On the Mechanism of Contact Between Metal Surfaces—The Penetrating Depth and the Average Clearance

1965 ◽  
Vol 87 (3) ◽  
pp. 666-672 ◽  
Author(s):  
Tadasu Tsukizoe ◽  
Terumasa Hisakado
Keyword(s):  
Metal Surfaces ◽  
Applied Load ◽  
Distribution Curve ◽  
The Other ◽  
Real Contact Area ◽  
Profile Curve ◽  
Air Leakage ◽  
Real Contact ◽  
The One ◽  
Good Agreement

The analysis of the mechanism of air leakage through the interstices between metal surfaces in contact or of the mechanism of thermal resistance between them is dependent on the average clearance between opposite surfaces or on the distribution of the real contact area; i.e., the mechanism of contact. Assuming that the distribution curve obtained from the profile curve of the surface has a normal distribution, the relation between the applied load and the average clearance or the penetrating depth, i.e., the distance through which the one surface moves into the other surface, is obtained theoretically. A comparison of calculated values based on this theory with experimental data shows good agreement.

Decreasing the Adhesion Effect of Surfaces Using Graphite Pellicle Deposition through Electric Discharges in Pulse

2014 ◽  
Vol 1036 ◽  
pp. 172-177 ◽  
Author(s):  
Pavel Topala ◽  
Vitalie Besliu ◽  
Laurentiu Marin
Keyword(s):  
Experimental Research ◽  
Metal Surfaces ◽  
The Other ◽  
Electric Discharges ◽  
Polyurethane Adhesive ◽  
Test Pieces ◽  
Other Hand ◽  
The One ◽  
Adhesion Effect

The paper aims at studying the phenomenon of adhesion between the graphite pellicles deposited through electric discharges in pulse (EDI) with metal surfaces subjected to processing on the one hand and on the other hand the adhesion of this pellicle with a polyurethane adhesive. Experimental research has shown that, when the surfaces are not treated, the shear occurs in the adhesive, when the test pieces are covered with graphite pellicles the shear occurs on the surface that separates the pellicle from the adhesive. It has been stated experimentally that graphite pellicles deposited through electric discharges in pulse decrease the adhesion between the mating surfaces by at least 40% compared to the not treated surfaces.

Recycling, Recovery and Improvement of Properties of Ceramic Tile Manufacturing by Adding Two Types of Glass in Clay Mixtures

2012 ◽  
Vol 323-325 ◽  
pp. 275-280 ◽  
Author(s):  
Halima Chemani
Keyword(s):  
Comparative Study ◽  
Mechanical Strength ◽  
Ceramic Tile ◽  
Industrial Waste ◽  
Waste Glass ◽  
The Other ◽  
The One ◽  
Good Agreement

Today, recycling industrial waste plays a major role in our society. Waste is used as additive in the production of a certain number of products. It enables to reduce the costing price per piece and to enhance some of the properties of the material, and to reduce pollution problems. To meet the various criteria, and manufacturing requirements of contemporary ceramic tile and bring a solution to our environment, an addition of waste glass from lamps public lighting and neon (cullet) is incorporated in various ceramic masse for substituted a feldspar. A comparative study is made between the properties obtained with each type of waste on the one hand and the other with the properties of tile produced in the industry. It was found that the tiles made with waste glass lighting lamps offer higher mechanical strength than that obtained with the feldspar and a good agreement between the shard - enamel. Although the value of strength obtained with the waste of neon is lower than that obtained with the first type of glass. The latter always remains higher than that of industrial value.

scholarly journals FRACTURE MECHANICS SIMPLE CALCULATIONS TO EXPLAIN SMALL REDUCTION OF THE REAL CONTACT AREA UNDER SHEAR

2018 ◽  
Vol 16 (1) ◽  
pp. 87 ◽  
Author(s):  
Michele Ciavarella
Keyword(s):  
Fracture Mechanics ◽  
Contact Area ◽  
Real Contact Area ◽  
Shear Load ◽  
Small Reduction ◽  
Real Contact ◽  
Area Reduction ◽  
Simple Equations ◽  
Smooth Sphere ◽  
Good Agreement

