scholarly journals The first study of 54 new eccentric eclipsing binaries in our Galaxy

2018 ◽  
Vol 619 ◽  
pp. A85 ◽  
Author(s):  
P. Zasche ◽  
M. Wolf ◽  
R. Uhlař ◽  
P. Cagaš ◽  
J. Juryšek ◽  
...  

We present an analysis of the apsidal motion and light curve parameters of 54 never-before-studied galactic Algol-type binaries. This is the first analysis of such a large sample of eccentric eclipsing binaries in our Galaxy, and has enabled us to identify several systems that are worthy of further study. Bringing together data from various databases and surveys, supplemented with new observations, we have been able to trace the long-term evolution of the eccentric orbit over durations extending back up to several decades. Our present study explores a rather different sample of stars to those presented in the previously published catalogue of eccentric eclipsing binaries, sampling to fainter magnitudes, covering later spectral types, sensitive to different orbital periods with more than 50% of our systems having periods longer than six days. The typical apsidal motion in the sample is rather slow (mostly of order of centuries long), although in some cases this is less than 50 yr. All of the systems, except one, have eccentricities less than 0.5, with an average value of 0.23. Several of the stars also show evidence for additional period variability. In particular we can identify three systems in the sample, HD 44093, V611 Pup, and HD 313631, which likely represent relativistic apsidal rotators.

Author(s):  
Chaithra. H. U ◽  
Vani H.R

Now a days in Wireless Local Area Networks (WLANs) used in different fields because its well-suited simulator and higher flexibility. The concept of WLAN  with  advanced 5th Generation technologies, related to a Internet-of-Thing (IOT). In this project, representing the Network Simulator (NS-2) used linked-level simulators for Wireless Local Area Networks and still utilized IEEE 802.11g/n/ac with advanced IEEE 802.11ah/af technology. Realization of the whole Wireless Local Area Networking linked-level simulators inspired by the recognized Vienna Long Term Evolution- simulators. As a outcome, this is achieved to link together that simulator to detailed performances of Wireless Local Area Networking with Long Term Evolution, operated in the similar RF bands. From the advanced 5th Generation support cellular networking, such explore is main because different coexistences scenario can arise linking wireless communicating system to the ISM and UHF bands.


2013 ◽  
Vol 8 (15) ◽  
pp. 33-40
Author(s):  
Javier Enrique Arévalo Peña

En la planeación de las próximas generaciones de redes inalámbricas es importante contar con estudios de radio propagación que permitan establecer diseños adecuados para ofrecer los servicios proyectados por las nuevas tecnologías a los usuarios móviles. En este artículo se presentan aspectos relacionados con el comportamiento de cobertura de radio propagación del modelo propuesto por el 3GPP (3rd Generation Partnership Project) para un entorno urbano en una red LTE (Long Term Evolution) empleando sistemas de antenas convencionales y sistemas de antena adaptativas (AAS). Para ello se utiliza la herramienta de software ICS Designer y se establece como escenario los alrededores la Fundación Universidad Autónoma de Colombia ubicada en el centro urbano de la ciudad de Bogotá D. C.


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