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Electromagnetic Radiation

Ana Marija Marjanovic Cermak, Ivan Pavicic, Ivancica Trosic
The exact mechanism that could explain the effects of radiofrequency (RF) radiation exposure at non-thermal level is still unknown. Increasing evidence suggests a possible involvement of reactive oxygen species (ROS) and development of oxidative stress. To test the proposed hypothesis, human neuroblastoma cells (SH-SY5Y) were exposed to 1800 MHz short-term RF exposure for 10, 30 and 60 minutes. Electric field strength within Gigahertz Transverse Electromagnetic cell (GTEM) was 30 V m(-1) and specific absorption rate (SAR) was calculated to be 1...
November 17, 2017: Journal of Environmental Science and Health. Part A, Toxic/hazardous Substances & Environmental Engineering
Muhammad R A Qureshi, Yasir Alfadhl, Xiaodong Chen, Azadeh Peyman, Myron Maslanyj, Simon Mann
Human body exposure to radiofrequency electromagnetic waves emitted from smart meters was assessed using various exposure configurations. Specific energy absorption rate distributions were determined using three anatomically realistic human models. Each model was assigned with age- and frequency-dependent dielectric properties representing a collection of age groups. Generalized exposure conditions involving standing and sleeping postures were assessed for a home area network operating at 868 and 2,450 MHz...
November 16, 2017: Bioelectromagnetics
Yuzhang Liang, Hui Zhang, Wenqi Zhu, Amit Agrawal, Henri J Lezec, Lixia Li, Wei Peng, Yi Zou, Yan-Qing Lu, Ting Xu
With the development of advanced nanofabrication technologies over the last decade, plasmonic nanostructures have attracted wide attention for their potential in label-free biosensing applications. However, the sensing performance of nanostructured plasmonic sensors is primarily limited by the broad-linewidth features with low peak-to-dip signal ratio in the extinction spectra that result from strong radiative damping. Here, we propose and systematically investigate the in-plane and out-of-plane dipolar interactions in an array of plasmonic nanoring resonators that are from the spatial combination of classic nanohole and nanodisk structures...
November 15, 2017: ACS Sensors
Ege Özgün, Andriy E Serebryannikov, Ekmel Ozbay, Costas M Soukoulis
Combining loss and gain components in one photonic heterostructure opens a new route to efficient manipulation by radiation, transmission, absorption, and scattering of electromagnetic waves. Therefore, loss/gain structures enabling [Formula: see text]-symmetric and [Formula: see text]-broken phases for eigenvalues have extensively been studied in the last decade. In particular, translation from one phase to another, which occurs at the critical point in the two-channel structures with one-dimensional loss/gain components, is often associated with one-way transmission...
November 14, 2017: Scientific Reports
Bart D Wilkison, Emily B Wong
Military pilots may be at greater risk for skin cancer, particularly melanoma. Military-specific studies are limited, but skin cancer rates in civilian pilots and aircrews have previously been examined. Risk factors for all pilots may include exposure to UV radiation (UVR) at higher altitudes, cosmic radiation, and electromagnetic energy from cockpit instruments, as well as altered sleep-wake cycles. The study of aviation-specific risk factors for skin cancer is relevant to all pilots and dermatologists who care for them...
October 2017: Cutis; Cutaneous Medicine for the Practitioner
Le Chang, Yue Li, Yongmin Liu
Efficiently manipulating the polarization states of electromagnetic waves is of great importance for communication, imaging, and sensing. In this paper, we aim to control the circular polarization states, e.g., left-hand, or right-hand, for the bidirectional radiated waves utilizing a pair of back-to-back quarter-wave plates, which are integrated within an ultrathin cavity. As an example, a bidirectional circularly polarized wave with the same helicity in forward and backward is generated based on numerical analyses, and proved by experiments in microwave region...
