Qatar University Science Journal - [From 1981 TO 2007]: Recent submissions
Now showing items 201-220 of 770
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Fe57 Mossbauer Study In Cobalt Substituted Magnetite
( Qatar University , 1983 , Article)The Mossbauer effect has been studied in the mixed ferrites CoxFe3_x04 (for x = 0.8, 0.9 and 1) with the spinel structure in the temperature range between 78 and 830K. The composition with x = 1, showed an expected Zeeman ... -
Stratigraphy And Petrology Of The Eocene Rocks At Maghagha (East And West), Nile Valley, Egypt
( Qatar University , 1985 , Article)Combined paleontological and petrological studies on the Eocene rocks at Maghagha revealed that the succession belongs to one biostratigraphic zone; the Numrnulites gizehensis gizehensis zone. Nummulites striatus was ... -
Congenital Anomalies in Down Syndrome Among Qatari Population
( Qatar University , 2006 , Article)Down Syndrome (DS) is the major cause of mental retardation and congenital heart disease affecting the welfare of over 300,000 individuals and their families in USA. The aim of the study is to see which are the most common ... -
Foraminifera And Age Of The Araej Formation In The Dukhan Oil Field, Western Qatar Arabian Gulf
( Qatar University , 1992 , Article)The detailed examination of the three members of the Araej Formation (lower Araej, Uwainat and upper Araej) in four wells, in the Dukhan Field, led to the identification of 36 foraminiferal species. Of these, 29 species ... -
Harmful Effects Of Sea Water Administration On Kidney Structure And Function
( Qatar University , 1992 , Article)Ratlus rattus received oral int'usiuii „; 3 ml of sea water for 5 consecutive days. Certain blood parameters and kidney structure and function were studied 24 hours and one week later. Hematocrit. plasma osmolality, sodium, ... -
Bio Accumulation Of Chromium, Nickel, Lead And Vanadium In Some Commercial Fish And Prawn From Qatari Waters
( Qatar University , 1997 , Article)A total of 150 fish and prawn samples representing the most economically important species were collected during 1995-96 by experimental fishing in three locations covering the coastal waters of Qatar. Fish and prawn flesh ... -
ultrastructural observations on the effect of the insecticide "aldrin" on some neurosecretory cells of the cerebral ganglion of the earthworm aporrectodea caliginosa
( Qatar University , 1994 , Article)The effect of the insecticide "Aldrin" on the neuroglia and neurosecretory cells of the earthworm Aporrectodea caliginosa was studied. The fine changes on the organdies of certain neurosecretory cells was observed by light ... -
Studies On Some Fetal Rat Organs Following Maternal Hyperthermia
( Qatar University , 1993 , Article)The present investigation was carried out to determine the histological changes in brain, liver and kidneys of rat fetuses maternally heatstressed at early stage of pregnancy to either high "spiking" temperature of short ... -
Proteins of cottonseed (gossypium barbadense) .• extraction and characterization by electrophoresis
( Qatar University , 1995 , Article)The seed proteins of cotton (Gossypium barbadense) were quantitavely and qualitavely investigated. The qualitative study was carried out using different electrophoretic techniques ((PAGE, SDS-PAGE, Poro-PAGE, SDS-Poro-PAGE, ... -
On the Classical Multicolor Ramsey Number R(3,3,3)
( Qatar University , 2004 , Article)In this paper, we are interested in the problem of evaluation of the classical multicolor Ramsey number i?(3,3,3). We first convert it successfully into a system of clauses of 3-literals each, i.e., a 3-SAT instance. We ... -
Heterocyclo-sulpha drugs: part x. Novel 5-imino-a2-pyrazolin-4-ditfflocarbamyl-s-azo dyes as antimicrobial agents
( Qatar University , 1994 , Article)Synthesis of a series of novel azo-sulpha drugs as 5-imino-3-methyl-l-phenyl-A -pyrazolin-4-dithiocarbamyl-s-azo dyes (I-XV) are described by the reaction of 4-sulphamoyl and/or sulphonyl diazonium chloride with ... -
Synergistic effect of amino acids and chloride ion on adsorption On copper metal
( Qatar University , 1994 , Article)The effect of adsorption of a- alanine, P-alanine, DL-aspartic, L-glutamine, iso-leucine and L-lysine in 1 M HC1 solution on the corrosion of copper has been studied using the potentiokinetic technique. The examined amino ... -
Parasites As Indicators Of Environmental Change And Pollution In Marine Ecosystems
( Qatar University , 1999 , Article)Good biological indicators to monitor the effects of pollutants on marine organisms must be exceptionally sensitive to environmental change so that a significant reduction in their numbers can be used as a warning of ... -
Effect Of The Apical Ectodermal Ridge On Mitotic Index In Hind Limb Bud Mesenchyme In Bufo Regularis
( Qatar University , 1991 , Article)The apical ectodermal ridge (AER) was formed at stage 51 of Bufo regularis, it persisted at stage 52 (limb bud acquiring paddle-shaped outline), then it disappeared by stage 53 (first indication of fourth and fifth toes). ... -
Evaluation Of Soil And Water Resources In Wadi Wardan, Sinai, Egypt, Using Electrical Resistivity Method
( Qatar University , 1985 , Article)A number of 15 Vertical Electrical Soundings were carried out in the Delta of Wadi Wardan, on the western coastal zone of Sinai, about 55 km south of Suez. The study objectives were to find out the change in thickness of ... -
On A Relation Between Two Absolute Summability Methods
( Qatar University , 1997 , Article)In this paper we prove a theorem concerning a relation between the summability methods |R,pn,qnlJt and |R,un|fc , k > 1 , which generalizes a result of Bor [2]. -
Magnetic Studies on High - Tc Bi - Pb- Sr - Ca - Cu - O Ceramics
( Qatar University , 1997 , Article)The superconducting material with a nominal composition BiI 6 Pb0 4 Sr2 Ca2 Cu3 Ox has been recently synthesized and characterized by the authors using the Q- factor method. The Q-factor data reported in this work shows ... -
Preliminary Study on Coral Reef and Its Associated Biota in Qatari Waters, Arabian Gulf
( Qatar University , 1999 , Article)Coral reef grounds and their associated biota m Qatari waters were investigated by Scuba diving. Four selected reef-sites were studied. Coral was presented by 17 species. Descriptive notes of each site and an initial list ... -
Seasonal Fluctuations Of Certain Species Of Nocturnal Coleoptera As Indicated By A Light Trap At Quena
( Qatar University , 1985 , Article)1) One light trap of Robinson type fitted with a mercury vapour bulb was operated for two consecutive years. Eighty - three species were identified and counted. The most abundant species was Tachys fumigatus of which over ... -
Changes in Copepod Community Structure in Response to Land-Based Activities along Alexandria Coastline, Mediterranean Sea
( Qatar University , 2000 , Article)Along the coastal water of Alexandria, Copepods were collected from four different areas subjected to agricultural/industrial mixed discharge, primary treated sewage flow, industrial effluent and agricultural runoff to ...
