On the Role of Enduring Contact in Powder Lubrication

2005 ◽  
Vol 128 (1) ◽  
pp. 168-175 ◽  
Author(s):  
J. Y. Jang ◽  
M. M. Khonsari
Keyword(s):  
Analytical Solution ◽  
Flow Velocity ◽  
Volume Fraction ◽  
Flow Characteristics ◽  
Kinetic Regime ◽  
Governing Equations ◽  
Wide Range ◽  
Fraction Distribution ◽  
Powder Lubrication

This paper is devoted to a study of the enduring contact between granules of powder lubricants in an effort to better understand the flow characteristics of powder lubricants. Appropriate formulation of the governing equations is reported that can be used for prediction of the flow velocity, pseudo temperature, and volume fraction distribution of powders for a wide range of operating speeds. A set of parametric simulations and a limiting analytical solution is presented for predicting the behavior of a powder lubricant under low operating speeds when the enduring contact tends to dominate the kinetic regime. The limiting solution shows that below a certain sliding speed the volume fraction remains unchanged due to the effect of the enduring contact. It is also shown that below this limiting speed the enduring contact plays a major role and should not be neglected.

scholarly journals Wave Dispersion Analysis of Fluid Conveying Nanocomposite Shell Reinforced by MWCNTs Considering the Effect of Waviness and Agglomeration Efficiency

Polymers ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 153
Author(s):  
Mohammad Alkhedher ◽  
Pouyan Talebizadehsardari ◽  
Arameh Eyvazian ◽  
Afrasyab Khan ◽  
Naeim Farouk
Keyword(s):  
Cylindrical Shell ◽  
Flow Velocity ◽  
Volume Fraction ◽  
Wave Dispersion ◽  
Orientation Factor ◽  
Axially Symmetric ◽  
Governing Equations ◽  
Random Orientation ◽  
Navier Stokes Equation ◽  
Wide Range

The current paper is aimed to investigate the effects of waviness, random orientation, and agglomeration factor of nanoreinforcements on wave propagation in fluid-conveying multi-walled carbon nanotubes (MWCNTs)-reinforced nanocomposite cylindrical shell based on first-order shear deformable theory (FSDT). The effective mechanical properties of the nanocomposite cylindrical shell are estimated employing a combination of a novel form of Halpin-Tsai homogenization model and rule of mixture. Utilized fluid flow obeys Newtonian fluid law and it is axially symmetric and laminar flow and it is considered to be fully developed. The effect of flow velocity is explored by implementing Navier-Stokes equation. The kinetic relations of nanocomposite shell are calculated via FSDT. Moreover, the governing equations are derived using the Hamiltonian approach. Afterward, a method which solves problems analytically is applied to solve the obtained governing equations. Effects of a wide range of variants such as volume fraction of MWCNTs, radius to thickness ratio, flow velocity, waviness factor, random orientation factor, and agglomeration factor on the phase velocity and wave frequency of a fluid conveying MWCNTs-reinforced nanocomposite cylindrical shell were comparatively illustrated and the results were discussed in detail.

Flow Characteristics of a Powder Lubricant Sheared Between Parallel Plates

1999 ◽  
Vol 122 (1) ◽  
pp. 147-155 ◽  
Author(s):  
Lei Zhou ◽  
M. M. Khonsari
Keyword(s):  
Energy Equation ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Flow Characteristics ◽  
Realistic Model ◽  
Granular Temperature ◽  
Parallel Plates ◽  
Governing Equations ◽  
Simulation Results ◽  
Powder Lubrication

This paper is devoted to the understanding of the flow characteristics of a powder lubricant. An accurate and realistic model is introduced to investigate the mechanism of powder lubrication sheared between two infinitely wide parallel plates. In this theory, the solid volume fraction, v, together with flow velocity and granular temperature are directly obtained from a set of complete governing equations (mass, momentum and pseudo-energy conservation equations). The boundary conditions take into account the effect of slip velocity and the wall surface roughness. A set of parametric simulation results is presented. It is shown that viscous dissipation plays an important role in the pseudo-energy equation. [S0742-4787(00)01901-9]

scholarly journals Microstructure and magnetic properties of Nd-Fe-B-(Re, Ti) alloys

Nukleonika ◽  
2015 ◽  
Vol 60 (1) ◽  
pp. 29-33
Author(s):  
Mariusz Hasiak
Keyword(s):  
Magnetic Properties ◽  
Phase Composition ◽  
Volume Fraction ◽  
Magnetic Characteristics ◽  
Ti Alloys ◽  
Wide Range ◽  
Magnetically Hard ◽  
Ti Addition ◽  
Microstructure And Magnetic Properties