November 10, 2017: Scientific Reports
Adam Verrender, Sarah P Loughran, Vitas Anderson, Lena Hillert, G James Rubin, Gunnhild Oftedal, Rodney J Croft
The etiology of Idiopathic Environmental Intolerance attributed to Electromagnetic Fields (IEI-EMF) is controversial. While the majority of studies have indicated that there is no relationship between EMF exposure and symptoms reported by IEI-EMF sufferers, concerns about methodological issues have been raised. Addressing these concerns, the present experiment was designed as a series of individual case studies to determine whether there is a relationship between radiofrequency-electromagnetic field (RF-EMF) exposure and an IEI-EMF individual's self-reported symptoms...
November 10, 2017: Bioelectromagnetics
Emma P Mukhokosi, Saluru B Krupanidhi, Karuna K Nanda
We, for the first time, provide the experimental demonstration on the band gap engineering of layered hexagonal SnSe2 nanostructured thin films by varying the thickness. For 50 nm thick film, the band gap is ~2.04 eV similar to that of monolayer, whereas the band gap is approximately ~1.2 eV similar to that of bulk for the 1200 nm thick film. The variation of the band gap is consistent with the the theoretically predicted layer-dependent band gap of SnSe2. Interestingly, the 400-1200 nm thick films were sensitiveto 1064 nm laser iradiation and the sensitivity increases almost exponentiallly with thickness, while films with 50-140 nm thick are insensitive which is due to the fact that the band gap of thinner films is greater than the energy corresponding to 1064 nm...
November 9, 2017: Scientific Reports
Yu N Korolev, L V Mihajlik, L A Nikulina, M S Geniatulina
The experiments on male white rats with the use of biochemical, photo-optical, and electron-microscopic techniques have demonstrated that the use of low-intensity electromagnetic radiation of ultrahigh frequency (EMR UHF) and low-intensity low-frequency magnetic field (MF) during the post-irradiation period (within 21 days after exposure to radiation) enhanced the metabolic and regenerative processes in the testes and liver. It was shown that the application of MF largely intensified the antioxidant activity whereas EMR UHF preferentially stimulated the biosynthetic processes as well as the processes of cellular and intracellular regeneration...
2017: Voprosy Kurortologii, Fizioterapii, i Lechebnoĭ Fizicheskoĭ Kultury
Anna Cifuentes-Rius, Angela Ivask, Shreya Das, Nuria Penya Auladell, Laura Fabregas, Nicholas L Fletcher, Zachary H Houston, Kristofer James Thurecht, Nicolas H Voelcker
Gold nanoclusters (Au NCs) have become a promising nanomaterial for cancer therapy due to their biocompatibility and fluorescent properties. In this study, the effect of ultrasmall protein-stabilized 2 nm Au NCs on six types of mammalian cells (fibroblasts, B-lymphocytes, glioblastoma, neuroblastoma, and two types of prostate cancer cells) under electromagnetic radiation is investigated. Cellular association of Au NCs in vitro is concentration-dependent and Au NCs have low intrinsic toxicity. However, when Au NC-incubated cells are exposed to 1 GHz electromagnetic field (microwave radiation, µW), cell viability significantly decreases thus demonstrating that Au NCs exhibit specific µW dependent cytotoxicity, likely resulting from localized heating...
November 8, 2017: ACS Applied Materials & Interfaces
Thamer S Almoneef, Faruk Erkmen, Omar M Ramahi
We present the idea and design of a dual polarized metasurface for electromagnetic energy harvesting. A 4 × 4 super cell with alternating vias between adjacent cells was designed to allow for capturing the energy from various incident angles at an operating frequency of 2.4 GHz. The collected energy is then channeled to a feeding network that collects the AC power and feeds it to a rectification circuitry. The simulation results yielded a radiation to AC and an AC to DC conversion efficiencies of around 90% and 80%, respectively...
