71 research outputs found
Origem das artĂŠrias dos nĂłs sinoatrial e atrioventricular em população do sul da Ăndia: um estudo angiogrĂĄfico
Radiative and non-radiative local density of states on disordered plasmonic films
We present numerical calculations of the Local Density of Optical States
(LDOS) in the near field of disordered plasmonic films. The calculations are
based on an integral volume method, that takes into account polarization and
retardation effects, and allows us to discriminate radiative and non-radiative
contributions to the LDOS. At short distance, the LDOS is dominated by
non-radiative channels, showing that changes in the spontaneous dynamics of
dipole emitters are driven by non-radiative coupling to plasmon modes. Maps of
radiative and non-radiative LDOS exhibit strong fluctuations, but with
substantially different spatial distributions
A rigorous analysis of high order electromagnetic invisibility cloaks
There is currently a great deal of interest in the invisibility cloaks
recently proposed by Pendry et al. that are based in the transformation
approach. They obtained their results using first order transformations. In
recent papers Hendi et al. and Cai et al. considered invisibility cloaks with
high order transformations. In this paper we study high order electromagnetic
invisibility cloaks in transformation media obtained by high order
transformations from general anisotropic media. We consider the case where
there is a finite number of spherical cloaks located in different points in
space. We prove that for any incident plane wave, at any frequency, the
scattered wave is identically zero. We also consider the scattering of finite
energy wave packets. We prove that the scattering matrix is the identity, i.e.,
that for any incoming wave packet the outgoing wave packet is the same as the
incoming one. This proves that the invisibility cloaks can not be detected in
any scattering experiment with electromagnetic waves in high order
transformation media, and in particular in the first order transformation media
of Pendry et al. We also prove that the high order invisibility cloaks, as well
as the first order ones, cloak passive and active devices. The cloaked objects
completely decouple from the exterior. Actually, the cloaking outside is
independent of what is inside the cloaked objects. The electromagnetic waves
inside the cloaked objects can not leave the concealed regions and viceversa,
the electromagnetic waves outside the cloaked objects can not go inside the
concealed regions. As we prove our results for media that are obtained by
transformation from general anisotropic materials, we prove that it is possible
to cloak objects inside general crystals.Comment: The final version is now published in Journal of Physics A:
Mathematical and Theoretical, vol 41 (2008) 065207 (21 pp). Included in
IOP-Selec
The Boundary Conditions for Point Transformed Electromagnetic Invisibility Cloaks
In this paper we study point transformed electromagnetic invisibility cloaks
in transformation media that are obtained by transformation from general
anisotropic media. We assume that there are several cloaks located in different
points in space. Our results apply in particular to the first order
invisibility cloaks introduced by Pendry et al. and to the high order
invisibility cloaks introduced by Hendi et al. and by Cai et al.. We identify
the appropriate {\it cloaking boundary conditions} that the solutions of
Maxwell equations have to satisfy at the outside, , and at the
inside, , of the boundary of the cloaked object . Namely, that
the tangential components of the electric and the magnetic fields have to
vanish at -what is always true- and that the normal components
of the curl of the electric and the magnetic fields have to vanish at . These results are proven requiring that energy be conserved. In the case
of one spherical cloak with a spherically stratified and a radial current
at we verify by an explicit calculation that our {\it cloaking
boundary conditions} are satisfied and that cloaking of active devices holds
even if the current is at the boundary of the cloaked object. As we prove our
results for media that are obtained by transformation from general anisotropic
media, our results apply to the cloaking of objects with active and passive
devices contained in general anisotropic media, in particular to objects with
active and passive devices contained inside general crystals.Comment: This final, published, version has been edited, comments have been
adde
Track D Social Science, Human Rights and Political Science
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138414/1/jia218442.pd
The Anterior Transverse Ligament of Knee: Morphological and Morphometric Study in Formalin Fixed Human Fetuses.
