Impedance Analysis of Printed Antenna on Three-Dimensional High-Permittivity Dielectric Substrate Using Mixed-Domain MoM

2009 ◽  
Vol E92-B (6) ◽  
pp. 2352-2355
Author(s):  
Amin SAEEDFAR ◽  
Hiroyasu SATO ◽  
Kunio SAWAYA
Keyword(s):  
Three Dimensional ◽  
Impedance Analysis ◽  
Dielectric Substrate ◽  
Printed Antenna ◽  
High Permittivity

Quantitative Research on Cracks in Pipe Based on Magnetic Field Response Method of Eddy Current Testing

2021 ◽  
Vol 36 (1) ◽  
pp. 99-107
Author(s):  
Feng Jiang ◽  
Shulin Liu ◽  
Li Tao
Keyword(s):  
Magnetic Field ◽  
Eddy Current ◽  
Quantitative Research ◽  
Three Dimensional ◽  
Impedance Analysis ◽  
Eddy Current Testing ◽  
Element Analysis ◽  
Defect Parameter ◽  
Current Testing ◽  
The Magnetic Field

The quantitative evaluation of defects in eddy current testing is of great significance. Impedance analysis, as a traditional method, is adopted to determine defects in the conductor, however, it is not able to depict the shape, size and location of defects quantitatively. In order to obtain more obvious characteristic quantities and improve the ability of eddy current testing to detect defects, the study of cracks in metal pipes is carried out by utilizing the analysis method of three-dimensional magnetic field in present paper. The magnetic field components in the space near the crack are calculated numerically by using finite element analysis. The simulation results confirm that the monitoring of the crack change can be achieved by measuring the magnetic field at the arrangement positions. Besides, the quantitative relationships between the shape, length of the crack and the magnetic field components around the metal pipe are obtained. The results show that the axial and radial magnetic induction intensities are affected more significantly by the cross-section area of the crack. Bz demonstrates obvious advantages in analyzing quantitatively crack circumference length. Therefore, the response signal in the three-dimensional direction of the magnetic field gets to intuitively reflect the change of the defect parameter, which proves the effectiveness and practicability of this method.

scholarly journals Impedance Study of Dopamine Effects after Application on 2D and 3D Neuroblastoma Cell Cultures Developed on a 3D-Printed Well

Chemosensors ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 6 ◽  
Author(s):  
Georgia Paivana ◽  
Theofylaktos Apostolou ◽  
Sophie Mavrikou ◽  
Dimitris Barmpakos ◽  
Grigoris Kaltsas ◽  
...  
Keyword(s):  
Cell Cultures ◽  
Immobilized Cells ◽  
Neuroblastoma Cell ◽  
Three Dimensional ◽  
3D Cell Culture ◽  
Impedance Analysis ◽  
Neural Cells ◽  
Opposite Behavior ◽  
2D And 3D

In this work, the assessment of the interactions of a bioactive substance applied to immobilized cells in either a two-dimensional (2D) or three-dimensional (3D) arrangement mimicking in vivo tissue conditions is presented. In particular, dopamine (DA) was selected as a stimulant for the implementation of an impedance analysis with a specific type of neural cells (murine neuroblastoma). The aim of this study was the extraction of calibration curves at various frequencies with different known dopamine concentrations for the description of the behavior of dopamine applied to 2D and 3D cell cultures. The results present the evaluation of the mean impedance value for each immobilization technique in each frequency. The differential responses showed the importance of the impedance when frequency is applied in both 2D and 3D immobilization cases. More specifically, in 2D immobilization matrix impedance shows higher values in comparison with the 3D cell culture. Additionally, in the 3D case, the impedance decreases with increasing concentration, while in the 2D case, an opposite behavior was observed.

scholarly journals Come Back Skinfolds, All Is Forgiven: A Narrative Review of the Efficacy of Common Body Composition Methods in Applied Sports Practice

Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1075
Author(s):  
Andreas M. Kasper ◽  
Carl Langan-Evans ◽  
James F. Hudson ◽  
Thomas E. Brownlee ◽  
Liam D. Harper ◽  
...  
Keyword(s):  
Body Composition ◽  
Three Dimensional ◽  
Bioelectrical Impedance ◽  
Impedance Analysis ◽  
Skinfold Thickness ◽  
Fat Free Mass ◽  
Assessment Tools ◽  
Ultra Sound ◽  
Hydration Status ◽  
Routine Practice

