Results 71 to 80 of about 63,236 (296)

Singularity in Gravitational Collapse of Plane Symmetric Charged Vaidya Spacetime

, 2010
We study the final outcome of gravitational collapse resulting from the plane symmetric charged Vaidya spacetime. Using the field equations, we show that the weak energy condition is always satisfied by collapsing fluid.
AISHA SIDDIQA, D'Inverno R., Joshi P. S., Kramer D., M. SHARIF, Papapetrou A., Penrose R., Sharma A. K., Virbhadra K. S., Zade S. S.   +9 more
core   +1 more source

Multi‐scale Engineered Vasculature and Hierarchical Porosity via Volumetric Bioprinting‐Guided Photopolymerization‐Induced Phase Separation

Advanced Materials, EarlyView.
Vascularization in bioprinted hydrogels is limited by nanoscale porosity in hydrogel bionks. Volumetric bioprinting of gelatin–norbornene phase‐separating hydrogels permits to create centimeter‐scale constructs featuring interconnected multi‐scale porosity. Light dose gradients result in spatially controlled pore dimensions. Capillary‐scale vessels are
Oksana Y. Dudaryeva, Maj‐Britt Buchholz, Gabriel Größbacher, Sofia Amaral, Sammy Florczak, Camille Bonhomme, Alvaro Rojo Ferrer, Mark W. Tibbitt, Riccardo Levato   +8 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

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

Strategies for Enhancing Thermal Conductivity of PDMS in Electronic Applications

Advanced Materials Technologies, EarlyView.
This review explores effective strategies for enhancing heat dissipation in Polydimethylsiloxane (PDMS)‐based composites, focusing on particle optimization, 3D network design, and multifunctional integration. It offers key insights into cutting‐edge methods and simulations that are advancing thermal management in modern electronic devices.
Xiang Yan, Marisol Martin‐Gonzalez
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

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

Recent Advances in Variable‐Stiffness Robotic Systems Enabled by Phase‐Change Materials

Advanced Robotics Research, EarlyView.
Phase‐change materials (PCMs), such as shape memory alloys, hydrogels, shape memory polymers, liquid crystal elastomers, and low‐melting‐point alloys, are driving advancements in stiffness‐tunable robotic systems across a wide range of applications. This review highlights recent progress in PCM‐enabled robotics, focusing on their underlying mechanisms,
Sukrit Gaira, Liao Wu, Ming Li, Priyank Kumar, Xiaopeng Li, Shi‐Yang Tang   +5 more
wiley   +1 more source

On the Role of Initial Data in the Gravitational Collapse of Inhomogeneous Dust

, 1995
We consider here the gravitational collapse of a spherically symmetric inhomogeneous dust cloud described by the Tolman-Bondi models. By studying a general class of these models, we find that the end state of the collapse is either a black hole or a ...
A. C. Newman, D. Christodoulou, D. M. Eardley, H. Bondi, I. H. Dwivedi, J. R. Oppenheimer, P. S. Joshi, P. S. Joshi, P. S. Joshi, R. C. Tolman, R. Penrose, T. P. Singh   +11 more
core   +1 more source

Soft Robotic Snake with Tunable Undulatory Gait for Efficient Underwater Locomotion

Advanced Robotics Research, EarlyView.
This study designs an underwater soft snake robot using 3D‐printed soft actuators, controlled by specific signals to generate sinusoidal undulation. Results show a positive correlation between speed and swing amplitude, with optimal performance at 2/3π phase offset, PLA tail, 1.2 voltage growth rate, and 6s undulation period achieving a maximum speed ...
Huichen Ma, Junjie Zhou, Raye Yeow
wiley   +1 more source