Experimental studies of magnetically scannable leaky-wave antennas having a corrugated ferrite slab/dielectric layer structure

1988 ◽  
Vol 36 (7) ◽  
pp. 911-917 ◽  
Author(s):  
H. Maheri ◽  
M. Tsutsumi ◽  
N. Kumagai
Keyword(s):  
Dielectric Layer ◽  
Layer Structure ◽  
Experimental Studies ◽  
Leaky Wave ◽  
Ferrite Slab

Tailoring the Dielectric Layer Structure for Enhanced Carrier Mobility in Organic Transistors: The Use of Hybrid Inorganic/Organic Multilayer Dielectrics

2016 ◽  
Vol 2 (5) ◽  
pp. 1500402 ◽  
Author(s):  
Muriel de Pauli ◽  
Ute Zschieschang ◽  
Ingrid D. Barcelos ◽  
Hagen Klauk ◽  
Angelo Malachias
Keyword(s):  
Dielectric Layer ◽  
Carrier Mobility ◽  
Layer Structure ◽  
Organic Transistors

Experimental studies of the effect of concentrated dynamic loads on a three-layer structure with a filler

2021 ◽  
pp. 20-21
Author(s):  
Keyword(s):  
Comparative Analysis ◽  
Glass Fiber ◽  
Impact Loading ◽  
Layer Structure ◽  
Experimental Studies ◽  
Theoretical Data ◽  
Dynamic Loads ◽  
Bearing Layer

The results of experimental studies of the effect of concentrated dynamic loads on a three-layer structure with glass fiber filler are presented. A comparative analysis of the obtained results with theoretical data is carried out. Keywords: three-layer structure, striker, bearing layer, fiberglass, impact loading. [email protected]

scholarly journals Theoretical and Experimental Analysis of Inter-Layer Stresses in Filament-Wound Cylindrical Composite Structures

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7037
Author(s):  
Piotr Krysiak ◽  
Aleksander Błachut ◽  
Jerzy Kaleta
Keyword(s):  
Composite Structures ◽  
Layer Structure ◽  
Experimental Studies ◽  
Internal Surface ◽  
Cylindrical Sample ◽  
Calculation Model ◽  
Internal Diameter ◽  
Steel Core ◽  
Filament Wound ◽  
Filament Wound Composite

This paper analyses the issues relative to the modelling of tubular (cylindrical) composite structures. This paper aims to describe the design of a multi-layer structure of filament-wound composite pipes where, after loading, the hoop-stress distribution would be as uniform as possible. That would allow the mass of the composite to decrease while maintaining the proper mechanical strength. This publication presents the development of a calculation model dedicated to mono- and multi-layered tubular composite structures. The equations describing the stress pattern were based on the Lamé Problem, whereas to describe the modelled structures, an anisotropy coefficient was introduced and interlayer pressures values were determined. To verify the calculations, experimental studies were performed. The test specimens were fabricated by winding fibre bundles around a steel core (as rings with an internal diameter of 113 mm and a height of 30 mm). For the test, the method of pressing a conical ring into a split ring, which acts on the internal surface of the tested cylindrical sample, was selected. The operation of the test rig (test stand) was simulated using the Finite Element Method (FEM). Measurements with strain gauges were conducted during the experiments.

scholarly journals Modernization of the construction of the crane traveling wheel

2021 ◽  
pp. 107
Author(s):  
Nаtalya Fidrovska ◽  
Evgen Slepuzhnikov ◽  
Alexsandr Chernyshenko ◽  
Igor Perevoznyk
Keyword(s):  
Stress State ◽  
Layer Structure ◽  
Experimental Studies ◽  
Vertical Direction ◽  
Lightweight Aggregate ◽  
Middle Layer ◽  
Vibration Acceleration ◽  
Idle Speed ◽  
Drive Wheel ◽  
Steel Material

