Qatar University Science Journal - [From 1981 TO 2007]: Recent submissions
Now showing items 21-40 of 770
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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, ... -
Inhibition Effect Of Four Oil Dispersants On Primary Productivity In Qatar Water (Ararian Gulf)
( Qatar University , 1987 , Article)Four major oil dispersant mixtures in seawater wore used to depict their in—situ inhibition ratio to productivity rate of natural phytophanklon populations in Qatar water — Arabian Gulf — during the spring season of 1986. ... -
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 ... -
Window Analysis Optimization Of Gas Chromatographic Separation Using Different Polarity Packed Columns
( Qatar University , 1996 , Article)Window diagram theory has been described by Purnell and his research team in various publications. In this paper we apply this theory to optimize a separation of complex mixture containing propylene oxide, 1-hexene, ... -
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- ... -
Seismic reflection coefficient parameter-theoretical and Practical approach
( Qatar University , 1994 , Article)In this study, the effect of porosity and pore filler on the reflection coefficient parameter (R), are well deduced and some mathematical expressions were developed. This leads to the establishment of new expression of (R) ... -
Some Enzymatic Activities Of Fungi Isolated From Cotton Seeds And Cotton Seed Products
( Qatar University , 1984 , Article)Five hundred different cultures which belong to fifteen genera and forty-one species, isolated from cotton seeds and cotton seed products were studied for proteolytic, amylolytic and lipolytic activities. About 80% of the ... -
Botanical Exploration Of Sinai
( Qatar University , 1985 , Article)The history of the botanical exploration of Sinai has been reviewed. It has been divided into the following periods: I. Expeditions in the eighteenth century. II. Exploration from 1800 till the publication of "Florula ... -
Haemogregarines of geckos in egypt, together with a description of haemogregarina helmymohammedi n.sp.
( Qatar University , 1995 , Article)Three species of geckos collected from various localities in Egypt were examined for protozoan blood parasites. Haemogregarines were reported in all the three species of geckos. Problems of the generic and specific ... -
Night Distribution Of Certain Species Of Coleoptera As Indicated By Captures In A Light Trap At Quena
( Qatar University , 1984 , Article)The night distribution of nineteen species over a whole trapping period can be considered under the following headings: a. Early flyers b. Species with two peaks of activity. The effect of light of low intensity, temperature ... -
A histological study on the neuroendocrinal system of a coleopterous insect, cy3ister tripunctatus africanus cast.
( Qatar University , 1983 , Article)Four different types of neurosecretory cells were identified in the brain of the adult water beetle, Cybister tripunctatus africanus Cast. These cells were identified into A, B, C, & D types according to their morphological ... -
Comparative Histopathological Studies On The Effects Of Ionizing X-Ray Irradiation On Normal Liver And Hepatoma
( Qatar University , 1984 , Article)Normal mice exposed to X-rays showed distinct external symptoms and died mostly on the 13th or 14th day after irradiation. Pathological symptoms were more exaggerated in mice diseased with hepatoma and subjected to the ... -
Evaluation of Some Local Egyptian Plants as a Source of Chlorophyll Pigments
( Qatar University , 1994 , Article)Four plant materials viz. Spinacia oleracae Linn, (spinach), Beta vulgaris Limm (chard), Medicago sativa Linn, (alfalfa) and Petroselinum sativum Hoff. (parsely) were studied as local sources for the preparation of chlorophyll ... -
Treptodemus Latus and chauhnotrema spiniacetabulum (tirematoda: digenea); Hemirhamphidae, parasites of the fish, hemirhamphus marginatus from Qatari waters
( Qatar University , 2000 , Article)The fish Hemiramphus marginatus recently examined from Qatari waters was found to be infected with two species of degenetic trematodes: Treptodemus latus Manter, 1961 and Chauhanotrema spiniacetabulum Nahhas ans Sey, 1998. ... -
Toxicity of Cobalt and Nickel to Fusarium Solani Isolated From Saudi Arabian Soil
( Qatar University , 1994 , Article)Fusarium solani isolated from Saudi Arabian soil was able to grow on liquid media containing up to 300 ug/ml cobalt or nickel. F. solani was tolerant to cobalt than nickel. The results provide evidence of the accumulation ... -
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 ... -
Stereochemistry of some high coordination compounds of dioxouranium(VI) With thiosemicarbazones
( Qatar University , 1994 , Article)The UO2 ion is peculiar in its coordination behaviour, because of its inherent capacity of forming compounds with higher coordination number. In the present work we describe the synthesis of a series of eight, nine and ten ... -
Reproductive ecology of the common rock chiton Acanthopleura gemmata (mollusca: polyplacophora) in the Northwestern coast of the red sea
( Qatar University , 1996 , Article)The reproductive cycle of the chiton, Acanthopleura gemmata was studied by observing the gonad indices at two localities in the North-western coast of the Red Sea, from January 1988 to December, 1989. The interrelationships ... -
Ecophysiological Characteristics, Distribution, and Nutritional Value of Desert Range Plants in Qatar
( Qatar University , 1993 , Article)Despite the scarcity of water, desert ranges of Qatar can support a characteristic diversity of species and an all-year-round supply of feed. A correlation between carbon dioxide fixation mechanism, distribution of species, ... -
Red cell superoxide dismutase in patients with different liver diseases
( Qatar University , 1995 , Article)Supcroxidc dismutase (SODs, supcroxidc oxidoreductasc, E.C. 1.15.1.1.) activity has been estimated in red blood cells from patients suffering from liver cirrhosis and hcpatoccllular carcinoma. Erythrocytcs supcroxide ...
