Qatar University Science Journal - [From 1981 TO 2007]: Recent submissions
Now showing items 341-360 of 770
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New Records Of Some Mammals From Qatar: Insectivora, Lagomorpha And Rodentia
( Qatar University , 1984 , Article)The present report deals with six native mammalian species to be recorded for the first time from Qatar. They belong to the following orders: Insectivora, Lagomorpha and Rodentia. None of these species is endemic to Qatar. -
Adsorptive Properties of a Desert Salsola Vermiculate Species from Synthetic Aqueous Solutions
( Qatar University , 2006 , Article)Pollution is becoming a major environmental problem and the current trend is to use available biomass to remove toxic substances from aqueous solutions. The preliminatry adsorption results on a natural Salsola Vermiculata ... -
Middle-Upper Devonian And Lower Carboniferous Miospore Assemblages From Western Desert Of Egypt
( Qatar University , 1985 , Article)Important morphological features of some spore assemblages from Middle-Upper Devonian and Lower Carboniferous of Western Desert of Egypt are described. Comparing the present assemblages with those obtained from other ... -
Water Quality Of The Area West Of Karak City, Jordan
( Qatar University , 1986 , Article)The water quality of some wells, wadis and springs in the area west of Karak City has been evaluated for irrigation and domestic uses, by the application ofWilcox (1955) and Doneen (1961) methods, as well as the standards ... -
Gravitational Instability of a Radiating Gas Cloud with Variable streams
( Qatar University , 2001 , Article)The self-gravitating instability of a radiating gas cloud possessing variable streams is investigated. The self-gravitating force is destabilizing according to restrictions, the radiation has a strong stabilizing influence ... -
Spectroscopic Studies On Some Methylphosphonothioic Diamides And Related Compounds
( Qatar University , 1987 , Article)A series of methylphosphonothioic diamides MrP (S) (NHR)., ( R = Mr, pr' and Bu') and some related compounds viz, PhP(S)(NHBu)a ,P1^P(S) ( NHCHJ'h ) arc preparpd and their infrared, n.m.r. and mass spectra arc- recorded. ... -
Neutron Diffraction And Mossbauer Effect Study On A Mixed Rare Earth Garnet
( Qatar University , 1983 , Article)A powder sample of Y^YbFesO,; was prepared using the ceramic technique. X-ray diffraction pattern showed a single phase of the garnet type structure with a lattice constant 12.323 A". Specific heat for this composition was ... -
Comparative studies of the oil from silybum marianum cultivated in Egypt using glc
( Qatar University , 1994 , Article)Quantitative comparative study of the oil fraction constituents in the fruits of Silybum marianum successfully cultivated in new reclaimed land with those of the two wild types viz., purple flower and white flower bearing ... -
Halophytes and Soil Salinity in Qatar
( Qatar University , 2002 , Article)Saline soils cover approximately 6% of the land in Qatar. Halophytes are common along the coastal areas and inland salt flats and wetlands, where saline water is available in their natural habitats permanently or periodically. ... -
Calcareous Nannoplankton From The Turonian-Maastrichtian Sequence East Of El Qusaima, Ne Sinai, Egypt
( Qatar University , 1992 , Article)On terms of calcareous nannoplankton, the Turonian-Maastrichtian sequence in the studied area is subdivided into a number of nannoplankton zones. The recorded biozones represent the Turonian, Coniacian, Campanian and ... -
Effect of level of relative humidity on fungi and germination capacity of paddy (oryza sativa l.) Grains in egypt
( Qatar University , 1993 , Article)The changes in the composition of paddy grain-borne fungi in the germination capacity, and in the moisture content of paddy grains at various levels of relative humidity (r.h.) (~ 0-100%) stored at 20°C for 1, 2, 3 and 4 ... -
A rational logarithmic model for unconstrained non-linear optimization
( Qatar University , 1997 , Article)A new non-quadratic model is proposed for solving unconstrained optimisation problems which modifies and develops the classical conjugate gradient methods. The technique has the same properties as the classical conjugate ... -
Mitotic Disturbances Induced By The Drug "Novalgin" In Allium Cepa Root Tips
( Qatar University , 1984 , Article)Growing root tips of Allium cepa are treated with seven concentrations of Novalgin ranging from 2.81 x 10 4 M to 1.5 x 10 4 M for 4, 8, 24,48 and 72 hours. The frequency of mitotic phases in the treated roots varies ... -
Capabilities/limitations of landsat-tm data for bathymetric analysis of shallow marine environment: A case study
( Qatar University , 1999 , Article)The intensity of the light received by Landsat satellite sensors is inversely proportional to the path length though the sea water column. Since the light passes down to the sea floor and back again, the intensity should ... -
HPLC and MS analyses of lutein-esters from tagetes patula L.
( Qatar University , 1996 , Article)Investigation of the xanthophyll esters of Tagetes patula L. flowers resulted in the isolation and identification of lutein, lutein dimyristate, lutein myristate palmitate, lutein dipalmitate and lutein palmitate stearate. ... -
Mercury Pollution In Abu Kir Bay East Of Alexandria, Egypt
( Qatar University , 1992 , Article)Abu Kir Bay, east of Alexandria, is subjected to substantial pollution from two direct point sources which are Tabia Pumping Station (TPS) and Lake Edku Outlet (LEO). Mercury was speciated into dissolved reactive, dissolved ... -
Ecophysiology Of Desert Animals
( Qatar University , 1995 , Article)The principal environmental problems that confront both plants and animals in the desert are water shortage and flooding, thermal extremes, and the absence of cover. Adaptational responses to these include cryptobiosis, ... -
Effects of gamma radiation on the activity of the mosquito culex pipiens L. II. Effects on the sexual vitality of the mosquito
( Qatar University , 1988 , Article)The effects of 3 gamma doses on the sex vitality of the mosquito Culex pipiens L. were studied after irradiation of the larvae, pupae or newly emerged adults. No significant effect on the sex attraction was obseived when ... -
Spectroscopy in Corrosion Studies of Copper
( Qatar University , 1994 , Article)Spectrophotometric measurements were used to study corrosion of copper in aqueous solutions containing the four following depolarizers: K2Cr2O-j, K2S2O8, Fe(NH4)(SC>4)2 and CCI3COOH. A silica cell was used for the corrosion ... -
Methylated Flavonoids From Artemisia Monosperma
( Qatar University , 1989 , Article)Investigation of the flavonoid constituents of Artemisia monosperma resulted in the isolation and identification of four methylated flavonoids: quercetin 3,3',4'-trimethylether, diosmetin (luteolin 4'-methylether), ...
