Pattern of Ionization Gradient, Solar Quiet Magnetic Element, and F 2 ‐Layer Bottomside Thickness Parameter at African Equatorial Location

Radio Science ◽  
2019 ◽  
Vol 54 (5) ◽  
pp. 415-425
Author(s):  
B. O. Adebesin ◽  
J. O. Adeniyi ◽  
I. A. Adimula ◽  
S. J. Adebiyi ◽  
S. O. Ikubanni ◽  
...  
Keyword(s):  
Magnetic Element ◽  
Ionization Gradient ◽  
Thickness Parameter

scholarly journals A novel formulation of 3D Jeffery fluid flow near an irregular permeable surface having chemical reactive species

2021 ◽  
Vol 13 (5) ◽  
pp. 168781402110136
Author(s):  
Mumtaz Khan ◽  
Amer Rasheed ◽  
Shafqat Ali ◽  
Qurat-ul-Ain Azim
Keyword(s):  
Fluid Flow ◽  
Variable Thickness ◽  
Mass Transfer Rate ◽  
Skin Friction Coefficient ◽  
Deborah Number ◽  
Pictorial Representation ◽  
Fluid Temperature ◽  
Flow Parameters ◽  
Opposite Behavior ◽  
Thickness Parameter

The main objective of this paper is to offer a comprehensive study regarding solar radiation and MHD effects on 3D boundary layer Jeffery fluid flow over a non-uniform stretched sheet along with variable thickness, porous medium and chemical reaction of first order are assumed. The system of equations representing temperature, velocity and concentration fields are converted into dimensionless form by introducing dimensionless variables. Thereafter, the aforesaid equations are solved with the help of BVP4C in MATLAB. The numerical results obtained through this scheme are more accurate when compared with those in the existing literature. In order to have a pictorial representation, the effects of material and flow parameters on velocity, temperature and concentration profiles are presented through graphs. Moreover, the numerical values of heat and mass transfer rate and skin friction coefficient are given in tabular form. It is evident from the acquired results, that the velocity offers two fold behavior for variable thickness parameter that is, n < 1 close and away from the non-uniform surface. It is also noted that the axial and transverse velocities show an increasing behavior for Deborah number while the fluid temperature and concentration shows opposite behavior at the same time.

Curium: A new magnetic element

Physica B+C ◽  
1977 ◽  
Vol 86-88 ◽  
pp. 30-31 ◽  
Author(s):  
J.-M. Fournier ◽  
A. Blaise ◽  
W. Muller ◽  
J.-C. Spirlet
Keyword(s):  
Magnetic Element

scholarly journals Persistent magnetic vortex flow at a supergranular vertex

2018 ◽  
Vol 610 ◽  
pp. A84 ◽  
Author(s):  
Iker S. Requerey ◽  
Basilio Ruiz Cobo ◽  
Milan Gošić ◽  
Luis R. Bellot Rubio
Keyword(s):  
Magnetic Fields ◽  
Large Scale ◽  
Vortex Flow ◽  
Spatial Scales ◽  
Magnetic Vortex ◽  
Magnetic Feature ◽  
Magnetic Element ◽  
Flow Maps ◽  
Wide Range ◽  
Intensity Images

Context. Photospheric vortex flows are thought to play a key role in the evolution of magnetic fields. Recent studies show that these swirling motions are ubiquitous in the solar surface convection and occur in a wide range of temporal and spatial scales. Their interplay with magnetic fields is poorly characterized, however. Aims. We study the relation between a persistent photospheric vortex flow and the evolution of a network magnetic element at a supergranular vertex. Methods. We used long-duration sequences of continuum intensity images acquired with Hinode and the local correlation-tracking method to derive the horizontal photospheric flows. Supergranular cells are detected as large-scale divergence structures in the flow maps. At their vertices, and cospatial with network magnetic elements, the velocity flows converge on a central point. Results. One of these converging flows is observed as a vortex during the whole 24 h time series. It consists of three consecutive vortices that appear nearly at the same location. At their core, a network magnetic element is also detected. Its evolution is strongly correlated to that of the vortices. The magnetic feature is concentrated and evacuated when it is caught by the vortices and is weakened and fragmented after the whirls disappear. Conclusions. This evolutionary behavior supports the picture presented previously, where a small flux tube becomes stable when it is surrounded by a vortex flow.

