Vol. 2 Issue 2
Ali A.F. Al-Furaih
Three new Maastrichtian ostracode species from the Aruma Formation outcrops that border Wadi al- Atj are described in this paper; namely, Acanthocythereis salehi, Clinocythese debile, and Pierygocythereis claustrata
A.M.A. Ismail, M. Obeid and M.E. Beshir
The composition of tree communities in the Fung-Area was assessed and sub-divisions into Riverine Associations and Clay Plain Associations were recognized. The former, with Zizphus spina-christi dominating , inhabit light soils with high water table and undulating terrain. The later are further subdivided into:
(i) Acacia Seyal - A. senegal - Balanites aegyptiaca associations in habitats where no cultivation is practised,
(ii) Acacia campylancantha - A. seyal- A. fistula and A. senegal in intensively cultivated areas,
(iii) Acacia mellifera associations in depressions and catchment areas,
(iv) Acacia nubica associations in over-grazed areas near villages and at the feet of rocky hills, and
(v) Combretum hartmannianum associations the probably relics of the original vegetation, present in areas least influenced by man.
It is concluded that the present distribution of tree species in the Fung area is largely the result of historical biotic influences rather than stemming from environmental effects.
A.M.A. Ismail, M. Obeid and M.E. Beshir
A study of the pattern of distribution of six tree species in the Fung area showed that species subjected to least human and animal interference tended to show the same pattern intensity in many sites. On the other hand, highly distributed species exhibited pattern intensity which varied between different sites. Physical environmental patterns provide special habitats for a number of species. Biotic interference appears to be most important factor determining the general distribution and abundance of the tree species in this area. The present patterns shown by species is attributed mainly to historical influences
Naim S. Ismail and Jamal Awad
The organic carbon and calcium carbonate content of sediments at the two sewage outfalls that release effluent into the northeastern tip of the Gulf of Aqaba have been determined and compared twice during 1982 and 1983
with control stations away from sewage pollution. The amounts of organic carbon in sediments at the outfalls and control stations are similar in their particle-size distributions and calcium carbonate content except the outfall near the phosphate loading port which has less calcium carbonate than its control station. Two additional stations, one on each side of the outfall, were examined. The sediments of these stations constantly have had higher values of organic carbon than the control stations, but lower than that at the outfalls
W.A. Bassali
An infinite series solution is obtained for the small deflection of a thin circular annular plate subject to symmetrical loading distributed over the entire plate and having several point supports which are situated at equal distances apart on a single concentric circle. Limiting forms of the derived solution are investigated
M. Luisa Targhetta
An inequality similar to the Bhattacharyya inequality is obtained in the presence of prior knowledge. Conditions under which equality holds are considered assuming a posterior density of the exponential type.
AJi Ahmad Fora
We shall define size functions and sizable spaces. These spaces are generalizations of metric spaces. We shall discuss some of their properties and then we discuss the metrizable space they induce under certain conditions on the sizable space. We shall also define open spheres and open balls and discuss the topologies they induce. Among the results we obtain, we have the following:
1) Every countably compact sizable space must be separable, and hence, it must have at most countably many discrete points.
2) Every countably compact sizable space induces a compact Hausdorff metrizable space which is weaker than the original topology. We shall also discuss the metrizability of countably compact spaces as an application of our concepts
H.A. Bokhary
Sclerotia of Sclerotinia sclerotiorum (Lib) De Bary were exposed to different humidities ranging from zero to 100% for different periods of time up to 168 hr. Leaching of carbohydrates occured after sclerotia were wetted. At zero and 33% relative humidities leaching of carbohydrates was highest and increased with period of exposure. Quantitative estimation of carbohydrates released showed that leaching was in the order trehalose, mannitol, glucose with fructose in trace amounts. On drying and rehydration of sclerotia at two relative humidities (zero and 100%) severe carbohydrate leaching occurred. Quantities leached were found to increase with the period of incubation at zero relative humidity but decreased with the period of incubation at 100% relative humidity.
Abou-Zeid A. Abou-Zeid and Mohamed A. Farid
Streptomyces spp. NRC-11 was isolated from Egyptian soils. The organism was identified and shown to be identical to Streptomyces collinus. It produced two antibodies in the fermentation broth. The two antibodies were separated, purified and subjected to identification. The physico-chemical and biological properties of antibiotics are reported. Antibiotics A-1 and A-3 from filtrate and mycelium respectively, were identical to gamma- rubromycin; antibiotic A-2 was identified as crotonic acid.
E.E. Shaisha, A.A. Bahgat and S.H. Salah
Experimental stress distribution for the forward ion exchange at two different temperatures 350 C and 500 C, obtained by successive slicing and photoelastic measurements, confirms the profiles calculated from the analogy to thermal stress theory and from finite element stress analysis. The measured profiles for the reverse field cases show much lower stresses than those predicted by the same theory. A theoretical analysis for the stress distribution calculated from the analogy to the thermal stress distribution and the effect of sample distortion due to slicing are briefly discussed.