scholarly journals The core-radius approach to supercritical fractional perimeters, curvatures and geometric flows

2022 ◽  
Vol 214 ◽  
pp. 112585
Author(s):  
L. De Luca ◽  
A. Kubin ◽  
M. Ponsiglione
Keyword(s):  
Geometric Flows ◽  
Core Radius ◽  
The Core

scholarly journals Optical and X-ray observations of stellar winds in Wolf-Rayet binaries

1995 ◽  
Vol 163 ◽  
pp. 262-270
Author(s):  
A. M. Cherepashchuk
Keyword(s):  
Chemical Composition ◽  
Core Temperature ◽  
Stellar Winds ◽  
Radial Expansion ◽  
Core Radius ◽  
X Ray ◽  
The Core ◽  
Basic Conclusion ◽  
Helium Stars ◽  
Colliding Winds

New spectrophotometric, photometric and polarimetric observations of V444 Cygni confirm the basic conclusion that the WN5 star has a small core radius (rc < 4 R⊙) and a high core temperature (Tc > 60 000 K), which are characteristic of massive helium stars. Values of rc < 3 — 6 R⊙ and Tc > 70 000 — 90 000 K for the core of the WN7 star in the Cygnus X-3 system agree well with this conclusion. A clumping structure of WR winds is suggested. X-ray observations of colliding winds in WR+O binaries suggest radial expansion and anomalous chemical composition of WR winds.

scholarly journals Comparative Analysis of Mathematical Models for Blood Flow in Tapered Constricted Arteries

2012 ◽  
Vol 2012 ◽  
pp. 1-34 ◽  
Author(s):  
D. S. Sankar ◽  
Yazariah Yatim
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Yield Stress ◽  
Flow Rate ◽  
Core Region ◽  
Core Radius ◽  
The Core ◽  
Casson Model ◽  
Longitudinal Impedance ◽  
Two Fluid

Pulsatile flow of blood in narrow tapered arteries with mild overlapping stenosis in the presence of periodic body acceleration is analyzed mathematically, treating it as two-fluid model with the suspension of all the erythrocytes in the core region as non-Newtonian fluid with yield stress and the plasma in the peripheral layer region as Newtonian. The non-Newtonian fluid with yield stress in the core region is assumed as (i) Herschel-Bulkley fluid and (ii) Casson fluid. The expressions for the shear stress, velocity, flow rate, wall shear stress, plug core radius, and longitudinal impedance to flow obtained by Sankar (2010) for two-fluid Herschel-Bulkley model and Sankar and Lee (2011) for two-fluid Casson model are used to compute the data for comparing these fluid models. It is observed that the plug core radius, wall shear stress, and longitudinal impedance to flow are lower for the two-fluid H-B model compared to the corresponding flow quantities of the two-fluid Casson model. It is noted that the plug core radius and longitudinal impedance to flow increases with the increase of the maximum depth of the stenosis. The mean velocity and mean flow rate of two-fluid H-B model are higher than those of the two-fluid Casson model.

Composite Semiconductor Nanoparticles

1992 ◽  
Vol 283 ◽  
Author(s):  
H. S. Zhou ◽  
I. Honma ◽  
H. Komiyama ◽  
J. W. Haus
Keyword(s):  
Electron Diffraction ◽  
Optical Absorption ◽  
Theoretical Calculation ◽  
Band Gap ◽  
Semiconductor Nanoparticles ◽  
Core Radius ◽  
Nanometer Size ◽  
Effective Masses ◽  
The Core ◽  
Semiconductor Particles

ABSTRACTNanometer size semiconductor particles coated with another semiconductor can exhibit unusual and interesting phenomena associated with the redistribution of the electron and hole wavefunctions. Using the band offsets and effective-masses, the band gap as well as the wavefunctions can be altered by changing the core radius of the particles. CdS/PbS coated semiconductor nanoparticles are synthesized by ion displacing method and experimental results are discussed along with the theoretical calculation. Optical absorption as well as TEM, Electron diffraction results provides for the evidence that the particles are coated.

