Assessment of the quality factor of tribosystems and relationship with tribological characteristics

2020 ◽  
Vol 98 (4) ◽  
pp. 20-26
Author(s):  
V. Vojtov ◽  
◽  
A. Voitov ◽  
Keyword(s):  
Quality Factor ◽  
Experimental Studies ◽  
Propagation Rate ◽  
Operating Conditions ◽  
Maximum Effect ◽  
Surface Layers ◽  
Steady State Operation ◽  
Definition Of ◽  
Friction Surfaces ◽  
The Relationship

The definition of the quality factor of the tribosystem has been further developed, which, unlike the known one, takes into account not only the geometric dimensions of the tribosystem, thermal diffusivity of triboelement materials, lubricating medium and deformation propagation rate in the surface layers of the material, but also the function of changing the rheological properties of the surface layers of materials during running-in and their increase during running-in. Theoretical studies have established that three parameters have the maximum effect on the quality factor: sliding speed, roughness of friction surfaces and lubricating medium. Experimental studies have established the relationship between the value of the quality factor, wear rate and coefficient of friction during steady-state operation of tribosystems. It has been shown that an increase in the figure of quality factor reduces the above parameters, and the criterion itself Qmax is a measure of the potential of the tribosystem adapt to the operating conditions.

scholarly journals The Quality of the Tribosystem as a Factor of Wear Resistance

2018 ◽  
Vol 7 (4.3) ◽  
pp. 25
Author(s):  
Viktor Vojtov ◽  
Abliatif Biekirov ◽  
Anton Voitov
Keyword(s):  
Thermal Diffusivity ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Methodological Approach ◽  
Experimental Studies ◽  
Operating Conditions ◽  
Quality Value ◽  
Definition Of ◽  
The Relationship

The purpose of this work was to develop a criterion for estimating the quality factor of the tribosystem and to assess its effect on wear rate, friction coefficient and run-in time. The basis of the methodological approach when developing a criterion for the quality of the tribosystem is the parameters that take into account the construction of the tribosystem, the thermal diffusivity of materials and the loading conditions of the tribosystems.The definition of the quality of the tribosystem has been further developed, which, unlike the known one, takes into account the geometric dimensions and kinematic scheme of the tribosystem, the thermal diffusivity of materials and the rate of propagation of deformation in the surface layers of the triboelement materials during their contact interaction. Theoretical and experimental studies established the relationship between the quality value, wear rate and the friction coefficient in the process of running-in. It is shown that the increase in quality helps to reduce the above-mentioned parameters.The relationship between the running-in time and the quality value is established. It is shown that the process of running-in can be controlled. To reduce the running-in time, it is necessary to reduce the sliding speed during the transient process and to increase the tribological properties of the lubricating medium. The presented theoretical and experimental studies allow us to state that the quality of tribosystems Q can be a measure of the potential ability of the tribosystem to adapt (adapt) to operating conditions, providing the maximum resource.  

scholarly journals Contact-deformation mechanism of boundary friction

2020 ◽  
Vol 164 ◽  
pp. 14004
Author(s):  
Alexandr Dykha ◽  
Volodymyr Kukhar ◽  
Viktor Artiukh ◽  
Maxim Aleksandrovskiy
Keyword(s):  
Experimental Studies ◽  
Deformation Mechanisms ◽  
Internal Stresses ◽  
Stress And Strain ◽  
Relative Deformation ◽  
Contact Deformation ◽  
Surface Layers ◽  
Friction Units ◽  
Relationship Of ◽  
The Relationship

Research was conducted to determine the effect of lubricants on stress and strain in the contact of metal surfaces. Experiments were carried out on the introduction of a fixed and moving indenter in contact with a dry and lubricated surface.The steel spherical specimen was pressed into a lubricated and dry metal surface. The microstructures of the structure of the surface layer are studied under various conditions of deformation. The diagrams of the relative deformation of the surface layers are constructed. The mechanism of the formation and distribution of internal stresses for dry and greased contact is described. Experimental studies of the introduction of a moving steel indenter into a lubricated surface have been carried out. The relationship of the deformation mechanisms of lubricated surfaces with their wear resistance is determined. The results obtained are recommended for predicting the durability of lubricated friction units according to the criterion of contact strength.

