Results 71 to 80 of about 192 (184)

Compact Manifolds With Unbounded Nilpotent Fundamental Groups and Positive Ricci Curvature

Communications on Pure and Applied Mathematics, EarlyView.
ABSTRACT It follows from the work of Kapovitch and Wilking that a closed manifold with nonnegative Ricci curvature has a uniformly almost nilpotent fundamental group. Leftover questions and conjectures, have asked if in this context the fundamental group is actually uniformly almost abelian. The main goal of this work is to construct examples (Mk9,gk)$(
Elia Bruè, Aaron Naber, Daniele Semola
wiley   +1 more source

Simplified Small‐Signal Modeling Method for Non‐Isolated High Step‐Up Converters

International Journal of Circuit Theory and Applications, EarlyView.
A generalized small‐signal modeling methodology for a family of non‐isolated high step‐up DC‐DC converters is proposed. ABSTRACT This work presents a generalized small‐signal modeling methodology for a family of DC–DC converters based on the four‐state switching cell with a wide conversion range (WCR‐4SSC) operating in continuous conduction mode (CCM).
Samuel Antonio Macedo de Oliveira, Pedro Herysson Almeida da Silva, Fernando Lessa Tofoli, Dalton de Araújo Honório   +3 more
wiley   +1 more source

Photometric Diagnostic of the Sheath Dynamics and Electron Density Trends in Single and Dual Frequency CCRF Argon Plasmas

Contributions to Plasma Physics, EarlyView.
ABSTRACT A methodological study is presented on a noninvasive photometric diagnostic for determining trends in electron density and sheath dynamics in single (1f) and a dual (2f) radio frequency capacitively coupled (CCRF) argon plasmas. The 1f discharges are operated at 13.56 and 27.12 MHz, respectively, while the 2f discharge is driven by both ...
Daniel Zuhayra, Jessica Niemann, Viktor Schneider, Holger Kersten   +3 more
wiley   +1 more source

Review and prospects of shear test of bolted rock joints

Deep Underground Science and Engineering, EarlyView.
The laboratory shear test equipment, test method, and numerical simulation of bolted rock joints were summarized. The shortcomings and limitations of the current research were analyzed, and the research prospects were proposed. Abstract Rock bolting is a critical approach in geotechnical engineering for supporting weak rocks.
Shulin Ren, Fan Yang, Manchao He, Yong Yuan, Zhigang Tao   +4 more
wiley   +1 more source

Machine Learning Unveils Isolated‐Surrounded Pt Motifs in High‐Entropy Alloys for Superior Low‐Temperature Ammonia Oxidation

ENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
A physics‐informed machine learning approach successfully decodes the complex catalytic activity of high‐entropy alloys for ammonia oxidation. By revealing a synergistic mechanism involving lattice and electronic couplings, the study identifies a superior “isolated‐surrounded” platinum motif.
Shangfeng Jiang, Ting Tao, Kexiang Guo, Xinyu Fan, Xu Zhang, Zhen Zhou   +5 more
wiley   +1 more source

How Multiple Streams Influence Agenda‐Setting for Water Reuse in Swiss Substates

Environmental Policy and Governance, EarlyView.
ABSTRACT As climate change creates significant challenges for both the environment and society, potential mitigation and adaptation solutions are widely discussed. Yet, neither challenges nor their potential solutions automatically reach the political agenda or lead to a policy decision.
Magdalena A. Knabl, Katrin Pakizer, Manuel Fischer, Eberhard Morgenroth, Christian Binz   +4 more
wiley   +1 more source

Influence of Structural and Environmental Parameters on Solar Air Collector Performance

Energy Science &Engineering, EarlyView.
Increasing air gap depth and mass flow rate significantly enhances the thermal performance of solar air collectors, with optimal performance achieved at an 8.5 cm air gap and 0.01318 kg/s mass flow rate. Air gap depth is identified as the dominant factor influencing system efficiency.
Quankun Zhu, István Farkas, János Buzas   +2 more
wiley   +1 more source

Edge‐Based Discretizations on Triangulations in Any Dimension, With Special Attention to Four‐Dimensional Space

International Journal for Numerical Methods in Fluids, EarlyView.
This article provides important geometric formulas for node‐centered, edge‐based schemes in any number of dimensions. These formulas are noteworthy, as they do not require the explicit formation of dual regions. We prove several key geometric results, with a particular focus on the four‐dimensional case, due to potential space‐time applications ...
Nicholas Tufillaro, David M. Williams, Hiroaki Nishikawa   +2 more
wiley   +1 more source

Subspace Acceleration for Efficient Nonlinear Water Wave Simulation

International Journal for Numerical Methods in Fluids, EarlyView.
We introduce an exponentially weighted subspace acceleration technique to reduce GMRES iterations for solving the Poisson equation with time‐dependent coefficients in nonlinear, dispersive free‐surface flows governed by the incompressible Navier‐Stokes equations. The method significantly reduces memory requirements and computational complexity compared
Rasmus Kleist Hørlyck Sørensen, Margherita Guido, Allan Peter Engsig‐Karup, Daniel Kressner   +3 more
wiley   +1 more source

Quadratic systems with an invariant algebraic curve of degree 3 and a Darboux invariant

Electronic Journal of Differential Equations, 2021
Jaume Llibre, Regilene D. S. Oliveira, Camila A. B. Rodrigues   +2 more
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