Browsing by Subject "Chemistry"
Now showing items 61-80 of 106
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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 ... -
Novel composite materials of modified roasted date pits using ferrocyanides for the recovery of lithium ions from seawater reverse osmosis brine
( Nature Research , 2021 , Article)In this paper, novel composite materials from modified roasted date pits using ferrocyanides were developed and investigated for the recovery of lithium ions (Li+) from seawater reverse osmosis (RO) brine. Two composite ... -
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 ... -
(−)-Paniculatol, a new ent-labdane bromoditerpene from Laurencia paniculata
( Elsevier Science Ltd. , 1997 , Article)(−)-Paniculatol, 1, an unusual tricyclic bromoditerpene belonging to the ent-labdane series has been identified in the red alga Laurencia paniculata collected on Qatari coasts, Arabian Gulf. The structure displays an unusual ... -
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 ... -
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 ... -
Pyrolytic elimination of ethylene from ethoxyquinolines and ethoxyisoquinolines: a computational study
( Nature Research , 2023 , Article)This work reports a thermo-kinetic study on unimolecular thermal decomposition of some ethoxyquinolines and ethoxyisoquinolines derivatives (1-ethoxyisoquinoline (1-EisoQ), 2-ethoxyquinoline (2-EQ), 3-ethoxyquinoline (3-EQ), ... -
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, ...