Critical point in the strong-field magnetotransport of a three-dimensional binary disordered composite medium

2008 ◽  
Vol 77 (14) ◽  
Author(s):  
Ronen Magier ◽  
David J. Bergman
2019 ◽  
Vol 62 (4) ◽  
pp. 263-269
Author(s):  
I. A. Pribytkov ◽  
S. I. Kondrashenko

In this paper, the development features of a single free jet of hightemperature nitrogen interacting with a flat surface were studied. Calculation of the heat exchange process during heating by the attacking jets is very difficult to implement analytically due to complexity of the gas-dynamic processes occurring both in a single jet and in a system of jets interacting with the metal. The computational difficulties are aggravated by the fact that when interacting with the surface the jet as such disappears. The flat (fan) flow interacts with the surface: form, aerodynamic properties and thermal state of the flow strongly differ from those of the original jet. The studies were conducted on the basis of numerical simulation in the FloEFD software and computing complex for multiphysical simulation based on solution of the equations of gas dynamics and heat transfer. The solved system of equations consisted of Navier-Stokes equations, equations of energy and continuity and was supplemented by k – ε turbulence model. A three-dimensional model was developed for simulation, the necessary properties, initial and boundary conditions were specified. In the study of aerodynamics of a single high-temperature jet interacting with the surface, the main defining values were: nitrogen flow rate from the nozzle U0 , nitrogen temperature T, internal diameter of the nozzle d0 , distance from the nozzle section to the surface h, distance from the critical point (point of intersection of the jet axis with the surface) along the flow radius r. Data on the gas velocity decrease as the jet develops due to the loss of initial energy to engage the motionless surrounding gas in motion, is presented. The studies have shown that increase in the initial velocity of gas outflow brings the area of higher velocities closer to the surface both in the jet itself and in the fan jet. This factor contributes to heat transfer intensification. In addition, high speeds increase the total thickness of the fan flow and reduce the thickness of hydrodynamic boundary layer, which increases with distance from the critical point.


2014 ◽  
Vol 29 (33) ◽  
pp. 1450159
Author(s):  
Hua Jiang ◽  
Yong-Long Wang ◽  
Wei-Tao Lu ◽  
Chuan-Cong Wang

We determine the critical fermion flavor for dynamical chiral symmetry breaking in three-dimensional quantum electrodynamics using nonlocal gauge (gauge parameter depends on the momentum or coordinate). The coupled Dyson–Schwinger equations of the fermion and gauge boson propagators are considered in the vicinity of the critical point. Illustrated by using the transverse vertex proposed by Bashir et al., we show that: for a variety of the transverse vertex, the critical flavor is still 128/3π2, the same as using the bare vertex.


2020 ◽  
Vol 21 (9) ◽  
pp. 3271 ◽  
Author(s):  
Takuki Komenami ◽  
Akihiro Yoshimura ◽  
Yasunari Matsuno ◽  
Mari Sato ◽  
Chikara Sato

We developed a liquid-phase synthesis method for Pd-based nanostructure, in which Pd dissolved in dimethyl sulfoxide (DMSO) solutions was precipitated using acid aqueous solution. In the development of the method, in situ monitoring using atmospheric scanning electron microscopy (ASEM) revealed that three-dimensional (3D) Pd-based nanonetworks were deformed to micrometer-size particles possibly by the surface tension of the solutions during the drying process. To avoid surface tension, critical point drying was employed to dry the Pd-based precipitates. By combining ASEM monitoring with critical point drying, the synthesis parameters were optimized, resulting in the formation of lacelike delicate nanonetworks using citric acid aqueous solutions. Precipitation using HCl acid aqueous solutions allowed formation of 500-nm diameter nanorings connected by nanowires. The 3D nanostructure formation was controllable and modifiable into various shapes using different concentrations of the Pd and Cl ions as the parameters.


2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Abbas Bahri ◽  
Yongzhong Xu

AbstractIn this paper we study a functional at infinity associated to a contact form on a three dimensional manifold. The Morse index of this functional at infinity can be decomposed into two parts, one along the characteristic manifold and the other along the normal directions. We prove that we can redistribute the negative directions between the two subspaces through a local deformation of the contact form near a critical point at infinity.


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