The article discusses the modernization of the running wheel due to the introduction of an elastic element. The structure, which consists of three layers, the outer ones of which consist of strong steel material, and the middle layer consists of low-strength lightweight aggregate, which can significantly reduce dynamic forces, vibrations and shocks, which increases the reliability of cargo transportation. Calculations have shown that the stress state of a wheel with an elastic insert is less than that of an old-design travel wheel. The decrease in force and elastic factors in the travel wheel, which has an elastic insert, is explained by the fact that the use of an elastic ring leads to an increase in the bending stiffness of the outer ring of the shell. The obtained solution to the problem of the strength of a three-layer structure makes it possible to determine the stresses in the shell depending not only on its geometric parameters, but also on the shear modulus of the filler, which improves the reliability of the design and operation of such structures. Theoretical studies of the stress state of a three-layer cylindrical structure, taking into account the shear energy of the filler, makes it possible to assess the strength of such a structure and give certain recommendations for its use. Experimental studies that were carried out on an operating overhead crane fully confirmed a very significant reduction in oscillatory processes in travel wheels. The level of vibration acceleration in the vertical direction on the modernized drive wheel is almost 3 times less than the level of vibration acceleration on the drive wheel at idle speed of a conventional design.

Mechanisms of Layer Structure Formation in Peritectic Alloys

1997 ◽  
Vol 481 ◽  
Author(s):  
P. Mazumder ◽  
R. Trivedi ◽  
A. Karma
Keyword(s):  
Structure Formation ◽  
Layer Structure ◽  
Experimental Studies ◽  
Growth Conditions ◽  
Phase Region ◽  
Primary Phase ◽  
Two Phase ◽  
Novel Structure ◽  
Basic Ideas ◽  
Narrow Composition Range

ABSTRACTThe mechanisms of layer structure formation in the two phase region of peritectic systems are discussed. Under diffusive growth conditions, a banded structure is predicted within a narrow composition range in the hypoperitectic composition. Experimental studies show the formation of an oscillatory structure in the hyperperitectic region. It is shown that this structure is induced by convection in the melt, and it is a novel structure in which a large single tree-like structure of primary phase is surrounded by the peritectic phase. Basic ideas of convection that lead to this tree-like morphology are described.

Alternating-current driven quantum-dot light-emitting diodes with high brightness

Nanoscale ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 5231-5239 ◽  
Author(s):  
Fengtian Xia ◽  
Xiao Wei Sun ◽  
Shuming Chen
Keyword(s):  
Quantum Dot ◽  
Dielectric Layer ◽  
Light Emitting Diodes ◽  
Layer Structure ◽  
Alternating Current ◽  
High Brightness ◽  
Light Emitting

Highly bright alternating-current (AC) driven quantum-dot light-emitting diodes (QLEDs) are demonstrated based on a single dielectric layer structure.

Experimental Studies and Physical Model of Efficient, Tunable Injection Using Tunnel-Transparent Dielectric Contacts on Polymer Light-Emitting Devices

2002 ◽  
Vol 734 ◽  
Author(s):  
Ludmila Bakueva ◽  
Sergei Musikhin ◽  
Edward H. Sargent ◽  
Alexander Shik
Keyword(s):  
Dielectric Layer ◽  
Negative Differential Resistance ◽  
Voltage Drop ◽  
Strong Dependence ◽  
Experimental Studies ◽  
Differential Resistance ◽  
Hot Electron ◽  
Injection Efficiency ◽  
Light Emitting ◽  
Light Emitting Devices

ABSTRACTMost conducting polymers used for light-emitting devices have a small electron affinity, creating a high barrier for electron injection resulting in low injection efficiency. To improve injection characteristics, we fabricated and investigated multi-layer contacts with a tunneltransparent dielectric layer of nanometer thickness. Polymer layers were prepared by spin coating, and dielectric and metallic contact layers subsequently grown by vacuum deposition. Samples with such multi-layer cathodes demonstrated a current-voltage characteristic with negative differential resistance. At larger applied voltage, electroluminescence was observed with an efficiency larger than for a simple cathode of the same metal. We have developed a model to describe double injection through multi-layer contacts which explains these salient observed features. The increase in injection efficiency is caused by the voltage drop at the dielectric layer, shifting the metal Fermi level relative to the polymer molecular orbitals responsible for carrier transport. The negative differential resistance is explained by the strong dependence of dielectric tunnel transparency on voltage, a dependence which is qualitatively different for electrons and holes. Further flexibility in the functional characteristics of the injecting contacts is achieved through the use of an additional thin metallic layer playing the role of a base electrode, similar to hot-electron transistors with metallic base.

