Browsing Qatar University Science Journal - [From 1981 TO 2007] by Publication Date
Now showing items 21-40 of 770
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A Note on Norland Summability of Fourier Series
( Qatar University , 1982 , Article)In this paper we consider point-wise summability in the Norlund sense of Fourier series by assuming H(n) . F(n) = o (Pn) as n--+ oo, where (H(x) = d.x g(t) dt, g(t) is continuous, non-increasing, H(x) is slowly varying, ... -
Studies on Soil Cements: 1 - Role of Hydrated Lime and Dolomitic Monohydrate in Montmorillonite Stabilization
( Qatar University , 1982 , Article)Montmorillonite clay was stabilized by either hydrated lime or the dolomitic monohydrate (Ca(OH)2. MgO) during suspension hydration at 25 and 60°C for 45 days. The distinct phases produced from the hydration of each ... -
What is Graph Theory?
( Qatar University , 1982 , Article) -
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. ... -
Studies on Soil Cements : 2 — Physicochemical Properties of the Hardened Soil Cement Pastes.
( Qatar University , 1982 , Article)Various hardened soil-cement pastes were prepared from dry mixtures of montmorillonite clay and portland cement clinker by using different W/C ratios of 0.20, 40, 0.60 and 0.80 and cured in air for various ages. Compressive ... -
Blood Gases of some Skink Lizards
( Qatar University , 1982 , Article)(1) Po2 and Pco2 of arterial and venous blood are studied in three skink lizards: the bean skink, Mabui quinquetaeniata, inhabiting the cultivated areas, and the two burrowing desert lizards; the ocellated skink, Chalcides ... -
Insect Pests Attacking Vegetable Crops in the State of Qatar (Abstract)
( Qatar University , 1982 , Article)The area cultivated with vegetable crops in the State of Qatar reached, during 1979 and 1980, a percentage of about 42.9 % of the total cultivated (or suitable to be cultivated) area. Vegetable crops selected for collecting ... -
Mossbauer Effect Study of the Cations Distribution and its Influence on the Electric Field Gradient of the Cdx Co1-x Ferrite System
( Qatar University , 1982 , Article)In the ferrite system Cd,Co,_x Fe; 04 (X=0.0, O.I, 0.2, ....... , 1.0). it was found that the introduction of Co2'1' decrease the EFG at the octahedral B-site. This was attributed to the distributions of the different ... -
The Complexation of Lanthanides by Azo-B-Diketones Stability Constants
( Qatar University , 1982 , Article)The stability constants of the complexes between the trivalent lanthanide series of cations and series of azo-B-diketone ligands are reported. The measurements were conducted at 30°C and zero ionic strength (free KN03), ... -
Neutron Diffraction and Mossbauer Effect Study of a Cobalt Substituted Zinc Ferrite
( Qatar University , 1982 , Article)The mixed cubic ferrite Zno.g5 €00.15 Fez 04 is studied by neutron diffraction and Mossbauer effect techniques at the temperature range 4.2 - 293 °K. The obtained spectra by both methods at low temperature show a long range ... -
Microfacies of the Upper Cretaceous-Lower Tertiary Rocks of Um Rijam Area, South Jordan
( Qatar University , 1982 , Article)This paper deals, for the first time, with the microfacies of the Upper Cretaceous - Lower Tertiary rocks of south Jordan. Twenty three microfacies associations are recognized, described, discussed and illustrated. This ... -
Interpretation of Gravity Anomalies Due to Lens-Shaped Structures
( Qatar University , 1982 , Article)One of the interesting exploration problems in hydrogcology is finding subsurface geological lens-shaped structures. This paper deals with the interpretation of such structures using their gravity anomalies. A master curve ... -
Petrographic Studies of the Alamein Dolomite (Lower Cretaceous) in El-Razzak Oil Field, Western Desert, Egypt
( Qatar University , 1982 , Article)The origin and environment of deposition of the Alamein Dolomite in the El-Razzak Oil Field have been investigated by means of petrographic, chemical and X-ray analysis. The studied rocks are composed of dolomite with ... -
Study of the Hydration of Blast-Furnace Slag Cement and Portland Cement by Mossbauer Spectroscopy
( Qatar University , 1982 , Article)Mossbauer spectra have been measured for the hydrated blast-furnace slag cement and Portland cement pastes at different times of hydration of 1. 3. 7. 28 and 90 days. The spectra showed the existence of iron atoms, Fe3 (T) ... -
Coralline Algae from the Neoegne and Pleistocene Sequence of Mersa Alam, Red Sea, Egypt.
( Qatar University , 1982 , Article)Ten speciecs of family Corallinaceae (Coralline Algae) are herein recorded and described for the first time from the stratigraphic sequence of Mersa Alam, Red Sea, Egypt. Of these, Amphiroa knolli, Jania johnsoni and ... -
On Using the One-Exposure Method for Stress Measurements by X-Rays in Technology and Scientific Research
( Qatar University , 1982 , Article)The paper discusses the connection between macroscopic internal stresses and the technological character of technical materials. The basic theoretical relations which are used with X-Ray tensiometry of macroscopic internal ... -
Generalized Airy's- and taylor Integral Functions
( Qatar University , 1982 , Article)In this paper a generalized form of Airy's function has been estimated and an asymptotic expansion for one of its types is obtained. Furthermore, an improved formula could be induced to acquire the asymptotic expansion of ... -
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 ... -
Air-Borne Fungi Of Wheat Fields In Egypt
( Qatar University , 1983 , Article)The air borne fungi of wheat fields in El-Minya Governorate were studied during the periods January-May 1977 and December 1977-May 1978 using the plating catch method on 1% glucose and 50% sucrose-Czapek's agar. Fifty-two ... -
Seasonal Fluctuation Of Non-Rhizosphere Soil Fungi In Wheat Fields In Egypt
( Qatar University , 1983 , Article)The study aims at intensive survey of fungal floras of non-rhizospheric soil in wheat fields in El-Minya Governorate over the periods December 1976 - May 1977 and December 1977 - May 1978. At 28°C, using 1% glucose-Czapek's ...