Browsing by Subject "Chemistry"
Now showing items 81-100 of 106
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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 ... -
Synergistic effect of expanded graphite, diammonium phosphate and Cloisite 15A on flame retardant properties of EVA and EVA/wax phase change blends
( Springer , 2015 , Article)The influence of the introduction of expanded graphite (EG), as well as combinations of EG with Cloisite 15A clay and diammonium phosphate (DAP), into EVA and an EVA/wax blend on the thermal stability and flammability of ... -
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 ... -
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 ... -
Synthesis And Reactivity Of Substituted Chromones
( Qatar University , 1992 , Article)The synthesis of 2-methyl-and 2-Styryl-6-bromo-7, 8-benzochromone and 2, 6-Dimethylchromone and their reactivity towards cyclo-addition reaction under Diels-Alder conditions and towards nucleophilic and electrophilic ... -
Synthesis And Spectroscopic Properties Of Some Mixed-Ligand Complexes Of Nickel (II), Copper (II), Zinc (II) And Palladium (II) With Biologically Active Nitrogen-Sulphur Containing Molecules
( Qatar University , 1990 , Article)The reaction of the biologically active complexes, chloro-2-acetylpyridinehyd-razinecarbothiopiperidinamide metal (II) and chloro-2-acetylpyridinecar-bothiomorpholinamide metal (11),^, (M=Ni (II), Cu (II), Zn (II) and Pd ... -
Synthesis and Spectroscopic Studies ofAtenolol Derivatives with Enhanced Lipophilicity as Potential Prodrugs
( Qatar University , 2002 , Article)Atenolol, a selective pi-adrenoceptor blocking agent is characterized by its low bioavailability. A number of atenolol prodrugs were synthesized to improve its lipid solubility and hence bioavailability. These compounds ... -
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 ... -
Thermogravimetry and infrared spectroscopy Of Moroccan oil shales in an oxidative Dynamic atmosphere
( Qatar University , 1994 , Article)Thermogravimetric analyses were carried out on raw Timahdit (Morocco) oil shales and its demineralisation products in an oxidative atmosphere. The kerogen was isolated by successive HCl, HF and float-sink separation ... -
Thermometric Study of Inhibition of Aluminium Corrosion in Hydrochloric Acid Solution
( Qatar University , 1997 , Article)The use of 6- amino - 4- (4-phenyl)-l,4- dihydro -3- methylpyrano [2,3- c] pyrazole -5- carbonitrile and some related compounds as corrosion inhibitors for aluminium in 2 M HCl solution was studied by the thermometric ... -
Toxic Effect Of Lannate On Cellular Defence System In Erythrocyte Of Rat
( Qatar University , 1996 , Article)Lannate 1 - methomyl was incubated with erythrocytes of rats at different concentrations. It has been observed that there was a decrease in the activities of superoxide dismutase and glutathione reductase after 1/2 and 16 ... -
Trace Metals in Wastewater Ponds in Qatar
( Qatar University , 2002 , Article)A one-year monitoring program was conducted to determine the extent of metal contamination in two wastewater ponds in Qatar. Abu-Hamour pond receives untreated domestic and industrial waste while Abu-NakhIa pond receives ... -
Transmetalation Mechanisms
( Qatar University , 1993 , Article)Transmetalation is the stoichiometric replacement of the metals in a polymetallic target T with different metals from reagents called transmetalators, TM. Transmetalation at useful rates under mild conditions is an excellent ... -
Triaryl And Trialkyl Phosphites As Corrosion Inhibitors For Copper In Nitric Acid
( Qatar University , 1992 , Article)Some triaryl and trialkyi phosphites were investigated as inhibitors of the corrosion of copper in nitric acid. The values of inhibitor efficiency from weight-loss measurements are in good agreement with those obtained ...