Now showing items 161-180 of 2240

    • New Potassium/Argon Ages For The Volcanic Rocks Of Halul Island (Qatar) 

      Meneisy, M. Y. [محمد يسري منيسي] ( Qatar University , 1988 , Article)
      The only rocks of igneous origin known to be exposed in Qatar are those of Halul and Shra'Auh Islands. They occur within a salt diapir and the age of these rocks is uncertain. They have generally been assigned to the Hormuz ...
    • The effect of two substituents on different organoselenides and tellurides to form new charge-transfer complexes 

      Abid, Khalid Y.; Tahir, A. R. ( Qatar University , 2004 , Article)
      Different organotellurides and selenides were prepared as electron donors and reacted with p-Benzoquinone (p-BQ) and m-Dinitrobenzene (m-DNB) as electron acceptors . The resulted molecules were considered as new ...
    • Calculation Of Mass Yield Distributions In Fission Induced By High Energy Protons 

      Issa, M. R. [محمد راغب عيسى]; Abul-Magd, A. Y. ( Qatar University , 1991 , Article)
      An analytical expression is obtained for the mass-yield distribution in fission induced by high-energy protons, using a two-step model. In the first step, the incident proton penetrates the target nucleus, knocking out ...
    • A Special System Of Boundary Value Problems 

      Mohamed, M. I [محمد ابراهيم محمد] ( Qatar University , 1987 , Article)
      In this paper we introduce a special system of boundary value problems and give a method for solving it. Then we give a detailed application of this method to a system of boundary value problems of Hilbert type.
    • The Reproducing Capacity of Gamma Irradiated Adults of Trogoderma Versicolor (Creutz) 

      Abdel Kawy, F. K.; Hasaballa, Z. A.; عبد القوي, فايزكمال; حسب الله, زكريا عبد السلام ( Qatar University , 1993 , Article)
      Male and female, Trogoderma versicolor (Creutz.) were irradiated by gamma radiation as newly emerged adults (12-24 hrs. after emergence). Males required higher doses than females to be sterilized and the reproductive ...
    • Improvement Of The Piecewise Approximation Methods 

      Rababah, A. [ا . ربايه] ( Qatar University , 1996 , Article)
      A piecewise approximation method is described for planar curves. The order of classical piecewise approximations is improved. The method exploits the freedom in the choice of the parametrization and rises the approximation ...
    • On 2n+L-Vertex-Free Graphs 

      Al Wahabi, Kais [قيس الوهابي] ( Qatar University , 1983 , Article)
      We shall introduce the concepts of pseudoadjacent, pseudocoatraction and pseudoho-momorphism. We shall show, with the help of these concepts, in theorem 2 that every quadrilateral graph V (which is a 4-vertexgraph) has ...
    • Separation and preconcentration of malathion and azamethiphos by Unloaded polyurethane foams 

      Al Wakil, A. M. [احمد محمد الوكيل]; Farag, A. B.; Yousef, A. M.; Tollan, Kh. A. ( Qatar University , 1994 , Article)
      The feasibility of using unloaded polyether type polyurethahe foams for the extraction and separation of malathion and azamethiphos in batch and column operations has been examined. The effects of pH, ionic strength, shaking ...
    • A New Tetrafluoroborate Liquid Membrane Electrode For Selective Determination Of Boron 

      Hassan, S. S. M. [سعد السيد محمد حسن] ( Qatar University , 1986 , Article)
      The construction and performance characteristics of a new liquid membrane electrode selective for BF^ion are herein described. The electrode incorporates nitron-tetrafluoroborate ion pair complex in nitrobenzene as a liquid ...
    • Indecomposable Representations Of Order Of E6 

      Omar, A. A. H [عبد الرؤوف عمر]; Sidky, F. I. ( Qatar University , 1985 , Article)
      The extended Dynkin diagram is a valued graph. We are going to construct a Baechstrom order A associateed to Eg. We prove, by constructions, that the order A of infinite lattice-type but can be listed (tame-type), i.e., ...
    • Stable isotopic composition, stoicometry and origin of Siliceous dolomite of naqb siwa member Bahariya oasis, Egypt 

