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السجلات المعروضة 21 -- 28 من 28
Studies on Soil Cements : 2 — Physicochemical Properties of the Hardened Soil Cement Pastes.
(
Qatar University
, 1982 , Article)
Various hardened soil-cement pastes were prepared from dry mixtures of montmorillonite clay and portland cement clinker by using different W/C ratios of 0.20, 40, 0.60 and 0.80 and cured in air for various ages. Compressive ...
Synthesis and reactivity of 2-chloro-4-phenyl-6-p-tolyl-nicotinonitrile Towards some nucleophiles
(
Qatar University
, 1986 , Article)
The synthesis and reaction of 2-Chloro-4-phenyl-6-p-tolyl- nicotinonitrile (I) with hydrazine hydrate, sodium azide and urea to give the corresponding hydrazino tetrazolopyridine and urea derivatives respectively, are ...
Synthesis And Biological Activity Of Some New 4-(Aminoacyl) Aminopyridines And 2-(Aminoacyl) Aminopyrimidine Derivatives
(
Qatar University
, 1983 , Article)
The synthesis of 4-(N-Tos and N-Pht-aminoacyI) aminopyridines (III - XIV) and 2-(N-Pht-aminoacyl)-aminopyriniidines (XV-XXIV) has been achieved employing the acid chloride and carbodiimide methods. Hydrazinolysis of ...
The Complexation of Lanthanides by Azo-B-Diketones Stability Constants
(
Qatar University
, 1982 , Article)
The stability constants of the complexes between the trivalent lanthanide series of cations and series of azo-B-diketone ligands are reported. The measurements were conducted at 30°C and zero ionic strength (free KN03), ...
Petrographic Studies of the Alamein Dolomite (Lower Cretaceous) in El-Razzak Oil Field, Western Desert, Egypt
(
Qatar University
, 1982 , Article)
The origin and environment of deposition of the Alamein Dolomite in the El-Razzak Oil Field have been investigated by means of petrographic, chemical and X-ray analysis.
The studied rocks are composed of dolomite with ...
Study of Magnetic Properties and Lattice Dynamics of the Cdx Co1-x Ferrite System by MossbauerEffect
(
Qatar University
, 1981 , Article)
The magnetic properties and lattice dynamics of the spinel ferrite system Cdx Coi-x Fe^ 04 (x = 0.0, 0.1, . . . , and 1.) were studied in the temperature range between 78 to 800°K. The results showed that the samples with ...
Constituents of catha edulis (alkaloids, triterpenoids and related substances and saponins)
(
Qatar University
, 1989 , Article)
The study of the alkaloids of khat samples from Egypt and Yemen revealed qualitative and quantitative differences. Cathine and the dimer of cathinone occured in both samples, while norephedine was detected only in Yemen ...
Constituents Of Cymbopogon Species
(
Qatar University
, 1986 , Article)
A comprehensive review of the Cymbopogon species including the essential oils and their constituents is given. An account of the other components viz. non volatile terpenoids and phenolic compounds is also given. The ...