Qatar University Science Journal - [From 1981 TO 2007]: المرسلات الحديثة
السجلات المعروضة 341 -- 360 من 770
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Distribution, Genesis And Thermal Behaviour Of Clay Minerals In The Miocene Argillaceous Rocks In Qatar, Arabian Gulf
( Qatar University , 1989 , Article)XRD and DTA were utilized to investigate quantitatively the clay-mineral composition of the argillaceous rocks in four Miocene stratigraphic sequences located in western and southwestern Qatar. These rocks belong to the ... -
Synthesis of some new oximes, thiocarbamates, pyrazolyloxy, isoxazolyloxy, Pyrmidyloxy and pyridyloxy quinolines
( Qatar University , 1994 , Article)The reaction of 1 or its corresponding chalcones 3a-c with hydroxylamine in boiling pyridine gave the oximes 2 or 5a-c respectively in almost quantitative yield. When both 2 and 5a-c were reacted with phenylisothiocyanate, ... -
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 ... -
Ecological Characteristics Of The Littorial Fauna At Tubli Bay, Bahrain
( Qatar University , 1995 , Article)Papers presented at The gulf symposium on Environmental biology, University of Qatar, 7-9 May 1994 *********** The intertidal fauna inhabiting a wide range of habitats at Tubli, an inshore bay on the eastern part of ... -
Some Macrobenthic Invertebrates in the Qatari Waters, Arabian Gulf
( Qatar University , 2005 , Article)Macro-invertebrates from eleven stations along the Qatar Exclosive Economic Zone (EEZ), Arabian Gulf, were studied during December 1998. A total of 52 species were encountered from all stations. Crustaceans were the most ... -
The Mineralogy and Chemistry of Urinary Stones from the United Arab Emirates
( Qatar University , 1999 , Article)The purpose of this study is to characterize urinary stones from the United Arab Emirates using mineralogical techniques and compare it with stones in nature. Twenty six urinary calculi were subjected to chemical analysis, ... -
Chemical Factors Affecting Growth and Development of Lateral Root Formation in Isolated Phaseolus vulgaris L.
( Qatar University , 2007 , Article)The initiation and subsequent emergence of lateral roots as secondary roots have been examined in attached and excised roots of Phaseolus vulgaris grown in the absence or presence of indol-3-yl acetic acid (IAA). Treatments ... -
Combined effects of oxygen, partial vacuum, temperature, humidity and gamma radiation on mating competitiveness of culex pipiens complex l. Males
( Qatar University , 1993 , Article)When the pupal stage of Culex pipiens complex L. male mosquito was exposed to gamma radiation (60 Gy), oxygen, partial vacuum (0.1 torr), low temperature (10°C), for one or two hours, or low humidity (31% R. H.) for 3 ... -
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 ... -
The Flora of The State of Qatar: Its History and Present-Day Status
( Qatar University , 2005 , Article)The history of botanical exploration in the State of Qatar is of recent origin. Various collections culminated in 2 major Floras for the State of Qatar in 1981 and 1983. Since then, further collections and focus on several ... -
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) ... -
p-cds/n-Si Anisotype Heterojunction solar cells wih Efficiency of 6.4%
( Qatar University , 2005 , Article)In the present paper, p-CdS/n-Si heterojunction solar cells are prepared for the first time by the spray pyrolysis technique. Using such low-cost method, cells with 6.4'/o AM1 conversion efficiency ina O.ZZ fill factor ... -
The Optical and Electrical Properties of Low Density Polyethylene Films in CuSo4 Solution
( Qatar University , 2005 , Article)The optical and electrical properties of pure and treated low density polyethylene (LDpE) were investigated. These measurements have been carried out at various times of immersion for LDPE films in 10% solution of CuSO+. ... -
Numerical Abundance And Species Diversity Of Surface Zooplankton In The Coastal Waters Of United Arab Emirates On The Arabian Gulf A Preliminary Study
( Qatar University , 1999 , Article)Surface zooplankton of the coastal waters of the United Arab Emirates was studied bimonthly during the period September 1997 to July 1998. Species diversity, numerical abundance and seasonal dynamics were analyzed , at six ... -
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 ... -
Evaluation of Electron Swarm Parameters in SF6 Using Monte Carlo Method
( Qatar University , 2005 , Article)The motion of electrons in sulfur hexafluoride (SFo) in uniform electric fields is simulated using a Monte Carlo method. The swarm parameters are evaluated and compared with experimental results of drift velocity, electron ... -
Population biology of sparid fishes in qatari waters. 1 - reproductive cycle and fecundity of longspine seabream, Argyrops spinifer (Forskal)
( Qatar University , 1993 , Article)The reproductive cycle, gonads maturation, gonado-somatic indices (GSI) and fecundity of longspine seabream Argyrops spinifer from the Arabian Gulf waters off Qatar were investigated. Bi-weekly samples representing all age ... -
Biochemical Composition Of The Squid (Loligo Vulgaris) (Mollusca) From The Mediterranean Waters Off Alexandria, Egypt
( Qatar University , 1996 , Article)The seasonal biochemical variations of the squid Loligo vulgaris from the Egyptian Mediterranean waters off Alexandria were studied during November 1989 through August 1990. Water, lipid, protein and ash contents were ... -
Preliminary Assessment of the Effect of Saline Water Used in Irrigation on the Growth of the Local Barley Cultivar (Harma)
( Qatar University , 2001 , Article)ABSTRACT The effect of gradual increase m soil salinity, using diluted solutions ofseawater, on growth and yield of the local barley cul-tivar (Harma) was examined. Harma barley did not withstand osmotic shock higher than ... -
Geochemical Model And Normalization For Heavy Metals In The Bottom Sediments, Dubai, UAE.
( Qatar University , 1999 , Article)Dubai creek can be considered as the focal point of Dubai. It has great importance for trading and aesthetic values. Total and leachable heavy metals (Cd, Co, Ni, Pb and Zn), organic carbon and total carbonate were studied ...
