Now showing items 849-868 of 2240

    • Proton And Carbon-13 Nuclear Magnetic Resonance Of Some 4-Amino-3-Alkyl (Aryl)-5-Thio-1,2,4-Triazolines And Their Derivatives 

      El Toukhy, Ahmed [احمد الطوخي]; Al-Kubaisi, Abdulla H.; Kenawy, Ibrahim ( Qatar University , 1991 , Article)
      The proton and carbon-13 NMR spectra of some 4-amino-3-alkyl(aryl)-5-thio-1,2,4-triazolines, some 3-alkyl-5-thio- 1,2,4-triazolines and some 4-amino-3-aryl-5-thio-l,2,4-triazoles were measured in DMSO-d6 as solvent. The ...
    • Pullulan production from sugar beat molasses 

      Kassim, Mohammad Bashir Ismail [محمد بشيراسماعيل قاسم]; Sultan, Raad Hussani ( Qatar University , 1997 , Article)
      Sugar beet molasses was used as the substrate for the production of pullulan with Aureobasidum pullulans ATCC 42023. In addition biomass, residual sugar and final pH of the culture medium were investigated. In comparing ...
    • The Pulse of Colour: in Virginia Woolf's 'To the Lighthouse' 

      McCarthy, Shaun ( Qatar University , 1979 , Article)
    • Pyrolysis Kinetics of Oil-Palm Solid Waste 

      Mohd Din, Azam T.; Hameed, Bassim H.; Ahmad, Abdul Latif ( Qatar University , 2005 , Article)
      Pyrolysis of oil-palm shells, a cheap and abundantly available solid waste from palm oil producing process, was carried out using thermogravimetric analysis. The effect of heating rates (10,15,20 and 25°C/min) on the kinetic ...
    • Pyrrolizidine alkaloids from alkanna orientalis (L.) Boiss 

      Hammouda, F. M. [فايزة محمود حمودة]; Ismail, S. I.; Hassan, N. M.; Tawfiq, W. A.; Kamel, A. ( Qatar University , 1992 , Article)
      Three pyrrolizidine alkaloids; 7-angelyl retronecine (I), 9-angelyl retronescine (II), and dihydroxytriangularine (III) were isolated by DCCC and VLC from Alkanna orientalis growing in Egypt. Their structures were elucidated ...
    • Pyrrolizidine alkaloids from heliotropium arbainense and h. Ovalifolium 

      Rizk, A. M. [عبد الفتاح محمد رزق]; Hammouda, F. M.; Hassan, N. M. ( Qatar University , 1991 , Article)
      Investigation of the pyrrolizidine alkaloids of Heliotropium arbainense resulted in the isolation and identification of heliotrine, europine and 7-angelylheliotrine. From H. ovalifolium three alkaloids were isolated: ...
    • Pyrrolizidine Alkaloids From Senecio Aegyptius L. 

      Rizk, A. M. [عبد الفتاح محمد رزق]; Hammouda, F. M.; Ismail, S. I.; Hassan, N. M. ( Qatar University , 1988 , Article)
      Investigation of the alkaloidal constituents of Senecio aegyptius L. resulted in the isolation and identification of senecionine, dehydrosenkirkine and probably an isomer of seneciphylline. TLC, HPLC and GLC showed the ...
    • Qualitative And Quantitative Assessment Of Drained Water From Urban Ground-Water 

      Al Hajri, Mohd. M.; Shadid, Fawzi T.; Al-Hajri, Khalid; Ahmed, Shamim ( Qatar University , 1992 , Article)
      Although the groundwater table in the State of Qatar peninsula is reducing, there is a persistent increasing level of groundwater in some areas in Doha city. This increasing tendency could be attributed to the topography ...
    • A Qualitative And Quantitative Survey On The Helminth Parasites Of Fishes From The Aswan High Dam Lake In Egypt 

      Soud, M.F.A. [محمد فتحي عبد الفتاح سعود]; Wannas, M. Q. A. ( Qatar University , 1984 , Article)
      The present investigation is concerned with a helminthological survey of 19 species of fish collected along different seasons from the Aswan High Dam Lake in the southernmost part of Egypt. 615 out of 850 fish (72.4%) are ...
    • A Qualitative Approach to Direct Inference Principle 

