An antenna is a structure that is made of material bodies that may consist of either conducting or dielectric materials or may be a combination of both. Such a structure should be matched to the source of the electromagnetic energy so that it can radiate or receive the electromagnetic field in an efficient manner. The interesting phenomenon is that an antenna displays selectivity properties not only in the frequency domain but also in the space domain. In the frequency domain an antenna is capable of displaying an external resonance phenomenon where at a particular frequency the current density induced on it can be suffi- ciently significant to cause radiation of electromagnetic fields from that struc- ture. An antenna also possesses a spatial impulse response that is a function of both the azimuth and elevation angles. Thus, an antenna displays spatial selec- tivity as it generates a radiation pattern that can selectively transmit or receive electromagnetic energy along certain spatial directions in the far field as in the near field even a highly directive antenna has essentially an omnidirectional pat- tern with no selectivity. That is the reason researchers have been talking about space division multiple access (SDMA) where one directs a beam along the direction of the desired user but places a null along the direction of the unde- sired user. This has not materialized as we shall see in the next chapter as most of the base station antennas operate in the near field of an antenna. As a receiver of electromagnetic field, an antenna also acts as a spatial sampler of the electro- magnetic fields propagating through space. The voltage induced in the antenna is related to the polarization and the strength of the incident electromagnetic fields. The objective of this chapter is to illustrate how an electromagneticwave propagates and how an antenna extracts the energy from such a wave. In addi- tion, it will be outlined why the antenna was working properly for the last few decades where one could receive electromagnetic energy from the various parts
Menstrual disorders or infertility in female mostly caused by hormonal disturbance. One of the factors which can disturb hormonal system is the electromagnetic waves from cell phone that can increase the free radicals. Tomato and zinc are antioxidants that can inhibit the formation of free radicals. The objective of this experiment is to determine the effect of tomato and zinc combination to the number of female oocytes from white rats Sprague dawley strain induced by electromagnetic waves from mobile phone radiation (SAR=1,56 W/kg). The study uses 25 rats that were divided into 5 groups: no treatment (K1), only induced by electromagnetic waves (K2), 1,85gr tomato and 0,54mg zinc treatment (P1), 3,7gr tomato and 0,27mg zinc treatment (P2), 7,4gr tomato and 0,135mg zinc treatment (P3). The groups were exposed to electromagnetic waves for 2 hours in 30 days. The data were analyzed by using the Post Hoc test. The result is the average number of oocytes obtained in K1 is 66.8; K2 is 42,4; P1 is 61.8; P2 is 64,83; and P3 is 63,2. The conclusion is there is an effect of combination between tomato and zinc to the number of female oocytes from white rats Sprague dawley strain induced by electromagnetic waves of mobile phone radiation.
The quick-tempered growth of telecommunication application in industrial, medical and also military field has led to the high frequency of electromagnetic (EM) wave . This high frequency generated electromagnetic interference (EMI) which may cause disruption in those applications. Therefore, EM wave absorber with the capability of absorbing these unwanted EM signals is invented.
days. On day-31 mice were sacrificed, the spleen was taken and histology preparations were made employing HE staining technique and the diameter of the splenic white pulp was measured. The results showed that the diameter of the splenic white pulp treated mice was significantly (p <0.05) bigger compared to the control mice. This suggested that significant difference was observed between the treatment groups which were all cell phone radiation and the control group, especially in the CDMA. It was concluded that electromagnetic radiation has the potential effect of activating the immune system in the peripheral areas.
One of new culture in our society is using a mobile phone or called handphone in many kind of our activity. It is a very harmfull for human being especially for their health. The high rate of mobile phone use in the community will increase the exposure to electromagnetic waves and can distrub the human brain in its structure, function, and biochemical aspect. The stres induction also affect on memory. The purpose of this study is to determine the effect of mobile phone electromagnetic exposure during 14 days to working memory. The sample of this research are 18 rats (Rattus norvegicus) 2- 3 week-old Sprague dawley strain were divided into 3 different groups: control group (K), 1 hour exposure per day group (P1), and 3 hours exposure per day (P2) which exposed to mobile phone’s electromagnetic waves for 14 days. Evaluating working memory are done with radial arm maze.The average values of working memory’s K: 2%, P1: 1,33%, P2: 2,33%. In One Way ANOVA test, p value is 0,5 (p>0,05). Fourteen days exposure to mobile phone’s electromagnetic waves not affected the working memory on mice (Rattus Norwegicus) Sprague dawley. [JuKe Unila 2015; 5(9):13-17]
Abstract —This paper is concerned with the development of a model-order reduction (MOR) approach for the acceleration of a source-sweep analysis using the volume electric field integral equation (EFIE) formulation. In particular, we address the prohibitive computational burden associated with the repeated solution of the two-dimensional electromagneticwave scattering problem for source-sweep analysis. The method described within is a variant of the Krylov subspace approach to MOR, that captures at an early stage of the iteration the essential features of the original system. As such these approaches are capable of creating very accurate low-order models. Numerical examples are provided that demonstrate the speed-up achieved by utilising these MOR approaches when compared against a method of moments (MoM) solution accelerated by use of the Fast Fourier Transform (FFT).