Abstract The microstructure and magnetic properties of nanocomposite hard magnetic Nd-Fe-B-(Re, Ti) materials with different Nd and Fe contents are studied. The role of Re and Ti addition in phase composition and volume fraction of the Nd-Fe-B phase is determined. All samples are annealed at the same temperature of 993 K for 10 min. Mössbauer spectroscopy shows that the addition of 4 at.% of Re to the Nd8Fe78B14 alloy leads to creation of an ineligible amount of the magnetically hard Nd2Fe14B phase. Moreover, the microstructure and magnetic characteristics recorded in a wide range of temperatures for the Nd8Fe79−xB13Mx (x = 4; M = Re or Ti) alloys are also analyzed.

Flow Characteristics of a Powder Lubricant in a Slider Bearing

2001 ◽  
Author(s):  
Manjunath Pappur ◽  
M. M. Khonsari
Keyword(s):  
Slip Velocity ◽  
Thrust Bearing ◽  
Volume Fraction ◽  
Flow Characteristics ◽  
Slider Bearing ◽  
Systematic Development ◽  
Powder Lubrication ◽  
Insight Into ◽  
Theory And Experiment ◽  
Good Agreement

Abstract This paper deals with a systematic development of theory of powder lubrication with the appropriate formalism based on the fundamentals of fluid mechanics. The theory is capable of predicting flow velocity, fluctuation (pseudo-temperature), powder volume fraction, and slip velocity at the boundaries. An extensive set of parametric simulations covering particle size, surface roughness, volumetric flow, load and speed are performed to gain insight into the performance of a powder lubricated thrust bearing. The results of simulations are compared to the published experimental results. Good agreement between the theory and experiment attests to the capability of the model and its potential for design of powder lubricated bearings.

HUMUS FRACTION RATIOS AS A MEANS OF DISCRIMINATING BETWEEN HORIZON TYPES

1980 ◽  
Vol 60 (2) ◽  
pp. 219-229 ◽  
Author(s):  
L. E. LOWE
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Carbon Content ◽  
Fulvic Acid ◽  
Soil Classification ◽  
Acid Fraction ◽  
Humus Fraction ◽  
Wide Range ◽  
Fraction Distribution

Humus fraction distribution in a wide range of horizon samples was examined by measuring carbon content in humic acid (Ch), in fulvic acid (Cf) and in the strongly colored polyphenolic component of the fulvic acid fraction (Ca). Fraction distribution was described by the ratios Ch/Cf and Ca/Cf. It was concluded that humus fraction ratios were related to horizon types as used in the Canadian System of Soil Classification, and were effective in discriminating between certain horizon types, particularly between Luvisolic Bt and Podzolic Bf. The results also suggested that humus fraction ratios may be effective in separating distinct sub-populations within Ah horizons and Bf horizons in general, based on qualitative differences in organic matter present. Aspects of the role of humus fractions in soil genesis are discussed.

The Problem of Identifying and Modeling the Relationship between Monetary Factor and Inflation in the Russian Economy

2008 ◽  
pp. 61-76
Author(s):  
A. Porshakov ◽  
A. Ponomarenko
Keyword(s):  
Money Supply ◽  
Money Demand ◽  
Russian Economy ◽  
Long Run ◽  
Complex Approach ◽  
Wide Range ◽  
Long Time ◽  
The Relationship ◽  
Supply Side Factors

The role of monetary factor in generating inflationary processes in Russia has stimulated various debates in social and scientific circles for a relatively long time. The authors show that identification of the specificity of relationship between money and inflation requires a complex approach based on statistical modeling and involving a wide range of indicators relevant for the price changes in the economy. As a result a model of inflation for Russia implying the decomposition of inflation dynamics into demand-side and supply-side factors is suggested. The main conclusion drawn is that during the recent years the volume of inflationary pressures in the Russian economy has been determined by the deviation of money supply from money demand, rather than by money supply alone. At the same time, monetary factor has a long-run spread over time impact on inflation.

