Az online világ új hatalmasai

2014 ◽  
Vol 14 (4) ◽  
pp. 139
Author(s):  
Lilla Hargitai
Keyword(s):  
Screen Distribution

Stuart Cunningham – Jon Silver: Screen Distribution and the New King Kongs of the Online World (Palgrave Macmillan, 2013) című könyvéről

scholarly journals On Co-screen Conformality of 1-lightlike Submanifolds in a Lorentzian Manifold

2015 ◽  
Vol 7 (2) ◽  
pp. 76
Author(s):  
Erol Kilic ◽  
Sadik Keles ◽  
Mehmet Gulbahar
Keyword(s):  
Ricci Tensor ◽  
Lorentzian Manifold ◽  
Conformal Killing ◽  
Screen Distribution ◽  
Locally Conformal ◽  
Lightlike Submanifolds

In this paper, the co-screen conformal 1-lightlike submanifolds of a Lorentzian manifoldare introduced as a generalization of co-screen locally half-lightlike submanifolds in(Wang,  Wang {\&} Liu, 2013; Wang {\&} Liu, 2013) and two examples are given whichone is co-screen locally conformal andthe other is not. Some results are obtained on these submanifolds whichthe co-screen distribution is conformal Killing on the ambient manifold.The induced Ricci tensor of  co-screen conformal 1-lightlike submanifolds isinvestigated.

Research on Performance of Foundry Sand under the Effect of Chemical Binder

2014 ◽  
Vol 597 ◽  
pp. 262-265
Author(s):  
Qing Zhou Sun ◽  
Jing Guang Yan ◽  
Pu Qing Zhang ◽  
Zhong Kui Zhao ◽  
Hang Du
Keyword(s):  
Particle Size ◽  
Tensile Strength ◽  
Phenolic Resin ◽  
Grain Shape ◽  
Clay Content ◽  
Molding Sand ◽  
Foundry Sand ◽  
Screen Distribution ◽  
Resin Adhesive ◽  
Different Origin

This paper makes an experiental research on the performance of foundry sand under the effect of chemical binder. It discoveries the raw sand with different origin will have different properties even though they have the same particle size. The properties of their molding sand are also obviously different. For the raw sand that in the same particle size with similar acid demand value and four-screen distribution, the better grain shape will earn them a higher molding sand strength even though they have higher clay content. Under the effect of liquid binder, compared to the molding sand mixed from the sand of three-screen distribution, the molding sand mixed from those of four-screen distribution sand with other properties similar will have a higher tensile strength While under the effect of solid phenolic resin adhesive, the three-screen sand with good grain shape will have a high sand strength.

scholarly journals Screen conformal half-lightlike submanifolds

2004 ◽  
Vol 2004 (68) ◽  
pp. 3737-3753 ◽  
Author(s):  
K. L. Duggal ◽  
B. Sahin
Keyword(s):  
Riemannian Manifold ◽  
Sectional Curvature ◽  
Ricci Tensor ◽  
Shape Operator ◽  
Close Relation ◽  
Screen Distribution ◽  
Lightlike Submanifolds ◽  
Half Lightlike Submanifold ◽  
Lightlike Submanifold

We study some properties of a half-lightlike submanifoldM, of a semi-Riemannian manifold, whose shape operator is conformal to the shape operator of its screen distribution. We show that any screen distributionS(TM)ofMis integrable and the geometry ofMhas a close relation with the nondegenerate geometry of a leaf ofS(TM). We prove some results on symmetric induced Ricci tensor and null sectional curvature of this class.

scholarly journals Some properties of lightlike submanifolds of semi-Riemannian manifolds

2010 ◽  
Vol 43 (3) ◽  
Author(s):  
Rakesh Kumar ◽  
Rachna Rani ◽  
R. K. Nagaich
Keyword(s):  
Riemannian Manifolds ◽  
Sufficient Condition ◽  
Necessary And Sufficient Condition ◽  
Totally Geodesic ◽  
Screen Distribution ◽  
Necessary And Sufficient ◽  
Lightlike Submanifolds ◽  
Lightlike Submanifold

AbstractWe initially obtain various relations and then establish necessary and sufficient condition for the integrability of screen distribution of a lightlike submanifold. We also establish necessary and sufficient condition for a lightlike submanifold to be totally geodesic.