scholarly journals Parametric identification of the mathematical model of the functioning of tribosystems in the conditions of boundary lubrication

2021 ◽  
Vol 101 (3) ◽  
pp. 6-14
Author(s):  
A. Voitov ◽  
Keyword(s):  
Quality Factor ◽  
Time Constant ◽  
Boundary Lubrication ◽  
Rapid Change ◽  
Parametric Identification ◽  
Surface Layers ◽  
Sliding Speed ◽  
External Conditions ◽  
Time Required ◽  
Friction Surfaces

The parametric identification of the tribosystem as an object of modeling the functioning of tribosystems in the conditions of boundary lubrication is performed in the work. Using the analysis of the dimensions of significant factors, expressions are obtained to calculate the gain and time constants. It is established that the coefficient takes into account the degree of influence of the load, sliding speed, tribological characteristics of the lubricating medium on the quality factor of the tribosystem. It is shown that the increase in the coefficient will have a positive effect on the processes inherent in tribosystems during operation. Coefficient – characterizes the magnitude of the change in volumetric wear rate and friction coefficient when changing the magnitude of the load, sliding speed, quality factor of the tribosystem. Coefficient – characterizes the ability of the tribosystem to self-organize when changing the values of the input parameters by rearranging the surface layers of materials from which the triboelements are made during secondary running-in. It is shown that the value of the coefficient is large will contribute to the rapid change in the roughness of the friction surfaces, the restructuring of the structure of the surface layers, the appearance of oxidizing films on the friction surfaces (secondary structures). It is proved that the time constant – this is the time required to change the roughness of the friction surfaces and rearrange the structure of the materials of the surface layers when changing external conditions. Time constant characterizes the time during which there is a stabilization of the temperature gradient by volume of triboelements, taking into account the thermal conductivity of materials when changing external conditions. Time constant characterizes the time during which the tribosystem returns to a steady state of operation after the cessation of the outrageous force, or the time to stabilize the parameters in the new mode of operation. It is proved that the value will be optimal for the process of self-organization. It is shown that one of the factors that can control the value , this is the sliding speed

Probabilistic Estimation of Water Flood Requirement to Control Flow Behind the Casing on Offshore Platforms

2021 ◽  
Author(s):  
Arash Haghshenas ◽  
Emilio Luengo ◽  
Yogesh Bansal ◽  
Geraldo Mijares
Keyword(s):  
Control Flow ◽  
Operating Conditions ◽  
Offshore Platforms ◽  
Control Mechanisms ◽  
Successful Operation ◽  
Operational Conditions ◽  
Reservoir Permeability ◽  
Simulation Based ◽  
Definition Of ◽  
The Relationship

Abstract Recently, flood kill applications have been evaluated to cure blowouts due to gas migration from behind the casing while keeping the well integrity intact for further production. Traditionally, deterministic evaluations are used in planning these operations, ignoring the uncertainties in the characteristics of the gas sources behind the casing. This work focuses on using reservoir simulation-based workflow to evaluate the uncertainty providing probabilistic operating conditions to control the gas rates coming from behind the casing. The results of the simulations are combined to provide general guidelines for performing an effective flood kill operation. The studied parameters are divided in different categories based on their influence/impact on the effective kill. For example, the relationship between the best relief well position and reservoir permeability and anisotropy are studied, and the guidelines for the definition of the best location is identified. Based on the results of the analysis, the optimum required proximity of the wells can be determined. The analysis identifies the main factors for a successful flood kill operation. The situations where flood kill could be beneficial are identified and the success rate could be evaluated. This paper presents a methodology and guidelines for the design of an effective flood kill application. This methodology will help in positioning of the relief well and provide required control mechanisms to increase the chances of a successful operation. The methodology also provides insight on the required operating parameters, such as pump rates and total volume to be injected, for the operation to be successful. In addition, the developed workflow can be updated as more information is gathered while drilling the relief well. This will help in improving the chances of a flood-kill operation while providing tighter controls on the operational conditions.

scholarly journals Contact-deformation mechanics of the interaction of lubricated surfaces

