Browsing QU Ceased Journals by Title
Now showing items 188-207 of 2240
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Constituents of catha edulis (alkaloids, triterpenoids and related substances and saponins)
( Qatar University , 1989 , Article)The study of the alkaloids of khat samples from Egypt and Yemen revealed qualitative and quantitative differences. Cathine and the dimer of cathinone occured in both samples, while norephedine was detected only in Yemen ... -
Constituents Of Centaurea Species
( Qatar University , 1992 , Article)A comprehensive review of Centaurea species including all the isolated consituents is given. The biological activities of the studied species are also reported. -
Constituents Of Cymbopogon Species
( Qatar University , 1986 , Article)A comprehensive review of the Cymbopogon species including the essential oils and their constituents is given. An account of the other components viz. non volatile terpenoids and phenolic compounds is also given. The ... -
Constituents Of Green Beans Phaseolus Vulgaris (Lipids And Flavonoids)
( Qatar University , 1992 , Article)Chemical study of the lipid fraction resulted in the isolation and identification of a hydrocarbon fraction (n-Czg -0-033); an aliphatic alcohol fraction (C^, Czp, €30) and a sterol fraction (stigmasterol and sitosterol). ... -
Constituents of plants growing in qatar part xxvii: flavonoids Of cymbopogon parkeri
( Qatar University , 1995 , Article)The study of the flavonoids of Cymbopogon parkeri resulted the isolation and indentification of tricin and isoorientin. Three other flavonoids have been isolated and partially identified. -
Constituents of plants growing in qatar x.* seasonal variations of the volatile oil of cymbopogon parkeri
( Qatar University , 1985 , Article)The seasonal variation of the volatile oil of Cymbopogon parkeri Stapf. was studied. The oil content is higher during the hot dry season than during the humid hot season and the cold season. No qualitative differences among ... -
Constituents of plants growing in qatar xxiii. Flavonoids of francoeuria crispa
( Qatar University , 1993 , Article)Investigation of the flavonoid constituents of Francoeuria crispa, resulted in the isolation and identification of four flavonoids: quercetin, qucrcetin-3-O-gIucoside, quercetin-7-0-glucoside and quercetin-3-methyl ether. -
Constituents of plants growing in Qatar xxiv phytochemical investigation of salvia aegyptiaca L.
( Qatar University , 1994 , Article)The study of the flavonoids revealed the isolation and identification of luteolin, luteolin 7-O- glucoside, apigenin and apigenin 7-0 glucoside; their identity was proved by m.p., TLC, UV, IR and MS. Moreover, a coumarin ... -
Constituents of plants growing in qatar xxv flavonoids of Picris Radicata (forssk.) Less.
( Qatar University , 1994 , Article)Four flavonoids were isolated from the plant and were identified as apigenin, chrysin 7-glucoside, leuteoline and luteolin 7-glucoside. -
Constituents of plants growing in Qatar: part xxviii. Constituents Of cistanche phelypaea
( Qatar University , 1995 , Article)Ten compounds were isolated from the methanolic extract of the aerial parts of Cistanche phelypaea (Orobanchaceae) and identified as echinacoside (1), tubuloside A (2), tubuloside E (3), acteoside (4), 2'-acetylacteoside ... -
Construct Validity in Psychology and Educational Measurement
( Qatar University , 1992 , Article) -
Construction Simulation Using Virtual Reality
( Qatar University , 1996 , Article)Two main simulation methodologies namely, the network-based simulation and the graphical simulation technique are being used in the construction industry. While the network-based simulation technique, which was originally ... -
Continued Fractions Evaluation And Their Applications To Some Probability Distribution Functions
( Qatar University , 1995 , Article)This paper discusses some continued fractions in obtaining rational approximations to functions, emphasising those which are important in statistical applications. It will be shown that continued fractions are valuable ... -
Contribution Of Horizontal Drilling Technology In The Development Programs Of Saudi Oil Fields
( Qatar University , 2001 , Article)The technology of drilling and production of horizontal wells is probably one of the most significant breakthrough in the oil and gas industry of the eighties. The continuous improvement of hardware equipment made horizontal ... -
Contribution of the Fungal Flora and Mycotoxins of Some Canned Tomato Paste Samples
( Qatar University , 1994 , Article)Twenty-two species belonging to seven genera were isolated and identified from 21 tomato paste samples on glucose-Czapek's (5 genera and 14 species) and 10% NaCl-glucose-Czapek's (6 genera and 17 species) agar media, at ... -
Contribution To The Sedimentology Of The Bahariya Formation Of Gebel El-Dist, Bahariya Oasis, Western Desert, Egypt
( Qatar University , 1983 , Article)Combined microscopic, grain-size and heavy-mineral analyses were carried out on the Bahariya Formation at Gebel El-Dist (type section), Bahariya Oasis. These studies revealed that the formation is composed of moderately ... -
Control Algorithms Of Digital Automatic Voltage Regulators For Synchronous Generators
( Qatar University , 1990 , Article)The main concepts of the application of digital controllers to a power system as automatic voltage regulators are presented in this paper. An experimental study using a physical model of a limited size power system has ... -
Control of Void Formation During Forging of Advanced Fiber Reinforced Composite Materials
( Qatar University , 1989 , Article)Increased interest has emerged in recent years in the development of fiber reinforced superalloy composite materials and the fabrication processes to produce composite turbine vanes and blades for advanced gas turbine ... -
Convection In A Rotating Fluid Over A Sloping Bottom, With Application To The Arabian Gulf
( Qatar University , 1992 , Article)Convective motions over a sloping bottom driven by evaporation and freshening are investigated by integrating the complete momentum and mass conservation equations. The problem is posed as an initial value problem in a ... -
A convenient synthesis of Carbocyclic fused Thieno [2,3-b] Pyridines and Carbocyclic fused IH-Pyrazolo [3,4-b] Pyridines
( Qatar University , 2001 , Article)A synthesis of Carbocyclic fused thieno [2,3-b] pyridines and carbocyclic fused 1H- pyrazolo [3,4-b] pyridines utilizing car-bocyclic fused 2(lh)-pyridinethiones as starting components is described. The structures of the ...