Browsing Qatar University Science Journal - [From 1981 TO 2007] by Title
Now showing items 215-234 of 770
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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 ... -
Effects of electric and magnetic fields on the energy levels of a hydrogenic impurity in GaAs/Gal-xAl x As heterjunction
( Qatar University , 1997 , Article)Variational method within the effective — mass approximation is used to calculate the shallow impurities states in GaAs / Gai_xAl^As heteroj unctions. Modified Fang-Howard wavefunction is used as the trial wavefunction. ... -
Effects of gamma radiation on reproduction, Mating competitiveness and sperm activity of Callosobruchus chinensis (l.)
( Qatar University , 1994 , Article)The effects of gamma irradiation at different doses on the adult stage of Callosobruchus chinensis L. were studied. Adult fecundity and fertility decreased by increasing the radiation dose and effects of the treatment were ... -
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 ... -
Effects of gamma radiation on the activity of the, mosquito culex pipiens L. : I. Effects on the attraction of the mosquito to light, colours and host
( Qatar University , 1988 , Article)The present work was carried out to investigate the effects of gamma radiation at three doses: 40, 80 and 120 Gray. On the response of the adult mosquito Culex pipieas complex when irradiated in the larval, pupal or adult ... -
Effects of gamma radiation on the Elemental composition of the flour moth Ephestia kuhniella z
( Qatar University , 1994 , Article)The effect of gamma radiation on the elemental composition of larvae, pupae and adults stages of the flour moth Ephestia kuhniella after irradiation of eggs to the sterilizing dose was studied. The elemental composition ... -
Effects Of Gamma Radiation On The Mating Activity Of The Mediterranean Fruit Fly. Ceratitis Capitata Weid
( Qatar University , 1987 , Article)Full grown pupae of the Mediterranean fruit fly, Ceratitis capitata Weid were exposed to three doses of gamma radiation, 50 70 and 90 gray. The effects of irradiation on the fly mating activity were studied. There was no ... -
Effects Of Gamma Radiation On The Motility And Attraction Of The Mediterranean Fruit Fly Ceratitis Capitata Wied, To Light, Colours And Odour
( Qatar University , 1988 , Article)Full grown pupae of the Mediterranean fruit fly, Ceratitis capitata were irradiated at three gamma dosages (50, 70 and 90 gray). The different effects on the motility and attraction to light colours and odour of the produced ... -
Effects Of Gamma Radiation On The Sexual Attraction Of The Mediterranean Fruit Fly. Ceratitis Capitata Wied
( Qatar University , 1987 , Article)The Mediterranean fruit (ly, Ceratitis capitata Weid, was gamma irradiated as full grown pupae with 50, 70 and 90 gray. The produced adults were examined for their attractiveness to the non irradiated (normal) other sex. ... -
Effects Of Overfishing And Abandoning Bottom Trawling On Qatar's Fisheries
( Qatar University , 1996 , Article)The present study was conducted to overview the effects of abandoning bottom trawling and increasing fishing effort on the structure and dynamics of Qatar's fisheries during 1985-1994, using the fishery statistics data, ... -
The effects of sea water immersion on the mechanical properties of low density polythylene
( Qatar University , 1997 , Article)The effects of immersion of low-density polyethylene (LDPE) m seawater for times of up to one year were studied using mechanical and ultrasonic techniques. The studies were carried out in the laboratories of the Faculties ... -
Effects of the electric field and gamma Radiation on the optical properties of Modified low density polyethylene
( Qatar University , 1997 , Article)The effect of electric field and gamma radiation on the optical properties of low density polyethylene LDPE grade CD 0230 have been studied. The samples were irradiated at gamma doses of 0-100 Mrad and varying electric ... -
Effects of the expected sea level rise on avicennia marina L: a case study in Qatar
( Qatar University , 1995 , Article)A simulation of the expected sea levels rise was carried out by imposing a state of protracted flooding on seedlings of the mangrove species Avicennia marina L. under natural conditions. The imposed flooding resulted in ... -
Efficiency Of Ground Water Resources In Northeast Sinai Peninsula, Egypt
( Qatar University , 1993 , Article)The present study deals with actual quantitative and qualitative evaluation of the groundwater resources in El Sheikh Zuwayid-Rafah area, the northeast coast of Sinai Peninsula. The quantitative analysis is achieved by ... -
The electrical and optical properties of poly (4-ethylidene-l, 3-cyclopentylene vinylene)
( Qatar University , 1989 , Article)The intrinsic viscosity, electrical conductivity and IR absorbance were measured for the sample of poly (4—ethylidene—1, 3—cyclopentylene vinylene). The sample is strongly oxidized in air. Under vacuum the activation energy ... -
Electrical Properties Of The Lower Eocene Rocks In Qatar
( Qatar University , 1987 , Article)Thirteen limestone samples representing the Rus Formation (Lower Eocene) are selected' from four locations in Qatar Peninsula. These samples are subjected to electrical resistivity, porosity, shaliness factor and water ... -
Electrochemical behaviour of some pyrimidine derivatives: polarographic reduction of 1, 3-dimethyl-2, 4, 6(1h, 3h, 5h) pyrimidinetrione and its substituted 5-phenylazo
( Qatar University , 1994 , Article)The polarographic behaviour and spectrophotometric pKa of 1,3-dimethyl barbituric acid and 5-phenylazo substituted products were investigated in buffer solution of pH ~ 2-11. The results revealed an azo form of the substituted ... -
Electron microscopic and autoradiographic analysis of the distribution of the vagus nerve in the ferret stomach
( Qatar University , 1999 , Article)In this study, tritiated leucine was injected into the vagal dorsal motor nucleus after acute and chronic partial vagotomy. The method of sampling of the stomach, application of % 2 test and the analysis of the electron ... -
Electrophoretic patterns of proteins and enzymes in paramphistomum (p.) Microbothrium and carmyerius gregarius
( Qatar University , 1990 , Article)The electrophoretic patterns of total soluble proteins, esterases, Glutamic-oxaloacetate transaminase (GOT) and malate dehydrogenase (MDH) are determined in two paramphistomes, infecting cows and buffaloes, namely ... -
Elliptic surfaces over a genus 1 curve with exactly the pair (I8, IV) of singular fibers
( Qatar University , 2000 , Article)In this paper we classify all minimal elliptic surfaces (TI : E —> C) over a genus 1 curve C, with a section and exactly the pair (Is, IV) of singular fibers.