Log in

Relevant bibliographies by topics / Dimension du contact / Journal articles

To see the other types of publications on this topic, follow the link: Dimension du contact.

Journal articles on the topic 'Dimension du contact'

Author: Grafiati

Published: 6 July 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Dimension du contact.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

McNevin, S. C., and M. Cerullo. "Contact etch scaling with contact dimension." Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films 16, no. 3 (May 1998): 1514–18. http://dx.doi.org/10.1116/1.581179.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Liou, J. L., and J. F. Lin. "A Microcontact Model Developed for Asperity Heights with a Variable Profile Fractal Dimension, A Surface Fractal Dimension, Topothesy, and Non-Gaussian Distribution." Journal of Mechanics 25, no. 1 (March 2009): 103–15. http://dx.doi.org/10.1017/s1727719100003646.

Full text

Abstract:

AbstractThe cross sections formed by the contact asperities of two rough surfaces at an interference are islandshaped, rather than having the commonly assumed circular contour. These island-shaped contact surface contours show fractal behavior with a profile fractal dimension Ds. The surface fractal dimension for the asperity heights is defined as D and the topothesy is defined as G. In the study of Mandelbrot, the relationship between D and Ds was given as D = Ds + 1 if these two fractal dimensions are obtained before contact deformation. In the present study, D, G, and Ds are considered to be varying with the mean separation (or the interference at the rough surface) between two contact surfaces. The D-Ds relationships for the contacts at the elastic, elastoplastic, and fully plastic deformations are derived and the inceptions of the elastoplastic deformation regime and the fully plastic deformation regime are redefined using the equality of two expressions established in two different ways for the number of contact spots (N). The contact parameters, including the total contact force and the real contact area, were evaluated when the size distribution functions (n) for the three deformation regimes were available. The results indicate that both the D and Ds parameters in these deformation regimes increased with increasing the mean separation (d*). The initial plasticity index before contact deformation (ψ)0 is also a factor of importance to the predictions of the contact load (F*t) and contact area (At*) between the model of variable D and G, non-Gaussian asperity heights and circular contact area and the present model of variable D and G, non-Gaussian asperity heights and fractal contact area.

APA, Harvard, Vancouver, ISO, and other styles

3

Liu, Kaian, Yingqiang Xu, Zhenghai Wu, and Li Xiao. "Evolution Behavior Analysis of Normal Contact Stiffness of Fractal Surface under Loading and Unloading." Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University 38, no. 6 (December 2020): 1188–97. http://dx.doi.org/10.1051/jnwpu/20203861188.

Full text

Abstract:

In order to analyze the evolution of normal contact stiffness under loading and unloading, an accurate elastic-plastic contact finite element model between rigid plane and fractal surface is established by introducing the equivalent metal matrix deformation in terms of the modified Weierstrass-Mandelbrot function. The effects of the fractal dimension, scale parameter, material properties on the normal contact stiffness were discussed. A method for evaluating the normal contact stiffness was proposed to analyze the evolution of the normal contact stiffness. Numerical simulation shows that there is a positive power function relationship between the normal contact stiffness and the load of fractal surface. Under the same load, at the fractal dimensions (D) of 2.4-2.7 and scale parameters (G) of 1.36×10-13-1.36×10-10 m, the loading normal contact stiffness increases with the increasing of fractal dimension and tangent modulus, but decreases with the increasing of scale parameter. The unloading normal contact stiffness increases with the material strengthening, and the variation amplitude is positively correlated with the fractal dimension, and negatively correlated with the scale parameters and tangent modulus.

APA, Harvard, Vancouver, ISO, and other styles

4

Budhraja, Vinay, Srinivas Devayajanam, and Prakash Basnyat. "Simulation Results: Optimization of Contact Ratio for Interdigitated Back-Contact Solar Cells." International Journal of Photoenergy 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/7818914.

Full text

Abstract:

In the fabrication of interdigitated back contact (IBC) solar cells, it is very important to choose the right size of contact to achieve the maximum efficiency. Line contacts and point contacts are the two possibilities, which are being chosen for IBC structure. It is expected that the point contacts would give better results because of the reduced recombination rate. In this work, we are simulating the effect of contact size on the performance of IBC solar cells. Simulations were done in three dimension using Quokka, which numerically solves the charge carrier transport. Our simulation results show that around 10% of contact ratio is able to achieve optimum cell efficiency.

APA, Harvard, Vancouver, ISO, and other styles

5

Shi, Li Wan, Duan Yi Wang, Julius Masley, and Shu Wen Zhang. "Comparison Analysis of the Aggregate Contact Characteristics between Skeleton-Dense and Suspended-Dense Structure Asphalt Mixture." Applied Mechanics and Materials 470 (December 2013): 889–92. http://dx.doi.org/10.4028/www.scientific.net/amm.470.889.

