Qatar University Science Journal - [From 1981 TO 2007]: Recent submissions
Now showing items 421-440 of 770
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Multielement Analysis Of Suspended Particulates In Doha (Qatar) Air Before And During The Gulf War
( Qatar University , 1994 , Article)Efforts have been made to study the effect on Qatar atmosphere from the burning of Kuwait oil fields during the Gulf war. Analysis of suspended air particulates was done by X-ray fluorescence technique. Eight elements were ... -
A Problem In Thermoelasticity With Two Relaxation Times For An Infinite Thermoelastic Layer
( Qatar University , 1995 , Article)The problem of a ihcrmoclastic layer of finite thickness and infinite extent is considered within the context of the theory of thcrmoclasticity with two relaxation times. The upper surface of the layer is taken as stress ... -
The blood cells of a sea urchin from abou-kir coast Alexandria, Egypt.
( Qatar University , 1993 , Article)The blood cells of a common sea urchin, collected from Abou-Kir region, were investigated using light and electron microscopy. Their distribution, properties, characteristics and histogenesis were determined. On the basis ... -
Biostratigraphy Of The Upper Cretaceous-Lower Tertiary Rocks Of South Jordan Based On Planktonic Foraminifera
( Qatar University , 1983 , Article)This paper deals with the Biostratigraphy of the Upper Cretaceous - Lower Tertiary rocks of Dm Rijam area. South Jordan. The study is based on 82 identified planktonic foraminiferal species. Ten foraminiferal biozones are ... -
Collineations Of Polar Spaces
( Qatar University , 1990 , Article)In this paper we consider general embeddable polar spaces with Witt index at least three. If π : S( ξ) —> S( ξ’) be a thick collineation between polar spaces with i( ξ) =i( ξ’) ≥3. Then there exists a place Ø: k—> k' U ... -
The Neurosecretory Cells and Neurosecretions in the Developmental Stages of the Cotton Leafworm -Spodoptera Littoralis (B)
( Qatar University , 1981 , Article)In 1955 Nayar described two types of neurosecretory cells in lphita limbata (A- and B-types) [1]. Later, Johannson [2] classified these cells into four categories: A, B, C and D, which he regarded as motor neurones of ... -
Volatile Components of the Phaeophyceae Hormophysa cuneiformis Growing Along Qatar Coasts
( Qatar University , 2007 , Article)The present work deals with the study on volatile compounds from the brown alga Hormophysa cuneiformis collected from the Northwest coast of Qatar on May 2002. Two extraction methods have been used: conventional hydrodistillation ... -
The Antibiotic Activity Of Some Aquatic Plants And Algal Extracts From Jordan
( Qatar University , 1991 , Article)The antimicrobial activity of the extracts of three fresh water green algae, four marine green algae, two brown marine algae and five red marine algae from the Jordanian part of the Aqaba Gulf, together with four aquatic ... -
Marine Algae As Bioindicators Of Pollution Levels In The Arabian Gulf
( 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 ... -
A Problem In Magneto-Thermoelasticity For A Hollow Circular Cylinder With Thermal Relaxation
( Qatar University , 1997 , Article)The problem of an infinitely long annular cylinder whose inner surface is thermally insulated and whose outer surface is kept at a constant temperature is considered in the presence of an axial uniform magnetic field. The ... -
Studies On The Effect Of Cadmium Chloride On The Gonads Of The Developing Chick Embryos
( Qatar University , 1987 , Article)Cadmium chloride was injected in doses of 5, 10, 15 and 20 /xg/egg into the yolk sac of 4—day—old chick embryos. Mortality due to cadmium intaxication increased with dose increase. The mortality rate of chick embryos ... -
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 ... -
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 ... -
Separation of Two Forms of Extracellular p-glucosidase From a Thermotolerant Aspergillus niveus
( Qatar University , 2003 , Article)Two forms of P-glucosidase ((3-D-glucoside glucohydrolase, EC 3.2.1.21) from the culture filtrate of Aspergillus niveus were separated and partially purified by gel chromatography on Sephadex G-100 column. The two forms ... -
Pelagic Fish Resources And Their Fishery Around Qatar
( Qatar University , 1983 , Article)The existing pelagic fishery around Qatar is relatively smaller than the demersal fishery. Inshore and offshore gillnetting trolling and even bottom trawling, contribute to the production of pelagic fish species. About 30 ... -
Effect Of Temperature On Hyalomma (Hyalomma) Impeltatum Schulze And Schlottke (Ixodoidea: Ixodidae)
( Qatar University , 1988 , Article)The effect of 21, 25, 29 and 34°C on developmental period duration, weight of different stages in the life cycle and conversion efficiency in Hyalomma (H.) impeltatum Schuize and Schlottke was investigated at 75% relative ... -
Balanced Cross-Section Across The Southern Utah Overthrust Belt (Otb)
( Qatar University , 1995 , Article)Balanced cross-sections are offering the chance of better understanding of areas of complex geological structures that are insufficiently understood. Detailed field study and structural analysis by employing geometric ... -
Effects Of Chemical Pesticides On The Gravid Females And Stadia Of The Woodlouse, Porcellio Scaber (Latreille) (Isopoda, Oniscidea)
( Qatar University , 1991 , Article)Studies were made on the mortality rates of the gravid females, and on the survival and growth rates of the stadia of the woodlouse Porcellio scaber (Latreille) exposed for a period of 21 days to sub-lethal concentrations ... -
Appraisal into Phytochemistry and Taxonomy of an Old Plant Collection from The Middle East
( Qatar University , 1997 , Article)The English traveller Richard Pococke (1704 -1765) visited the Middle East during the period 1737-1740 and collected medicinal plants from localities in Egypt and Arabia. This collection gave a description of the Middle ... -
Attenuation Of Bacillus Cereus Spores By Different Factors
( Qatar University , 1993 , Article)The spore suspension of Bacillus cereus K] ]s was exposed to different concentrations of NaCl. NaNo3 and NaNC>2 as curing agents. The spores were able to tolerate 10% NaCl. Up to 4%, NaNC>3 had little or minor effects on ...