Introduction: Emotion, History and the Arts

2018 ◽  
Vol 7 (2) ◽  
pp. 117-128 ◽  
Author(s):  
Erin Sullivan ◽  
Marie Louise Herzfeld-Schild
Keyword(s):  
Historical Change ◽  
Carson Mccullers ◽  
Emotional Life ◽  
Review Section ◽  
The Arts ◽  
Wide Range ◽  
War Correspondents ◽  
History Of ◽  
Johan Huizinga

This introduction surveys the rise of the history of emotions as a field and the role of the arts in such developments. Reflecting on the foundational role of the arts in the early emotion-oriented histories of Johan Huizinga and Jacob Burkhardt, as well as the concerns about methodological impressionism that have sometimes arisen in response to such studies, the introduction considers how intensive engagements with the arts can open up new insights into past emotions while still being historically and theoretically rigorous. Drawing on a wide range of emotionally charged art works from different times and places—including the novels of Carson McCullers and Harriet Beecher-Stowe, the private poetry of neo-Confucian Chinese civil servants, the photojournalism of twentieth-century war correspondents, and music from Igor Stravinsky to the Beatles—the introduction proposes five ways in which art in all its forms contributes to emotional life and consequently to emotional histories: first, by incubating deep emotional experiences that contribute to formations of identity; second, by acting as a place for the expression of private or deviant emotions; third, by functioning as a barometer of wider cultural and attitudinal change; fourth, by serving as an engine of momentous historical change; and fifth, by working as a tool for emotional connection across communities, both within specific time periods but also across them. The introduction finishes by outlining how the special issue's five articles and review section address each of these categories, while also illustrating new methodological possibilities for the field.

Short Films from a Small Nation

2018 ◽  
Author(s):  
C. Claire Thomson
Keyword(s):  
Public Information ◽  
Industrial Process ◽  
Actor Network Theory ◽  
Documentary Films ◽  
Wide Range ◽  
Short Films ◽  
Post War ◽  
The 1960S ◽  
Art And Architecture

The first book-length study in English of a national corpus of state-sponsored informational film, this book traces how Danish shorts on topics including social welfare, industry, art and architecture were commissioned, funded, produced and reviewed from the inter-war period to the 1960s. For three decades, state-sponsored short filmmaking educated Danish citizens, promoted Denmark to the world, and shaped the careers of renowned directors like Carl Th. Dreyer. Examining the life cycle of a representative selection of films, and discussing their preservation and mediation in the digital age, this book presents a detailed case study of how informational cinema is shaped by, and indeed shapes, its cultural, political and technological contexts.The book combines close textual analysis of a broad range of films with detailed accounts of their commissioning, production, distribution and reception in Denmark and abroad, drawing on Actor-Network Theory to emphasise the role of a wide range of entities in these processes. It considers a broad range of genres and sub-genres, including industrial process films, public information films, art films, the city symphony, the essay film, and many more. It also maps international networks of informational and documentary films in the post-war period, and explores the role of informational film in Danish cultural and political history.

Quantitative and Qualitative Methods of Studying the Processes of Socialization of a Modern Teenager

2020 ◽  
pp. 102-109
Author(s):  
Svetlana Alekseevna Raschetina ◽  
Keyword(s):  
Research Methods ◽  
Interpersonal Relations ◽  
Internet Communication ◽  
Socialization Process ◽  
Wide Range ◽  
The Family ◽  
Modern Family ◽  
Making Friends ◽  
Main Support

Relevance and problem statement. Modern unstable society is characterized by narrowing the boundaries of controlled socialization and expanding the boundaries of spontaneous socialization of a teenager based on his immersion in the question arises about the importance of the family in the process of socialization of a teenager in the conditions of expanding the space of socialization. There is a need to study the role of the family in this process, to search, develop and test research methods that allow us to reveal the phenomenon of socialization from the side of its value characteristics. The purpose and methodology of the study: to identify the possibilities of a systematic and anthropological methodology for studying the role of the family in the process of socialization of adolescents in modern conditions, testing research methods: photo research on the topic “Ego – I” (author of the German sociologist H. Abels), profile update reflexive processes (by S. A. Raschetina). Materials and results of the study. The study showed that for all the problems that exist in the family of the perestroika era and in the modern family, it acts for a teenager as a value and the first (main) support in the processes of socialization. The positions well known in psychology about the importance of interpersonal relations in adolescence for the formation of attitudes towards oneself as the basis of socialization are confirmed. Today, the frontiers of making friends have expanded enormously on the basis of Internet communication. The types of activities of interest to a teenager (traditional and new ones related to digitalization) are the third pillar of socialization. Conclusion. The “Ego – I” method of photo research has a wide range of possibilities for quantitative and qualitative analysis of the socialization process to identify the value Pillars of this process.

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