Full text

Abstract:

The contact between aggregates is an important feature of asphalt mixture skeleton. By comparing skeleton-dense and suspended-dense structure asphalt mixture test results, this paper studied the distribution characteristics of coarse aggregate contacts by using two-dimension digital image processing technique. The results indicate that skeleton-dense asphalt mixture has more homogeneous distribution of contact points, and a relatively stable skeleton structure than suspended-dense mixture. In two-dimension image, homogeneous distribution of contact points and little unrestrained coarse aggregates are two evident characteristics of asphalt mixture with good rutting resistance. The rutting resistance of asphalt mixture has no correlation with contact points, but is related to the spatial distribution of the contact points.

APA, Harvard, Vancouver, ISO, and other styles

6

Chacón-Cuberos, Ramón, Félix Zurita-Ortega, Eduardo García-Marmol, and Manuel Castro-Sánchez. "Autoconcepto multidimensional según práctica deportiva en estudiantes universitarios de Educación Física de Andalucía (Multidimensional self-concept depending on sport practice in university students of Physical Education from Andalucía)." Retos, no. 37 (August 3, 2019): 174–80. http://dx.doi.org/10.47197/retos.v37i37.71861.

Full text

Abstract:

El presente estudio se realiza en una muestra de 775 estudiantes universitarios que cursan la mención en Educación Física (EF) del Grado en Educación Primaria en la comunidad autónoma de Andalucía. Se pretende analizar las diferentes dimensiones del autoconcepto en base al tipo de deporte practicado y la frecuencia de práctica de Actividad Física (AF) en una muestra de futuros docentes en EF. Como principales instrumentos se emplean los cuestionarios Autoconcepto Forma-5 y PAQ-A. Los resultados muestran que los jóvenes que poseen un mayor autoconcepto general son los que practican deportes colectivos sin contacto. En relación al autoconcepto social, se observó que los participantes que practicaban deportes colectivos sin contacto obtenían las puntuaciones más elevadas, dándose la misma tendencia en la dimensión familiar del autoconcepto. Para la dimensión emocional son los estudiantes que practican deportes colectivos con contacto los que reflejan las mayores puntuaciones, observándose la misma tendencia para el autoconcepto físico. En relación al nivel de práctica de AF, se ha demostrado que aquellos estudiantes que practican deportes individuales con contacto son los que muestran la mayor frecuencia. Asimismo, poseer un mayor autoconcepto físico, social y emocional se asociaba a mayores niveles de práctica de AF.Abstract. The present study was carried out in a sample of 775 university students who attend the Physical Education in Primary Education degree from the Autonomous Community of Andalusia. It aims to analyse the different dimensions of self-concept based on the type of sport practiced and the frequency of Physical Activity in a sample of future teachers in Physical Education. The instruments used were the Self-concept Form-5 and PAQ-A questionnaires. The results show that respondents who have a greater general self-concept are those who practice collective sports without contact. Regarding social self-concept, the participants who practiced collective sports without contact obtained the highest scores, the same tendency being observed in the family dimension of self-concept. Regarding the emotional dimension, students who practice collective sports with contact display the highest scores, the same tendency being observed in physical self-concept. In relation to physical activity levels, students who practice individual sports with contact show the highest frequency. Moreover, having a greater physical, social, and emotional self-concept was associated with higher levels of physical activity.

APA, Harvard, Vancouver, ISO, and other styles

7

Kokoszka, Andrzej. "The Axiological Dimension of Psychiatric Contact." Psychiatry 54, no. 4 (November 1991): 404–12. http://dx.doi.org/10.1080/00332747.1991.11024569.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Duchemin, David. "Quaternionic contact structures in dimension 7." Annales de l’institut Fourier 56, no. 4 (2006): 851–85. http://dx.doi.org/10.5802/aif.2203.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Li, Tian-Jun, and Cheuk Yu Mak. "The Kodaira Dimension of Contact 3-Manifolds and Geography of Symplectic Fillings." International Mathematics Research Notices 2020, no. 17 (July 24, 2018): 5428–49. http://dx.doi.org/10.1093/imrn/rny166.

Full text

Abstract:

Abstract We introduce the Kodaira dimension of contact 3-manifolds and establish some basic properties. Contact 3-manifolds with distinct Kodaira dimensions behave differently when it comes to the geography of various kinds of symplectic fillings. On the other hand, we also prove that, given any contact 3-manifold, there is a lower bound of $2\chi +3\sigma $ for all of its minimal symplectic fillings. This is motivated by Stipsicz’s result in [38] for Stein fillings. Finally, we discuss various aspects of exact self-cobordisms of fillable contact 3-manifolds.

APA, Harvard, Vancouver, ISO, and other styles

10

Francis, Mathew C., and Daniel Gonçalves. "Dushnik-Miller dimension of contact systems of d-dimensional boxes." Electronic Notes in Discrete Mathematics 61 (August 2017): 467–73. http://dx.doi.org/10.1016/j.endm.2017.06.075.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Roederer, Claire. "A Contribution to Conceptualizing the Consumption Experience: Emergence of the Dimensions of an Experience through Life Narratives." Recherche et Applications en Marketing (English Edition) 27, no. 3 (September 2012): 81–95. http://dx.doi.org/10.1177/205157071202700304.

