A certificate of authenticity (COA) is an inexpensive physical object that has a random unique structure with high cost of near-exact reproduction. An additional requirement is that the uniqueness of COA’s random structure can be verified using an inexpensive device. We propose a design for objects that behave as COAs in the electromagnetic field. The objective is to complement RFIDs so that th...

In this work, we used the finite element method (FEM) and the multiconductor transmission lines (MTL) method for designing an UHF magnetic resonance imaging (MRI) probe. This radio frequency (RF) volume coil quasi-transverse electromagnetic (quasi-TEM) type, based on the use of 16 microstrip transmission line elements has been developed for in vivo hydrogen magnetic resonance (HMR) application ...

Electromagnetic (EM) waves, traditionally used for purposes such as geophysical characterization, impact properties to be measured. This paper describes the effects of radio frequency (RF) waves on hydraulic conductivity glass beads and natural sand. A series tests was conducted using a customized, rigid-wall, cylindrical permeameter inside resonant cavity made Plexiglas covered with electrical...

Trace impurity transport in tokamaks is studied using an electrostatic, collisionless fluid model for Ion-Temperature-Gradient (ITG) and Trapped-Electron (TE) mode driven turbulence in the presence of radio frequency (rf) fields in the ion cyclotron range of frequencies, and the results are compared with neoclassical predictions. Two separate effects of the rf field on ITG/TE-mode stability and...

It is still under debate whether occupational exposure to radio frequency/microwave electromagnetic fields (RF/MW-EMF) contributes to the development of brain tumors. This analysis examined the role of occupational RF/MW-EMF exposure in the risk of glioma and meningioma. A population-based, case-control study including 381 meningioma cases, 366 glioma cases, and 1,494 controls aged 30-69 years ...

This study presents experimental data for the effects of weak radio frequency (RF) magnetic fields on hydrogen peroxide (H2O2) production and cellular growth rates of fibrosarcoma HT1080 cells in vitro. Cells were exposed either to 45 µT static magnetic fields (SMFs)-oriented vertical to the plane of growth or to SMFs combined with weak 5 and 10 MHz RF magnetic fields of 10 µTRMS intensity perp...

In this work, we demonstrate the possibility to modify the electric-field distribution of a radio frequency (RF) coil to generate electric field-free zones in the body without significantly altering the transmit sensitivity. Because implant heating is directly related to the electric-field distribution, implant-friendly RF transmit coils can be obtained by this approach. We propose a linear bir...

In the last twenty years, hundreds of experiments have been carried out on animals to assess cancer-related risks of exposure to extremely-low-frequency (ELF) and radiofrequency (RF) electromagnetic fields. Most of the work has been performed at frequencies related to the generation of electricity at 50/60Hz and mobile telephony at around 1 GHz. Results obtained on cancer-related models are des...

Through experiments and numerical simulations we explore the behavior of rf SQUID (radio frequency superconducting quantum interference device) metamaterials, which show extreme tunability and nonlinearity. The emergent electromagnetic properties of this metamaterial are sensitive to the degree of coherent response of the driven interacting SQUIDs. Coherence suffers in the presence of disorder,...

Free space optics (FSO) is a technology that uses modulated optical beams to transmit information line-of-sight through the atmosphere. To date, the primary focus of FSO research and development has been toward the transmission of digital signals, primarily for “last mile” applications. This paper reports the use of FSO to transport modulated radio frequency (RF) analog signals, together with a...