In a very recent paper, Sahli and coauthors [12] (R. Sahli et al., 2018, “Evolution of real contact area under shear”, PNAS, 115(3), pp. 471-476) studied the contact area evolution for macroscopic smooth spheres under shear load in presence of adhesion. It was found that contact area AA reduces quadratically with respect to shear load T, i.e. A=A0-alphaAT2, where A0 is the contact area with no shearing, and alphaA is the "area reduction parameter" found to be approximately proportional to A0-3/2 across 4 orders of magnitude of A0. In this note we focus on the smooth sphere/plane contact because we believe that the case of a rough contact requires separate investigations, and we use a known model of fracture mechanics, which contains a fitting parameter b which governs the interplay between fractures modes, in order to find very good agreement between the data and the analytical predictions, developing relatively simple equations. The interaction with modes is limited.

A Multilevel Model for Elastic-Plastic Contact Between a Sphere and a Flat Rough Surface

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
F. Steven Wang ◽  
Joseph M. Block ◽  
W. Wayne Chen ◽  
Ashlie Martini ◽  
Kun Zhou ◽  
...  
Keyword(s):  
Contact Area ◽  
Multilevel Model ◽  
Coarse Grid ◽  
Real Contact Area ◽  
Machined Surface ◽  
Elastic Plastic ◽  
Real Contact ◽  
Calculated Load ◽  
Surface Deflection ◽  
Good Agreement

Elastic-plastic contact of a smooth sphere and a half-space with a real machined surface is simulated using an integration-based multilevel contact model. The total surface deflection is composed of bulk and asperity deformations. They are calculated at the global and the asperity level, respectively, which are connected through the asperity-supporting load. With this new model, the accurate contact area and contact pressure under a given load are quickly predicted using a relatively coarse grid system. The calculated load-area curve shows good agreement with the experimental data. Finally, the effects of the surface topography, including roughness and the asperity radius, upon the real contact area are analyzed.

Note on Selection of Coordinate Systems for Geodynamics

1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen
Keyword(s):  
Sea Level ◽  
The Other ◽  
Coordinate Systems ◽  
Mean Sea Level ◽  
The Earth ◽  
The One ◽  
Static Systems ◽  
Selection Of

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.

Stories and the Self

2020 ◽  
Vol 32 (2) ◽  
pp. 47-58 ◽  
Author(s):  
Stefan Krause ◽  
Markus Appel
Keyword(s):  
Meta Analysis ◽  
The Self ◽  
The Other ◽  
Lower Degree ◽  
Contrast Effects ◽  
Self Perception ◽  
Self Perceptions ◽  
Other Hand ◽  
The One ◽  
Implicit And Explicit

Abstract. Two experiments examined the influence of stories on recipients’ self-perceptions. Extending prior theory and research, our focus was on assimilation effects (i.e., changes in self-perception in line with a protagonist’s traits) as well as on contrast effects (i.e., changes in self-perception in contrast to a protagonist’s traits). In Experiment 1 ( N = 113), implicit and explicit conscientiousness were assessed after participants read a story about either a diligent or a negligent student. Moderation analyses showed that highly transported participants and participants with lower counterarguing scores assimilate the depicted traits of a story protagonist, as indicated by explicit, self-reported conscientiousness ratings. Participants, who were more critical toward a story (i.e., higher counterarguing) and with a lower degree of transportation, showed contrast effects. In Experiment 2 ( N = 103), we manipulated transportation and counterarguing, but we could not identify an effect on participants’ self-ascribed level of conscientiousness. A mini meta-analysis across both experiments revealed significant positive overall associations between transportation and counterarguing on the one hand and story-consistent self-reported conscientiousness on the other hand.

