Now showing items 364-383 of 770

    • Karyotype, Meiosis And Sperm Formation In The Land Snail Macrochlamys Indica 

      El Alfy, Nagla Z. [نجلاء زكي الالفي]; Abdel-Rehim, A. H.; Al-Ali, K. A. ( Qatar University , 1994 , Article)
      Karyotype analysis, meiosis and sperm formation of the land snail Macrochlamys indica collected from different farms of ornamental plants in Doha city of the State of Qatar were investigated. The chromosome number is n=24 ...
    • Khashm Formation, A New Lithostratigraphic Unit Within The Cretaceous Wasia Group Of Arabia 

      El Nakhal, Hamed A. [حامد احمد النخال] ( Qatar University , 1988 , Article)
      The Khashm Formation is introduced as a new lithostratigraphic unit to include the sandstones and shale interbeds which constitute the upper part of the Cretaceous Wasia Group (s. /.) outcropping in central Arabia. It ...
    • Kinetics and Mechanistic Studies of the Bromination of Some Substituted Tetralones, Part 1 

      Dabbagh, Abdul Majeed M. [عبد المجيد الدباغ]; Ayoub, Mikdad T. ( Qatar University , 2000 , Article)
      The rate of bromination of 2-benzal-l-tetralone (II) and its derivatives p-methyl (12), 77-chloro (13), ffi-chloro (14), and p-nitro (15) have been studied in chloroform. The study indicated first order dependence on each ...
    • Krein's Method For Singular Mixed Problems 

      Abdou, M. A.; Ezzeldin, Naglaa Y.; عبده, محمد; عز الدين, نجلاء ( Qatar University , 1993 , Article)
      In this paper, the spectral relations of the Fredholm integral equation of the first kind for the mixed problems with singular kernel are obtained.
    • Krein's method for solving the integral equation of the first kind With logarithmic kernel 

      Abdou, M. A.; El Rahman, R. O. Abd; عبده, محمد عبد الله احمد; عبد الرحمن, ر. و. ( Qatar University , 1993 , Article)
      Consider the Fredholm's integral equation of the first kind with logarithmic kernel K(IXI) = (- In Ixl. The aim of this paper is to establish the equivalence of Krein's method of solving the equation with the following ...
    • Late Maastrichtian And Paleocene Calcareous Nannofossils From Ain Dabadib Section, Nw Kharga Oasis, Egypt 

      Bassiouni, M. A. [محمد الامين بسيوني]; Sharaby, S.; Faris, M. ( Qatar University , 1991 , Article)
      On terms of calcareous nannofossils, the late Maastrichtian and Paleocene sediments were subdivided into several biozones. The Cretaceous-Tertiary boundary is marked by a hiatus concerning the latest Maastrichtian and the ...
    • Lead-Induced Malformations and Kidney Destruction of Developing Chick Embryos 

      El Shabaka, H. A. [حمزة احمد الشبكة]; Abu-Sinna, G.; Al-Henzab, N. ( Qatar University , 1993 , Article)
      Two doses of lead nitrate, 0.5 and 0.1 mg/egg, were injected into the eggs after 3 days of indubation. Lead nitrate increased mortality rate and decreased the body weight of developing embryos. The lead nitrate also decreased ...
    • Light Microscopic Study On Schistosoma Mansoni Induced Hepatic And Splenic Lesions Following Praziquantel Treatment 

      El Wakf, Azza Mohamed; El Seddik Othman, Abo Baker ( Qatar University , 1989 , Article)
      Hepatic and splenic lesions were developed in mice of both sexes following their exposure to cercariae of Schistosoma mansoni (70 cercariae / animal). After 12 weeks of infection, the liver showed the formation of typical ...
    • The Likelihood Function For A Progressive Disease Model With A Bivariate Survival Function 

      Kittani< Hilmi F. [حلمي كتانة] ( Qatar University , 1995 , Article)
      A model for the natural history of a progressive disease is developed. The model has three disease states and can be expressed as the joint distribution of two survival random variables. Covariate information is incorporated ...
    • Lineament Analysis Of Qatar Peninsula Based On Landsat Imagery 

