scholarly journals Numerical analysis of plasmonic metasurfaces for fluorescence enhancement

2021 ◽  
Vol 255 ◽  
pp. 04004
Author(s):  
Roxana Tomescu ◽  
Florin Nita ◽  
Stefan Caramizoiu ◽  
Veronica Anastasoaie ◽  
Dana Cristea

The paper presents an extensive numerical analysis performed by three-dimensional (3D) simulations using the finite difference in time and space (FDTD) method to identify the optimal geometry, size and configuration of the nano-antennas that constitute a plasmonic metasurface. The aim was to achieve the highest resonance at various wavelengths (NIR-VIS), for local enhancement of the excitation field and collection efficiency of emitted photons. We investigated ten different types of metals, two shapes (disks and U-shape resonators) and various geometrical parameters for the nanoresonators composing the metasurface. The best results for Rhodamine 6G excitation and emission were obtained using silver resonators with 105 nm diameter of the cylinder elements in a rectangular array with a 110 nm period, and with 110 nm long U-shape placed at a period of 40 nm.

2018 ◽  
Vol 32 (31) ◽  
pp. 1850344 ◽  
Author(s):  
N. Eti ◽  
Z. Çetin ◽  
H. S. Sözüer

A detailed numerical study of low-loss silicon on insulator (SOI) waveguide bend is presented using the fully three-dimensional (3D) finite-difference time-domain (FDTD) method. The geometrical parameters are optimized to minimize the bending loss over a range of frequencies. Transmission results for the conventional single bend and photonic crystal assisted SOI waveguide bend are compared. Calculations are performed for the transmission values of TE-like modes where the electric field is strongly transverse to the direction of propagation. The best obtained transmission is over 95% for TE-like modes.


2012 ◽  
Vol 433-440 ◽  
pp. 2377-2386
Author(s):  
Wen Yeuan Chung

The 3D and 2D type maps for planar four-bar and simply RSSR linkages are constructed with illustration of their application. The criteria determining the rotatability of input or output link are developed or reviewed for both linkages. Three-dimensional type maps are then constructed by integrating the tool for numerical analysis and solid modeling software, e.g. MATLAB and PRO/E. The coordinate axes are mainly three ratios of link lengths. The types are classified based on whether the input or output link can make fully rotation. Each type map is composed of five regions representing different types. They are drag link, crank-rocker, rocker-crank, double-rocker, and unassembled. Any cross sections can be taken readily and arbitrarily from the 3D models along any plane or surfaces to get 2D type maps. The constructed type maps are also combined with curves or surfaces representing performances of transmission ratio. With type maps and related surfaces, the design process can be simplified and expedited substantially.


2018 ◽  
Vol 18 ◽  
pp. 38 ◽  
Author(s):  
Michaela Neuhäuserová ◽  
Petr Koudelka

The paper is focused on numerical analysis of mechanical behaviour of auxetic structures with re-entrant tetrakaidecahedral unit cell subjected to uni-axial quasi-static compression. The mechanical behaviour was evaluated inversely with respect to selected geometrical parameters of the unit cell and two different loading modes. Finite element method was used for the numerical analysis of the problem. A set of fully parametric tools has been developed, which enabled automated execution and evaluation of virtual experiments. From results of the simulations, Young’s modulus, the characteristics of the Poisson’s ratio function, and the deformation energy density were estimated. The relation between these characteristics and geometry of the unit cell, particularly the re-entrant angle and the relative density, was evaluated. Results of the numerical simulations for the unit cell and representative volume element of its three-dimensional periodic assembly are presented.


Author(s):  
P.L. Moore

Previous freeze fracture results on the intact giant, amoeba Chaos carolinensis indicated the presence of a fibrillar arrangement of filaments within the cytoplasm. A complete interpretation of the three dimensional ultrastructure of these structures, and their possible role in amoeboid movement was not possible, since comparable results could not be obtained with conventional fixation of intact amoebae. Progress in interpreting the freeze fracture images of amoebae required a more thorough understanding of the different types of filaments present in amoebae, and of the ways in which they could be organized while remaining functional.The recent development of a calcium sensitive, demembranated, amoeboid model of Chaos carolinensis has made it possible to achieve a better understanding of such functional arrangements of amoeboid filaments. In these models the motility of demembranated cytoplasm can be controlled in vitro, and the chemical conditions necessary for contractility, and cytoplasmic streaming can be investigated. It is clear from these studies that “fibrils” exist in amoeboid models, and that they are capable of contracting along their length under conditions similar to those which cause contraction in vertebrate muscles.


