Gravitation collapse of spherical symmetry with non-uniform density

2006 ◽  
Vol 1 (2) ◽  
pp. 161-168 ◽  
Author(s):  
Gu Chao-hao
Keyword(s):  
Spherical Symmetry ◽  
Uniform Density

Modeling of Shock Propagation in Non-uniform Density Media

2020 ◽  
Author(s):  
Yifeng Tian ◽  
Farhad A. Jaberi ◽  
Daniel Livescu
Keyword(s):  
Shock Propagation ◽  
Uniform Density

scholarly journals Horizons as boundary conditions in spherical symmetry

2019 ◽  
Vol 100 (6) ◽  
Author(s):  
Sharmila Gunasekaran ◽  
Ivan Booth
Keyword(s):  
Boundary Conditions ◽  
Spherical Symmetry

scholarly journals Atomic Layer Deposition of Ni-Co-O Thin-Film Electrodes for Solid-State LIBs and the Influence of Chemical Composition on Overcapacity

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 907
Author(s):  
Yury Koshtyal ◽  
Ilya Mitrofanov ◽  
Denis Nazarov ◽  
Oleg Medvedev ◽  
Artem Kim ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Atomic Layer Deposition ◽  
Nickel Oxide ◽  
Cobalt Oxide ◽  
Lithium Ion ◽  
Atomic Layer ◽  
Metallic Nickel ◽  
Uniform Density ◽  
Oxide Content ◽  
Layer Deposition

Nanostructured metal oxides (MOs) demonstrate good electrochemical properties and are regarded as promising anode materials for high-performance lithium-ion batteries (LIBs). The capacity of nickel-cobalt oxides-based materials is among the highest for binary transition metals oxide (TMOs). In the present paper, we report the investigation of Ni-Co-O (NCO) thin films obtained by atomic layer deposition (ALD) using nickel and cobalt metallocenes in a combination with oxygen plasma. The formation of NCO films with different ratios of Ni and Co was provided by ALD cycles leading to the formation of nickel oxide (a) and cobalt oxide (b) in one supercycle (linear combination of a and b cycles). The film thickness was set by the number of supercycles. The synthesized films had a uniform chemical composition over the depth with an admixture of metallic nickel and carbon up to 4 at.%. All samples were characterized by a single NixCo1-xO phase with a cubic face-centered lattice and a uniform density. The surface of the NCO films was uniform, with rare inclusions of nanoparticles 15–30 nm in diameter. The growth rates of all films on steel were higher than those on silicon substrates, and this difference increased with increasing cobalt concentration in the films. In this paper, we propose a method for processing cyclic voltammetry curves for revealing the influence of individual components (nickel oxide, cobalt oxide and solid electrolyte interface—SEI) on the electrochemical capacity. The initial capacity of NCO films was augmented with an increase of nickel oxide content.

scholarly journals 3-D flow of a compressible viscous micropolar fluid with spherical symmetry: Regularity of the solution

2016 ◽  
Vol 438 (1) ◽  
pp. 162-183 ◽  
Author(s):  
Ivan Dražić ◽  
Loredana Simčić ◽  
Nermina Mujaković
Keyword(s):  
Spherical Symmetry ◽  
Micropolar Fluid

scholarly journals Dynamics of a spherical object of uniform density in an expanding universe

2013 ◽  
Vol 88 (4) ◽  
Author(s):  
Roshina Nandra ◽  
Anthony N. Lasenby ◽  
Michael P. Hobson
Keyword(s):  
Uniform Density ◽  
Expanding Universe ◽  
Spherical Object

Modelling of the Development of the Vertical Density Profile of MDF during Hot Pressing

2007 ◽  
Vol 2 (2) ◽  
Author(s):  
Arun Gupta ◽  
Patrick Jordan ◽  
Shusheng Pang
Keyword(s):  
Moisture Content ◽  
Density Profile ◽  
Hot Pressing ◽  
Major Influence ◽  
Transfer Model ◽  
Uniform Density ◽  
Moisture Movement ◽  
Vertical Density Profile ◽  
Vertical Density ◽  
Pressing Operation

The hot pressing operation is one of the most important operations in medium density fibreboard (MDF) manufacture. Complicated dynamic interactions occur during pressing, including heat transfer, moisture movement, development of gas pressure, internal stress development and relaxation, wood consolidation, resin curing, bonding between particles and eventual development of a non-uniform density distribution through the panel thickness. Consequently the mat experiences continuously changing internal conditions (temperature and moisture content) as the pressing operation proceeds. The vertical density profile (VDP) has a major influence on the MDF strength and physical properties. This influence of the VDP on the board properties is generally recognised, but the formation of the density profile and their specific effects on the board performance have proved difficult to quantify. A mathematical model based on theoretical analysis and experimental information is being developed. In the model, the mat is divided into a number of thin parallel layers. The deformation of each layer is a function of stress, temperature and moisture content of the layer. The model incorporates the variation of the mat mechanical and rheological properties with moisture content and temperature. The changes in temperature and moisture content are provided by a separate heat and mass transfer model. The present model can predict stress, strain, layer deformation and density across the thickness during pressing. The performance of the model was validated by experiments conducted in a pilot-scale press. Twelve MDF boards were made with different pressing parameters, and the VDP were measured and compared with the simulation results from the model. The model could predict the density profile with an acceptable accuracy for the main variables that control the manufacturing of MDF boards.

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