Radar Absorbing Materials Based on Metamaterials

2010 ◽  
Vol 75 ◽  
pp. 215-223
Author(s):  
Andrey Nikolayevich Lagarkov ◽  
Vladimir Nikolayevich Kisel ◽  
Vladimir Nikolayevich Semenenko
Keyword(s):  
Electromagnetic Wave ◽  
Reflection Coefficient ◽  
Frequency Band ◽  
Radar Absorbing Material ◽  
Wide Range ◽  
Absorbing Materials ◽  
Different Types ◽  
Absorbing Material ◽  
Wave Incidence

The use of metamaterial for design of radar absorbing material (RAM) is discussed. The typical features of the frequency dependencies of , , ,  of composites manufactured of different types of resonant inclusions are given as an example. The RAM characteristics obtained by the use of the composites are given. It is shown that it is possible to use for RAM design the metamaterials with both the positive values of ,  and negative ones. Making use of the frequency band with negative  and  it is possible to create a RAM with low reflection coefficient in a wide range of the angles of electromagnetic wave incidence.

scholarly journals Oblique Wide-Angle Multi-Sector Metamaterial Absorber for Space Applications

2019 ◽  
Vol 9 (16) ◽  
pp. 3425 ◽  
Author(s):  
Olivier Rance ◽  
Anne Claire Lepage ◽  
Xavier Begaud ◽  
Kevin Elis ◽  
Nicolas Capet
Keyword(s):  
Reflection Coefficient ◽  
Frequency Band ◽  
Oblique Incidence ◽  
Metamaterial Absorber ◽  
Wide Angle ◽  
Space Applications ◽  
Specific Measurement ◽  
Measurement Results ◽  
Absorbing Material

This article presents the design, realization and measurement of lightweight absorbing material for space applications. The electromagnetic absorber, operating on the [2 GHz, 2.3 GHz] frequency band, is designed for oblique incidence ranging from 35° to 65°. Wide-angle designs are demonstrated to be particularly challenging at oblique incidence and an approach consisting in dividing the surface in two different sectors with respect to the incoming angle is proposed. A specific measurement setup is presented in order to characterize this new kind of evolutive absorber. The measurement results show that the sectorial absorber achieves a reflection coefficient inferior to −11.5 dB, corresponding to an absorptivity above 0.965 on the frequency band [2 GHz, 2.3 GHz] for both TE and TM polarizations for angles of incidence varying from 35° to 65°.

scholarly journals Improvement of the sound absorption performance of jute felt-based sound absorbers using micro-perforated panels

2017 ◽  
Vol 36 (4) ◽  
pp. 376-398 ◽  
Author(s):  
Pritesh V Bansod ◽  
T Sai Teja ◽  
Amiya R Mohanty
Keyword(s):  
Transfer Matrix Method ◽  
Sound Absorption ◽  
Low Cost ◽  
Control Engineering ◽  
Natural Materials ◽  
Sound Absorber ◽  
Absorbing Materials ◽  
Different Types ◽  
Absorbing Material ◽  
Absorption Performance

In industrial and architectural applications, noise can be controlled using sound-absorbing materials. Natural materials are now gaining importance in the noise control engineering as they have advantages like low cost, eco-friendly, easy to produce, etc. Jute is one of such natural materials, which can be used as a sound-absorbing material. Micro-perforated panels along with three different types of jute felts are used in a multilayer sound absorber configuration to improve its sound absorption. The sound absorption performance of these multilayer sound absorbers is evaluated by using the transfer matrix method and experimental method. Dependence of sound absorption performance on the placement of micro-perforated panels in a multilayer sound absorber is also studied. It is observed that the sound absorption performance depends on the position of micro-perforated panels in a multilayer sound absorber.

Investigating the electromagnetic wave-absorbing capacity and mechanical properties of flexible radar-absorbing knitted compound materials

2019 ◽  
pp. 152808371987700
Author(s):  
Niuniu Chen ◽  
Sainan Wei ◽  
Bao Shi ◽  
Ruosi Yan ◽  
Xianghong Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electromagnetic Wave ◽  
Convex Surface ◽  
Military Technology ◽  
Radar Absorbing Material ◽  
Compound Material ◽  
Textile Technology ◽  
Aerospace Technology ◽  
Absorbing Material ◽  
Compound Materials

This study fabricated flexible radar-absorbing knitted compound materials by weft knitting and blending ferromagnetic nickel micron-fibers and cotton fiber into structures with a concave–convex surface, including rhombic, mat, wavy, and leno stitches. The electromagnetic wave-absorbing capability and mechanical properties of the flexible radar-absorbing knitted compound materials were evaluated. The results showed that the rhombic, mat, and wavy stitches displayed high mechanical properties with high bursting strength and there were no significant differences among them. The rhombic stitch flexible radar-absorbing knitted compound material with a ferromagnetic nickel micron-fiber content of 14% had a maximum bandwidth of 13 GHz and achieved a minimum reflectance of −20 dB at 7 GHz, which was 150% that of mat fabric, and 200% that of wavy fabric and leno fabric. This was ascribed to the fact that the concave–convex surface with regular diamond-shaped block improved the dispersion of the electromagnetic wave, weakened the wave strength, and increased the interference. Therefore, the rhombic stitch flexible radar-absorbing knitted compound material was the most suitable for flexible radar-absorbing material in this study. The development of flexible radar-absorbing materials, by combining aerospace technology, military technology and textile technology, is important for the application in stealth of aircraft and weapons.

scholarly journals Preparation and properties of CF–Fe3O4–BN composite electromagnetic wave-absorbing materials

RSC Advances ◽  
2020 ◽  
Vol 10 (19) ◽  
pp. 11121-11131 ◽  
Author(s):  
Wei Ye ◽  
Qilong Sun ◽  
Xiaoyun Long ◽  
Yingying Cai
Keyword(s):  
Electromagnetic Wave ◽  
Carbon Fiber ◽  
Boron Nitride ◽  
Absorbing Materials ◽  
Absorbing Material

A three-layered electromagnetic (EM) wave-absorbing material was prepared by depositing a Fe3O4 and boron nitride (BN) coating onto the surface of a carbon fiber (CF) by in situ hybridization.

