Search results for "blue"
showing 10 items of 487 documents
The Star Population of Young Open Clusters: A Photometric and Spectroscopic Study
2003
I have determined physical parameters (interstellar reddening, distance, and age) for three young open clusters: h Persei, x Persei, and NGC 1893. I have studied their massive star populations and their formation epochs. I present photometric data for 350 stars in the double open cluster h and x Persei. For both clusters, the distance moduli and reddening are determined to be the same: V0 M p V and E(b y) p . However, the ages for 11.6 0.2 0.42 0.2 the clusters are different. Most stars in h Persei follow the isochrone, although some of the massive stars seem log t p 7.3 younger. By contrast, the stars in x Persei better fit isochrones for (A. Marco & G. Bernabeu 2001, A&A, log t p 7.10–7.1…
X-ray variability of Pleiades late-type stars as observed with the ROSAT-PSPC
2003
We present a comprehensive analysis of X-ray variability of the late-type (dF7-dM) Pleiades stars, detected in all ROSAT-PSPC observations; X-ray variations on short (hours) and medium (months) time scales have been explored. We have grouped the stars in two samples: 89 observations of 42 distinct dF7-dK2 stars and 108 observations of 61 dK3-dM stars. The Kolmogorov-Smirnov test applied on all X-ray photon time series show that the percentage of cases of significant vari- ability is quite similar on both samples, suggesting that the presence of variability does not depend on mass for the time scales and mass range explored. The comparison between the Time X-ray Amplitude Distribution functi…
Discussion – Periodic variations and asteroseismology of active OB stars
2010
AbstractWe summarize the discussion held after the session on periodic variations and asteroseismology. The session not only included seven talks, but as well thirty excellent posters were shown. It was impossible to summarize all these in the available frame of a discussion, and so this work focuses on very few sub-topics only mentioned in the actual discussion session. These topics were the relation of pulsation and turbulence, pulsation in close binaries, the observed photometric variability, the connection of pulsations and outburst, and bipolar flows.
Full Wave Solution for Intel CPU With a Heat Sink for EMC Investigations
2010
A CPU with a heat sink (e.g. Intel Pentium 4 and Intel Pentium dual core) is a challenging problem for EMC analysis. A Very Large Scale Integrated (VLSI) device was modelled using the Finite Element Method (FEM) frequency domain solver to obtain a 3D full wave solution. The electromagnetic (EM) radiation emitted from these high power microelectronic circuits connected to a heat sink was found to have resonant frequencies around 2.4 GHz and 5 GHz with reflection coefficients less than -19 dB and -8 dB respectively. These resonant frequencies are very close to the operating frequency of both IEEE and Bluetooth wireless communication systems. This paper proposes a new benchmark model based on …
Lithium in the intermediate age cluster NGC 3680: Following Li evolution along the C-M diagram
2001
We present an analysis of high resolution spectroscopic observations (R 30 000, S=N =6 0 150) of 24 members of the intermediate age (1.5 Gyr) open cluster NGC 3680, covering all regions of the cluster colour-magnitude (C{M) diagram where cluster members are known to exist. These observations represent in many aspects challenges to our understanding of stellar interior and mixing. Four main sequence G stars have, within the errors, the same Li abundance, 0.3 dex lower than similar stars in the1 Gyr younger Hyades but comparable with those observed in the coeval cluster IC 4651. The cluster shows a clear Li-dip located around the turn-o; two stars on the upper part of the turn-o are out of th…
Human Figure Recognition and the Estimation of its Direction
2006
This work describes a method used to recognize a person situated in indoor environments. It estimates the direction in which the person is turned. The position coordinates are known to the system thanks to localization techniques that use Bluetooth technology. The utilization of such information in intelligent environments allows the execution of actions that interact with the customer. The paper focuses on our human figure recognition technique, which uses image analysis to calculate the direction angle a person is turned towards. Figure recognition is accomplished by comparing the colours of the body parts that mark it out, such as: hair colour, face colour, and clothes colour. The calcul…
Effects of UV and Blue Light on the Bipotential Changes in Etiolated Hypocotyl Hooks of Dwarf Beans
1980
One of the most complex topics to study in biology is the ability of organism to perceive, code, transmit, and integrate environmental information, which is used to direct the cellular metabolism and developmental processes occurring. The detection of different wavelengths of light by specific mechanism plays a key role in plant development. Although great progress has been made in the study of plant photoreceptor pigments, some pigment systems are understood better than others.
The Innervation of Taste Buds in the Soft Palate of the Rat as Revealed by Methylene Blue Staining.
1996
Light microscopic data on the innervation of taste buds in the soft palate of the rat obtained by methylene blue (MB) supravital staining are presented here for the first time. The taste pore including subpopulations of taste bud cells and nerve fibers were stained. Intragemmal nerve fibers were detected ascending up to the taste pore; this suggests the possibility of additional paracellular pathways in taste transduction directly via nerve fibers. Moreover, relatively large bulbous or laminar enlargements of the intragemmal nerve fibers were found. The branches of these nerve fibers, showing minute spiny protuberances, appeared to anastomose. Some perigemmal nerve fibers were also seen in …
Cationic polyaspartamide-based nanocomplexes mediate siRNA entry and down-regulation of the pro-inflammatory mediator high mobility group box 1 in ai…
2015
Abstract High-mobility group box 1 (HMGB1) is a nonhistone protein secreted by airway epithelial cells in hyperinflammatory diseases such as asthma. In order to down-regulate HMGB1 expression in airway epithelial cells, siRNA directed against HMGB1 was delivered through nanocomplexes based on a cationic copolymer of poly(N-2-hydroxyethyl)- d,l -aspartamide (PHEA) by using H441 cells. Two copolymers were used in these experiments bearing respectively spermine side chains (PHEA-Spm) and both spermine and PEG2000 chains (PHEA-PEG-Spm). PHEA-Spm and PHEA-PEG-Spm derivatives complexed dsDNA oligonucleotides with a w/w ratio of 1 and higher as shown by a gel retardation assay. PHEA-Spm and PHEA-P…
An unexpected biomaterial against SARS-CoV-2: Bio-polyphosphate blocks binding of the viral spike to the cell receptor.
2021
Graphical abstract