Current State of Crustal Deformation and Seismic Activity from Seismic and Geodetic Data in Aswan Region,Egypt     

Mohamed  A.-M. S.  Radwan  A. M.  Omar  Kh. A. 《Geotectonics》2020,54(5):713-722

Geotectonics - Aswan region is a very important region for Egypt where the High Dam is situated. The wellbeing of the dam and its encompassing region is of extreme worry to all the Egyptian...  相似文献   

B.S. Daya Sagar,Qiuming Cheng and Frits Agterberg: Handbook of Mathematical Geosciences: Fifty Years of IAMG     

Kostyuchenko  Yuriy  Abioui  Mohamed  Di Cencio  Andrea 《Mathematical Geosciences》2020,52(5):725-729

Mathematical Geosciences -  相似文献   

Finite strain analysis for deformed Neoproterozoic rock associations of the Al Amar fault zone,Eastern Arabian Shield,Saudi Arabia     

Mohammed  Lami Abdel Karim Nouaman  Kassem  Osama Mohamed Kaoud  Al Bassam  Abdel Aziz Mohamed 《Arabian Journal of Geosciences》2020,13(6):1-6

Arabian Journal of Geosciences - In this work, quantitative analysis of coastal zone landform morphology is carried out through the integration of landscape index, remote sensing (RS) and...  相似文献   

Compositional Variations and Tectonic Settings of Podiform Chromitites Associated with Ultramafic Rocks of the Pan-African Proterozoic Ophiolites from South Eastern Desert, Egypt     

Mohamed Metwaly ABU ANBAR  Fernando GERVILLA 《《地质学报》英文版》2020,94(Z1):40-42

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Component Analysis and Antifungal Activity of the Compounds Extracted from Four Brown Seaweeds with Different Solvents at Different Seasons     

Soad M. Mohy El-Din  Mohamed M. Mohyeldin 《中国海洋大学学报(英文版)》2018,17(5):1178-1188

The polar and nonpolar extracts of Colpomenia sinuosa, Padina pavonia, Cystoseira barbata and Sargassum vulgare collected during spring, summer and autumn were evaluated for their antifungal activities. The phytochemicals of unexplored seaweeds were analyzed by gas chromatography and mass spectrometric (GC/MS). The algal extracts were tested for their antifungal activities against Aspergillus niger, A. flavus, Penicillium parasiticus, Candida utilis and Fusarium solani. Phytochemicals were extracted from the four seaweeds with various solvents including methanol, ethanol, acetone, chloroform and dimethyl ether. Among the various extracts, methanolic extract showed the highest inhibition activity on all fungal species. Seasonal variation in antifungal activity was studied, while methanol extracts showed the best antifungal activity in spring. Cystoseira barbata was the most effective seaweed, having antifungal activity throughout the whole year. The UV-Vis phytochemical procedure and GC-MS analysis of the methanol extracts from tested species indicated the existence of different constituents. In conclusions, the compounds with antifungal activity were identified as indoles, terpenes, acetogenins, phenols, and volatile halogenated hydrocarbons.  相似文献   

Comparison of Satellite Altimetric Gravity and Global Geopotential Models with Shipborne Gravity in the Red Sea     

Ahmed Zaki  Ahmed Hamdi Mansi  Mohamed Selim  Mostafa Rabah  Gamal El-Fiky 《Marine Geodesy》2018,41(3):258-269

The determination of high-resolution geoid for marine regions requires the integration of gravity data provided by different sources, e.g. global geopotential models, satellite altimetry, and shipborne gravimetric observations. Shipborne gravity data, acquired over a long time, comprises the short-wavelengths gravitation signal. This paper aims to produce a consistent gravity field over the Red Sea region to be used for geoid modelling. Both, the leave-one-out cross-validation and Kriging prediction techniques were chosen to ensure that the observed shipborne gravity data are consistent as well as free of gross-errors. A confidence level equivalent to 95.4% was decided to filter the observed shipborne data, while the cross-validation algorithm was repeatedly applied until the standard deviation of the residuals between the observed and estimated values are less than 1.5 mGal, which led to the elimination of about 17.7% of the shipborne gravity dataset. A comparison between the shipborne gravity data with DTU13 and SSv23.1 satellite altimetry-derived gravity models is done and reported. The corresponding results revealed that altimetry models almost have identical data content when compared one another, where the DTU13 gave better results with a mean and standard deviation of ?2.40 and 8.71 mGal, respectively. A statistical comparison has been made between different global geopotential models (GGMs) and shipborne gravity data. The Spectral Enhancement Method was applied to overcome the existing spectral gap between the GGMs and shipborne gravity data. EGM2008 manifested the best results with differences characterised with a mean of 1.35 mGal and a standard deviation of 11.11 mGal. Finally, the least-squares collocation (LSC) was implemented to combine the shipborne gravity data with DTU13 in order to create a unique and consistent gravity field over the Red Sea with no data voids. The combined data were independently tested using a total number of 95 randomly chosen shipborne gravity stations. The comparison between the extracted shipborne gravity data and DTU13 altimetry anomalies before and after applying the LSC revealed that a significant improvement is procurable from the combined dataset, in which the mean and standard deviation of the differences dropped from ?3.60 and 9.31 mGal to ?0.39 and 2.04 mGal, respectively.  相似文献   

