Vol. 3 Issue 1
Mostara M. Soliman
Albitization and greisenization processes are recognized in certain zones in the tin-bearing granites of the Southeastern Desert of Egypt. These alteration processes are usually followed by hydrothermal activities and are not observed in the non-stanniferous granites. Albitization of of magmatic and/or post-magmatic processes, whereas greisenzation is formed by post-magmatic. Greisenization resulted in the destruction of the feldspars of the granites and the formation of quartz, muscovite, lepidolite, topaz, fluorite and cassiterite. This is accompanied by partial migration of Na, K, Ca, Fe, Ti, Y, Zr, Be and Pb and the addition of Si, F, H2O, Sn and Nb. Albitization is manifested by the growth of fine to medium-grained albite, sometimes with beryl. This is accompanied by the addition of Na, Be, Sn, Nb, Cu, Mo and Bi and partial migration of Si, Fe, Ti, Y and Zr. Fluoride complexing is an important factor in element mobility and transportation during greisenization and albitization. Carbonate and fluoride complexing are the most plausible cause of element mobility in hydrothermal processes giving rise to quartz veins.
Mostafa M. Soliman
Geochemical stream sediment surveys were carried out in the Samiuki-Hamata area of the Southeastern Egyptian Desert. Results indicate that in prospecting for Cu the fine fractions of the stream sediments (<0.075mm) are suitable for cold extraction technique, and the coarser fractions (<1 and <0.25 mm) are more suitable for spectrographical analysis. The soluble Cu ranges from 0.6 to 7% of the total Cu suggesting that mechanical dispersion of Cu is dominant and chemical dispersion plays a limited role in the development of the secondary dispersion trains and halos in this arid conditions. Spectrographical analysis of the -0.5 + 0.25, -0.25 + 0.15 and -0.15+ 0.075mm fractions of the stream sediments gave the best contrasts for Ni, Cr and Mo, respectively, indicating differences in their geochemical patterns. The reconnaissance stream sediment survey revealed a pattern of Cu distribution that is relatable to known mineral occurrences. Cr, Co and Ni are coprecipitated and are probably related to a common source material such as the mafic-ultramafic ophiolites. The Cu mineralization probably had a volcanic origin. The mineralized zones were then remobilized by late-stage Ca and Mg-bearing hydrothermal solutions associated with the rejuvenation of deep fault zones, resulting in the present association of Cu and talc mineralization within shear zones.
A.A. Al-Sobebany
The group of units of the integral group ring Z[A4] has been determined by Allen, P.J. and Hobby, C. In this note we use a different method to give a description of it, namely we consider Z[A4] as a module over the ring of integer Z. Since Z[A4] has a finite rank which is |A4|, therefore we construct a Z-basis for it and we use this basis to described Z[A4] and Characterize its group of units.
A.G. A.G. Babiker
Let D be the total number of Schistosomiasis eggs produced by an individual in a day, counting only those eggs which leave the body, and let S denote the number of eggs observed on a slide under the microscope and p the probability that a given egg ends up in a given slide. Assuming that D follows a negative binomial distribution, the distribution of S and that of D given S are studied.
Explicit expressions for the coordinated mean and variance of D given S and for the probability of a false negative slide are obtained. Two different cases are considered. In the first case, p is assumed to be constant, and in the second, more general case p is assumed to follow a beta distribution. In either case, the probability of a false negative slide, which is a measure of the insensitivity of the laboratory test, is shown to ultimately decrease with the degree of clumping of the daily egg excretion D.
S.A. Al-Salman
In this paper we prove that Sn is a (2, 3, 16)- group for 16<=N<= 25, and that An is a (2,3,16)-group for N=23 and 18 <= N<=25.
Emad El-Rayes, Ales Prokop, Rashad M. Natour and Howard D. Ratcliffe
compost microflora, mostly thermophilic, isolated during various stages of composting municipal refuse in Kuwait (mainly composed of food waste and cardboard), consisted of dominant bacteria in counts of 10^4 - 10^9 g^-1, followed by actinomycetes at 10^4 - 10^8 g^-1. Among these microbial groups, some isolates were identified to the species level, some to the genus level. Based on semiquantitative test of extracellular protein accumulation, the total number of fungal isolates (21) was reduced to six prospective ones. Further screening of fungi was based on assays of cellobiase, carboxymethylcellulase (CMCase), filter paper and cotton activity, following growth on different carbon sources. A comparison was also made with other available fungi or with published date. Cellobiase and CMCase activities of some KISR strains were comparable or superior to those published, other activities were rather low.
H.A. Bokhary
Succession of coprophilous fungi has been studied on camel dung (Camelus dromedarius L.). Faecal pellets, which were incubated moist initially for a period of 75 days, were then dried at room temperature for 225 days and thereafter reincubated in moist chambers for 30 days. Twenty eight species belonging to twenty genera of coprophilous fungi were observed. Among the fungi examined, seven species showed profuse sporulation both in the pre- and post drying period, whereas three species were recorded only during the post-drying period. Mucor circinelloides appeared during both the pre- and post-drying period.
Vijay K. Arora
Quantum theoretical results on dc transport in quantum well wires (QWW) indicate the suppression of ionized impurity scattering under stronger quantum confinement conditions, with enhancement of acoustic-phonons or point-defect or alloy scattering. The quantum size resonance linewidth, when radiations are polarized perpendicular to the wire, is shown to be proportional to lambdaD^2/A(tau)b where lambdaD is the de Broglie wavelength, A is the confinement area, and tau b is the bulk relaxation time. A quantum freeze-out of confined carriers is expected to induce a semimetal-semiconductor transition in semimetallic thin wires.
T. El Dessouki, I. Fouda, F. Sharaf and N. Khalil
An empirical formula is applied to relate laser-induced damage to single metallic films to their thermal properties. The dependence of the resulting damage into targets of double metallic layers on their thicknesses is investigated. The damage into the double layer target is found to be four times greater than its value for the corresponding thickness in the single layer case, when the laser powder pulse is kept constant
M.I.A. Al-Mehdi
The structure of the retina of the light adapted fish Cyprinion macrostomus has been studied by light microscopy, and this revealed that the basic plan of retinal structure resembles that of other freshwater fishes, except for certain specific differences and specialization which are also noted in this study. The pigmented epithelium is composed of a single layer of cuboidal cells with long processes filled with extensive melanin pigments. The contact of the epithelial cell processes with the outer segments of the visual cell are also noted and correlated with the retinomotor reponses. The slender rod cells are distributed singly or in clusters among the cone cells. the latter are of five types: short and long singles, equal and unequal doubles and occasional triple cones. These cones are often arranged in a well defined square mosaic pattern in tangential sections. This pattern may reveal the degree of retinal development. The lipid-like droplets have been observed in the scleral part of the cone ellipsoid. The present finding has been discussed in the light of existing knowledge about the occurrence of different cone types and oil droplets in the retina of different freshwater fishes.