Radioimmunotherapy for treatment of acute myeloid leukaemia and myelodysplastic syndrome

2005 ◽  
Vol 44 (03) ◽  
pp. 107-117
Author(s):  
R. G. Meyer ◽  
W. Herr ◽  
A. Helisch ◽  
P. Bartenstein ◽  
I. Buchmann
Keyword(s):  
Acute Myeloid Leukaemia ◽  
Myeloid Leukaemia ◽  
Primary Tumour ◽  
The Other ◽  
Haematopoietic Stem Cell ◽  
Other Hand ◽  
Primary Reduction ◽  
The One ◽  
Acute Myeloid

SummaryThe prognosis of patients with acute myeloid leukaemia (AML) has improved considerably by introduction of aggressive consolidation chemotherapy and haematopoietic stem cell transplantation (SCT). Nevertheless, only 20-30% of patients with AML achieve long-term diseasefree survival after SCT. The most common cause of treatment failure is relapse. Additionally, mortality rates are significantly increased by therapy-related causes such as toxicity of chemotherapy and complications of SCT. Including radioimmunotherapies in the treatment of AML and myelodyplastic syndrome (MDS) allows for the achievement of a pronounced antileukaemic effect for the reduction of relapse rates on the one hand. On the other hand, no increase of acute toxicity and later complications should be induced. These effects are important for the primary reduction of tumour cells as well as for the myeloablative conditioning before SCT.This paper provides a systematic and critical review of the currently used radionuclides and immunoconjugates for the treatment of AML and MDS and summarizes the literature on primary tumour cell reductive radioimmunotherapies on the one hand and conditioning radioimmunotherapies before SCT on the other hand.

Das Ende der Postdemokratie, den Pessimismus überwinden.

2017 ◽  
Vol 47 (188) ◽  
pp. 487-494
Author(s):  
Daniel Mullis
Keyword(s):  
Political Thought ◽  
Social Dynamics ◽  
Social Conditions ◽  
The Other ◽  
Economic Decline ◽  
Far Right ◽  
Windows Of Opportunity ◽  
Political Events ◽  
Political Struggles ◽  
The One

In recent years, political and social conditions have changed dramatically. Many analyses help to capture these dynamics. However, they produce political pessimism: on the one hand there is the image of regression and on the other, a direct link is made between socio-economic decline and the rise of the far-right. To counter these aspects, this article argues that current political events are to be understood less as ‘regression’ but rather as a moment of movement and the return of deep political struggles. Referring to Jacques Ranciere’s political thought, the current conditions can be captured as the ‘end of post-democracy’. This approach changes the perspective on current social dynamics in a productive way. It allows for an emphasis on movement and the recognition of the windows of opportunity for emancipatory struggles.

Tolerance is theoretical and practical principles

1996 ◽  
pp. 13-23
Author(s):  
Mykhailo Babiy
Keyword(s):  
Religious Diversity ◽  
The Other ◽  
Nodal Points ◽  
Characteristic Features ◽  
The One ◽  
Ukrainian Society

Political ideological pluralism, religious diversity are characteristic features of modern Ukrainian society. On the one hand, multiculturalism, socio-political, religious differentiation of the latter appear as important characteristics of its democracy, as a practical expression of freedom, on the other - as a factor that led to the deconsocialization of society, gave rise to "nodal points" of tension, confrontational processes, in particular, in political and religious spheres.

The Salvage of Ideas: Schumpeter and the Core Problems Still Confronting Economics

2003 ◽  
pp. 15-26
Author(s):  
P. Wynarczyk
Keyword(s):  
The Other ◽  
The Core ◽  
Other Hand ◽  
The One

Two aspects of Schumpeter' legacy are analyzed in the article. On the one hand, he can be viewed as the custodian of the neoclassical harvest supplementing to its stock of inherited knowledge. On the other hand, the innovative character of his works is emphasized that allows to consider him a proponent of hetherodoxy. It is stressed that Schumpeter's revolutionary challenge can lead to radical changes in modern economics.

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