Electromagnetic Fields and Relative Heating Patterns Due to a Rectangular Aperture Source in Direct Contact with Bilayered Biological Tissue

1971 ◽  
Vol 19 (2) ◽  
pp. 214-223 ◽  
Author(s):  
A.W. Guy
2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Li Gun ◽  
Du Ning ◽  
Zhang Liang

Permittivity of biological tissue is a critical issue for studying the biological effects of electromagnetic fields. Many theories and experiments were performed to measure or explain the permittivity characteristics in biological tissue. In this paper, we investigate the permittivity parameter in biological tissues via theoretical and experimental analysis. Firstly, we analyze the permittivity characteristic in tissue by using theories on composite material. Secondly, typical biological tissues, such as blood, fat, liver, and brain, are measured by HP4275A Multi-Frequency LCR Meter within 10 kHz to 10 MHz. Thirdly, experimental results are compared with the Bottcher-Bordewijk model, the Skipetrov equation, and the Maxwell-Gannett theory. From the theoretical perspective, blood and fat are regarded as the composition of liver and brain because of the high permittivity in blood and the opposite in fat. Volume fraction of blood in liver and brain is analyzed theoretically, and the applicability and the limitation of the models are also discussed. These results benefit further study on local biological effects of electromagnetic fields.


Author(s):  
Ibrahim Dergham ◽  
Yasser Alayli ◽  
Rodrigue Imad ◽  
Yskandar Hamam

In this paper, the authors present an evaluation of the electromagnetic fields generated by a static wireless charging system designed for an electric kick scooter on the human biological tissue. The guidelines on the exposure to the electromagnetic fields are previously specified. In this work, a model is designed under COMSOL multi-physics to study the effects of the magnetic field on two possible body parts of a person, which might be exposed to this field, namely the head and the hands is analysed. The magnetic flux density, the induced electrical field, the specific absorption rate, and the resulting increase of temperature of biological tissues are modelled and compared to the limits and guidelines prescribed in the regulation established to limit the exposure of people to electromagnetic fields. Furthermore, the used wireless charging system is modified to operate at higher frequencies to study its effect. The obtained results are below the guidelines and limits of exposure to the electromagnetic fields specified by the International Commission on Non-Ionizing Radiation Protection, European Commission, Institute of Electrical and Electronics Engineers and International Electrotechnical Commission.


2020 ◽  
Author(s):  
Yuri Vladimirovich Mikhailov ◽  
Alexander Alexandrovich Rukomoinikov ◽  
Rinat Gazizyanovich Abdeev ◽  
Eldar Rinatovich Abdeev

The unevenness of the heat flow generated in the furnaces of the drums of rotary kilns leads to damage to the drum casing, which can cause premature failure. The author suggests that by deflecting the flame by applying electromagnetic fields, it is possible to prevent direct contact between the flame and the furnace drum, extending the latter’s service life. In this way, it is possible to regulate the directions of movement of the heated combustion products to realize the uniform distribution of heat fluxes, as well as to regulate local temperature fields in real time. The study took into account 5 main factors of the influence of the electromagnetic field on the flame. Based on the studies, a description of a device partially integrated in the furnace is proposed. In this case, there is no significant constructive modernization of the furnace. This device is an analogue of a high-temperature fan, but has several advantages in comparison with it. Keywords: electromagnetic field, furnace, flame, heat exchange


Author(s):  
Ling Jun Wang

Recently we have presented a theory of unification of gravitational and electromagnetic fields based on the generalization of Newton’s law to include a dynamic term similar to the Lorentz force of electrodynamics[1]. The unification is convincing. The generalization based on similarity of Newton’s law and Coulomb’s law, however, is speculative although reasonable and compelling. In this article, we have presented a derivation of the dynamic term of gravitation based on our newly proposed ether dynamics, which removes the speculative nature of dynamic term and perfects the unification theory. It turns out that the gravitational interaction is transmitted through the space medium ether. An object in ether is in direct contact with the ether, causing it to move like a highly viscous and incompressible fluid. The movement of ether propagates thorough space like a continuous medium, exerting a force on any object in ether.


1984 ◽  
Vol 75 ◽  
pp. 597
Author(s):  
E. Grün ◽  
G.E. Morfill ◽  
T.V. Johnson ◽  
G.H. Schwehm

ABSTRACTSaturn's broad E ring, the narrow G ring and the structured and apparently time variable F ring(s), contain many micron and sub-micron sized particles, which make up the “visible” component. These rings (or ring systems) are in direct contact with magnetospheric plasma. Fluctuations in the plasma density and/or mean energy, due to magnetospheric and solar wind processes, may induce stochastic charge variations on the dust particles, which in turn lead to an orbit perturbation and spatial diffusion. It is suggested that the extent of the E ring and the braided, kinky structure of certain portions of the F rings as well as possible time variations are a result of plasma induced electromagnetic perturbations and drag forces. The G ring, in this scenario, requires some form of shepherding and should be akin to the F ring in structure. Sputtering of micron-sized dust particles in the E ring by magnetospheric ions yields lifetimes of 102to 104years. This effect as well as the plasma induced transport processes require an active source for the E ring, probably Enceladus.


Author(s):  
T. E. Hutchinson ◽  
D. E. Johnson ◽  
A. C. Lee ◽  
E. Y. Wang

Microprobe analysis of biological tissue is now in the end phase of transition from instrumental and technique development to applications pertinent to questions of physiological relevance. The promise,implicit in early investigative efforts, is being fulfilled to an extent much greater than many had predicted. It would thus seem appropriate to briefly report studies exemplifying this, ∿. In general, the distributions of ions in tissue in a preselected physiological state produced by variations in the external environment is of importance in elucidating the mechanisms of exchange and regulation of these ions.


Author(s):  
K. N. Colonna ◽  
G. Oliphant

Harmonious use of Z-contrast imaging and digital image processing as an analytical imaging tool was developed and demonstrated in studying the elemental constitution of human and maturing rabbit spermatozoa. Due to its analog origin (Fig. 1), the Z-contrast image offers information unique to the science of biological imaging. Despite the information and distinct advantages it offers, the potential of Z-contrast imaging is extremely limited without the application of techniques of digital image processing. For the first time in biological imaging, this study demonstrates the tremendous potential involved in the complementary use of Z-contrast imaging and digital image processing.Imaging in the Z-contrast mode is powerful for three distinct reasons, the first of which involves tissue preparation. It affords biologists the opportunity to visualize biological tissue without the use of heavy metal fixatives and stains. For years biologists have used heavy metal components to compensate for the limited electron scattering properties of biological tissue.


2005 ◽  
Vol 24 (1) ◽  
pp. 2-10 ◽  
Author(s):  
Kenneth F. Taylor ◽  
Nozumu Inoue ◽  
Bahman Rafiee ◽  
John E. Tis ◽  
Kathleen A. McHale ◽  
...  

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