2019 ◽  
Vol 1 ◽  
pp. 15-20
Author(s):  
A Dykha ◽  
S Posonsky1
Keyword(s):  
Wear Resistance ◽  
Experimental Studies ◽  
Deformation Mechanisms ◽  
Internal Stresses ◽  
Relative Deformation ◽  
Contact Deformation ◽  
Surface Layers ◽  
Deformation Mechanics ◽  
Relationship Of ◽  
The Relationship

The questions of the influence of the lubricant on the conditions of deformation in the contact of solids are considered. The steel spherical specimen was pressed into a greased and dry metal surface. The microstructures of the structure of the surface layer are studied under various conditions of deformation. The diagrams of the relative deformation of the surface layers are constructed. The mechanism of the formation and distribution of internal stresses for dry and greased contact is described. Experimental studies of the introduction of a moving steel indenter into a lubricated surface have been carried out. The relationship of the deformation mechanisms of lubricated surfaces with their wear resistance is determined.

Towards the digital land reclamation

2020 ◽  
pp. 5-9
Author(s):  
Sergey Vasil'ev ◽  
Vyacheslav Schedrin ◽  
Aleksandra Slabunova ◽  
Vladimir Slabunov
Keyword(s):  
Retrospective Analysis ◽  
Land Reclamation ◽  
Practical Experience ◽  
Maximum Effect ◽  
Optimal Management ◽  
Scientific Potential ◽  
History Of ◽  
Definition Of ◽  
Further Development ◽  
Full Cooperation

The aim of the research is a retrospective analysis of the history and stages of development of digital land reclamation in Russia, the definition of «Digital land reclamation» and trends in its further development. In the framework of the retrospective analysis the main stages of melioration formation are determined. To achieve the maximum effect of the «digital reclamation» requires full cooperation of practical experience and scientific potential accumulated throughout the history of the reclamation complex, and the latest achievements of science and technology, which is currently possible only through the full digitalization of reclamation activities. The introduction of «digital reclamation» will achieve greater potential and effect in the modernization of the reclamation industry in the «hightech industry», through the use of innovative developments and optimal management decisions.

ADMINISTRATIVE AND LEGAL STATUS OF THE CAPITAL OF UKRAINE - THE HERO CITY OF KYIV AS A GUARANTEE OF THE RIGHTS OF CITIZENS OF UKRAINE AND THE TERRITORIAL COMMUNITY OF THE CITY

2017 ◽  
Author(s):  
Oleksii Chepov ◽  
Keyword(s):  
Legal Status ◽  
Modern World ◽  
Legal Regime ◽  
Legal Doctrine ◽  
City Councils ◽  
The Social ◽  
District Management ◽  
Definition Of ◽  
The Relationship ◽  
The City

The qualitative and clear definition of the legal regime of the capital of Ukraine, the hero city of Kyiv, is influenced by its legislative enshrinement, however, it should be noted that discussions are ongoing and one of the reasons for the unclear legal status of the capital is the ambiguity of current legislation in this area. Separation of the functions of the city of Kyiv, which are carried out to ensure the rights of citizens of Ukraine and the functions that guarantee the rights of the territorial community of the city of Kyiv. In the modern world, in legal doctrine and practice, the capital is understood as the capital of the country, which at the legislative level received this status and, accordingly, is the administrative and political center of the state, which houses the main state bodies and diplomatic missions of other states. It is the identification of the boundaries of the relationship between the competencies of state administrations and local self-government, in practice, often raises questions about their delimitation and ways of regulatory solution. Peculiarities of local self-government in Kyiv city districts are defined in the provisions of the Law on the Capital, which reveal the norms of the Constitution in these legal relations, according to which the issue of organizing district management in cities belongs to city councils. Likewise, it is unregulated by law to lose the particularity of the legal status of the territory of the city. It should be emphasized that the subject of administrative-legal relations is not a certain administrative-territorial entity, but the social group is designated - the territorial community of the city of Kiev, kiyani. Thus, the provisions on the city of Kyiv partially ignore the potential of the territorial community.

