Browsing Qatar University Science Journal - [From 1981 TO 2007] by Title
Now showing items 640-659 of 770
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Solvent Effects Of The Oxidation Of Iron (II) - Tartrate Complex By Molecular Oxygen In Aqueous Solutions Of Alcohols
( Qatar University , 1985 , Article)The solvent effects on the oxidation of Fe(II)-tartrate by molecular oxygen have been investigated in aqueous acidic solutions of alcohols such as methanol, ethanol, isopropanol and t-butanol. The second-order rate constant ... -
Some Adsorption Characteristics of Sodium decyl and dodecyl Sulphates on the surface of Emulsifier-free Polymer Latex Particles
( Qatar University , 1997 , Article)The adsorption characteristics of sodium decyl and dodecyl sulphates on polystyrene latex particles have been investigated. The study involves the addition of known amounts of the surfactant to an emulsifier-free latex, ... -
Some Aspects Of Camouflage In Animals
( Qatar University , 1989 , Article)Camouflage is the principal device by which vulnerable animals escape predation. The attention of potential predators can be avoided by protective resemblance -mimicking an inedible object such as a seed or leaf. Concealment ... -
Some Aspects Of The Autecology Of Panicum Turgidum Forsk
( Qatar University , 1983 , Article)The germination of Panicum turgidum seeds was tested under different conditions. They showed ability to germinate under a range of temperatures from 25-42°C. The maximum percentage of germination was 45%, at 30°C. The ... -
Some Enzymatic Activities Of Fungi Isolated From Cotton Seeds And Cotton Seed Products
( Qatar University , 1984 , Article)Five hundred different cultures which belong to fifteen genera and forty-one species, isolated from cotton seeds and cotton seed products were studied for proteolytic, amylolytic and lipolytic activities. About 80% of the ... -
Some Histological And Histochemical Aspects Of Egg-Implantation In The Rat
( Qatar University , 1987 , Article)The rat embrayo and uterine epithelium were studied during implantation at 129h p.c., 138h p.c. and 153h p.c., stages. The basophilic bodies found in the iiinpr cell mass and in the uterine epithelium represent dead cells ... -
Some Inferential Problems in Finite Population Sampling
( Qatar University , 2004 , Article)We review some results in problems of estimating a finite population total (mean) through a sample sur¬vey. Section 2 considers inference under a fixed population model and Section 3 addresses the same prob¬lem when the ... -
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 ... -
Some Oceanographic Measurements In The Gulf Waters Around Qatar Peninsula
( Qatar University , 1983 , Article)During the winter of 1979/1980 four cruises were made to the study area. Salinity, temperature and current speed and direction were measured. The areal distribution, as well as the vertical distribution of these parameters ... -
Some Properties Of Class Zw
( Qatar University , 1987 , Article)In paper |5| it was established Ilic inajorant w. Bill ex.iinples or a func'lion f £ Zw'were not coiistruclecl. In Illis |)is()er, in llie case of a snioolli closed curve, an example of such a function is constructed. -
Some Results Concerning Cobb - Voxman's Conjecture
( Qatar University , 2000 , Article)In this paper we shall give some partial results of the following conjecture raised in [3]: Suppose that X is a connected space with a dispersion point p and let f: X —> X be a nonconstant continuous function. Then f(p) = p. -
Some Unique Characteristics Of The Indian Ocean
( Qatar University , 1999 , Article) -
A Special System Of Boundary Value Problems
( Qatar University , 1987 , Article)In this paper we introduce a special system of boundary value problems and give a method for solving it. Then we give a detailed application of this method to a system of boundary value problems of Hilbert type. -
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. ... -
Spectroscopy in Corrosion Studies of Copper
( Qatar University , 1994 , Article)Spectrophotometric measurements were used to study corrosion of copper in aqueous solutions containing the four following depolarizers: K2Cr2O-j, K2S2O8, Fe(NH4)(SC>4)2 and CCI3COOH. A silica cell was used for the corrosion ... -
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 ... -
Sponges in Qatari waters A new source of marine natural products for biological applications
( Qatar University , 1999 , Article)Sponges are the most primitive multicellular organisms belonging to Animalia kingdom. They lack symetry and do not have differentiated tissues or organs. However, as a consequence of this primitive organization it is very ... -
Spore Colour Index And Organic Thermal Maturation Studies On The Pliocene Sediments Of The El Qara-2 Borehole, Nile Delta Area, Egypt
( Qatar University , 1996 , Article)Eight conventional core samples from the El Qara-2 well, situated in north central Nile Delta area, Egypt, have been palynologicaly investigated for determining the thermal maturity of the Pliocene Abu Madi and Kafr El ... -
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. ... -
Stability of Logistic Autoregressive Model
( Qatar University , 2007 , Article)In this paper we propose a Logistic Autoregressive Model, which is a special case of polynomial Autoregressive Model. The aim of this paper is to study and find the stability conditions of the above model by using a dynamical ...