Whilst the assessment of body composition is routine practice in sport, there remains considerable debate on the best tools available, with the chosen technique often based upon convenience rather than understanding the method and its limitations. The aim of this manuscript was threefold: (1) provide an overview of the common methodologies used within sport to measure body composition, specifically hydro-densitometry, air displacement plethysmography, bioelectrical impedance analysis and spectroscopy, ultra-sound, three-dimensional scanning, dual-energy x-ray absorptiometry (DXA) and skinfold thickness; (2) compare the efficacy of what are widely believed to be the most accurate (DXA) and practical (skinfold thickness) assessment tools and (3) provide a framework to help select the most appropriate assessment in applied sports practice including insights from the authors’ experiences working in elite sport. Traditionally, skinfold thickness has been the most popular method of body composition but the use of DXA has increased in recent years, with a wide held belief that it is the criterion standard. When bone mineral content needs to be assessed, and/or when it is necessary to take limb-specific estimations of fat and fat-free mass, then DXA appears to be the preferred method, although it is crucial to be aware of the logistical constraints required to produce reliable data, including controlling food intake, prior exercise and hydration status. However, given the need for simplicity and after considering the evidence across all assessment methods, skinfolds appear to be the least affected by day-to-day variability, leading to the conclusion ‘come back skinfolds, all is forgiven’.

Simulations of Realizable Photonic Bandgap Structures with High Refractive Contrast

2001 ◽  
Vol 694 ◽  
Author(s):  
Bonnie Gersten ◽  
Jennifer Synowczynski
Keyword(s):  
Periodic Structures ◽  
Photonic Band Gap ◽  
Three Dimensional ◽  
Face Centered Cubic ◽  
High Permittivity ◽  
Face Centered ◽  
Photonic Bandgap Structures ◽  
Photonic Band ◽  
Opal Crystal ◽  
Periodic Arrangement

AbstractThe transfer matrix method (TMM) software (Translight, A. Reynolds [1]) was used to evaluate the photonic band gap (PBG) properties of the periodic arrangement of high permittivity ferroelectric composite (40 wt% Ba0.45Sr0.55TiO3 /60 wt% MgO composite, εR= 80, tanδ = 0.0041 at 10 GHz) in air (or Styrofoam, εR~ 1) matrix compared to a lower permittivity material (Al2O3, εR= 11.54, tanδ = 0.00003 at 10 GHz) in air. The periodic structures investigated included a one-dimensional (1D) stack and a three-dimensional (3D) face centered cubic (FCC) opal structure. The transmission spectrum was calculated for the normalized frequency for all incident angles for each structure. The results show that the bandgaps frequency increased and the bandgap width increased with increased permittivity. The effects of orientation of defects in the opal crystal were investigated. It was found by introducing defects propagation bands were introduced. It was concluded that a full PBG is possible with the high permittivity material.

scholarly journals Stereo Perfect Metamaterial Absorber Based on Standing Gear-Shaped Resonant Structure With Wide-Incident-Angle Stability

2020 ◽  
Vol 8 ◽  
Author(s):  
Guangsheng Deng ◽  
Kun Lv ◽  
Hanxiao Sun ◽  
Zhiping Yin ◽  
Jun Yang
Keyword(s):  
Incident Angle ◽  
Structural Parameters ◽  
Three Dimensional ◽  
Dielectric Substrate ◽  
Metamaterial Absorber ◽  
Center Frequency ◽  
Resonant Structure ◽  
Potential Applications ◽  
Angle Stability ◽  
Perfect Metamaterial Absorber

In this work, a single-band metamaterial absorber (MA) based on a three dimensional (3D) resonant structure is presented. The unit cell is composed of a standing gear-shaped resonator, which is embedded in the dielectric substrate. The proposed 3D MA is ultrathin with a total thickness of 2.3 mm, corresponding 0.077λ0 at its center frequency. The simulation results demonstrate a high absorption peak at 10.1 GHz with absorptivity of 99.9%. The proposed 3D MA is insensitive to the polarization of the incident wave due to its rotationally symmetric structure. Moreover, the proposed 3D MA exhibits a wide-incident-angle stability, as absorptivity of more than 85% can be achieved for both TE and TM incidences with incident angle up to 60°. Most importantly, multiband electromagnetic wave absorption of the stereo MA can be enabled by adjusting the structural parameters of the standing gear. The proposed structure is compatible with 3D printing technology and has potential applications in electromagnetic shielding.

