scholarly journals Two non-identical twins in one unit cell: characterization of 34π aromatic core-modified octaphyrins, their structural isomers and anion bound complexes

2019 ◽  
Vol 10 (23) ◽  
pp. 5911-5919 ◽  
Author(s):  
Arindam Ghosh ◽  
Syamasrit Dash ◽  
A. Srinivasan ◽  
Cherumuttathu H. Suresh ◽  
Tavarekere K. Chandrashekar

Two inseparable isomers A and B (non-identical twins) crystallize in a single unit cell. However, replacement of middle thiophene ring by selenophene ring results in crystallization of two molecules of isomer A (identical twins).

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Ladislau Matekovits ◽  
Karu P. Esselle ◽  
Mirko Bercigli ◽  
Rodolfo Guidi

Application of the synthetic function expansion (SFX) algorithm to the analysis of active 1- and 2D periodic structures is presented. The single unit cell consisting of a microstrip line loaded by patches positioned below the line is turned into an active structure by inserting a pair of 2 switches to the two ends of each patch; the states of the pair of switches are changed contemporaneously. Variation of the states of the switches modifies the current distribution on the structure. The tunable multistate unit cell is arranged in 24-, 120-, and 9 × 24 element configurations and numerically analyzed. The computational complexity required for the characterization of the large number of possible configurations is lightened by the use of the proposed numerical method.


Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1259
Author(s):  
Dmitry Kozlov ◽  
Irina Munina ◽  
Pavel Turalchuk ◽  
Vitalii Kirillov ◽  
Alexey Shitvov ◽  
...  

A new implementation of a beam-steering transmitarray is proposed based on the tiled array architecture. Each pixel of the transmitarray is manufactured as a standalone unit which can be hard-wired for specific transmission characteristics. A set of complementary units, providing reciprocal phase-shifts, can be assembled in a prescribed spatial phase-modulation pattern to perform beam steering and beam forming in a broad spatial range. A compact circuit model of the tiled unit cell is proposed and characterized with full-wave electromagnetic simulations. Waveguide measurements of a prototype unit cell have been carried out. A design example of a tiled 10 × 10-element 1-bit beam-steering transmitarray is presented and its performance benchmarked against the conventional single-panel, i.e., unibody, counterpart. Prototypes of the tiled and single-panel C-band transmitarrays have been fabricated and tested, demonstrating their close performance, good agreement with simulations and a weak effect of fabrication tolerances. The proposed transmitarray antenna configuration has great potential for fifth-generation (5G) communication systems.


Author(s):  
T. O. M. Forslund ◽  
I. A. S. Larsson ◽  
J. G. I. Hellström ◽  
T. S. Lundström

AbstractThe effects of periodicity assumptions on the macroscopic properties of packed porous beds are evaluated using a cascaded Lattice-Boltzmann method model. The porous bed is modelled as cubic and staggered packings of mono-radii circular obstructions where the bed porosity is varied by altering the circle radii. The results for the macroscopic properties are validated using previously published results. For unsteady flows, it is found that one unit cell is not enough to represent all structures of the fluid flow which substantially impacts the permeability and dispersive properties of the porous bed. In the steady region, a single unit cell is shown to accurately represent the fluid flow across all cases studied


ACS Nano ◽  
2021 ◽  
Author(s):  
Azmira Jannat ◽  
Nitu Syed ◽  
Kai Xu ◽  
Md. Ataur Rahman ◽  
Md. Mehdi Masud Talukder ◽  
...  

Author(s):  
Tracey Freeman ◽  
Christina Andreou ◽  
Robert P. Sebra ◽  
Kristin G. Beaumont ◽  
Talia H. Swartz

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