A STUDY OF NUCLEON FORCES WITH REPULSIVE CORES: III. LOW ENERGY PROPERTIES OF THE LÉVY POTENTIAL

1957 ◽  
Vol 35 (4) ◽  
pp. 451-454 ◽  
Author(s):  
M. A. Preston ◽  
J. Shapiro
Keyword(s):  
Binding Energy ◽  
Singlet State ◽  
Scattering Length ◽  
Low Energy ◽  
Proton Scattering ◽  
Core Radius ◽  
Deuteron Binding Energy ◽  
Coupling Constant ◽  
Spin Dependence ◽  
The Core

An attempt has been made to select the core radius and coupling constant of the Lévy potential for the interaction of two nucleons in order to fit the binding energy of the deuteron and the singlet state neutron–proton scattering length. It was found that these two quantities cannot be fitted simultaneously. For any given choice of coupling constant, a somewhat larger core radius is required to fit the deuteron binding energy than is required for the scattering length. This spin dependence of the core radius does not preclude the possibility of a fit to the low energy data with the Lévy potential.

scholarly journals The Core Radius of a Star Cluster Containing a Massive Black Hole

2007 ◽  
Vol 59 (3) ◽  
pp. L11-L14 ◽  
Author(s):  
Douglas C. Heggie ◽  
Piet Hut ◽  
Shin Mineshige ◽  
Junichiro Makino ◽  
Holger Baumgardt
Keyword(s):  
Black Hole ◽  
Star Cluster ◽  
Core Radius ◽  
Massive Black Hole ◽  
The Core

scholarly journals Optical bistability in two-dimensional nonlinear composites of coated cylinders with nonlinear core and graded shell

2020 ◽  
Vol 7 ◽  
pp. 6
Author(s):  
Ya M. Wu ◽  
Guo Q. Chen ◽  
Wen C. Wu ◽  
Yi X. Wang ◽  
Yang Huang
Keyword(s):  
Optical Bistability ◽  
Near Field ◽  
Mean Field ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
Geometrical Parameters ◽  
Core Radius ◽  
The Core ◽  
Nonlinear Composite ◽  
Incident Frequency

The intrinsic optical bistability of the nonlinear composite consisting of coated cylinders with nonlinear core and graded Drude shell is investigated with self-consistent mean-field approximation. We derive the nonlinear equation of near field for such graded composite in the quasistatic limit. We demonstrate that the bistability threshold and the bistable width are highly dependent on the core radius, the incident frequency, and the graded coefficient of the coated cylinder inclusion. It is found that the optical bistability appears only when the core radius and the incident frequency satisfy some specific conditions. Therefore, the optical bistability for nonlinear composite materials may be optimized by the suitable adjustment of the physical and geometrical parameters. Our results may be helpful for the design of the nonlinear device with appropriate bistability.

Estimation of PcP travel times and the depth to the core

1968 ◽  
Vol 58 (4) ◽  
pp. 1293-1303 ◽  
Author(s):  
James Taggart ◽  
E. R. Engdahl
Keyword(s):  
Velocity Distribution ◽  
Core Radius ◽  
Travel Times ◽  
Nuclear Explosions ◽  
Velocity Models ◽  
The Core

Abstract Based on a new P velocity distribution and observed PcP travel times from nuclear explosions, the core is estimated to have a mean radius = 3477 ± 2.0 km (depth = 2894 ± 2.0 km). Five velocity models were tested for the lower-most 90 km of the mantle. The PcP data suggest that the P velocity increases slightly with depth in this region. Tables of PcP travel times have been computed for the preferred model and a core radius of 3477 km.

Self-Induced Velocity of a Vortex Ring Using Straight-Line Segmentation

2014 ◽  
Vol 59 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Mahendra J. Bhagwat ◽  
J. Gordon Leishman
Keyword(s):  
Vortex Ring ◽  
Logarithmic Singularity ◽  
The Self ◽  
Numerical Calculations ◽  
Core Radius ◽  
Line Vortex ◽  
The Core ◽  
Analytical Approximations ◽  
Straight Line ◽  
Induced Velocity

The accuracy of discretized induced velocity calculations that can be obtained using straight-line vortex elements has been reexamined, primarily using the velocity field induced by a vortex ring as a reference. The induced velocity of a potential (inviscid) vortex ring is singular at the vortex ring itself. Analytical results were found by using a small azimuthal cutoff in the Biot–Savart integral over the vortex ring and showed that the singularity is logarithmic in the cutoff. Discrete numerical calculations showed the same behavior, with the self-induced velocity exhibiting a logarithmic singularity with respect to the discretization, which introduces an inherent cutoff in the Biot–Savart integral. Core regularization or desingularization can also eliminate the singularity by using an assumed “viscous” core model. Analytical approximations to the self-induced velocity of a thin-cored vortex ring have shown that the self-induced velocity has a logarithmic singularity in the core radius. It is further shown that the numerical calculations require special treatment of the self-induced velocity caused by curvature, which is lost by the inherent cutoff in the straight-line discretization, to correctly recover this logarithmic singularity in the core radius. Numerical solution using straight-line vortex segmentation, augmented with curved vortex elements only for the self-induced velocity calculation, is shown to be second-order accurate in the discretization.

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