In-Plane Electromagnetic Generator Fabricated on Printed Circuit Board Technology

2013 ◽  
Vol 479-480 ◽  
pp. 524-529
Author(s):  
C.T. Pan ◽  
F.T. Hsu ◽  
C.C. Nien ◽  
Z.H. Liu ◽  
Y.J. Chen ◽  
...  
Keyword(s):  
Printed Circuit Board ◽  
Energy Harvester ◽  
Cost Effective ◽  
Circuit Board ◽  
Outer Diameter ◽  
Magnetic Element ◽  
Induced Voltage ◽  
Element Analysis ◽  
Printed Circuit ◽  
Electromagnetic Generator

Small and efficient energy harvesters, as a renewable power supply, draw lots of attention in the last few years. This paper presents a planar rotary electromagnetic generator with copper coils fabricated by using printed circuit board (PCB) as inductance and Nd-Fe-B magnets as magnetic element. Coils are fabricated on PCB, which is presumably cost-effective and promising methods. 28-pole Nd-Fe-B magnets with outer diameter of 50 mm and thickness of 2 mm was sintered and magnetized, which can provide magnetic field of 1.44 Tesla. This harvester consists of planar multilayer with multi-pole coils and multi-pole permanent magnet, and the volume of this harvester is about 50x50x2.5 mm3. Finite element analysis is used to design energy harvesting system, and simulation model of the energy harvester is established. In order to verify the simulation, experiment data are compared with simulation result. The PCB energy harvester prototype can generate induced voltage 0.61 V and 13.29mW output power at rotary speed of 4,000 rpm.

scholarly journals The atomic process in ferromagnetic Induction

1922 ◽  
Vol 100 (706) ◽  
pp. 449-460 ◽  
Keyword(s):  
Magnetic Particles ◽  
Strong Field ◽  
Molecular Magnets ◽  
Magnetic Element ◽  
Atomic Process ◽  
Dissipation Of Energy ◽  
Unstable Phase ◽  
Complete Alignment ◽  
The Stability ◽  
Ferromagnetic Substance

The object of this paper is to amend, in an important particular, the theory of ferromagnetic induction put forward by me more than 30 years ago, and to describe a new model. That theory was itself a modification of the earlier theory of Weber. To Weber is due the fundamental notion that a substance contains minute particles, each of which acts as a magnet, and that in the process of magnetising a ferromagnetic substance these are turned into more or less complete alignment. The ultimate magnetic particles use to be called “molecular magnets”: we now recognise them as attributes of the atom, not of the molecule, and (in all probability) they derive their magnetic moment from the circulation of electricity in electron orbits or in ring electrons. What turns is not the molecule nor the atom, but something within the atom. The characteristics which distinguish ferromagnetic substances from other paramagnetics are: (1) the much larger amount of magnetism they can acquire under the action of an impressed field; (2) the fact that the acquired magnetism tends towards a saturation limit when the field is progressively increased; (3) the fact that the acquired magnetism shows hysteresis with respect to variations of the field, except in certain small initial changes. Weber’s theory explained (1) and (2). My modification of it explained, in addition, (3) as an effect of the irreversible action which occurs when the equilibrium of a magnetic element becomes unstable through change in the externally impressed magnetic force, and it swings over, with dissipation of energy, into a new position of stability. The stability in both positions is sufficiently explained by magnetic forces only. In breaking away from one stable position it is deflected at first in a quasi­-elastic (reversible) manner until the external force reaches a certain value at which the equilibrium is upset. The essence of hysteresis is the turning from one position of stability to another, through a region of instability. If the conditions are such that there is no unstable phase in the turning, then there is no dissipation of energy, and consequently no hysteresis. This occurs in very feeble magnetisation, when the deflections are reversible; it also occurs if the piece be caused to rotate in a field of great strength. J. Swinburne pointed out that, as a consequence of my theory, hysteresis should vanish when a cylinder of ferromagnetic metal is rotated in a very strong field, and this curious result was confirmed experimentally by F. G. Baily.

