Characterization of some bacterial strains isolated from the Egyptian eastern and northern coastlines with antimicrobial activity of Bacillus zhangzhouensis OMER4     

Mohamed O.Soliman  Waleed B.Suleiman  Mohamed M.Roushdy  Eman N.Elbatrawy  Ahmed M.Gad 《海洋学报(英文版)》2022,41(3):86-93

Marine microorganisms were considered to be important sources of marine bioactive compounds. The major objective of the study was to isolate and characterize bacteria with antimicrobial activities from the various marine environment of Egypt. In this respect, thirty-five bacterial isolates were recovered from sediment samples collected from different spots along the Egyptian Red Sea coastline and Alexandria coastline during the summer season of 2017 and 2018. According to the morphological, phys...  相似文献   

A new least-squares minimization approach to depth and shape determination from magnetic data     

El-Sayed M. Abdelrahman  Eid. R. Abo-Ezz  Khalid S. Essa  T.M. El-Araby  Khaled S. Soliman 《Geophysical Prospecting》2007,55(3):433-446

We have developed a least‐squares minimization approach to depth determination using numerical second horizontal derivative anomalies obtained from magnetic data with filters of successive window lengths (graticule spacings). The problem of depth determination from second‐derivative magnetic anomalies has been transformed into finding a solution to a non‐linear equation of the form, f(z) = 0. Formulae have been derived for a sphere, a horizontal cylinder, a dike and a geological contact. Procedures are also formulated to estimate the magnetic angle and the amplitude coefficient. We have also developed a simple method to define simultaneously the shape (shape factor) and the depth of a buried structure from magnetic data. The method is based on computing the variance of depths determined from all second‐derivative anomaly profiles using the above method. The variance is considered a criterion for determining the correct shape and depth of the buried structure. When the correct shape factor is used, the variance of depths is less than the variances computed using incorrect shape factors. The method is applied to synthetic data with and without random errors, complicated regionals, and interference from neighbouring magnetic rocks. Finally, the method is tested on a field example from India. In all the cases examined, the depth and the shape parameters are found to be in good agreement with the actual parameters.  相似文献   

Petrogenesis,Geodynamics and Radioactivity of the Granitic Rocks of the Nugrus Weakness Zone,South Eastern Desert,Egypt     

Soliman ABU ELATTA Abdallah Mahmou  Gehad M.R. MANSOUR 《《地质学报》英文版》2021,95(4):1183-1198

The studied granitic bodies belong to the south Eastern Desert of Egypt. They extend in a NNW–SSE trend along the same strike of the Nugrus weakness zone by which they are structurally controlled. These rocks are composed of biotite and biotite-muscovite monzogranites to syenogranites. Geochemically, a higher abundance of Ba and Rb in biotite granites with a relatively low abundance in biotite-muscovite granites as well as the diversity of Th, U, Nb, Ta, Zr, and REE reflects their origin from different sources and geodynamic settings. The biotite granites are predominantly metaluminous to low peraluminous whereas the biotite-muscovite granites have a peraluminous nature. Potassium enrichment at the expense of calcium in these rocks reflects a derivation from crustal sources by partial melting in the presence of a volatile system. Radiometric investigation showed high abundances of U(up to 38 ppm) and Th(up to 26 ppm) in biotite-muscovite granites relative to biotite granites(up to 5 ppm U and 18 ppm Th). Radioactive anomalies furthermore have been recorded in parts of biotite-muscovite granites that were affected by the faults(up to 116 ppm eU and 97 ppm eTh). Consequently, biotite-muscovite granites form a potentially fertile source for uranium mineralization.  相似文献   

The transboundary non-renewable Nubian Aquifer System of Chad,Egypt, Libya and Sudan: classical groundwater questions and parsimonious hydrogeologic analysis and modeling   总被引：2，自引：2，他引：0  

Clifford I. Voss  Safaa M. Soliman 《Hydrogeology Journal》2014,22(2):441-468

Parsimonious groundwater modeling provides insight into hydrogeologic functioning of the Nubian Aquifer System (NAS), the world’s largest non-renewable groundwater system (belonging to Chad, Egypt, Libya, and Sudan). Classical groundwater-resource issues exist (magnitude and lateral extent of drawdown near pumping centers) with joint international management questions regarding transboundary drawdown. Much of NAS is thick, containing a large volume of high-quality groundwater, but receives insignificant recharge, so water-resource availability is time-limited. Informative aquifer data are lacking regarding large-scale response, providing only local-scale information near pumps. Proxy data provide primary underpinning for understanding regional response: Holocene water-table decline from the previous pluvial period, after thousands of years, results in current oasis/sabkha locations where the water table still intersects the ground. Depletion is found to be controlled by two regional parameters, hydraulic diffusivity and vertical anisotropy of permeability. Secondary data that provide insight are drawdowns near pumps and isotope-groundwater ages (million-year-old groundwaters in Egypt). The resultant strong simply structured three-dimensional model representation captures the essence of NAS regional groundwater-flow behavior. Model forecasts inform resource management that transboundary drawdown will likely be minimal—a nonissue—whereas drawdown within pumping centers may become excessive, requiring alternative extraction schemes; correspondingly, significant water-table drawdown may occur in pumping centers co-located with oases, causing oasis loss and environmental impacts.  相似文献