Simulations of Realizable Photonic Bandgap Structures with High Refractive Contrast

2001 ◽  
Vol 692 ◽  
Author(s):  
Bonnie Gersten ◽  
Jennifer Synowczynski
Keyword(s):  
Periodic Structures ◽  
Photonic Band Gap ◽  
Three Dimensional ◽  
Face Centered Cubic ◽  
High Permittivity ◽  
Face Centered ◽  
Photonic Bandgap Structures ◽  
Photonic Band ◽  
Opal Crystal ◽  
Periodic Arrangement

AbstractThe transfer matrix method (TMM) software (Translight, A. Reynolds [1]) was used to evaluate the photonic band gap (PBG) properties of the periodic arrangement of high permittivity ferroelectric composite (40 wt% Ba0.45Sr0.55TiO3/60 wt% MgO composite, εR = 80, tanδ?= 0.0041 at 10 GHz) in air (or Styrofoam, εR ∼ 1) matrix compared to a lower permittivity material (Al2O3, εR = 11.54, tanδ?= 0.00003 at 10 GHz) in air. The periodic structures investigated included a one-dimensional (1D) stack and a three-dimensional (3D) face centered cubic (FCC) opal structure. The transmission spectrum was calculated for the normalized frequency for all incident angles for each structure. The results show that the bandgaps frequency increased and the bandgap width increased with increased permittivity. The effects of orientation of defects in the opal crystal were investigated. It was found by introducing defects propagation bands were introduced. It was concluded that a full PBG is possible with the high permittivity material.

Substrate-Mediated Broadband Tunability in Plasmonic Resonances of Metal Nanoantennas on Finite High-Permittivity Dielectric Substrate

Plasmonics ◽  
2015 ◽  
Vol 10 (6) ◽  
pp. 1663-1673 ◽  
Author(s):  
Debabrata Sikdar ◽  
Weiren Zhu ◽  
Wenlong Cheng ◽  
Malin Premaratne
Keyword(s):  
Dielectric Substrate ◽  
High Permittivity

scholarly journals Flexible three-dimensional printed antenna substrates

2015 ◽  
Vol 2015 (8) ◽  
pp. 258-260 ◽  
Author(s):  
Syed Sheheryar Bukhari ◽  
William G. Whittow ◽  
Johan Joubert ◽  
John (Yiannis) Costas Vardaxoglou
Keyword(s):  
Three Dimensional ◽  
Printed Antenna

Fabrication and Composition Control of Three-Dimensional Dielectric Metal Microstructure Using Photocatalyst Nanoparticles

2014 ◽  
Vol 8 (4) ◽  
pp. 523-529 ◽  
Author(s):  
Hisamichi Yoshigoe ◽  
◽  
Shotaro Kadoya ◽  
Satoru Takahashi ◽  
Kiyoshi Takamasu
Keyword(s):  
Three Dimensional ◽  
Silver Ions ◽  
Dielectric Materials ◽  
Fabrication Method ◽  
High Permittivity ◽  
Composition Control ◽  
Electromagnetic Devices ◽  
Electromagnetic Characteristics ◽  
Metal Microstructure ◽  
Micro Structures

Recently, three-dimensional microstructures have been attracting much attention because of their potential application to electromagnetic devices operating with specific frequencies such as THz wave. For suitability in such applications, the structures often need to have complex three-dimensional shapes, be smaller than or at least as small as the applied wavelengths, consist of metals or dielectric materials, and have certain electromagnetic characteristics such as high permittivity. Although there are several methods for fabricating micro-structures, few of them satisfy all of these conditions. We propose a new fabrication method for dielectric-metal three-dimensional structures with sizes of a few tens of micrometers. The main feature of our method is the extraction of metal using photocatalyst nanoparticles. Silver ions in solution are reduced to neutral silver by electrons from the photocatalyst nanoparticles. Experimental results show that our system can be used to fabricate threedimensional structures, and we propose a new method for controlling the composition of the structures.

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