scholarly journals COMPOSED TECHNIQUES FOR OBTAINING OF THE 3D HYBRID COMPOSITES FOR ATTENUATION OF ELECTROMAGNETIC FIELD

2019 ◽  
Vol 2019 ◽  
pp. 208-211
Author(s):  
Raluca Maria AILENI ◽  
Laura CHIRIAC
Keyword(s):  
Electromagnetic Field ◽  
Electromagnetic Radiation ◽  
Hybrid Composites ◽  
Principal Component ◽  
Advanced Materials ◽  
Electromagnetic Properties ◽  
Plan Selection ◽  
Conductive Yarns ◽  
Window Blinds ◽  
The Military

In the paper are presented several aspects concerning the composed methods for obtaining the materials capable of reducing the electromagnetic field by reflection/absorption. This study offers a structured presentation about advanced materials with electromagnetic properties that can be used to develop screens for electromagnetic attenuation. Besides is presented a factorial plan, selection of the eigenvectors, and analysis based on principal component. The ACP (principal component analysis) could solve the problems in selecting the optimal parameters used in experiments by reducing the complexity of the data and analyzing the variance of the variables from influencing factors. The investigation of the methods for electromagnetic radiation screens development is attractive due to the area of application, such as protection of the electronic designed for hospitals and special applications in the military area and in the field of transport, but also for the protection of the houses required due to the use of electronic devices (phones, PC, TV) involving mobile or Wifi/WLAN networks. In general, for the attenuation of electromagnetic radiation in the home can use paints, curtains, window blinds or carpets made of fabric, knitted or non-woven materials, with conductive yarns, fibers or polymeric film with adequate electroconductive or electromagnetic properties.

scholarly journals Transient electromagnetic radiation of the lithosphere in a seismically active region

2019 ◽  
Vol 127 ◽  
pp. 03006
Author(s):  
Yiyang Luo ◽  
Nguyen Xuan An ◽  
Vladislav Lutsenko ◽  
Vladimir Uvarov
Keyword(s):  
Electromagnetic Field ◽  
Active Region ◽  
Electromagnetic Radiation ◽  
Seismic Waves ◽  
Earth’S Crust ◽  
Schumann Resonance ◽  
Short Term ◽  
Transient Electromagnetic ◽  
Earth's Crust ◽  
High Level

To study the electromagnetic radiation of the lithosphere associated with seismic waves, we used the recordings of the natural electromagnetic radiation obtained under conditions of weak industrial noise and a high level of microseismicity in the ELF-VLF wave bands. It is shown that these data contain information about the surface waves of the Earth’s crust and are accompanied by a frequency close to the first harmonic of the Schumann resonance. The distribution of spikes over thresholds is obtained, which can be indicators of the activity in the processes of the Earth’s crust. The averaged form of the spikes for different components of the electromagnetic field is obtained. Attention is drawn to the differences in the various components of the electromagnetic field and their diurnal differences are analyzed. The possibility of using the approach to predict the short-term movement of the Earth’s crust is considered.

scholarly journals Electromagnetic Radiation from the Geometrical Point of View

2018 ◽  
Vol 186 ◽  
pp. 01002
Author(s):  
Divakov Dmitriy ◽  
Malykh Mikhail ◽  
Tiutiunnik Anastasiia
Keyword(s):  
Electromagnetic Field ◽  
Electromagnetic Radiation ◽  
Coordinate System ◽  
Maxwell's Equations ◽  
Plane Waves ◽  
Geometrical Optics ◽  
Point Of View ◽  
Curvilinear Coordinates ◽  
Point To Point ◽  
The Relationship

The article describes the relationship between the solutions of Maxwell's equations which can be considered at least locally as plane waves and the curvilinear coordinates of geometrical optics. We introduce phase-ray coordinate system for any electromagnetic field if vectors E and H are orthogonal to each other and their directions do not change with time t, but may vary from point to point in the domain G.

