Asian Transactions on Basic & Applied Sciences
Volume: 02, Issue: 03, July 2012
Title: Photometric Properties Of Super Hump In Dwarf Novae
Author(s): Wafaa H.Zaki and Arshed A.Alzubaidy
Paper ID: ATBAS-40220025
Pages: 1 - 13
Abstract: The study of the properties of dwarf novae systems is multi-introductory subject. The dwarf novae system can be regarded as stellar variables, which leads to the outbursts model, that is based on four main assumptions, the mass transfer burst, the disk instability, full limit cycle instability and thermal instability. Three dwarf novae have been treated ( WZ-Sge),(SS-Cyg),(Z-Cam). The photometric observations of the dwarf novae systems offer a series of measurements of instantaneous Magnitude of systems at various times. The outburst model is applied and the new parameters have been obtained at the case of super humps through it's period of super outburst (Luminosity, temperature, disk radius & temperature gradient).The resultant values of luminosity and temperature gradients for the previous systems In two cases (outburst and quiescent) is quite close to each other and also the values of masses of the primary star (white Dwarf) are different for each one, the reason is, the mass rate in (WZ-Cge) star system is nearly (0.45 solar mass) and the value of its mass rate is (8.29*1015). In other stars the value of mass rate is little compared with its volume .And has been noted that the temperature of outer edge of accretion disk during the outburst and quiescent case is relatively little compared with the inner edges of accretion disk.
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Title: Evaluation of Environmental Pollution in the Arabian Gulf Coast at the Eastern Province, SA
Author(s): Mohammed A. Zyadah and Mohsin G. Almoteiry
Paper ID: ATBAS-50226038
Pages: 14 - 21
Abstract: Ten sites were selected representing the studied sites of the Arabian Gulf Coast, Eastern Region, SA during October 2010 and February 2011. The mean variations of physico-chemical characteristics in water and sediment were recorded. Most of environmental parameters showed higher concentrations at sites IV and VIII than the other sites. The concentration of heavy metals (Cu, Zn, Pb, Cd and As) in sediment were higher than that recorded in water. Heavy metals concentration in fish was higher than that recorded in both water and sediment. Sites IV and VIII showed the highest values of heavy metals in fish while sites I and II recorded the lowest values. Two species of fish (Rhbdosargus haffara and Liza alata) recorded the higher concentration of heavy metals, but the Scomberomorus commerson showed the lowest accumulation of heavy metals than the other fish. The concentration of heavy metals in fish at the study area is within the allowable limits.
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