Anomalous Behavior of Heterogeneous Materials at Microwaves Frequencies: Introduction to Fractional Derivatives in Electromagnetism

1990 ◽  
Vol 189 ◽  
Author(s):  
F. Heliodore ◽  
D. Cottevieille ◽  
A. Le Mehaute
Keyword(s):  
Electromagnetic Wave ◽  
Physical Meaning ◽  
Fractional Derivatives ◽  
Heterogeneous Media ◽  
Present Note ◽  
Heterogeneous Materials ◽  
Anomalous Behavior ◽  
Point Of View ◽  
Unique Point ◽  
Validity Range

ABSTRACTThe present note introduces new trends in electromagnetic spectroscopy in complex media.When an electromagnetic wave propagates in heterogeneous media, some questions arise about both physical meaning and validity range of the traditional analysis. The aim of our advanced research is related to the generalisation of Maxwell's equations able todescribe both homogeneous and heterogeneous media from an unique point of view.

Electron Pairing and Chemical Bonds. Physical Meaning of Effective Pairs

1994 ◽  
Vol 59 (12) ◽  
pp. 2567-2578 ◽  
Author(s):  
Robert Ponec ◽  
Filip Uhlík
Keyword(s):  
Density Distribution ◽  
Electron Density ◽  
Physical Meaning ◽  
Electron Density Distribution ◽  
Mutual Coupling ◽  
Population Analysis ◽  
Point Of View ◽  
Chemical Bonds ◽  
Conditional Probabilities ◽  
Electron Pairing

The physical meaning of the so-called effective pairs which have been introduced recently within the formalism of pair population analysis is discussed using the analysis of conditional probabilities of electron density distribution for electron 1 with the reference electron fixed in a certain point 2. It is demonstrated that from the point of view of the mutual coupling of electron motions, the effective pairs behave analogously to singlet pairs. Based on this finding, effective pairs can be interpreted as the fraction of singlet pairs that is directly involved in bonding.

CONFINEMENT AND QUARK STRUCTURE OF LIGHT HADRONS

1989 ◽  
Vol 04 (08) ◽  
pp. 2031-2060 ◽  
Author(s):  
G. V. EFIMOV ◽  
M. A. IVANOV
Keyword(s):  
Weak Interactions ◽  
Point Of View ◽  
Low Energy ◽  
Unique Point ◽  
Quark Confinement ◽  
Quark Structure ◽  
Energy Physics ◽  
Confinement Model

We present a quark confinement model (QCM) for the description of the low energy physics of light hadrons (meson and baryons). The model is based on two hypotheses. First, the quark confinement is realized as averaging over some vacuum gluon fields which are believed to provide the confinement of any color objects. Second, hadrons are treated as collective colorless excitations of quark-gluon interactions. The description of strong, electromagnetic and weak interactions of mesons and baryons at the low energy is given from a unique point of view.

Modal Ethos

2017 ◽  
pp. 291-308
Author(s):  
Jonathan S. Carter
Keyword(s):  
Modal Analysis ◽  
Point Of View ◽  
Media Ecology ◽  
Political Judgment ◽  
Unique Point ◽  
Narrative History ◽  
The Individual ◽  
Ukraine Crisis

Traditionally, the artistic proofs center on the individual rhetor as the locusof ethos. However, as communication becomes internetworked, rhetorical phenomena increasingly circulate independent of traditional rhetors. This absence transfers ethos onto textual assemblages that often function as agents in their own right. This transfer of ethos is particularly apparent in memes, where fragmented images constructed across divergent networked media come together to form a single agentic text. Therefore, this chapter argues that a theory of modal ethos is important to understand this artistic proof's role in a networked media ecology. Through a modal analysis of the meme Scumbag Steve, this chapter argues that the modal construction of the meme gives it a unique point of view, complete with narrative history, affective representation, and social expertise—in short, its very own ethos. This allows networked participants to evoke the meme in controversies ranging from NSA wiretapping to the Ukraine Crisis, demanding new forms of political judgment.

scholarly journals Heterogeneous materials: metastable and non-ergodic internal structures

2019 ◽  
Vol 377 (2143) ◽  
pp. 20180353 ◽  
Author(s):  
Dmitri V. Alexandrov ◽  
Andrey Yu. Zubarev
Keyword(s):  
Magnetic Fields ◽  
Heterogeneous Media ◽  
Heterogeneous Materials ◽  
Computer Methods ◽  
Atomistic Modelling ◽  
Internal Structures ◽  
Long Time ◽  
Biological Polymers ◽  
Physical Mechanics ◽  
Non Equilibrium

This issue is concerned with structural and phase transitions in heterogeneous and composite materials, the effects of external magnetic fields on these phenomena and the macroscopic properties and behaviour of materials with isotropic and anisotropic internal structures. Using experimental, theoretical and computer methods, these transitions are studied at the atomic and mesoscopic levels. The fundamental specific feature of structural transitions in many heterogeneous media consists of the fact that these transitions are stacked for a long time in non-equilibrium states that appear due to either macroscopic dissipative processes (an alternating magnetic field or hydrodynamic flow, for instance) or system lifetime in a metastable state. It is important to explain and describe these transitional states using the general approach of non-equilibrium physical mechanics. The review and research articles in the issue will cover the whole spectrum of scales (from nano to macro) and materials (from metastable liquids to biological polymers) in order to exhibit recently developed trends in the field of heterogeneous materials. Atomistic modelling, structuring induced by external magnetic fields and hydrodynamic flows, metastable and non-ergodic states, mechanical properties and phenomena in heterogeneous materials—all these are covered. This article is part of the theme issue ‘Heterogeneous materials: metastable and non-ergodic internal structures’.

