Search results for "fields"

Bio-electromagnetic Numerical Modeling for Health Diagnostics

Mobile phone and auditory system: update

2009

The aim of this study is to asses the non-thermal effects of the electromagnetic fields generated by 915 MHz GSM cellular phones on the human cochlear activity using transient evoked otoacoustic emissions (TEOAE). The study was carried on 205 young and healthy volunteers (age 18-30 years) with normal hearing which were randomly divided into two samples consisting of 85 (Gcase) and 120 (Gcontrol) respectively. The first one was exposed to genuine 10 minutes of GSM electromagnetic fields while the second, undergone sham exposure, was considered as control group for the statistical investigations. All the participants were blind to the genuine or sham exposure. The TEOAEs were measured in the …

EPIDEMIOLOGICAL STUDIES ON POSSIBLE LONG-TERM EFFECTS OF EXTREMELY LOW FREQUENCIES ELECTRICAL AND MAGNETIC FIELDS

2008

Shade effects on overseeded bermudagrass athletic fields: I. Turfgrass coverage and growth rate

2019

Shade from athletic stadium structures can be a significant deterrent to turfgrass performance. The objective of this study was to determine the daily light requirements of an overseeded or non-overseeded bermudagrass (Cynodon spp.) turf maintained to simulate an athletic field. An experiment was established in 2013 on a mature bermudagrass [Cynodon dactylon (L.) Pers. cv. Riviera] turf that was either overseeded with perennial ryegrass (Lolium perenne L.) or non-overseeded. Plots were re-seeded with ryegrass each fall, but ryegrass was allowed to transition without chemical removal. Shade structures were installed to create four light level treatments including a full-sun control (0% shade…

Axisymmetric simulations of magnetorotational core collapse: approximate inclusion of general relativistic effects

2006

We continue our investigations of the magnetorotational collapse of stellar cores discussing simulations performed with a modified Newtonian gravitational potential that mimics general relativistic effects. The approximate TOV potential used in our simulations catches several features of fully relativistic simulations quite well. It is able to correctly reproduce the behavior of models which show a qualitative change both of the dynamics and the gravitational wave signal when switching from Newtonian to fully relativistic simulations. If this is not the case, the Newtonian and the approximate TOV models differ quantitatively. The collapse proceeds to higher densities with the approximate TO…

On the Origin of Asymmetries in Bilateral Supernova Remnants

2007

AIMS: We investigate whether the morphology of bilateral supernova remnants (BSNRs) observed in the radio band is determined mainly either by a non-uniform interstellar medium (ISM) or by a non-uniform ambient magnetic field. METHODS: We perform 3-D MHD simulations of a spherical SNR shock propagating through a magnetized ISM. Two cases of shock propagation are considered: 1) through a gradient of ambient density with a uniform ambient magnetic field; 2) through a homogeneous medium with a gradient of ambient magnetic field strength. From the simulations, we synthesize the synchrotron radio emission, making different assumptions about the details of acceleration and injection of relativisti…

Post-adiabatic supernova remnants in an interstellar magnetic field: oblique shocks and non-uniform environment

2018

Monthly notices of the Royal Astronomical Society 479(3), 4253 - 4270 (2018). doi:10.1093/mnras/sty1750

Nuclear Magnetic Resonance for Cultural Heritage

2007

Abstract Nuclear magnetic resonance (NMR) portable devices are now being used for nondestructive in situ analysis of water content, pore space structure and protective treatment performance in porous media in the field of cultural heritage. It is a standard procedure to invert T 1 and T 2 relaxation data of fully water-saturated samples to get “pore size” distributions, but the use of T 2 requires great caution. It is well known that dephasing effects due to water molecule diffusion in a magnetic field gradient can affect transverse relaxation data, even if the smallest experimentally available half echo time τ is used in Carr–Purcell–Meiboom–Gill experiments. When a portable single-sided N…

Multiple Canard Cycles in Generalized Liénard Equations

2001

AbstractThe paper treats multiple limit cycle bifurcations in singular perturbation problems of planar vector fields. The results deal with any number of parameters. Proofs are based on the techniques introduced in “Canard Cycles and Center Manifolds” (F. Dumortier and R. Roussarie, 1996, Mem. Amer. Math. Soc., 121). The presentation is limited to generalized Liénard equations εx+α(x, c)x+β(x, c)=0.

The polarimetric and helioseismic imager on solar orbiter

2020

This paper describes the Polarimetric and Helioseismic Imager on the Solar Orbiter mission (SO/PHI), the first magnetograph and helioseismology instrument to observe the Sun from outside the Sun-Earth line. It is the key instrument meant to address the top-level science question: How does the solar dynamo work and drive connections between the Sun and the heliosphere? SO/PHI will also play an important role in answering the other top-level science questions of Solar Orbiter, as well as hosting the potential of a rich return in further science. SO/PHI measures the Zeeman effect and the Doppler shift in the FeI 617.3nm spectral line. To this end, the instrument carries out narrow-band imaging…