      El Kassas, I. A. [ابراهيم علي القصاص]; Ashour, M. M. ( Qatar University , 1990 , Article)
      Photo-interpretation of Landsat MSS images of Qatar Peninsula reveals several surface lineaments of different types, extentions and trends. Some of these photo-lineaments are of structural nature while others represent ...
    • Liquid chromatographic separation of the enantiomers of racemic A aminophosphonates as their n-3, 5-dinitrobenzoyl derivatives On chiral fluorocarbinol stationary phases 

      Selim, Adel I. [عادل ابراهيم سليم] ( Qatar University , 1994 , Article)
      The enantiomers of a wide variety of a-aminoaryl (or alkyl) phosphonate esters are separated by liquid chromatography as their N-3,5-dinitrobenzoyl derivatives on three chiral fluorocarbinol stationary phases. In addition ...
    • A List of Marine Algae from Seashores of Iran (Hormozgan Province) 

      Sohrabipour, J.; Rabii, R. ( Qatar University , 1999 , Article)
      Seashores of Hromzgan province in south of Iran were studied for collection and recogna-tion of algal flora (1991-1996). 150 species of marine algae were recognized, including 36 Chlorophyta (16 new). 33 Phaeophyta (15 ...
    • Lithofacies and depositional environments Of the lower jurassic sediments In central Saudi Arabia 

      Al-Saad, Hamad A.; Hewaidy, Abdel-Galil A. ( Qatar University , 1999 , Article)
      The lithofacies, microfacies and sedimentary environments of the surface Lower. Jurassic sediments in central Saudi Arabia are studied. The Lower Jurassic is represented by the marine clastic Marrat Frormation which is ...
    • Lower Eocene Black Shale Beds Of Rus Formation In North Of Oman-Possible Oil Shales 

      Al Hajari, S. A. [سيف علي الحجري]; Khaled, K. A. ( Qatar University , 1994 , Article)
      A suite of samples from some black shale beds of lower Eocene Rus Formation from north of Oman have been investigated through detailed geochemical analyses. The obtained results indicate that these shale beds contain a ...
    • Lumping Processes of Periodic ARMA Processes 

      Smadi, Abdullah A. [عبد الله الصمادي] ( Qatar University , 2004 , Article)
      In this article various lumping processes are defined for periodic ARMA (PARMA) processes, namely, the forward, the backward and the cyclic lumping processes. The inter-relations between the parameters of these lumping ...
    • Magnetic Studies on High - Tc Bi - Pb- Sr - Ca - Cu - O Ceramics 

      Al Hawery, A. S. [عبد العزيز الهويري] ( Qatar University , 1997 , Article)
      The superconducting material with a nominal composition BiI 6 Pb0 4 Sr2 Ca2 Cu3 Ox has been recently synthesized and characterized by the authors using the Q- factor method. The Q-factor data reported in this work shows ...
    • Mangrove As A Bioindicator For Environmental Pollution In The Coastal Marine Environments-Review 

      Sadooni, Fadhil N. [فاضل السعدوني]; El-Kassas, Ibrahim A. ( Qatar University , 1999 , Article)
      Mangrove stand components have been used widely as bioindicators for different types of environmental pollution including heavy metals, organic pollutants and hydrocarbons as as well as in the detection of ozone depletion ...
    • Marine Algae As Bioindicators Of Pollution Levels In The Arabian Gulf 

      Kureishy, Tariq W.; Abdel-Moati, M. A. R.; Al-Muftah, A. R. ( Qatar University , 1995 , Article)
      The extensive distribution of several marine macroalgal species makes them a potential bioindicator tool for monitoring existing levels of different types of marine pollutants in the region. The present work illustrates ...
    • The marine Mollusca of the Qatari waters, Arabian Gulf 

      Al Khayat. J. L. [جاسم عبد الله الخياط] ( Qatar University , 1997 , Article)
      The species composition of the mollusca community in the Qatari waters of the Arabian Gulf, is reported. Data were obtained from analysis of samples collected during 1996 - 1997. A total of 246 species were recorded, ...
    • A Markov Chain Model For River Flow 

      Salim, A. J. [عبد الغفور جاسم سالم]; Thanoon, B. Y. ( Qatar University , 1996 , Article)
      This paper is concerned with a trinary transformation of river flow. The transformed flow is modeled as a three-states Markov chain and both upcrossing and downcrossing problems are studied simultaneously. The stationary ...