scholarly journals EM Duality and Quasinormal Modes from Higher Derivatives with Homogeneous Disorder

2019 ◽  
Vol 2019 ◽  
pp. 1-19
Author(s):  
Guoyang Fu ◽  
Jian-Pin Wu
Keyword(s):  
Coupling Parameter ◽  
Quasinormal Modes ◽  
Imaginary Frequency ◽  
Higher Derivatives ◽  
Branch Cuts ◽  
Frequency Axis ◽  
Better Than

We study the electromagnetic (EM) duality from 6 derivative theory with homogeneous disorder. We find that, with the change of the sign of the coupling parameter γ1 of the 6 derivative theory, the particle-vortex duality with homogeneous disorder holds better than that without homogeneous disorder. The properties of quasinormal modes (QNMs) of this system are also explored. When the homogeneous disorder is introduced, some modes emerge at the imaginary frequency axis for negative γ1 but not for positive γ1. In particular, with an increase in the magnitude of α^, new branch cuts emerge for positive γ1. These emerging modes violate the duality related to the change of the sign of γ1. With the increase of α^, this duality is getting violated more.

scholarly journals Pengaturan Lampu Lalu Lintas dengan Simulasi Monte Carlo Studi Kasus : Perempatan Daerah Dago � Bandung

2016 ◽  
Vol 2 (2) ◽  
Author(s):  
Iryanto Iryanto ◽  
Dinan Andiwijayakusuma
Keyword(s):  
Monte Carlo ◽  
Coupling Parameter ◽  
Heavy Traffic ◽  
Traffic Light ◽  
Traffic Condition ◽  
Rule Based ◽  
Main Road ◽  
Traffic Jam ◽  
The Road ◽  
Better Than

One of the areas that often become a source of traffic jam is road intersection. So it will be crucial to manage the intersection. Every intersection in main road is common to have traffic light and every cycle of the lamp, red, green and orange, will influence the traffic. The traffic cycle will have significant role to decrease or increase effects of the problem. Inappropriate regulation for the intersection can cause traffic jam or a heavy traffic jam in the road. Sometimes every intersection needs different rule based on the traffic condition. Therefore is truly needed to manage the traffic light in every intersection. With the simulation we can know whether the rule for the traffic light has appropriated to the intersection's traffic condition. If the rule is not optimal yet, we can change the rule with the optimal one. In the research, two methods are used, using coupling parameter and without coupling parameter. Average of vehicle Arrival in each intersection is used as coupling parameter. As its result, using coupling parameter is better than without using coupling parameter.

COMPUTATIONAL CONSIDERATIONS IN THE CALCULATION OF THE CASIMIR FORCE BETWEEN MULTILAYERED SYSTEMS

2004 ◽  
Vol 19 (24) ◽  
pp. 4069-4084 ◽  
Author(s):  
FABRIZIO PINTO
Keyword(s):  
Casimir Force ◽  
Imaginary Frequency ◽  
Multilayered Systems ◽  
Multilayer Stacks ◽  
Gap Width ◽  
Multiple Poles ◽  
Frequency Axis

It is shown that, in contrast to the case of two semi-infinite slabs, the Casimir force between two periodic multilayer stacks cannot be computed by means of the typical Lifshitz integration along the imaginary frequency axis because both the integrand and the reflectivity coefficients display multiple poles on such axis. Consequently, all objections to the possibility of radically engineering the magnitude, gap width dependence, and sign of the Casimir force, which were based upon such invalid expressions, are removed. Some experimental and computational implications of these results are discussed.

Corrections to Kramers Formula Describing the Decay Rate of a Metastable State

2016 ◽  
Vol 685 ◽  
pp. 128-132
Author(s):  
N.E. Aktaev ◽  
K.A. Bannova
Keyword(s):  
Decay Rate ◽  
Metastable State ◽  
Langevin Equation ◽  
Approximate Formula ◽  
Dynamical Modeling ◽  
Higher Derivatives ◽  
Derivatives Of ◽  
Better Than

The work investigates the accuracy of the Kramers approximate formula describing the decay rate of a metastable state. The study was performed by comparing the rate obtained through Kramers formula with the quasistationary rate derived by dynamical modeling that was performed by solving the Langevin equation. We have demonstrated that the non-correlation between Kramers rate and dynamical rate reached 15%, while a better correlation was expected. The study allowed us to generate corrections to Kramers formula by accounting for the higher derivatives of the potential. The rate obtained by the corrected formula exhibits the correlation with the dynamic rate of better than 1%.

