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At least 1,297 records · Page 72Linked to original sources
PubMed2000

Orthogonality relation for a three-dimensional scattering electromagnetic field in a dispersive medium.

Considering a scattering field by a perfectly conducting sphere as a typical example, we develop a method to derive an orthogonality relation for a three-dimensional scattering electromagnetic field in a dispersive dielectric medium. Each orthogonal mode is composed of the doublet of the incident plane field and the scattering spherical plane field. The scattering field includes the near field in the vicinity of the scatterer. Expanding the total field energy stored in the whole space using the derived orthogonality relation, we show that the total field energy is expressed as the sum of the energies of independent harmonic oscillators.

Journal Article↗
PubMed1975

Orientation of gull chicks exposed to project Sanguine's electromagnetic field.

Birds tested on clear days in the normal geomagnetic field showed a significant clustering of headings about a predicted bearing corresponding with the direction of migration. Individuals tested when a large antenna was energized dispersed randomly. Magnetic fields associated with such conductors may be sufficient to confuse orienting birds.

Animals↗
PubMed1977

Orientation of Euglena gracilis by electromagnetic fields: theory and experiment.

Computer data derived from theoretical treatments of the orientation of ellipsoidal particles in alternating fields is compared with experimental data from microscopic studies on Euglena gracilis, and elongated free-living flagellate. Computed data based upon a theoretical treatment by SAITO, SCHWAN and SCHWARZ showed good agreement with experimental results, predicting the relationship between cellular orientation, the frequency of the impressed field, and the conductivity of the suspending medium.

Computers↗
PubMed2002

Electromagnetic field calculations for an irregularly shaped, near-spheroidal particle with arbitrary illumination.

A spheroidal coordinate separation-of-variables solution has been developed for the determination of the internal, near-surface, and far-scattered electromagnetic fields for irregularly shaped elongated (prolatelike) and irregularly shaped flattened (oblatelike) particles with arbitrary monochromatic illumination. Calculated results are presented, for both plane-wave and focused-Gaussian-beam illumination, which demonstrate the effects of particle geometry on the internal, near-surface, and far-scattered-field distributions.

Journal Article↗
PubMed1990

Prenatal exposure to a low-frequency electromagnetic field demasculinizes adult scent marking behavior and increases accessory sex organ weights in rats.

Pregnant Sprague-Dawley dams were exposed to a low-level, low-frequency pulsed electromagnetic (EM) field (15 Hz, 0.3 msec duration, peak intensity 8 gauss) for 15 min twice a day from day 15 through day 20 of gestation, a period in development that is critical for sexual differentiation of the male rat brain. No differences in litter size, number of stillborns, or body weight were observed in offspring from field-exposed dams. At 120 days of age, field-exposed male offspring exhibited significantly less scent marking behavior than controls. Accessory sex organ weights, including epididymis, seminal vesicles, and prostate, were significantly higher in field-exposed subjects at this age. However, circulating levels of testosterone, luteinizing hormone, and follicle-stimulating hormone, as well as epididymal sperm counts, were normal. These data indicate that brief, intermittent exposure to low-frequency EM fields during the critical prenatal period for neurobehavioral sex differentiation can demasculinize male scent marking behavior and increase accessory sex organ weights in adulthood.

Analysis of Variance↗