Browsing Qatar University Science Journal - [From 1981 TO 2007] by Title
Now showing items 748-767 of 770
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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 ... -
Ultrastructural Study Of Type "B" Neurosecretory Cells In The Earthworm Nervous System
( Qatar University , 1991 , Article)Neurosecretory cell types Bi—B5 are widely distributed throughout the cerebral, subesophageal, nerve cord and peripheral ganglia of the oligochaete Aporrectodea caliginosa, Lumbricus terrestris, Eisenia foetida, Octolasion ... -
The ultrastructure of some stages of haemogregarina Tarentannulari infecting the gecko Tarentola annularis
( Qatar University , 1995 , Article)Certain blood and schizogonic stages of Haemogregarina larentannulari - occuring in the vertebrate host Tarenlola annularis - were studied by electron microscopy. Certain crylhrocytic stages, as well as some schizogonic ... -
Urea Hydrolysis and Urease Activity in Saudi Arabian Soils
( Qatar University , 2000 , Article)Soil samples were collected from eight different localities m Saudi Arabia, and analysed for mechanical properties as well as for urea hydrolysis. The urease enzyme activity of these calcareous soils was also investigated. ... -
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 ... -
Variation Of The Electrical Properties Of Manganese Thin Films With Deposition Conditions
( Qatar University , 1989 , Article)The behaviour of the electrical properties of manganese thin films of different thickness (240 - 1500 A) evaporated under different deposition conditions was studied. The effect of the rate of evaporation (1-7 A/s), the ... -
Vertical Distribution And Inter-Relations Of Oxygen And Nutrients In The Arabian Gulf And The Gulf Of Oman In Summer
( Qatar University , 1990 , Article)The distribution patterns of oxygen and nutrients (phosphate, nitrate, nitrite and ammonia) were studied along the Arabian shelf of the Arabian Gulf and the Gulf of Oman, including the Strait of Hormuz, during September, ... -
Vibrational Analysis Of TaBr5
( Qatar University , 1987 , Article)Vibrational analysis for TaBr5 is achieved on the basis of D3h symmetry and employing GF matrix method. Each vibration is quantitatively assigned according to the calculated values of the potential energy distributions. ... -
Viscous Behavior of Dilute CMC Salt Solution Before and After Photodegradation
( Qatar University , 2006 , Article)Photodegradation curve of carboxymethylcellulose (CMC) in aqueous solution has been reported. Densities and solution viscosities of very dilute CMC salt solution before and after UV-irradiation have been measured. ... -
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 ... -
Volatile Components of the Phaeophyceae Hormophysa cuneiformis Growing Along Qatar Coasts
( Qatar University , 2007 , Article)The present work deals with the study on volatile compounds from the brown alga Hormophysa cuneiformis collected from the Northwest coast of Qatar on May 2002. Two extraction methods have been used: conventional hydrodistillation ... -
Water Conditions And Proline Content In Shade And Sun Plants
( Qatar University , 1984 , Article)Different parameters of the water conditions (Water content, water saturation deficit, osmotic pressure of the cell sap and partial osmotic pressure due to sugars), chlorophyll and proline contents were investigated in sun ... -
Water Quality Of The Area West Of Karak City, Jordan
( Qatar University , 1986 , Article)The water quality of some wells, wadis and springs in the area west of Karak City has been evaluated for irrigation and domestic uses, by the application ofWilcox (1955) and Doneen (1961) methods, as well as the standards ... -
Water Relations Of Some Woodlice (Oniscidea) From Arid And Mesic Environments
( Qatar University , 1987 , Article)The desert woodlouse Porcellio evansi from Bahrain and Qatar has a transpiration rate as low or lower than recorded from other desert species. The synanthropic mesic Porsellionides pruinosus has a much higher rate, while ... -
Weed Communities Of Date Palm In Eastern Arabia
( Qatar University , 1992 , Article)The present study deals with the recognition and description of the weed communities of date palm plantations in Al-Hassa Oasis, . Eastern Arabia. Thirty three communities are recognized. They are classified, after the ... -
What is Graph Theory?
( Qatar University , 1982 , Article) -
Whole-rock powders and their analysis by an electron mocroprobe technique
( Qatar University , 2001 , Article)Basic rock powders finder than 100 mesh were fushed in a molybdenum and tungsten boat in nitrogen atmosphere. The fusion technique uses very small amounts of sample which is suitable for rapid analysisof rock sample, ... -
Window Analysis Optimization Of Gas Chromatographic Separation Using Different Polarity Packed Columns
( Qatar University , 1996 , Article)Window diagram theory has been described by Purnell and his research team in various publications. In this paper we apply this theory to optimize a separation of complex mixture containing propylene oxide, 1-hexene, ... -
X-Ray And Electron Microprobe Analysis Of Some Plagioclases From The Jabal Abu Safiyah Intrusion
( Qatar University , 1992 , Article)The Jabal Abu Safiyah is a layered intrusion, which was emplaced within volcanosedimentary rocks. It extends in an arc for about 15 km and displays clear layering. The lower zone plagioclases were studied by electron ... -
y - Irradiation Effect On The Ferroelastic High Temperature Phase In LiKSO4 Crystals
( Qatar University , 1992 , Article)The effect of •y -irradiation on the thermodynamic parameters of LiKSC>4 single crystals, in the high temperature range 300-1000 K, is investigated. The results show that T,; as well as Cp decrease with dose rate. However, ...