The frequency dependence of relative permittivity ε (x) and conductivity σ (0) for Magnetic resonance Imaging (MRI) sources . Comparing with this literature, the results obtained from this project shows that if the value of frequency increases, there will be an increase in the conductivity σ (0) and decrease the permittivity ε (x). Therefore by increasing the frequency, it will increase the attenuation and in contrast decrease the skin depth. It will affect the value of electrical field and propagation of the electromagneticwave. The project analysis also proved that MRI exhibit the same scenario as cellular phone and the electromagneticwave could propagate deep into a human skin cell at 2.36GHz. Another comparison with experimentally result which at range 2-3 GHz they have active foreign particle in human cell than others frequency. The particle maybe virus or bacteria and causing the cell damage.
Chapter 2: This chapter discuss about the information that have in project. This chapter discusses more about literature review for the interaction in cell when expose to electromagneticwave. The structure of human cell also will be discussed in this chapter and its function within electromagnetic propagation. Beside that the behaviour and structure of three layers also be mentioned.
sin(kr − ω t + [ ϕ − ϕ ']) tells us that the electromagneticwave propagates outward with the speed of light c (evidence from k = ω /c) from the dipole along the r axis and both electric and magnetic fields are spinning (oscillate with ω rad/s) and orbiting (rotating with ω 0 rad/s) along the r axis. The orbital
The three main parts of WPT is the distance to transfer the power to the intended devices. Short transmission use inductance and inductive coupling to transfer power, while medium transmission use Resonant induction and long range use electromagneticwave power transfer to transfer electrical energy, all of this transmission is without the need of a medium. For radio wave method, this method will send electrical signal by using the radio signal just like WI-FI. Laser method will transmit power that is embedded into the laser beam and the last method is to transfer power by using ultrasonic method that is composed of components that have its own purposes to send and receive the signal and change the signal to DC power.
The Maxwell electromagnetism can be viewed as one of the first theories of a material endowed with a structure (i.e.the electromagnetic fields), although the Maxwell–Faraday’s elec- tromagnetic fields are defined also out of a body of finite extent. As the electromagnetic fields pervade the whole physical space, the mathematical problem for the electromagnetic materials has to be formulated not only in the domain occupied by the body, but also in the exterior do- main, accordingly. The electromagnetic fields obey a set of differential equations that are in general coupled with the mechanical equations [3, 4]. Should the Maxwell equations possibly decouple from the mechanical ones, one could think to solve them first and afterward to look for the associated stress tensor, in order to enquire about the mechanical behaviour of the material.
In this paper, modified F-expansion method has been successfully applied to find the some exact traveling wave solutions of the sixth-order Boussinesq equation. The method is more effective and simple than other methods and a number of solutions can be obtained at the same time. The obtained solutions are presented through the hyperbolic functions and the exponential functions. The obtained results are verified by putting them back into the original equation. Some of our solutions are in good agreement with already published results for a special case. This study shows that the modified F-expansion method is quite efficient and practically well suited for use in finding exact solutions for the nonlinear evolution equation in mathematical physics and engineering sciences.
Light is produced by the energy released when atoms are excited by heat, chemical reaction, or other means. Light is both a wave and a particle, and travels through space as electromagnetic waves. Each “colour” has a unique wavelength due to the wave motion. This wavelength is the distance a wave travels in one cycle. The light wavelength is express in term of nanometers since the wavelengths are short. The color green for the example is the most visible light with the approximate wavelength of 565nm. Light has neither mass nor charge even though it is a wave and a light particle is called a photon is classified as a particle because it is the smallest “piece” of light. This is an analogous to an electron being the smallest negatively charged “piece” of an atom.
It’s well known that two of the most critical problems facing the world today are global warming and high energy consumption. The usage of linear electromagnetic actuators could effectively contribute in reducing the large amount of emissions caused by transportation by implementing the new generations of automobile engines as it contributed in significant energy saving and mechanical wear in many applications. For example Levitated train, the usage of Levitated train introduced three to five times reduction of energy utilized by railroads trains and totally reduced the mechanical wear due to the employment of non- contact new technology.
This research focus on the problem related to wave breaker design at the bottom of the sea which is directed to reduce the impact of the coming wave along the coastal line. These wave breakers, located at the bottom of the sea, functioned as an instrument to decrease the amplitude of the wave moving above them. This result is important to know, to give development direction and model application in the specific study which connect the real condition of abrasion and dissedimentation in the coastal area. The study here is conducted using the analogy of the grating phenomena in the study of optics. Here, two waves modeled are used: linear wave and dispersion wave. For dispersion wave, the model used is the Boussinesq equation with the exact dispersion relation.
In 2002, the AWAC was first released with the Acoustic Surface Tracking option. The vertically oriented transducer in the center of the AWAC could now be used to measure the distance to the sea surface directly by using the simple echo sounder principle. The direct measure (as discussed earlier) has many advantages; the first, and most profound, is that there is effectively no depth limit for coastal waters and that the largest possible portion of the wind wave band is covered. The AST measurement also allows for both time series and spectral analysis. This means design parameters such as H 10 and H max can be measured