the genesis of the modern post-post-classical image and the transformation of its space as polymorphic can be clearly traced. The attraction to photographicity on the one hand, and author coding, on the other, becomes an ontological feature of V. Sidorenko’s authorial construction of pictorial space and in further creative searches. A certain culmination of this stage in the artist’s visual work is the already famous full‑scale visual project “The Mill of Time” (2003). It is in this project that V. Sidorenko creates a trans‑image as a space of a new type, in which photography, installation, painting, living objects and video projection create a post-classical type of image. The paper considers Victor Sidorenko’s creative work as a vivid example of the genesis of the image, whose ontological feature is its transgressive character. This is an image of the post-post-classical type, whose pictorial space can consist of classical, non‑classical and post-classical images. At the present stage, there have been changes in the strategies of representation of the trans‑image as such. The main strategy of its representation is a polymorphic visual project, which synergistically combines different types of images, bringing their semantic content beyond a stable visual form.

Zebrafish Models of Photoreceptor Dysfunction and Degeneration

Zebrafish are an instrumental system for the generation of photoreceptor degeneration models, which can be utilized to determine underlying causes of photoreceptor dysfunction and death, and for the analysis of potential therapeutic compounds, as well as the characterization of regenerative responses. We review the wealth of information from existing zebrafish models of photoreceptor disease, specifically as they relate to currently accepted taxonomic classes of human rod and cone disease. We also highlight that rich, detailed information can be derived from studying photoreceptor development, structure, and function, including behavioural assessments and in vivo imaging of zebrafish. Zebrafish models are available for a diversity of photoreceptor diseases, including cone dystrophies, which are challenging to recapitulate in nocturnal mammalian systems. Newly discovered models of photoreceptor disease and drusenoid deposit formation may not only provide important insights into pathogenesis of disease, but also potential therapeutic approaches. Zebrafish have already shown their use in providing pre-clinical data prior to testing genetic therapies in clinical trials, such as antisense oligonucleotide therapy for Usher syndrome.

Technological modes of metals direct reduction in an aggregate of jet-emulsion type

The paper presents the method and instrumental system for modeling and optimizing technological modes of direct metal reduction processes in a jet-emulsion aggregate (JER). Stages of the method are considered. The first one is the problem statement: formation of target conditions, choice of the process type, the task and system of optimization criteria. The second stage includes selection of the object of study: setting parameters of input and output flows, process parameters, stages and subprocesses. The third one includes thermodynamic modeling to assess the final equilibrium state in which optimization problem is solved to determine the best conditions for implementation of the processes of metal reduction from oxides in model systems. The fourth stage is development of metallurgical technology (finding the optimum modes and ways for achieving these modes by specified output stream parameters). And the final one is process optimization in technical and economic indicators. As part of the fourth stage, the complex of mathematical models has been developed that reflects relationship of flows and processes in a metallurgical unit. The structure of instrumental system is presented, in which mathematical models and an algorithm for determining optimal technological modes are implemented. A set of optimization criteria has been developed and a scheme for solving two types of optimization problems are presented: finding optimal conditions for reduction processes in thermodynamic systems and determining optimal modes of direct metal reduction. Application of the method to develop optimal technological modes of direct metal production in a JER-type aggregate is shown: metal production from cast iron and mill scale; direct reduction of metal from dusty ores and iron-containing man-made materials; obtaining manganese alloys from carbonate and oxide ores; processing titanium-magnetite concentrates with an almost complete separation of iron-containing and titaniumcontaining component; and direct reduction of iron with associated production of high-calorie synthesis gas.

Quantification of one Prenylated Flavanone from Eysenhardtia platycarpa and four derivatives in Ex Vivo Human Skin Permeation Samples Applying a Validated HPLC Method

Prenylated flavanones are polyphenols that have diverse biological properties. The present paper focuses on a HPLC method validation for the quantification of prenylated flavanones (2S)-5,7-dihydroxy-6-(3-methyl-2-buten-1-yl)-2-phenyl-2,3-dihydro-4H-1Benzopyran-4-one 1 and derivatives (2S)-5,7-bis(acetyloxy)-6-(3-methyl-2-buten-1-yl)-2-phenyl-2,3-dihydro-4H-1-Benzopyran-4-one A; (2S)-5-hydroxy-7-methoxy-6-(3-methyl-2-buten-1-yl)-2-phenyl-2,3-dihydro-4H-1-Benzopyran-4-one B; (8S)-5-hydroxy-2,2-dimethyl-8-phenyl-3,4,7,8-tetrahydro-2H,6H-Benzo[1,2-b:5,4-bˈ]dipyran-6-one C; and (8S)-5-hydroxy-2,2-dimethyl-8-phenyl-7,8-dihydro-2H,6H-Benzo[1,2-b:5,4-bˈ]dipyran-6-one D applied in biopharmaceutic studies. The linear relationships are proven with significant correlation coefficients (R2 ˃ 0.999) in the range of 1.56 to 200 μg/mL with low limits of detection and quantification, on average of 0.4 μg/mL and 1.2 μg/mL, respectively. The validation method used in this work is highly accurate and precise, with values lower than 15%. The relative standard deviation values of repeatability of the instrumental system are demonstrated with less than 0.6% for all studied flavanones. Therefore, the applicability method of the quantification of the prenylated flavanones was established using the permeation of human skin in the Franz cell system. During the method previously described, there was no interference observed from human skin components in ex vivo permeation studies.

"Electronic tongue" in the Food Industry

“Electronic tongue” (e-tongue) is instrumental system are designed to crudely mimic human taste sensory organs and are composed of an array of sensors. Complex data sets from „e- tongue“ signals combined with multivariate statistics represent rapid and efficient tools for classification, recognition and identification of samples, also for the prediction of concentrations of different compounds. A wide variety of sensors can be employed into the design of these instrumental systems, especially that of „e-tongues“, offering numerous practical applications. In this study are review, characteristics of sensors and possibilities „e-tongue“ applications in the food industry.Practical applications: The “e-tongue” can be used in various applications, including on quality control in the food industry and pharmacy.