Browsing Qatar University Science Journal - [From 1981 TO 2007] by Subject "Chemistry"
Now showing items 61-80 of 95
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Photocatalytic treatment of industrial wastewater
( Qatar University , 1997 , Article)A novel Plexiglas double-skin sheet reactor ( DSSR ) able to use diffuse as well as direct sunlight for the detoxification of industrial wastewater was used. The efficiency of the photocatalytic treatment of a highly ... -
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 ... -
Phytochemical Studies On The Marine Algae Of Qatar, Arabian Gulf
( Qatar University , 1990 , Article)The most dominant twenty three algal species representing the main three groups of benthic macroalgae, Chlorophyceae, Phaeophyceae and Rhodophyceae were collected from the coastal zones of the Qatar peninsula. These algae ... -
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 ... -
Proton And Carbon-13 Nuclear Magnetic Resonance Of Some 4-Amino-3-Alkyl (Aryl)-5-Thio-1,2,4-Triazolines And Their Derivatives
( Qatar University , 1991 , Article)The proton and carbon-13 NMR spectra of some 4-amino-3-alkyl(aryl)-5-thio-1,2,4-triazolines, some 3-alkyl-5-thio- 1,2,4-triazolines and some 4-amino-3-aryl-5-thio-l,2,4-triazoles were measured in DMSO-d6 as solvent. The ... -
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 ... -
Pyrrolizidine alkaloids from heliotropium arbainense and h. Ovalifolium
( Qatar University , 1991 , Article)Investigation of the pyrrolizidine alkaloids of Heliotropium arbainense resulted in the isolation and identification of heliotrine, europine and 7-angelylheliotrine. From H. ovalifolium three alkaloids were isolated: ... -
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 ... -
Red cell superoxide dismutase in patients with different liver diseases
( Qatar University , 1995 , Article)Supcroxidc dismutase (SODs, supcroxidc oxidoreductasc, E.C. 1.15.1.1.) activity has been estimated in red blood cells from patients suffering from liver cirrhosis and hcpatoccllular carcinoma. Erythrocytcs supcroxide ... -
Serum And Tissue Enzymes And Trace Elements In Hamsters With Schistosomiasis Mansoni And/Or Protein Energy Malnutrition
( Qatar University , 1996 , Article)Schistosomiasis is mostly widespread in communities suffering from protein energy malnutrition. The development of an animal model for each condition is required for better understanding of changes in certain biochemical ... -
Solvent Effects Of The Oxidation Of Iron (II) - Tartrate Complex By Molecular Oxygen In Aqueous Solutions Of Alcohols
( Qatar University , 1985 , Article)The solvent effects on the oxidation of Fe(II)-tartrate by molecular oxygen have been investigated in aqueous acidic solutions of alcohols such as methanol, ethanol, isopropanol and t-butanol. The second-order rate constant ... -
Some Adsorption Characteristics of Sodium decyl and dodecyl Sulphates on the surface of Emulsifier-free Polymer Latex Particles
( Qatar University , 1997 , Article)The adsorption characteristics of sodium decyl and dodecyl sulphates on polystyrene latex particles have been investigated. The study involves the addition of known amounts of the surfactant to an emulsifier-free latex, ... -
Spectroscopic Studies On Some Methylphosphonothioic Diamides And Related Compounds
( Qatar University , 1987 , Article)A series of methylphosphonothioic diamides MrP (S) (NHR)., ( R = Mr, pr' and Bu') and some related compounds viz, PhP(S)(NHBu)a ,P1^P(S) ( NHCHJ'h ) arc preparpd and their infrared, n.m.r. and mass spectra arc- recorded. ... -
Stability Constants of Lanthanide Complexes with some Structurally Related Organic Ligands
( Qatar University , 1982 , Article)The stability constants of the complexes formed between trivalent lanthanide ions and related carboxyphenylhydrazo-B-diketones ligands are repoted, at 30 °C and at constant ionic strength (0.1 KN03), in 75 % dioxane-water. ... -
The Structures And Mode Of Formation Of Some Cyclodiphosphazane Derivatives With Urea And Thiourea
( Qatar University , 1986 , Article)The methods of preparation and possible reaction mechanisms for the formation of some geminal and nongeminal aminocyclodiphosph (v) azanes of the type (II - V) are discussed. These cyclodiphosphazanes obtained from the ... -
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 ... -
Studies on Soil Cements: 1 - Role of Hydrated Lime and Dolomitic Monohydrate in Montmorillonite Stabilization
( Qatar University , 1982 , Article)Montmorillonite clay was stabilized by either hydrated lime or the dolomitic monohydrate (Ca(OH)2. MgO) during suspension hydration at 25 and 60°C for 45 days. The distinct phases produced from the hydration of each ... -
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 ... -
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 ... -
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 ...