Results 81 to 90 of about 62,947 (343)

In Vivo Skin 3‐D Surface Reconstruction and Wrinkle Depth Estimation Using Handheld High Resolution Tactile Sensing

Advanced Healthcare Materials, EarlyView.
A compact handheld GelSight probe reconstructs in vivo 3‐D skin topography with micron‐level precision using a custom elastic gel and a learning‐based surface normal to height map pipeline. The device quantifies wrinkle depth across various body locations and detects changes in wrinkle depth following moisturizer application.
Akhil Padmanabha, Arpit Agarwal, Catherine Li, Austin Williams, Dinesh K. Patel, Sankalp Chopkar, Achu Wilson, Ahmet Ozkan, Wenzhen Yuan, Sonal Choudhary, Arash Mostaghimi, Zackory Erickson, Carmel Majidi   +12 more
wiley   +1 more source

Particle motion and tidal force in a non-vacuum-charged naked singularity

European Physical Journal C: Particles and Fields
We investigate the gravitational field of a charged, non-vacuum, non-rotating, spherically symmetric body of mass M assuming a static solution to the Einstein–Maxwell field equations.
Divyesh P. Viththani, Ashok B. Joshi, Tapobroto Bhanja, Pankaj S. Joshi   +3 more
doaj   +1 more source

Gravitational perfect fluid collapse in Gauss–Bonnet gravity

European Physical Journal C: Particles and Fields, 2017
The Einstein Gauss–Bonnet theory of gravity is the low-energy limit of heterotic super-symmetric string theory. This paper deals with gravitational collapse of a perfect fluid in Einstein–Gauss–Bonnet gravity by considering the Lemaitre–Tolman–Bondi ...
G. Abbas, M. Tahir
doaj   +1 more source

Why do naked singularities form in gravitational collapse? [PDF]

, 2001
We investigate what are the key physical features that cause the development of a naked singularity, rather than a black hole, as the end-state of spherical gravitational collapse.
A. Krolak, B.C. Nolan, B.J. Carr, C. Gundlach, F. Mena, F.C. Mena, H. Iguchi, N. Dadhich, N. Dadhich, Naresh Dadhich, P.S. Joshi, P.S. Joshi, P.S. Joshi, P.S. Joshi, Pankaj S. Joshi, R. Maartens, R.V. Saraykar, Roy Maartens, S. Jhingan, S. Jhingan, S.G. Ghosh, S.M. Wagh, S.M.C.V. Goncalves, S.S. Deshingkar, T. Harada, T. Harada, T. Harada   +26 more
core   +2 more sources

The Mathematical Origin of Gravitational Singularities

Journal of Modern Physics, 2020
In this note we give a geometrical presentation to the 4D Riemannian curvature as it relates to the Newtonian gravity in the 4D Lorentz manifold. The compacting of the proper time as is necessary for the unification with the Maxwell electrodynamics, as given by Einstein and Kaluza-Klein, should the universe be only of 4D space-time, led to the concept ...
Kai Wai Wong, Wan Ki Chow
openaire   +2 more sources

Beyond Conventional Cooling: Advanced Micro/Nanostructures for Managing Extreme Heat Flux

Advanced Materials, EarlyView.
This review examines the design, application, and manufacturing of biomimetic or engineered micro/nanostructures for managing high heat‐flux in multi‐level electronics by enhancing conductive, convective, phase‐changing, and radiative heat transfer mechanisms, highlighting their potential for efficient, targeted thermal management, and future prospects.
Yuankun Zhang, Huajie Li, Yuhang Zhou, Jun Ma, Keng‐Te Lin, Han Lin, Chunsheng Guo, Baohua Jia   +7 more
wiley   +1 more source

Gravitational lensing by transparent Janis–Newman–Winicour naked singularities

European Physical Journal C: Particles and Fields
The Janis–Newman–Winicour (JNW) spacetime can describe a naked singularity with a photon sphere that smoothly transforms into a Schwarzschild black hole. Our analysis reveals that photons, upon entering the photon sphere, converge to the singularity in a
Deyou Chen, Yiqian Chen, Peng Wang, Tianshu Wu, Houwen Wu   +4 more
doaj   +1 more source

Physical nature of the central singularity in spherical collapse

, 2001
We examine here the nature of the central singularity forming in the spherically symmetric collapse of a dust cloud and it is shown that this is always a strong curvature singularity where gravitational tidal forces diverge powerfully.
B. Waugh, C. J. S. Clarke, C. J. S. Clarke, D. Christodoulou, F. J. Tipler, G. Lemaître, H. Bondi, I. H. Dwivedi, I. H. Dwivedi, I. H. Dwivedi, J. Oppenheimer, P. S. Joshi, P. S. Joshi, P. Yodzis, P. Yodzis, R. C. Tolman, R. Geroch, R. Hagedorn, R. P. A. C. Newman, R. Penrose, S. Jhingan, S. S. Deshingkar, S. W. Hawking, T. Harada   +23 more
core   +2 more sources

Quadruple Helix Inversions of Liquid Crystals Orchestrated by Direct Chirality Transmission of an Intrinsically Chiral Light‐Driven Molecular Machine

Advanced Materials, EarlyView.
A molecular motor with four‐state dynamic chirality is integrated into liquid crystals, enabling quadruple sequential helix inversions and high helical twisting power. Due to high motor efficiency, the supramolecular helicity can be controlled by near‐infrared light via upconversion nanoparticles, resulting in a robust, multistate, photoresponsive soft
Jinyu Sheng, Alexander Ryabchun, Guiying Long, Ben L. Feringa   +3 more
wiley   +1 more source

Gravitational collapse in Rastall gravity

Physics Letters B, 2019
We study spherically symmetric gravitational collapse of a homogeneous perfect fluid in Rastall gravity. Considering a linear equation of state (EoS) for the fluid profiles, we examine the conditions under which the collapse scenario could end in a ...
A. H. Ziaie, H. Moradpour, S. Ghaffari
doaj   +1 more source