The halogen gas inside a halogen lamp causes the evaporated tungsten to redeposit on the filament. This process, along with high pressure inside the capsule, slows down deterioration of the filament, improves lumen maintenance and extends the lampâs service life.
The mean heart rate as obtained in this study (246 beats min â1, with a range of 207â314 beats min â1) is within the range given by several authors in chicken embryos. In a previous study () we reported heart rate values ranging between 250 and 270 beats min â1 on days 19 and 20 of incubation.
A normal fetal heart rate (FHR) usually ranges from 120 to 160 beats per minute (bpm) in the in utero period.It is measurable sonographically from around 6 weeks and the normal range varies during gestation, increasing to around 170 bpm at 10 weeks and decreasing from then to around 130 bpm at term.lthough in the healthy fetus the heart rate is usually regular, a beat-to-beat variation of approximately 5 to 15 beats per minute can be allowed.