Full text

Abstract:

The notion of consumption experience still suffers from a lack of conceptualization. This inductive study, based on the analysis of life narratives, is an attempt to remedy the problem. It identifies four dimensions of a consumption experience. The «praxeological» dimension is action related. The «hedonico-sensorial» dimension concerns a sensorial and thymic evaluation of the context. The «rhetoric» dimension deals with the meaning of an experience. The fourth dimension highlights the relationship with time. These dimensions contribute to a better conceptualization of an experience through remembrance and consequently to closer contact with the client. They can be considered as levers for action to create or strengthen the competitive edge attached to an experience offer.

APA, Harvard, Vancouver, ISO, and other styles

12

Kainer, G. B. "Contact errors in precision linear-dimension measurement." Measurement Techniques 35, no. 2 (February 1992): 177–79. http://dx.doi.org/10.1007/bf00978869.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Kwon, Jung-Hwan, and Jin-Suk Pak. "(n + 1)-DIMENSIONAL, CONTACT CR-SUBMANIFOLDS OF (n - 1) CONTACT CR-DIMENSION IN A SASAKIAN SPACE FORM." Communications of the Korean Mathematical Society 17, no. 3 (July 1, 2002): 519–29. http://dx.doi.org/10.4134/ckms.2002.17.3.519.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Rukimbira, Philippe. "Rank andk-nullity of contact manifolds." International Journal of Mathematics and Mathematical Sciences 2004, no. 20 (2004): 1025–34. http://dx.doi.org/10.1155/s0161171204309142.

Full text

Abstract:

We prove that the dimension of the1-nullity distributionN(1)on a closed Sasakian manifoldMof ranklis at least equal to2l−1provided thatMhas an isolated closed characteristic. The result is then used to provide some examples ofk-contact manifolds which are not Sasakian. On a closed,2n+1-dimensional Sasakian manifold of positive bisectional curvature, we show that either the dimension ofN(1)is less than or equal ton+1orN(1)is the entire tangent bundleTM. In the latter case, the Sasakian manifoldMis isometric to a quotient of the Euclidean sphere under a finite group of isometries. We also point out some interactions betweenk-nullity, Weinstein conjecture, and minimal unit vector fields.

APA, Harvard, Vancouver, ISO, and other styles

15

Wang, S., and K. Komvopoulos. "A Fractal Theory of the Temperature Distribution at Elastic Contacts of Fast Sliding Surfaces." Journal of Tribology 117, no. 2 (April 1, 1995): 203–14. http://dx.doi.org/10.1115/1.2831227.

Full text

Abstract:

The statistical temperature distribution at fast sliding interfaces is studied by characterizing the surfaces as fractals and considering elastic deformation of the asperities. The fractions of the real contact area in the slow, transitional, and fast sliding regimes are determined based on the microcontact size distribution. For a smooth surface in contact with a rough surface, the temperature rises at the real contact area are determined under the assumption that most of the frictional heat is transferred to one of the surfaces. The interfacial temperature rises are bounded by the maximum temperature rise at the largest microcontact when the fractal dimension is 1.5 or less, and are unbounded when it is greater than 1.5. Higher temperature rises occur at larger microcontacts when the fractal dimension is less than 1.5, and at smaller microcontacts when it is greater than 1.5. For a fractal dimension of 1.5, the maximum temperature rise at a microcontact is independent of its size. The maximum temperature rise at the largest microcontact is expressed as a function of the friction coefficient, sliding speed, elastic and thermal properties, real and apparent contact areas, and fractal parameters. The closed-form solutions for the distribution density function of the temperature rise can be used to calculate the fraction of the real contact area of fast sliding surfaces subjected to temperature rises in any given range. The present theory is applied to boundary-lubricated and dry sliding contacts to determine the fractions of the real contact area where lubricant degradation and thermal surface failure may occur.

APA, Harvard, Vancouver, ISO, and other styles

16

Lotta, Antonio. "Contact metric manifolds with large automorphism group and (κ, µ)-spaces." Complex Manifolds 6, no. 1 (January 1, 2019): 294–302. http://dx.doi.org/10.1515/coma-2019-0015.

Full text

Abstract:

AbstractWe discuss the classifiation of simply connected, complete (κ, µ)-spaces from the point of view of homogeneous spaces. In particular, we exhibit new models of (κ, µ)-spaces having Boeckx invariant -1. Finally, we prove that the number ${{(n + 1)(n + 2)} \over 2}$ is the maximum dimension of the automorphism group of a contact metric manifold of dimension 2n +1, n ≥ 2, whose symmetric operator h has rank at least 3 at some point; if this dimension is attained, and the dimension of the manifold is not 7, it must be a (κ, µ)-space. The same conclusion holds also in dimension 7 provided the almost CR structure of the contact metric manifold under consideration is integrable.

APA, Harvard, Vancouver, ISO, and other styles

17

Kuball, Tim, Georg Jahn, and Claas Pollmanns. "Intergenerational Contact Experiences and Their Relation to Ageism as a Multidimensional Construct." Innovation in Aging 5, Supplement_1 (December 1, 2021): 179. http://dx.doi.org/10.1093/geroni/igab046.684.

