scholarly journals Magnetite Particle Presence in the Human Brain: A Computational Dosimetric Study to Emphasize the Need of a Complete Assessment of the Electromagnetic Power Deposition at 3.5 GHz

2021 ◽  
Vol 11 (5) ◽  
pp. 7720-7729
Author(s):  
D. Vatamanu ◽  
S. Miclaus
Keyword(s):  
Human Brain ◽  
Electromagnetic Waves ◽  
Eddy Currents ◽  
Magnetic Losses ◽  
Power Deposition ◽  
Emit Radiation ◽  
Electromagnetic Power ◽  
Communication Devices ◽  
Dosimetric Study ◽  
Portable Communication

The growing evidence of increased magnetite nanoparticles (both endo- and exo-genic) in the human brain raises the importance of assessing the entire power deposition when electromagnetic waves at GHz frequencies propagate in such tissues. This frequency range corresponds to many popular portable communication devices that emit radiation close to a human's head. At these frequencies, the current dosimetric numerical codes can not accurately compute the magnetic losses part. This is due to the lack of an implemented computational algorithm based on solving the coupled Maxwell and Landau-Lifshitz-Gilbert equations, in the case of magneto-dielectrics, considering eddy currents losses and specific properties of magnetic sub-millimetric particles. This paper focuses on analyzing the limits and the inconsistencies when using commercial dosimetric numerical software to analyze the total absorbed power in brain models having ferrimagnetic content and being exposed to 3.5GHz electromagnetic waves. Magnetic losses computed using Polder’s permeability tensor as constitutive relation lead to unreliable results. However, using such software can provide a preliminary view of the electromagnetic impact of ultra- and super-high frequencies on magnetic-dielectric tissues.

Display technologies for portable communication devices

2002 ◽  
Vol 90 (4) ◽  
pp. 581-590 ◽  
Author(s):  
J. Kimmel ◽  
J. Hautanen ◽  
T. Levola
Keyword(s):  
Communication Devices ◽  
Portable Communication

scholarly journals Near-zero-index media as electromagnetic ideal fluids

2020 ◽  
Vol 117 (39) ◽  
pp. 24050-24054
Author(s):  
Iñigo Liberal ◽  
Michaël Lobet ◽  
Yue Li ◽  
Nader Engheta
Keyword(s):  
Optical Interconnects ◽  
Electromagnetic Waves ◽  
Power Flow ◽  
Optical Systems ◽  
Dielectric Particles ◽  
Electromagnetic Power ◽  
Interesting Connection ◽  
Ideal Fluids ◽  
Local Properties ◽  
Zero Index

Near-zero-index (NZI) supercoupling, the transmission of electromagnetic waves inside a waveguide irrespective of its shape, is a counterintuitive wave effect that finds applications in optical interconnects and engineering light–matter interactions. However, there is a limited knowledge on the local properties of the electromagnetic power flow associated with supercoupling phenomena. Here, we theoretically demonstrate that the power flow in two-dimensional (2D) NZI media is fully analogous to that of an ideal fluid. This result opens an interesting connection between NZI electrodynamics and fluid dynamics. This connection is used to explain the robustness of supercoupling against any geometrical deformation, to enable the analysis of the electromagnetic power flow around complex geometries, and to examine the power flow when the medium is doped with dielectric particles. Finally, electromagnetic ideal fluids where the turbulence is intrinsically inhibited might offer interesting technological possibilities, e.g., in the design of optical forces and for optical systems operating under extreme mechanical conditions.

Delegation-based robust authentication model for wireless roaming using portable communication devices

2014 ◽  
Vol 60 (4) ◽  
pp. 668-674 ◽  
Author(s):  
Pardeep Kumar ◽  
Andrei Gurtov ◽  
Jari Iinatti ◽  
Sang-gon Lee
Keyword(s):  
Communication Devices ◽  
Portable Communication

scholarly journals An octa-band planar monopole antenna for portable communication devices

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rezaul Azim ◽  
Touhidul Alam ◽  
Md Sharif Mia ◽  
Ali F. Almutairi ◽  
Mohammad Tariqul Islam
Keyword(s):  
Wireless Communication ◽  
Communication Systems ◽  
Monopole Antenna ◽  
Manufacturing Cost ◽  
Multiple Frequency ◽  
Frequency Bands ◽  
Communication Devices ◽  
Planar Monopole Antenna ◽  
Portable Communication ◽  
Service Bands

AbstractDue to the rapid development of wireless communication systems, good numbers of services and devices use different frequency bands and protocols. To concurrently cover all these services, the antenna in communication devices should operate over multiple frequency bands. The use of wide and multi-band antennas not only reduces the number of antennas necessary to cover multiple frequency bands but also lessens the system complexity, size, and costs. To operate over eight frequency bands to cover sixteen well-established narrow service bands, a planar monopole antenna is proposed for portable communication devices. The proposed antenna is comprised of an inverted F-shaped monopole patch with a rotated L-shaped strip and an F-shaped ground strip with a rotated L-shaped branch. The studied antenna can excite at multiple resonant modes which helps it to achieve eight measured operating bands of 789–921 MHz, 1367–1651 MHz, 1995–2360 MHz, 2968–3374 MHz, 3546–3707, 4091–4405 MHz, 4519–5062 MHz and 5355–6000 MHz. The achieved measured operating bands can cover sixteen popular narrow service bands for 4G/3G/2G, MWT, WiFi, WiMAX, WLAN, and sub-6 GHz 5G wireless communication system. The studied antenna achieved good gain, efficiency and exhibits stable radiation characteristics. Moreover, the antenna does not use any lumped element and left ample space for other circuitries which makes it easier to use in portable devices such as tablets, laptops, etc. with low manufacturing cost.

Integrated image decompression and display driving for portable communication devices using DWTs

2001 ◽  
Author(s):  
Nicholas A. Lawrence ◽  
Tim D. Wilkinson ◽  
William A. Crossland
Keyword(s):  
Communication Devices ◽  
Portable Communication

Consumers' Expectations of the Densities of Portable Communication Devices

1998 ◽  
Vol 42 (6) ◽  
pp. 589-592
Author(s):  
Lydia Volaitis ◽  
Rulie Chou ◽  
Michael Wiklund
Keyword(s):  
Product Quality ◽  
Cell Phones ◽  
Three Dimensional ◽  
Weight Ratio ◽  
Portable Devices ◽  
Communication Devices ◽  
Portable Communication ◽  
Block Models ◽  
Expected Density

Each year, portable devices used for communication seem to be getting smaller and lighter. Presuming that displays will remain legible and buttons can be pressed reliably, continued size reduction seems to be a worthy objective. After all, consumers logically prefer devices that fit in a jacket pocket or pocketbook over those that must be stowed in a briefcase. But, are concomitant weight reductions a good thing? To answer this question, we experimented with three-dimensional, block models of pagers, cell phones, and two-way radios. Specifically, we made five block models of each type of product, varying the weight, and consequently, the density, of each model over a selected range. We asked participants to rate the expected density, durability, and quality of the models, relative to the actual devices. One objective was to see if consumers preferred products with roughly the same density (i.e., volume-to-weight ratio), or if the type of product (i.e., pager, phone, or radio) would lead people to prefer different densities. Another objective was to determine how density influenced perceptions of product quality and durability.

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