Designing One-, Two-, and Three-Dimensional Left-Handed Materials

2017 ◽  
pp. 17-1-17-18
Author(s):  
Maria Kafesaki ◽  
Th. Koschny ◽  
C. M. Soukoulis ◽  
E. N. Economou
Keyword(s):  
Three Dimensional ◽  
Left Handed

A new model for packing of type-I collagen molecules in the native fibril

1981 ◽  
Vol 1 (10) ◽  
pp. 801-810 ◽  
Author(s):  
Karl A. Piez ◽  
Benes L. Trus
Keyword(s):  
Type I Collagen ◽  
Hexagonal Lattice ◽  
Three Dimensional ◽  
Equatorial Region ◽  
Type I ◽  
X Ray Diffraction ◽  
X Ray ◽  
Left Handed ◽  
Crystal Model ◽  
Collagen Molecules

A specific fibril model is presented consisting of bundles of five-stranded microfibrils, which are usually disordered (except axially) but under lateral compression become ordered. The features are as follows (where D = 234 residues or 67 nm): (1) D-staggered collagen molecules 4.5 D long in the helical microfibril have a left-handed supercoil with a pitch of 400–700 residues, but microfibrils need not have helical symmetry. (2) Straight-tilted 0.5-D overlap regions on a near-hexagonal lattice contribute the discrete x-ray diffraction reflections arising from lateral order, while the gap regions remain disordered. (3) The overlap regions are equivalent, but are crystallographically distinguished by systematic displacements from the near-hexagonal lattice. (4) The unit cell is the same as in a recently proposed three-dimensional crystal model, and calculated intensities in the equatorial region of the x-ray diffraction pattern agree with observed values.

A candidate three-dimensional GHz left-handed metamaterial composed of coplanar magnetic and electric resonators

2008 ◽  
Vol 6 (3-4) ◽  
pp. 183-187 ◽  
Author(s):  
J.F. Wang ◽  
Sh.B. Qu ◽  
Zh. Xu ◽  
J.Q. Zhang ◽  
Y.M. Yang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Left Handed

scholarly journals Transmural distribution of three-dimensional strain in the isolated arrested canine left ventricle

1991 ◽  
Vol 261 (3) ◽  
pp. H918-H928 ◽  
Author(s):  
J. H. Omens ◽  
K. D. May ◽  
A. D. McCulloch
Keyword(s):  
Three Dimensional ◽  
Left Ventricular Pressure ◽  
Ventricular Volume ◽  
Left Ventricular ◽  
Fiber Direction ◽  
Plane Shear ◽  
Left Handed ◽  
Longitudinal Strains ◽  
Transverse Shear Strains ◽  
Principal Strains

Three-dimensional myocardial strains in seven isolated, potassium-arrested dog hearts were measured by biplane radiography of 3 transmural columns of 4-6 radiopaque beads implanted in the midanterior left ventricular free wall. Transmural distributions of strain during inflation of a left ventricular balloon to 20-30 mmHg were computed with respect to the zero pressure state. Magnitudes of the 3 principal strains increased in proportion to ventricular volume (0.0088, 0.0037, and -0.0059 ml-1). At a left ventricular pressure of 8 +/- 4 mmHg, mean circumferential (E11) and longitudinal strains (E22) were similar, increasing from epicardium (0.058 +/- 0.055 and 0.036 +/- 0.024) to subendocardium (0.139 +/- 0.102 and 0.120 +/- 0.084) as did the transmural (wall thinning) strain E33 (-0.053 +/- 0.071 to -0.128 +/- 0.083). Negative in-plane shear E12 was small (-0.008 to -0.052), consistent with a left-handed torsion of the left ventricular wall. Mean transverse shear strains E13 and E23 were small (-0.029 to 0.007) but showed considerable variability between hearts. Fiber strain had no significant transmural variation (P = 0.57). The principal axis of greatest strain was close to the fiber orientation on the epicardium (-15 degrees) but closer to the cross-fiber direction near the endocardium (-40 degrees). Therefore, the end-diastolic fiber lengths are maximized on the epicardium and minimized on the endocardium.

scholarly journals Rotation and twist of the central-pair microtubules in the cilia of Paramecium.

1980 ◽  
Vol 87 (1) ◽  
pp. 33-46 ◽  
Author(s):  
C K Omoto ◽  
C Kung
Keyword(s):  
Thin Section ◽  
Three Dimensional ◽  
Ciliary Movement ◽  
High Voltage Electron Microscopy ◽  
Central Pair ◽  
Voltage Electron ◽  
University Of Wisconsin ◽  
Left Handed ◽  
Thin Section Analysis ◽  
Metachronal Waves

The orientation and configuration of the central-pair microtubules in cilia were studied by serial thin-section analysis of "instantaneously fixed" paramecia. Cilia were frozen in various positions in metachronal waves by such a fixation. The spatial sequence of these positions across the wave represents the temporal sequence of the positions during the active beat cycle of a cilium. Systematic shifts of central-pair orientation across the wave indicate that the central pair rotates 360 degrees counterclockwise (viewed from outside) with each ciliary beat cycle (C. K. Omoto, 1979, Thesis, University of Wisconsin, Madison; C. K. Omoto and C. Kung, 1979, Nature [Lond.] 279:532-534). This is true even for paramecia with different directions of effective stroke as in forward- or backward-swimming cells. The systematic shifts of central-pair orientation cannot be seen in Ni++-paralyzed cells or sluggish mutants which do not have metachronal waves. Both serial thin-section and thick-section high-voltage electron microscopy show that whenever a twist in the central pair is seen, it is always left-handed. This twist is consistent with the hypothesis that the central pair continuously rotates counterclockwise with the rotation originating at the base of the cilium. That the rotation of the central pair is most likely with respect to the peripheral tubules as well as the cell surface is discussed. These results are incorporated into a model in which the central-pair complex is a component in the regulation of the mechanism needed for three-dimensional ciliary movement.

