Browsing Qatar University Science Journal - [From 1981 TO 2007] by Subject "Chemistry"
Now showing items 41-60 of 95
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Heterocyclic Aminoacrylate Esters Of Potential Biological Activity
( Qatar University , 1985 , Article)This work describes the synthesis of N-substituted piperidyl 2-benzoxazole acrylates (la-d); 2-benzothiazole acrylates (2a-d); 2-furyl acrylates (3a-d) and 2-thiophene acrylates (4a-d). The esters of 3-quinuclidyl (Ie, 2e, ... -
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. ... -
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 ... -
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 ... -
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 ... -
The inhibitive action of sodium castor sulphonate Towards the corrosion of aluminium in Hydrochloric acid
( Qatar University , 1993 , Article)The dissolution of aluminium in 2M HC1 solution in presence of sodium castor sulphonate (SCS) has been studied using thermometric and hydrogen evolution methods. The results showed that the additive retards the dissolution ... -
The Inhibitive Action Of Sodium Soya Sulphonate Towards The Corrosion Of Aluminium In Hydrochloric Acid
( Qatar University , 1993 , Article)The dissolution of aluminium in 2M hydrochloric acid in the presence of sodium soya sulphonate (SSS) as corrosion inhibitor has been studied using hydrogen evolution and thermometric methods. The two methods gave consistent ... -
Inhibitory Effect Of Some Oc —Aminocarboxylic Acids On Corrosion Of Aluminium In Hydrochloric Acid Solution
( Qatar University , 1992 , Article)The corrosion of metallic aluminium in 2N hydrochloric acid solution in the presence of L-alanine, L-tyrosine, L-histidine and L-tryptophan as corrosion inhibitors has been studied using hydrogen evolution and thermometric ... -
Investigation of Magnesium (II), Calcium (II) and Barium (II) Complexes in Aqueous Solution
( Qatar University , 2005 , Article)The ionic association constants, K6, of Mg, Ca and Ba metal ions with succinate, malate and tartrate ligands were conduct metrically determined in water at 25-40°C. The conductometric data were analysed by the Shedlovsky ... -
Kinetics and Mechanistic Studies of the Bromination of Some Substituted Tetralones, Part 1
( Qatar University , 2000 , Article)The rate of bromination of 2-benzal-l-tetralone (II) and its derivatives p-methyl (12), 77-chloro (13), ffi-chloro (14), and p-nitro (15) have been studied in chloroform. The study indicated first order dependence on each ... -
Mechanism of Dehydration of Ethanol over Alumina
( Qatar University , 1981 , Article)The dehydration reaction of ethanol to ether and ethylene was kinetically investigated in a flow system using •y-alumina. Pyridine was found to inhibit the formation of ethylene and ether. The rate of ethylene formation ... -
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 ... -
Methylated Flavonoids From Artemisia Monosperma
( Qatar University , 1989 , Article)Investigation of the flavonoid constituents of Artemisia monosperma resulted in the isolation and identification of four methylated flavonoids: quercetin 3,3',4'-trimethylether, diosmetin (luteolin 4'-methylether), ... -
Microdetermination Of Some Organic Nitriles Using The Cyanide Ion Selective Electrode
( Qatar University , 1985 , Article)The response characteristics of the solid state cyanide ion selective electrode toward some organic nitriles are investigated. In 10 M KOH solution, the electrode exhibits near Nemstian response over the range of 10~2 to ... -
A New Liquid Membrane Electrode For Selective Determination Of Caffeine
( Qatar University , 1984 , Article)A new liquid membrane electrode for caffeine prepared from a solution of caffeine-picrylsulfonate ion-pair complex in n-octanol is developed. It exhibits Nernstian response in the range of 10'2 to lO^M caffeine with a ... -
A New Tetrafluoroborate Liquid Membrane Electrode For Selective Determination Of Boron
( Qatar University , 1986 , Article)The construction and performance characteristics of a new liquid membrane electrode selective for BF^ion are herein described. The electrode incorporates nitron-tetrafluoroborate ion pair complex in nitrobenzene as a liquid ... -
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 ... -
A Packed Column Gas Liquid Chromatographic Method For Characterization And Determination Of Unsaponifiable Matter In Oils
( Qatar University , 1991 , Article)A packed column GLC method for the detection and determination of the components of unsaponifiable matter in oils is described. Squalene, 8 -tocopherol and short chain hydrocarbons with up to 26 carbon atoms are determined ... -
Parathormone, Calcium And Phosphorus In Autotransplanted Parathyroid, Total Thyriodectomized Patients
( Qatar University , 1995 , Article)The success of parathyroid autotransplantation was indicated by the postoperative assay of serum parathormone in thirteen out of fourteen patients to whom total thyroidectomy was carried out because of thyroid cancer during ... -
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 ...