The objective was to study the morphology and morphometry of transverse ligament of the knee joint in south Indian population. The present study included 53 formalin fixed foetuses which were obtained from the department of Anatomy. There were 106 knee joints which were available for the present study. A vernier caliper of 0.02 mm accuracy was used to measure the length of the transverse ligament. Among our specimens, transverse ligament of the knee was observed in 87.7% of the cases. It was observed bilaterally in 81.1% of cases. The double transverse ligaments were not observed in any of our specimens. The mean length of the transverse ligament measured 3.7 Âą 1.5 mm. The statistically significant difference was not observed between the right and left sided transverse ligaments or gender with regard to its length (Student's t test; p > 0.05). The morphological and morphometric data related to the transverse ligament of the knee in human foetuses have not been reported. The present study provides additional information on the morphology and morphometry of the transverse ligament in human foetuses. We believe that the data of the present study will provide support to the foetal anatomy, concerning the surgical procedures and arthroscopy of the knee joint. The findings are enlightening not only for Orthopedic Surgeons, but also for the Morphologists and Embryologists
Fabrication and realistic modeling of three-dimensional metal-dielectric composites
Historically, the methods used to describe the electromagnetic response of random, three-dimensional (3D), metal-dielectric composites (MDCs) have been limited to approximations such as effective-medium theories that employ easily-obtained, macroscopic parameters. Full-wave numerical simulations such as finite-difference time domain (FDTD) calculations are difficult for random MDCs due to the fact that the nanoscale geometry of a random composite is generally difficult to ascertain after fabrication. We have developed a fabrication method for creating semicontinuous metal films with arbitrary thicknesses and a modeling technique for such films using realistic geometries. We extended our two-dimensional simulation method to obtain realistic geometries of 3D MDC samples, and we obtained the detailed near-and far-field electromagnetic responses of such composites using FDTD calculations. Our simulation results agree quantitatively well with the experimentally measured far-field spectra of the real samples. (C) 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.3590208
Origem das artĂŠrias dos nĂłs sinoatrial e atrioventricular em população do sul da Ăndia: um estudo angiogrĂĄfico
FUNDAMENTO: Estudar o suprimento arterial do sistema condutor e sua correlação com a dominância das artĂŠrias coronĂĄrias em população do sul da Ăndia. OBJETIVO: Determinar angiograficamente as origens da artĂŠria do nĂł sinoatrial (AnSA) e artĂŠria do nĂł atrioventricular (AnAV) em indianos. MĂTODOS: O ESTudo incluiu 300 pacientes consecutivos (114 do sexo feminino e 186 do sexo masculino; idade mĂŠdia, 55 anos), habitantes da regiĂŁo costeira ao sul da Ăndia, submetidos a cineangiocoronariografia devido a sintomas como dor no peito, angina pectoris ou teste ergomĂŠtrico positivo. As angiografias incluĂram ambas as artĂŠrias coronĂĄrias (direita e esquerda) em posição oblĂqua anterior direita e esquerda. A origem da AnSA e AnAV a partir das artĂŠrias coronĂĄrias foi observada e correlacionada Ă dominância arterial. RESULTADOS: O nĂł SA (sinoatrial) recebeu suprimento pela artĂŠria coronĂĄria direita (ACD) em 53% dos casos, pelo ramo circunflexo (Cx) da artĂŠria coronĂĄria esquerda (ACE) em 42,66% dos casos, e em 4,33% dos casos esse nĂł foi irrigado por ambas as artĂŠrias coronĂĄrias. O nĂł AV (atrioventricular) tambĂŠm recebeu suprimento sanguĂneo com mais frequĂŞncia da ACD (72,33% dos casos) do que do ramo Cx da ACE (27,66%). Surpreendentemente, em nenhum caso este nĂł recebeu suprimento de ambas as artĂŠrias coronĂĄrias. CONCLUSĂO: Os Resultados do presente estudo podem auxiliar os cirurgiĂľes cardĂacos, sobretudo em cirurgias relacionadas a valvopatias, devido Ă franca proximidade entre os ramos nodais e o complexo valvar
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