Qatar University Science Journal - [From 1981 TO 2007]: Recent submissions
Now showing items 581-600 of 770
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Geology, Petrography, Geochemistry And Petrogenesis Of The Egyptian Younger Granites
( Qatar University , 1990 , Article)One hundred and thirty nine new chemical analyses of major and trace elements for 26 plutons and masses pertaining to the Egyptian Younger Granites are presented together with the chemical analyses of 13 biotites, 32 ... -
Gravitohydrodynamic Instability Of A Streaming Fluid Cylinder
( Qatar University , 1996 , Article)The capillary-gravitodynamic instability of a self-gravitating fluid cylinder (radius R«) dispersed in a self-gravitating medium of negligible motion has been developed. General stability criteria are derived, upon utilizing ... -
Tectonic Setting and Petrogenetic Evolution of Wadi Erier Rocks, South Eastern Desert, Egypt
( Qatar University , 2003 , Article)A combination of geologic, petrographic and chemical criteria is used to classify the Erier basement rocks into three suites namely, the metagabbro-diorite (MGD) suite, the tonalite-granodiorite (TG) suite and the ... -
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 ... -
A study of contamination of the northern Jordan valley agricultural fields by various metal ions using regression analysis.
( Qatar University , 2000 , Article)Geochemical analysis were performed in lower subsurface soil samples of 10,20,30 and 40cm depth, collected from seven regions in the northern Jordan valley. Eighteen descriptors (variables) for each sample were used. Among ... -
Palaeozoogeography of Shallow Marine Ostracoda from Holocene Sediments-Southern Iraq
( Qatar University , 1999 , Article)The Holocene palaeozoogeography of southern Iraq (Southern Mesopotamian Basin) have been studied according to the distribution of thirteen species of shallow marine ostracoda belonging to twelve genera. Their distributary ... -
On The Behaviour Of The Solutions Of ff …...
( Qatar University , 1984 , Article)The above equation plays an important rote in the geometric theory of functions of a complex variable. To determine interval estimations for its solutions, an inequality is obtained using the fixed point theorem. Then, ... -
Detection Of Small Amounts Of Lard In Other Animal Fats
( Qatar University , 1993 , Article)The composition of fatty acids at the b-position (B-FA) and a, a' -positions of the. triacylglycerol was used to establish new criteria for the detection of small amounts of lard in other fats. Determination of P-FA was ... -
Biochemical Characterization Of Human Schistosomes And Their Molluscan Hosts By Electrophoretic Techniques
( Qatar University , 1994 , Article)The recent application of biochemical techniques in taxonomy markedly improved the specific identification and strain characterization of a wide range of living organisms. These techniques are gradually replacing classical ... -
Cytological Studies On The Effect Of The Herbicide "Dual" On Allium Cepa
( Qatar University , 1988 , Article)Dual is widely used in Egypt as an active herbicide against annual grass weeds in soybean, sunflower, sugar beet and maize. Cytological studies have been carried out to show the effect of the herbicide on cell division in ... -
The Superimprimitive Subgroups Of The Alternating Group Of Degree 8
( Qatar University , 1984 , Article)A transitive permutation group G is called superimprimitive if it is imprimitive with non-trivial block systems of imprimitivity of lengths all the non-trivial divisors of the degree of G; The superimprimitivity concepts ... -
The mineralogy and chemistry of cement and cement raw materials In the united arab emirates
( Qatar University , 1996 , Article)The raw materials, clinkers and cements from different cement factories in the United Arab Emirates have been investigated using polarizing microscopy, X-ray diffraction (XRD), Scanning electron microscopy (SEM), and ... -
Dehydration of Ethanol over HF-treated Al2 O3 using the GC-column as Chemical Reactor
( Qatar University , 1981 , Article)The effect of treating •y-alumina with hydrofluoric acid on the dehydration reaction of ethanol was investigated at 325°C. The gas chromatographic column was used as a chemical reactor. The rate of formation of ethylene ... -
Morphisms Of Affine Schemes And Equivalence Of Categories
( Qatar University , 1996 , Article)In this work we construct the relation between the category R-filt (G(R)-gr) and the category O^ — Filt(O^ — Gr). The quantum (ungraded) version of this result can be obtained by restricting to parts of zero degree. ... -
The Models of a General Component of a Distributed Computing Systems Based On Stochastic Petri Nets
( Qatar University , 1994 , Article)In this paper we propose models of a distributed computing system (DCS) based on general stochastic Petri nets (GSPN). We also propose the means to decrease the number of states. We indicate that the complexity of DCS ... -
Translation - invariant Positive-definite Generalized Kernels of Infinite Number of Variables
( Qatar University , 1981 , Article)In the theory of spectral analysis of positive-definite j<.ernels, there exist well-developed methods based on the ideas of Krein connected with the construction of a Hilbert space by means of a kernel [ 1, 11]. In the ... -
Variability Of Wind System And Its Expected Effects On Oil Slick Movement In The Arabian Gulf
( Qatar University , 1992 , Article)The marine data required for the models of the oil spill movement prediction (current and wind data) are discussed. The available water current data in the Arabian Gulf can not be used with confidence because of lack of ... -
Generation of Sets of Sequences lsomorphic to Walsh Sequences
( Qatar University , 2005 , Article)Walsh sequences of the order 2k, k positive integer, form an additive group generated by Rademacher sequences set of ft-order. Except the zero sequence, Walsh sequences form an orthogonal set. Our present work allows us ... -
Sponges (Porifera) In Submarine Caves
( Qatar University , 1999 , Article)Sponges (phylum Porifera) have the most simple and probably the most ancient body plan of the multicellular animals. They are, however, very successful in most benthic ecosystems. They are dominant in submarine caves, where ... -
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 ...