A Porous Media Model for Thin Film Lubrication

1995 ◽  
Vol 117 (1) ◽  
pp. 16-21 ◽  
Author(s):  
J. A. Tichy
Keyword(s):  
Reynolds Equation ◽  
Squeezing Flow ◽  
Thin Film Lubrication ◽  
Porous Layers ◽  
Porosity Parameter ◽  
Porous Media Model ◽  
Molecular Length ◽  
Load Increase ◽  
Thickness Parameter ◽  
Film Lubrication

A rheological model has been developed which can be applied to boundary lubrication. The model is applicable to thin films in which the molecular length scale is the same order as the film thickness. The micro structure is simulated by porous layers attached to the contact surfaces. The model contains three material properties: (1) viscosity, (2) the thickness of the porous layer, and (3) a porosity parameter. A modified Reynolds equation is developed. Behavior in two types of contacts is calculated: squeezing flow between crossed cylinders (Chan and Horn’s, 1985 drainage experiment) and a one-dimensional converging wedge contact. The effect of the layer thickness parameter is to increase the load and reduce the friction coefficient. Increasing the porosity parameter value tends to reduce the magnitude of the load increase.

Fully developed Darcy-Forchheimer nanomaterial flow with Cattaneo–Christov (CC) double diffusion model

2020 ◽  
Vol 34 (21) ◽  
pp. 2050214
Author(s):  
M. Ijaz Khan ◽  
M. U. Hafeez ◽  
T. Hayat ◽  
A. Alsaedi
Keyword(s):  
Uniform Magnetic Field ◽  
Series Solution ◽  
Magnetic Parameter ◽  
Concentration Field ◽  
Velocity Slip ◽  
Double Diffusion ◽  
Surface Drag ◽  
Flow Parameters ◽  
Permeability Parameter ◽  
Thickness Parameter

The current work examines the MHD convective stagnation point flow of nanofluid over a stretched surface. A uniform magnetic field is applied in a transverse direction. Darcy–Forchheimer’s relation is accounted to demonstrate the flow nature in a permeable medium. Cattaneo–Christov heat and mass flux expressions are incorporated in the modeling. Velocity slip conditions are taken. The non-dimensional velocity, temperature and concentration field are analyzed via pertinent flow parameters like permeability parameter, Buoyancy or mixed convection variable, magnetic parameter, Prandtl number and surface thickness parameter. Results are tabulated for the surface drag force. The Homotopic technique is utilized for the series solution of differential system.

Magnetization reversal models for a magnetic element, the ?integral comb?

1968 ◽  
Vol 11 (2) ◽  
pp. 13-18
Author(s):  
V. E. Batshever ◽  
A. I. Drokin
Keyword(s):  
Magnetization Reversal ◽  
Magnetic Element

Electronic Structure and Magnetic Properties of Ti-doped ZnO

2009 ◽  
Vol 1183 ◽  
Author(s):  
Soumia Lardjane ◽  
Ghouti Merad ◽  
Houda Imane Faraoun
Keyword(s):  
Density Functional ◽  
Room Temperature ◽  
Magnetic Semiconductor ◽  
Magnetic Element ◽  
Functional Theory ◽  
Magnetic Structures ◽  
Spintronic Devices ◽  
The Density Functional Theory ◽  
Doped Zno ◽  
Ferromagnetic Ordering

AbstractRecent experiments suggest that Ti doped ZnO can be a promising room temperature dilute magnetic semiconductor (DMS) and a potentially useful material for spintronic devices. Furthermore, the fact that Ti doped ZnO shows ferromagnetic behaviour despite it contains no magnetic element makes this system good candidate for theoretical investigation regarding the controversies about the origin of ferromagnetic ordering in TM-doped ZnO. In this work, the density functional theory (DFT) is used to calculate the electronic and magnetic structures of Ti-doped ZnO. The obtained results are used to discuss the origin of the ferromagnetism, and the contribution of different atoms in the magnetic moment.

Sign in / Sign up

Export Citation Format

Share Document