The definition of the range of stable operation of the vortex granulators suspended layer

Author(s):  
Vladimir Vedmedera ◽  
Aleksandr Kremnyov ◽  
Artyom Artyuhov
Author(s):  
Vita Vynogradnya ◽  
Lyudmila Burdonos

 Issues of ensuring the financial stability of enterprises are extremely important for the socio-economic development of Ukraine. Stable operation of the enterprise is possible only if the appropriate level of solvency of the enterprise. That is why the issues and problems related to ensuring solvency are given much attention in the scientific works of scientists from both foreign and domestic scientific schools. At the same time, insufficient attention is paid to long-term solvency as an important component of the system of ensuring the stable functioning and development of the enterprise in the future. The task of the study is to analyze the approaches of scientists to the interpretation of the essence of prospective solvency and its role in ensuring the stable operation of the enterprise, determining the characteristic causes of its decline in modern socio-economic development of Ukraine; development of a proposal to ensure the solvency of the enterprise in the future. In the process of research general and special methods were used: analysis and synthesis, method of comparison, generalization, statistical, etc. The article considers the essence of perspective solvency of the enterprise and its role in ensuring stable functioning of the enterprise. The factors that determine it are systematized. The conceptual model of providing perspective solvency of the enterprise for the purpose of stable functioning and development of the enterprise which provides: definition of system of the corresponding indicators of perspective solvency for their constant monitoring is offered; finding out the possible reasons, which may result in loss of prospective solvency; the sequence of implementation of the necessary measures for its restoration and provision in the future. The results of this study can be used in the process of enterprise management to determine the real state of its solvency and develop measures to ensure it in the medium and long term.


2019 ◽  
Vol 294 ◽  
pp. 03007
Author(s):  
Adam Razgonov ◽  
Anton Zhuravlyov ◽  
Kateryna Yashchuk ◽  
Vadym Shcheka

The problems of electric track circuits calculating were investigated in the works of various authors, it is noted that there is no complete clarity on the definition of shunt resistance. The value of the calculated train shunt resistance in many respects affects the area of signaling systems rail channel stable operation and train traffic safety. It is relevant to study the possibilities of changing the standard value of and the conditions for the execution of track circuits shunt mode, especially for sections of railway with low resistance insulation of the rail line. The surface area of the “wheel-rail” skating, taking into account the different conditions of interaction dynamics and wear of rails and wheel elements were obtained in article. It is shown that the reduction of the normative value of the resistance of the train shunt is appropriate for signaling systems, especially for sections of railway with low resistance insulation of the rail line. An approximate estimate of the geometric parameters of the membrane that forms on the “wheel-rail” surface is obtained; proposed a more complete electrical replacing scheme for the train shunt circuit, which allows analyzing the influence of the circuit elements parameters values and the frequency of the signal current. A method for calculating the correlation dependence of the train shunt resistance from wheel-rail surface membrane parameters is proposed.


2021 ◽  
pp. 32-42
Author(s):  
A. B. Feonichev ◽  
K. Yu. Meleshin

The article discusses the basic concepts of modern security theory: “danger”, “threat”, “challenge”, “risk” and “interest”. Based on the analysis of the content and correlation of these terms, the essence, nature and causes of threats to the national security of the Russian Federation are consider. The authors propose a revised definition of “threat to national security” as “a potential problem situation, which, without timely detection and resolution may lead to violation of stable operation or the destruction of the state”. Analysis of modern scientific literature on national security issues has shown that the term “call”, used in the meaning of “signal messages”, does not coincide with the original meaning of the term, understood as “challenge” — a problem C Based on this, the concepts of “threat” and “challenge” (understood as a problem situation) are synonymous. As a result, the authors concluded that there are two different conceptual approaches to security. Eurasian, which is characterize by the “threat — danger — damage” model, and Anglo-Saxon, which considers the mechanism of threat development through the “interest — control — lack of control — challenge — risk” model. In this case, interest and control are consider in relation to resources, territories, technologies, challenge as a problem situation that needs to be solved and risk as a possibility of lost profits. 


2021 ◽  
Vol 11 (8) ◽  
pp. 3679
Author(s):  
Martina Kajanova ◽  
Peter Bracinik

With an increasing number of electric vehicles (EVs), their owners’ involvement in the control of electric power systems and their market seems to be the only option for stable operation of future power networks. However, these people usually have little knowledge about power systems’ operation and follow just their interests. Therefore, this paper deals with the decision-making process of EV drivers at the charging station. The paper presents the stated preference survey used to collect the responses to hypothetical scenarios, where respondents chose between three alternatives, namely slow charging, fast charging, and vehicle-to-grid services. The survey also contained questions about respondents’ socio-demographic characteristics, as gender, age, etc. The decision-making prediction models for each socio-demographic characteristic were created using the acquired data. The paper presents the estimated parameters of the attributes affecting the respondents’ choices for the models that allow models’ simple implementation. Knowing these models and the customers’ composition, the operators of the charging stations or the distribution networks could better estimate EV owners’ behavior and so their expected power demand. Moreover, operators could more effectively implement incentives for their customers and affect the customers’ behavior in a way that is suitable for better operation of their power systems.


2021 ◽  
Vol 9 ◽  
Author(s):  
Lijuan Li ◽  
Yiwei Zeng ◽  
Jie Chen ◽  
Yue Li ◽  
Hai Liu ◽  
...  