A review on the intensification of metal matrix composites and its nonconventional machining

2018 ◽  
Vol 25 (2) ◽  
pp. 213-228 ◽  
Author(s):  
Ashish Kumar Srivastava ◽  
Amit Rai Dixit ◽  
Sandeep Tiwari
Keyword(s):  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Hybrid Composites ◽  
Advanced Materials ◽  
Matrix Composites ◽  
Suitable Material ◽  
Specific Strength ◽  
Wear And Corrosion ◽  
New Generation ◽  
Conventional Machining

AbstractMetal matrix composites (MMCs) are the new-generation advanced materials that have excellent mechanical properties, such as high specific strength, strong hardness, and strong resistance to wear and corrosion. All these qualities make MMCs suitable material in the manufacture of automobiles and aircraft. The machining of these materials is still difficult due to the abrasive nature of the reinforced particles and hardness of MMCs. The conventional machining of MMCs results in high tool wear and slow removal of materials, thereby increasing the overall machining cost. The nonconventional machining of these materials, on the contrary, ensures much better performance. This paper reviews various research works on the development of MMCs and the subsequent hybrid composites and evaluates their performances. Further, it discusses the influence of the process parameters of conventional and nonconventional machining on the performance of MMCs. At the end, it identifies the research gaps and future scopes for further investigations in this field.

scholarly journals HYGIENIC ASSESSMENT FOR THE ELECTROMAGNETIC FIELD'S LEVELS OF ELECTRONIC INFORMATION AND EDUCATIONAL SCHOOLS' ENVIRONMENT

2019 ◽  
pp. 4-8 ◽  
Author(s):  
V.R. Kuchma ◽  
S.V. Sankov ◽  
A.M. Kurgansky
Keyword(s):  
Electromagnetic Field ◽  
General Education ◽  
Electromagnetic Radiation ◽  
Communication Technology ◽  
Technology Use ◽  
Information Communication ◽  
Electronic Information ◽  
Comprehensive Schools ◽  
Permissible Levels ◽  
Ultrahigh Frequencies

Results of the study on hygienic assessment of the electromagnetic field levels of the electronic information-educational schools’ environment showed that the intensity values of the electromagnetic field were within the limits of the permissible levels in conference rooms, in recreation, in canteens, in classrooms and in workplaces of computer and distance-learning rooms. The packages of system units, small servers, microwave ovens, monitors, televisions, laptops, sockets and extension cords were the main sources of electromagnetic radiation in modern comprehensive schools. The values of electromagnetic radiation of ultrahigh frequencies in the general education establishments were within the limits of the maximum permissible levels. We have been developed recommendations for the hygienic safety of the information-communication technology use and the equipment and furniture placement in computer classes of comprehensive schools.

scholarly journals The Effects of Absorbing Materials on the Homogeneity of Composite Heating by Microwave Radiation

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7362
Author(s):  
Betime Nuhiji ◽  
Matthew P. Bower ◽  
William A. E. Proud ◽  
Steven J. Burpo ◽  
Richard J. Day ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Temperature Distribution ◽  
Electromagnetic Radiation ◽  
Heat Distribution ◽  
Temperature Uniformity ◽  
Geometric Complexity ◽  
Uniform Temperature ◽  
Better Regulation ◽  
Absorbing Materials ◽  
Complexity Increase

When cured in a microwave, flat thin composite panels can experience even heat distribution throughout the laminate. However, as load and geometric complexity increase, the electromagnetic field and resulting heat distribution is altered, making it difficult to cure the composite homogeneously. Materials that absorb and/or reflect incident electromagnetic radiation have the potential to influence how the field behaves, and therefore to tailor and improve the uniformity of heat distribution. In this study, an absorber was applied to a composite with non-uniform geometry to increase heating in the location which had previously been the coldest position, transforming it into the hottest. Although this result overshot the desired outcome of temperature uniformity, it shows the potential of absorbing materials to radically change the temperature distribution, demonstrating that with better regulation of the absorbing effect, a uniform temperature distribution is possible even in non-uniform composite geometries.