Compliance and Conflict of Value in Public Policy Implementation: Comparison between the New Order and the Reformation Era

2018 ◽  
Vol 2 (2) ◽  
pp. 99 ◽  
Author(s):  
Dwiyanto Indiahono ◽  
Erwan Purwanto ◽  
Agus Pramusinto
Keyword(s):  
Public Policy ◽  
Policy Implementation ◽  
Local Level ◽  
Group Discussion ◽  
New Order ◽  
The Reformation ◽  
Public Policy Implementation ◽  
Definition Of ◽  
Conflict Of Value ◽  
The Relationship

This research aims to examine differences in the relationship of bureaucratic and political officials during the New Order (Soeharto’s era) and the Reformation (post-Soeharto) era within the arena of public policy implementation. This is a matter of importance given that there is a change in relations between the two from integration in the New Order to bureaucratic impartiality in the Reformation Era. This study attempts to answer the question: How were the relations of bureaucratic and political officials in the implementation of local level public policy during the New Order and the Reformation Era? A qualitative research has been conducted in Tegal Municipality using the following data collection techniques: interview, focus group discussion, documentation, and observation. Tegal Municipality was selected as the study location because of the unique relationship shown between the mayor and the bureaucracy. Its uniqueness lies in the emergence of bureaucratic officials who dare to oppose political officials, based on their convictions that bureaucratic/public values should be maintained even if it means having to be in direct conflict with political officials. This research indicates that the relationship between bureaucratic and political officials in the arena of local level policy implementation during the New Order was characterized as being full of pressure and compliance, whereas during the Reformation Era bureaucrats have the audacity to hinder policy implementation. Such audacity to thwart policies is considered to have developed from a stance that aims to protect public budget and values in policies. The occurring conflict of values here demonstrates a dichotomy of political and bureaucratic officials that is different from the prevailing definition of politics-administration dichotomy introduced at the onset of Public Administration studies.

A pilot web former designed to study retention-formation relationships

2010 ◽  
Vol 25 (2) ◽  
pp. 185-194
Author(s):  
Anna Svedberg ◽  
Tom Lindström
Keyword(s):  
Pilot Scale ◽  
Operating Conditions ◽  
Montmorillonite Clay ◽  
Speed Ratio ◽  
Good Reproducibility ◽  
Total Solids ◽  
Retention Aids ◽  
Solids Content ◽  
Relationship Of ◽  
The Relationship

Abstract A pilot-scale fourdrinier former has been developed for the purpose of investigating the relationship between retention and paper formation (features, retention aids, dosage points, etc.). The main objective of this publication was to present the R-F (Retention and formation)-machine and demonstrate some of its fields of applications. For a fine paper stock (90% hardwood and 10% softwood) with addition of 25% filler (based on total solids content), the relationship between retention and formation was investigated for a microparticulate retention aid (cationic polyacrylamide together with anionic montmorillonite clay). The retention-formation relationship of the retention aid system was investigated after choosing standardized machine operating conditions (e.g. the jet-to-wire speed ratio). As expected, the formation was impaired when the retention was increased. Since good reproducibility was attained, the R-F (Retention and formation)-machine was found to be a useful tool for studying the relationship between retention and paper formation.

The Concept of Europeanization and Possibilities of its Application to the Analysis of Ukraine-EU Relations

2017 ◽  
pp. 149-160
Author(s):  
Natalia Popova
Keyword(s):  
European Integration ◽  
Theoretical Research ◽  
Member States ◽  
External Governance ◽  
Definition Of ◽  
The Relationship ◽  
Eu Studies ◽  
The Eu

The concept of Europeanization has become quite fashionable in EU studies in recent years. It is often used for the analysis of the relations between the EU and non-member states. The aim of the article is to examine the possibilities of its application in explaining the relationship between the EU and Ukraine. The structure of the article is as follows: firstly, the concept of Europeanization is defined considering such two disputable issues as distinguishing among concepts of Europeanization and European integration as well as Europeanization and EU-ization. Next, the evolution of the theoretical research of Europeanization and definition of this concept are analyzed. Two main mechanisms of Europeanization (conditionality and socialization) are examined. The author considers main approaches to the analysis of the "external" Europeanization emphasizing the concept of "external governance". Three groups of factors which influence the effectiveness of Europeanization are briefly analyzed. And finally, the peculiarities of application of the Europeanization concept to the Ukraine-EU relations are outlined. Keywords: EU, Ukraine, Europeanization, EU-ization, ‘external’ Europeanization, conditionality, socialization, concept of ‘external governance’

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