November 7, 2017: Scientific Reports
Ya-Min Wang, Min Pan, Xiang-Yong Liang, Bang-Jing Li, Sheng Zhang
Electromagnetic wave absorption coatings can effectively minimize electromagnetic radiation and are widely used in the military and civil field. However, even small scratches on the coating can lead to a large decline of absorption ability and bring serious consequences. To enhance the lifetime of electromagnetic wave absorbing coating, a kind of self-healing electromagnetic wave absorbing coating is developed by introducing host-guest interactions between the absorbing fillers and polymer matrix. After being damaged, the cracks on this coating can be healed completely with the aid of small amounts of water...
November 2, 2017: Macromolecular Rapid Communications
S J Smartt, T-W Chen, A Jerkstrand, M Coughlin, E Kankare, S A Sim, M Fraser, C Inserra, K Maguire, K C Chambers, M E Huber, T Krühler, G Leloudas, M Magee, L J Shingles, K W Smith, D R Young, J Tonry, R Kotak, A Gal-Yam, J D Lyman, D S Homan, C Agliozzo, J P Anderson, C R Angus, C Ashall, C Barbarino, F E Bauer, M Berton, M T Botticella, M Bulla, J Bulger, G Cannizzaro, Z Cano, R Cartier, A Cikota, P Clark, A De Cia, M Della Valle, L Denneau, M Dennefeld, L Dessart, G Dimitriadis, N Elias-Rosa, R E Firth, H Flewelling, A Flörs, A Franckowiak, C Frohmaier, L Galbany, S González-Gaitán, J Greiner, M Gromadzki, A Nicuesa Guelbenzu, C P Gutiérrez, A Hamanowicz, L Hanlon, J Harmanen, K E Heintz, A Heinze, M-S Hernandez, S T Hodgkin, I M Hook, L Izzo, P A James, P G Jonker, W E Kerzendorf, S Klose, Z Kostrzewa-Rutkowska, M Kowalski, M Kromer, H Kuncarayakti, A Lawrence, T B Lowe, E A Magnier, I Manulis, A Martin-Carrillo, S Mattila, O McBrien, A Müller, J Nordin, D O'Neill, F Onori, J T Palmerio, A Pastorello, F Patat, G Pignata, Ph Podsiadlowski, M L Pumo, S J Prentice, A Rau, A Razza, A Rest, T Reynolds, R Roy, A J Ruiter, K A Rybicki, L Salmon, P Schady, A S B Schultz, T Schweyer, I R Seitenzahl, M Smith, J Sollerman, B Stalder, C W Stubbs, M Sullivan, H Szegedi, F Taddia, S Taubenberger, G Terreran, B van Soelen, J Vos, R J Wainscoat, N A Walton, C Waters, H Weiland, M Willman, P Wiseman, D E Wright, Ł Wyrzykowski, O Yaron
Gravitational waves were discovered with the detection of binary black-hole mergers and they should also be detectable from lower-mass neutron-star mergers. These are predicted to eject material rich in heavy radioactive isotopes that can power an electromagnetic signal. This signal is luminous at optical and infrared wavelengths and is called a kilonova. The gravitational-wave source GW170817 arose from a binary neutron-star merger in the nearby Universe with a relatively well confined sky position and distance estimate...
November 2, 2017: Nature
Daniel Kasen, Brian Metzger, Jennifer Barnes, Eliot Quataert, Enrico Ramirez-Ruiz
The cosmic origin of elements heavier than iron has long been uncertain. Theoretical modelling shows that the matter that is expelled in the violent merger of two neutron stars can assemble into heavy elements such as gold and platinum in a process known as rapid neutron capture (r-process) nucleosynthesis. The radioactive decay of isotopes of the heavy elements is predicted to power a distinctive thermal glow (a 'kilonova'). The discovery of an electromagnetic counterpart to the gravitational-wave source GW170817 represents the first opportunity to detect and scrutinize a sample of freshly synthesized r-process elements...
