Browsing by Subject "Chemistry"
Now showing items 41-60 of 106
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Flavonoids From Cressa Cretica
( Qatar University , 2005 , Article)The aerial parts of Cressa cretica L. yielded five flavonoids that were identified as quercetin (1), quercetin-3-B-O-D-glucoside (2), kaempferol-3-O-B-D-glucoside (3), kaempferol-3-O-a-L-rhamno-(1—+6)- B-D-glucoside (a) ... -
Formation of Usual and Bridging Complexes using organoselenium and -Tellurium compounds
( Qatar University , 2005 , Article)The reactions of l,3-benzoselenadiazole with some diiodo selenium and tellurium heterocyclic compounds have led to the formation of charge transfer complexes. From the same reactions but in the presence of I9PtC14 new types ... -
Gc-ms analysis and antimicrobial activity of volatile oil of Pituranthos tortuosus (desf.)
( Qatar University , 1995 , Article)Volatile oil of Pituranthos tortuosus (Desf.), family Umbelliferae was prepared in yield of (0.5%). GC-MS analysis of the oil resulted in identification of eight components. Dill apiole was the main constituent (94.76%). ... -
Heat Absorbers based on Recycled Polyethylene and Paraffin Wax for Energy Storage
(2016 , Master Thesis)The building sector is one of the main sectors in Qatar; however, it consumes a huge portion of primary energy sources. Today, there is a worldwide trend to utilize renewable sources of energy to cover buildings’ energetic ... -
Heavy metals concentrations in Otolithes ruber and Pampus argenteus location from the Gulf
( Qatar University , 1999 , Article)For dermination of the Concentration of six heavy metals ( Cu, Fe, Mn, Zn, Cd, Pb) in the muscle of Oyuber and Py argenteus. Eighty samples were collected from north Qeshm Island in the Persian gulf. For digestion of samples ... -
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 ...
