Results 81 to 90 of about 147,831 (333)

Unrolling of Syngonium podophyllum: Functional Anatomy, Morphology and Modelling of Its Peltate Leaves

Advanced Biology, EarlyView.
The unrolling of the peltate leaves in Syngonium podophyllum is analyzed and quantified (left‐hand side to center). These measurements serve to verify a mathematical model for leaf unrolling based on the model used in Schmidt (2007). An additional formula for obtaining a layer mismatch from a prescribed radius is derived.
Michelle Modert, Nick Seinsche, Sören Bartels, Tom Masselter, Thomas Speck   +4 more
wiley   +1 more source

A Planarity Criterion for Graphs [PDF]

SIAM Journal on Discrete Mathematics, 2015
It is proven that a connected graph is planar if and only if all its cocycles with at least four edges are "grounded" in the graph. The notion of grounding of this planarity criterion, which is purely combinatorial, stems from the intuitive idea that with planarity there should be a linear ordering of the edges of a cocycle such that in the two ...
Kosta Došen, Zoran Petric
openaire   +3 more sources

Soft‐Layered Composites with Wrinkling‐Activated Multi‐Linear Elastic Behavior, Stress Mitigation, and Enhanced Strain Energy Storage

Advanced Engineering Materials, EarlyView.
In this study, exciting new bi‐/multi‐linear elastic behavior of soft elastic composites that accompany the activation of wrinkling in the embedded interfacial layers is analyzed. The new features and performance of these composite materials, including dramatic enhancements in energy storage, can be tailored by the concentration of interfacial layers ...
Narges Kaynia, Nicholas Xuanlai Fang, Mary C. Boyce   +2 more
wiley   +1 more source

On the Complexity of Planar Covering of Small Graphs

, 2011
The problem Cover(H) asks whether an input graph G covers a fixed graph H (i.e., whether there exists a homomorphism G to H which locally preserves the structure of the graphs). Complexity of this problem has been intensively studied.
Bílka, Ondřej, Jirásek, Jozef, Klavík, Pavel, Tancer, Martin, Volec, Jan   +4 more
core   +1 more source

Mechanochemical Synthesis and Characterization of Nanostructured ErB4 and NdB4 Rare‐Earth Tetraborides

Advanced Engineering Materials, Volume 27, Issue 6, March 2025.
ErB4 and NdB4 nanostructured powders are produced by mechanochemical synthesis. 5 h mechanical alloying and 4 M HCl acid leaching are used in the production. ErB4 and NdB4 powders exhibit maximum magnetization of 0.4726 emu g−1 accompanied with an antiferromagnetic‐to‐paramagnetic phase transition at about TN = 18 K and 0.132 emu g−1 with a maximum at ...
Burçak Boztemur, Faruk Kaya, Bora Derin, Mustafa Lütfi Öveçoğlu, Ju Li, Duygu Ağaoğulları   +5 more
wiley   +1 more source

Planar graphs with $\Delta \geq 7$ and no triangle adjacent to a $C_4$ are minimally edge and total choosable [PDF]

Discrete Mathematics & Theoretical Computer Science, 2016
For planar graphs, we consider the problems of list edge coloring and list total coloring. Edge coloring is the problem of coloring the edges while ensuring that two edges that are adjacent receive different colors.
Marthe Bonamy, Benjamin Lévêque, Alexandre Pinlou   +2 more
doaj   +1 more source

Recognizing and Drawing IC-planar Graphs

, 2015
IC-planar graphs are those graphs that admit a drawing where no two crossed edges share an end-vertex and each edge is crossed at most once. They are a proper subfamily of the 1-planar graphs.
C Auer, C Auer, C Binucci, C Thomassen, D Král, E Ackerman, E Giacomo Di, E Giacomo Di, E Giacomo Di, EN Argyriou, FJ Brandenburg, H Fraysseix de, J Fox, J Pach, M Chrobak, MA Bekos, MJ Alam, MR Garey, O Cheong, OV Borodin, P Eades, S Hong, S-H Hong, VP Korzhik, W Didimo, W Didimo, X Zhang, X Zhang   +27 more
core   +1 more source

Comparative Wear and Friction Analysis of Sliding Surface Materials for Hydrostatic Bearing under Oil Supply Failure Conditions

Advanced Engineering Materials, EarlyView.
Hydrostatic bearings excel in high‐precision applications, but their performance hinges on a continuous external supply. This study evaluates various material combinations for sliding surfaces to mitigate damage during supply failures or misalignment and to discover the most effective materials identified for enhancing the reliability and efficiency of
Michal Michalec, Lukáš Daněk, Jan Foltýn, Petr Svoboda, Carsten Gachot, Martin Hartl, Ivan Křupka   +6 more
wiley   +1 more source

Subdivisions in Planar Graphs

Journal of Combinatorial Theory, Series B, 1998
Given four distinct vertices in a 4-connected planar graph \(G\), we characterize when the graph \(G\) contains a \(K_4\)-subdivision with the given vertices as its degree three vertices. This result implies the following conjecture of Robertson and Thomas: a 5-connected planar graph has no \(K_4\)-subdivision with specified degree three vertices, if ...
openaire   +2 more sources

Planar Transitive Graphs [PDF]

The Electronic Journal of Combinatorics, 2018
We prove that the first homology group of every planar locally finite transitive graph $G$ is finitely generated as an $\Aut(G)$-module and we prove a similar result for the fundamental group of locally finite planar Cayley graphs. Corollaries of these results include Droms's theorem that planar groups are finitely presented and Dunwoody's theorem that
openaire   +3 more sources