Shielding of electromagnetic radiation by multilayer textile sets

2018 ◽  
Vol 89 (6) ◽  
pp. 948-958 ◽  
Author(s):  
Katarzyna Marciniak ◽  
Katarzyna Ewa Grabowska ◽  
Zbigniew Stempień ◽  
Izabela Luiza Ciesielska-Wróbel
Keyword(s):  
Stainless Steel ◽  
Electromagnetic Radiation ◽  
Copper Wire ◽  
Single Layer ◽  
Woven Fabric ◽  
Cotton Yarn ◽  
Hybrid Yarn ◽  
Number Of Layers ◽  
Fabric Construction ◽  
Copper Coil

This paper presents the continuation of research on shielding efficiency (SE) of electromagnetic radiation (EMR) by woven fabric made of cotton (warps and wefts) and a hybrid yarn (wefts). This hybrid yarn was made of stainless steel yarn by Bekinox wrapped with an enamelled copper wire from Synflex Elektro GmbH, Germany. The pitch of copper coil on a hybrid yarn equals 3 mm. The wefts were introduced into the fabric in the following order: 1 hybrid yarn, 1 cotton yarn, 1 hybrid yarn, 1 cotton yarn, etc. The construction of this specific fabric was proven to be the most efficient in terms of the hybrid weft construction and the fabric construction to shield EMR among other previously tested fabrics with different weft configuration. The current study proposes to verify the effect of the number of layers of the fabrics and their mutual configuration on the final SE of the multilayered set. Some of the most interesting findings of this study are that increasing the number of layers placed on top of one another with an offset angle of 0° to more than two does not provide a higher SE; however, using three such layers provides an SE of 56 dB, which is over two times higher than that provided by a single layer. Increasing the number of layers of fabric aligned at an angle of 45° provides a higher SE only for a frequency of 30 MHz.

scholarly journals The effects of metal type, number of layers, and hybrid yarn placement on the absorption and reflection properties in electromagnetic shielding of woven fabrics

2019 ◽  
Vol 14 ◽  
pp. 155892501986096 ◽  
Author(s):  
Ilkan Özkan ◽  
Abdurrahman Telli
Keyword(s):  
Stainless Steel ◽  
Woven Fabrics ◽  
Electromagnetic Shielding ◽  
Woven Fabric ◽  
Power Ratio ◽  
Shielding Effectiveness ◽  
Hybrid Yarn ◽  
Number Of Layers ◽  
Absorbed Power ◽  
Electromagnetic Shielding Effectiveness

In this study, stainless steel, copper, and silver wires were intermingled with two polyamide 6.6 filaments through the commingling technique to produce three-component hybrid yarns. The produced hybrid yarns were used as weft in the structure of plain woven fabric samples. The electromagnetic shielding effectiveness parameters of samples were measured in the frequency range of 0.8–5.2 GHz by the free space technique. The effects of metal hybrid yarn placement, number of fabric layers, metal types, and wave polarization on the electromagnetic shielding effectiveness and absorption and reflection properties of the woven fabrics were analyzed statistically at low and high frequencies separately. As a result, the samples have no shielding property in the warp direction. Metal types show no statistically significant effect on electromagnetic shielding effectiveness. However, fabrics containing stainless steel have a higher absorption power ratio than copper and silver samples. Double-layer samples have higher electromagnetic shielding effectiveness values than single-layer fabrics in both frequency ranges. However, the number of layers does not have a significant effect on the absorbed and reflected power in the range of 0.8–2.6 GHz. There was a significant difference above 2.6 GHz frequency for absorbed power ratio. An increase in the density of hybrid yarns in the fabric structure leads to an increase in the electromagnetic shielding effectiveness values. Two-metal placement has a higher absorbed power than the full and one-metal placements, respectively. The samples which have double layers and including metal wire were in their all wefts reached the maximum electromagnetic shielding effectiveness values for stainless steel (78.70 dB), copper (72.69 dB), and silver composite (57.50 dB) fabrics.

