Qatar University Science Journal - [From 1981 TO 2007]: المرسلات الحديثة
السجلات المعروضة 481 -- 500 من 770
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On Existence Of Two Real Periodic Solutions Of Differential Equations Of Riccati Type
( Qatar University , 1986 , Article)In this paper we consider the two equations z^z^p^z+r^t), (*) z^z^ptOz+r^t), (••) where z € C, p, r) and r^ are real, continuous and periodic with period T. It was shown ... -
Mangrove As A Bioindicator For Environmental Pollution In The Coastal Marine Environments-Review
( 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 ... -
Pyrrolizidine alkaloids from heliotropium arbainense and h. Ovalifolium
( 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: ... -
Design And Implementation Of A Microprocessor Controlled Digital Filter
( Qatar University , 1991 , Article)The construction and implementation of a microprocessor controlled real time recursive digital filter have been given. The system designed could also be applied to a variable coefficients system such as ADAPTIVE FILTER and ... -
Gravity investigation for detecting The subsurface basement topography Of the western part of behera Governorate, North Egypt
( Qatar University , 1999 , Article)One of the most effective tools for exploration of the subsurface basement topography is the gravity method. The Bouguer gravity map of the western part of Behera Govemorate west of the Nile Delta of Egypt has been analyzed ... -
Review of the genus polymorphus luhe, 1911 (acanthocephala:polymorphidae), with the synonymization of hexaglandula petrochenko, 1950, and subcorynosoma hoklova, 1967, and a key to the species
( Qatar University , 1992 , Article)The position, concept and composition of the genus Polymorphus (= Profilicollis Meyer, 1931; Falsifilicollis Webster, 1948; Parafincollis Petrochenko, 1950; Subfilicollis Hoklova, 1967) are critically evaluated and a new ... -
Lineament Analysis Of Qatar Peninsula Based On Landsat Imagery
( 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 ... -
Studies on some aspects of antiviral activity. 1-influence of propolis on Newcastle disease virus
( Qatar University , 1994 , Article)The effect of popolis on different-Newcastle disease virus (NDV) vaccinal strains as well as virulent virus were studied. It was clear that the addition of propolis to NDV induced a significant reduction of infectivity ... -
Thermal and Optical Radiation Effects on LEH
( Qatar University , 2003 , Article)Synthetic red blood cells known as LEH is a material that offers an excellent alternative to substitution blood since the chemical composition of the Oxy, LEH, is similar to that of the natural blood cells. Unfortunately, ... -
Pan African Basement Of Bir Safsaf Area East Sahara African Craton
( Qatar University , 1994 , Article)Bir Safsaf area occurs at the extreme southern part of the Western Desert of Egypt. It is covered by the Pan African Basement represented by the old continental gneisses and migmatites comprising granitic, granodioritic ... -
Effect of plastic deformation on Corrosion of cadmium in 0.1 m sodium Sulphate solution
( Qatar University , 1993 , Article)The present investigation was carried out to study the influence of prior plastic deformation and surface finish on the corrosion behaviour of pure cadmium in 0.1 M Na2SC>4 solution at 25° C. Cylindrical specimens were ... -
y - Irradiation Effect On The Ferroelastic High Temperature Phase In LiKSO4 Crystals
( Qatar University , 1992 , Article)The effect of •y -irradiation on the thermodynamic parameters of LiKSC>4 single crystals, in the high temperature range 300-1000 K, is investigated. The results show that T,; as well as Cp decrease with dose rate. However, ... -
Tail Fracture Planes of Autotomy in Geckos
( Qatar University , 1993 , Article)The structure of the tail facture planes was morphologically and histologically studied in two species of geckoid lizards, living in Qatar, Cyrtodactylus scaber and Bunopus tuberculatus. The fracture plane is formed of a ... -
Heterocyclic Aminoacrylate Esters Of Potential Biological Activity
( Qatar University , 1985 , Article)This work describes the synthesis of N-substituted piperidyl 2-benzoxazole acrylates (la-d); 2-benzothiazole acrylates (2a-d); 2-furyl acrylates (3a-d) and 2-thiophene acrylates (4a-d). The esters of 3-quinuclidyl (Ie, 2e, ... -
A Simple Diagram For Gravity Interpretation By Gradients For A Lateral Varying Formation
( Qatar University , 1984 , Article)A simple diagram is constructed for the interpretation of the gravity anomaly arising from a formation of linear density variation. The diagram can be easily used if the horizontal gradient is also known. With the help of ... -
Regenerative abnormalities in hind limbs of bufo regularis induced by repeated amputations: I. Early larval stages
( Qatar University , 1993 , Article)The regenerative response of the hind limbs of early larval stages: 52, 53, 54 and 55 of Bufo regularis was studied following repeated amputations at the ankle level. The pattern of morphogenesis as well as skeletal ... -
Measurements Of Radon Permeability Through Some Membranes
( Qatar University , 1994 , Article)The diffusion of 222Rn through different types of membranes has been studied by an equilibrium method using a Si surface barrier a-detector with a resolution of 14 keV FWHM for ^'Am. The permeability constant for Aluminized ... -
An early marker of monoclonal light chain protein In bladder cancer
( Qatar University , 1994 , Article)Bladder cancer complicating schistosomiasis is a major cause of cancer mortality in Egypt. It affects farmers who suffer from repeated and severe chronic schistosomal cystitis. The late presentation of this disease is ... -
Mineralogy, petrography and manufacturing of good quality Blackboard chalk
( Qatar University , 1996 , Article)Most of the Arabian countries produce bad quality and dusty blackboard chalk. Good quality and dustless blackboard chalk are usually imported from Europe, China, Taiwan and the United States of America. The essential raw ... -
Structural Elements And Formation Parameters For Some Lower Cretaceous Sequences In The Western Desert, Egypt
( Qatar University , 1987 , Article)The Lower Cretaceous sequences in the northern part of the Western Desert has been penetrated by many of drilled bore—holes adopted by different oil companies. It was encountered at depths ranging from 1200 to 3500 m. The ...
