Structure of the Bloch wall in multilayers

2005 ◽  
Vol 461 (2058) ◽  
pp. 1911-1926 ◽  
Author(s):  
Carlos J García-Cervera
Keyword(s):  
Film Thickness ◽  
Magnetic Materials ◽  
Double Layer ◽  
Dimensional Reduction ◽  
Interlayer Spacing ◽  
Optimal Shape ◽  
Bloch Wall ◽  
One Dimensional ◽  
The Core ◽  
The One

We present an analysis of the structure of Bloch walls in layered magnetic materials in the context of micromagnetics. We have obtained the Γ -limit of a one-dimensional reduction of the Landau–Lifshitz energy for a double layer in several asymptotic regimes. As a result, the optimal energy, the core length and the optimal shape of the Bloch wall have been determined. The effects of the interlayer spacing and the film thickness are studied. A comparison between the structure of the Bloch and Néel walls in multilayers is carried out. We illustrate all our findings by numerically minimizing the one-dimensional energy.

Numerical model of plasma double layers using the Vlasov equation

1980 ◽  
Vol 23 (3) ◽  
pp. 433-452 ◽  
Author(s):  
Lloyd E. Johnson
Keyword(s):  
Magnetic Field ◽  
Double Layer ◽  
Axial Magnetic Field ◽  
Double Layers ◽  
Plasma Region ◽  
Langmuir Waves ◽  
One Dimensional ◽  
Poisson Equations ◽  
The One ◽  
Do So

The one-dimensional plasma double layer is modelled by numerically integrating the time-dependent Vlasov and Poisson equations. A constant magnetic field at an arbitrary angle with respect to the layer is included. The model shows that such a plasma region can generate as well as reflect Langmuir waves and shows how RF emission may arise. An axial magnetic field does not inhibit the formation of a double layer, although a non-axial field may do so.

High-Fidelity Rendering of Contact With Virtual Objects

2015 ◽  
Vol 137 (7) ◽  
Author(s):  
Arash Mohtat ◽  
József Kövecses
Keyword(s):  
Contact Force ◽  
Constitutive Relations ◽  
Sampling Rate ◽  
Smooth Transition ◽  
Virtual Object ◽  
High Fidelity ◽  
Unified Approach ◽  
One Dimensional ◽  
The Core ◽  
The One

When interacting with a virtual object (VO) through a haptic device, it is crucial to feedback a contact force to the human operator (HO) that displays the VO physical properties with high fidelity. The core challenge, here, is to expand the renderable range of these properties, including larger stiffness and smaller inertia, at the available sampling rate. To address this challenge, a framework entitled high-fidelity contact rendering (HFCR) has been developed in this paper. The framework consists of three main strategies: an energy-based rendering of the contact force, smooth transition (ST) between contact modes, and remaining leak dissipation (LD). The essence of these strategies is to make the VO emulate its continuous-time counterpart. This is achieved via physically meaningful modifications in the constitutive relations to suppress artificial energy leaks. The strategies are first developed for the one-dimensional (1D) canonical VO; then, generalization to the multivariable case is discussed. Renderability has been analyzed exploring different stability criteria within a unified approach. This leads to stability charts and identification of renderable range of properties in the presence and absence of the HO. The framework has been validated through simulation and various experiments. Results verify its promising aspects for various scenarios including sustained contact and sudden collision events with or without the HO.

The One-Dimensional Optimum Hydrodynamic Gas Slider Bearing

1968 ◽  
Vol 90 (1) ◽  
pp. 281-284 ◽  
Author(s):  
C. J. Maday
Keyword(s):  
Film Thickness ◽  
Load Capacity ◽  
Maximum Load ◽  
Slider Bearing ◽  
Compression Process ◽  
One Dimensional ◽  
One Step ◽  
The Difference ◽  
The One ◽  
Bearing Number

Bounded variable methods of the calculus of variations are used to determine the optimum or maximum load capacity hydrodynamic one-dimensional gas slider bearing. A lower bound is placed on the minimum film thickness in order to keep the load finite, and also to satisfy the boundary conditions. Using the Weierstrass-Erdmann corner conditions and the Weierstrass E-function it is found that the optimum gas slider bearing is stepped with a convergent leading section and a uniform thickness trailing section. The step location and the leading section film thickness depend upon the bearing number and compression process considered. It is also shown that the bearing contains one and only one step. The difference in the load capacity and maximum film pressure between the isothermal and adiabatic cases increases with increasing bearing number.

