RESUMEN
Two different laser phase noise measurement techniques are compared. One of these two techniques is based on a conventional and low-cost delay line system, which is usually set up for the linewidth measurement of semiconductor lasers. The results obtained with both techniques on a high-spectral-purity laser agree well and confirm the interest of the low-cost technique. Moreover, an extraction of the laser linewidth using computer-aided design tools is performed.
RESUMEN
Concentrations of 222Rn in produced water, crude oil, natural gas (NG) and natural gas liquids (NGL) in on-shore Algeria were measured using scintillation cell techniques (Lucas cells) and electret ion chamber (EIC). The first method, active, is based on the use of a Lucas-type scintillation chamber in conjunction with a portable monitor (model Pylon AB-5); the second method, passive, using an EIC with a 4 l glass analysis bottle. The activities of 222Rn were in the range of 0.98-18.50 Bq/l for produced water, 0.02-0.3 Bq/g for crude oil, 40-1000 Bq/m(3) for NG and 300-2500 Bq/m(3) for NGL, respectively. These values are compared with concentrations reported for other countries.
