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Now showing items 211-220 of 451
Diagonalizable Indefinite Integral Quadratic Forms
(
Qatar University
, 1991 , Article)
This paper deals with some special cases on Hasse's principle about the diagonalization of Z-lattices L of indefinite regular guadratic forms over Q. It is asserted that for some specific values of a certain set D of ...
Late Maastrichtian And Paleocene Calcareous Nannofossils From Ain Dabadib Section, Nw Kharga Oasis, Egypt
(
Qatar University
, 1991 , Article)
On terms of calcareous nannofossils, the late Maastrichtian and Paleocene sediments were subdivided into several biozones. The Cretaceous-Tertiary boundary is marked by a hiatus concerning the latest Maastrichtian and the ...
Thermometric Study of Inhibition of Aluminium Corrosion in Hydrochloric Acid Solution
(
Qatar University
, 1997 , Article)
The use of 6- amino - 4- (4-phenyl)-l,4- dihydro -3- methylpyrano [2,3- c] pyrazole -5- carbonitrile and some related compounds as corrosion inhibitors for aluminium in 2 M HCl solution was studied by the thermometric ...
Constituents of plants growing in Qatar xxiv phytochemical investigation of salvia aegyptiaca L.
(
Qatar University
, 1994 , Article)
The study of the flavonoids revealed the isolation and identification of luteolin, luteolin 7-O- glucoside, apigenin and apigenin 7-0 glucoside; their identity was proved by m.p., TLC, UV, IR and MS. Moreover, a coumarin ...
A Preliminary Check-List Of Benthic Mollusca On The Qatari Coasts, Arabian Gulf
(
Qatar University
, 1994 , Article)
In this paper, an annotated checklist of the benthic marine Mollusca collected from Qatari coasts, Arabian Gulf, is presented. Localities and habitats are given for the common families of the recorded groups. Gastropoda ...
Circulation And Water Masses And Their Implication On Pollutant Transport During Summer In Abuquir Bay (Egypt)
(
Qatar University
, 1991 , Article)
Abuquir Bay is a shallow area with a mean depth of about 10 meters, and it is affected by significant sources of industrial and agricultural pollutants. Water masses, the distribution of dissolved oxygen and total suspended ...
Plant phenology and its relation to the cool semi-arid condition of Sana'a
(
Qatar University
, 1997 , Article)
In the cool semi-arid highland areas of Sana'a a plant phenological study of forty two species revealed that there was one major
outburst of plant emergence corresponding with the first period of the heavy rainfall which ...
Plant Population Density Effects On Yield Of Sorghum Grown In A Dry-Land Farming System
(
Qatar University
, 1996 , Article)
Plant population studies in arid regions are very sparse and not well documented. A prerequisite in growing a successful sorghum (Sorghum bicolor [L.] Moench) crop is to obtain an adequate plant population. The response ...
Conductance Measurements in Corrosion Studies of Aluminium
(
Qatar University
, 1994 , Article)
A new method is suggested for studying the rates of dissolution of oxide film on aluminium and its alloys. The method is based on measuring the conductance between two aluminium (or its alloys) electrodes immersed in 3.0 ...
The effect of two substituents on different Organoselenides and tellurides to form new charge - transfer complexes
(
Qatar University
, 1999 , Article)
Different organotellurides and selenides were prepared as electron donors and reacted with p-Benzoquinone (p-BQ) and m-Dinitrobenzene (m-DNB) as electron acceptors.
The resulted molecules were considered as new charge ...