scholarly journals A Study on Sulphonated Jute-cotton Blended Yarn and Fabrics and their Characteristics

1970 ◽  
Vol 42 (3) ◽  
pp. 281-286
Author(s):  
MA Salam ◽  
FI Farouqui ◽  
Md IH Mondal
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Key Words ◽  
Woven Fabric ◽  
Cotton Yarn ◽  
Jute Fibre ◽  
Blended Yarn ◽  
Fabric Construction ◽  
The One ◽  
Jute Yarn

Sulphonated jute fibres were blended with cotton at three different ratios, e g. 50:50, 60:40 and 70:30 for production of fine yarn and comparatively better ratio have been investigated. The plain woven fabric were prepared by sulphonated jute-cotton yarn. The set of warp and weft blended yarns was done on the one up and one down principle. The physico-mechanical properties of blended yarn and fabrics were studied and compared with that of jute yarn, cotton yarn and fabric. Key words: Sulphonated jute fibre, jute-cotton blend, mechanical properties, tensile strength and fabric construction. Bangladesh J. Sci. Ind. Res. 42(3), 281-286, 2007

Determination of the pore size of woven structures through image analysis

2012 ◽  
Vol 2 (1) ◽  
Author(s):  
R. Angelova
Keyword(s):  
Pore Size ◽  
Single Layer ◽  
Woven Fabric ◽  
Virtual Model ◽  
Experimental Procedure ◽  
Porosity And Permeability ◽  
Woven Structures ◽  
Woven Structure ◽  
Non Destructive

AbstractThe paper presents an experimental procedure developed for determination of the pore size, shape and distribution in a single layer woven fabric, for the construction of a virtual model to be incorporated in a future CFD software package. The procedure is based on non-destructive observation and analysis of woven samples. 14 different samples of gray fabrics of 100 % cotton in plain and twill weaves are investigated. The results obtained allow the creation of reality more realistic virtual model of the woven structure, and theoretical investigation of its porosity and permeability through computer simulation.

Explosively Driven Expansion and Fragmentation Behavior for Cylinders, Spheres and Rings of 304 Stainless Steel

2010 ◽  
Vol 638-642 ◽  
pp. 1035-1040 ◽  
Author(s):  
Tetsuyuki Hiroe ◽  
Kazuhito Fujiwara ◽  
Hidehiro Hata ◽  
Mitsuru Yamauchi ◽  
Kiyotaka Tsutsumi ◽  
...  
Keyword(s):  
Stainless Steel ◽  
High Speed ◽  
Fracture Behavior ◽  
Copper Wire ◽  
304 Stainless Steel ◽  
Fragmentation Model ◽  
Fragmentation Behavior ◽  
Deformation And Fracture ◽  
Test Parameters ◽  
Fine Copper

Explosive loading techniques are applied to expand tubular cylinders, spherical shells and rings of 304 stainless steel to fragmentation, and the effects of wall thicknesses, explosive driver diameters and the constant proportionality of the in-plane biaxial stretching rates are investigated on the deformation and fracture behavior of three basic structures experimentally and numerically. In the cylinder tests, the driver is a column of high explosive PETN, inserted coaxially into the bore of a cylinder and initiated by exploding a fine wire bundle at the column axis using a discharge current from a high-voltage capacitor bank. In case of the ring tests, ring specimens are placed onto a single cylinder filled with the PETN as a expansion driver, and for sphere tests, specimens filled with the PETN are also initiated by exploding a fine copper wire line with small length located at the central point. Two types of experiments are conducted for every specimen and test condition. The first type uses high speed cameras to observe the deformation and crack generation of expanding specimens showing the final maximum in-plane stretching rate of above , and the second uses soft capturing system recovering typically most fragments successfully. The fragments are measured and investigated using a fragmentation model. The effects of test parameters on the deformation and fracture behavior for three types of structures are discussed in need of modified fragmentation model for shell structural elements.