A New Theory of Elastic Sandwich Plates—One-Dimensional Case

1959 ◽  
Vol 26 (3) ◽  
pp. 415-421
Author(s):  
Yi-Yuan Yu
Keyword(s):  
Infinite Plate ◽  
Theory Of Elasticity ◽  
Dimensional Case ◽  
Transverse Shear Deformation ◽  
Sandwich Plates ◽  
Rotatory Inertia ◽  
One Dimensional ◽  
The Core ◽  
The One ◽  
Final Equation

Abstract A new flexural theory of isotropic elastic sandwich plates is deduced from the theory of elasticity. The one-dimensional case is presented in this paper. The theory includes the effects of transverse-shear deformation and rotatory inertia in both the core and faces of the sandwich, and no limitation is imposed upon the magnitudes of the ratios between the thicknesses, material densities, and elastic constants of the core and faces of the sandwich. The method used is an extension of one due to Mindlin [1], and the results reduce to those of his for the corresponding homogeneous plates as special limiting cases. A final equation also may be simplified and reduced to the corresponding results of Reissner [2], Hoff [3], and Eringen [4] for the bending of ordinary sandwich plates that have thin faces. Results of the theory are applied to the problem of bending of a cantilever plate subjected to load at the unsupported end and to the problem of propagation of straight-crested waves in an infinite plate.

scholarly journals OCTONIONIC REALIZATIONS OF ONE-DIMENSIONAL EXTENDED SUPERSYMMETRIES: A CLASSIFICATION

2003 ◽  
Vol 18 (11) ◽  
pp. 787-798 ◽  
Author(s):  
H. L. CARRION ◽  
M. ROJAS ◽  
F. TOPPAN
Keyword(s):  
Dynamical Systems ◽  
Dimensional Reduction ◽  
Spinning Particles ◽  
One Dimensional ◽  
The One ◽  
M Theory

The classification of the octonionic realizations of the one-dimensional extended supersymmetries is here furnished. These are non-associative realizations which, albeit inequivalent, are put in correspondence with a subclass of the already classified associative representations for 1D extended supersymmetries. Examples of dynamical systems invariant under octonionic realizations of the extended supersymmetries are given. We cite among the others the octonionic spinning particles, the N = 8 KdV , etc. Possible applications to supersymmetric systems arising from dimensional reduction of the octonionic superstring and M-theory are mentioned.

scholarly journals Compound viscous thread with electrostatic and electrokinetic effects

2012 ◽  
Vol 701 ◽  
pp. 171-200 ◽  
Author(s):  
D. T. Conroy ◽  
O. K. Matar ◽  
R. V. Craster ◽  
D. T. Papageorgiou
Keyword(s):  
Electric Field ◽  
Fluid Viscosity ◽  
One Dimensional ◽  
The Core ◽  
Jet Breakup ◽  
Voltage Potential ◽  
Leaky Dielectric Model ◽  
Model Equations ◽  
The One ◽  
Wave Limit

AbstractBreakup of an electrified viscous compound jet, surrounded by a dielectric gas, is investigated theoretically. The fluids are considered to be electrolytes and the core fluid viscosity is assumed to be much larger than that of the annular fluid. Axisymmetric configurations are considered with the three fluids bound by a cylindrical electrode that is held at a constant voltage potential. The model equations are investigated asymptotically in the long-wave limit, yielding two cases corresponding to a negligible surface charge with electrokinetic effects and a leaky dielectric model. A linear stability analysis for both cases is performed and the electrical effects are found to have a stabilizing effect, which is consistent with previous investigations of single electrified jet breakup at small wavenumbers. The one-dimensional equations are also solved numerically. The electric field is found to cause satellite formation in the core fluid, which does not occur in the purely hydrodynamic case, with the satellite size increasing with the strength of the electric field.

scholarly journals From Simmel to Relational Sociology

2020 ◽  
Author(s):  
Sophie Mützel ◽  
Lisa Kressin
Keyword(s):  
Social Network ◽  
The Other ◽  
Georg Simmel ◽  
Relational Sociology ◽  
Sociology Of Culture ◽  
Cultural Issues ◽  
One Dimensional ◽  
The Core ◽  
The Past ◽  
The One