Full text

Abstract:

Abstract Research on intergroup contact suggests that negative contact experiences affect cognitive representations such as stereotypes more strongly than positive contact experiences. To comprehensively examine the full effect of intergroup contact, the valence of the contact experience as well as the affective and cognitive dimensions of prejudice should be assessed. In ageism research, previous studies typically focused only on contact of positive valence and were limited to the perspectives of younger individuals on older adults. Primary objective of this study is to examine both positive and negative contact frequency and their relation to affective and cognitive dimensions of ageism from the perspectives of younger adults between the age of 18 and 25 (study 1) and older adults between the age of 60 and 92 (study 2). Consistent with previous research on intergroup contact, our results confirm that both types of contact were similarly predictive of affective facets of prejudice. However, only in study 2 that assessed older adults’ agreement with contemporary stereotypes about young men and women, negative compared to positive contact frequency proved to be a stronger predictor of the cognitive dimension of ageism. Our findings emphasize the importance of focusing on all dimensions of prejudice and highlight the need to consider the perspectives of young and old in ageism research.

APA, Harvard, Vancouver, ISO, and other styles

18

Kim, Jin Hong. "Examples of simply-connected K-contact non-Sasakian manifolds of dimension 5." International Journal of Geometric Methods in Modern Physics 12, no. 03 (February 27, 2015): 1550027. http://dx.doi.org/10.1142/s0219887815500279.

Full text

Abstract:

The existence of compact simply-connected K-contact, but not Sasakian, manifolds has been unknown only for dimension 5. The aim of this paper is to show that the Kollár's simply-connected example which is a Seifert bundle over the complex projective space ℂℙ2 and does not carry any Sasakian structure is actually a K-contact manifold. As a consequence, we affirmatively answer the above existence problem in dimension 5, establishing that there are infinitely many compact simply-connected K-contact manifolds of dimension 5 which do not carry a Sasakian structure.

APA, Harvard, Vancouver, ISO, and other styles

19

Liou, Jeng Luen, and Jen Fin Lin. "A New Method Developed for Fractal Dimension and Topothesy Varying With the Mean Separation of Two Contact Surfaces." Journal of Tribology 128, no. 3 (March 3, 2006): 515–24. http://dx.doi.org/10.1115/1.2197839.

Full text

Abstract:

Instead of a general consideration of the fractal dimension (D) and the topothesy (G*) as two invariants in the fractal analysis of surface asperities, these two roughness parameters in the present study are varied by changing the mean separation (d*) of two contact surfaces. The relationship between the fractal dimension and the mean separation is found first. By equating the structure functions developed in two different ways, the relationship among the scaling coefficient in the power spectrum function, the fractal dimension, and topothesy of asperity heights can be established. The variation of topothesy can be determined when the fractal dimension and the scaling coefficient have been obtained from the experimental results of the number of contact spots and the power spectrum function at different mean separations. A numerical scheme is developed in this study to determine the convergent values of fractal dimension and topothesy corresponding to a given mean separation. The theoretical results of the contact spot number predicted by the present model show good agreement with the reported experimental results. Both the fractal dimension and the topothesy are elevated by increasing the mean separation. Significant differences in the contact load or the total contact area are shown between the models of constant D and G* and variable D and G* as the mean separation is reduced to smaller values.

APA, Harvard, Vancouver, ISO, and other styles

20

Blair, David E. "On the Sign of the Curvature of a Contact Metric Manifold." Mathematics 7, no. 10 (September 24, 2019): 892. http://dx.doi.org/10.3390/math7100892.

Full text

Abstract:

In this expository article, we discuss the author’s conjecture that an associated metric for a given contact form on a contact manifold of dimension ≥5 must have some positive curvature. In dimension 3, the standard contact structure on the 3-torus admits a flat associated metric; we also discuss a local example, due to Krouglov, where there exists a neighborhood of negative curvature on a particular 3-dimensional contact metric manifold. In the last section, we review some results on contact metric manifolds with negative sectional curvature for sections containing the Reeb vector field.

APA, Harvard, Vancouver, ISO, and other styles

21

Olszak, Zbigniew. "Normal almost contact metric manifolds of dimension three." Annales Polonici Mathematici 47, no. 1 (1986): 41–50. http://dx.doi.org/10.4064/ap-47-1-41-50.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Drescher, Martina. "La dimension pragmatico-discursive du français en contact." Journal of Language Contact 7, no. 1 (March 31, 2014): 62–92. http://dx.doi.org/10.1163/19552629-00701004.

Full text

Abstract:

The aim of this paper is two-fold : First it argues for a stronger consideration of the pragmatic and discourse level in research on language contact. Secondly it contributes to the pragmatics of a specific regional variety of French, namely Cameroonian French. Starting with a picture of the complex linguistic landscape of this multilingual African country, the paper stresses the importance of the pragmatic and discourse level by raising some of the crucial theoretical and methodological issues that a broader, usage-based view on language contact has to cope with. First it suggests that pragmatic and discourse conventions may be influenced by the local contact languages and secondly it emphasizes that they may not be specific to a language, but be shared by a much larger and encompassing community of discourse. A case study of Cameroonian radio phone-ins where callers seek advice on medical issues points out some of these conventions. Here the participants establish a specific participation framework that avoids direct interaction between caller and expert while the host is set in as a mediator. This global mitigation technique then allows for quite direct realisations of the advice at a local level.

APA, Harvard, Vancouver, ISO, and other styles

23

Dimov, G., E. Ivanova-Dimova, and I. Düntsch. "On dimension andweight of a local contact algebra." Filomat 32, no. 15 (2018): 5481–500. http://dx.doi.org/10.2298/fil1815481d.

Full text

Abstract:

As proved in [16], there exists a duality ?t between the category HLC of locally compact Hausdorff spaces and continuous maps, and the category DHLC of complete local contact algebras and appropriate morphisms between them. In this paper, we introduce the notions of weight wa and of dimension dima of a local contact algebra, and we prove that if X is a locally compact Hausdorff space then w(X) = wa(?t(X)), and if, in addition, X is normal, then dim(X) = dima(?t(X)).

APA, Harvard, Vancouver, ISO, and other styles

24

MALEKZADEH, Nasrin, and Esmaiel ABEDI. "Semisymmetric contact metric manifolds of dimension $\geq 5$." TURKISH JOURNAL OF MATHEMATICS 42 (2018): 34–48. http://dx.doi.org/10.3906/mat-1612-107.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Bao, Erkao, and Ko Honda. "Definition of cylindrical contact homology in dimension three." Journal of Topology 11, no. 4 (September 6, 2018): 1002–53. http://dx.doi.org/10.1112/topo.12077.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Charbonneau, Georges. "La dimension de contact et les troubles esthéticophysiognomiques." L'Évolution Psychiatrique 71, no. 1 (January 2006): 57–73. http://dx.doi.org/10.1016/j.evopsy.2006.01.001.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Doubrov, Boris, Alexandr Medvedev, and Dennis The. "Homogeneous Integrable Legendrian Contact Structures in Dimension Five." Journal of Geometric Analysis 30, no. 4 (July 4, 2019): 3806–58. http://dx.doi.org/10.1007/s12220-019-00219-x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Fang, Gui Fang, Peng Gao Zhang, and Long Wei. "Effect of Surface Topography on Contact Property of the End Face for Mechanical Seal." Applied Mechanics and Materials 419 (October 2013): 292–98. http://dx.doi.org/10.4028/www.scientific.net/amm.419.292.

Full text

Abstract:

In order to understand the contact property of the end face for mechanical seal, simulation models of the elastic contact area ratio, the elastic-plastic contact area ration and the plastic contact area ratio of the end face are established using fractal parameters to characterize the surface topography. The effects of surface topography fractal parameters of B104a-70 mechanical seal on contact properties of the end faces are analyzed by theoretical simulation. The results show that the elastic contact area ratio increases rapidly at first and then decreases gradually, the elastic-plastic contact area ration decreases rapidly at first and then changes slightly, and the plastic contact area ratio changes slightly at first and then increases gradually with the increases of fractal dimension; the elastic contact area ratio decreases, and both the elastic-plastic contact area ratio and the plastic contact area ratio increase with the increases of the characteristic length scale; the proportion of the elastic contact area is larger, and the proportions of the elastic-plastic contact area and the plastic contact area are smaller when the end face is smooth; there exist an optimal value of fractal dimension between the faces of mechanical seal to make the elastic contact area ratio biggest, and the wear smallest. For B104a-70 mechanical seal, the optimal fractal dimension of the end face of the soft ring is about 1.63.

APA, Harvard, Vancouver, ISO, and other styles

29

Afferrante, L., M. Ciavarella, and G. Demelio. "Adhesive contact of the Weierstrass profile." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 471, no. 2182 (October 2015): 20150248. http://dx.doi.org/10.1098/rspa.2015.0248.

Full text

Abstract:

The Weierstrass series was considered in Ciavarella et al. (Ciavarella et al. 2000 Proc. R. Soc. Lond. A 456 , 387–405. ( doi:10.1098/rspa.2000.0522 )) to describe a linear contact problem between a rigid fractally rough surface and an elastic half-plane. In such cases, no applied mean pressure is sufficiently large to ensure full contact, and specifically there are not even any contact areas of finite dimension. Later, Gao & Bower (Gao & Bower 2006 Proc. R. Soc. A 462 , 319–348. ( doi:10.1098/rspa.2005.1563 )) introduced plasticity in the Weierstrass model, but concluded that the fractal limit continued to lead to what they considered unphysical predictions of the true contact size and number of contact spots, similar to the elastic case. In this paper, we deal with the contact problem between rough surfaces in the presence of adhesion with the assumption of a Johnson, Kendall and Roberts (JKR) regime. We find that, for fractal dimension D >1.5, the presence of adhesion does not qualitatively modify the contact behaviour. However, for fractal dimension D <1.5, a regularization of the contact area can be observed at a large magnification where the contact area consists of segments of finite size. Moreover, full contact can occur at all scales for D <1.5 provided the mean contact pressure is larger than a certain value. We discuss, however, the implication of our assumption of a JKR regime.