      Khayata, Mohamed Yasser [محمد ياسر خياطة] ( Qatar University , 2002 , Article)
      In this paper,we study the suitability of a symbolic model of syllogistic reasoning and direct inference principle with the representation and the management of knowledge based on statistical information and evaluated in ...
    • Qualitative Assessment Of Bottled Water In The Middle East 

      Ahmad, S; Saleem, Abdul ( Qatar University , 1996 , Article)
      Many brands of bottled water are being produced in the Middle East including the Gulf Cooperation Council (GCC) countries. Over fourteen brands of bottled water could be found in the market of Doha. Use of bottled water ...
    • Qualitative Dealing with Quantified Assertions 

      Khayata, Mohamed Yasser [محمد ياسر خياطة]; Jaam, Jihad Mohamad; Garcia, Laurent; Pacholczyk, Daniel ( Qatar University , 2002 , Article)
      In this paper we present a newapproach to a symbolic treatment ofquan-tified statements having the following form "Q A's are 5's", knowing that A and B are labels denoting sets,and Q is a linguistic quantifier interpreted ...
    • Rainfall Characterization In An Arid Area 

      Bazaraa, A. S.; Ahmed, Shamim ( Qatar University , 1991 , Article)
      The objective of this work is to characterize the rainfall in Doha which lies in an arid region. The rainfall data included daily rainfall depth since 1962 and the hyetographs of the individual storms since 1976. The ...
    • A Random Binary Trees Generation Method 

      Maghrabi, Saud M.A. [سعود محمد عبد الله مغربي] ( Qatar University , 2000 , Article)
      There are two widely used random distributions on binary trees, namely the binary search tree distribution and the uniform distribution. By analyzing the performance of algorithms that manipulate binary trees generated at ...
    • Random Distributed Algorithms For Clock Synchronization 

      Nakai, Shoichiro ( Qatar University , 1992 , Article)
      This paper proposes clock synchronization algorithms based on the idea in which randomly chosen m out of the total N processors cooperate to perform the clock adjustment of all processors in a distributed system. Selection ...
    • A Rational Exponential Model for Unconstrained Non-Linear Optimization 

      Al Mashhadany, Huda Khalil [هدى خليل المشهداني] ( Qatar University , 2002 , Article)
      In this Paper, a new algorithm based on the non-quadratic model is suggested for solving unconstrained optimization problems which modifies the classical conjugate gradiant methods. This technique has the same properties ...
    • A rational logarithmic model for unconstrained non-linear optimization 

      Mohamed, H. K. [هدى محمد]; Al Assady, Nidhal H. ( Qatar University , 1997 , Article)
      A new non-quadratic model is proposed for solving unconstrained optimisation problems which modifies and develops the classical conjugate gradient methods. The technique has the same properties as the classical conjugate ...
    • Rayn formation, a new name for the permian khuff formation (S. S.) In saudi arabia 

      El Nakhal, Hamed A. [حامد احمد النخال] ( Qatar University , 1991 , Article)
      The rank of the Khuff Formation (late Carboniferous-late Permian) in Saudi Arabia is raised to group status and it is divided into Unayzah (late Carboniferous-early Permian) and Rayn (middle-late Permian) Formations. The ...
    • Recent Advances In Coring And Core Analysis Technology New Technique To Improve Reservoir Evaluation 

      Al Saddique, M.A; Hamada, G. M.; Al-Awad, M. N. ( Qatar University , 2000 , Article)
      The main goal of core analysis is to reduce uncertainty in reservoir evaluation by providing data representative of the reservoir at in situ conditions. Basic core analysis measurements are unchanged, but advances in core ...
    • Recent Benthic Foraminifera from the Local Water of Qatar, Arabian Gulf 

      Al Hitmi, Hind Hitmi [هند هتمي الهتمي] ( Qatar University , 2000 , Article)
      ABSTRACT In the present study, fifty species of Foraminifera are identified from the bottom sediments of the local Qatari waters on the eastern and northern sides of Qatar Peninsula in the Arabian Gulf. These comprise 7 ...