Short Time Scale Variation of a Near-Contact Binary System, GR Tauri

2000 ◽  
pp. 211-220 ◽  
Author(s):  
B. Soonthornthum ◽  
Y. Yang ◽  
L. Qingyao ◽  
B. Tanvanichkul
Keyword(s):  
Binary System ◽  
Time Scale ◽  
Short Time Scale ◽  
Contact Binary ◽  
Short Time ◽  
Scale Variation

scholarly journals On the Short Time Scale Evolutionary History of the Contact Binary VW Cephei

1998 ◽  
Vol 11 (1) ◽  
pp. 396-396
Author(s):  
I. Pustylnik
Keyword(s):  
Evolutionary History ◽  
Light Curves ◽  
Published Data ◽  
Short Time Scale ◽  
Flare Activity ◽  
Considerable Portion ◽  
History Of ◽  
Contact Binary ◽  
Elongation Phase ◽  
Short Time

We study the short-time evolutionary history of the well-known contact binary VW Cep. Our analysis is based partly on the numerous UBV lightcurves obtained at Tartu Observatory, IUE spectra, and samples from the published data. Special attention is given to the effects of asymmetry of the light curves. A higher degree of asymmetry outside the eclipses along with the significant displacements of the brightness maxima in respect to the elongation phase is interpreted as evidence that a considerable portion of the flaring source is concentrated close to the neck connecting the components. We discuss the nature of asymmetry in terms of possible mass exchange and the flare activity and compare the results of our model computations with the record of orbital period variations over the last 60 years.

An Alternative Test Using Algal Cultures for Testing Chemicals for Toxicity

1993 ◽  
Vol 21 (2) ◽  
pp. 196-201
Author(s):  
Søren Achim Nielsen ◽  
Thomas Hougaard
Keyword(s):  
Size Distribution ◽  
Mitotic Activity ◽  
Time Scale ◽  
Test System ◽  
Short Time Scale ◽  
Toxic Substances ◽  
Alternative Test ◽  
Short Time ◽  
Algal Cultures ◽  
Test Cultures

An alternative test is presented, in which algal cultures are used for testing toxic substances. This test system is based on variations in the size distribution of cells in test cultures as a measurement of growth. Thus, inhibition of mitotic activity is used as a measurement for toxic effects. The test can be performed on a short time-scale and is very sensitive to even weak toxic doses.

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