Results 31 to 40 of about 92,362 (201)

Null Geodesic Congruences, Asymptotically-Flat Spacetimes and Their Physical Interpretation

Living Reviews in Relativity, 2009
A priori, there is nothing very special about shear-free or asymptotically shear-free null geodesic congruences. Surprisingly, however, they turn out to possess a large number of fascinating geometric properties and to be closely related, in the context ...
Timothy M. Adamo, Carlos Kozameh, Ezra T. Newman   +2 more
doaj  

Einstein-Cartan theory as a theory of defects in space-time

, 2003
The Einstein-Cartan theory of gravitation and the classical theory of defects in an elastic medium are presented and compared. The former is an extension of general relativity and refers to four-dimensional space-time, while we introduce the latter as a ...
A. Tartaglia, De Wit R., M. L. Ruggiero, Volterra V.   +3 more
core   +1 more source

High‐Entropy Alloy Design Toward Cobalt Substitution for High Hardness and Low Wear Rate Using X–Cr–Fe–Mn–Ni System

Advanced Engineering Materials, EarlyView.
This study explores the replacement of cobalt using the high‐entropy alloy design strategy for wear‐resistant components operating at high temperatures. Starting from the Cantor alloy, cobalt is substituted with Cu, Al, V, or Mo. Metallurgical and tribological analyses reveal that aluminum, vanadium, and molybdenum effectively strengthen the developed ...
Rafaël Jénot, Laurent Peltier, Fodil Meraghni, Mathieu Marquer, Oriane Baulin, Clotilde Macke‐Bart   +5 more
wiley   +1 more source

Null Geodesic Congruences, Asymptotically-Flat Spacetimes and Their Physical Interpretation

Living Reviews in Relativity, 2012
A priori, there is nothing very special about shear-free or asymptotically shear-free null geodesic congruences. Surprisingly, however, they turn out to possess a large number of fascinating geometric properties and to be closely related, in the context ...
Timothy M. Adamo, Ezra T. Newman, Carlos Kozameh   +2 more
doaj  

Nano‐Patterned CuO Nanowire Nanogap Hydrogen Gas Sensor with Voids

Advanced Functional Materials, Volume 35, Issue 12, March 18, 2025.
Sub‐5‐ppb hydrogen (H2) detection and sub‐10‐s response and recovery times are achieved based on nano‐patterned polycrystalline CuO nanowires nanogap gas sensors with voids using electron‐beam lithography and unique annealing processes. Pre‐H2 annealing, void‐generating oxidation, and downscaled nanogap electrodes are key to improving the sensing ...
Muqing Zhao, Ryosuke Nitta, Seiichiro Izawa, Jun‐ichi Yamaura, Yutaka Majima   +4 more
wiley   +1 more source

Thermodynamic Geometry: Evolution, Correlation and Phase Transition

, 2010
Under the fluctuation of the electric charge and atomic mass, this paper considers the theory of the thin film depletion layer formation of an ensemble of finitely excited, non-empty $d/f$-orbital heavy materials, from the thermodynamic geometric ...
Aharony, Aman, Aman, Arcioni, Astefanesei, B.N. Tiwari, Balasubramanian, Balasubramanian, Balasubramanian, Bekenstein, Bellucci, Bellucci, Bellucci, Bellucci, Bellucci, Bellucci, Bellucci, Bellucci, Bellucci, Bloch, Bonora, Callen, Cardoso, Chandra, Chandra, Cross, Dabholkar, Dabholkar, David, de Wit, de Wit, Do Carmo, Emparan, Ferrara, Ferrara, Gaiotto, Gauntlett, Gelfand, Grant, Huang, Iyer, Jatkar, Jiang, Kaura, Krakow, Landau, Mohaupt, Nakahara, Rudin, Ruppeiner, Ruppeiner, Ruppeiner, Ruppeiner, Ruppeiner, Ruppeiner, Ruppeiner, S. Bellucci, Sahoo, Sahoo, Sarkar, Sarkar, Sen, Sen, Sen, Sen, Shen, Sze, Tisza, Venables, Wald, Wald, Weinhold, Weinhold, Widom, Yu, Zelikin   +75 more
core   +1 more source

Ultrahigh Piezoelectricity in Truss‐Based Ferroelectric Ceramics Metamaterials

Advanced Functional Materials, Volume 35, Issue 12, March 18, 2025.
By leveraging the unique combination of polarization direction and loading state, ultrahigh piezoelectricity is achieved through careful tuning of the relative density and scaling ratio in truss‐based ferroelectric metamaterials. This approach enables the simultaneous realization of extremely high piezoelectric constants and ultralow dielectric ...
Jiahao Shi, Kang Ju, Haoyu Chen, Valérie Orsat, Agus P. Sasmito, Ali Ahmadi, Abdolhamid Akbarzadeh   +6 more
wiley   +1 more source

Wearable Haptic Feedback Interfaces for Augmenting Human Touch

Advanced Functional Materials, EarlyView.
The wearable haptic feedback interfaces enhance user experience in gaming, social media, biomedical instrumentation, and robotics by generating tactile sensations. This review discusses and categorizes current haptic feedback interfaces into force, thermal, and electrotactile stimulation‐based haptic feedback interfaces, elucidating their current ...
Shubham Patel, Zhoulyu Rao, Maggie Yang, Cunjiang Yu   +3 more
wiley   +1 more source

4-Dimensional General Relativity from the instrinsic spatial geometry of SO(3) Yang--Mills theory

, 2011
In this paper we derive 4-dimensional General Relativity from three dimensions, using the intrinsic spatial geometry inherent in Yang--Mills theory which has been exposed by previous authors as well as as some properties of the Ashtekar variables.
Ashtekar, Ashtekar, Ashtekar, Bauer, Blagojevic, Capovilla, Eyo Eyo Ita, Freedman, Immirzi, Ita, Penrose, Stephani, Wald, Witten   +13 more
core   +1 more source

Single Pair of Weyl Points Evolve From Spin Group‐Protected Nodal Line in Half‐Metallic Ferromagnet V3S4

Advanced Functional Materials, EarlyView.
A spin group (SG)‐based mechanism is proposed to realize a single pair of Weyl points. PT‐symmetric nodal lines (NLs) persist under T‐breaking, protected by the combination of SG and P symmetry. When considering spin‐orbit coupling, the SG‐protected NL will split into Weyl points, which will also induce anomalous transport phenomena arising from ...
Shifeng Qian, Yao Zhang, Xiaowei Sheng, Xiuxian Yang, Gang Zhang, Junfeng Gao, Xiaotian Wang   +6 more
wiley   +1 more source