November 2, 2017: Nature
Mario Kupresak, Xuezhi Zheng, Guy A E Vandenbosch, V V Moshchalkov
Although many commercially available electromagnetic tools are conveniently used in RF and microwave applications, only a few of them provide the capability to analyze the optical response of nanometric radiators and scatterers. The assessment of their performance in the visible to near ultraviolet part of the electromagnetic (EM) spectrum becomes more and more important, considering the exponential rise of nanoscale systems. Since the accuracy of these numerical tools has not been fully investigated in literature, in this paper we essentially demonstrate a comparative study of the most widely used EM field solvers in the area of nano-plasmonics: COMSOL, CST and Lumerical...
October 30, 2017: Optics Express
Peihua Feng, Ying Wu, Jiazhong Zhang
Non-linear behaviors of a single neuron described by Fitzhugh-Nagumo (FHN) neuron model, with external electromagnetic radiation considered, is investigated. It is discovered that with external electromagnetic radiation in form of a cosine function, the mode selection of membrane potential occurs among periodic, quasi-periodic, and chaotic motions as increasing the frequency of external transmembrane current, which is selected as a sinusoidal function. When the frequency is small or large enough, periodic, and quasi-periodic motions are captured alternatively...
2017: Frontiers in Computational Neuroscience
Carlo Bradac, Mattias T Johnsson, Matthew van Breugel, Ben Q Baragiola, Rochelle Martin, Mathieu L Juan, Gavin K Brennen, Thomas Volz
Superradiance (SR) is a cooperative phenomenon which occurs when an ensemble of quantum emitters couples collectively to a mode of the electromagnetic field as a single, massive dipole that radiates photons at an enhanced rate. Previous studies on solid-state systems either reported SR from sizeable crystals with at least one spatial dimension much larger than the wavelength of the light and/or only close to liquid-helium temperatures. Here, we report the observation of room-temperature superradiance from single, highly luminescent diamond nanocrystals with spatial dimensions much smaller than the wavelength of light, and each containing a large number (~ 10(3)) of embedded nitrogen-vacancy (NV) centres...
October 31, 2017: Nature Communications
Anna M Laszlo, Marta Ladanyi, Krisztina Boda, Jozsef Csicsman, Ferenc Bari, Andrea Serester, Zsolt Molnar, Krisztian Sepp, Marta Galfi, Marianna Radacs
Several studies have examined the potential biological effects of electromagnetic fields (EMF) on birds; however, little attention has been paid to the extremely low frequency (ELF; 0-300 Hz; 0-50 μT) radiation found in an urbanized environment. For monitoring the effects of ELF EMF, we used a turkey (Meleagris gallopavo) model, because the nucleated erythrocytes of turkeys contain β-adrenoceptors, and norepinephrine- (NE-) activated β-adrenoceptors have an important role in physiological and behavioral processes...
October 25, 2017: Poultry Science
Yin Zhang, Yijun Feng, Junming Zhao, Tian Jiang, Bo Zhu
Controlling the terahertz wave, especially the dynamical and full control of terahertz wavefront, is highly demanded due to the increasing development of practical devices and application systems. Recently considerable efforts have been made to fill the 'terahertz gap' with the help of artificial metamaterial or metasurface incorporated with graphene material. Here, we propose a scheme to design tunable metasurface consisting of metallic patch array on a grounded polymer substrate embedded with graphene layers to electrically control the electromagnetic beam reflection at terahertz frequency...
October 26, 2017: Scientific Reports
Amirreza Mahigir, Te-Wei Chang, Ashkan Behnam, Gang Logan Liu, Manas Ranjan Gartia, Georgios Veronis
We numerically design and experimentally test a SERS-active substrate for enhancing the SERS signal of a single layer of graphene (SLG) in water. The SLG is placed on top of an array of silver-covered nanoholes in a polymer and is covered with water. Here we report a large enhancement of up to 2 × 10(5) in the SERS signal of the SLG on the patterned plasmonic nanostructure for a 532 nm excitation laser wavelength. We provide a detailed study of the light-graphene interactions by investigating the optical absorption in the SLG, the density of optical states at the location of the SLG, and the extraction efficiency of the SERS signal of the SLG...
October 25, 2017: Scientific Reports
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