نتایج جستجو برای: radiofrequency fields

تعداد نتایج: 262715  

Journal: :Reviews on environmental health 2016
Sarah J Starkey

The Advisory Group on Non-ionising Radiation (AGNIR) 2012 report forms the basis of official advice on the safety of radiofrequency (RF) electromagnetic fields in the United Kingdom and has been relied upon by health protection agencies around the world. This review describes incorrect and misleading statements from within the report, omissions and conflict of interest, which make it unsuitable...

2009
S. D. Anghel T. Frentiu

This paper attempts to give a short overview of atmospheric pressure plasmas generated in very non-uniform radiofrequency electric fields. All these forms of gas discharges have a common characteristic: they are generated based on the possibility to obtain very high voltages in resonant series RLC circuits. The paper presents both the radiofrequency generators designed in this aim and some appl...

Journal: :Neuropsychologia 2006
Vanessa Keetley Andrew W Wood Jo Spong Con Stough

The effect of electromagnetic fields from digital mobile phones (DMP) on cognitive functioning is an area receiving increased attention. This study compares the performance of 120 volunteers on 8 neuropsychological tests during real or sham exposure to a DMP set to maximum permissible radiofrequency power output. When results were adjusted for known covariates (gender, age, or education), sever...

2004
Henry Lai

Nonionizing electromagnetic fields (EMF) have photon energy less than 10eV, a level not sufficient to produce ions by ejection of orbital electrons from atoms. The biological effects of two types of nonionizing electromagnetic fields are being studies intensely: extremely-lowfrequency (ELF) electromagnetic field and radiofrequency radiation. Extremely-low-frequency EMF covers the frequency rang...

2008
M. J. Madsen W. K. Hensinger

We describe a novel high aspect ratio radiofrequency linear ion trap geometry that is amenable to modern microfabrication techniques. The ion trap electrode structure consists of a pair of stacked conducting cantilevers resulting in confining fields that take the form of fringe fields from parallel plate capacitors. The confining potentials are modeled both analytically and numerically. This io...

Journal: :CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne 1999
G B Biederman V A Davey

1. Limits of exposure to radiofrequency fields at frequencies from 10 kHz – 300 GHz: safety code 6 Ottawa: Department of National Health and Welfare; 1991. Cat. no H46-2/90-160. Available: www.hc-sc.gc.ca/rpb 2. Environmental health criteria 137: electromagnetic fields (300 Hz – 300 GHz). Geneva: World Health Organization; 1993. Also available from the Canadian Public Health Association, 400–15...

Journal: :Physical chemistry chemical physics : PCCP 2013
C J Wedge Jason C S Lau Kelly-Anne Ferguson Stuart A Norman P J Hore Christiane R Timmel

The purported effects of weak magnetic fields on various biological systems from animal magnetoreception to human health have generated widespread interest and sparked much controversy in the past decade. To date the only well established mechanism by which the rates and yields of chemical reactions are known to be influenced by magnetic fields is the radical pair mechanism, based on the spin-d...

2008
Eugenia Cabot Andreas Christ Niels Kuster

A numerical study of the induced fields and specific absorption rate (SAR) in anatomical phantoms exposed to the radiofrequency (RF) fields of magnetic resonance (MR) scanners was conducted using the finite difference time domain (FDTD) method at 64MHz and 128MHz. Three phantoms including two adults and one child were used. The study revealed inconsistencies between the MRI safety standards and...

Journal: :Magnetic resonance in chemistry : MRC 2012
Nikolaus M Loening Barth-Jan van Rossum Hartmut Oschkinat

In nuclear magnetic resonance spectroscopy, experimental limits due to the radiofrequency transmitter and/or coil means that conventional radiofrequency pulses ("hard pulses") are sometimes not sufficiently powerful to excite magnetization uniformly over a desired range of frequencies. Effects due to nonuniform excitation are most frequently encountered at high magnetic fields for nuclei with a...

2006
O. Vainio C. J. Vale M. J. Davis N. R. Heckenberg H. Rubinsztein-Dunlop

We experimentally investigate the outcoupling of atoms from Bose-Einstein condensates using two radiofrequency rf fields in the presence of gravity. We show that the fringe separation in the resulting interference pattern derives entirely from the energy difference between the two rf fields and not the gravitational potential difference between the two resonances. We subsequently demonstrate ho...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید