Results 131 to 140 of about 1,372,703 (368)

Cosmological Term, Mass, and Space-Time Symmetry [PDF]

open access: yes, 2004
In the spherically symmetric case the requirements of regularity of density and pressures and finiteness of the ADM mass $m$, together with the weak energy condition, define the family of asymptotically flat globally regular solutions to the Einstein minimally coupled equations which includes the class of metrics asymptotically de Sitter as $r\to 0$. A
openaire   +3 more sources

Combining Metal Additive Manufacturing and Casting Technology: High Performance Cooling Channels for Electric Powertrain Components

open access: yesAdvanced Engineering Materials, EarlyView.
When realized as inserts in high‐pressure die casting, aluminum cooling channels for electric powertrain components and similar applications typically require a stabilizing filler to survive the process. The present study investigates relinquishing this filler using additively manufactured inserts promising performance improvements.
Dirk Lehmhus   +9 more
wiley   +1 more source

Anatomy of null contractions

open access: yesJournal of High Energy Physics
We introduce null contractions of the Poincare and relativistic conformal algebras. The longitudinal null contraction involves writing the algebra in lightcone coordinates and contracting one of the null directions.
Arjun Bagchi, M Nachiketh, Pushkar Soni
doaj   +1 more source

Soft hair of dynamical black hole and Hawking radiation

open access: yesJournal of High Energy Physics, 2018
Soft hair of black hole has been proposed recently to play an important role in the resolution of the black hole information paradox. Recent work has emphasized that the soft modes cannot affect the black hole S-matrix due to Weinberg soft theorems ...
Chong-Sun Chu, Yoji Koyama
doaj   +1 more source

A Simulative Evaluation of Triply Periodic Minimal Surface Structures in the Context of Elastocaloric Applications

open access: yesAdvanced Engineering Materials, EarlyView.
A simulative evaluation of triply periodic minimal surface (TPMS) structures for an elastocaloric application under compressive load is performed. For the evaluation of the structure's performance, surface/volume ratio, generated heat and invested mechanical work are taken into account and are compared to a tube as a reference specimen.
Michael Fries   +3 more
wiley   +1 more source

Poly(1,4‐anthraquinone) as an Organic Electrode Material: Interplay of the Electronic and Structural Properties due to the Unusual Lone‐Pair‐π Conjugation

open access: yesAdvanced Functional Materials, Volume 35, Issue 12, March 18, 2025.
In this study, the unique role of the unusual lone‐pair‐π conjugation mechanism in poly(1,4‐anthraquinone) (P14AQ) is explored as an organic electrode material. Unlike traditional π‐π interactions, P14AQ's conjugation involves lone pairs of oxygen atoms interacting with the π cloud of adjacent units, enabling stable charge transport even with minimal π‐
Xiaotong Zhang, Piotr de Silva
wiley   +1 more source

Removing Homocoupling Defects in Alkoxy/Alkyl‐PBTTT Enhances Polymer:Fullerene Co‐Crystal Formation and Stability

open access: yesAdvanced Functional Materials, EarlyView.
PBTTT‐OR‐R, a C14‐alkoxy/alkyl‐PBTTT polymer derivative, is of substantial interest for optoelectronics due to its specific fullerene intercalation behavior and enhanced charge‐transfer absorption. Comparing this polymer with (S) and without (O) homocoupling defects reveals that PBTTT‐OR‐R(O) forms stable co‐crystals with PC61BM, while PBTTT‐OR‐R(S ...
Zhen Liu   +14 more
wiley   +1 more source

The covariance of chiral fermions theory

open access: yesJournal of High Energy Physics, 2019
The quasiclassical theory of massless chiral fermions is considered. The effective action is derived using time-dependent variational principle which provides a clear interpretation of relevant canonical variables.
K. Andrzejewski   +5 more
doaj   +1 more source

Exploring Dipolar Dynamics and Ionic Transport in Metal‐Organic Frameworks: Experimental and Theoretical Insights

open access: yesAdvanced Functional Materials, EarlyView.
In this study, the interplay of dipolar dynamics and ionic charge transport in MOF compounds is investigated. Synthesizing the novel structure CFA‐25 with integrated freely rotating dipolar groups, local and macroscopic effects, including interactions with Cs cations are explored.
Ralph Freund   +6 more
wiley   +1 more source

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