Browse 6,486 peer-reviewed studies on electromagnetic field health effects from 4 research libraries.
Showing 1,318 studies matching "radiofrequency"
Peter A. Neukomm · 1976
Most telemetry equipment operates between 10 and 1000 MHz with radiated power from a few microwatts to approximately 2 W. Hot spots in animal brains show heating potential 10 to 15 times higher than predicted by the RAC method.
Unknown authors · 1976
The review assessed human vulnerability, protection materials, and methods for military operations, using sources up to October 1975. It examined biological effects of radiofrequency and microwave radiation up to 300,000 megahertz, including both thermal and nonthermal effects. The review noted that Communist research relied heavily on animal and in vitro studies of systems such as blood, cardiovascular, and nervous systems, and that Communist exposure standards were more stringent than Western standards.
Richard H. Lovely, Thomas J. Sparks, A.W. Guy · 1976
Neil T. Larsen · 1976
Researchers developed a new DC-substitution RF power meter that is not a form of Wheatstone bridge. The instrument allows four-terminal measurement of bolometer resistance and provides improved accuracy and lower noise at lower cost. Servo system measurement errors are typically less than 0.01 percent. Performance testing showed a standard deviation of about 0.008 percent over 1024 random measurements.
Norbert N. Hankin et al. · 1976
Researchers analyzed environmental radiofrequency and microwave radiation from high-power sources including satellite communication earth terminals, radars, and broadcast transmitters. Considering factors such as number of sources, potentially exposed persons, and operating procedures, they concluded broadcast transmitters constitute the most environmentally significant source category. For non-occupational individuals at closest approach distances, anticipated power densities were generally below the 10 mW/cm² occupational threshold. Radar time-averaged power densities were two to four orders of magnitude below peak values due to pulsing, and rotating antennas reduced exposure further.
Arthur W. Guy, Michael D. Webb, John A. McDougall · 1976
Stewart J. Allen et al. · 1976
Terry O. Steiner · 1975
The system provides continuous monitoring of pacemaker output and simulates normal cardiac activity at the pacemaker leads using fiber optics for electrical isolation. The monitor presents a resistive load of approximately 1000 ohms that drops to about 500 ohms when the LED fires during a pacemaker pulse. The entire system was successfully tested at 26.6 MHz and near RF emitters from 200 to 3000 MHz, and the simulator addition did not affect the pacemaker threshold.
Paul S. Ruggera · 1975
Stewart J. Allen et al. · 1975
Researchers calculated and measured radiofrequency power absorption from 10 to 50 MHz in prolate spheroid phantoms and live monkeys. Monkey orientation affected absorption, with monkeys on their sides absorbing more power than on their backs for cross and magnetic polarization.
P. S. RAI, H. J. BALL, S. O. NELSON, L. E. STETSON · 1975
In mating combinations that included a treated male, females laid significantly fewer eggs than in combinations with a treated female, and egg production decreased with longer exposure times. Hatch percentages did not differ significantly across any mating combination. Progeny of RF-treated adults laid far fewer eggs (142.9 vs 296.9) but had similar hatch rates (71.0% vs 77.7%). Adults emerging from RF-treated larvae also laid fewer eggs (81.1-98.1 vs 154.4) with no significant difference in hatch percentages.
James H. Merritt, James W. Frazer · 1975
Mice were exposed to 19 MHz radiofrequency radiation and then euthanized by microwave-heating brain inactivation. There were no significant differences in any neurotransmitters or metabolites when microwave controls were compared to either the E-field or H-field groups. Microwave controls had significantly higher brain content of 5-hydroxyindole acetic acid, serotonin, norepinephrine, and dopamine than conventional controls.
Charles A. Cody et al. · 1975
Researchers used a custom Raman spectrometer assembled by Block Engineering personnel to obtain Raman spectra. Infrared spectra were recorded on a Digilab FTS-15 Fourier transform spectrophotometer. The program established that biological materials do damage when exposed to RF radiation and that molecular spectroscopy methods yield data needed to generate RF radiation hazard parameters. Raman spectroscopy encountered fluorescence and sensitivity problems, while infrared techniques appeared satisfactory from preliminary data but the effect of water-rich background matrices and the ability to do micro-damage assessment were not completely known.
O. P. Gandhi · 1975
Experiments using a parallel plate waveguide measured RF absorption in rats and biological-phantom prolate spheroids across frequencies and polarizations. The results correlated well with free-space irradiation findings. Peak absorption occurred when the electric field was parallel to the long body axis at frequencies where the body length was about one-quarter wavelength, with absorption 2.5 to 3.5 times the shadow cross-section.
D. L. Conover et al. · 1975
Mickey GH, Heller JH, Snyder E · 1975
Andrija Puharich · 1974
C. C. Johnson, T. C. Rozzell · 1974
O. P. Gandhi · 1974
At resonance, absorption was an order of magnitude greater for vertical polarization (electric field along the long axis) than for horizontal or longitudinal orientations. For a human-like aspect ratio of 5.795, temperature increase was 10 times greater for vertical than for horizontal exposure. Extrapolation yielded maximum absorption frequencies for humans of 40–55 MHz for vertical orientation and 135–165 MHz for the other two orientations. Below resonance, prolate spheroids absorbed considerably more in vertical than horizontal orientation, with longitudinal absorption only slightly higher than horizontal.
Z. V. Gordon, Editor · 1974
Unknown authors · 1974
The publishers announced that Biophysik would continue from Volume 114 in 1974 under the new title Radiation and Environmental Biophysics. The journal's scope includes biophysics of nonionizing radiations such as microwaves and radio waves. The journal will also cover biological effects of physical factors and biophysical aspects of environmental research.
Richard Aztell, John C. Nelson · 1974
P. S. RAI, H. J. BALL, S. O. NELSON, L. E. STETSON · 1974
Three-day postemergence adult mealworm beetles were exposed to continuous-wave 39-MHz RF electric fields at 2.5 kV for 4.0 seconds. In ovarian tissue, trophocyte disintegration and vacuole formation appeared at 3 days post-treatment and increased by 6 days with most germarium cells disintegrated. Oocytes from treated adults stained darker and germinal vesicles showed clear areas not seen in controls at 6 days post-treatment.
Gandhi OP · 1974
Researchers used a parallel-plate waveguide to measure RF absorption in rats and phantom bodies across 285 to 4000 MHz. The waveguide results agreed well with free-space irradiation measurements. The El4 orientation (electric field along the major length) was the most absorbing, while the A14 orientation was the least absorbing, and the k14 orientation was only slightly more absorbing than A14. In rats, peak absorption frequencies decreased with increasing body weight, with maximum absorption at 1217, 1020, 900, and 760 MHz for 96-, 158-, 261-, and 390-g animals respectively. Waveguide absorption measurements were in quantitative agreement with behavioral experiments showing shorter work-stoppage times at frequencies with higher absorption.
LT T. Moslak, USNR-R · 1974