马来半岛彭亨河和吉兰丹河沉积物稀土元素特征及其物源示踪     

吴凯凯  刘升发  金爱民  楼章华  吴斌  李景瑞  张辉  方习生  Che Abd.Rahim Bin Mohamed  石学法 《海洋学报》2019,41(7):77-91

通过对马来半岛东部彭亨河28个站位和吉兰丹河22个站位表层沉积物进行稀土元素（REE）测试,对比分析了稀土元素的组成特征和分布规律,探讨了稀土元素组成的控制因素和物源示踪意义。结果表明,彭亨河沉积物稀土元素含量介于24.88～304.29 μg/g之间,平均含量为165.22 μg/g,吉兰丹河沉积物中稀土元素含量介于126.02～281.40 μg/g之间,平均值为181.15 μg/g。彭亨河大部分沉积物上陆壳(UCC)标准化模式为重稀土相对轻稀土富集,吉兰丹河沉积物轻重稀土无明显分异。沉积物源岩和矿物组成对两条河流的REE组成起到了重要的控制作用,化学风化对彭亨河REE组成的影响大于吉兰丹河,而彭亨河沉积物粒度组成显著差异也导致了其REE含量变化范围更大。δEu_UCC-(Gd/Yb)_UCC关系图中彭亨河和吉兰丹河沉积物分区明显,表明其可作为定性判别两条河流来源的有效指标,并可用于海区沉积物来源的示踪和定量识别。  相似文献   

Copepod community structure during upwelling and non-upwelling seasons in coastal waters off Cochin, southwest coast of India     

Job N Jemi  Mohamed Hatha A. A. 《海洋学报(英文版)》2019,38(12):111-117

Vypeen, an island of Cochin estuarine system, acts as the spawning site of several marine and estuarine fishes. We assumed that, physical process(upwelling) make changes in hydrography and the production of chlorophyll a in coastal waters off Vypeen. These alterations can influence the zooplankton abundance and copepod community structure in that area. For justifying this hypothesis, samples were collected from Vypeen at 10 m and 30 m locations during January(pre-southwest monsoon), August(late-southwest monsoon) and November(postsouthwest monsoon) 2014. During August, subsurface water column was cool, nutrient rich and less oxygenated(signatures of upwelling) than in November and January. Maximum concentrations of nitrate and chlorophyll a were recorded during August. In the present study, 15 zooplankton groups were recorded; of which copepods were the most predominant group(73%–90%). Copepod density in the present study ranged between 527.2 ind./m~3 and 5 139.2 ind./m~3. Totally, 37 copepods species were reported in present study and copepod species richness was higher during January. The abundance of zooplankton and copepods was high in August during late-southwest monsoon. These variations were closely associated with the coastal upwelling in August and weakening of moderate upwelling in November. In SIMPER analysis, it was found that the copepods species distribution was similar within season and dissimilar between the three seasons. Moreover, the higher abundance of upwelling indicator species Temora turbinata was recorded in August, which confirms the signs of seasonal upwelling in Vypeen. The present study emphasized on the influence of hydrographical parameters associated with physical process, in governing the copepod community organization of the Vypeen Island.  相似文献   

Rare Earth Elements Around the Barakah Nuclear Power Plant,UAE     

Al Rashdi  Mouza Rashid  El Tokhi  Mohamed  Alaabed  Sulaiman  El Mowafi  Walid  Arabi  Alya A. 《Natural Resources Research》2020,29(6):4149-4160

Natural Resources Research - Rare earth element (REE) contamination has major consequences for the environment and humans. Some forms of REEs have more serious environmental impacts than others. It...  相似文献   

Atmospheric Water Harvesting from Low-Humid Regions of Hail City in Saudi Arabia     

Elashmawy  Mohamed  Alatawi  Ibrahim 《Natural Resources Research》2020,29(6):3689-3700

Natural Resources Research - Atmospheric water harvesting (AWH) is emerging as a promising technique of water production in remote and isolated areas away from natural water resources. The present...  相似文献