Smoke-Ring Solutions of Gierer–Meinhardt System in $\mathbb{R}^{3}$

2011 ◽  
Vol 10 (1) ◽  
pp. 251-277 ◽  
Author(s):  
Theodore Kolokolnikov ◽  
Xiaofeng Ren
Keyword(s):  
Smoke Ring

Transient electromagnetic fields of a buried horizontal magnetic dipole

Geophysics ◽  
2016 ◽  
Vol 81 (6) ◽  
pp. E481-E491 ◽  
Author(s):  
Andrei Swidinsky ◽  
Misac Nabighian
Keyword(s):  
Electric Field ◽  
Magnetic Dipole ◽  
Time Domain ◽  
Major Axis ◽  
Secondary Response ◽  
Burial Depth ◽  
Transient Electromagnetic ◽  
The Earth ◽  
Smoke Ring ◽  
Electromagnetic Surveys

Electromagnetic surveys using a vertical transmitter loop are common in land, marine, and airborne geophysical exploration. Most of these horizontal magnetic dipole (HMD) systems operate in the frequency domain, measuring the time derivative of the induced magnetic fields, and therefore a majority of studies have focused on this subset of field measurements. We examine the time-domain electromagnetic response of a HMD including the electric fields and corresponding smoke rings produced in a conductive half-space. Cases of a dipole at the surface and buried within the earth are considered. Results indicate that when the current in the transmitter is rapidly switched off, a single smoke ring is produced within the plane of the vertical transmitter loop, which is then distorted by the air-earth interface. In this situation, the circular smoke ring, which would normally diffuse symmetrically away from the source in a whole space, is approximately transformed into an ellipse, with a vertical major axis at an early time and a horizontal major axis at a late time. As measured from the location of the transmitter, the depth of investigation and lateral footprint of such a system increases with burial depth. It is also observed that the electric field measured in the direction of the magnetic dipole only contains a secondary response related to the charge accumulation on any horizontal conductivity boundaries because the primary field is always absent. This field component can be expressed analytically in terms of a static and time-varying field, the latter term adding spatial complexity to the total horizontal electric field at the earth surface at early times. Applications of this theoretical study include the design of time-domain induction-logging tools, crossborehole electromagnetic surveys, underground mine expansion work, mine rescue procedures, and novel marine electromagnetic experiments.

Smoke ring aggregates in anterior chamber

2021 ◽  
Vol 1 (4) ◽  
pp. 861
Author(s):  
Seema Meena ◽  
Sandeep Choudhary ◽  
Sonalika Gogia
Keyword(s):  
Anterior Chamber ◽  
Smoke Ring

Transient fields of a current loop source above a layered earth

Geophysics ◽  
1982 ◽  
Vol 47 (7) ◽  
pp. 1068-1077 ◽  
Author(s):  
G. M. Hoversten ◽  
H. F. Morrison
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Electric Fields ◽  
Current Loop ◽  
Wave Form ◽  
Sign Reversal ◽  
Circular Loop ◽  
Single Ring ◽  
Smoke Ring ◽  
A Current

The electric field induced within four layered models by a repetitive current wave form in a circular loop transmitter is presented along with the resulting magnetic fields observed on the surface. The behavior of the induced electric field as a function of time explains the observed sign reversal of the vertical magnetic field on the surface. In addition, the differences between magnetic field responses for different models are explained by the behavior of the induced electric fields. The pattern of the induced electric field is shown to be that of a single “smoke ring,” as described by Nabighian (1979), which is distorted by layering but which remains a single ring system rather than forming separate smoke rings in each layer.

Smoke Ring Physics

2011 ◽  
Vol 49 (8) ◽  
pp. 488-491 ◽  
Author(s):  
Elisha Huggins
Keyword(s):  
Smoke Ring

The Smoke Ring: Tobacco, Money and Multinational Politics

1985 ◽  
Vol 6 (1) ◽  
pp. 137 ◽  
Author(s):  
Harvey A. Risch ◽  
Peter Taylor
Keyword(s):  
Smoke Ring

scholarly journals Structure of the native supercoiled flagellar hook as a universal joint

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Takayuki Kato ◽  
Fumiaki Makino ◽  
Tomoko Miyata ◽  
Péter Horváth ◽  
Keiichi Namba
Keyword(s):  
Image Analysis ◽  
Basal Body ◽  
Single Particle ◽  
Particle Image ◽  
Three Dimensional ◽  
Universal Joint ◽  
Density Map ◽  
Smoke Ring ◽  
Intersubunit Interactions ◽  
Rotary Motor

AbstractThe Bacterial flagellar hook is a short supercoiled tubular structure made from a helical assembly of the hook protein FlgE. The hook acts as a universal joint that connects the flagellar basal body and filament, and smoothly transmits torque generated by the rotary motor to the helical filament propeller. In peritrichously flagellated bacteria, the hook allows the filaments to form a bundle behind the cell for swimming, and for the bundle to fall apart for tumbling. Here we report a native supercoiled hook structure at 3.6 Å resolution by cryoEM single particle image analysis of the polyhook. The atomic model built into the three-dimensional (3D) density map reveals the changes in subunit conformation and intersubunit interactions that occur upon compression and extension of the 11 protofilaments during their smoke ring-like rotation. These observations reveal how the hook functions as a dynamic molecular universal joint with high bending flexibility and twisting rigidity.

scholarly journals A dissolving smoke-ring

Science ◽  
1886 ◽  
Vol ns-8 (179) ◽  
pp. 36-36
Author(s):  
H. W. Parker
Keyword(s):  
Smoke Ring
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