Scanning Tunneling Microscopy Study of α,ω-Dihexylsexithiophene Adlayers on Au(111): A Chiral Separation Induced by a Surface

2012 ◽  
Vol 18 (4) ◽  
pp. 885-891 ◽  
Author(s):  
Yonghai Song ◽  
Yu Wang ◽  
Lingli Wan ◽  
Shuhong Ye ◽  
Haoqing Hou ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Self Assembly ◽  
Room Temperature ◽  
Three Dimensional ◽  
Microscopy Study ◽  
Molecular Structures ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Left Handed ◽  
Bulk Structure

AbstractThe self-assembly of α,ω-dihexylsexithiophene molecules on an Au(111) surface was examined by using scanning tunneling microscopy at room temperature, revealing the internal molecular structures of the sexithiophene backbones and the hexyl side chains. The α,ω-dihexylsexithiophene formed a large and well-ordered monolayer in which the molecule lay flatly on the Au(111) surface and was separated into two chiral domains. A detailed observation reveals that the admolecules were packed in one lamellae with their molecular axis aligned along the main axis of the Au(111) substrate with their hexyl chains deviated from ⟨110⟩ direction of the Au(111) substrate by 12 ± 0.5°. In contrast to the behavior in the three-dimensional bulk structure, flat-lying adsorption introduced molecular chirality: right- and left-handed molecules separate into domains of two different orientations, which are mirror symmetric with respect to the ⟨121⟩ direction of the Au(111) substrate. Details of the adlayer structure and the chiral self-assembly were discussed here.

scholarly journals Numerical study of three-dimensional isotropic left-handed metamaterials at visible frequencies

2011 ◽  
Vol 60 (4) ◽  
pp. 044101
Author(s):  
Gong Bo-Yi ◽  
Zhou Xin ◽  
Zhao Xiao-Peng
Keyword(s):  
Numerical Study ◽  
Three Dimensional ◽  
Left Handed

A broad-band three-dimensional isotropic left-handed metamaterial

2009 ◽  
Vol 42 (15) ◽  
pp. 155413 ◽  
Author(s):  
Jia Fu Wang ◽  
Shao Bo Qu ◽  
Zhuo Xu ◽  
Zhen Tang Fu ◽  
Hua Ma ◽  
...  
Keyword(s):  
Broad Band ◽  
Three Dimensional ◽  
Left Handed

Incommensurately modulated ordering of tetrahedral chains in Ca2Fe2O5 at elevated temperatures

2005 ◽  
Vol 61 (6) ◽  
pp. 656-662 ◽  
Author(s):  
Hannes Krüger ◽  
Volker Kahlenberg
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Elevated Temperatures ◽  
Three Dimensional ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Modulated Structure ◽  
X Ray ◽  
Left Handed ◽  
Lattice Periodicity

The basic building units of brownmillerite-type A 2 B 2O5 structures are perovskite-like layers of corner-sharing BO6 octahedra and zweier single chains of BO4 tetrahedra. A three-dimensional framework is formed by alternate stacking of octahedral layers and sheets of tetrahedral chains. The compound Ca2Fe2O5 is known to have Pnma symmetry at ambient conditions. The space group Imma was reported to be evident above 963 K. New high-temperature single-crystal X-ray diffraction experiments at 1100 K revealed that Ca2Fe2O5 forms an incommensurately modulated structure adopting the superspace group Imma(00γ)s00, with γ = 0.588 (2). The modulation affects the sequence of the enantiomorphic (right- and left-handed) oriented tetrahedral chains within the layer, breaking the lattice periodicity along c. This ordering can be modelled with crenel occupation modulation functions for the tetrahedrally coordinated Fe, as well as for the O atom interconnecting the tetrahedra.

The wave structure of monochromatic electromagnetic radiation

1987 ◽  
Vol 409 (1836) ◽  
pp. 21-36 ◽  
Keyword(s):  
Electromagnetic Radiation ◽  
Electromagnetic Waves ◽  
Plane Waves ◽  
Three Dimensional ◽  
Wave Structure ◽  
Single Frequency ◽  
Singularity Index ◽  
Left Handed ◽  
General Field ◽  
Structurally Stable

The paper considers a general field of electromagnetic waves of a single frequency and identifies the salient structurally stable features of the three-dimensional pattern of polarization. The approach is geometrical rather than analytical, and it differs from previous treatments of this kind by being applicable even when the constituent plane waves are travelling in all directions. Lines and surfaces exist where the electric or magnetic vibration ellipse is singular. The field is divided into right-handed and left-handed regions by ‘T surfaces’ , the electric and magnetic T surfaces not being coincident. Lying in the T surfaces are ‘L T lines’ where the vibration is linear, and cutting through the T surfaces are ‘C T lines’ where the vibration is circular. Both kinds of lines are surrounded by characteristic patterns of vibration ellipses, which provide a singularity index, ± 1 for L T and ± ½ for C T . The analysis is applicable in a cavity, but a loss-free resonating cavity represents a highly degenerate case.

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