With the increase of complexity of the power system structure and operation mode, the risk of large-scale power outage accidents rises, which urgently need an accuracy algorithm for identifying vulnerabilities and mitigating risks. Aiming at this, the improved DebtRank (DR) algorithm is modified to adapt to the property of the power systems. The overloading state of the transmission lines plays a notable role of stable operation of the power systems. An electrical DR algorithm is proposed to incorporate the overloading state to the identification of vulnerable lines in the power systems in this article. First, a dual model of power system topology is established, the nodes of which represent the lines in the power systems. Then, besides the normal state and failure state having been considered, the definition of the overloading state is also added, and the line load and network topology are considered in the electrical DR algorithm to identify vulnerable lines. Finally, the correctness and reasonability of the vulnerable lines of the power systems identified by the electrical DR algorithm are proved by the comparative analysis of cascade failure simulation, showing its better advantages in vulnerability assessment of power systems.


2020 ◽  
Vol 288 (6) ◽  
pp. 106-111
Author(s):  
О. VIVCHAR ◽  

The purpose of the article is to substantiate the essential characteristics of economic security enterprises, as well as the formation of main criteria for assessing its reliability and efficiency in modern transformational conditions. Methods. To solve this scientific problem used: structural method – to build the structure of the article; comparative analysis empirical data – to pose the problem and study the object of study; abstract-logical generalization – to justify clarifications of scientific concepts of economic-mathematical model. The Results. A comprehensive study of essential and substantive characteristics the economic security of enterprises in modern market conditions. Scientific novelty. The author’s vision the scientific definition of economic security at enterprises is offered, which, in contrast the existing ones, allowed to identify the preventive nature with the selection of criteria for assessing its reliability and efficiency: ensuring stable operation of enterprises, preservation and increase of finances and material values; sustainable development, preservation and increase of material values the enterprise, high level of competitiveness production; use of innovative technologies in production activities; inviolability of commercial information and all resources; timely prevention of crisis situations and neutralization of negative factors affecting the activities of the enterprise. The practical significance. The main provisions of the scientific article will provide an opportunity to apply in practice the indicators of effectiveness the economic security of enterprises.


2021 ◽  
pp. 42-48
Author(s):  
R. V. Gavva ◽  
E. N. Lozhkomoeva

The article considers the essence and role of strategic planning in the activities of organizations of the tourism industry. The paper shows that the concept of the life cycle of tourist services can serve as a justification for strategic management decisions. The authors formulate the main approaches to the study of the life cycle of tourist services. The study determines the directions of using information at different stages of the life cycle of services in the field of tourism. The article proposes approaches to the operational definition of the type of service and the stage of its life cycle, which contributes to the adoption of sound strategic management decisions that ensure the effective, stable operation of tourist organizations. The paper determines that the modern development of the tourism market should be based on a combination of regional, Federal, national, and international tourism policies that combine strategic planning with the tasks and needs of the short-term perspective.


Author(s):  
Thom M. Eldridge ◽  
Thomas A. Soulas

Damper seals (such as honeycomb and hole pattern seals) have been widely used in the turbomachinery industry to counterbalance destabilizing aerodynamic forces acting on the rotor system and to provide the necessary amount of damping for stable operation of the machine. Recent experience and research developments have focused the interest of the turbomachinery community on the dynamic characteristics of the divergent-taper damper seal. In addition to offering a review of the current literature on the subject of interest (in order to provide a comprehensive vision of the overall phenomenon), this paper extends the discussion for a better understanding of the mechanism and impact of damper seal clearance divergence on the rotordynamics of a rotor-bearing-seal system (as applied to centrifugal compressors). The analysis of a damper seal alone is insufficient to assess the influence of this component on the rotordynamic stability of a turbocompressor. This paper will show the variation of a complete rotor-bearing-seal system’s logarithmic decrement as a function of the hole pattern seal clearance divergence for a sample centrifugal compressor application, as analyzed with the proprietary, state-of-the-art rotordynamic software suite from the author’s company. This divergence-based transition of system logarithmic decrement from positive to zero (thereby implying the onset of instability) leads to the definition of a “damper seal divergence stability threshold.” Divergence in a damper seal can originate from numerous sources, including taper produced during manufacture, and pressure or thermal-driven distortion of the seal under operation. While small damper seal divergence may first produce an increase of the system logarithmic decrement, additional seal divergence has a dramatic effect on the first forward whirling mode natural frequency, as well as on the logarithmic decrement of that mode. This paper describes the analytical methods used to derive the stability of the rotor-bearing-seal system. It also presents a practical experience that stresses the necessity for a sound approach to properly evaluate the impact of a divergent damper seal on the stability of centrifugal compressors.


1966 ◽  
Vol 24 ◽  
pp. 3-5
Author(s):  
W. W. Morgan

1. The definition of “normal” stars in spectral classification changes with time; at the time of the publication of theYerkes Spectral Atlasthe term “normal” was applied to stars whose spectra could be fitted smoothly into a two-dimensional array. Thus, at that time, weak-lined spectra (RR Lyrae and HD 140283) would have been considered peculiar. At the present time we would tend to classify such spectra as “normal”—in a more complicated classification scheme which would have a parameter varying with metallic-line intensity within a specific spectral subdivision.


1975 ◽  
Vol 26 ◽  
pp. 21-26

An ideal definition of a reference coordinate system should meet the following general requirements:1. It should be as conceptually simple as possible, so its philosophy is well understood by the users.2. It should imply as few physical assumptions as possible. Wherever they are necessary, such assumptions should be of a very general character and, in particular, they should not be dependent upon astronomical and geophysical detailed theories.3. It should suggest a materialization that is dynamically stable and is accessible to observations with the required accuracy.


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