Theory of inductive shielding

1968 ◽  
Vol 46 (16) ◽  
pp. 1745-1752 ◽  
Author(s):  
R. W. Latham ◽  
K. S. H. Lee
Keyword(s):  
Boundary Conditions ◽  
Mathematical Theory ◽  
Arbitrary Shape ◽  
Low Frequency ◽  
Electromagnetic Shielding ◽  
Thin Shells ◽  
Shielding Effectiveness ◽  
Mathematical Methods ◽  
Electrical Thickness

A mathematical theory of low-frequency electromagnetic shielding is constructed on the basis that an appropriate set of boundary conditions can be derived to duplicate the effect of the shield's wall on the fields within the shield. Shields with electrically thin shells are considered in detail; mathematical methods that are best suited for computational purposes are presented for calculating the shielding effectiveness of such a shield of arbitrary shape. Shells with arbitrary electrical thickness are also treated, but in less detail, since the shielding problem involving this kind of shell is shown to be different from but no more general than the shielding problem involving electrically thin shells. Explicit results are given for shields of particular shape.

Effectiveness of Low Frequency Electromagnetic Shielding of Concrete with the Functionally Primitives Materials of Short Carbon Fibers and Graphite

2011 ◽  
Vol 189-193 ◽  
pp. 4297-4303 ◽  
Author(s):  
Fa Qin Dong ◽  
Qiong Si
Keyword(s):  
Carbon Fibers ◽  
Low Frequency ◽  
Electromagnetic Shielding ◽  
Shielding Effectiveness ◽  
Frequency Range ◽  
Shielding Properties ◽  
Electromagnetic Shielding Effectiveness ◽  
Short Carbon

The electromagnetic shielding properties of short carbon fibers and graphite concrete were investigated, and the influence of the contents of the short carbon fibers and graphite on the electromagnetic shielding effectiveness of the concrete in low frequency was studied. The mechanism causing the influence of the short carbon fibers adulteration on the electromagnetic shielding effectiveness of the graphite concrete at low frequency was investigated. The maximum electromagnetic shielding effectiveness was up to 8.5dB in the low frequency range of 1MHz～1.8GH. The results of the investigation provide the basis for further designing and producing of high-powered electromagnetic shielding concrete at low frequency.

scholarly journals Evaluating of Electromagnetic Shielding Characteristics of Reinforced Concrete Using Reinforcing Details

2020 ◽  
Vol 20 (5) ◽  
pp. 245-254
Author(s):  
JinSeok Choi ◽  
TianFeng Yuan ◽  
SeHee Hong ◽  
YoungSoo Yoon
Keyword(s):  
Reinforced Concrete ◽  
Frequency Band ◽  
Steel Fiber ◽  
Low Frequency ◽  
Volume Ratio ◽  
Experimental Tests ◽  
Electromagnetic Shielding ◽  
Fiber Reinforced Concrete ◽  
Shielding Effectiveness ◽  
Fiber Volume

In this study, experimental tests were performed to determine the electromagnetic shielding characteristics of reinforced concrete based on the thickness of concrete and rebar. In addition, the electromagnetic shielding characteristics based on the steel-fiber volume ratio and rebar spacing of fiber-reinforced concrete were evaluated. Concrete showed significant Shielding Effectiveness (SE) in a high-frequency band with increasing thickness, but the rebar exhibited significant SE in the low-frequency band with increasing diameter, decreasing rebar spacing, and increasing layer. The SE increased with the steel fiber volume ratio, and it also increased owing to the decrease in the rebar spacing for 1.5 vol.% steel fibers.

Realization of electromagnetic shielding performance for polyimide-matrix composite by self-metallization

2021 ◽  
pp. 002199832110316
Author(s):  
Jiayang Zhang ◽  
Hongjiang Ni ◽  
Ming Gong ◽  
Jun Li ◽  
Daijun Zhang ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Matrix Composite ◽  
Electromagnetic Interference ◽  
Interfacial Strength ◽  
Amic Acid ◽  
Thermal Reduction ◽  
Electromagnetic Shielding ◽  
Shielding Effectiveness ◽  
Heat Condition ◽  
Electromagnetic Interference Shielding Effectiveness

Electromagnetic shielding performance has been achieved for a polyimide (PI)-matrix composite by the strategy of self-metallization of its thermosetting PI matrix. Self-metallization of the thermosetting PI was realized by silver ion/poly(amic acid) (PAA) precursor ion exchange and thermal reduction. The factors influencing the self-metallization were investigated. The electrical conductivity and integrity for the surface of the PI were achieved by optimization of ion exchange/thermal reduction parameters. The fabricated PI-matrix composite exhibits a maximum electromagnetic interference shielding effectiveness value of 81 dB. Importantly, the electromagnetic shielding performance can be maintained even after heat condition of 300°C. Meanwhile, the surface-metallized PI composite exhibits mechanical property equivalent to the pristine composite, and an Ag/matrix interfacial strength higher than 19.6 MPa. Besides, self-metallization mechanism of the thermosetting PI was investigated.

Analyses on the Manufacture and Physical Properties of Electromagnetic Shielding/ Far Infrared Ray Nonwoven

2010 ◽  
Vol 97-101 ◽  
pp. 1790-1793
Author(s):  
Jia Horng Lin ◽  
Yu Tien Huang ◽  
Chin Mei Lin ◽  
Yi Chang Yang ◽  
Chien Teng Hsieh ◽  
...  
Keyword(s):  
Physical Properties ◽  
Far Infrared ◽  
Electromagnetic Shielding ◽  
Breaking Force ◽  
Shielding Effectiveness ◽  
Machine Direction ◽  
Tear Strength ◽  
Burst Strength ◽  
Far Infrared Ray ◽  
Electromagnetic Shielding Effectiveness

According to the results, when low melting polyester fiber increased to be 20%, the electromagnetic shielding/ far infrared ray nonwoven obtained the optimum burst strength, maximum breaking force and maximum tear strength, and they were as follows: burst strength was 4.2 kgf/cm2; maximum breaking force was 153.59 N in the cross machine direction and 70.80 N in the machine direction; maximum tear strength was 215.77 N in cross machine direction and 117.07 N in machine direction; and optimum electromagnetic shielding effectiveness (EMSE) was 45 dB.

A Systematic Asymptotic Expansion Procedure for Slender Ships

1964 ◽  
Vol 8 (03) ◽  
pp. 15-23 ◽  
Author(s):  
E. O. Tuck
Keyword(s):  
Asymptotic Expansion ◽  
Boundary Conditions ◽  
Arbitrary Shape ◽  
Careful Consideration ◽  
Wave Resistance ◽  
Expansion Procedure ◽  
Systematic Solution ◽  
The Individual ◽  
Correct Boundary Conditions

Inner and outer expansions are used to formulate a systematic solution to the problem of the steady translation of a slender ship of arbitrary shape. Careful consideration is givien to finding the correct boundary conditions to be satisfied by successive terms in the expansions, and certain of the individual terms are determined partly or completely as functions of hull shape. Some results are given concerning the second approximations to the potential and wave resistance.

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