Vol. 3 Issue 2
H. O. Sindi
This paper describes the field geology of the area to the north of the Al-Jibub which is bounded by 41 degrees 05' E- 41 degrees 10' E longitude and 21 degree 00' N- 21 degree 05' N latitude. The Jabal Al- Qunnah is a elliptical body measuring 10 by 6 km with its major axis trending 032 degrees. The area has been studied topographically using aerial photographs, spot heights and contour lines, and has been divided into four landform categories. The highest point is 1620 m while the lowest elevation is 1400 m above sea level. This area broadly consists of hills of moderate relief cut by narrow and broad wadis (mostly fault controlled) in which the more common sediments are generally coarse gravels with some sand. Wind blown sand forms local small dunes. Sand and gravels derived from the local outcrops occur in the nearby wadis and samples from the alluvium wadi deposits have been studied geochemically.
The solid geology consists of Bahah group metamorphics which are intruded by a large gabbro and peripheral ring granites. There are also numerous dykes, some of which are possibly of Tertiary age. To the west is a large granitic pluton that makes relatively low ground with a sand and gravel blanket through which small masses of weathered rocks arise. This granite cuts the gabbro and has a shear margin against it. The gabbro has been altered along shear zones and faults, and generally has developed a patchy greenschist facies metamorphic assemblage.
The gabbroic body shows relict layering on various scales including megalayers some 300 m thick. The structure of this layered, inverted cone intrusion has been studied in detail by making several traverses, as a result of which, the igneous pluton has been petrographically divided into six different lithological units, clinopyroxene gabbro An 65, hornblende- clinopyroxene gabbro An55, hornblende gabbro (with kaersutite and An48-52), olivine gabbro, leucogabbro An55, and gabbro pegmatite with dark prismatic amphibole. There is a general reduction in colour index upward within each layer and from layer to another, the igneous rocks are probably of late Precambrian age and the metamorphics were formed about 1100 m.y. age.
A development model has been postulated for the Al-Taif region which is applicable to the present area.
H. Khalifa
Six species belonging to four genera of fossil calcareous algae are here recorded, for the first time, from the Lower and Middle Eocene rocks west and northwest of Assiut, Nile Valley, Upper Egypt. Among these, the following three species are new; Neomeris mirensis n. sp., Neomeris johnson n. sp. and Girvanella aegyptiaca n. sp.
Three biozones, based on their microfossil content, are recognized through the Lower-Middle Eocene succession of the area.
A. Naeem, A. A. Almohandis and M.Y. Alsanussi
A study of underground water with regard to its use in agriculture is presented. The water samples were collected from the Riyadh region. The sources of these waters are Jubaila and Minjur aquifers. A hydrochemical study of these waters indicates that water from Minjur aquifer is more suitable for agricultural purposes, in terms of its salinity and alkali hazard, than the water from Jubaila aquifer. The boron concentration in these waters is less than 1 ppm, making it suitable for some sensitive crops, and all semi-sensitive and tolerant crops. The residual sodium carbonate (R.S.C) is <1, making it suitable for irrigation
A. Mahmoud and M. El-Tom
Hammada elegans, Suaeda monoica, Salsola tetrandra, Rhazya stricta and Dipterygium glaucum form important communities in the Jeddah-Makkah region. Climatic aridity, altitudinal moisture gradients, extensive grazing and competition all contribute to the pattern of distribution, structure and composition of the vegetation
S.A. Al-Salman
This is a sequel to an earlier paper by the author in which it was proved that the symmetric group Sn of degree N is a (2, 3, 16)- group for 16<=N<= 25 whereas the alternating group An is a (2, 3, 16)- group for 18<= N<= 25, N is not equal to 23. In this paper, it is proved that both Sn and An are (2, 3, 16)- groups for 26<= N<= 30
Muhammed A.S. Al-Mass'ari
The operation and characteristics of the (Ga(1-x) Alx) As/GaAs heterojunction solar cell are studied numerically in detail. The complete system of transport equations governing the behavior of this p-n device established and reformulated for computer calculation. Within a very thin top layer (below 0.2 micro) the conversion efficiency is computed to be 23.5% for x=0.8, provided that the junction depth is less than 0.5 micro. The depletion width at zero bias is determined to be 0.1 micron.
Although this cell type is quite costly, its predicted high AM0 efficiency makes it a promising candidate for both space and terrestrial concentrator applications
N.T. Taib and B.M. Jarrar
A comparative histochemical study on the distribution and localization of nine digestive enzymes in the alimentary tracts of the skink (Chalcides ocellatus), spiny- tailed lizard (Uromastyx microlepis) and the stripe-necked terrapin (Mauremys caspica) was undertaken. Variations in the activities and localization of these enzymes in the three reptiles are discussed in relation to their feeding habits.
Momtaz H. Ismail
The postembryonic development of the olfactory organs was studied in five developmental stages of the Nile cichlid fish Sarotherodon galilaeus (= Tilapia galilaea) including two buccal stages (5 and 7 mm) and three bostbuccal ones (9, 12 and 58 mm total length).
In the buccal stages, the olfactory organ on each side is simple and represented by the olfactory epithelium and a narrow olfactory chamber opening externally through a single aperture on the dorsolateral surface of the snout. As development proceeds in the postbuccal stages, however, two accessory nasal sacs are developed: a dorsomedial sac and a ventrolateral sac, both are connected with the main olfactory chamber. Based on the analysis position of the accessory nasal sacs, in relation to the surrounding skeletal parts of the head, the mechanism of water pumping may have been operated by the respiratory movements as well as movements of the jaws in opening and closing of the mouth.
Mikky A. Amoudi
The mice used in this study were a total of 42; they were divided into seven experimental groups. Each mouse was inoculated with 20,000 sporulated oocysts of Eimeria vermiformis. The results showed that hempa and thiotepa exert an effect on the mice bearing E. vermiformis when administered orally at the rate of 0.33 mg per mouse. Doses were calculated from the LD50 data for each of the drugs in mice. The doses of hempa apparently caused increased oocyst production. Peak oocyst discharge and patent period were found to be delayed in the treated groups. The doses of thiotepa was kept the same in all animals, but the time of administration was synchronized with the developmental stages of the parasite. It was found that by gradually increasing the duration of the drug administration, oocyst discharge was increased. Both drugs may affect the immune system of the mice and the recognition of antigen of the parasite. It could be useful to use these immunosuppressive agents to prolong the retention of transplant tissues in the body.
H.M.I. Hafiz, A.S. Larik and Y.A. Al-Saheal
The study of 40-chromosome progeny of the breeding material for establishing a monosomic series in Avena sativa cv. Manod (2n=6x=42) by backcrossing it with A. sativa cv. Borreck GM1-1, revealed the presence of 19 bivalents and 2 univalents in all the pollen mother cells (PMC's) of Av. 562/3/41/53 as compared to normal 20 bivalents per PMC. It is highly likely that the original monosome (Satellite-2, Hafiz 1978) has undergone monosomic shift. Furthermore, it disturbs other homoeologous chromosomes because of greater affinity compared to the homologous partner. The paper also discusses the implication of monosomic analysis for gene-chromosome association in practical plant breeding.