2016 ◽  
Vol E99.C (7) ◽  
pp. 817-819 ◽  
Author(s):  
Jun SHIBAYAMA ◽  
Yusuke WADA ◽  
Junji YAMAUCHI ◽  
Hisamatsu NAKANO

2019 ◽  
Vol 63 (5) ◽  
pp. 50402-1-50402-9 ◽  
Author(s):  
Ing-Jr Ding ◽  
Chong-Min Ruan

Abstract The acoustic-based automatic speech recognition (ASR) technique has been a matured technique and widely seen to be used in numerous applications. However, acoustic-based ASR will not maintain a standard performance for the disabled group with an abnormal face, that is atypical eye or mouth geometrical characteristics. For governing this problem, this article develops a three-dimensional (3D) sensor lip image based pronunciation recognition system where the 3D sensor is efficiently used to acquire the action variations of the lip shapes of the pronunciation action from a speaker. In this work, two different types of 3D lip features for pronunciation recognition are presented, 3D-(x, y, z) coordinate lip feature and 3D geometry lip feature parameters. For the 3D-(x, y, z) coordinate lip feature design, 18 location points, each of which has 3D-sized coordinates, around the outer and inner lips are properly defined. In the design of 3D geometry lip features, eight types of features considering the geometrical space characteristics of the inner lip are developed. In addition, feature fusion to combine both 3D-(x, y, z) coordinate and 3D geometry lip features is further considered. The presented 3D sensor lip image based feature evaluated the performance and effectiveness using the principal component analysis based classification calculation approach. Experimental results on pronunciation recognition of two different datasets, Mandarin syllables and Mandarin phrases, demonstrate the competitive performance of the presented 3D sensor lip image based pronunciation recognition system.


2020 ◽  
Vol 29 (4) ◽  
pp. 741-757
Author(s):  
Kateryna Hazdiuk ◽  
◽  
Volodymyr Zhikharevich ◽  
Serhiy Ostapov ◽  
◽  
...  

This paper deals with the issue of model construction of the self-regeneration and self-replication processes using movable cellular automata (MCAs). The rules of cellular automaton (CA) interactions are found according to the concept of equilibrium neighborhood. The method is implemented by establishing these rules between different types of cellular automata (CAs). Several models for two- and three-dimensional cases are described, which depict both stable and unstable structures. As a result, computer models imitating such natural phenomena as self-replication and self-regeneration are obtained and graphically presented.


Author(s):  
Matthew J. Genge

Drawings, illustrations, and field sketches play an important role in Earth Science since they are used to record field observations, develop interpretations, and communicate results in reports and scientific publications. Drawing geology in the field furthermore facilitates observation and maximizes the value of fieldwork. Every geologist, whether a student, academic, professional, or amateur enthusiast, will benefit from the ability to draw geological features accurately. This book describes how and what to draw in geology. Essential drawing techniques, together with practical advice in creating high quality diagrams, are described the opening chapters. How to draw different types of geology, including faults, folds, metamorphic rocks, sedimentary rocks, igneous rocks, and fossils, are the subjects of separate chapters, and include descriptions of what are the important features to draw and describe. Different types of sketch, such as drawings of three-dimensional outcrops, landscapes, thin-sections, and hand-specimens of rocks, crystals, and minerals, are discussed. The methods used to create technical diagrams such as geological maps and cross-sections are also covered. Finally, modern techniques in the acquisition and recording of field data, including photogrammetry and aerial surveys, and digital methods of illustration, are the subject of the final chapter of the book. Throughout, worked examples of field sketches and illustrations are provided as well as descriptions of the common mistakes to be avoided.


Author(s):  
Emre Bulut ◽  
Gökhan Sevilgen ◽  
Ferdi Eşiyok ◽  
Ferruh Öztürk ◽  
Tuğçe Turan Abi

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