APA, Harvard, Vancouver, ISO, and other styles

30

Li, Xin, and Bingbing Wang. "An Adhesive Wear Model Based on a Complete Contact Model for a Fractal Surface." Journal of Physics: Conference Series 2095, no. 1 (November 1, 2021): 012098. http://dx.doi.org/10.1088/1742-6596/2095/1/012098.

Full text

Abstract:

Abstract An adhesive wear model based on a complete contact model for a fractal surface is presented in this work. A contact model which contains effect of adhesion is firstly presented based on ME model. A complete contact model is then proposed. Finally, an adhesive wear model based on this model is given. The results suggest that the maximum contact area increases firstly and then decreases as fractal dimension increases. The percentage of plastic contact area increases with increase of the fractal dimension. And the experimental results for wear volume have shown a good consistency with the results calculated by the wear model.

APA, Harvard, Vancouver, ISO, and other styles

31

Haas, Peter, Milan Kadnár, Juraj Rusnák, František Tóth, and Dušan Nógli. "Influence of RC Element Wiring in Electrical Circuit on Electromechanical Thermostat Contact Wear." Acta Technologica Agriculturae 19, no. 3 (September 1, 2016): 63–69. http://dx.doi.org/10.1515/ata-2016-0014.

Full text

Abstract:

Abstract Contact wear caused by electric arc during electric contact make (cut-in) and break (cut-out) has the direct impact on the contact lifetime. The RC element wired parallelly to the contact will eliminate or reduce the arcing and subsequently extend the lifetime. Comparative tests of the two sets of identical Danfoss 077B electromechanical thermostats have been carried out. In the first batch, standard thermostats were tested. In the second batch, the same thermostat types, but with RC elements wired parallel to thermostats main contacts were tested. Measurement has not proven any improvement of the contact wear. Temperature drift and change of the critical dimension caused by contact wear were very similar in the both cases. Thus, the application of RC element is considered not reasonable measure for reduction of contact wear of electromechanical thermostats.

APA, Harvard, Vancouver, ISO, and other styles

32

Vasko, Anthony, Kristopher Wieland, and Victor Karpov. "Point Contact Admittance Spectroscopy of Thin Film Solar Cells." MRS Proceedings 1538 (2013): 227–33. http://dx.doi.org/10.1557/opl.2013.1012.

Full text

Abstract:

ABSTRACTWe present the new characterization technique of multi-dimensional admittance measurements. In standard admittance measurements, a semiconductor device is probed in the transverse dimension, between flat plate contacts. We extend such measurements to distributed, possibly non-uniform solar cells where one of the two contacts has very small (point-like) dimensions. As a result, both the real and displacement currents spread into lateral directions while flowing between the electrodes. Correspondingly, the probing electric field may result in contact voltages that are laterally not equipotential. The spatial voltage distribution will depend on the probing DC bias and AC frequency. The resulting measurement will give information about the system’s lump parameters, such as open circuit voltage, sheet and shunt resistances, as well as the presence and location of shunts. Understanding of the measurement is developed through intuitive and analytic models. Numerical models, utilizing finite element circuits, are used to verify the analytic results, and also may be directly compared to or used to fit experimental data. While our focus is on introducing the physical theory, early experimental results demonstrating spatial scaling are shown.

APA, Harvard, Vancouver, ISO, and other styles

33

Ostromęcka, Małgorzata, and Andrzej Aniszewicz. "Influence of the Applied Measurement Methodology on the Results of Geometric Measurements of the SB4 Spring Clips." Problemy Kolejnictwa - Railway Reports 65, no. 191 (June 2021): 89–93. http://dx.doi.org/10.36137/1914e.

Full text

Abstract:

The article presents the results of measurements of the “b” dimension of the SB4 spring clips carried out using three measurement methods that differ in the method and width of the base plate contact. The results obtained are presented and the uncertainty of measurement for each method is estimated. Attention was paid to the issues of the obtained dispersion of the value of the “b” dimension. The tolerated dimensions are discussed. The proposed measurement methods can help to identify shape mismatches of spring clips. Keywords: rail fastening, spring clip, dimensional measurements, clamping force

APA, Harvard, Vancouver, ISO, and other styles

34

Jourani, Abdeljalil. "Effect of 3D fractal dimension on contact area and asperity interactions in elastoplastic contact." AIP Advances 6, no. 5 (May 2016): 055309. http://dx.doi.org/10.1063/1.4949564.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Loiudice, Eugenia. "A dimensional restriction for a class of contact manifolds." Demonstratio Mathematica 50, no. 1 (September 26, 2017): 231–38. http://dx.doi.org/10.1515/dema-2017-0021.

