Qatar University Science Journal - [From 1981 TO 2007]: Recent submissions
Now showing items 61-80 of 770
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Analysis Of Al Diffusion In Molten Germanium Induced By Pulsed Nd: Yag Laser Using Sims Technique
( Qatar University , 1996 , Article)In this work the volume diffusion coefficients and profile distribution of Al impurities in molten germanium have been measured using secondary-iron mass spectroscopy (SIMS) technique. Diffusion is achieved with aid of ... -
Population biology of sparid fishes in qatari waters. 1 - reproductive cycle and fecundity of longspine seabream, Argyrops spinifer (Forskal)
( Qatar University , 1993 , Article)The reproductive cycle, gonads maturation, gonado-somatic indices (GSI) and fecundity of longspine seabream Argyrops spinifer from the Arabian Gulf waters off Qatar were investigated. Bi-weekly samples representing all age ... -
On The Earthworm Fauna And Distribution In The State Of Qatar
( Qatar University , 1986 , Article)This paper is a preliminary account of the earthworms collected in February and March, 1986, from 10 localities in Qatar. Five species, Amynthas corticis (Family Megascolecidae), Dichogaster bolaui (Family Octochaetidae), ... -
Constituents Of Green Beans Phaseolus Vulgaris (Lipids And Flavonoids)
( Qatar University , 1992 , Article)Chemical study of the lipid fraction resulted in the isolation and identification of a hydrocarbon fraction (n-Czg -0-033); an aliphatic alcohol fraction (C^, Czp, €30) and a sterol fraction (stigmasterol and sitosterol). ... -
Reproducing Formula and Algorithm of a Familv of Biorthonormal Wavelets
( Qatar University , 2005 , Article)In this paper we present a family of biorthonormal wavelets generated by a MRA orthonormal wavelet, which possesses two arbitrary parameters. Then we discuss new expressions of reproducing kernel as well as the corresponding ... -
Planting Date Effect On Growth Characters And Yield Of Sorghum Under A Dry Farming-System In An Arabian Gulf Environment
( Qatar University , 1996 , Article)Irrigated crop production in Qatar is a risky enterprise due to extreme weather conditions. Temperature is sufficiently warm to allow planting of grain sorghum [Sorghum bicolor (L.) Moench] from Aug through to Oct. Crops ... -
Screening Of Some Fungi For Uricolytic Activity
( Qatar University , 1996 , Article)Twenty nine species of fungi have been tested for their uricase activity. Only twenty two species of them have the ability to produce uricases. Most of the uncapable fungi to produce uricases belong to Basidiomycotina. ... -
Effect of Rhizohnim melilotti and VA-mycorrhizac on Forage Yield and Quality of Two Alfalfa Cultivars
( Qatar University , 2003 , Article)An experiment was conducted at the Demonstration Farm of the faculty of Agriculture, University of Khartoum at Shambat during the period December 1997 to June, 1999, to investigate the effect of Rhizobium meliloti and ... -
Ruthenium(II), Ruthenium(III) And Osmium(III) Complexes With Rn-Neutral Donor Ligands, And Their Catalytic Oxidative Properties
( Qatar University , 1994 , Article)A number of new complexes [RunCl2 (PPh3)2L], [RumX3 (AsPh3)L] and [OsnICl3(PPh3)L'] [L= o-anthranilonitrile(anth), o-phenylenediamine(phdm), l,10-phenanthroline(phen), 2,2'-bipyridine(bipy); L' = Phen, bipy; X = Cl, Br] ... -
Plant growth, metabolism and adaptation in relation to stress conditions. Vii. Respiration, nitrogen and proline contents in french bean and maize plants as influenced by salinity
( Qatar University , 1989 , Article)Carbon dioxide production by seedlings, whole plants and leaves of French bean and of maize showed progressively greater increases with increasing concentrations of Na2S04 added to the basal medium. Also, in response to ... -
Petrophysical Studies on Samples from Eocene Exposures West Cairo-Egypt
( Qatar University , 1981 , Article)The present work deals with petrophysical and petrochemical studies on 58 limestone samples of Eocene age in two localities west of Cairo (Sakkara and Giza Pyramids Plateau). The determined petrophysical properties are: ... -
Synthesis and biological testing of 2,4-disubstituted thiazole derivatives as Potential antitumor antibiotics
( Qatar University , 1994 , Article)A series of thiazole derivatives bearing amino, acetamido or thioureido synthons at position 2- and thiosemicarbazone or 1,2,4-triazolethione moieties at position 4- have been synthesized and evaluated for their antimicrobial ... -
Effect Of Oral Administration Of Alcohol On The Developing Rat Embryos
( Qatar University , 1988 , Article)Pregnant rats were forced to ingest 0.015 ml of 25% ethanol/gm body weight daily starting from day 7 (D7-group) or day 9 (D9-group) until day 15 of gestation. The number of surviving embryos significantly decreased and ... -
Decomposition of a Special Type of Machines
( Qatar University , 1994 , Article)In this paper, the concept of a finite n-state cyclic machine An is defined. These machines are then completely characterized using the prime factorization of n. Specifically, it is proved that any finite-state cyclic machine -
Effect of chemical grafting on the surface structure of porous bentonite as a support in gas chromatography
( Qatar University , 1994 , Article)The effect of thermal and chemical treatments on the variation of specific surface area of porous bentonite as a support was studied. The surface area of bare bentonite thermally treated at 950°C and then washed with ... -
Viscous Behavior of Dilute CMC Salt Solution Before and After Photodegradation
( Qatar University , 2006 , Article)Photodegradation curve of carboxymethylcellulose (CMC) in aqueous solution has been reported. Densities and solution viscosities of very dilute CMC salt solution before and after UV-irradiation have been measured. ... -
Factors Governing Mosquito Susceptibility To Bacillus Sphaericus Strains
( Qatar University , 1992 , Article)Three lyophilized strains of Bacillus sphaericus (1593-4, 2297 and SSII) were tested against four different mosquito species. Culex pipiens larvae demonstrated the highest level of susceptibility towards the 3 B. sphaericus ... -
Mineralogy and Chemistry of Desert Roses, Ayn Dar Area, Abqaiq, Eastern Province, Saudi Arabia
( Qatar University , 2002 , Article)Desert roses are crystals which usually take the form of rose petal. They have definite crystal shapes, and enclose sand grains. The desert roses were scattered along an area of about 500m2 in the Ayn Dar area, near Abqaiq, ... -
Pullulan production from sugar beat molasses
( 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 ... -
Thermal Acclimation In The Resting Metabolism Of The Nocturnal Gecko, Hemidactylus Flaviviridis
( Qatar University , 1996 , Article)Hemidactylus flaviviridis was acclimated to two temperature regimes (20 and 30°C). The resting metabolic rates (ml g1 h"1) were determined at 20, 25,30 and 35°C, using constant pressure manometric respirometers. The 20°C- ...
