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السجلات المعروضة 81 -- 90 من 96
HPLC and MS analyses of lutein-esters from tagetes patula L.
(
Qatar University
, 1996 , Article)
Investigation of the xanthophyll esters of Tagetes patula L. flowers resulted in the isolation and identification of lutein, lutein dimyristate, lutein myristate palmitate, lutein dipalmitate and lutein palmitate stearate. ...
Synthesis and Reactivity of Iron-Iridium Heterobimetallic Complexes Using Tridentate Phosphine Ligands
(
Qatar University
, 1994 , Article)
Treatment of {Fe (CO)3 {(PPh2) 2 C=CH2}] with PPh2H gives the addition product [Fe (CO)3 {(PPh2) 2 CHCH2 PPh2}] (1). The uncoordinated phosphine group of complex 1 reacts with Ir4 (CO)12 to give mono-, di- and tri-substituted ...
Pyrrolizidine Alkaloids From Senecio Aegyptius L.
(
Qatar University
, 1988 , Article)
Investigation of the alkaloidal constituents of Senecio aegyptius L. resulted in the isolation and identification of senecionine, dehydrosenkirkine and probably an isomer of seneciphylline. TLC, HPLC and GLC showed the ...
Synthesis, spectroscopic and thermal properties of some ionic polymers and polymeric complexes derived from phthaloyl bis (s-methylhydrazinecarbodithioate).
(
Qatar University
, 1990 , Article)
Mono- and bis hydrzides derived from the condensation of S-methylhyd-razinecabodithioate with benzoylchloride and tere- and iso-phthaloydichloride, respectively, were prepared. Their reactions with secondary ...
Preparation, Characterization and Structural Determination of some coordination compounds of quadridentae thiosemicarbazone
(
Qatar University
, 2004 , Article)
New transtion metal complexes of Co", Ni" and Cu" with benzil bis 4-(p-Chlorophenyl-thiosemicarbazone) and benzil bis 4-(p-Bromophenyl-thiosemicarbazone) were synthesized. Attempts were made to ascertain their probable ...
Copper Complexes Of Di-, Tri-, And Tetra-Peptides Containing Tryptophan, Histidine And Arginine
(
Qatar University
, 1983 , Article)
Fifty Seven copper complexes of di-, tri-. and tetra-peptides containing tryptophan, histidine and arginine are studied spectrophotometrically. The ^a, and colour of the complexes are dependent on the sequence of the amino ...
Influence of The Activated Qatari Attapulgite Clay Admixture on The Mechanical Properties and Hydration Kinetics of Ordinary Portland Cement
(
Qatar University
, 2001 , Article)
Blended cements are types of cements containing additives other than those used m Portland cement, which have considerable technological interest, because such addition increases the chemical resistance to sulfate and ...
Application of Stripping Voltammetry for the Determination of Cadmium, Lead, Copper and Zinc in Yemani soils and Vegetables
(
Qatar University
, 2004 , Article)
Heavy metals contents in the solutions from acid digestion of Yemeni soils and vegetables were deter¬mined by differential pulsed anodic stripping voltammetry. The geometric mean for Cd, Pb, Cu and Zn concentrations for ...
Aminoacid derivative? With psychotogenic activity by
(
Qatar University
, 1989 , Article)
As a part of an extensive programme concerned with the syntheses and investigation of a group of benzilyl-aminoacid and diphenylacetylaminoacid, piperidine esters possessing psychotogenic properties, attention has been ...
Viscous Behavior of Dilute CMC Salt Solution Before and After Photodegradation
(
Qatar University
, 2006 , Article)
Photodegradation curve of carboxymethylcellulose (CMC) in aqueous solution has been reported. Densities and solution viscosities of very dilute CMC salt solution before and after UV-irradiation have been measured. ...