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Now showing items 21-30 of 87
Phytochemical investigation of thymus decassatus l. 1. Flavonoids and volatile oil
(
Qatar University
, 1993 , Article)
Investigation of the flavonoidal constituents of Thymus decassatus, L. resulted in the isolation and identification of thymonin, 5,6,4'-trihydroxy-7,3'-dimethoxyl flavone, and apigenin. Investigation of the volatile oil ...
Window Analysis Optimization Of Gas Chromatographic Separation Using Different Polarity Packed Columns
(
Qatar University
, 1996 , Article)
Window diagram theory has been described by Purnell and his research team in various publications. In this paper we apply this theory to optimize a separation of complex mixture containing propylene oxide, 1-hexene, ...
Evaluation of Some Local Egyptian Plants as a Source of Chlorophyll Pigments
(
Qatar University
, 1994 , Article)
Four plant materials viz. Spinacia oleracae Linn, (spinach), Beta vulgaris Limm (chard), Medicago sativa Linn, (alfalfa) and Petroselinum sativum Hoff. (parsely) were studied as local sources for the preparation of chlorophyll ...
Influence Of Surface Finish Parameters On Corrosion Of Zinc
(
Qatar University
, 1989 , Article)
The effect of surface parameters on corrosion behaviour of pure zinc in sodium sulphate solution was investigated. Surface parameters were determined using a Talysurf surface analyzer, and corrosion testing was performed ...
Oxidative Addition Reactions of Sn(II) And Pb(II) with Some Hydrazide And Hydrazone
(
Qatar University
, 2000 , Article)
Bivalent tin compounds can be easily transformed to tetravalent compounds by oxidizing agents. The use of ortho-quinones for oxidation of transition metals has been the subject of many publications, but few analogous studies ...
Pyrrolizidine alkaloids from alkanna orientalis (L.) Boiss
(
Qatar University
, 1992 , Article)
Three pyrrolizidine alkaloids; 7-angelyl retronecine (I), 9-angelyl retronescine (II), and dihydroxytriangularine (III) were isolated by DCCC and VLC from Alkanna orientalis growing in Egypt. Their structures were elucidated ...
Inhibition of Aluminium Corrosion in Hydrochloric Acid
(
Qatar University
, 1993 , Article)
The inhibitive effect of oximes, P-diketones and hydrazides, on the corrosion of aluminium in 2M HC1 has been investigated galvanostatically. The results suggest that, in presence of inhibitors, the anode is preferentially ...
Mechanism Of The Inhibition Afforded By Some Hydrazone Oxime Derivatives Towards Aluminium In 2m Naoh Solution
(
Qatar University
, 1991 , Article)
The effect of some hydrazone oxime derivatives on the corrosion of aluminium in 2M NaOH solution was studied by polarization and weight-loss techniques. Polarization data indicated that all inhibitors tested were of a mixed ...
Ecological and phytochemical studies on the "miswak", salvadora persica l.
(
Qatar University
, 1984 , Article)
The "Miswak", which is produced from the stolons and branches of Salvadora persica is used as a substitute for ordinary tooth brushes. The use of "Miswak" has been recommended by Islam. It is endowed by several characteristics ...
Biochemical Characterization Of Human Schistosomes And Their Molluscan Hosts By Electrophoretic Techniques
(
Qatar University
, 1994 , Article)
The recent application of biochemical techniques in taxonomy markedly improved the specific identification and strain characterization of a wide range of living organisms. These techniques are gradually replacing classical ...