New BVR light curves of the eclipsing binary system NSV 5904 have been constructed based on CCD o... more New BVR light curves of the eclipsing binary system NSV 5904 have been constructed based on CCD observations obtained using 1.88-m telescope of Kottamia observatory during the phase of telescope testing and adjusting its optical quality on May, 2009. New times of minima and epoch have been determined from these light curves. Using the Binary Maker 3.0 (BM3) package, a preliminary determination of the photometric orbital and physical parameters of NSV 5904 are given.
The deformation potential in x Nb2O5 - (1-x) TeO2, 0.1 PbO - x Nb2O5 - (0.9-x) TeO2 and 0.2 PbO -... more The deformation potential in x Nb2O5 - (1-x) TeO2, 0.1 PbO - x Nb2O5 - (0.9-x) TeO2 and 0.2 PbO - x Nb2O5 - (0.8-x) TeO2 tellurite glass systems, was calculated using the Central Force Theory (CFT). Analysis of the compositional dependence of the experimental deformation potential in the three glass systems has been achieved. The quantitative analysis was based on the number of oxygen atoms that vibrate in the double well potential, the deformation potential and the mutual potential energy according to (CFT) with longitudinal elongation. Comparisons between the previous measured values and the predicted values using the Artificial Neural Network (ANN) model for 11 different tellurite glass compositions have been implemented which showed good agreement between them.
A summary is given in some details on the Alawy Stellar CCD Photometry (ASCCDP) method suggested ... more A summary is given in some details on the Alawy Stellar CCD Photometry (ASCCDP) method suggested by ([1], Paper I). The method has been investigated looking for its limitations. Some modifications have been proposed to assign the detection threshold by the user. Stellar image simulation has been invoked to test the method capability for recognising close stellar images. It has been realised that the method is able to identify correctly images of two stars whose separation is equal to the Rayleigh resolving limit. Lower than this limit the method can recognise stars with acceptable accuracy under certain condition.
New BVR light curves of the eclipsing binary system NSV 5904 have been constructed based on CCD o... more New BVR light curves of the eclipsing binary system NSV 5904 have been constructed based on CCD observations obtained using 1.88-m telescope of Kottamia observatory during the phase of telescope testing and adjusting its optical quality on May, 2009. New times of minima and epoch have been determined from these light curves. Using the Binary Maker 3.0 (BM3) package, a preliminary determination of the photometric orbital and physical parameters of NSV 5904 are given.
The deformation potential in x Nb2O5 - (1-x) TeO2, 0.1 PbO - x Nb2O5 - (0.9-x) TeO2 and 0.2 PbO -... more The deformation potential in x Nb2O5 - (1-x) TeO2, 0.1 PbO - x Nb2O5 - (0.9-x) TeO2 and 0.2 PbO - x Nb2O5 - (0.8-x) TeO2 tellurite glass systems, was calculated using the Central Force Theory (CFT). Analysis of the compositional dependence of the experimental deformation potential in the three glass systems has been achieved. The quantitative analysis was based on the number of oxygen atoms that vibrate in the double well potential, the deformation potential and the mutual potential energy according to (CFT) with longitudinal elongation. Comparisons between the previous measured values and the predicted values using the Artificial Neural Network (ANN) model for 11 different tellurite glass compositions have been implemented which showed good agreement between them.
A summary is given in some details on the Alawy Stellar CCD Photometry (ASCCDP) method suggested ... more A summary is given in some details on the Alawy Stellar CCD Photometry (ASCCDP) method suggested by ([1], Paper I). The method has been investigated looking for its limitations. Some modifications have been proposed to assign the detection threshold by the user. Stellar image simulation has been invoked to test the method capability for recognising close stellar images. It has been realised that the method is able to identify correctly images of two stars whose separation is equal to the Rayleigh resolving limit. Lower than this limit the method can recognise stars with acceptable accuracy under certain condition.
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Papers by Yosry A Azzam