Properties of Propagation of Electromagnetic Wave in a Multilayer Radar-Absorbing Structure With Plasma- and Radar-Absorbing Material

2011 ◽  
Vol 39 (9) ◽  
pp. 1768-1775 ◽  
Author(s):  
Cheng-Xun Yuan ◽  
Zhong-Xiang Zhou ◽  
Jingwen W. Zhang ◽  
Xiao-Li Xiang ◽  
Yue Feng ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Radar Absorbing Material ◽  
Absorbing Material ◽  
Radar Absorbing Structure

scholarly journals Analysis of the Types of Radar Absorbing Materials

2019 ◽  
pp. 35-38
Author(s):  
Anatoly Afanasiev ◽  
Yulia Bakhracheva
Keyword(s):  
Radar Absorbing Material ◽  
Absorbing Materials ◽  
Absorbing Material

The paper provides the analysis of modern radar absorbing materials. The authors describe the advantage of radar absorbing material on the basis of the metamaterial.

Nanoparticles Functionalized with Venom-Derived Peptides and Toxins for Pharmaceutical Applications

2020 ◽  
Vol 21 (2) ◽  
pp. 97-109 ◽  
Author(s):  
Ana P. dos Santos ◽  
Tamara G. de Araújo ◽  
Gandhi Rádis-Baptista
Keyword(s):  
Oral Absorption ◽  
Current Data ◽  
Pharmacological Activities ◽  
Venom Peptides ◽  
Essential Components ◽  
Wide Range ◽  
Different Types ◽  
Direct Use ◽  
Animal Venoms ◽  
Pharmaceutical Biotechnology

Venom-derived peptides display diverse biological and pharmacological activities, making them useful in drug discovery platforms and for a wide range of applications in medicine and pharmaceutical biotechnology. Due to their target specificities, venom peptides have the potential to be developed into biopharmaceuticals to treat various health conditions such as diabetes mellitus, hypertension, and chronic pain. Despite the high potential for drug development, several limitations preclude the direct use of peptides as therapeutics and hamper the process of converting venom peptides into pharmaceuticals. These limitations include, for instance, chemical instability, poor oral absorption, short halflife, and off-target cytotoxicity. One strategy to overcome these disadvantages relies on the formulation of bioactive peptides with nanocarriers. A range of biocompatible materials are now available that can serve as nanocarriers and can improve the bioavailability of therapeutic and venom-derived peptides for clinical and diagnostic application. Examples of isolated venom peptides and crude animal venoms that have been encapsulated and formulated with different types of nanomaterials with promising results are increasingly reported. Based on the current data, a wealth of information can be collected regarding the utilization of nanocarriers to encapsulate venom peptides and render them bioavailable for pharmaceutical use. Overall, nanomaterials arise as essential components in the preparation of biopharmaceuticals that are based on biological and pharmacological active venom-derived peptides.

Wetting of glass surface using natural surfactants

2020 ◽  
Vol 12 ◽  
Author(s):  
Nihar Ranjan Biswal
Keyword(s):  
Contact Angle ◽  
Glass Surface ◽  
Pure Water ◽  
Amyl Alcohol ◽  
Synthetic Surfactant ◽  
Wide Range ◽  
Different Types ◽  
Natural Surfactants ◽  
Triton X ◽  
Solid Liquid

Background: Surfactant adsorption at the interfaces (solid–liquid, liquid–air, or liquid–liquid) is receiving considerable attention from a long time due to its wide range of practical applications. Objective: Specifically wettability of solid surface by liquids is mainly measured by contact angle and has many practical importances where solid–liquid systems are used. Adsorption of surfactants plays an important role in the wetting process. The wetting behaviours of three plant-based natural surfactants (Reetha, Shikakai, and Acacia) on the glass surface are compared with one widely used nonionic synthetic surfactant (Triton X-100) and reported in this study. Methods: The dynamic contact angle study of three different types of plant surfactants (Reetha, Shikakai and Acacia) and one synthetic surfactant (Triton X 100) on the glass surface has been carried out. The effect of two different types of alcohols such as Methanol and amyl alcohol on wettability of shikakai, as it shows little higher value of contact angle on glass surface has been measured. Results: The contact angle measurements show that there is an increase in contact angle from 47° (pure water) to 67.72°, 65.57°, 68.84°, and 68.79° for Reetha, Acacia, Shikakai, and Triton X-100 respectively with the increase in surfactant concentration and remain constant at CMC. The change in contact angle of Shikakai-Amyl alcohol mixtures are slightly different than that of methanol-Shikakai mixture, mostly there is a gradual increase in contact angle with the increasing in alcohol concentration. Conclusion: There is no linear relationship between cos θ and inverse of surface tension. There was a linear increase in surface free energy results with increase in concentration as more surfactant molecules were adsorbing at the interface enhancing an increase in contact angle.

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