A Survey of Models of Ultraslow Diffusion in Heterogeneous Materials

2019 ◽  
Vol 71 (4) ◽  
Author(s):  
Yingjie Liang ◽  
Shuhong Wang ◽  
Wen Chen ◽  
Zhifang Zhou ◽  
Richard L. Magin
Keyword(s):  
Process Model ◽  
Heterogeneous Media ◽  
Heterogeneous Materials ◽  
Aging Effect ◽  
Macroscopic Models ◽  
Ergodic Properties ◽  
Velocity Autocorrelation ◽  
Mechanical Models ◽  
Many Body Systems ◽  
Distributed Order

Ultraslow diffusion is characterized by a logarithmic growth of the mean squared displacement (MSD) as a function of time. It occurs in complex arrangements of molecules, microbes, and many-body systems. This paper reviews mechanical models for ultraslow diffusion in heterogeneous media from both macroscopic and microscopic perspectives. Macroscopic models are typically formulated in terms of a diffusion equation that employs noninteger order derivatives (distributed order, structural, and comb models (CM)) or employs a diffusion coefficient that is a function of space or time. Microscopic models are usually based on the continuous time random walk (CTRW) theory, but use a weighted logarithmic function as the limiting formula of the waiting time density. The similarities and differences between these models are analyzed and compared with each other. The corresponding MSD in each case is tabulated and discussed from the perspectives of the underlying assumptions and of real-world applications in heterogeneous materials. It is noted that the CMs can be considered as a type of two-dimensional distributed order fractional derivative model (DFDM), and that the structural derivative models (SDMs) generalize the DFDMs. The heterogeneous diffusion process model (HDPM) with time-dependent diffusivity can be rewritten to a local structural derivative diffusion model mathematically. The ergodic properties, aging effect, and velocity autocorrelation for the ultraslow diffusion models are also briefly discussed.

Formulas for Entraining Velocity in Lubricated Line Contacts

2002 ◽  
Vol 124 (4) ◽  
pp. 856-858
Author(s):  
Enrico Ciulli
Keyword(s):  
Relative Motion ◽  
Physical Meaning ◽  
Point Of View ◽  
Lubricated Contacts ◽  
Line Contacts ◽  
Two Bodies

The knowledge of the entraining velocity is necessary for the investigation of lubricated contacts. The entraining velocity is the average of the surface velocities of the two bodies in contact relative to the contact itself; its estimation can be actually not always immediate. In this work the general case of two pairing cylindrical surfaces in planar relative motion is analyzed from a kinematical point of view. Formulas for the evaluation of the entraining velocity are presented that are directly applicable to any case of connected members of a mechanism. The physical meaning of the terms of the proposed formulas is also briefly investigated from a lubrication point of view.

scholarly journals Electron diffraction on a traveling wave: “Inelastic Kapitza–Dirac effect”

2016 ◽  
Vol 34 (3) ◽  
pp. 480-492 ◽  
Author(s):  
H. K. Avetissian
Keyword(s):  
Electromagnetic Wave ◽  
Electron Diffraction ◽  
Traveling Wave ◽  
Review Paper ◽  
Scientific Literature ◽  
Dielectric Medium ◽  
Point Of View ◽  
Diffraction Effect ◽  
Chronological Order ◽  
Diffraction Effects

AbstractIn this paper, conceptual points regarding electron elastic (Kapitza–Dirac effect) and inelastic diffraction effects on the slowed electromagnetic wave-structures/light-gratings are considered. From the unified point of view it is analyzed the main works on this subject for last four decades in chronological order, pointing out the essential peculiarity inherent in induced Cherenkov, Compton, and undulator/wiggler processes too. This review paper has also purpose to resolve confusion in scientific literature connected with the recently appeared paper Hayrapetyan et al. in 2015 regarding electron diffraction effect on a traveling wave in a dielectric medium.

scholarly journals The Complex Order Fractional Derivatives and Systems Are Non Hermitian

2021 ◽  
Author(s):  
Manuel Ortigueira
Keyword(s):  
Fractional Derivative ◽  
Fractional Derivatives ◽  
Point Of View ◽  
Logarithmic Phase ◽  
Complex Order ◽  
Application Point ◽  
Allpass Filters

This paper discusses the concept of fractional derivative with complex order from the application point of view. It is shown that a fractional derivative is hermitian, if and only if the order is real. The hermitian part of complex order derivatives behave like allpass filters with almost logarithmic phase.

scholarly journals Square of Brownian motion

1975 ◽  
Vol 59 ◽  
pp. 1-8
Author(s):  
Hisao Nomoto
Keyword(s):  
Stochastic Process ◽  
Brownian Motion ◽  
Correlation Function ◽  
Finite Time ◽  
Present Note ◽  
Point Of View ◽  
Time Interval ◽  
Sample Function ◽  
Finite Time Interval ◽  
Zero Crossings

Let Xt be a stochastic process and Yt be its square process. The present note is concerned with the solution of the equation assuming Yt is given. In [4], F. A. Grünbaum proved that certain statistics of Yt are enough to determine those of Xt when it is a centered, nonvanishing, Gaussian process with continuous correlation function. In connection with this result, we are interested in sample function-wise inference, though it is far from generalities. A glance of the equation shows that the difficulty is related how to pick up a sign of . Thus if we know that Xt has nice sample process such as the zero crossings are finite, no tangencies, in any finite time interval, then observations of these statistics will make it sure to find out sample functions of Xt from those of Yt (see [2]). The purpose of this note is to consider the above problem from this point of view.

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