Vol. 4 Issue 2
M.M. Dorgham and A. Muftah
The species composition of the phytoplankton community in the Arabian Gulf of the Qatar peninsula was studied. The presented data were obtained from the analysis of samples collected seasonally during 1984. A total number of 390 taxa were recorded including 225 diatoms, 152 dinoflagellates, 2 silicoflagellates and 11 blue green algae. The given table represents the first comprehensive list of phytoplankton species occurring in the Qatari waters
Loutfy Boulos and Redha Al-Hasan
Ten species, mostly weeds, are newly recorded from Kuwait and Bahrain, of which the desert annual Crassula alata (Viv.) Berger is the first Crassulaceae ever recorded from Kuwait and Eastern Arabia; the species is also new to the Arabian Peninsula
A.M.A. Ismail and A.H. Ali
A field experiment was conducted for two consecutive years during the crop season of 1980 and 1981 to investigate into the response of some morphological characters and grain yield of five rates of N and three times of application. Splitting relatively high nitrogen rates into two applications widely separated in time had no effect on plant height but had a significant effect on the number of days from sowing to 50% flowering and grain yield. High yields of irrigated sorghum can be obtained if N fertilizer (145-160 kg/ha) was split into two halves and applied 21 days and 45 days from sowing the crop
M. Y. Khuhawar
Bis (acetylacetone) meso-stilbenediimine and bis (acetylacetone) DL- stilbenediimine form colored copper (II) and nickel (II) chelates. Copper (II) complexes are not sensitive spectrophotometrically, but the nickel complexes show reasonable sensitivity. Similarly TG and DTG studies indicate that nickel complexes are relatively more volatile and thermally stable than corresponding copper chelates. The metal complexes can easily be gas chromatographed from OV101, 3% on chromosorb (80-100 mesh size) column. Calibration range, detection limits and resolution of copper and nickel complexes are reported. The nickel complexes also show higher sensitivity with lower detection at ng levels than corresponding copper complexes
A.M. El-Naggar, F.S.M. Ahmed, A.M. Abd El-Salam, M.S.A. Latif and H.M. Abd El-Bary
The synthesis of 4-(N-Tos- and N-Pht-aminoacyl)- aminopyridines (III-XIV) and 2-(N-Pht-aminoacyl)- aminopyrimidines (XV-XXIV) has been achieved employing the acid chloride and carbodiimide methods. Hydrazinolysis of 4-(N-Pht- Gly-or- Beta-Ala-) aminopyridines or 2-(N-Pht-L-Phe-or-Beta-Ala-) aminopyrimidines in ethanol afforded the desired 4-(Gly-or-Beta-Ala) aminopyridines (XXV-XXVI) amd 2-(L-Phe-or-Beta-Ala) aminopyrimidines (XXVII-XXVIII) respectively. 4-(N-Pht-or-N-Tos-dipeptidyl) aminopyridines (XXIX-XXXVI) are synthesised via the DCC method, and 2-(N-Tos-L-Val-L-Leu) aminopyrimidine (XXXVIII) via the azide method. The 2-(aminoacyl) aminopyrimidine derivatives (XV, XVI, XXI, XXII, XXVIII and XXXVII) and the 4-(aminoacyl)-aminopyridine and derivatives (XXV, XXVI) are found to possess various antimicrobial and antiungal properties (as compared to I & II) towards diferent microorganisms with MIC values ranging from 5 to 250 micrograms/ml.
A.A. Al-Suhybani and G. Hughes
The radiolysis of 2,5-dichlorohydroquinone (H2QCl2) at different pHs leads to no change in the system. The addition of some alcohols leads only to a small removal o H2QCl2. This was taken to indicate an efficient back reaction. The saturation of H2QCl2 with N2O leads to the formation of 2,5-dichlorobenzoquinone (QCl2). It yield is dependent on dose and it increases with pH being a maximum in the pH range 2.1- 2.8. A satisfactory agreement is obtained between G(QCl2)calc. and G(QCl2)meas. upto pH ~2.1. At higher pH, the low yields were taken to indicate a back reaction involving N2O- and semiquinone radical (HQCl2). In the presence of H2O2, QCl2 is also produced. Its yield is dependent on radiation dose, [H+], [H2O2] and [H2QCl2]. This system has indicated that, in addition to the oxidation of H2QCl2 by OH perhydroxyl radical (HO2) can also oxidize H2QCl2 and possibly HQCl2. Whatever the reaction mechansim may be, it is concluded that H2QCl2 has a strong resistance to radiation damage
Jaber S. Mossa, Mobamed S. Hifnawy and Abdel G. Mekkawi
Qualitative phytochemical similarly in date seeds of seven Saudi Arabian cultivars was observed, as the samples were found to contain sterols, sugars, flavonoids, minerals, and fixed oils. Microbiological and neuropharmacological screening, with the alcoholic extract of one cultivar, showed significant antimicrobial activity against certain microorganisms as well as a stimulant action on the motor activity of mice.
El Sayed A.A. Youssef
The pyritic, glauconitic, and dolomitic facies within the Coniacian- Santonian sequence of the Abu Zenima area, west-central Sinai, Egypt, display characteristic post-depositional, chemical, mineralogical and textural changes. These changes are mostly attributed to bacterial activity and weathering. The studied microfacies are represented by thin layers of ferruginous pyrite-biomicrite, ferruginous glauconitic oolite, mottled dolostone, and ferruginous glauconitic quartz arenite. The ferruginous ooids are generated in place from the weathering of glauconite grains, whereas the mottled character of the dolostone is produced by the oxidation of ferrous iron released from ankerite and glauconite grains by weathering. The ferruginous materials are composed mainly of hematite. goethite and lepidocrocite.
Mostafa M. Soliman
Geochemical rock sampling and panning of Alluvium suggest the occurrence of a geochemical province of beryllium, in which beryl is the main beryllium mineral, in the Nugrus-Zabara area. The province lies in a NW-SE belt parallel to a deep-seated tectonic zone of the Red Sea trend and extends for about 40 km from Um Kabu in the SE to Zabara in the NW. The province is restricted to certain horizons of mica schists and quartz veins in contact with greisenized and albitized stanniferous granites and is probably developed by pneumatolytic and hydrothermal fluids (developed during the evolution of stanniferous granite magma) which moved along deep-seated tectonic zones. The province is characterized by biotitization, tourmalinization and silicification of the schists and increased concentrations of Be, Sn, Nb, Pb, Y and Cu in the granites, schists, quartz veins and pegmatite dykes. The ancient emerald mines are located within the boundaries of this province
M.M. Nasralla and A. Younes
Monitoring programme was conducted in Muna Valley during muslims pilgrimage period, 1402 H (1982 G). Measurements of sulphur dioxide, ammonia and particulates were carried out at the middle of the most busiest place in the valley. The rate of dustfall during pilgrimage period was 294 mg m-2 d-1 while its background rate was found to be less than 90 mg m-2 d-1. Concentrations of sulphates and tarry matter in dustfall were more than three times higher than their concentrations in dustfall over the area after pilgrims departure. Sulphur dioxide and suspended particulate were found associated at high concentrations enough to create health problems for those who are suffering from bronchitis and other chest troubles. High concentration of ammonia detected are possibly one of the prime causes of throat irritation during pilgrimage period.
The results of the present work confirm that the atmosphere of Muna Valley is favoring the accumulation of pollutants to the limits causing adverse health effects for pilgrims. Control measures should be adopted and environmental planning for Muna Valley should be considered. These measures are urgently needed to avoid air pollution episodes in the valley during the occupancy of more than 2 million persons