scholarly journals Design and Analysis of a Five-Band Polarization-Insensitive Metamaterial Absorber

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Han Wu ◽  
Shijun Ji ◽  
Ji Zhao ◽  
Chengxin Jiang ◽  
Handa Dai
Keyword(s):  
Dielectric Layer ◽  
Layer Structure ◽  
Surface Current ◽  
Metamaterial Absorber ◽  
Microwave Range ◽  
Absorption Mechanism ◽  
Resonant Frequencies ◽  
Resonator Structure ◽  
Dipole Resonance ◽  
Polarization Insensitive

A five-band metamaterial absorber (MMA) is presented. The proposed absorber consists of a three-layer structure of the top metal resonator, intermediate dielectric layer, and bottom metal plane. The top structure takes the centroid as the center and spreads out in a three-pronged shape with an average of 360°, and the ends bifurcate again. The calculation was carried out by the professional software to iteratively optimize the absorption effect of MMA in the microwave range. The results show that the MA has five peaks at resonant frequencies of 5.984 GHz, 12.232 GHz, 18.128 GHz, 18.414 GHz, and 20.592 GHz, with peaks of 0.9925, 0.9968, 0.9783, 0.9754, and 0.9975. By analyzing the electromagnetic field and surface current distribution of the absorber, the absorption mechanism is further verified, and the corresponding influence on the absorption spectrum is studied according to different polarization angles and incident angles. The effects of different resonator structure size and dielectric layer thickness on absorption rate were also discussed, and the distribution of electromagnetic fields is analyzed to reveal the existence of electric dipole resonance and magnetic resonance. Through comparing experiments and simulations, it is found that the peaks of the 1st, 2nd, and 5th have smaller absorption errors and frequency deviation, while the peaks of the 3rd and 4th have large ones. The five-band absorber has potential application in multiband electromagnetic stealth, bionic sensor, thermal radiation measuring instrument, and so on.

scholarly journals Enhanced biologically inspired model for image recognition based on a novel patch selection method with moment

2019 ◽  
Vol 17 (02) ◽  
pp. 1940007
Author(s):  
Yanfeng Lu ◽  
Lihao Jia ◽  
Hong Qiao ◽  
Yi Li ◽  
Zongshuai Qi
Keyword(s):  
Image Recognition ◽  
Gabor Filter ◽  
Layer Structure ◽  
Experimental Studies ◽  
Selection Method ◽  
Feature Representation ◽  
Patch Selection ◽  
Biologically Inspired ◽  
Multi Scale ◽  
Random Method

Biologically inspired model (BIM) for image recognition is a robust computational architecture, which has attracted widespread attention. BIM can be described as a four-layer structure based on the mechanisms of the visual cortex. Although the performance of BIM for image recognition is robust, it takes the randomly selected ways for the patch selection, which is sightless, and results in heavy computing burden. To address this issue, we propose a novel patch selection method with oriented Gaussian–Hermite moment (PSGHM), and we enhanced the BIM based on the proposed PSGHM, named as PBIM. In contrast to the conventional BIM which adopts the random method to select patches within the feature representation layers processed by multi-scale Gabor filter banks, the proposed PBIM takes the PSGHM way to extract a small number of representation features while offering promising distinctiveness. To show the effectiveness of the proposed PBIM, experimental studies on object categorization are conducted on the CalTech05, TU Darmstadt (TUD) and GRAZ01 databases. Experimental results demonstrate that the performance of PBIM is a significant improvement on that of the conventional BIM.

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