HST UV observations of V795 Her reveal a strong 2.6-h orbital variation in the prominent UV lines, in contrast to earlier (IUE) evidence of a 4.8-h period. Only the Civ line contains a strong blue-shifted, wind formed absorption component. Several lines exhibit a 'narrow' absorption feature near rest velocity which may originate in the disk, and a blue-shifted emission feature which accounts fo...

We present results of a detailed analysis of spectral variability observed in the optical spectrum of HD 4004 (WR1). On the basis of data obtained during monitoring of this object on 3 consecutive nights in Dec 1993, and two additional nights in Dec 1994 we show that the variability in He ii λ 5411, C iv λ 5808 and He i λ 5876 may reach as much as 50% in equivalent width. This variability shows...

The evolution of low frequency variability in cerebral blood flow velocity (CBFV) was examined in 30 consecutive admissions of very low birthweight babies. Measurement of CBFV was made on the first day of life and at weekly intervals until discharge. Altogether 133 recordings were subjected to visual classification and described as showing presence or absence of variability at a frequency betwe...

Variable ejection velocity jet models can qualitatively explain the appearance of successive working surfaces in Herbig-Haro (HH) jets. This paper presents an attempt to explore which features of the HH 34 jet can indeed be reproduced by such a model. From previously published data on this object, we find evidence for the existence of a 3-mode ejection velocity variability, and then explore the...

the variability of temperature and precipitation is regarded as one of the main characteristics of the climate.precipitation and its results, especially results such as droughts, vary on different temporal and spatial scales. thepurpose of this paper is to determine the frequency of the inter-annual variability of the driest month in north-westiran. in order to obtain the best results, we used ...