Alternative source models of very low frequency events

Frequency of Thyroid Function Disorders among a Population of Very-Low-Birth-Weight Premature Infants

Background: Thyroid function disorders, particularly congenital hypothyroidism (CHT), are important endocrine dysfunctions associated with permanent morbidities. CHT is more prevalent among preterm low-birth-weight neonates compared to term infants with normal weight. Methods: This prospective cohort study was conducted on 126 very-low-birth-weight (VLBW) neonates referred to the neonatal inten...

Programmable, very low noise current source.

We propose a new approach for the realization of very low noise programmable current sources mainly intended for application in the field of low frequency noise measurements. The design is based on a low noise Junction Field Effect Transistor (JFET) acting as a high impedance current source and programmability is obtained by resorting to a low noise, programmable floating voltage source that al...

High‐latitude geomagnetically induced current events observed on very low frequency radio wave receiver systems

[1] Noise burst events observed at Sodankylä, Finland, in the frequency range 20–25 kHz during January–April 2005 last up to 4 s, occur more often at midnight, are associated with high geomagnetic activity, and exhibit a quasi‐constant amplitude perturbation ∼15 dB above the background noise levels. We considered the possibility that the events could be caused by lightning noise breakthrough. T...

Very-low-frequency saucers observed on DEMETER

Localization of Low-frequency Source Current Distributions

Electromagnetic (EM) noise field distributions measured externally around electrical and electronic equipment have been used for localization and identification of the noise sources inside the equipment. For high frequencies (more than hundreds of MHz), the EM sources at finite distances have been localized by applying the techniques such as MUSIC [1], SPM [2], and holographic imaging [3], to t...