Radical screen transversal lightlike submanifolds of indefinite Kaehler manifolds admitting a quarter-symmetric non-metric connection

2018 ◽  
Vol 15 (02) ◽  
pp. 1850024
Author(s):  
Garima Gupta ◽  
Rakesh Kumar ◽  
Rakesh Kumar Nagaich
Keyword(s):  
Product Manifold ◽  
Necessary And Sufficient Condition ◽  
Kaehler Manifold ◽  
Screen Distribution ◽  
Kaehler Manifolds ◽  
Metric Connection ◽  
Necessary And Sufficient ◽  
Characterization Theorems ◽  
Lightlike Submanifolds ◽  
Lightlike Submanifold

We study radical screen transversal ([Formula: see text])-lightlike submanifolds of an indefinite Kaehler manifold admitting a quarter-symmetric non-metric connection and obtain a necessary and sufficient condition for the screen distribution of a radical [Formula: see text]-lightlike submanifold to be integrable. We also study totally umbilical radical [Formula: see text]-lightlike submanifolds and obtain some characterization theorems for a radical [Formula: see text]-lightlike submanifold to be a lightlike product manifold. Finally, we establish some results regarding the vanishes of null sectional curvature.

Touch screen distribution deal

Displays ◽  
1986 ◽  
Vol 7 (1) ◽  
pp. 45
Author(s):  
Ellinor Peripherals Ltd
Keyword(s):  
Touch Screen ◽  
Screen Distribution

scholarly journals A characterization of minimal ascreen null hypersurfaces of $(LCS)$-space forms

2019 ◽  
Author(s):  
Samuel Ssekajja
Keyword(s):  
Constant Curvature ◽  
Ricci Tensor ◽  
Space Form ◽  
Null Hypersurface ◽  
Space Forms ◽  
Screen Distribution ◽  
Null Hypersurfaces ◽  
Null Curve

In the present paper, we study nontotally geodesic minimal ascreen null hypersurface, $M$, of a Lorentzian concircular structure $(LCS)$-space form of constant curvature $0$ or $1$. We prove that; if the Ricci tensor of $M$ is parallel with respect to any leaf of its screen distribution, then $M$ is isometric to a product of a null curve and spheres.

scholarly journals Co-screen conformal half-lightlike submanifolds

2013 ◽  
Vol 44 (4) ◽  
pp. 431-444
Author(s):  
Yaning Wang ◽  
Ximin Liu
Keyword(s):  
Riemannian Manifold ◽  
Curvature Tensor ◽  
Sufficient Conditions ◽  
Shape Operator ◽  
Geometric Condition ◽  
Screen Distribution ◽  
Unique Existence ◽  
Lightlike Submanifolds ◽  
Half Lightlike Submanifold ◽  
Lightlike Submanifold

In this paper, we introduce and study the geometry of half lightlike submanifold $M$ of a semi-Riemannian manifold $\overline{M}$ satisfying that the shape operator of screen transversal bundle is conformal to the shape operator of lightlike transversal bundle of $M$. Using this geometric condition we obtain some results to characterize the unique existence of screen distribution of $M$, also, we present some sufficient conditions for the induced Ricci curvature tensor of $M$ to be symmetric.

Einstein-Weyl structures on lightlike hypersurfaces

2013 ◽  
Vol 11 (10) ◽  
Author(s):  
Cyriaque Atindogbe ◽  
Lionel Bérard-Bergery ◽  
Carlos Ogouyandjou
Keyword(s):  
Conformal Structure ◽  
Geometric Properties ◽  
Lorentzian Space ◽  
Totally Umbilical ◽  
Screen Distribution ◽  
Lightlike Hypersurfaces

AbstractWe study Weyl structures on lightlike hypersurfaces endowed with a conformal structure of certain type and specific screen distribution: the Weyl screen structures. We investigate various differential geometric properties of Einstein-Weyl screen structures on lightlike hypersurfaces and show that, for ambient Lorentzian space ℝ1n+2 and a totally umbilical screen foliation, there is a strong interplay with the induced (Riemannian) Weyl-structure on the leaves.

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