Mathematics, Statistics & Physics: Recent submissions

Now showing items 801-807 of 807

    • Mössbauer effect study of Li21+Me4+Fe63+O122−spinels 

      Saleh, H.A.; El Nimr, M.K.; Nada, N.; Fayek, M. K. ( Baltzer Science Publishers, Baarn/Kluwer Academic Publishers , 1986 , Article)
      Mossbauer effect spectra are obtained for the cubic ferrites Li2 Me Fe6 O12 (where Me4+ is one of the tetravalent elements Ge, Si and Ti) at 78K up to their magnetic transition temperatures. In a rather large temperature ...

    • Application of Homotopy Perturbation Method to Singularly Perturbed Volterra Integral Equations 

      Alnasr, M.H.; Momani, Shaher ( Asian Network for Scientific Information , 2008 , Article)
      In this study, the Homotopy-Perturbation Method (HPM) proposed by J.-H. He is adopted for solving singularly perturbed Volterra integral equations (SVIEs). Three numerical examples are given to demonstrate the effectiveness ...

    • Mössbauer study of ZnxNi5/3−xFe1Sb1/3O4 spinel ferrite 

      El Nimr, M.K.; Saleh, H.A.; Fayek, M. K. ( Springer Verlag , 1985 , Article)
      The antimony substituted nickel ferrite ZnxNi5/3–xFe1Sb1/3O4 with different values ofx are prepared, checked by x-ray and studied with57Fe Mössbauer spectroscopy over a wide temperature range. Characteristic spectra of ...

    • Wireless transmission using cooperation on demand 

      Hasna, M.O.; Kamel, Tourki; Mohamed Slim, Alouini ( Elsevier B.V. , 2009 , Article)
      Mobile users with single antennas can still take advantage of spatial diversity through repetition based cooperative transmission. In this paper, we consider a scheme in which the cooperation is triggered only if the ...

    • The mathematical theory of finite and infinite dimensional topological spaces and its relevance to quantum gravity 

      Marek-Crnjac, L.; Iovane, G.; Nada, S.I.; Zhong, Ting ( Elsevier Ltd , 2009 , Article)
      The present work gives first a review of the mathematical theory of finite and infinite dimensional topological spaces. Subsequently we connect the discussion with E-infinity theory and the theory of partially ordered sets. ...

    • A 6th-order local approximation by a cubic curve 

      Rababah, A.; Ta'ani, A. A. ( Qatar University , 1997 , Article)
      We derive and present a MAPLE program for the construction of a parametric cubic polynomial curve which has sixth-order contract with a given smooth curve at a given point, thus providing a local sixth-order approximation ...

    • Effect of gamma radiation on the morphology and Thermophysical properties of the pollen wall of Phoenix dactylifera L. 

      El-Ghazaly, Gamal; Kassem, M.E. ( Qatar University , 1994 , Article)
      Pollen grains of Phoenix dactylifera were exposed to different doses of gamma radiation (250,500,1000 rad and 1 M rad). To access the effect of radiation on the external morphology of the pollen grains, they were examined ...