Response of a Helix Made of a Fractional Viscoelastic Material

2008 ◽  
Vol 75 (1) ◽  
Author(s):  
M. Ostoja-Starzewski ◽  
H. Shahsavari
Keyword(s):  
Fractional Order ◽  
Viscoelastic Material ◽  
Order Model ◽  
Effective Response ◽  
Integer Order ◽  
Torsional Response ◽  
Fractional Order Model ◽  
Higher Derivatives ◽  
Better Than ◽  
Helical Strand

Under investigation is the effective response of a helical strand (helix) made of a viscoelastic material governed by a constitutive relation with fractional-order (i.e., not integer-order) derivatives. The relation involves a 5-parameter model, which is well known to represent a real response much better than the conventional, integer-order models with the same number of parameters. We employ the correspondence principle of viscoelasticity to pass from the level of the strand’s material to that of an effective, coupled axial-torsional response of the helix. The resulting fractional-order differential equation is more complex (i.e., it involves higher derivatives) than the constitutive equation governing the material per se. Also, the use of a fractional-order model results in more complexity of the helix’ effective viscoelastic response than does an integer-order model with the same number of parameters. It is shown that shear deformations are more important than dilatational deformations. Lastly, a standard relaxation test is studied and an analytic solution is derived.

scholarly journals Дисперсионные силы между металлической и диэлектрической пластинами, разделенными магнитной жидкостью

2019 ◽  
Vol 89 (9) ◽  
pp. 1337
Author(s):  
Е.Н. Величко ◽  
Г.Л. Климчицкая ◽  
В.М. Мостепаненко
Keyword(s):  
Dielectric Properties ◽  
Silica Glass ◽  
Room Temperature ◽  
Volume Fraction ◽  
Dispersion Forces ◽  
Imaginary Frequency ◽  
Analytic Expressions ◽  
Magnetite Particles ◽  
Theory Framework ◽  
Frequency Axis

The Lifshitz theory framework is applied to determine the pressure of dispersion forces between metallic and dielectric plates separated by a thin layer of ferrofluid. Numerical computations are performed for the plates made of gold and silica glass and ferrofluid consisting of kerosene and nanoparticles of magnetite at room temperature. For this purpose we have used familiar representations for the dielectric properties of gold and silica glass along the imaginary frequency axis and obtained respective representations for magnetite and kerosene. The pressure of dispersion forces was investigated as the function of separation between the plates, of the volume fraction of magnetite particles in a ferrofluid and of their diameter. At sufficiently large separations between the plates simple analytic expressions for this pressure are derived. We discuss possible applications of the obtained results.

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

Localization of immunolabels by electron microscopy and image averaging

1983 ◽  
Vol 41 ◽  
pp. 282-283
Author(s):  
J. Frank ◽  
P.-Y. Sizaret ◽  
A. Verschoor ◽  
J. Lamy
Keyword(s):  
Electron Microscopy ◽  
Single Particle ◽  
Attachment Site ◽  
Uranyl Acetate ◽  
Limulus Polyphemus ◽  
Resolution Limit ◽  
Electron Microscopic ◽  
Image Averaging ◽  
Top View ◽  
Better Than

The accuracy with which the attachment site of immunolabels bound to macromolecules may be localized in electron microscopic images can be considerably improved by using single particle averaging. The example studied in this work showed that the accuracy may be better than the resolution limit imposed by negative staining (∽2nm).The structure used for this demonstration was a halfmolecule of Limulus polyphemus (LP) hemocyanin, consisting of 24 subunits grouped into four hexamers. The top view of this structure was previously studied by image averaging and correspondence analysis. It was found to vary according to the flip or flop position of the molecule, and to the stain imbalance between diagonally opposed hexamers (“rocking effect”). These findings have recently been incorporated into a model of the full 8 × 6 molecule.LP hemocyanin contains eight different polypeptides, and antibodies specific for one, LP II, were used. Uranyl acetate was used as stain. A total of 58 molecule images (29 unlabelled, 29 labelled with antl-LPII Fab) showing the top view were digitized in the microdensitometer with a sampling distance of 50μ corresponding to 6.25nm.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

Electron Microscopic Observation of the Longitudinal Organization of Poly (p-Phenylene Terephthalamide) Fibers

1982 ◽  
Vol 40 ◽  
pp. 680-681
Author(s):  
Li Li-Sheng ◽  
L.F. Allard ◽  
W.C. Bigelow
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Microscopic Observation ◽  
Electron Microscopic Observation ◽  
Electron Microscopic ◽  
Aromatic Polyamides ◽  
Radial Arrangement ◽  
Scanning Electron ◽  
Better Than

The aromatic polyamides form a class of fibers having mechanical properties which are much better than those of aliphatic polyamides. Currently, the accepted morphology of these fibers as proposed by M.G. Dobb, et al. is a radial arrangement of pleated sheets, with the plane of the pleats parallel to the axis of the fiber. We have recently obtained evidence which supports a different morphology of this type of fiber, using ultramicrotomy and ion-thinning techniques to prepare specimens for transmission and scanning electron microscopy.

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