scholarly journals SPATIO-TEMPORAL STRUCTURE OF CHERENKOV RADIATION EXCITED BY A LASER PULSE IN AN IONIC DIELECTRIC WAVEGUIDE

2021 ◽  
pp. 74-77
Author(s):  
V.A. Balakirev ◽  
P.I. Markov ◽  
I.N. Onishchenko
Keyword(s):  
Electromagnetic Field ◽  
Laser Pulse ◽  
Electromagnetic Radiation ◽  
Frequency Spectrum ◽  
Dielectric Waveguide ◽  
Cherenkov Radiation ◽  
Temporal Structure ◽  
Mode Composition ◽  
Spatio Temporal

The process of excitation of Cherenkov electromagnetic radiation by a laser pulse in an ionic dielectric waveguide, is investigated. The frequency spectrum and mode composition of the Cherenkov radiation are determined. The spatio-temporal structure of the Cherenkov electromagnetic field is obtained and investigated.

scholarly journals Effect of Stripline Number on Resonant Frequency of Hexagonal Split Ring Resonator Metamaterial

2020 ◽  
Vol 9 (1) ◽  
pp. 26-30
Author(s):  
Romi Fadli Syahputra ◽  
Yan Soerbakti ◽  
Riad Syech ◽  
Erman Taer ◽  
Saktioto Saktioto
Keyword(s):  
Electromagnetic Field ◽  
Resonant Frequency ◽  
Ring Resonator ◽  
Negative Refractive Index ◽  
Split Ring Resonator ◽  
Electromagnetic Properties ◽  
Strip Line ◽  
Frequency Range ◽  
Split Ring ◽  
Resonant Frequency Shift

Piranti-piranti elektronik maupun optoelektronik yang efisien dan responsif saat ini tengah masif dikembangkan dalam beragam bentuk dan jenis. Meta-material merupakan rancangan optoelektronik yang unik dengan sifat elektromagnetik yang tidak ditemukan secara alami, salah satunya adalah peristiwa indeks bias negatif. Eksplorasi terhadap banyak ragam struktur metamaterial sangat penting dilakukan untuk mengidentifikasi karakteristik tiap struktur. Salah satu struktur metamaterial yang menarik dikaji adalah bentuk heksagonal. Penelitian ini menginvestigasi karakteristik frekuensi resonan dan distribusi medan elektromagnetik metamaterial split ring resonator heksagonal (SRR-H) yang dikombinasikan dengan stripe line (SL) berupa logam tembaga. Lebih lanjut, jumlah SL divariasikan dari 0 - 5 unit dan disimulasikan dalam medium udara dalam rentang frekuensi 1 – 7,5 GHz. Hasil simulasi menunjukan adanya pergeseran frekuensi resonan untuk tiap penambahan SL dalam rentang frekuensi 4,31 – 5,82 GHz. Sebaran medan listrik cenderung terpusat pada cincin resonator sedangkan medan magnet cenderung terdistribusi pada SL. Desain metamaterial SRR-H dengan 3 SL memberikan respon disipasi energi yang terkecil dengan medan E maksimum 2,59 kV×m-1 dan medan H maksimum 8,69 A×m-1. Desain SRR-H ini cukup potensial untuk diaplikasikan sebagai antena gelombang elektomagnetik yang efisien dan juga sebagai biosensor. Efficient and responsive electronic and optoelectronic devices are currently being massively developed in various forms and types. Metamaterial is a unique optoelectronic design with electromagnetic properties that are not found naturally, one of its properties is a negative refractive index. Exploration of different types of metamaterial structures is very important to identify the characteristics of each structure. One of the interesting metamaterial structures is a hexagonal shape. This research investigates the resonant frequency characteristics and electromagnetic field distribution of split-ring resonator (SRR-H) hexagonal-shaped metamaterial which is combined with the copper stripe line (SL). Furthermore, the number of SL is varied from 0 to 5 units and simulated in the air medium in frequency range of 1 - 7.5 GHz. The simulation results show a resonant frequency shift occurred for each SL combination in the 4.31 - 5.82 GHz frequency range. The distribution of the electric field tends to be concentrated on the resonator while the magnetic field tends to be distributed on the SL. The SRR-H metamaterial with 3 SL provides the smallest energy dissipation response with a maximum E field of 2.59 kV×m-1 and a maximum H field of 8.69 A×m-1. The SRR-H design is potential enough to be applied as an efficient electromagnetic wave antenna and also as a biosensor.Keywords: Metamaterials, SRR-H, strip line, resonant frequency, electromagnetic field