      Holail, Hanafy [حنفي محمود هليل]; Lohmann, K. K. C. ( Qatar University , 1994 , Article)
      The Lower Campanian Naqb Siwa member exposed near Bahariya Oasis, Egypt, is a shoal ing-upward dolomite sequence that hosts chert nodules and lenses and cavity fillings of quartz and calcite. Dolomite is dominantly replacive, ...
    • On Some Shrinkage Techniques For Estimating The Parameters Of Exponential Distribution 

      Yousef, M. A. Q. [م . ع. يوسف]; Ali, M. A.; Abu-Salih, M. S. ( Qatar University , 1986 , Article)
      A variety of shrinkage methods have been proposed for estimation of some unknown parameter by considering estimators based on a prior guess of the value of the parameter. We compare some of the shrunken estimators for the ...
    • Possible Ionic Effects of NaCl on Two Mexican Wheat Cultivars 

      Yasseen, B.T. [بسام طه ياسين] ( Qatar University , 2005 , Article)
      The effect of NaCl on growth and physiology of two Mexican wheat (Triticum asestivum L) cultivars (Cajeme: salt tolerant, and Yecora: salt sensitive) was compared with that of other osmotic agents, Na2SOa (ionic compound) ...
    • Chromite Enrichment in the Recent Fluviatile Sediments, North Iraq 

      Al Juboury, Ali I. [علي اسماعيل الجبوري]; Ismail, Sabah A.; Ghazal, Mohsin M. ( Qatar University , 1999 , Article)
      The Recent sediments from North Iraq are characterized by a higher content of chromite. This paper deals with the mineralogy and geochemistry of chromite in the heavy mineral assemblages from Recent fluvial sediments in ...
    • Glaciations In The Arabian Peninsula 

      El Nakhal, Hamed A. [حامد احمد النخال] ( Qatar University , 1990 , Article)
      Glaciations affected the Arabian Peninsula three times. This was during the Late Ordovician, the Late Carboniferous-Early Permian, and the Pleistocene. Recorded evidence of Paleozoic glaciations in Arabia, includes tillites, ...
    • Prediction Intervals For Future Sample Mean From Inverse Gaussian Distribution 

      Abu Salih, M. S.; Al-Battat, Rafiq K.; أبو صالح, محمد صحبي; البطاط, رفيق ( Qatar University , 1991 , Article)
      A random sample Xi, Xz, ..., Xn from Inverse Gaussian distribution I(/x,X) is observed. On the basis of this observed sample a lOOp prediction interval of the mean Y of a future sample Yi, ..., Ym from I(^,^.) has been ...
    • Seismic Risk Evaluation Based on Maximum Likelihood Technique Applied For the Red Sea Region 

      Othman, Adel A. A. [عادل علي علي عثمان] ( Qatar University , 1993 , Article)
      An analysis of the seismic risk is carried out for the Red Sea region for the recorded earthquakes in the area between 1. January 1913 and 31 December 1982. The maximum likelihood method was applied to determine the hazard ...
    • Effect Of Carbon disulphide, Acrylonitrile And Formaldehyde On Egyptian Paddy Grain-Borne Fungi 

      Mazen, M.B. [محمد بهي الدين مازن]; Abdel-Hafez, S. I.; El-Kady, I. A.; El-Maghraby, O. M. O. ( Qatar University , 1988 , Article)
      Fumigation, with various doses of carbon disulphide, acrylonitrile and formaldehyde for 8, 16 and 32 hours, of paddy grains indicate that formaldehyde was more toxic to the fungi than carbon disulphide and acrylonitrile. ...
    • The Backlund Transformation Of A Kp-Like Class Of Nonlinear Partial Differential Equations 

      El Sherbiny, H. M. [حامد مصطفى الشربيني] ( Qatar University , 1996 , Article)
      The Backlund transformation of a class that behaves in a manner similar to that of the Kadometsev-Petviashli is derived via the use of a transformation that couples this class with a modified given class of the same order. ...
    • Scanning electron microscopy on adults of Schistosoma mansoni treated in-vivo with praziquantel and RO-15 (5458). 

      Mohamed, S. H. [شادية ح. محمد]; Fawzi, Samia M. ( Qatar University , 1997 , Article)
      In view of the known relationship between changes in the tegumental surface of schistosomes and the potency of antischistosomal drugs, the present work is done to study the effect of two oral drugs, namely Praziquantel ...