Full text

Abstract:

Abstract In this work we consider a class of contact manifolds (M, η) with an associated almost contact metric Structure (ϕ, ξ, η, g). This class contains, for example, nearly cosymplectic manifolds and the manifolds in the class C9 ⊕ C10 defined by Chinea and Gonzalez. All manifolds in the class considered turn out to have dimension 4n + 1. Under the assumption that the sectional curvature of the horizontal 2-planes is constant at one point, we obtain that these manifolds must have dimension 5.

APA, Harvard, Vancouver, ISO, and other styles

36

Raman, S., and J. Chellaperumal. "Re-examining the machining frictional boundary conditions using fractals." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 216, no. 7 (July 1, 2002): 993–97. http://dx.doi.org/10.1243/09544050260174193.

Full text

Abstract:

This paper presents experimental evidence for the existence of non-Euclidean contact geometry at the tool-chip interface in the machining of aluminium alloy, which challenges conventional assumptions. The geometry of contact at the tool rake face is modelled using fractals and a dimension is computed for its description. The variation in the fractal dimension with the cutting speed is explored.

APA, Harvard, Vancouver, ISO, and other styles

37

CHO, YONG SEUNG. "QUANTUM TYPE COHOMOLOGIES ON CONTACT MANIFOLDS." International Journal of Geometric Methods in Modern Physics 10, no. 05 (April 3, 2013): 1350012. http://dx.doi.org/10.1142/s0219887813500126.

Full text

Abstract:

We extend the notion of a pseudoholomorphic map in a symplectic manifold to the one of an almost coholomorphic map on a contact manifold M of an odd dimension. We study the moduli space of stable almost coholomorphic maps that represent a two-dimensional integral homology class of M, Gromov–Witten type invariants, quantum type products and quantum type cohomologies.

APA, Harvard, Vancouver, ISO, and other styles

38

Foreman, Brendan J. "K-contact Lie groups of dimension five or greater." Kodai Mathematical Journal 34, no. 1 (March 2011): 79–84. http://dx.doi.org/10.2996/kmj/1301576763.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Hadjar, Amine. "Sur Les Structures De Contact Regulieres En Dimension Trois." Transactions of the American Mathematical Society 347, no. 7 (July 1995): 2473. http://dx.doi.org/10.2307/2154832.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Colin, Vincent. "Stabilit� topologique des structures de contact en dimension 3." Duke Mathematical Journal 99, no. 2 (August 1999): 329–51. http://dx.doi.org/10.1215/s0012-7094-99-09912-x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Hadjar, Amine. "Sur les structures de contact régulières en dimension trois." Transactions of the American Mathematical Society 347, no. 7 (July 1, 1995): 2473–80. http://dx.doi.org/10.1090/s0002-9947-1995-1308013-5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Abbondandolo, Alberto, Barney Bramham, Umberto L. Hryniewicz, and Pedro A. S. Salomão. "Contact forms with large systolic ratio in dimension three." ANNALI SCUOLA NORMALE SUPERIORE - CLASSE DI SCIENZE 19, no. 4 (2019): 1561–82. http://dx.doi.org/10.2422/2036-2145.201709_005.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Tyapin, N. A. "Affine contact manifolds with automorphism group of maximal dimension." Mathematical Notes 91, no. 3-4 (April 2012): 453–56. http://dx.doi.org/10.1134/s0001434612030182.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Dacal, Luis C. O., and Erasmo A. de Andrada e. Silva. "Contact Dimension Effects in the Conductance of Semiconductor Nanowires." Journal of Superconductivity 18, no. 3 (September 2, 2005): 375–77. http://dx.doi.org/10.1007/s10948-005-0013-2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Rukimbira, Philippe. "The dimension of leaf closures of K-contact flows." Annals of Global Analysis and Geometry 12, no. 1 (February 1994): 103–8. http://dx.doi.org/10.1007/bf02108291.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Boyer, Charles P., Leonardo Macarini, and Otto van Koert. "Brieskorn manifolds, positive Sasakian geometry, and contact topology." Forum Mathematicum 28, no. 5 (September 1, 2016): 943–65. http://dx.doi.org/10.1515/forum-2015-0142.

Full text

Abstract:

AbstractUsing ${S^{1}}$-equivariant symplectic homology, in particular its mean Euler characteristic, of the natural filling of links of Brieskorn–Pham polynomials, we prove the existence of infinitely many inequivalent contact structures on various manifolds, including in dimension 5 the k-fold connected sums of ${S^{2}\times S^{3}}$ and certain rational homology spheres. We then apply our result to show that on these manifolds the moduli space of classes of positive Sasakian structures has infinitely many components. We also apply our results to give lower bounds on the number of components of the moduli space of Sasaki–Einstein metrics on certain homotopy spheres. Finally, a new family of Sasaki–Einstein metrics of real dimension 20 on ${S^{5}}$ is exhibited.

APA, Harvard, Vancouver, ISO, and other styles

47

Luen Liou, Jeng, and Jen Fin Lin. "A New Microcontact Model Developed for Variable Fractal Dimension, Topothesy, Density of Asperity, and Probability Density Function of Asperity Heights." Journal of Applied Mechanics 74, no. 4 (April 19, 2006): 603–13. http://dx.doi.org/10.1115/1.2338059.