scholarly journals Electromagnetic Properties of Cold-Cure Silicone Mixtures Containing Multi-Walled Carbon Nanotubes

2020 ◽  
pp. 043-046
Author(s):  
A.G. Tkachev ◽  
◽  
N.R. Memetov ◽  
R.A. Stolyarov ◽  
N.A. Chapaksov ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Physical Properties ◽  
Electromagnetic Radiation ◽  
Nanocomposite Materials ◽  
Electromagnetic Properties ◽  
Frequency Range ◽  
Concentration Dependences ◽  
Multi Walled Carbon Nanotubes ◽  
Properties Of Materials ◽  
Walled Carbon Nanotubes

Nanocomposite materials based on a cold-cure silicone mixture containing multi-walled carbon nanotubes were obtained. The concentration dependences of the radio-physical properties of materials were investigated. An increase in the efficiency of shielding electromagnetic radiation in the radio frequency range of wavelengths with increasing concentrations of multi-walled carbon nanotubes up to 10 wt. % was verified.

Programmable Anisotropic Microparticles for Self-Assembly Applications

2014 ◽  
Vol 1622 ◽  
pp. 55-60 ◽  
Author(s):  
Jonathan Liu ◽  
C. Wyatt Shields ◽  
Oluwatosin Omofoye ◽  
Gabriel P. Lopez
Keyword(s):  
Self Assembly ◽  
Sacrificial Layer ◽  
Nile Red ◽  
Deposition Process ◽  
Particle Orientation ◽  
Advanced Materials ◽  
Electromagnetic Properties ◽  
Patchy Particles ◽  
Metal Evaporation ◽  
New Research

AbstractColloids with anisotropic shape and properties can enable the assembly of advanced materials otherwise not attainable by microfabrication. In this study, we present a convenient method using common microfabrication tools to generate a diverse array of non-spherical microparticles with well-defined shapes, sizes, electromagnetic properties for self-assembly applications. Projection photolithography onto SU-8 photoresist enabled the production of large aspect ratio microparticles such as cubes, cuboids, cylinders, hexagonal prisms, and parallelepipeds. We characterized these particles to confirm their anisotropic shape and size monodispersity. Fluorescent stains (e.g., Nile red) were mixed into the photoresist prepolymer to enhance the visualization of particle orientation. Particles designed for passive self-assembly were prepared by conventional photolithographic techniques. Particles designed for active assembly were then decorated with metallic patches in precise locations along the surface (e.g., top, side or multiple sides) using electron beam metal evaporation. This metal deposition process can enable orientational control of particles during their assembly in directed fields. After fabrication, large particles (e.g., 1,000 µm3) were released from the substrate via gentle sheer forces, whereas small particles (e.g., 10 µm3) were released by the dissolution of a sacrificial layer underneath the SU-8. Suspending the particles in water with surfactant (or other suitable solvents) provided amenable conditions for their assembly in static or dynamic systems. These conventional methods have the potential to catalyze new research in the fabrication and assembly of anisotropic patchy particles with controllable properties for the hierarchical development of self-assembled micromirrors, biosensors, and photonic crystals as examples.

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