Results 91 to 100 of about 37,802 (311)

A new twist on the geometry of gravitational plane waves

Journal of High Energy Physics, 2017
The geometry of twisted null geodesic congruences in gravitational plane wave spacetimes is explored, with special focus on homogeneous plane waves.
Graham M. Shore
doaj   +1 more source

Rigid motion revisited: rigid quasilocal frames

, 2008
We introduce the notion of a rigid quasilocal frame (RQF) as a geometrically natural way to define a "system" in general relativity. An RQF is defined as a two-parameter family of timelike worldlines comprising the worldtube boundary of the history of a ...
Bel Ll, Eriksen E, Griffiths D J, Landau L D, Llosa J, Llosa J Soler D, Misner C W, Nakahara M, Norton J, Paul L McGrath, Richard J Epp, Robert B Mann, Stachel J   +12 more
core   +1 more source

Effect of Regiochemistry on Doping and Thermoelectric Properties of n‐Doped Fullerene Derivatives

Advanced Electronic Materials, EarlyView.
Three fullerene derivatives doubly substituted with diethylene glycol chains (PDEG‐2) is presented. The different regiochemistry significantly affects the crystallinity and consequently the dielectric properties, electronic transport, and doping efficiency. By striking a balance between compatibility with the molecular dopant N‐DMBI and crystallinity a
Federico Ferrari, Sylvia Rousseva, Diego Rosas Villalva, Ewout Kessels, Jan C. Hummelen, Derya Baran, Ryan Chiechi, L. Jan Anton Koster   +7 more
wiley   +1 more source

Discrete constant mean curvature nets in space forms: Steiner's formula and Christoffel duality

, 2014
We show that the discrete principal nets in quadrics of constant curvature that have constant mixed area mean curvature can be characterized by the existence of a K\"onigs dual in a concentric quadric.Comment: 12 pages, 10 figures, pdfLaTeX (plain pdfTeX
Bobenko, A., Hertrich-Jeromin, U., Lukyanenko, I.   +2 more
core   +2 more sources

Correlations Between Osteocyte Lacuno‐Canalicular Network and Material Characteristics in Healthy and Mechanically Stimulated Murine Tibiae

Advanced NanoBiomed Research, EarlyView.
This article reveals how calcium content, mineral nanostructure, and lacuno‐canalicular network (LCN) organization interact to shape bone heterogeneity in mouse tibiae. Advanced multimodal imaging uncovers that mechanical loading promotes mature mineral structures even in low‐calcium regions, highlighting LCN‐driven mineralization and offering new ...
Victoria Schemenz, Maximilian Rummler, Alexander van Tol, Isabela Vitienes, Tobias Thiele, Markus A. Hartmann, Manfred Burghammer, Peter Fratzl, Richard Weinkamer, Bettina M. Willie, Wolfgang Wagermaier   +10 more
wiley   +1 more source

The Levi-Civita connections of Lorentzian manifolds with prescribed optical geometries

Cubo
We explicitly derive the Christoffel symbols in terms of adapted frame fields for the Levi-Civita connection of a Lorentzian \(n\)-manifold \((M, g)\), equipped with a prescribed optical geometry of Kähler-Sasaki type.
Dmitri V. Alekseevsky, Masoud Ganji, Gerd Schmalz, Andrea Spiro   +3 more
doaj   +1 more source

Accelerated FEM Analysis for Critical Engine Components

Walailak Journal of Science and Technology, 2014
This paper introduces a method to simplify a nonlinear problem in order to use linear finite element analysis. This approach improves calculation time by 2 orders of magnitude.
Leonardo FRIZZIERO, Luca PIANCASTELLI
doaj   +1 more source

On the dimension of polynomial semirings [PDF]

, 2015
In our previous work, motivated by the study of tropical polynomials, a definition for prime congruences was given for an arbitrary commutative semiring.
Joó, Dániel, Mincheva, Kalina
core   +1 more source

A comparative analysis of congruent triangle units in textbooks from China and the United States

Asian Journal for Mathematics Education
In this article, we report findings from a comparative study of the introduction and development of triangle congruence in two textbooks: a high school geometry textbook from the United States and an eighth-grade mathematics textbook from China.
Jane-Jane Lo, Lili Zhou, Jinqing Liu
doaj   +1 more source

Research about the number of D-points of -tiling in given ellipse

Journal of Hebei University of Science and Technology, 2017
An Archimedean tiling is a tiling of the plane by one type of regular polygon or several types of regular polygons, and every vertex of the tiling has the same vertex characteristics.
Xianglin WEI, Weiqi WANG
doaj   +1 more source