Browsing Qatar University Science Journal - [From 1981 TO 2007] by Title
Now showing items 667-686 of 770
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Strong and Weak n-Homogeneous Spaces
( Qatar University , 2004 , Article)In this paper we introduce new types of n-homogeneity, we call them n-homogeneous of type 2 and type 3, denoted by nH2, nH3 respectively. We show that every 3H3-space is bihomogeneous space. Also, every finite nH3-space ... -
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 ... -
The structure of tetraketones in the solid state: the crystal structure of 1,6- Diphenylhexane-1,3,4,6-tetrone
( Qatar University , 1994 , Article)The crystal structure of l,6-diphenylhexane-l,3,4,6-tetrone was determined, CjgHi4O4, M 294.31 monoclinic, space group P2j/n (# 14), a 5.1192 (6) A, b 9.085 (9) A, c 15.366 (4) A, b 97.91 (4)°, p (calc) 1.362 g/cm3, Z 2, ... -
The Structures And Mode Of Formation Of Some Cyclodiphosphazane Derivatives With Urea And Thiourea
( Qatar University , 1986 , Article)The methods of preparation and possible reaction mechanisms for the formation of some geminal and nongeminal aminocyclodiphosph (v) azanes of the type (II - V) are discussed. These cyclodiphosphazanes obtained from the ... -
Studies for determining antimicrobial activity of solenostemma argel (del) hayne. 1-extraction with methanol/water in different proportions
( Qatar University , 1994 , Article)Aerial parts of Solenostemma argel plant were successively extracted with methanol/water in different proportions (4 fractions). The phytochemical and chromatographic screening as well as quantitative determination of the ... -
Studies for determining antimicrobial activity of solenostemma argel (del) hayne. 2-extraction with chloroform/methanol in different proportions
( Qatar University , 1994 , Article)Aerial parts of Solenostemma argel plant were successively extracted with chloroform/methanol in different proportions (4 fractions). The phytochemical and chromatographic screening as well as quantitative determination ... -
Studies in bidirectional movement in vicia faba l.
( Qatar University , 1984 , Article)Surgery was used to investigate bidirectional movement in a single vascular bundle of Vicia faba L. In one experiment it was found that radiocarbon had moved upwards and downwards via one isolated bundle when leaf one and ... -
Studies On Bottom Trawling And Demersal Fishes Of Qatar Waters, Arabian Gulf
( Qatar University , 1989 , Article)The bottom trawl fishery and their by-catch from Qatar waters were analysed on a systematic basis for species composition, length, weight and girth-among other things-during the year 1986-1987. The resuls proved a steady ... -
Studies On Catch Rates Of Bottom Trawlers In Qatar Waters, Arabian Gulf
( Qatar University , 1990 , Article)Data pertaining to catch, effort, time, space, landing, commercial value, by-catch and some environmental parameters covering the period from 1983 to 1988 were used in this regard. The results conformed that; the CPUE ... -
Studies on digenetic trematodes of some red sea fish 1. General survey
( Qatar University , 1983 , Article)812 Red Sea fish, belonging to 33 species, were examined for digenetic trematodes. All species of fish were infected with one or more genera of trematodes. Out of 812 fish, 394 (48.5%) were positive. The incidence of ... -
Studies on growth and chemical composition of tobacco varieties. IV - comparative effects of various combinations of fertilizers on economic potentialities of tobacco plants
( Qatar University , 1987 , Article)In two experiments, tobacco plants were treated with various combinations of ammonium nitrate (23% N) and compound C (3.5% N, 23% P and 16% K). At all levels used in experiment I, stem length and number of leaves were ... -
Studies On Plant Growth Regulators And Enzymes Production By Some Bacteria
( Qatar University , 1994 , Article)Twenty four bacterial strains of thallobacteria belonging to genus Streptomyces were tested for their potentialities to produce plant growth regulators and some hydrolases in shake cultures. Seven strains namely; Streptomyces ... -
Studies On Possible Factors In Saliva In The Etiology Of Oral Cancer
( Qatar University , 1994 , Article)The present study was performed on 195 individuals divided according to their oral hygiene into the following four groups; Group I: Control healthy individuals; Group II: Patients suffering of early to moderate periodontitis; ... -
Studies on Soil Cements : 2 — Physicochemical Properties of the Hardened Soil Cement Pastes.
( Qatar University , 1982 , Article)Various hardened soil-cement pastes were prepared from dry mixtures of montmorillonite clay and portland cement clinker by using different W/C ratios of 0.20, 40, 0.60 and 0.80 and cured in air for various ages. Compressive ... -
Studies on Soil Cements: 1 - Role of Hydrated Lime and Dolomitic Monohydrate in Montmorillonite Stabilization
( Qatar University , 1982 , Article)Montmorillonite clay was stabilized by either hydrated lime or the dolomitic monohydrate (Ca(OH)2. MgO) during suspension hydration at 25 and 60°C for 45 days. The distinct phases produced from the hydration of each ... -
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 ... -
Studies on some cowpea cultivars: II - suitability for aspergillus flavus growth and Aflatoxin production
( Qatar University , 1993 , Article)Sixteen mycotoxin-free seed cultivar samples of cowpea (Vigna unguiculata (L.) Walp.) were inoculated with spores* of Aspergillus flavus Link (IMI 89717) to determine varietal differences in terms of aflatoxin production. ... -
Studies On Some Fetal Rat Organs Following Maternal Hyperthermia
( Qatar University , 1993 , Article)The present investigation was carried out to determine the histological changes in brain, liver and kidneys of rat fetuses maternally heatstressed at early stage of pregnancy to either high "spiking" temperature of short ... -
Studies on the biology of eucalyptus micro theca f. Muell in the gezira, sudan i. The behaviour of the seed
( Qatar University , 1986 , Article)Eucalyptus microtheca has proved to be a success on the heavy clay soils of the Gezira. This tree species not only seeds regularly and prolifically during the summer, but also, though rarely, seeds during the winter. The ... -
Studies On The Decay Of 241Am
( Qatar University , 1989 , Article)The gamma-spectrum of '"Np following the <X -decay of "'Am has been studied using hyper pure Ge-detector and Ge-NaI(Tl) coincidence spectrometer. Some recently reported weak gamma transitions are confirmed, besides two ...