Georg Simmel (1858-1918), who is widely regarded as one of the classics and intellectual grandfathers of sociology, has written on a variety of topics from several disciplinary perspectives. Yet despite the breadth and richness of his work, current sociology typically focuses only on individual dimensions. On the one hand, Simmel’s work is seen as foundational to a formal sociology, which is at the core of social network analysis. On the other hand, Simmel’s works on cultural issues yield astute analyses of modernity, which is why they are classics in the sociology of culture. However, such one-dimensional interpretations of Simmel’s work appear limited and in turn do not sufficiently capture his influence on the field of sociology. This chapter claims that the separated readings of the “two Simmels” need to be brought together to make full analytical use of Simmel’s most important heuristic distinction: form and content. Moreover, we will show that relational sociology of the past four decades has moved in that direction by taking the interrelation of structure and meaning seriously.

Control of Ferroelectric Properties of PbZrxTi1−xO3 Thin Film for Electron Emission Device Driven by Low Voltage

1998 ◽  
Vol 541 ◽  
Author(s):  
Y. Yamagata ◽  
M. Yamazato ◽  
T. Ikegami ◽  
K. Ebihara ◽  
J. Narayan ◽  
...  
Keyword(s):  
Electric Field ◽  
Film Thickness ◽  
Ferroelectric Phase ◽  
Low Voltage ◽  
Ferroelectric Properties ◽  
Domain Growth ◽  
One Dimensional ◽  
Pzt Films ◽  
The One ◽  
Coercive Electric Field

AbstractEpitaxial PbZr0.52TiO0.48O3/YBa2Cu3O7−x heterostructures on Nd:YAlO3 and MgO substrates were fabricated by KrF pulsed laser deposition. The coercive electric field of the PZT films increased with decrease of the film thickness from 1.2 μm to 0.04 μm, while the magnitude of spontaneous polarization was almost constant in this thickness range. It was found that the dependence of the film thickness d on the coercive electric field Ec was Ecæ d−2/3. This results from that the PZT/YBCO heterostructure has the one dimensional ferroelectric domain growth without non-ferroelectric phase. The polarization of AuIPZT/YBCO/(MgO or YAlO) capacitors can be changed by the applied voltage below 5 V.

The Foundation of the Sommerfeld Transformation

2002 ◽  
Vol 124 (3) ◽  
pp. 645-646 ◽  
Author(s):  
Clarence J. Maday
Keyword(s):  
Solar System ◽  
Film Thickness ◽  
Journal Bearing ◽  
Closed Orbit ◽  
True Anomaly ◽  
Central Angle ◽  
Eccentric Anomaly ◽  
One Dimensional ◽  
Analytic Singularity ◽  
The One

The analysis of the one-dimensional journal bearing leads to an interesting integral that is continuous but has an analytic singularity involving the inverse tangent at π/2. This difficulty was resolved by a clever and non-intuitive transformation attributed to Sommerfeld. In this technical brief we show that the transformation has its origin in the geometry of the ellipse and Kepler’s equation that is based upon his observations of the planets in the Solar system. The derivation of the transformation is a problem or exercise in Sommerfeld’s monograph, Mechanics. The transformation is the relation between the two angles that characterize the ellipse, the closed orbit of a body in a central inverse square force field. The angle measured about the focus is the true anomaly (angle) and the angle measured about the center is the eccentric anomaly (angle). We establish the analogy between the orbital radius in terms of the eccentric anomaly and the film thickness of the journal bearing in terms of its central angle.

A Variational Principle Applied to the Plane Slider Bearing

1965 ◽  
Vol 87 (4) ◽  
pp. 1081-1082
Author(s):  
Clarence J. Maday
Keyword(s):  
Variational Principle ◽  
Film Thickness ◽  
Power Loss ◽  
Minimum Principle ◽  
Slider Bearing ◽  
One Dimensional ◽  
Dimensional Plane ◽  
Minimum Film Thickness ◽  
The One ◽  
Made In

A minimum principle from hydrodynamics is applied to the one-dimensional plane slider bearing which is provided with a self-seeking pivot mechanism. An analysis was made in which a certain integral was minimized subject to the constraint that the load, speed, and viscosity were held fixed. This analysis showed that this corresponded exactly to that combination of minimum film thickness and inclination which would minimize the power loss subject to the above-mentioned constraint. It was also found that, in order to satisfy the minimum principle, there exists a definite numerical ratio between the slider inclination and the nondimensional minimum film thickness. This, in turn, fixed the pivot location relative to the length of the slider.

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