Search
Now showing items 1271-1280 of 1470
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 ...
Additions to the flora of Qatar
(
Qatar University
, 1997 , Article)
Collections and earlier studies on the plants of Qatar are limited and of recent origin — since the seventies. The latest of these in 1983 (El Amin) listed 300 species belonging to 202 genera in 56 families. At present, a ...
Dinoflagellate Cysts and Miospores from the Albian - Cenomanian Sequence of the Qarun 2 - 1 Borehole, Western Desert, Egypt
(
Qatar University
, 1993 , Article)
Rich distinctive dinoflagellate cyst assemblages together with significant numbers of miospores were recovered from seven cuttings samples in the Qarun 2 - 1 borehole between 2718 - 2854 m. This association represents a ? ...
Effect Of Adsorption Of Tetrabutylammonium Chloride In Polarography
(
Qatar University
, 1994 , Article)
The polarographic behaviour of chromate, iodate and zinc has been investigated in the presence of different concentrations of tetrabutylammonium chloride in 0.1 M Na2SO4 and 0.1 M H2SO4. The effect of organic compound on ...
Threshold Modelling Of Ship's Dynamics
(
Qatar University
, 1995 , Article)
In this paper we consider an application of a system called threshold system in the field of marine engineering. Properties of this system are discussed and the idea of the impulse response function of threshold system is ...
Blastema Volume And Nuclear Size In The Regenerating Hind Limbs In Larvae Of Xenopus Laevis And Bufo Regularis After Transection At The Ankle Level
(
Qatar University
, 1990 , Article)
After amputation at the ankle level of hind limbs in larval Xenopus laevis and Bufo regularis, an increase in the nuclear volume of blastema and stump tissue cells was observed. The cells in the distal region of blastema ...
Mineralogical And Geochemical Evaluation Of Upper Cretaceous Black Shales, Safaga District, Egypt.
(
Qatar University
, 1995 , Article)
Lithologic and compositional properties of black shale and pyrite from the Upper Cretaceous phosphorite/black shale deposits (Duwi Formation) of Eastern Desert of Egypt indicate similarity in mineralogy, geochemical ...
Studies on some cowpea cultivars: II - suitability for aspergillus flavus growth and Aflatoxin production
(
Qatar University
, 1993 , Article)
Sixteen mycotoxin-free seed cultivar samples of cowpea (Vigna unguiculata (L.) Walp.) were inoculated with spores* of Aspergillus flavus Link (IMI 89717) to determine varietal differences in terms of aflatoxin production. ...
The influence of certain physical stresses on pulal mortality of Culex pipiens complex L. II. Effect of exposure to oxygen and partial vacuum.
(
Qatar University
, 1993 , Article)
The results indicated that when pupae were exposed to oxygen atmosphere for different periods ranging from V2 - 48 hours, the pupal mortality increased with increasing the exposure periods. The mortality reached to about ...
Ecological Notes On The Floristic Composition And Endemic Species Of Saint Catherine Mountains, South Sinai, Egypt
(
Qatar University
, 1995 , Article)
The present study is aimed at (1) giving complete list of all plant speciec growing in Saint Catherine mountains, (2) studying the relationship between species number and the amount of precipitation at the time of study ...