Plasmon modes in N-layer silicene structures

2021 ◽  
Author(s):  
Men Nguyen Van
Keyword(s):  
Electric Field ◽  
Random Phase ◽  
Single Layer ◽  
Plasmon Mode ◽  
Orbit Coupling ◽  
Collective Excitations ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Number Of Layers ◽  
Plasmon Modes

Abstract We investigate the plasmon properties in N-layer silicene systems consisting of N, up to 6, parallel single-layer silicene under the application of an out-of-plane electric field, taking into account the spin-orbit coupling within the random-phase approximation. Numerical calculations demonstrate that N undamped plasmon modes, including one in-phase optical and (N-1) out-of-phase acoustic modes, continue mainly outside the single-particle excitation area of the system. As the number of layers increases, the frequencies of plasmonic collective excitations increase and can become much larger than that in single layer silicene, more significant for high-frequency modes. The optical (acoustic) plasmon mode(s) noticeably (slightly) decreases with the increase in the bandgap and weakly depends on the number of layers. We observe that the phase transition of the system weakly affects the plasmon properties, and as the bandgap caused by the spin-orbit coupling equal that caused by the external electric field, the plasmonic collective excitations and their broadening function in multilayer silicene behave similarly to those in multilayer gapless graphene structures. Our investigations show that plasmon curves in the system move toward that in single layer silicene as the separation increases, and the impacts of this factor can be raised by a large number of layers in the system. Finally, we find that the imbalanced carrier density between silicene layers significantly decreases plasmon frequencies, depending on the number of layers.

Stacked Microchannel Heat Sinks for Liquid Cooling of Microelectronic Components

2000 ◽  
Author(s):  
X. Wei ◽  
Y. Joshi
Keyword(s):  
Flow Rate ◽  
Heat Sink ◽  
Water Flow Rate ◽  
Heat Removal ◽  
Single Layer ◽  
Heat Sinks ◽  
Computationally Efficient ◽  
Liquid Cooling ◽  
Number Of Layers ◽  
Microelectronic Components

Abstract A novel heat sink based on a multi-layer stack of liquid cooled microchannels is investigated. For a given pumping power and heat removal capability for the heat sink, the flow rate across a stack of microchannels is lower compared to a single layer of microchannels. Numerical simulations using a computationally efficient multigrid method [1] were carried out to investigate the detailed conjugate transport within the heat sink. The effects of the microchannel aspect ratio and total number of layers on thermal performance were studied for water as coolant. A heat sink of base area 10 mm by 10 mm with a height in the range 1.8 to 4.5 mm (2–5 layers) was considered with water flow rate in the range 0.83×10−6 m3/s (50 ml/min) to 6.67×10−6 m3/s (400 ml/min). The results of the computational simulations were also compared with a simplified thermal resistance network analysis.

An overview of deep learning techniques

2018 ◽  
Vol 66 (9) ◽  
pp. 690-703 ◽  
Author(s):  
Michael Vogt
Keyword(s):  
Deep Learning ◽  
Single Layer ◽  
Visual Image ◽  
Image Understanding ◽  
Number Of Layers ◽  
Box Models ◽  
Learning Techniques ◽  
Engineering Work ◽  
Computational Resources ◽  
Black Box Models

Abstract Deep learning is the paradigm that profoundly changed the artificial intelligence landscape within only a few years. Although accompanied by a variety of algorithmic achievements, this technology is disruptive mainly from the application perspective: It considerably pushes the border of tasks that can be automated, changes the way products are developed, and is available to virtually everyone. Subject of deep learning are artificial neural networks with a large number of layers. Compared to earlier approaches with ideally a single layer, this allows using massive computational resources to train black-box models directly on raw data with a minimum of engineering work. Most successful applications are found in visual image understanding, but also in audio and text modeling.

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