Full text

Abstract:

In the present study, the fractal theory is applied to modify the conventional model (the Greenwood and Williamson model) established in the statistical form for the microcontacts of two contact surfaces. The mean radius of curvature (R) and the density of asperities (η) are no longer taken as constants, but taken as variables as functions of the related parameters including the fractal dimension (D), the topothesy (G), and the mean separation of two contact surfaces. The fractal dimension and the topothesy varied by differing the mean separation of two contact surfaces are completely obtained from the theoretical model. Then the mean radius of curvature and the density of asperities are also varied by differing the mean separation. A numerical scheme is thus developed to determine the convergent values of the fractal dimension and topothesy corresponding to a given mean separation. The topographies of a surface obtained from the theoretical prediction of different separations show the probability density function of asperity heights to be no longer the Gaussian distribution. Both the fractal dimension and the topothesy are elevated by increasing the mean separation. The density of asperities is reduced by decreasing the mean separation. The contact load and the total contact area results predicted by variable D, G*, and η as well as non-Gaussian distribution are always higher than those forecast with constant D, G*, η, and Gaussian distribution.

APA, Harvard, Vancouver, ISO, and other styles

48

Monaci, Maria Grazia. "Interethnic workplace conflict: Reciprocal perception of Italian and immigrant blue-collar coworkers." Europe’s Journal of Psychology 18, no. 2 (May 31, 2022): 193–206. http://dx.doi.org/10.5964/ejop.2395.

Full text

Abstract:

Past research has examined the beneficial effects of contact focusing mainly on the affective dimension of intergroup relationships. Limited research has examined cognitive dimensions, in particular considering at the same time minority and majority group perspectives. This study tested whether contact in a work context relates differentially to the perception of interethnic conflict in Italian (n = 67) and immigrant (n = 40, all male) blue-collar coworkers with the potential mediation of reciprocal stereotypical content (competence and warmth dimensions), interethnic attitudes, perceived discrimination, and whether organizational identification amplifies the effect of contact. Multigroup path analysis revealed that the two stereotype dimensions, warmth and competence, mediate the relationship between interethnic contact and perceived discrimination for Italians, and between organizational identification and perceived conflict for immigrants. Results highlighted an asymmetrical effect of contact on perceived conflict, detrimental and direct for immigrant workers, beneficial and mediate via the outgroup cognitive image for the Italian workers. Findings suggest that a superordinate identity, in terms of organizational identification, may be effective in reducing conflict at the workplace for majority members, whilst a personalized strategy seems to be more suitable for minority members. The theoretical and practical implications of these findings are discussed along with the acculturation perspective.

APA, Harvard, Vancouver, ISO, and other styles

49

Sweeney, Grace M., Keith A. Nichols, and Paul Kline. "Job Stress in Occupational Therapy: An Examination of Causative Factors." British Journal of Occupational Therapy 56, no. 3 (March 1993): 89–93. http://dx.doi.org/10.1177/030802269305600304.

Full text

Abstract:

This article, the first in a series of two on job stress in occupational therapy, reports the results of a postal survey which set out to identify factors that contributed to stress in a sample of Britain-based occupational therapists. Three hundred and ten NHS and LASS occupational therapists were surveyed between November 1989 and February 1990. The results indicated that four different dimensions of job stress were relevant to occupational therapists, and these were labelled ‘professional value’, ‘resources and demands’, ‘rewards and recognition’ and ‘patient contact’. Further analysis indicated that occupational therapists who worked longer hours, who had been in the job for a longer period of time, and who were employed in social services tended to score higher on the dimension of rewards and recognition. Employment at the level of basic grade, senior II or senior i tended to be predictive of a high score on the dimension of stress related to patient contact. Occupational therapists who had been qualified for longer periods of time tended to score lower on both these dimensions of job stress. This article explores possible explanations for these differences, and the second article will propose individual and organisational strategies for stress reduction.

APA, Harvard, Vancouver, ISO, and other styles

50

Noda, Nao-Aki, Masato Nagawa, Fumitaka Shiraishi, and Akifumi Inoue. "Sealing Performance of New Gasketless Flange." Journal of Pressure Vessel Technology 124, no. 2 (May 1, 2002): 239–46. http://dx.doi.org/10.1115/1.1464876.

Full text

Abstract:

This paper deals with a new seal system between two flanges without using gaskets. The system includes a groove and an annular lip that is held by one of the flange with its highest point in contact with the other flange to form a seal line when the flanges are assembled. The condition whether the system leaks or not depends on the shape and dimension of the annular lip and its deformation during the contact. In this study, several gasketless flanges are prepared with different lip dimensions to investigate the contact and sealing condition through an experimental and FEM analyses. The analyses indicate that the conditions can be expressed in terms of the maximum contact stress and the plastic zone size when the flanges are assembled. The helium leak testing reveals that the gasketless flange has better sealing performance compared to conventional gaskets.

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!