Qatar University Science Journal - [From 1981 TO 2007]: Recent submissions
Now showing items 441-460 of 770
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Electrical Properties Of The Lower Eocene Rocks In Qatar
( Qatar University , 1987 , Article)Thirteen limestone samples representing the Rus Formation (Lower Eocene) are selected' from four locations in Qatar Peninsula. These samples are subjected to electrical resistivity, porosity, shaliness factor and water ... -
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+. ... -
Threshold Modelling Of Ship's Dynamics
( Qatar University , 1995 , Article)In this paper we consider an application of a system called threshold system in the field of marine engineering. Properties of this system are discussed and the idea of the impulse response function of threshold system is ... -
The Possible Effects of Some Mineral Nutrients and Industrial Chemical Effuents on Wild Plants in Central Sudan
( Qatar University , 2006 , Article)The effects of some mineral nutrients and industrial chemical effluents from a textile factory and tanning activities on the growth and distribution of Typha angustata, Cyperus laevigatus. Paspalum viginatum, Cassia senna ... -
Vitamin - a and limb regeneration in stages of the egyptian toad, bufo regularis Reuss-histological study
( Qatar University , 1995 , Article)The histogenesis of regenerated limbs, of both control and treated /larvae/ with 30 I.U./ml of retinol palmitate for 3 days, was studied in two larval stages (viz. stages 53 & 54) of the anuran amphibian, Bufo regularis ... -
Ultrastructural localization of acid and alkaline Phosphatases, glucose-6-phosphatase and odium-potassium Atpase enzymes in the neurosecretory and oesophageal Cells of earthworm
( Qatar University , 1994 , Article)In the present study we have localized acid and alkaline phosphatases, glucose-6-phosphatase and sodium-potassium ATPase (Na-K-ATPase) in ultra-thin sections of cerebral neurosecretory cells and oesophageal cells of the ... -
Photoperiod and salinity effects on survival and some blood parameters in female Bufo regularis
( Qatar University , 1986 , Article)This study, investigates the effect of different salinities injected (30, 70 and 100 % sea water) and photoperiods (L:D/8:16,L:D/12:12 and L: D / 16 : 8 ) on female Bufo regularis (1) survival rate, (2 ) oxygen and carbon ... -
On Symboloic Reasoning and Direct Inference Principle
( Qatar University , 2004 , Article)This paper discusses an approach using the M-valued symbolic logic with syllogistic reasoning and direct inference principle (reasoning from statistical information to conclusions about individuals), to manipu¬late statistical ... -
Study of Magnetic Properties and Lattice Dynamics of the Cdx Co1-x Ferrite System by MossbauerEffect
( Qatar University , 1981 , Article)The magnetic properties and lattice dynamics of the spinel ferrite system Cdx Coi-x Fe^ 04 (x = 0.0, 0.1, . . . , and 1.) were studied in the temperature range between 78 to 800°K. The results showed that the samples with ... -
Partial characterization Of an alkalophilic extracellular Crude pectinases from a bacillus Polymyxa strain
( Qatar University , 1999 , Article)A mesophilic spore forming isolate from the soil of Um-Qais region, which could produce extracellular pectinases was tentatively identified as Bacillus polymyxa. This bacterium grew best at 37°C and pH 7.0 and was able to ... -
Evaluation of quaternary aquifer between qena and luxur. (Nile Valley, Egypt)
( Qatar University , 2001 , Article)In order to evaluate the hydrogeological setting of the Quaternary aquifer and the related geological structures controlling its characteristics. A total of 50 vertical electrical soundings (VES.s) were conducted along 13 ... -
Lithofacies and depositional environments Of the lower jurassic sediments In central Saudi Arabia
( Qatar University , 1999 , Article)The lithofacies, microfacies and sedimentary environments of the surface Lower. Jurassic sediments in central Saudi Arabia are studied. The Lower Jurassic is represented by the marine clastic Marrat Frormation which is ... -
Geologic evolution of the Dukhan salt flats in Western Qatar Peninsula, Arabian Gulf
( Qatar University , 2003 , Article)Photo-interpretation of landsat Thematic Mapper images of the Dukhan salt flats, on the west coast of Qatar, reveals several deposit zonations within the salt flats. The deposit zonations occupy a restricted sub-evaporite ... -
A Mixed Markovian Time Series Model
( Qatar University , 1997 , Article)We study a simple time series model the noise properties of the proposed model are derived. An algorithm based on the conditional mean and the conditional variance, for estimating the parameters of the proposed model is ... -
Empirical Investigation Of Wave Velocities In Bahariya Formation, Western Desert, Egypt
( Qatar University , 1994 , Article)In the Meleiha Oil Field, Western Desert of Egypt, eleven selected drilled wells were chosen to investigate the seismic velocities in the Bahariya Formation. The velocity-depth relations were studied and equated. The ... -
Microdetermination Of Some Organic Nitriles Using The Cyanide Ion Selective Electrode
( Qatar University , 1985 , Article)The response characteristics of the solid state cyanide ion selective electrode toward some organic nitriles are investigated. In 10 M KOH solution, the electrode exhibits near Nemstian response over the range of 10~2 to ... -
The Inhibitive Action Of Sodium Soya Sulphonate Towards The Corrosion Of Aluminium In Hydrochloric Acid
( Qatar University , 1993 , Article)The dissolution of aluminium in 2M hydrochloric acid in the presence of sodium soya sulphonate (SSS) as corrosion inhibitor has been studied using hydrogen evolution and thermometric methods. The two methods gave consistent ... -
Studies On Bottom Trawling And Demersal Fishes Of Qatar Waters, Arabian Gulf
( Qatar University , 1989 , Article)The bottom trawl fishery and their by-catch from Qatar waters were analysed on a systematic basis for species composition, length, weight and girth-among other things-during the year 1986-1987. The resuls proved a steady ... -
Concerning Sequential Spaces
( Qatar University , 1985 , Article)In this paper, important notions concerning sequential spaces are clarified new ideas, one of which is a complete and direct proof of the fundamental theorem characterizing sequential spaces, are introduced. -
Analysis of dopant diffusion in molten germanium induced by pulsed nd : yag laser
( Qatar University , 1995 , Article)Laser - induced diffusion of various dopant elements into intransic germanium based on the dipping of Ge into dopant solution, have been used to produce doped ge layer using yag pulse laser with 300us duration ( A, = 1.664(1 ...
